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    31 December 2000, Volume 21 Issue S1
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    Plenary Lectures
    Noninear Optical Spectroscopy for Studies of Surfaces
    SHEN Yuen-Ron
    2000, 21(S1):  1-1. 
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    Infrared-visible sum-frequency generation has been developed into a powerful vibrational spectroscopic tool to study surfaces and interfaces. It is highly surface-specific and sensitive in media with inversion symmetry, and therefore has found many unique applications in areas that have not been well explored. We discuss here a few examples including liquids and polymers. We show that the observed surface vibrational spectra allow us to obtain information about surface structures of liquids and polymers. While such information is often qualitative, it is possible in some better prepared cases to deduce quantitative details about molecular orientation and alignment at the surface.

    Recent Development in Radiationless Transitions
    LIN Sheng-Hsien
    2000, 21(S1):  2-2. 
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    Radiationless transitions consist of internal conversion, a spin-allowed electronci relaxation, and intersystem crossing, a spin-forbidden electronic relaxation. The historical development of radiationless transitions will be briefly reviewed.I will then discuss the importence of Duschinsky effect on the radiationless transitions of intermediate size molecules like ethylene. Ab initio calculations of the internal conversion in ethylene will be demonstrated. Sub-picosecond internal conversions have been observed to take place in the photosynthetic bacterial reaction centers. In this case,vibrational relaxation is not faster than internal conversion and thus "temperature" has no meaning in this case. I will show how to theoretically treat these ultrafast nonradiative processes.

    Inorganic Photochemistry:Past, Present, and Future
    CHE Chi-Ming
    2000, 21(S1):  3-3. 
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    Transition metal complex, in its electronic excited state, has intriguing photophysical and photochemical properties that are substantially different from its ground state, Indeed, electronically excited metal complex can be viewed as hot chemical species that is readily synthesized by photo-excitation with UV-visible light. If the energy of excited metal complex can be properly manipulated, it may be possible to devise new catalytic system for converting light to chemical energy. In the context of energy conversion reactions and chemical sensing, it is important for biomolecular reactions at room temperature. Among the photochemical bimolecular reactions, the following three have the widest applications in photocatalysis, and these are (1) bimolecular outer-sphere electron transfer reactions, (2) bimoleculat inner-sphere atom transfer/abstract reactions, and (3) exciplex formation involving electronic excited state. The past of inorganic photochemistry has demonstrated the success of[Ru(bpy)3]2+ as a powerful reagent for light-induced electron transfer reactions. Much of the current photochemistry research focus on coordinative unsaturated metal complexes, that are strongly photoluminescent and readily undergo substrate binding reactions in their excited states. In this lecture, I will review some of the past successful stories of[Ru(bpy)3]2+ and discuss our current research on the luminescent metal-complexes prepared in my laboratory. I will end my lecture by proposing a clue for achieving light-induced multi-electron transfer reactions, which remains a challenge in photochemistry research.

    Towards Predicting the Magnitude and Direction of Radical Substituent Effect:The Importance of Polar Interaction in Radical System
    CHENG Jin-Pei
    2000, 21(S1):  4-4. 
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    Substituent effect of reactive intermediates has long been a central issue in organic chemistry[1]. While quantitative knowledge on structure-property relationship of close-shell species (e.g., carbanions, carbocations, and neutral molecules, etc.) has already been well documented in the literature and textbooks, the present understanding of substituent effect on radicals is still largely limited to the information drawn basically from the (σ and BDE (bond dissociation energy) studies of a single family, the benzyl radical[2]. Naturally, the general applicability of these scales as indicators of radical stability to other families bearing different structural features needs to be examined. The present systematic experimental and computational investigation on radicals of the benzylic type centered on carbon atoms of vaiying degree of electronegativity shows that i) there are actually three (rather than one as previously well claimed) basic patterns of radical substituent effect for carbon radical; and ii) prediction of the direction and magnitude of radical substituent effect should be workable on the basis of quantitative understanding of polar interactions within a radical system[3]. Experimental evidence and detailed analysis on this respect are presented.

    Analytical Sciences
    Molecular Design of Luminescent Metal-Based Materials
    Vivian Wing-Wah YAM
    2000, 21(S1):  5-5. 
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    Polynuclear transition metal complexes have been shown to exhibit rich luminescence behavior. The recent reports on the potential applications of alkynyl metal complexes as nonlinear optical materials, molecular wires and rigid-rod materials, and the wide variety of possible bonding modes of the alkynyl moiety have aroused our interest in investigating their potential in the design and synthesis of di- and polynuclear metal complexes. In this presentation, the design and successful isolation of a series of soluble di- and polynuclear transition metal acetylides with rich luminescence behavior will be described11,21.

    Towards Total Quality Management of Chinese Medicinal Herbal Products:A Case Study of Danshen (Radix Salvia Miltiorrhiza)
    LEE Frank S. C., WANG Xiao-Ru
    2000, 21(S1):  6-6. 
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    The global trend of favoring therapeutic treatment and health keeping with natural medicine and dietary supplement/neutraceuticals provides golden opportunity for the re-birth of CM (Chinese Medicine) and its integration into the mainstream health care system worldwide. To develop a scientifically sound and technology-based CM industry in order to compete favorably in the world market, one needs to modernize the entire process of CM manufacturing from raw material supply to downstream product preparations. High quality and contaminant-free raw material produced under GAP (Good Agriculture Practice) guidelines is the first step leading eventually to the production of quality and safe CM products through a series of quality guidelines including GLP (Good Laboratory Practice) for chemical analysis,GcLP (Good Clinical Laboratory Practice) for clinical testing, GMP (Good Manufacturing Practice) for product manufacturing, and finally GSP (Good Sales Practice) for business transactions. These 5 P's in essence constitute the TQM (Total Quality Management) system for product development.

    Development of Optical Sensors Based on Luminescent Transition-Metal Complexes
    WONG Kwok-Yin
    2000, 21(S1):  7-7. 
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    Luminescence-based optical sensors are becoming increasingly important particularly in the area of fibber optic sensors. Most luminescence sensors detect analyses based on the change in luminescent intensity or excited-state lifetime of the sensing material as a function of analyst concentration. Luminescent materials with long excited-state lifetime are essential for the development of inexpensive sensors because it is much simpler and less expensive to measure lifetime in microseconds than in nanoseconds. Luminescent dyes with absorption in the visible region would allow the use of inexpensive light sources such as light emitting diodes (LEDs). Recent studies indicate that luminescent transition metal complexes, especially those with platinum group metals, have desirable spectral characteristics and features including long excited state lifetimes, high luminescence quantum yields and intense visible absorptions. They also tend to be thermally, chemically and photochemically robust. We have been investigating new luminescent sensor materials with the aims to understand the behaviour of luminescent materials in polymer and gel support and to develop new sensor materials with desirable properties.

    New Trial to Attack the Problems in Analysis of Saccharides with Surface Plasmon Resonance
    CHEN Yi, WANG Zhen, WANG Xiao-Yan, WANG Yu-Jie, LI Zhong
    2000, 21(S1):  8-8. 
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    It remains a big challenge how to overcome the detection and separation problems of carbohydrates. To further reveal their bio- and chemo-functions, exploration of new methodology is one of the key steps. For this purpose, surface plasmon resonance (SPR) was considered and has since been tried. This is a surface-sensitive spectroscopic technique and samples with different polarities can be measured without any chromophore. In this presentation we will show that SPR is a promising technique suitable for both of identification and quantification of sugars.

    Sequence Pattern Correlation of Amino-Acid in Collision-Induced -Dissociation Electrospray Ionization Mass Spectrometry
    SONG Hao-Wei, YUE Gui-Hua, LU Yu, WEI Ying, WANG Hong-Hai, YANG Peng-Yuan
    2000, 21(S1):  9-9. 
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    Briefly, the experimental mass spectrum is defined as X(i)(#em/em#=1,2,...n)and the guessed sequence pattern in an estimated order is defined as Y(k) (k=1,2,...n). For the discrete signals in mass spectra, the cross-correlation coefficient of Cxy,can be then given by.

    A High Performance Sensor for L-ascorbic Acid Based on Electrode Modified With Chromium(Ⅲ)-Tetra(4-N,N,N-Trimethylanilinium)-Porphyrin
    WANG Bao-Xing, LI Xiao-Yuan
    2000, 21(S1):  10-10. 
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    L-ascorbic acid (AA) or Vitamin C is one of the most important water-soluble antioxidants and cellar redox-regulator. It is required widely in biological metabolism and is one of the most frequently taken vitamins to supplement inadequate dietary intake. Therefore, there has been wide demand in food and pharmaceutical industries and in nutritional assessment for the development of selective, simple, accurate and rapid technique to determine AA.

    Ion Channels as Sensing Elements-Investigations by Patch-Clamp Technique
    LI Jie, RAUTENBERG Claudia, FRIEDRICH Steffen, SALZER Reiner
    2000, 21(S1):  11-11. 
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    Ion channels are transmembrane proteins. Their high recognition capability together with an intrinsic amplification effects makes them outstanding candidates as constituents of biosensors. The patch-clamp technique is an extremely powerful and versatile method for studying the functioning of ion channels reconstituted into biological or synthetic membranes. Two well characterized types of natural ion channels were studied, (i) the simple transmembrane protein gramicidin A and (ii) the rather complex ligand-gated nicotinic acetylcholine receptor.

    Speciation of Rare Earth Elements in Soil by HPLC-ICP-MS
    WANG Oiu-Quan, GUAN Zhen-Wei, HUANG Ben-Li, YANG Chao-Yong, WANG Xiao-Ru
    2000, 21(S1):  12-12. 
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    Elemental speciation is one of the growing features of analytical chemistry of recent two decades. It is now widely recognized that the determination of total trace element contents is no longer sufficient for evaluating their pathways,environmental and biological effects, which mainly depend on their specific chemical forms existing in the samples. On the other hand, rare-earth elements (REEs), which have their unique properties, have recently been used in many fields of industry, and agriculture especially in China for increasing the crop's production. Up to now, the amount of REEs used in agriculture is more than 1000 tons per year in China.1Such a great amount of "foreign" REEs is annually applied to the environments, what is the effect of the "foreign" REEs to the environments except the increase production brought? Moreover, how is the biological effect to living things including human beings after eating the food? To answer such questions, the speciation of REEs has a special significance.

    Direct Electrochemical Study of the Redox Species in RC Protein and its Mutants Immobilized in Self-Assembly Monolayers
    CAO Yi-Bin, CHEN Dan-Dan, WU Xing-Liang, KONG Ji-Lie, ZOU Yong-Long, XU Chun-He
    2000, 21(S1):  13-13. 
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    4-Aminothiophenol (4-ATP) self-assembled monolayer (SAM) was immobilized on gold electrode. The multi-layered protein film electrode was prepared to rinse the 4-ATP-Au electrode in poly-styrenesulfonate (PSS) and poly-dimerthyldiallylammonium chloride (PDDA) successively, then soaked in a solution containing photosynthetic reaction center (RC) protein from Rhodobacter sphaeriodes or its pigment-replaced mutant. Thus, RC was found embedded in an ordered-orientation film. In cyclic voltammetry (CV) and square wave voltammetry (SWV), Au electrode gave a series of electrochemical signals due to the redox reaction of RC protein or its mutants. Intermolecular direct electron transfer (ET) was studied in this work.

    Controlling the Bonding Site of Photosynthetic Reaction Centers on Au Electrode by Different Bifunctional Agents
    ZHAO Jie-Quan, LIU Bao-Hong, WU Xing-Liang, KONG Ji-Lie, ZOU Yong-Long, XU Chun-He
    2000, 21(S1):  14-14. 
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    The orientation of the immobilized protein is the key factor to effect the surface electrochemistry of the redox couples therein. The photosynthetic reaction centers (RCs) composite film was fabricated by self-assembled monolayers (SAMs) on Au electrode. The bifunctional reagents e.g. 4-aminothiophenol (ATP), 2-mercaptoehtylamine (MEA), 2-mercaptoethanol (ME), 2-mercaptoacetic acid (MAA), and Poly(dimethyldiallylammonium) chloride(PDDA) were found to bond RCs at different sites. The square wave voltammetry (SWV), bulk electrolysis were employed for characterizing the composite film. The electrochemically-driven electron transfer (ET) behavior in films was found driven by SWV or bulk electrolysis. In case the electrode was modified directly by amino compound reagent, the greater force was needed. If the film was activated by SWV with frequency of 15 Hz, the SWV amplitude of about lOOmV for MAA-PDDA-RC and 250 mV or more for MA-RC film was needed respectively. When the ME-PDDA-RC composite film was stimulated by SWV, the peak for the bacteriochlorophyll dimmer (P) and secondary quinone (QB) appeared at first, then the peak of primary quinone (QA) came into being. Further more,if the simulated signal of SWV was continually applied, all of the peak current increased. On the other hand, the opposite process was observed while the potential of -0.4 V was applied by bulk electrolysis. For all the composite films,the redox potential for P+/P declined with frequency increasing from 30 to 150 Hz.As reported before, the redox potential of species in RC were:0.45-0.60 V (vs.NHE)for P+/p, +0.05~-0.15 V for QA and -0.20~-0.35 V for QB.

    Spectro-Electrochemistry of Photosynthetic Reaction Centers in Coulombically Linked Self-Assembled Monolayers
    ZHAO Jie-Quan, LIU Bao-Hong, WU Xing-Liang, KONG Ji-Lie, ZOU Yong-Long, XU Chun-He
    2000, 21(S1):  15-15. 
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    Bio-mimic photosensitive composite films were prepared by linking the monolayer of the photosynthetic reaction centers (RCs) with bifunctional reagents (e.g. 2-mercapto-ethylamine, thiourea) on an Au electrode via Au-S bonding. Square wave voltammetry (SWV), bulk electrolysis, and in-situ CCD spectra were employed for the characterizing the composite films. The composite film behaved reversible or quasi-reversible electron transfer in pH 8.0 tris-HCl buffer. Three peaks were observed centered at 0.468 V,-0.08 V and -0.32 V(vs. NHE) respectively in the potential window from 0.6 V to -0.4 V at low frequency (5-15Hz). Besides, a reproducible peak current fluctuation was observed, i.e. the second and the third peaks disappeared progressively while the first peak increased with the SWV frequency going up, and the electrochemical reaction corresponding to the first peak changed from quasi-reversible to reversible. Three redox couples in RCs, P*/P (the bacteriochlorophyll dimmer, the primary doner), QA-/QA (Primary quinone) and QB-/QB(second quinone) were assigned to contribute to the three reduction peaks respectively. The linear relationship of peak current vs. scanning rate for peak l(i.e. P*/P peak) also showed the reaction of RC in agree with a fast thin-film voltammetric behavior, which implied that the RCs monolayer is linked effectively to the electrode surface.

    Monitoring the Electrochemical Deposition of an Eletrochromic Film and Its in-situ Electrochromism Behavior by a CCD-Spectrophotometer
    TANG Jia, ZHAO Jie-Quan, KONG Ji-Lie
    2000, 21(S1):  16-16. 
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    Among the transition metal oxides &at exhibits electrochromic properties, thin-film MoO3, has been widely studied in recent 20 years, due to its quick response, high coloration efficiency, low start-up potential and long maintenance state without work consumption. This paper introduces a new experimental approach which study the electrochromic properties of MoO3 with time-resolved in-situ CCD spectrophotometer.

    BOD Biosensor Fabricated with Sol-Gel Membrane
    CHEN Dan-Dan, CAO Yi-Bin, LIU Bao-Hong, LIU Zhen-Jiu, KONG Ji-Lie
    2000, 21(S1):  17-17. 
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    A novel BOD biosensor fabricated with the microbial membrane on an oxygen electrode was introduced by using porous A12O3 sol-gel inorganic matrix to immobilize the yeast, which is convenient, rapid, correlating to the results of BOD5 and could be employed for commercial availability in the future. The induced culture technique was used to obtain high active yeast, and this point especially contribute to the higher selectivity and sensitivity, The gelation time to form microorganisms membrane is about 1 h, and the response time is 20min, the response current is steady rapidly, a linear relationship between the response of the sensor and BOD value ranging from 10~70 mg/L, the reproducibility of BOD estimation is good and the lifetime of BOD biosensor is over 30 day at 4℃.

    Aluminum Sol-Gel Immobilized Amperometric Biosensor for H2O2
    ZHAO Bin, CHEN Dan-Dan, ZHAO Jie-Quan, KONG Ji-Lie, LIU Bao-Hong
    2000, 21(S1):  18-18. 
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    The determination of hydrogen peroxide is of practical importance in chemical, biological, clinical and many other fields. Enzyme electrodes have been studied widely for the past two decades and many research papers have been devoted to them. A very important factor in enzyme electrode development is the enzyme immobilization. Since Braun et al reported the first attempts to encapsulate proteins inside silica glasses in 1990, the low temperature sol-gel process has become an attractive avenue for the immobilization of biomolecules in connection with the development of new biosensors. A sufficient amount of trapped interstitial water contained in gels played an important role in the retention of the tertiary structure and reactivity of the immobilized enzymes.

    Employing Phenazine Methosulphate as an Electron Shuttle Incorporated in an Al2O3 Sol-Gel Matrix for a Tyrosinase Biosensor
    LIU Bao-Hong, ZHAO Jie-Quan, CAO Yi-Bin, KONG Ji-Lie, DENG Jia-Qi
    2000, 21(S1):  19-19. 
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    Currently, porous inorganic xerogels are particularly attractive matrices for electrochemical biosensors since they combine physical rigidity, negligible swelling in aqueous solutions, chemical inertness, and high photochemical, biodegradational, and thermal stability. The process parameters can be selected to provide an effective matrix to entrap the enzymes, which can retain their functional characteristics and activity to a large extent. The porosity in the sol-gel matrix plays an important role for the selective and effective interaction between the entrapped enzyme and substrate in the sample milieu.

    Study on the Electrochemical Behavior of Melatonin with Modified Electrode
    WU Xiao-Ping, LIAO Wen-Rong, DUAN Jian-Ping, CHEN Hong-Qing, CHEN Guo-Nan
    2000, 21(S1):  20-20. 
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    Melatonin, N-acetyl-5-methoxytryptamine, is an indoleamine hormone synthesized in the pinealocytes. It has been considered as a time-keeping hormone at the biological clocks and was found to play central role in cell protection[1]. Melatonin in biological samples can be detected by several methods, such as HPLC, UV, fluorimetry and radio-immunoassay. However, only a few studies dealing with its redox behavior have been reported[1-3]. The aim of the present study is to use the activating electrochemical modified glassy carbon electrode(MGCE) for the preconcentration and trace determination of melatonin.

    Microtribological Studies of Poly(ether ether ketone) by Atomic Force Microscopy (AFM)
    HAN Yan-Chun,SCHMITT Stefan, FRIEDRICH Klaus
    2000, 21(S1):  21-21. 
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    Atomic force microscopy (AFM) and its modification-lateral force microscope (LFM) are becoming increasingly important in the understanding of microfriction and nanomechanical property measurements. In the present paper, the AFM, LFM and a modified AFM-lithography technique are described, and data on microtribilogical studies of PEEK are presented. For comparisons, macro-scale friction measurements were also made on PEEK by the use of a block-on-ring testing facility. It was observed that macro-scale friction is higher than that on the microscale. Lower value of micro-scale friction as compared to macro-scale fiction may be because of less ploughing contribution in the micro-scale measurement.

    Separation of Compounds in Traditional Chinese Medicines Using Comprehensive Two Dimensional Chromatography
    ZHANG Xiang-Min. HU Hua-Ling, XU Shao-Ying, HUANG Shuang
    2000, 21(S1):  22-22. 
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    Traditional Chinese medicine is an invaluable treasure of the Chinese nationalities. Thousands of natural species that are of pharmaceutical importance have been accumulated. Most of them are plants. Traditional Chinese medicines generally are of unusual complexity. Even a single medicinal material may contain hundreds of compounds. Since these compounds play cooperative roles pharmacologically, it is essential to analyze all compounds as a whole. It is also important for quality controls in each step of productions, such as raw material collection, processing, and manufacturing. A comprehensive two-dimensional separation system coupling capillary high performance liquid chromatography with fast capillary electrophoresis (μ-HPLC-CE) is developed to provide a powerful means to separate such complex samples. In the first dimensional separation, a home-packed micro-HPLC column was used to reduce the consultation of sample injection and avoid sample dilution. The second dimensional analysis was carried out by micellar electrokinetic chromatography(MEKC) considering the fact that most compounds in Chinese medicine are neutrals. In order to achieve high-speed separation^ theory of fast MEKC was extensively studied. Models of the fast MEKC migration behaviors were established. Relationships of theoretical plates vs. electric field strength and column length were derived. It is concluded that maintaining certain column length and applying high-voltage at the ends of the capillary simultaneously are the key points to achieving fast MEKC separation. A pulse-contacting interface was developed for the 2-D μ-HPLC-CE system. CE sampling was carried out in an instant contact of HPLC and CE columns in an optimized timing program. During the short contact period, a certain fraction of HPLC effluent was introduced into the CE capillary. Injection efficiency for such an interface was up to 81%. Relative standard deviation (RSD) of migration times and peak heights for 100 consecutive MEKC. separation were 3.0% and 1.8%, respectively. With this novel 2-D μ-HPLC-CE system, some traditional Chinese medicines were analyzed and hundreds of peaks were observed. For liquorice, over 110 components were fairly resolved. More than 250 peaks were obtained for a compound mixture of Cheng-Qi-Tang. The peak capacity of this novel comprehensive 2-D HPLC-CE system was estimated to be about 2400 in 80 min.

    Matrix Isopotential Synchronous Fluorescence Spectroscopy for Direct Determination of 1-Hydroxypyrene as a Urinary Biomarker of Exposure to Polycyclic Aromatic Hydrocarbons
    LI Yao-Qun, SUI Wei, WU Chun, YU Li-Jun
    2000, 21(S1):  23-23. 
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    Polycyclic aromatic hydrocarbons (PAHs) are present ubiquitously in the environment and exposure to PAHs is a major environmental and occupational health problem. One important approach in assessing human exposure to PAHs is to measure 1-hydroxypyrene excreted in urine. Its present analytical methods require either chromatographic separation[1] or solvent extracting[2]. Matrix isopotential synchronous fluorescence spectroscopy (MISFS) is a new fluorimetric technique which consists of performing synchronous scans through a trajectory joining points of equal intensity on a total fluorescence spectrum[3]. The technique is very useful for resolving highly-spectrally-overlapped mixtures or detecting analytes in complex fluorescent background without the need for tedious prior separation.

    A Pyrolysis Method Combined with Atomic Absorption Spectrometry for the Direct Determination of Total Mercury Concentration And Mercury Species in Traditional Chinese Medicine (TCM) Samples
    CHEN Bin, WANG Xiao-Ru
    2000, 21(S1):  24-24. 
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    Alarm has been heightened internationally in recent years to control the contents of metals such as Cd, Pb, As and Hg and other toxic contaminants in CM products. Among these elements, mercury is receiving more attrition not only because of contamination, but also because of its use often as an active CM ingredient. The quality, efficacy, and safety of CM products related to these elements have to be critically assessed before the products can be put in clinical trials or placed on the market. It is now well recognized the mercury is a toxic element, regardless of inorganic or organic species. The toxicity of mercury depends on both its concentration and chemical forms. Because of the great differences in toxicity and bioavailability between organic/inorganic and the other chemical forms of mercury, there is a strong need to develop analytical methodologies for mercury speciation analysis.

    Inductively Coupled Plasma-Mass Spectrometry (ICP/MS) Based Methodology for Metal Speciation Analysis in Chinese Herbal Medicine
    WANG Xiao-Ru, HU Guang-Lin, CHEN Bin, CHEN Den-Yun, ZHUANG Zhi-Xia Frank S. C. LEE, LEUNG Hei-Wun, YEUNG Hin-Wing, C. W. MCLEED
    2000, 21(S1):  25-25. 
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    One of the major problems in marketing Chinese Medicinal (CM) material product is the issue of product safety. Alarm has been heightened internationally in recent years to control the contents of metals such as Cd, Pb, Hg and As and toxic contaminants such as residue pesticides in CM product. Cases of severe and fatal poisoning have occurred after the consultation of contaminated CM products, or adulterated ones containing toxic substitutions. Such incidences have severely damaged the overall image of CM products. It therefore comes as no surprise that in the recommendations put forward recently in China, the control of metals and toxic contaminants in CM products is a top priority item requiring proper action.

    Electrochemiluminescence Behavior of Humic Acid
    CHEN Xi, LI Zhen, ZHAO Li, WANG Xiao-Ru
    2000, 21(S1):  26-26. 
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    Humic substance, which interact strongly with toxic heavy metals[1] and may be precursors of trihalomethane (THM) formed during water treatment with chlorine, are the major organic constituents of fresh water, sea-water and soils. Humic acid (HA) has a very complex structure and an accurate concentration is very difficult to determine.

    Ammonia-Sensitive Rubbery Ormosils Materials
    CHEN Xi, DAI Yuan-Jing, LI Wei, ZHUANG Zhi-Xia, WANG Xiao-Ru
    2000, 21(S1):  27-27. 
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    Generally, conventional sol-gels are rather hydrophilic and well suited for sensing some ions such as H+. A more hydrophobic material for ammonia sensing ormosils materials can be obtained by preparing organically modified siloxanes ormosils. When dimethyldimethoxysilane (DiMe-DMOS) is mixed with an alkoxide such as tetramethoxysilane (TEOS) in a suitable soluent and catalyst, gels can be prepared which exhibit rubbery elasticity.

    Determination of Organochlorine Pesticide Residues in Ganoderma Lucidum (Lingzhi) using Accelerated Solvent Extraction and Gas Chromatography with Electron Capture Detector
    HU Guang-Lin, WANG Xiao-Ru, Frank S.C. LEE
    2000, 21(S1):  28-28. 
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    The residues of organochlorine pesticides (OCPs) may occur in Chinese herbal medicines (CHMs). It is needed to analyze CHMs for OCPs to evaluate the risk of CHMs to the health of consumers. The common technique for sample preparation in OCPs determination is Soxhlet extraction[1], which is time-consumable. Meanwhile, up to the present, no standard methods have been reported exactly for the determination of OCPs in Chinese medicines. The goal of the present research is to establish an analytical method suitable for the separation and determination of OCPs in Ganoderma Lucidum (lingzhi) and it's products.

    An Optical pH Sensor with a Linear Response over a Broad Range Based on Organically Modified Silicate Film
    LI Wei, CHEN Xi, ZHUANG Zhi-Xia, SUN Da-Hai, WANG Xiao-Ru
    2000, 21(S1):  29-29. 
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    Sol-gel technology provides a viable approach to prepare stable, optically transparent host matrices for the design of materials for sensor, optical, chromatographic, and catalytic applications[1] Alternatively, organosilicon precursors of the general formula can be hydrolyzed and cocondensed with tetraethoxysilane to form an organic-inorganic hybrid. An aliquot of the resultant sol can be spin cast or dip coated on a planar substrate to form a thin film.

    A Fiber Optic Chemical Sensor with Pyrenebutyric Acid as Sensing Material for Dissolved Oxygen
    LI Wei, CHEN Xi, ZHUANG Zhi-Xia, SUN Da-Hai, WANG Xiao-Ru
    2000, 21(S1):  30-30. 
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    Oxygen sensors are used extensively in various fields to determine the oxygen concentration. Amperometric determination of molecular oxygen in water using Clark-type electrodes is widespread, but recent advances in fiber optic technology, light sources and detectors have boosted the development of oxygen sensors based on fluorescence quenching of suitable indicators by oxygen[1,2]. In situ, reversible, electrical-free, highly sensitive, specific measurements can be performed in real time using on-line fiber optic monitors, with a potential bonus of increased resistance toward chemical and biological attack.

    Electrochemiluminescent Determination of Methamphetatiime
    LI Mei-Jin, CHEN Xi, WANG Xiao-Ru
    2000, 21(S1):  31-31. 
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    Methamphetamine (MAPA) is a kind of anesthesia, which determination is paid more attention to recently. MAPA has been determined by GC, GC-MS, polarization fluoroimmunometry,HPLC and capillary zone electrophoresis (CZE)[1] and so on. There is still a need for rapid, inexpensive but sensitive methods for the determination of drugs.

    Chemiluminescent Determination of Inorganic Phosphate
    JIANG Ya-Qi, LI Zhen
    2000, 21(S1):  32-32. 
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    Flow injection (FI) chemiluminescence (CL) analysis has received much attention in various fields for its high sensitivity, rapidity, simplicity and feasibility. Recently, interest has also focused on the use of FI in site monitoring of environmental materials in surface and sea water, such as phosphate. Most of the commonly used methods for the determination of inorganic phosphate by FI are based on spectrophotometric measurement of the phosphomlybate or phosphomolybdovanadate complex[1], or fluorescence quenching methods using metals, such as aluminium-morin (Al-morin) system[2]. A new CL determination of inorganic phosphate by FI system is described (Fig 1).

    Optical Sensing System for Monitoring Nitrogen Dioxide
    JIN Xing-Liang. LI Wei, SUN Da-Hai, ZHUANG Zhi-Xia, CHEN Xi, WANG Xiao-Ru
    2000, 21(S1):  33-33. 
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    Coloration reactions occurring in the pores of porous glass for the detection of NO2 were reported by Tanaka et al[l] and NO2 sensing system based on sol-gel film was depicted by Worsfold et al[2]. In this work, Sulfanilamide(SFA) and N,N-dimethyl-1-naphthylamine, (DMNA) entrapped in an organically modified silicate film, were employed as the diazonzing reagent and the coupling reagent, individually, to detect nitrogen dioxide. The sample gas was prepared by diluting standard NO2 gas with dry N2. The coloration reagents were immobilized in the silicate films first. Then the sensing film was exposed to NO2 in air for ten days.

    Sol-Gel-derived Film for Oxygen Sensor
    HONG Jiang-Xing, LI Wei, CHEN Xi, ZHUANG Zhi-Xia, SUN Da-Hai, WANG Xiao-Ru
    2000, 21(S1):  34-34. 
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    Oxygen concentration is an important parameter in environmental, chemical and other fields. Oxygen sensor based on luminescence quenching by oxygen have been developed and wide applied. The oxygen quenching process is described by the Stern-Volmer equation. Ruthenium complex are chosen as fluorescence indicator because they are particularly attractive for oxygen sensing, exhibit high luminescent quantum yield, long excited-state lifetime, large Stokes shift, and strong absorption in the blue-green spectral region[1]. The sensor involves immobilizing the ruthenium complex within a porous sol-gel-processed film. Sol-gel process has many advantages as a method of immobilization. At ambient temperature, it allows the fabrication of a tough, inert, porous glass material with a high surface area. Sol-gel-derived silica film has a low optical absorption in the visible and UV region of the spectrum and is relatively inexpensive to produce[2].

    The New Method of Variable Selection
    ZHUEr-Yi, ZHUANG Zhi-Xia
    2000, 21(S1):  35-35. 
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    The selection of variables is very important in order to build the best predictive model. The common variable selection methods are mainly the stepwise regression and all possibility regression method. The stepwise regression can not found the best model usually when establishing the predictive model[1], especially when dealing with an overfitting data. The all possibility regression needs the great calculating quantity and is time-consuming. If the quantity of independent variables is n, the quantities of all possible models are 2n. So if n>10 the calculation can not be done by an ordinary computer.

    Determination of Mercury in some TCMs (Traditional Chinese Medicines) by ICP-MS and Sepeciation of Mercury Species Using Ion-Exchange Chromatography
    WU Xi-Hong, GONG Hai-Fang, CHEN Fa-Rong, ZHUANG Zhi-Xia, SUN Da-Hai, WANG Xiao-Ru, Frank S. C. LEE
    2000, 21(S1):  36-36. 
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    Cinnabar, composed mainly of HgS,is often used in Traditional Chinese Medicines as part of the active ingredients in formulated drugs to treat diseases such as epilepsy,sore throat. To gain understanding on the clinical efficacy, safety and toxicity of these TCMs, information regarding not only the total concentrations of the heavy metals, but also their different chemical species is necessary. Therefore, the development of sample treatment and analytical techniques for the accurate determination and speciation of heavy metals in TCM products are of critical importance. The dual objectives of this work are to:(1) develop a leaching procedure using simulated body fluids for bioavailability and toxicity studies, and (2) investigate the possibility of Cinnabar derived mercury to bind with other constitutes in Tian Wan Bu Xin Wan using a sequential extraction scheme.

    Fluorescence Quenching Sensor Film for Inorganic Phosphate
    ZHONG Zhen-Ming, CHEN Xi, LI Wei, ZHUANG Zhi-Xia, WANG Xiao-Ru
    2000, 21(S1):  37-37. 
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    Phosphorus, in the form of organic or inorganic phosphate, is an important and widely distributed element in nature. Excessive phosphorus causes water to entrophicate. Most of the commonly used methods for the determination of inorganic phosphate in water are based on spectrophotometric measurement of the phosphomolybdate or phosphomolyb-dovanadate, Among the fluorescence quenching methods using metal chelates, the aluminium-morin system was found to be the most suitable for determining phosphate[1].

    Alkali Metal Adduct Ions Technique in Combination with Fast Atom Bombardment/Tandem Mass Spectrometry in the Analysis of Oligoglycoside Mixtures
    PAN Yuan-Jiang, SUN Cui-Rong, CHEN Yao-Zu
    2000, 21(S1):  38-38. 
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    The combination of fast atom bombardment (FAB) with tandem mass spectrometry (MS/MS) has been shown to be a powerful tool for the characterization of oligoglycosides. Recent investigations of alkali metal attachment to oligoglycosides via ionization technique of Fast atom bombardment showed more possibilities for this propose[1,2].

    Assembly of Multilayered Films on Core Substrate:Preparation and Characterization
    YANG Wen-Jun, HUANG Qun-Jian, LI Xiao-Yuan, YU Nai-Teng, CARUSO, Frank
    2000, 21(S1):  39-39. 
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    Certain colloidal metals such as.silver (Ag), gold (Au) and copper, (Cu), when properly or assembled, display remarkable enhancement effect to the Raman scattering cross section of adsorbed molecules. This surface-enhanced Raman scattering (SERS) phenomenon has found wide applications in the study of interfacial chemical processes and is a potentially non-invasive technique in molecule-specific analysis. However, the SERS activity of metal colloids depends sensitively on both the synthetic method and the aggregation and assembly procedure, making it difficult to develop SERS into a reliable and quantitative analytical technique. To solve this problem, one needs to develop a substrate with a well-defined adsorption area and SERS activity. One approach to achieve this goal is to assemble a monolayer of uniform colloidal metals onto a well-defined secondary substrate. Here we report our effort in assembling monolayers of uniform Au nanoparticles on the well-defined optical-inactive microparticles in a layer-by-layer (LbL) manner and the use of such assembly as SERS-active substrate.

    Development and Application of Chemometric Methods in Near Infrared Spectral Analysis
    YUAN Hong-Fu, LU Wan-Zhen
    2000, 21(S1):  40-41. 
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    In recent 10 years, like other disciplines influenced by the fast development of PC technique, chemometrics has been used in many analytical methods, especially in instrumental analysis. This article describes applications and comparison of multivariate linear regression (MLR), principal component analysis (PCA), principal component regression (PCR), partial least square (PLS), neural network (ANN), fuzzy and model recognition. A better calibration method can be a great help to improve the efficiency of the routine analytical work.

    A Validated Approach to Discovering Implication Knowledge from Empirical Data with Applications in Chemometrics
    LIU Ji-Ming, Frank S. C. LEE, WANG Xiao-Ru, YING Hai
    2000, 21(S1):  42-42. 
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    Implication knowledge is useful for drawing conclusions or confirming hypotheses based on some observed data. The challenge here is where/how to derive such knowledge. Traditional knowledge acquisition methodologies or tools have limited power in that they rely on human knowledge engineers' judgements and are applicable only under controlled situations. It would be desirable as well as imperative if we can demonstrate any automatic means of mining such implication knowledge directly from empirical data-this is because in practical applications,data samples are usually available and most importantly the automatically induced implications are less subjective and mathematically sound. As a response to this challenge, our work has developed and validated a new method of automatically discovering implication knowledge by statistically inducing the implication relationships among the data attributes in empirically-obtained sample data.

    A Method to Uncouple Meso- and DI-Isomers of Diethyl-2,3-Dicyano-2,3-Diphenylsuccinate-Recrystallization in Mixed Solvent and Theoretical Analysis
    HUANG Hong-Jun, YAN Jun, ZHANG Wen-Yu, REN Feng-Zhi, WANG Xing-Fang
    2000, 21(S1):  43-43. 
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    Diethyl-2,3-Dicyano-2,3-Diphenylsuccinate is a novel carbon-carbon bond macro-molecular initiator. The meso- and dl-isomers can be obtained as mixture while preparing the initiator by the Cu2+-catalyzed oxidative coupling of α-cyano-phenthylacetate. However, their uncoupling is hard The authors have finally found recrystallization in mixed solvent (CCl4:CH3OH=9:1) is an effective method to uncouple the isomers. By this method, we obtained pure meso-(Ⅰ) and dl-(Ⅱ) confounds. HNMR spectra identified their purity and structure.

    Study on Quantitative Structure Property Relationship by Gray Model
    SUN Zhao-Lin, LENG Jing, ZHANG Zhi-Gang, ZHANG Xiao-Tong
    2000, 21(S1):  44-44. 
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    One of the challenges in quantitative structure-property relationship (QSPR) investigations is to predict the properties of a substance when the structure is known. Poct,partition coefficient between octanol and water, is of great importance in quantitative structure-activity relationship (QSAR) studies. The logarithm of the capacity factor (logk') obtained from RPLC has been used as an alternative method of the conventional shaking-flask method for predicting the logarithm of Poct (logP). This approach has received much attention, but some problems have been reported. In this study, a type of new gray model has been used to model and predict logP as function of different structure parameters.

    Determination of Flavonoids in Saururus Chinensis(Lour.)Baill by High-Performance Liquid Chromatography
    XU Xue-Qin, YE Hong-Zhi, CHEN Guo-Nan
    2000, 21(S1):  45-45. 
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    Flavonoids (including quercetin, rutin, hyperin, isoquercitrin) are major components of Saururus Chinensis(Lour.) Baill, Their determination by differential-pulse polarography, coulometry and colorimetry has been investigated by several workers[1-2]. In this essay, a reversed-phase HPLC method was developed to determine quercetin and rutin in Saururus Chinensis(Lour.) Baill.

    Study on the Electrochemical Behavior of 10,10'-Dimethyl-3,3'-disulfonyl -biacridinium Dinitrate and Its Application
    XU Xue-Qin, ZHUAG Hui-Sheng, CHEN Guo-Nan
    2000, 21(S1):  46-46. 
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    10,10'-dimethyl-3,3'-disulfonyl-biacridinium dinitrate(DMDSBA) synthesized in our laboratory is a derivative of lucigenin with two sulfonic group Althpugh the electrochemical reduction of lucigenin at various types of electrodes has been studied[1-4], the electrochemical behavior of its derivatives Has not been reportedl In this essays the electrochemistry of DMDSBA is investigated and its application is also discussed.

    Studies on the Chemical Constituents of the Leaves of Callicarpa Bodinieri Levl.
    REN Feng-Zhi, QU Hui-Hua, LUAN Xin-Hui, ZHAO Yi-Min
    2000, 21(S1):  47-47. 
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    The genus Callicarpa (Verbenaceae) comprises nearly 30 species, occuring mostly in East Asia, Malaysia and North Australia. Callicarpa bodinieri Levl, grows throughout North China[1]. The leaves of C.bodinieri are used as folk analgesic. We studied the chemical constituents to look for new analgesic principles.

    Electrochemical Hydride Generation:A Novel Sample Introduction Method for the Non-dispersive Atomic Fluorescence Spectrometry
    LI Shu-Ping, GUO Xu-Ming, HUANG Ben-Li, LI Bin, HU Rong-Zong
    2000, 21(S1):  48-48. 
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    Production of volatile covalent hydrides of environmentally important elements (As、Se、Bi、Ge、Sn、Sb and Pb) by reaction with sodium (potassium) tetrahydroborate (NaBH4) in acidic media for determination by atomic absorption has been widely used in routine analysis. However, this technique has several disadvantages. NaBH4 is a potential source of contamination, its aqueous solution is unstable. As an alternative to chemical hydride generation, hydride generation by electrochemical reduction (EcHG) has been reported in recent years by many authors[1-3]. Compared with NaBH4 hydride generation system, the EcHG with subsequent detection by atomic absorption spectrometry offers the high sensitivity, low detection limits, and the absence of interference from the transition metals. However, the hydrogen produced by EcHG reduced greatly, this led to the interference caused by hydride forming elements was serious due to the lack of free hydrogen (H·) radical in the quartz tube during the atomization. EcHG coupled with atomic fluorescence spectrometry system uses Ar-H2 mini-flame as an atomizer, in which the gaseous phase interference can be expected eliminated. In addition, non-dispersive atomic fluorescence spectrometry (NDAFS) system with a quite single structure, is a very sensitive and feasible method for the measurement of elements that form volatile hydrides. By combining with electrochemical hydride generation as a sample introduction technique, it is possible to develop a potential interface for chromatography or capillary electrophoresis in speciation analysis.

    A Fluorescence Sensitive Membrane for pH Based on Rhodamine B Immobilized on a Plastized PVC
    XIE Zeng-Hong, NIE Qiu-Yan, GUO Liang-Qia, CHEN Guo-Nan, CHEN Xi, LI Wei, WANG Xiao-Ru
    2000, 21(S1):  49-49. 
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    Many fiber-optic pH sensors have been largely reported since 1980s. Most of them were usually obtained by immobilized indicators on ion exchangers, polyacrylamide, cellulose membranes, sol-gel[1] et al. PVC membrane was largely applied in pH modify electrode, but up to now applying PVC membrane in optical fiber pH sensor was rarely reported.

    Simultaneous Determination of Pseudoephedrine, Paracetamol and Dextromethorphan by Capillary Electrophoresis with Diode-array Detection
    ZHANG Lan, CHEN Guo-Nan, FANG Yu-Zhi
    2000, 21(S1):  50-50. 
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    Some analytical methods, such as titration[1], TLC[2], GLC[3], HPLC[4] and spectrophotometry[5] for determination of single ingredient of pseudoephedrine hydrochloride (PSED), paracetamol (PRCT) and dextromethorphan hydrochloride (DEMP) in some mixture have been reported. However, there were no papers for determination of PSED, PRCT and DEMP simultaneously in one tablet. The methods mentioned above needed complex procedures or required some solvents, which might result from pollution, and both of them consumed long time to complete the separation. Therefore it is necessary to develop a new analytical method which could save time and cost.

    Separation and Determination of the Active Ingredients in Tablets Composite Triamterene by Capillary Electrophoresis with Amperometric Detection
    ZHANG Lan, PAN Ya-Ling, CHEN Guo-Nan, FANG Yu-Zhi
    2000, 21(S1):  51-51. 
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    Hydrochlorothiazide (HCTZ) is one of the diuretics. When it incorporated with triamterene (TATR), better therapeutic effect would be obtained[1].A simple, rapid method for separation and determination of TATR and HCTZ in composite tablets by capillary electrophoresis (CE) with amperometric detection (AD) was demonstrated in this paper.

    Study of the Active Ingredients in Common Cold Medicines by Capillary Zone Electrophoresis with Amperometric Detection
    ZHANG Lan, HE Yu, CHEN Guo-Nan, FANG Yu-Zhi
    2000, 21(S1):  52-52. 
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    The patients of common cold and influenza usually have some uncomfortable symptoms, such as stuffy nose, runny nose, sneezing, coughing, headache and fever. Recently the new cold medicine often contains several components, and its comprehensive effect can decrease symptoms of cold. Pseudoephedrine hydrochloride (SDP), chlorphenamine maleas (CLM), caffeine (CAF) and paracetamol (PRC) are usually existed as combination in cold medicines:SDP as a vasoconstrictor for reducing nasal congestion, CLM as a cough suppressant, and CAF and PRC as an analgesia and antipyresis. Due to matrix effects and complex ingredients, it is very difficult to detect these four components mixture simultaneously. Capillary zone electrophoresis-amperometric detection (CZE-AD) offers a rapid, simple, sensitive, low cost and high separation method for determination of above mixture.

    A Pair of New Chiral Reagents for Determining the Configuration of Some Organic Compounds by Reaction Mass Spectrometry
    WU Yi-Nan, PAN Yuan-Jiang, CHEN Yao-Zu
    2000, 21(S1):  53-53. 
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    In our previous work, Reaction Mass Spectrometry (RMS) has been applied to determine the configuration of some enantiomers[1-4], by using some chiral organic compounds such as R, S-α-hydroxyphenylacetic acid, R, S-α-methoxyphenylacetic acid and R, S-phenylbutyric anhydride etc. as reaction reagents. As a continuation of this investigation, a pair of new asymmetric compounds (R)- and (S)-1, 1'-binaphthyl-2, 2'-diyl-methylphosphate (R, S-BNP ester) are used as stereoselective reagents. By comparison of the relative abundances of characteristic ions formed by reaction between the sample and the two enantiomers of the reagent, the configuration of the samples can be determined at the micromole level within a few minutes by reaction mass spectrometry.

    Crystal Forming Competition Between Some Pyridinium Trifluoroacetic Acetates
    JIN Zhi-Min, PAN Yuan-Jiang, YUE Lin-Hai
    2000, 21(S1):  54-54. 
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    It is difficult to separate 4-methylpyridine (4-MP), 3-methylpyridine (3-MP) and 2,6-dimethylpyridine (DMP) which exist concurrently in tar oil distillation, because of their similar boiling points (4-MP, 145℃; 3-MP, 144℃;DMP, 144℃). Efforts have been made to separate 3-MP from the mixture of 4-MP and 3-MP by forming inclusion complex of 3-MP with hexadiyn, and with benzopinacol[1]. And, trifluoroacetic acid (TFA) has been used to separate 4-MP from the mixture of methylpyridines by reactive distillation[2]. Recently, TFA is used to separate 4-MP from the mixture by preferential co-crystallization. It is reported hereafter the crystal formation competition between some pyridinium trifluoroacetic acetates.

    Structure Determination and Detailed of 1H and 13C NMR Spectra Assignments of Villosumcoronarine-a New Diterpene from Hedychium Villosum Wall (Zingiberaceae)
    SUN Cui-Rong, XIAO Peng, PAN Yuan-Jiang, CHEN Yao-Zu
    2000, 21(S1):  55-55. 
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    Villosumcoronarin, a new diterpene isolated from the dried leaves of Hedychium villosum Wall (Zingiberaceae), yellow crystal (Et2O), m.pl08.4-108.8℃, has the molecular formula C20H28O2 derived from ESIMS (m/z 301, positive and m/z 299, negative), EIMS (m/z 300) and 13CNMR (DEPT 90 and DEPT135) spectral data., whose structure was elucidated as labda-8 (17), ll, 13-triene-15-oic-16-lactone (Figure 1) by the NMR spectral studies. The detailed NMR resonance assignments of these compound were achieved by using the 2D-NMR,1H-1H COSY, HMQC, HMBC and NOESY tests and comparing the spectroscopic data with yunnancoronarin B[1,2] (figure 2).

    Development of Novel Substrates for Surface-enhanced Raman and Surface-enhanced Hyper Raman Spectroscopy
    HUANG Qun-Jian, LI Xiao-Yuan, YU Nai-Teng
    2000, 21(S1):  56-56. 
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    Since its discovery two decades ago, surface-enhanced Raman scattering (SERS) has been explored extensively as a useful technique in the study of molecular behaviors at interfaces and in chemical and biochemical analysis. At solid-liquid interface, SERS has been practiced mainly in aqueous solution on either aggregated metal colloids or roughened metal electrodes. However, both aggregated metal colloids and roughened electrodes have their own problems as SERS substrates. One of the intriguing questions in exploring SERS application in chemistry is that can SERS-activity be gained and regulated from the dispersed metal nanoparticles immobilized on a SERS-inactive smooth electrode surface. The very essence of this question is to explore the effect on SERS-activity when the main features of two conventional SERS-surfaces, namely metal colloids and electrode, are combined. Same question can also be asked for the nonlinear three-photon surface-enhanced hyper Raman scattering (SEHRS).

    Theoretical Studies on the Potential Energy Surface and Rovibrational States of OCS
    XIE Dai-Qian, LU Yu-Hui, YAN Guo-Sen
    2000, 21(S1):  57-57. 
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    Carbonyl sulfide (OCS) is the most abundant sulfur-containing species in the troposphere of the earth and has been observed in several molecular cloud sources in the interstellar medium by radio astronomy. Recently the potential energy surface (PES) and the rovibrational spectra of OCS have been studied extensively by experimental and theoretical techniques.

    Electrochemical Reduction Characterizations of Aromatic Nitro-Compounds
    MA Chun-An, ZHANG Wen-Kui, HUANG Hui, GAN Yong-Ping, LI Mei-Chao
    2000, 21(S1):  58-58. 
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    In this paper, the electrochemical reduction characterizations of the aromatic nitro-compounds including nitrobenzene, α-nitronaphtahlene and l,5-dinitroanthraquinone in the sulfuric acid solution were investigated and the reaction mechanism was proposed as well. The electrochemical measurements such as cyclic voltammetry, quasi-steady-state polarization, fast linear potential sweep and chronoamperometry were carried out by using EG&G 273A electrochemical measurement system. The results showed that three compounds could be reduced electrochemically to the corresponding aminophenol confounds under the suitable reaction conditions on Cu-Hg cathode. The reduction peak potential was all in the range of -0.4 to -0.6 V (vs. SCE) for the above confounds. The corresponding specific surface activity energy tested was 21.5, 16.4 and 21.2 kJ/mol respectively, means the better electrochemical reduction activity on Cu-Hg electrode. Further investigation on the reaction mechanism disclosed that α-nitronaphtahiene and 1,5-dinitroanthraquinone have the similar reaction mechanism to that of nitrobenzene to para-aminophenol, i.e.,Bamberger rearrangement courses. With the increasing of the number of benzene number, the temperature and the concentration of needed for the electrochemical reduction increased correspondingly, i.e.,90℃ for nitrobenzene, 110℃ for α-nitronaphtahlene and 140℃ for l,5-dinitroanthraquinone respectively. The reaction rates are proportional to the concentration of the reactants the corresponding conditions.

    EPR Properties of Mixed Ligand Complex of Cu(Ⅱ)-BpheO-bipy
    WANG Guo-Ping, LEI Qun-Fang
    2000, 21(S1):  59-59. 
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    A new copper(Ⅱ) complex with N-Benzoylphenylalanine and 2, 2'-bipy has been synthesized according to our previous work[1].Elemental analysis of the complex indicates that its composition is[Cu(BpheO)2(bipy)]·H2O. EPR spectra of the complex in polycrystalline powder and in two organic solvents(CHCl3 and Py) at two different temperatures (room temperature and 173K) were investigated. The bonding characterization of the complex in two solvents was discussed.

    A New Topologica Index X & Its Application in QSRR
    GUO Wei-Qiang, LU Yang, ZHENG Xiao-Ming
    2000, 21(S1):  60-60. 
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    For a long time, a lot of research studies have already been done to predict the chromatographic retention index values, among them, the methodology called quantitative structure-retention relationship (QSRR) is one of the widespread way permit generation of useful equations or models for the prediction of retention index for molecules. QSRR investigations in the past two decades have made significant progress and numerous papers on this topic have been published.

    The Study of Diagnostic Method of Diabetes by Thermal Desorption-Gas Chromatography
    GUO Wei-Qiang, CHEN Miao-Ying, NI Jun, HE Jie
    2000, 21(S1):  61-61. 
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    With the development of Chinese economics, the morbidity of diabetes, as one kind of metabolic disease, is more than before. Because of its multiple causalities and complex disorder, it is not very easy to diagnose the diabetes. The patients will suffer for the routine detection method of blood sugar, an invasive diagnosis technique. In fact, as one of the many diagnostic methods, to "smell" out diseases from the odors in man's breath is being newly developed in the biomedical area, which is applied in such diseases as:gastrointestinal problems, sinus problems, infections, diabetes, liver problems infected wounds. Some researchers[1,2,3] use electronic nose to detect the concentration of the "odors" and to diagnose these diseases. The detection of acetone in man's breath is convenient to be used to predict ketoacidosis and monitor the process of diabetes.

    Study on the Dye-Doped Funcionalized Silica Nanoparticles for The Recognition of SmIgG+B Lymphocytes
    WANG Ke-Min, HE Xiao-Xiao, XIAO Dan, LI Jun, YANG Xiao-Hai, LI Qi
    2000, 21(S1):  62-62. 
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    The development of sensitive non-isotopic detection sys tem for biological and medicinal applications, such as single cell analyse, DNA sequence, clinical diagnose etc., has driven nanomaterials more towards cell biology and ultrasensitive immunoassay[1]. Semiconductor nanoparticles have been used for coupling biomolecules but suffer from some disadvantages including poor solubility in water, blinking properties or low quantum yields[1,3,4]. In this paper, we developed a novel dye-doped functionalized silica nanoparticles and used for detection of SmIgG+ B lymphocytes.

    Determination of Hexavalent Chromium in Waste Water Using A Synchronous Fluorescence and Absorbance Dynamic Liquid Drop Sensor
    WANG Ke-Ming, XIAO Dan, XIAO Wen-Xing, YANG Xiao-Hai, XU Ru-Jun
    2000, 21(S1):  63-63. 
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    Hexavalent chromium is known to damage exposed skin, irritate mucous membranes, produce pulmonary sensitivity, create dental erosion, cause loss of weight, induce renal damage, and target the respiratory tract and skin 1 U.S. EPA has designated Cr(VI) as a carcinogenic, substance that may cause a range of diseased from dermatitis to lung and kidney cancer, Considerable interest has been arose for Cr(VI) in waste water based on a synchronous fluorexcence and absorbance renewable drop sensor. P. K. Dasgupta et al4 has intensively investigated liquid drops and films as analytical devices, The unique features of a liquid drip can be characterized in its reproducibility, renewability, defined volume and lack of containment walls, These features.individually or in combination, led to unique systems for certain applications, e.g. windowless optical cells, micro liquid handling vessels, renewable gas sampler, and simple interfaces.

    Study and Application of Ultrasound in Electroanalytical Chemistry
    LIU Bin, SUN Xiang-Ying, XU Jin-Rui
    2000, 21(S1):  64-64. 
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    Recently there are some studies in the literature where sonochemistry is combined with electrochemistry[1,2],but the possible mechanisms only have been briefly described, the applications are seldom reported. Ultrasound at or near the electrode can accelerate the mass transport to and from it, activate its surface resulting from continuous cleaning and cavitation, so Chance the sensitivity[2-3]. In this paper we introduce the possible mechanisms and its applications by examining the anodic stripping voltammetric determination of copper in the presence of ultrasound.

    Preparation of Doped Tungstophate PolypyrroleFilm Modified Electrode and Its Use in Measuring Nitrite in Sour Rain
    SUN Xiang-Ying, LIU Bin, XU Jin-Rui
    2000, 21(S1):  65-65. 
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    Nitrite, one of the pollutants widely found in atmosphere and sour rain, is an essential precursor in the formation of nitroamine, many of which have been shown to be potent carcinogens. Therefore, the detection of nitrite has received continued attention over the past ten years[1,2], spectrophotometry and ion-chromatography are mainly used Direct reduction of nitrite requires a very high overpotential at most of the conventional electrodes, but many transition-metal substituted heteropolytungstates have shown their electrocatalytic activities[3] and can be applied as an electrochemical detector to monitor nitrite in sour rain.

    Characterize the Alkaline Lipase by CIEF, HPLC and MS
    SONG Hao-Wei, YUE Gui-Hua, WU Min-Chen, YANG Peng-Yang, XU Yun-Min, LIU Wei-Ping
    2000, 21(S1):  66-66. 
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    Lipase is one kind of enzyme, which is useful in the home laundry in recent years. The study of lipase is attracting more and more attentions. And the gene engineering has produced many different kinds of lipase. Some heterogeneity of the alkaline lipase is extracted from penicillin cyclopium PG37 in the first time. Results of the database searching with the N-terminal sequence demonstrate that those proteins are new and have little homogenous with order lipases. All properties of this lipase, which has been studied, suggest that the enzyme could be used as a home laundry product ingredient. Thus, it is very important to characterize the protein and to study the reaction with the antibody[1].

    Determination of Pb In Mn3O4 by GFFS with Direct Suspension Injection Technology
    YAO Zu-Fen, LIU Jun, YAO Jun
    2000, 21(S1):  67-67. 
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    Due to the matrix modify technology and direct suspension injection was adapted in determination of trace Pb in products Mn3O4, Troublesome chemical process of samples was abolished, the results show that it possesses convenience, rapidity and accuracy.

    Determination of Polysaccharide in Ginkgobilogal by Ultrasonic Fragmentation Pretreatment with HPLC Analysis
    DENG Yong-Zhi, YUAN Dong-Xing, LIN Qing-Mei, LI Quan-Long
    2000, 21(S1):  68-68. 
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    Ginkgobilogal is one of the most antiquated plants in the world, and thus considered as a gymnosperm living fossil. According to BEN CAO GANG MU, Ginkgoblogal can smooth asthma, relieve enuresis and leucorhea. The pharmacological study in the last two decades shows that the flavone and latone in Ginkgobilogal leaves are able to dilate coronary artery vein, increase cerebrovascular flux, ameliorate alimentation of brain and strengthen antibacterial ability. So far the studies about live-effectual components in Ginkgobilogal and its extracted materials (GBE) almost all focus only on flavone and latone. In fact there are more tiian 200 components in Ginkgobilogal and GBE. However, quite few effectual components have been identified In this study bio-effectual polysaccharide is extracted from Ginkgobilogal leaves and GBE with the method of ultrasonic fragmentation, and then analyzed with HPLC.

    Simultaneously Determination of Aldoses and Alduronic Acids in Plant Heteropolysaccharide by Gas Chroraatograhpy
    LI Zhi-Xiao, MEN Yan-Fa, CHEN Yao-Zu
    2000, 21(S1):  69-69. 
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    The analysis of hydrolysis mixture derived from heteropolysaccharides is often complicated by the presence of alduronic acids in addition to the aldioses normally resent. Aldoses can easily be determination by gas chromatography (GC) as the alditol acetates[1], aldononitrile acetates[2] or trimethylsilyl (TMS)[3] derivatives. Alduromic acids are most often analyzed spectrophotometrically with carbazole or m-hydroxydiphenyl[4] etc. These commonly used methods are non-specific in that they do not identify which acid is being analyzed.

    Sensitive Liquid Chromatographic Determination of Neurotoxin β-ODAP and Non-protein Amino Acids in Lathyrus sativus by Precolumn Derivatization with Dansyl Chloride
    WANG Fei, XING Gen-Shen, CHEN Xiong, LI Zhi-Xiao
    2000, 21(S1):  70-70. 
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    Lathyrus sativus (L. sativus) is a highly drought resistant and protein-rich leguminous crop cultivated in Africa and Asia, where it is a major protein source for people in the lowest income groups. However, excessive ingestion of this pulse can lead to irreversible paralysis of the legs-a disease known as neurolathyrism or lathyrism. The causative agent was reported to be the nonprotein amino acid, 3-N-L-oxalyl-2,3-diaminopropionic acid (β-ODAP)[1]. The α-isomer of ODAP has been shown to be nontoxic. L. sativus (shan li dou in China) shows good adaptation to the low rainfall conditions of northwestern China. Our group was exploring the breeding low or zero toxin varieties of L. sativus as grain crops for human consumption and as protein-rich feed for animals. Thus, it is necessary to develop a method to determine the toxin and other amino acids. Derivatization by 5-dimethylaminonaphthalene-l-sulfonyl chloride (DnsCl) as derivatization reagent was used for analysis of amino acids by Negro et al.[3] Sanz[4]. We have developed a HPLC method that can simultaneously determination the a- and|3-ODAP and other amino acids in L. sativus by dansylation. The method provides a simple accurate alternative to existing methods for plant screening purpose.

    Analysis of Organophosphorus Pesticides in Water with Enzyme Membrane Extraction-Gas Chromatography
    XU Peng-Xiang, YUAN Dong-Xing, CHEN Meng, ZHONG Shu-Ming
    2000, 21(S1):  71-71. 
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    The pollution of organophosphorus pesticides in water, especially in drinking water source, is a vital threat to life. Therefore, great concern is being focused on the effects of pesticide residues on public health and wildlife. The detection of trace organophosphorus pesticide residues in water is a very important task. In the recent years, the immunoassay technique has been utilized in the determination of trace organophosphorus pesticide residues in various environmental samples.

    Catalase Measurement in Marine Biological Samples by Fluorometric Assay
    MAO Yu-Xia, GUO Xiang-Qun, CHEN Rong, ZHENG Wei-Yun
    2000, 21(S1):  72-72. 
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    Condenced aromatics in the environment are harmful to the organisms for its carcinogenesis. When it is metabolized in organism, several kinds of radicals and active oxygen intermediates such as superoxide radical anion (O2-) and hydrogen peroxide would produce. These active oxygen intermediates may cause DNA damage. Catalase (CAT), a major endogenous antioxidant, presents in all aerobes and has a crucial function in protecting living organisms against the unrestrained reactivity of H2O2. When the amount of H2O2 generated in the body increase due to the outside factors, the activity of the CAT will be induced to rise significantly. Thus the activity of CAT, as a biomarker, may reflect die exist of condensed aromatics in the environment. Now there are many methods to detect CAT, such as spectrophotometric methods, titration,electrochemical process, volumetric analysis, but they are not sensitive enough for direct detection of CAT in marine biological samples.

    Study on the Nitroxide-linked Naphthalene as a Probe for Hydroxyl Radicals
    YANG Xiao-Feng, GUO Xiang-Qun, LIU Jian-Li, MAO Yu-Xia, ZHAO Yi-Bing
    2000, 21(S1):  73-73. 
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    Reactive oxygen species (ROS),such as superoxide radical (O2-)and hydroxyl radical (OH), are thought to be involved in the action of many toxins and several human diseases. Among the various radicals,the hydroxyl radical is presumed to play a central role due to its strong activity. Several methods have been developed to detect hydroxyl radicals. Among them, one of the most commonly used is ESR method. Because of a high-cost instrument, this method is not suitable for routine analysis. Another method is aromatic hydroxylation. Though this method is highly sensitive, the multiple hydroxylation products make the quantitative detection of hydroxyl radical complex.

    Study of the Electrochemiluminescence Based on the Reaction of p-Hydroxyphenylpyruvic Acid with Tris(2,2'-bipyridine)ruthenium(Ⅱ)
    CHI Yu-Wu, DUAN Jian-Ping, CHEN Guo-Nan
    2000, 21(S1):  74-74. 
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    p-hydroxyphenylpyruvic acid (pHPP) is an important intermediate in the metabolism of tyrosine. Under normal circumstances pHPF is readily converted to 2,5-dihydroxyphenylacetic acid by p-hydroxy-phenylpyruvate oxidase and the levels of pHPP encountered in blood and urine are extremely low. However, in a few individuals suffering from a congenital metabolic defect known as tyrosinemia, the oxidase is not available which leads to dramatic elevation of pHPP levels in blood and urine[1]. Therefore, a selective and sensitive method for measuring pHPT is very useful for the diagnosis and treatment of such disease. In this paper the electrochemiluminescence(ECL) based on the reaction of pHPP with tris(2,2'-bipyridine)ruthenium(Ⅱ)[Ru(bpy)32+] in a flow injection system has been studied and a sensitive ECL method has been developed to detect pHPP in aqueous solution.

    Solvent Sublation for Surface-Active Substances from Aqueous Solution, Comparison with Solvent-Extraction
    LU Yu-Juan, ZHU Xi-Hai
    2000, 21(S1):  75-75. 
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    The solvent sublation technique, a non-foaming technique, is originated by Sebba[1] as an option for ion flotation, in which the surface active solute in water is adsorbed on the surface of ascending bubbles and then collected in an immiciable solvent As we know that there are a number of features that make the technique more advantageous than that of the solvent extraction:the possibility of easy handling of large volumes of aqueous sample; the equilibrium state established not in the bulk of system but only at the aqueous-organic interface and the recovery of trace elements eventually reaching 100%; no emulsion formation[2-3]. Furthermore, the effluent water from a sublation column doesn't require further treatment to remove residual solvent. The handles are single and expenses are cheap, so the solvent sublation has the potential in the environmental treatment and the separation and preconcentration process[4-6]. The aim of this paper is to investigate the experimental possibilities of the solvent sublation and its intercomparison with conventional liquid-liquid extraction, in order to get more information on widely applications in the near future.

    Removal of Organic-Dye (Bromophenol Blue) by Solvent Sublation
    LU Yu-Juan, ZHU Xi-Hai
    2000, 21(S1):  76-76. 
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    The solvent sublation technique, one of adsorption bubble separation techniques, is initially proposed by Sebba[1] as an option for ion flotation, in which the material adsorbed on the surface of ascending bubbles and then collected by a solvent in the column upper zone. The technique has advantage over ion flotation or solvent extraction:the possibility of easy handling of large volumes of aqueous samples; not limited by the equilibrium constant; the recovery of trace elements can eventually reach 100%; no emulsions formed; independent on the organic to aqueous phase volume ratio. So it has attracted many attentions in the removing trace levels of nonvolatile and volatile organic compounds from wastewater and the recovery of many metals[2,3]. But the studies on the mechanism of the process are very few[4],which is very important to the better application. So, in the paper, we investigated on the kinetics and thermodynamics of solvent sublation of Bromophenol blue-hexadecyl-pyridiumchlorid and compared the efficiencies of solvent sublation with conventional separation methods.

    Determination of Polynuclear Aromatic Hydrocarbons in Sediment Porewater by SPMD
    ZHU Ya-Xian, ZHANG Jie, ZHANG Yong
    2000, 21(S1):  77-77. 
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    The mobility and bioavailability of organic pollutants associated with sediment depend on the concentrations of these compounds in the porewater[1]. To assessment and impact the effect of these kinds of organic pollutants on the benthic ecosystem, and the effect of these contaminates were released as a second pollution source, it is in important to know the accurate concentrations of these organic pollutants in sediment porewater[2]. However, the available methods are not effective[1]. In 1990,the Semi-permeable Membrane Devices (SPMD)[3] have being used to passively sample bioavailable aqueous organic pollutants, such as PCBs,OCPs and other organic pollutants.

    Determination of 1-Hydroxy Pyrene in Fish Bile by Synchronous Fluorescence Spectrometry
    ZHANG Yong, WANG Shu-Hong, FENG Ren, ZHU Ya-Xian, ZHENG Feng-Lan
    2000, 21(S1):  78-78. 
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    Environmental pollution with polynuclear aromatic hydrocarbons (PAHs) has being concerned. PAHs are mainly bound to sediment particles in the aquatic environment, but may still be biologically available to marine organisms[1]. So PAHs could be harmful to human beings by food chain transportation and accumulation. Routine monitoring of PAHs levels in the aquatic environment usually involves the determination of parent PAHs in sediment samples. Additional information on the actual uptake of these compounds by aquatic organisms can be obtained by a biomonitoring approach. However, the biotransformation rates of PAHs in fish are relatively high, and the analysis of parent PAHs in liver and muscle tissue is difficulty. Therefore, the biomonitoring of PAHs uptake should be concerned on the determination of PAHs metabolites in excreta. In this study, a simple, fast and easy operation synchronous fluorimetry has been established for this purpose.

    Determination of Epicholestanol and Coprostanol by Gas Chromatography-Mass Spectrometry
    ZHANG Hong, LIANG Xin-Le, HAN Jian-Zhong, PAN Yuan-Jiang
    2000, 21(S1):  79-79. 
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    Coprostanol and epicholestanol are tow kinds of steroids, and have the same constitutions. Coprostanol, 5β-cholestane-3β-ol, it is a sterol formed exclusively in the gut of man and higher mammals, has been recognized as a good indicator of pollution of water resources by sewage discharge. In order to complete resolution of chromatography peak, coprostanol need to be converted into its corresponding trimethylsilyl derivative. Epicholestanol, 5α-cholestane-3α-ol, was used in oral compositions for periodonted disease control.

    Quantitation Free Fatty Acid in Perilla Seed Oil by Capillary Gas Chromatography Combined with Column Chromatography
    ZHANG Hong, ZENG Su, PAN Yuan-Jiang, LI Shi-Min
    2000, 21(S1):  80-80. 
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    Perilla frutescens is a member of the Lamiaceae family. It is he first group material which are identified as both medicine and food by Health Ministry of China. Recently the high content of α-linolenic in the seed of Perilla had aroused many scientists attention. Perilla seed oil is plant oil sources of the curative and edible value, which contains high content of α-linolenic(more than 50%). The α-linolenic which is a polyunsaturated fatty acid, however, is very easy to be degradation. The product of rancidity and oxidation changes the quality of oil and some degradation products are harmful to human health.

    Study on the Supramolecular Inclusion Complex of β-Cyclodextrin with Retinoic Acid
    ZHANG Yan-Ling, LIU Wei-Sheng, LIAO Kai-Jun, MA Xue-Yi
    2000, 21(S1):  81-81. 
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    The importance of Vitamin A for human health has been stressed in resent studies, meanwhile its derivative so-called retinoic acid (RA) has been widely used as pharmaceutical to treat several types of skin disease and cancer. However the application of retinioc acid is restrained for its poor water solubility, unstability and side affect on the human body. A large number of studies in pharmaceutical field showed that β-CD could inqjrove the water solubility of poorly soluble of drugs, reduce the toxicity and increase the dissolution rate, In the present work, the inclusion compound of retinoic acid with β-cyclodextrin was prepared by coprecipitating method, the structure of resulting product was studied by elemental analysis, differental scanning caloriemetry(DSC) analysis, FT-IR spectroscopy and X-ray diffractometry, and the formed supramolecule self-assembles in aqueous solution according to molar ratio 2:1 of host-guest.

    Structural Analysis of ZnⅡ and CdⅡ Complexes with Bis(1,1,3,3-tetramethylbutyl)dithiophosphinic Acid by FT-IR and 1H NMR
    YANG Li-Min, WANG Qiu-Quan, HUANG Ben-Li
    2000, 21(S1):  82-82. 
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    Bis(l,l,3,3-tetramethylbutyl)phosphinic acid (HMBP) as an extractant is of selectivity to many kinds of metal ions.1Bis(1,1,3,3-tetramethylbu1yl)dithiophosphinic acid (HDTP), which has a similar structure to HMBP, is stronger acid than HMBP; moreover, its extractive behavior is very different from HMBP to some metal ions as a result of S atom replacing of O in HMBP.2In order to understand its extraction mechanism and regularity, we selected metal ions such as ZnⅡ and CdⅡ for preparing extracted complexes and analyzing their structure. The composition of the complexes, M(DTP)2 (M=Zn, Cd), were supposed by elementary analysis, and confirmed by FT-IR and 1HNMR spectra.

    A New Chemiluminescence Method for the Determination of Pyrogallol
    ZHUANG Hui-Sheng, WU Fang, WANG Qong-Er, CHEN Guo-Nan
    2000, 21(S1):  83-83. 
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    Pyrogallol(Py) is a chemiluminescence(CL) reagent with a low emission efficiency. The pyrogallol structural group is also found in molecules of many important natural and synthetic confounds, such as gallic acid humic acid and pyrogallol red. Studies of the metablism of phenolic compounds requires the development of specific and sensitive methods for the determination of pyrogallol. HPLC[1], spectrophotometry[2] and CL[3-7] have been used to determined polyphenols, but these methods are complicated or low sensitivity.In this paper, a new Chemiluminense(CL) analytical method for determination of Py was established.This method is more sensitive than those methods reported in the literature[3-7].

    Chiral Resolution of l, l'-Binaphthalene-2, 2'-Diol and its (-)-Menthyl Chloroformate derivatives by HPLC with Urea Derivative as Chiral Stationary Phase
    RUAN Tuan-Ping, CHEN An-Qi, AO Xiao-Ping, HUANG Pei-Qiang, JIN Li-Ren
    2000, 21(S1):  84-84. 
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    Optically pure l,1'-binaphthalene-2,2'-diols are very useful compounds for various application[1] such as catalyst ligands for asymmetric synthesis, the starting materials for other chiral binaphthyl catalysts and resolving agents for racemic compounds. Consequently, the preparation of optically pure l,l'-binaphthalene-2,2'-diols are of current interest Recently, new methods of resolution of racemic l,1'-binaphthalene-2,2'-diols utilizing (-)-(lR)-menthyl chloroformate as the derivatization agent have been developed[2,3]. To determine the optical purity of these 1,1'-binaphthalenes, it is necessary to develop a convenient and reliable method for the detection of each stereoisomers.

    A Study on Pharmacokinetic of Norfloxacin by Second Derivation Spectrophotometry
    LIN Xin-Hua, LI Chun-Yan, HUANG Jian-Fang, YE Hua-Zheng, CHEN Shao-Feng
    2000, 21(S1):  85-85. 
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    Norfloxacin (NFX) was the third era Pyridopyrimidinic acid antibacterial medicament, which was in common used to cure the infection of uretbra and respiratory tract, gonorrhea, and bacterium enteritis. By metabolizing in body, 60% of NFX in original shape were excreted in urine, so Pharmacokinetic of NFX was studied by determining concentration of NFX in urine. Till now, the methods of determining concentration of NFX in urine, such as fluorescence Spectrophotometry (with blank urine as antitheses[1]), HPLC[2] and microorganism[3] had been adopted, whose operation was numerous and trivial.

    Fluorometric Determination of Atmospheric Nox
    ZHAN Xin-Qi, LI Dong-Hui, ZHENG Hong, ZHU Qing-Zhi, XU Jin-Gou
    2000, 21(S1):  86-86. 
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    Nitrogen oxides in urban air are mostly from exhaust gases emitted by internal-combustion engines with a considerable impact on human health. It plays an important role in the generation of photochemical smog and photochemical oxidants such as ozone and peroxyacetyl nitrate (PAN). And it is a precursor of nitrous acid, nitric acid and fractions of solid nitrates which are important in the acid rain chemistry.

    Atomic Spectrometry
    Determination of Trace Quinhydrone by Enzymatic Kinetic Spectrophotometry
    LIN Xin-Hua, LI Chun-Yan
    2000, 21(S1):  87-87. 
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    Only trace of quinhydrone, a urease-inhibitor, can inhibit enzymatically promoting hydrolytic reaction of urea[1]. A new enzymatic inhibition kinetic spectrophotometry method[2] for determination of trace quinhydrone was obtained by urea and P-dimethylamino-benzadehyde (color reagent) developing action. In this reaction, maximal absorptive wavelength is 420 nm. The enzymatic promoting reaction rate, log (A0/A1),enzymatic inhibition reaction rate, log (A0/A2,and their difference, log (A2/A1), are measured by detecting the remains of urea. All factors (urease, urea and color reagent dosage; reaction temperature; heating time), effecting log (A2/A1) were investigated.

    Analytical Sciences
    Determination of Proteins at Nanogram Levels by Enhanced Rayleigh Light Scattering Technique with Tetra-Substituted Sulphonated Aluminum Phthalocyanine
    CHEN Xiao-Lan, LI Dong-Hui, ZHU Qing-Zhi, YANG Huang-Hao, XU Jin-Gou
    2000, 21(S1):  88-88. 
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    In recent years, Rayleigh light scattering has become a new tool for determining the content of biological molecules and studying the interaction mechanism of organic dyes with biological molecules[1]. According to the macroscopic fluctuation theory, in a transparent isotropic medium, when the light scattering is caused by molecular particles 20-fold smaller than the wavelength of the incident beam, the Rayleigh scattering law is obeyed, namely I∝1/λ4[2]. However, if the wavelength of the incident beam is close to that of the absorption band of the molecular particles which exist as aggregates, Rayleigh scattering will deviate from the law and enhanced RLS can be expected[3]. Using this technique, a method for the determination of proteins in aqueous solution has been developed based on the enhancement effect of proteins on die Rayleigh light scattering (RLS) of organic dyes[4].

    Hyphenation of FI Solid Phase Extraction (SPE) Micro-column with ICP-MS for On-line Separation and Determination of Trace Amount of Lead in High Salt Samples
    YANG Chao-Yong, CHEN Fa-Rong, ZHUANG Zhi-Xia, GU Sheng, WANG Xiao-Ru, MCLEOD C.W., MA Ren-Li
    2000, 21(S1):  89-89. 
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    The determination and monitoring of lead in the field of environmental science and life science are very important due to its high toxicity/ecotoxicity and bioavailability. The accurate and precise determination of Pb in the samples related to environmental and life sciences is still a great challenge to analytical chemists because of its extremely low concentration and complicate matrices in the samples.

    Study on the Basic Conformation of Proteins by Electrospray Ionization-Mass Spectrometry (ESI-MS)
    GU Sheng, SHEN Jin-Can, ZHUANG Zhi-Xia, WANG Xiao-Ru, GAO Gui-Ying
    2000, 21(S1):  90-90. 
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    Proteins are of great importance in many processes involving natural life, biology and descendiblity. Proteins have been analyzed using various chemical/biological methods. However with those traditional methods, the variety of information related to the conformation of protein complex is very difficult to be obtained The emergence of electrospary ionization-mass spectrometry (ESI-MS) makes it possible to obtain some characteristics information of the protein complexes[1]. Multiple charging is one of the hallmarks of electrospray ionization of macromolecules. The determination of macromolecules mass from the spectrum of multiply charged ions is facilitated by the coherence of charge states[2].

    Use of a Luminescent Bacterial Biosensor for Biomonitoring and Characterization of Toxicity of Seawater
    ZHUANG Zhi-Xia, YAN Zhen, CHEN Xi, LI Wei, WANG Xiao-Ru
    2000, 21(S1):  91-91. 
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    Rapid and continuous detection of environmental contaminants in effluents and waterways is important for protecting natural environments and public health, and for managing waster treatment systems. Although physicochemical methods have traditionally been employed for analyzing contaminants, monitoring using biological indicators has received increasing attention over the last few years for measuring toxic and bioavailable pollutants. A useful approach has been employing chemi-or bioluminescent reporter systems that involve whole bioluminescent microbes or biochemical reactions which provide rapid and visible responses to the presence of harmful chemicals, including heavy metal ions and petrcchemial industry waters. Coupling such biological detection systems with optical biosensors for environmental monitoring combines rapid response times, low costs and improved reproducibility.

    High Sensitivity Hyphenation System of Capillary Electrophoresis Combined Inductively Coupled Plasma Mass Spectrometer for Elemental Speciation Analysis
    ZHUANG Zhi-Xia, YANG Chao-Yong, CHEN Fa-Rong, GU Sheng, LI Qi, WANG Xiao-Ru
    2000, 21(S1):  92-92. 
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    The proper functioning of life is critically dependent on trace elements in a number of different ways. Some trace elements are highly toxic whereas others, considered essential, are needed for the accomplishment of life process. A surge of evidence during the past 20 years has been leading to the conclusion that it is not the total element content but that of a particular species that should be determined if valid information on the essentiality or toxicity of a given element is to be obtained[1-5]. Thus, speciation analysis has become one of the fastest developing areas of analytical chemistry towards the close of the 20th century[5]. The advantages of Capillary Electrophoresis include rapid analysis, low sample requirements, high separation efficiency and low operation costs[6]. The separation potential of CE,with superior detection capability of ICPMS make CE-ICPMS a powerful tool for metal speciation.

    Micro-Pt Array Electrode Towards CO Adsorption Investigated by Using In Situ FTIR Microscopy
    GONG Hui, LUO Tao, ZHOU Zhi-You, CHEN Sheng-Pei, SUN Shi-Gang
    2000, 21(S1):  93-93. 
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    The best-known quality of microelectrode is the low capacity of the interfacial double layer[1]. In this paper, we have designed specially and fabricated an array electrode of micro-Pt (μ-Pt). 16 μ-Pt (200μm in diameter) electrodes were arranged in a 4 x 4 array, and the distance between each neighboring μ-Pt is 200μm. The associating designed electronic board allows to connect any individual μ-Pt or collective μ-Pts by selection with potentiostat, so the properties of an individual μ-Pt or arbitrarily grouped μ-Pt can be investigated conveniently. Moreover, by employing the in situ FTIR Microscopy[2], the surface processes of CO adsorption on the array electrode were studied. Information at molecule level concerning the abnormal infrared effects (AIREs)[3] of individual μ-Pt subjected to a fast potential scan treatment and the interaction between μ-Pts (coupled action) have been obtained for the first time.

    Composition of the Essential Oil on Leaves of Crateva Trifoliata
    SONG Xiao-Ping, CHEN Guang-Ying, HAN Chang-Ri
    2000, 21(S1):  94-94. 
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    Crateva trifoliata (Roxb.) Sun growing in hainan island is often used to treat urinary disorders, stomach trouble and arthritis et al. in folk medicine. Especially to bone matrix hyperplasia, it has better curative effect. However, the study of its chemical components has not been reported. For exploiting this kind of native source, we studied the composition of essential oil of its leaves.

    Study on Essential Oil Components in Needles of Pinus Caribaea Morelet
    CHEN Guang-Ying, SONG Xiao-Ping, HAN Chang-Ri
    2000, 21(S1):  95-95. 
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    Pinus caribaea Morelet is one of pines with the fastest growth rate. Our country began to implant Pinus caribaea Morelet from 1963, which grew well in hainan and distributed widely. The essential oil of its needles is not only used for medicine, but also a kind of important natural perfume. However, the study of its chemical components has not been reported. For exploiting this kind of native source, we studied the composition of the essential oil of needles.

    Simultaneous Determination of Gold(Ⅲ) and Copper(Ⅱ) with Two-Way Stripping Voltammetry
    WEI Dong-Ping, HU Rong-Zong
    2000, 21(S1):  96-96. 
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    The simultaneous determination of Au(Ⅲ) and Cu(Ⅱ) by atomic absorption spectrometry[1,2], X-ray fluorescence[3] and differential-pulse polarography[4] have been reported. The apparatus used in spectrochemical analysis are complex and expensive. The method reported in reference[4] involves a poisonous electrode-DME(dropping-mercury electrode) and unsatisfied performance with the detection limit. We had reported the determination of trace Au(Ⅲ) or Cu(Ⅱ) by a sensitive tripping voltammetry with solid electrode[5], but there is no report about the simultaneous determination of trace Au(Ⅲ) and Cu(Ⅱ) by stripping voltammetry ever since.

    Rapid Determination of Organophosphorus and Carbamate Pesticide Residues in Vegetables and Fruits Using a Plant-Hydrolases Inhibition Technique
    ZHONG Shu-Ming, YUAN Dong-Xing, XU Peng-Xiang
    2000, 21(S1):  97-97. 
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    The wide use of toxic organophosphorus and carbamates pesticides in agriculture and the concern of its effects on die environment have called for the need of sensitive and portable detection methods in vegetable and fruit survey. The plant hydrolases can catalyze the hydrolysis of substrate 2,6-dichlorophenolindophenol acetate, changing its colour from yellow to deep blue in aqueous solution. When the plant hydrolases are in the presence of the pesticides, the enzyme activity decreases, resulting in the change of colour.

    Chemistry Resources on the Worldwide Web in China
    DAI Wei-Meng
    2000, 21(S1):  98-98. 
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    The World Wide Web (WWW) has become one of the most important ways for chemists to collect the newest information in chemistry. Many web sites provide comprehensive chemical information resources. In China, some special web sites have been established to provide information resources in chemistry. One of the most important web site is ChIN (The International Chemical Information Network, www.chinweb.com.cn or chin.icm.ac.cn) supported by Chinese Academy of Sciences and National Natural Science Foundation of China.

    Determination of Ultra-trace Rare Earth Elements in Cyclocarya Paliurus (Batal.) Iljinskaja Leaves by Inductively Coupled Plasma Mass Spectrometry with Microwave Digestion/Extraction
    WU Xi-Hong, SUN Da-Hai, SUN Zhen-Hua, WANG Xiao-Ru, LI Lei
    2000, 21(S1):  99-99. 
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    In recent years, the analysis of rare earth elements (REEs) in health foodstuff and natural medicines has become a subject of considerable interest. Sufficient evidence has shown that some of REEs play important roles in clinical efficacy:such as the function of reducing blood sugar, cancer resistance, anti-inflammation and improving immunological capability, et al. The mechanisms of the bioactivity of REEs to reduce blood sugar have been reported in Ref.

    Wavelet transform-based Curve Fitting
    ZHANG Xiu-Qi, ZHENG Jian-Bin, GAO Hong
    2000, 21(S1):  100-100. 
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    Curve fitting methods are now widely applied both qualitative and quantitatively to separate overlapping peaks in composite profiles. Nevertheless, the achievement of a good representative fit requires the knowledge of five parameters:the number of component bands, their positions, shapes and widths, and the form of the baseline. Clearly, curve fitting is considerably facilitated if approximate values for some of the parameters are known at the outset. Up to present, there are many methods employed for improving the curve-fitted conditions[1,2]. Wavelet transform is a high performance signal processing technique developed from the Fourier transform.

    Element Speciation in the Extracts of the Cyclocarya Paliurus (Batal.) Iljinsk. Leaves Determined by SEC and ICP-MS
    XIE Ming-Yong, LI Lei, ZHUANG Zhi-Xia, WANG Xiao-Ru
    2000, 21(S1):  101-101. 
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    Cyclocarya paliurus (Batal.) Iljinsk. (CPs) is a kind of Traditional Chinese Medicine (TCM) and a health food resource. Both water and alcohol extracts from its leaves were found to be bioactive, having the therapeutic functions of reducing blood sugar and blood pressure, anti-tumor, etc. In the process of extracting, the Elements Related to Blood Sugar (ERBS) in the leaves is also transferred into the infusion during the extracting of organic compounds from them.

    The Fabrication of Optochemical Sensitive Sol-Gel Film for Oxygen Measurement
    JIANG Ya-Oi, ZHONG Zhen-Ming, CHEN Xi, LI Wei, WANG Xiao-Ru, WONG Kwok-Yin
    2000, 21(S1):  102-102. 
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    The ruthenium complex is a very attractive class of compound for luminescence oxygen-sensing application, due to its high photochemical stability, high excitation efficient, relatively long fluorescence lifetime, large Stokes shift and strong absorption in the blue-green region of the spectrum The complex[Ru-tris(4,7-diphenyl-1, 10-phenanthroline)] used in this work was immobilized in a microporous silica matrix structure via the sol-gel synthesis.

    An Optical Relative Humidity Sensing System
    JIN Xing-Liang, LI Wei, SUN Da-Hai, ZHUANG Zhi-Xia, CHEN Xi, WANG Xiao-Ru
    2000, 21(S1):  103-103. 
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    The relative humidity (RH) of air is an important parameter that needs to be measured in many industries. Brook et al.[1,2] studied the response of Nafion films containing Crystal Violet to the relative humidity; Raimundo et al.[3] investigated the composition of Nafion-Crystal Violet films and their casting processes. In this paper, the sensing film was prepared by entrapped Crystal Violet in the commercial Nafion film. The dry air was commercially available and the 100% RH air was obtained by bubbling dry air into a series of bubbling flasks filled with deionized water. A spectrophotometer was employed to monitor the absorption changes of the film at the range of 400nm to 700 nm.

    Fibre-Optic pH Probe Based on the Use of An Immobilized Amino Fluoresecein Indicator
    JING Miao, LI Wei, ZHUANG Zhi-Xia, CHEN Xi, WANG Xiao-Ru
    2000, 21(S1):  104-104. 
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    Optical sensors can offer advantages over electrochemical sensors with respect to reduced interferences and ease of use for remote sensing[1]. The first fiber optic pH sensor was developed for in vivo measurements by Peterson et al[2]. This sensor relates pH to the absorbance of the base from of an immobilized dye. Subsequently, a pH sensor based on the fluorescence of immobilized fluoreseinamine was reported. The sensor involves immobilizing the amino fluoresecein (AF) complex within a porous sol-gel-processed film. Sol-gel process has many advantages as a method of immobilization[3]. At ambient temperature, it allows the fabrication of a tough, inert, porous glass material with a high surface area. Sol-gel technology provides a viable approach to prepare stable, optically transparent host matrices for the design of materials for sensor, optical, chromatographic[4], and catalytic applications. Alternatively, organosilicon precursors of the general formula can be hydrolyzed and co-condensed with tetraethoxysilane to form an organic-inorganic hybrid. An aliquot of the resultant sol can be spin cast or dip coated on a planar substrate to form a thin film.

    Chemistry in Energy Sciences
    Exploring the Multi-Scale Nature of Complex Systems in Chemical Engineering
    LI Jing-Hai
    2000, 21(S1):  105-105. 
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    Multi-phase reactors in chemical engineering are mostly complex systems, characterized by non-linearity and non-equilibrium. Scale-up of these reactors has been challenging engineers and scientists for decades, and its solution is not likely with the use of traditional approaches without transdisciplinarity effort. This presentation explores the intrinsic mechanism of the scale-up effect and the role of transdisciplinarity in scaling-up multi-phase chemical reactors by discussing two approaches-the multi-scale approach and the pseudo-particle approach.

    Preparation of Spinel Cathode Materials Li1+xMn2-xO4 by In-situ Redox Precipitation Method for Lithium Rechargeable Batteries
    LIU Xing-Quan, YU Zuo-Long
    2000, 21(S1):  106-106. 
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    Spinel Li1+xMn2-xO4 has been studied extensively as a promising cathode material for lithium rechargeable batteries with high energy density due to the following advantages. (1) it is less expensive; (2) it is less toxic; (3) it is easier to prepare than layered LiCoO2 and LiNiO2. The preparation methods have important and remarkable effects on the electrochemical properties of spinel Li1+xMn2-xO4 cathode material. Li1+,Mn2_x04 powders are typically synthesized by solid state reaction which consists of extensively mechanical mixing and intermitted grinding[1,2]. This treatment is detrimental to the quality of the final product because of the resulting inhomogeneity, irregular morphology, larger particle size with broader particle diameter distribution, and poor control of stoichiometry resulted from lithium loss at high temperature for long time. In order to achieve good efficiency of lithium utilization at high current and high reliability of lithium rechargeable batteries, we developed a new synthesis process which was called as in-situ redox precipitation method[3]. By this method, the Li1+xMn2-xO4 cathode material with good homogeneity, uniform morphology and narrow particle-size distribution as well as excellent electrochemical performance can be easily produced at lower temperature and in a shorter processing time. In this paper, our partial findings were reported.

    Catalyst Deactivation in Low Temperature Slurry Methanol Synthesis C Process
    LI Shun-Fen, YANG Xian-Gui, LUO Shi-Zhong, DAI Han-Song, WU Yu-Tang
    2000, 21(S1):  107-107. 
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    A catalyst system composed of Cu-based catalyst and alkaline methoxide for low temperature methanol synthesis have high activity and high methanol selectivity, but long run results show that catalyst deactivation has restricted the commercial application of the process. The experimental results showed that the deactivation rate of carbonylation catalysts is much more faster than that of hydrogenolysis catalysts, and the detailed studies including chemical analysis, gas chromatograph, FTIR and XRD demonstrated that most part of sodium methoxide is transformed to sodium formate after long time run.

    Polymer Electrolyte Fuel Cells for Mobile and Stationary Applications-State of the Art and Recent Progress
    LI Qing-Feng
    2000, 21(S1):  108-108. 
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    As a clean and efficient technology, fuel cells are expected to provide a practical form of power generation. Among others, polymer electrolyte membrane fuel cells (PEMFC) are receiving more and more attention due to their abilities as power generators for both stationary and transportation applications. The main features of the PEMFC are high power density, low operational temperature, pollution free operation,and all-solid construction and therefore less corrosion[1].

    Methane Clear Combustion at High Temperature over NiO/ZrO2 Series Catalysts
    JI Wen-Xin, WANG Yuan-Yang, GUO Yu-Mei, LUO Fa-Liang
    2000, 21(S1):  109-109. 
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    Natural gas would play a predominant role in the energy structure in this new century. However, only at high temperature natural gas could combust with high efficiency, resulting in some pollution gases such as NOx and CO produced if air was employed as oxygen resource. Catalytic combustion was considered as a prospective route to solve this problem. Noble metals shown good performance but with limited resources[1], so that many attentions were focused on the development of non-noble metals materials with good high temperature properties, among which ZrO2 supported series might be the first choice[2]. Therefore, methane (over 95% of natural gas) combustion performance on this types of catalysts should be investigated in detail.

    Full-dimensional Time-dependent Quantum Dynamics in Unimolecular Dissociation of HCO
    GUO Rui, ZHAO Xin-Sheng
    2000, 21(S1):  110-110. 
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    As an important species in atmospheric and combustion chemistry, unimolecular dissociation of HCO has attracted extensive experimental and theoretical interests ever since 1960's[1-3], which include calculations of potential energy surfaces based on high-level ab initio results[4].

    Investigation of Partial Oxidation of Methane over Rh/SiO2 catalyst by TP-MS
    WU Ting-Hua, YAN Qian-Gu, WENG Wei-Zheng, YANG Le-Fu, WAN Hui-Lin
    2000, 21(S1):  111-111. 
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    Partial oxidation of methane (POM) was investigated over Rh/SiO2 catalyst using several techniques combined with MS, such as temperature programmed desorption (TPD), temperature programmed reduction (TPR), temperature programmed surface reaction (TPSR), temperature programmed reaction, and CH3I chemical trapping reaction.

    The Adsorption and Activation of Methane over Ni-Based Catalyst
    HU Chang-Wei, CHEN Yao-Qiang, GONG Mao-Chu, YANG Hua-Qing, ZHANG Ai-Lian, TIAN An-Min
    2000, 21(S1):  112-112. 
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    The activation of methane attracts much attention recently for its great importance. The chemisorption and reaction of methane over Ni/Al2O3 catalysts were carried out together with an ab initio investigation of the modeled system in present study.

    Simultaneous Production of Hydrogen and Carbon Nano-Materials from Decomposition of Methane
    LI Yong-Dan, CHEN Jiu-Ling, QIN Yong-Ning, CHANG Liu
    2000, 21(S1):  113-113. 
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    From the decomposition of methane, hydrogen without carbon oxides can be produced with a high energy-efficiency, which is attractive for its suitability of utilization in the fuel cells. At a same time carbon nano-materials with attractive texture and structure can be produced in a large amount. Toward a simultaneous bulk production of hydrogen and nanocarbon, catalysts based on nanometer scale nickel particles prepared from a hydrotalcite-like anionic clay precursor have been designed and tested to fit the process goals. For hydrogen production, as the equilibrium methane conversion of the reaction increases with the increase of the reaction temperature, the process is commercially more attractive if it can be operated at a temperature higher than 1073 K. However, a nickel catalyst has a maximum activity for nanocarbon production at 923 K. Modification of the catalyst with doping of copper increased the activation temperature and leads to a production of nanocarbon with an tubular structure. The feasibility and the challenges met for the coupling of the two process goals is discussed, and some promising results are presented in this work.

    The Preparation of Ionic Liquid Catalysts and Their Catalytic Performance
    LUO Fa-Liang, WANG Yuan-Yang, WANG Fu-Qiang, JI Wen-Xin
    2000, 21(S1):  114-114. 
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    Ionic liquid, a new type catalyst, was developed in recent years, on which some good catalytic performance appeared in some reactions such as olefins' oligomerization, hydrogenation and Freidel-Crafts reaction just for their strong electrophilic catalysis[1]. However, it was reported that only in vacuum and seal condition ionic liquid could be prepared with the halogerated hydrocarbon and heterocyclic compounds or their homologues[2]. So it was necessary to develop a new method to synthesize ionic liquid. Therefore, inert gases (such as N2) protection instead of vacuum was employed in this experimental, and the rules of preparation parameters on the products' type and yield were investigated, based on which the catalytic performance of these ionic liquid was studied in a model reaction of new compound synthesis from methane and carbon dioxide.

    Pre-reduced Activated Carbon-Supported Molybdenum-Based Catalysts for the Production of Mixed Alcohols from Synthesis Gas
    LI Xian-Guo, FENG Li-Juan
    2000, 21(S1):  115-115. 
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    Unsupported or supported Mo-based catalysts have been widely employed in petroleum industry, for hydrotreating[1],and for the production of hydrocarbons[2] and alcohols[3] by hydrogenation of CO (or CO2). Oxides, such as alumina, silica, silica-alumina, are commonly used as the supports for these purposes. Carbon-supported materials have been claimed to have potential advantages over oxide-supported ones, such as lower tendency of carbon deposition[4], less dehydration and thus less secondary reactions. Here we present results on mixed alcohol synthesis over H2-prereduced C-supported Mo-based catalysts.

    In-situ Raman Studies on the Oxide Species of Cathode in MCFC
    CHEN Li-Jiang, CHENG Xuan, FENG Zu-De, LIN Chang-Jian
    2000, 21(S1):  116-116. 
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    In MCFC the mechanism of cathode reaction is more complex than that of anode reaction. It is very important to clarify the reaction mechanism of cathode in order to direct the selection of cathode materials. The oxide species present in molten carbonate is the key to understand the mechanism of cathode reaction. Although there have been many papers to discuss the oxide species formed at cathode, no general conclusions have been reached so far, some results even contradicted. Appleby and Nicholson stated that peroxide ion appears to be the predominant species in the Li/K eutectic, but some other researchers concluded that the dominant species is superoxide ion in this melt.

    Use of Heteropoly Compounds in Natural Gas Sweetening and Sulfur Recovery
    WANG Rui
    2000, 21(S1):  117-117. 
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    Among the numerous H2S removal methods developed by now, liquid redox process with iron chelate base absorbent has gained the most attention, but the amendment of absorbent stability is still a problem[1,2]. An innovative approach to liquid redox process involving the use of heteropoly compounds appears to be a promising resolution to natural gas sweenting and sulfur recovery, to which an introduction will be given in this presentation.

    The Mass Transfer of Proton on Meniscus Nafion/Pt/HOPG Electrode
    XIAO Xiao-Ming, ZENG Yue, XIE Qing-Ji, YU Shang-Ci, LI Ze-Lin
    2000, 21(S1):  118-118. 
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    Proton-exchange membrane fuel cells (PEMFCs) recently have been studied extensively because of their high performance[1-3]. Since a small contacting area between the platinum catalyst and polymer electrolyte in PEMFCs, the platinum utilization is very important for this kind of cells. In order to improve the platinum utilization, Nafion solution is often impregnated into the gas-diffusion electrodes of PEMFCs. We introduced a partially immersed Nafion-coated electrode, Nafion/Pt/HOPG(highly oriented pyrolytic graphite) as a model electrode in PEMFC, to examine the effects of Nafion coating on the mass transport of hydrogen and proton at the meniscus and supermeniscus formed on the electrodes.

    The Newly Developed Hydrocracking Catalysts for High-Quality Middle Distillates in FRIPP
    YU Zheng-Nan, DING Lian-Hui, GUAN Ming-Hua, WANG Feng-Lai, HU Yong-Kang
    2000, 21(S1):  119-119. 
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    Worldwide demand for both jet fuel and diesel is growing considerably. In Europe and Asia, the demand for middle distillates is clearly higher than that for lighter products. Hydrocracking is an important technology to increase high-quality middle distillates; the key of hydrocracking technology is catalyst. Recently, both amorphous and zeolite-containing hydrocracking catalysts have been developed to keep up with the changing market needs. In this article, pilot plant results with the amorphous and zeolitic hydrocracking catalyst are described.

    An Ultra Hydrophobic Y Zeolite Used In Hydrocracking Catalysts
    RUAN Cai-An, YIN Ze-Qun
    2000, 21(S1):  120-120. 
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    An ultra hydrophobic Y zeolite is a new modified Y zeolite developed by Fushun Research Institute of Petroleum and Petrochemicals. The characteristics of this zeolite are higher crystallinity, smaller unit cell size, good hydrophobicity, higher ratio of silica to alumina in framework, higher surface area, more secondary pore and smaller non-framework aluminum.

    Mechanistic Study of Partial Oxidation of Methane to Syngas over c Pd/SiO2 Catalyst
    WENG Wei-Zheng, YAN Qian-Gu, LIAO Yuan-Yan, LIU Ying, WAN Hui-Lin
    2000, 21(S1):  121-121. 
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    Partial oxidation of methane (POM) to make syngas has been largely studied in recent years because of its potential to reduce the cost of syngas. Two reaction schemes have been proposed for the reaction:one is the sequence of combustion of CH4 followed by reforming of unconverted CH4 with CO2 and H2O,and the other is the direct partial oxidation of CH4 to CO and H2 without the experience of CO2 and H2O as reaction intermediates. In the industrial process, if the combustion-reforming mechanism predominantly contributes to the conversion of methane to syngas, severe heat management problems have to be taken into account. Therefore, the elucidation of the reaction pathway is of vital importance. In this paper, in situ time-resolved FTIR (in situ TR-FTIR) spectroscopy was used to study the POM reaction over lwt%Pd/SiO2. The results of catalytic performance evaluation on the POM reaction over lwt%Pd/SiO2 under different space velocity are also presented. It is expected that the additional proof can be presented to interpret POM mechanism.

    Studies of Cephalosporin C Purification by Ultrafitration
    LI Chun-Yan, HE Xu-Min, FANG Fu-Lin, LAN Wei-Guang, XIA Hai-Ping
    2000, 21(S1):  122-122. 
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    Cephalosporin C was produced with fermentation technique. There are many impurities (mycelium, protein et al) in its fermentation liquor, which can be removed by ultrafitration membrane separation. The ultrafiltration technique has been used for purifying the fermentation liquid of antibiotics[1-2],however, its application in extraction of Cephalosporin C from its fermentation liquor has not been reported. In this paper, we use Ultra-flo ultraflitration membrane system (concludes UF-54 pilot plant, flat board membrane module, thin composite membrane of 30 thousand reject molecular weight) to purify #1-#3 fermentation liquors of Cephalosporin C, which were not pretreated except acidification(pH=3).

    Application of 2-Keto-L-gulonic Acid Extraction by Ultrafiltration
    LI Chun-Yan, HE Xu-Min, FANG Fu-Lin, LAN Wei-Guang, XIA Hai-Ping
    2000, 21(S1):  123-123. 
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    2-Keto-L-gulonic acid (for short gulonic acid), which was produced with pioneering twice fermentation technique in China, is an intermediate of the production of Vitamin C. The impurities (protein, mycelium et al.) in the fermentation liquor can be removed by heat precipitation of the original process, however, gulonic acid is heat-sensitive, its yield will be reduced when heating. The ultrafiltration membrane separation technique has been used to extract gulonic acid from Vitamin C fermentation liquor[1], which is operated at room temperature, with a pretreatment of the fermentation liquor before ultrafiltration, to avoid the jam of membrane.

    Improved Alkylation Technology with Solid Acid Material as Catalyst
    NAN Jun, DUAN Wei-Yu, HE Jin
    2000, 21(S1):  124-124. 
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    Alkylation of isobutane with C3-C5 olefins has been practiced commercially since the 1940s. Indeed, alkylation which is mainly formed by multibranched paraffins,has a rather low vapor pressure, high octane numbers (RON and MON) and a low sensitive factor. In the past twelve years, about 20 alkylation plants using either HF or H2SO4 catalysts have been built in China[1]. Concerns have been raised about the safety and environmental impact of the handing of the very large quantities of these liquid acids used in alkylation today and a great deal of time and money has been spent in the past 20 years in attempts to develop alkylation catalyst and process that are more environmentally friend than current industrial technology[2]. To date,no process has been announced that seems to be of commercial interest, but two possible exceptions (Topöse process and UOP Alkylene process) are discussed in this paper. Many difficult technical challenges must be surmount in the next few years for a new solid catalyst alkylation process to be commercialized successfully.

    A New Method for Energy-Saving Tray Design
    LIU Qing-Lin, LI Peng, ZHANG Zhi-Bing
    2000, 21(S1):  125-125. 
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    With the enhancement of people's awareness of protecting our resources and environment, it becomes an urgent subject to make effective use of resources and to reduce process energy consumption. Distillation, a major energy-consumption unit operation in chemical process, has been analyzed intensively in terms of entropy generation rate. By using various kinds of thermodynamic analysis methods, chemical engineers have gained many valuable results. These researches, however, merely focused on different technological processes and various process conditions. The effect of tray structural parameter on process entropy generation has largely been neglected.

    Sorption and Diffusion of Water and Ethanol in Polyethersulfone Hollow Fiber Membranes
    LI Jun, LIU Hong-Lai, HU Ying
    2000, 21(S1):  126-126. 
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    Study on solubility and transport phenomena of penetrant in polymer membrane is of significance for appraising separation ability, selecting membrane materials, designing or exploring membrane separation technology. There are many ways, in which the sorption/desorption method is a more acceptable one for its relatively simple procedures and affable conditions, to study the transport properties of penetrant in polymer. As our best knowledge, many experiments and measured data are reported for flat sheet, while no for hollow fiber membrane using sorption/desorption method. In this paper, we hope to appraise the separation ability of hollow fibers through sorption experiments of water and ethanol vapors in fibers by a proposed separation factor in infinite dilution.

    Anaerobic Fermentation Treatment of Bagasse Alkaline Spent Liquor
    YE Li-Yi
    2000, 21(S1):  127-127. 
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    The bagasse is the waste of sugar-making industry, it contains 50% of cellulose and is the major material of pulp and paper industry in Guangdong, Guangxi, Fujian, Sichuan provinces. In industry, the bagasse chemical pulp is often made by using alkali, most of bagasse pulp mills without recovery of soda and organic materials, and are discharged into the river because of technologic and economic reason. This makes serious pollution to the water and affects the ecological balance.

    Fabrication of LiCoO2 at Low Temperature for Battery Usage
    ZHU Guang-Ming, WU Guo-Tao, YOU Jin-Kua, LIN Zu-Geng
    2000, 21(S1):  128-128. 
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    Reaction of CoO2 with air resulted in its protonization to form CoOOH. In light of the intimate relationship between LiCoO2 and CoOOH, reaction by "soft chemistry" ion exchange was undertaken to fabricate LiCoO2 at low temperatures. By way of a reaction between CoOOH and LiOH-H2O in a highly basic environment, LiCoO2 with good crystallinity was formed at 100℃. This new method of fabrication results in a 700-800℃ decrease in fabrication temperature compared with traditional methods and in subsequent cost savings. Electrochemical behavior was initially hampered by insertion of carbonate species which could be removed thermally at moderate temperatures.

    Comparative Study on the Structure and Electrochemical Properties of RE(Ni,Co,Mn,Ti)5 (RE=La,Ce,Pr,d) Alloys
    ZHU Guang-Ming, LEI Yong-Quan, CHEN Li-Xin, YANG Xiao-Quang, WANG Qi-Dong
    2000, 21(S1):  129-129. 
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    As main composition of mishmetals, the four pure light lanthanide elements La, Ce,Pr or Nd was used individually instead of Ml or Mm as RE in preparation of AB5 typed hydrogen storage alloy RE(Ni,Co,Mn,Ti)5. The four alloys, La(Ni,Co5Mn,Ti)5, Ce(Ni,Co>ln,Ti)5, Pr(Ni,Co,Mn,Ti)5 and Nd(Ni,Co,Mn,Ti)5 were then tested, characterized and compared in the their cell volumes (Vcell), P-C-T curves, and mainly electrochemical characteristics against charge/discharge cycles, including the activation cycle number (na),the maximum discharge opacity at 50 mA/g charge/discharge rate (C50,max), the high-rate-dischargeability and the rate of decay (-dC/dn). These properties are compared and analyzed to reveal the difference of the effects of each element on the electrochemical properties of rare earth based AB5 typed hydrogen storage alloy.

    EIS Study on the Electrochemical Properties of RE(Ni,Co,Mn,Ti)s Alloys (RE=La,Ce,Pr,Nd) at Different Depths of Discharge (DOD)
    ZHU Guang-Ming, CHENG Shao-An, LEI Yong-Quan, CHEN Li-Xin, WANG Qi-Dong
    2000, 21(S1):  130-130. 
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    In the present investigation, EIS was employed to study the electrode kinetics of AB5 typed RE (Ni, Co, Mn, Ti)5 alloy and compare the difference of rare earth component effects when pure La, Ce, Pr or Nd was used individually for RE in the alloy respectively.

    Electrochemical Performance Comparability of Some Re(Ni,Co,Mn,Ti)5 Alloys with the Same Specific 4f Electronic Concentration in Its Rare Earth Side
    ZHU Guang-Ming, LEI Yong-Quan, CHEN Li-Xin, YANG Xiao-Quang, WANG Qi-Dong
    2000, 21(S1):  131-131. 
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    In order to reveal the principle for the effects of rare earth component on the electrochemical properties of AB5 typed alloy, six series of RE (Ni,Co,Mn,Ti)5 alloys of two main element in mishmetal La, Ce, Pr or Nd as its A side element of AB5 typed hydrogen storage alloy were prepared and the effects of variation in A side element were systematically studied. The general formulae may be expressed as A1-αA'αB5, where the A1-αA'α denotes LaαPr1-α,Ceα'Pr1-α', Laα"Ce1-α",or CeβNd1-β(0 ≤ α,α',α",β ≤ 1) and Bis Ni1-a-b-cCoaMnbTic. It's found that, with the same specific 4f electronic concentration, the variation of discharge capacity is quite similar.

    Improve Electrochemical Performance of LixCoO2 by Proper Heat Treatment
    ZHU Guang-Ming, WU Guo-Tao, YOU Jin-Kua, LIN Zu-Geng
    2000, 21(S1):  132-132. 
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    While LiCoO2 has a large theoretical capacity of 274 mAh/g, only 50% of it may be used for commercial Li-ion battery applications due to rapid decay in capacity with cycle number.

    Investigation of Partial Oxidation of Methane to Syngas on Rh/SiO2-Using 1H-NMR
    WU Ting-Hua, YAN Qian-Gu, CHAO Zi-Sheng, LUO Chun-Rong, YE Jian-Liang, WAN Hui-Lin
    2000, 21(S1):  133-133. 
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    In our previous work, POM has been investigated by the pulse reaction with CH4 and CH4/O2 respectively, on Rh/SiO2 catalyst. Kinetic isotopic effect was also studied by using CD4 and CD4/O2. The results suggest that POM may proceed most possibly via a mechanism of surface carbon species reacting with surface oxygen. In the present work, 1H MAS NMR was utilized to investigate the POM mechanism in aiming of presenting additional evidence.

    The Effect of the Surface Oxygen Concentration of Catalysts on Activation of Methane
    YAN Qian-Gu, WU Ting-Hua, LUO Chun-Rong, WENG Wei-Zheng, GUO Weng, YANG Le-Fu, WAN Hui-Lin
    2000, 21(S1):  134-134. 
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    The improvement of synthesis gas production process is a very important research field in natural gas industry. Recent years, many researchers have suggested that catalytic partial oxidation of methane could be an attractive alternative as a process for synthesis gas production owing to its many advantages. So, it is very important to study the activation over supported metal catalyst. Activation of methane over supported metal catalysts was investigated using MS-pulse techniques in the absence of gaseous oxygen.

    Investigation of POM Reaction Over Rh/SiO2 Catalyst Using XPS
    WU Ting-Hua, YAN Qian-Gu, CAO Zi-Sheng, LUO Chun-Rong, WENG Wei-Zheng, WAN Hui-Lin
    2000, 21(S1):  135-135. 
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    By means of XPS, the binding energy and the concentration of the surface element were characterized, before and after the catalyst was exposed to CH4 and/or O2 at different temperature (from room temperature to 773 K) and at different amounts with different sequence. It was found that CHx(x=l~3) species were formed over the catalyst closed to CH4 or CH4/O2. For CH3,CH2 and CH species, the C1Sbinding energies were ca. 285.5 eV, 284.5 eV and 283.5 eV, respectively.

    Ag/La0.6Sr0.4MnO3 Catalysts for Complete Oxidation of Alcohol Fueled Car Exhausts
    WANG Wei, LIN Guo-Dong, ZHANG Hong-Bin
    2000, 21(S1):  136-136. 
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    Alcohol fuel has been suggested as an alternative for car operation to reduce gasoline consumption[1]. However, being different from that of gasoline car, alcohol-fueled car exhaust principally contains unburned alcohol and formaldehyde/acetaldehyde[2]. These volatile C1/C2 organics may have an undesirable impact on air quality. Most of the existing catalysts for complete oxidation of alcohol are precious metal catalysts supported by γ-Al2O3[2,3].

    Chemistry in Life Sciences
    Interaction of Phenylpropanoid Glycosides with Nucleotides and DNA:Kinetic and Molecular Modeling Study
    FAN B. T., ZHENG R., ZAKRZEWSKA K., JIA Z., SHI Y., PANAYE A., DOUCET J. P., FASSIN. El, DELALANDE O.
    2000, 21(S1):  137-137. 
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    Phenylpropanoid glycosides (PPGs) are substances extracted from Pedicularis. They have been largely studied for their interesting biological and pharmacological properties[1-3], in particular, their double role in the protection of DNA:preventing the DNA bases from radical attack, and rapidly repairing damaged DNA[4-6]. A series of kinetic measurements has been performed with different deoxynucleotide radicals. Two major remakes can be done from the experimental results:(1) the reactivity of PPGs seems to depend on the number of phenolic hydroxyl groups; (2) the reactivity depends upon the positions of these groups. These observations are in agreements with the experiments performed on tumour cells.

    Nanometer Scale Imaging and Biochemical Sensing
    TAN Wei-Hong
    2000, 21(S1):  138-138. 
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    This seminar will cover two research topics in our group. The first one is nanometer scale sensing with living biological cells. In the biomedical sciences and technologies, the greatest advances in the last decade have been inspired by the genome project. What comes after the deciphering of the genetic code? Certainly one next step is the biochemistry driven by the gene, from the cellular nucleus to its organelles, cytoplasm and beyond. One important goal is to follow in real time the biochemical kinetics and dynamics of the living cell, much of which is in terms of small ions and biomolecules. Using both optical microscopy/spectroscopy and scanning probe microscopy, we have imaged single living cells and probed single molecule interactions.

    DNA-modified Surfaces and Their Applications
    PANG Dai-Wen
    2000, 21(S1):  139-139. 
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    As is known, DNA biosensors and DNA chips are now of great interest in life sciences, and they are being highlighted by molecular biologists and chemists because of their potential applications in biomedical fields, especially in disease diagnosis1[1-3]. In addition, with the development of molecular biology there have been increasing demands for new microsample and convenient methods for DNA or gene studies. In most cases of these researches, an extremely important problem is usually to structure DNA-modified surfaces.

    Use of Atomic Force Microscopy to Determine the in vitro Growth of Hydroxyapatite Crystals from Mammalian Skeletal Tissues
    ZHANG Jin, LIU Zhong-Fan, J. KIRKHAM, D. A. SMITH, C. ROBINSON
    2000, 21(S1):  140-140. 
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    The control of hydroxyapatite crystal deposition and growth has long been thought to be mediated via the proteins of the extracellular matrix[1]. However, the precise mechanisms remain obscure. Dental enamel is the most extreme example of mammalian biomineralisation and provides an excellent model for studies of biological hydroxyapatite crystal growth. During its development, enamel passes through a number of discrete stages which have been defined both chemically and histologically. Elucidation of these mechanisms would be an important step in the design of novel therapeutics and treatment of osteopathologies. Unfortunately, despite a great deal of in vitro work using indirect measurements of crystal growth (for example by depletion of ions from solution) there have been no models to date capable of measuring crystal growth directly and in real time. Atomic force microscopy (AFM) has provided unprecedented opportunities for the imaging of biological specimens, generating quantitative data in three dimensions with molecular resolution.It is ideally suited for biological imaging as specimens do not need to be dehydrated, fixed, stained or coated and, most importantly, imaging can be carried out under fluids, under the biological conditions of choice[2-3].

    Ab Initio and MNDO Calculation of the Intermediates of N-Diisopropylphosphoryl L-lspartic Acid
    CHEN Zhong-Zhou, TAN Bo, LI Yan-Mei, ZHAO Yu-Fen
    2000, 21(S1):  141-141. 
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    Many biological processes are regulated by the phosphorylation and dephosphorylation of amino acid residues in the proteins[1]. High-coordinate phosphorus intermediates forming from amino acid residues in protein are of great importance in the process of phosphorylation and dephosphorylation of protein. It has been proposed that the mechanisms of phosphorylation through penta-coordinate intramolecular mixed carboxylic-phosphoric anhydride intermediates[2]. It was found that α-COOH group[3] and β-COOH group[4] in aspartic acid had different activities in the ester exchange on phosphorus. So it is important to discuss which carboxylic acids is involved in the penta-coordinate phosphorus intermediate of aspartic acid.

    Effect of Carrier on Activity of Immobilized Lipase in the Resolution of Naproxen
    XU Yi, LI Shu-Ben, XIN Jia-Ying, WANG Lai-Lai, XIA Chun-Gu
    2000, 21(S1):  142-142. 
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    Several kinds of immobilization carrier were used for the resolution of naproxen by lipase from Candida rogusa in an aquous-organic biphase system[1]. It was found that the nature of carrier has obvious effect on the activity of immobilized enzyme. From the table below we can see that MCM-41 molecular sieve showed the highest activity, while the celite modified by DMCS showed the lowest activity.

    Design, Synthesis and Biological Activity of Benzimidazole and Aminophenol Based Factor Xa Inhibitors
    ZHAO Zu-Chun (Spring), SHAW Kenneth, ARNAIZ Danny, GRIEDEL Brian, SAKATA Steve, WU Shung, XU Wei, GIULFORD William, LIANG Amy, TRINH Lan, POST Joe, MORRISSEY Michael
    2000, 21(S1):  143-143. 
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    The serine protease factor Xa (FXa) is a key enzyme in the blood coagulation cascade, acting at the convergent point of the extrinsic and intrinsic pathways. The serine protease factor Xa (FXa) is a key enzyme in the blood coagulation cascade, acting at the convergent point of the extrinsic and intrinsic pathways. In our search for Fxa inhibitors as novel anticoagulants we identified the active isomer of the published FXa inhibitor, 2,7-bis-(4-amidinobenzilidine)-cycloheptan-l-one (BABCH), as the (Z, Z) isomer (ZK-805412, FXa Ki=0.66 nM). This photochemically labile (Z, Z) isomer has served as a conformationally rigid template for the development of distinct classes of potent, selective and orally active FXa inhibitors. Template evolution, in vitro SAR studies as well as our efforts to optimize in vivo parameters will be discussed.

    Design, Synthesis of N-benzoyloxy-thiono-1,8-naphthalimides as Novel DNA Photocleavers
    QIAN Xu-Hong, YAO Wei, CHEN Gang
    2000, 21(S1):  144-144. 
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    In recent years, It is of great interest to the design and synthesis of DNA photocleaving reagents that can generate active species by long-wavelength UV-light (λ>350nm) or more preferably by visible light irradiation. Our studies are based upon 1,8-naphthalimide-derivitives, which usually exhibit strong visible absorption and good DNA intercalative binding abilities.

    Microfabricated Disposable Electrochemical DNA Sensors
    XU Dan-Ke, LIU Zhi-Hong, MA Li-Ren
    2000, 21(S1):  145-145. 
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    Hybridization analysis is one of the most powerful methods of nucleic acid assays, including diagnostics of genetic disorders and infections of various etiologies. The biosensor detection allows an assay to be simplified and automatized[1,2]. In this report a new electrochemical biosensing method based on coupling avidin-alkaline phosphatase(AV-AP) to the biotinylated oligonucleotide has been developed.

    Comparison of the Metabolism of Eprinomectin in Lactating Dairy Cattle, Beef Cattle and Rats
    ZENG Zhao-Pie, ANDREW Nick, NARASIMHAN Nachu,VENKATARAMAN Kalpana, HALLEY Bruce
    2000, 21(S1):  146-146. 
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    Eprinomectin is a parasiticide used in beef and dairy cattle. It was not extensively metabolized in either cattle or Spranue-Dawley VAF rats, All the metabolites detected in cattle tissues and milk were also detected in rat tissues and feces. Metabolism of eprinomectin in cattle and rats were qualitalively similar. Therefore the Sprangue-Dawley VAF rat is a good laboratory animal model to evaluate the human food toxicology safety of eprinomectin.

    Hypoxia-actived Prodrugs of Diffusible Cytotoxins (HPDCs)——Synthesis and Characterization of Co(Ⅲ) Mustard Complexes and Cytotoxicity in Vitro
    YANJun, HUANG Hong-Jun, YANG Pin, CUI Hai-Ping
    2000, 21(S1):  147-147. 
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    Hypoxic cells are present in most solid tumors of the men and animals, which occur in the interface between the well-oxygenated tissue and the necrotic regions. Hypoxia can be a direct cause of therapeutic resistance because some drugs and radiation require oxygen to be maximally cytotoxic. Cellular metabolism is altered under hypoxic conditions. In addition there is evidence that Hypoxia can enhance genetic instability in tumor cells thus allowing more rapid development of drug resistance cells.

    Cathepsin K Inhibitors for Treatment of Osteoporosis
    TIAN Zong-Qiang, PALMER James T., BUYSSE Ann, VENKATRAMAN Shankar, MENDONCA Rohan, MCGRATH Mary E.
    2000, 21(S1):  148-148. 
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    Cysteine Proteases have been implicated in a broad spectrum of disease processes including cancer, arthritis, and viral and parasitie diseases[1]. Cathepsin K, a cysteine protease of the papain superfamily, is selectively expressed in osteoclasts and has been implicated in the process of bone resouption[2]. It is therefore considered a promising therapeutic target for treating diseases charccterized by excessive bone loss, such as osteoporosis[3]. Several chemotypes of cathepsin K inhibitors will be reviewed. The design and synthesis of potent inhibitors will also be discussed.

    Chemical Constituents from Notoseris Species
    YE Xiao-Xia, WANG Ming-Kui, GUAN Jia-Fa, HUANG Ke-Xin, DING Li-Sheng
    2000, 21(S1):  149-149. 
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    The genus Notoseris (Asteraceae) comprising of 14 species is endemic in China[1]. Two new sesquiterpene lactones,notoserolides A and B,along with 12 known compounds were isolated from the aerial parts of N. Porphyrolepis[2], but nothing is known about secondary metabolites of other N species.

    Studies on the Interaction of Ru(Ⅱ) Polypyridyl Mixed-ligand Complexes and DNA by Viscosity Measurement
    HE Xiao-Feng, JI Liang-Nian
    2000, 21(S1):  150-150. 
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    The interaction of transition metal polypyridyl coordination compounds with DNA has been extensively studied in the past few years[1]. Li the case of double stranded DNA, some coordination compounds may bind in the major groove with one ligand inserting between two base pairs DNA. The viscosity studies provide a strong argument for intercalation[2].

    Effects of the Oxovanadium Compounds on Human Erythrocytes
    YANG Xiao-Gai, WANG Kui
    2000, 21(S1):  151-151. 
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    In recent years, vanadium compounds have attracted the interest of many researchers due to their potential use in diabetes treatment. In order to improve their therapeutic effect, quite a lot of vanadium compounds were synthesized and screened. The structure-activity relationship has been explored. However, the actual therapeutic effect is not only dependent on the pharmacological action, but also on whether an effective level could be established in the target site. In the present work, the bioavailability and the toxicity of the different oxovanadium confounds were studied using human erythrocytes as a model system.

    The Effects of Citrato Molybdate on the Growth, Rate of Azotobacter Vinelandii
    QIU Xue-Hui, DONG En-Heng, ZHOU Zhao-Hui, LONG Ming-Nan, ZHANG Feng-Zhang, XU Liang-Shu, WAN Hui-Lin
    2000, 21(S1):  152-152. 
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    An iron-molybdenum cofactor (FeMoco or M-cluster) of nitrogenase is believed to be the active center for the N2-binding and reduction. Recent X-ray crystal structure of MoFe-protein revealed the FeMoco as FeS3Fe3(S)3Fe3S3Mo(R-homocitrate) cluster and the biosynthesis of FeMoco requires at least six nif gene products. FeMoco should be assembled firstly and then inserted into the FeMoco-deficient dinitrogenase. It has been known that the NifB-co, the product of nifB, is an iron and sulfur-containing precursor of FeMoco. However, how the molybdenum and homocitrate are assembled into molybdenum free NifB-co remains unknown.

    Synthesis and Theoretical Studies of Phosphoryl Amino Acid Analogue
    TAN Bo, JU Yong, WANG Yu, QIN Dong-Yan, ZHAO Yu-Fen
    2000, 21(S1):  153-153. 
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    Phosphoryl amino acids and their analogues are continuing to be increasingly important as potential enzyme inhibitors, mechanistic probes for proteases[1,2]. Previously, a series of investigations on the structure-reactivity relationship about phosphoryl amino acids 1 had been carried out, the results showed that the co-participation of phosphoryl group, carboxyl group and residues of amino acids were essential and their biomimic reaction mechanisms were commonly through a penta-coordinate intramolecular mixed carboxylic-phosphoric anhydride intermediates[3].

    Study on the Interaction of a New Antitumor Drug with DNA
    WANG Xue-Mei, LI Yao, GONG Sheng-Jin
    2000, 21(S1):  154-154. 
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    Binding studies of small molecules with nucleic acids can not only provide new insight into biologically important non-covalent binding mechanisms but also afford a molecular basis to understand the interaction and sequence recognition by promising drugs targeted to DNA. A series of the investigation of the binding of some natural antibiotics, metal complexes and other heterocyclic cations is valuable for the rational design of new antiviral and antitumor agents for clinical use.

    The Effect of Chemical Structure on the DNA Binding Behavior of Tricyclic Heteroaromatic Ligands
    WANG Xue-Mei, LI Yao, JIANG Xian-Hun
    2000, 21(S1):  155-155. 
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    It is well-known that small organic ligands can bind to the double-stranded nucleic acids by three modes, i.e.s grooving binding, intercalation, and electrostatic binding. Usually, intercalation of the ligands into the double helix involves the insertion of a planar atomatic cation into base stack of the helix, while groove binding of small molecules is pertaining to the docking of thin ribbon-like molecules in the minor groove of the helix. In both cases, electrostatic and hydrophobic interactions can afford additional stabilization for the binding.

    Nanomaterial Application in DNA Binding Studies
    WANG Xue-Mei, LIYao, ZHANG Yu
    2000, 21(S1):  156-156. 
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    Nanomaterials and nanotechnological devices will be certain to provide critically important applications in various fields of science and engineering due to the unique surface properties and special behavior of nanostructures typically with high ratios of surface area to volume. With a view to explore possibilities for the potential applications of some nanoscale particles, which show different behavior from that of ordinary materials, in the area of biomolecular recognition, we have tested the DNA binding properties of some ligands such as methylene green (MG), etc, in different buffer solutions of Au colloid.

    A Novel Iron(Ⅲ)-nickel(Ⅱ) Heterodinuclear Complex as Structural Core Models for Dimetalloenzymes
    YIN Li-Hua, CHENG Peng, YAN Shi-Ping
    2000, 21(S1):  157-157. 
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    The study of heterodimetallic complexes is interesting in regard to their potential in modeling the structures and reactivities of metalloenzymes containing two distinct metal ions (such as[NiFe] hydrogenase and purple acid phosphatase) in their active sites. However, the preparation of mixed-metal complexes is often a considerable challenge.

    New Tetraazamacrocyclic Ligand with Neutral Pendent Groups 1,4,7,10-tetrakis (2-cyanoethyl)-l,4,7,10-tetraazacyclododecane (L) and Its Cobalt (Ⅱ), Nickel (Ⅱ) and Copper (Ⅱ) Complexes:Synthesis, Structural Characterization and Antitumor Activities
    KONG De-Yuan, XIE Yu-Yuan
    2000, 21(S1):  158-158. 
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    A new tetraazamacrocyclic ligand (L) with four neutral 2-cyanoethyl pendent groups and its divalent transition-metal complexes:[Co(L)(NO3)]NO3·H2O (1),[Ni(L)(NO3)]NO3·3H2O (2) and[Cu(L)(H2O)](NO3)2 (3) have been synthesized. The crystal structures of (1) and (3) have been determined by X-ray analysis. In complex (1) the cobalt atom is coordinated by four nitrogen atoms and two oxygen atoms of a nitrate anion, which define a distorted octahedron. The other nitrate ion lies in the lattice as a counter ion.

    Synthesis, Structural Characterization and Potentiometric Studies of Divalent Metal Complexes with Octadentate Tetraazamacrocyclic Ligand and Their DNA Cleavage Ability
    KONG De-Yuan, XIE Yu-Yuan
    2000, 21(S1):  159-159. 
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    Four new metal complexes with octadentate macrocyclic ligand[L=1,4,7,10-tetrakis(2-carbamoylethyl)-1,4,7, 10-tetraazacyclododecane] were synthesized and characterized by elemental analyses, IR and MS. These complexes have the general formula:M(L)(NO3)2·nH2O[M=Co(1), Ni(2), n=2; M=Cu(3), Zn(4), n=l]. The structures of complexes:(1), (2) and (3) have been determined by X-ray diffraction.[Co(L)(NO3)](NO3)]·2H2O (1) crystallizes in the triclinic space group P 1. The refinement converges with R=0.045 and Rw=0.057 for 3233 reflections with (I>2.5σ(I)). The Co has a octahedral geometry, was coordinated with four amine nitrogen atoms of macrocyclic ligand and two or one acylate oxygen atoms derived from amide pendant groups.[Ni(L)(NO3)](NO3)·2H2O (2) crystallizes in the monoclinic space group C2/c.

    Single Molecule Force Spectroscopy on Proteins by AFM——Nanomechanics Meets Molecular Biology
    LI Hong-Rin, OBERHAUSER A., MARSZALEK P., CARRION M., FERNANDEZ J.
    2000, 21(S1):  160-160. 
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    Tandem modular proteins underlie the elasticity of natural adhesives, cell adhesion proteins, and muscle proteins. The fundamental unit of elastic proteins is their individually folded modules. Here, we combine single molecule force spectroscopy and molecular biology to investigate the nanomechanical properties of these modular proteins. Our experiments reveal the mechanical design of modular proteins, and opens the way for the engineering of elastic proteins with defined and tunable mechanical properties, which can be used in tissue and fiber engineering.

    Structural Characterization and Antioxidative Activity of Polysaccharide from Adenophora Potaninii
    CHEN Qian, CHEN Xiao-Ming, LIN Xin, LI Xin-Fang, LIZhi-Xiao
    2000, 21(S1):  161-161. 
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    The bioactivity of polysaccharides extracted from Adenophora Potaninii have been investigated[1,2], but its chemical structure has not been reported. We now describe the structure and the antioxidation activity of a water soluble polysaccharide, APl, which was extracted from the roots of Adenophora Potaninii by boiling water. The crude polysaccharide was isolated and purified by DEAE-cellulose and Sephadex G-200 column, thus, AP1 white powders, was obtained.

    Electrochemical Behavior from Pig Spleen Ferritin and Bacterial Ferritin of Azotobacter vinelandii
    HUANG He-Qing, LIN Qing-Mei, WANG San-Ying, LUO Da-Ming
    2000, 21(S1):  162-162. 
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    Being electrochemical studies, a rate of the core potential shifting to negative as a form of -205mV+(-115mV/pH) from horse spleen ferritin (HSF) has been measured by microcoulometry in the presence of mediator such as methyl viologen[1]. It was well indicated that the mediator played an important role in transferring the electrons between the ferritin and the electrode. However, using cyclic voltammetry of pulse polarography, HSF appeared appreciable currentless at the mercury electrode at scan rate 5 mV.s-1, moreover, and its mineral core isolated from protein shell showed the reductive current[2]. Evidently, these results was known that the ferritin shell be no a redox protein due to it no exhibited the current at the electrode at low potential.

    Three Dimensional Quantitative Structure Activity Relationship of Hept Analogs as HIV-1 Reverse Transcriptase Inhibitors
    MENG Ge, CHEN Fen-Er
    2000, 21(S1):  163-163. 
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    The discovery of the crystal structure of HIV-1 reverse transcriptase (RT) provides a new clear target for designing anti HIV drugs with less side effects. 1-[(2-hydroxyethoxy)methyl]-6-(phenylthio)-thymine (HEPT)and its analogs are selective HIV-RT linhibitors. Chemists carried out extensive studies on the modification of HEPT and provided a lot of data on biological activity of its analogs. In this paper 35 HIV-1RT inhibitors were selected from literature[1] and investigated by CoMFA method[2] for QSAR study.

    I-123 Labeled IVFRU-A Promising Noninvasive Nuclear Gene Imaging Probe
    PAN Dong-Feng, AHMED Hossam, WANG Guo-Quan, KALLMES David
    2000, 21(S1):  164-164. 
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    The potential of gene therapy as a clinical treatment modality for a variety of disorders has attracted considerable attention in recent years. Clinical trials investigating the benefits of gene transfer have proliferated rapidly. In particular, the Herpes Simplex Virus Type 1 Thymidine Kinase (HSV1-TK) gene as suicide gene have occupied a central role in this area of research.

    Microcalorimetric Study of Antibacterial Activity of Salicylaldehyde Glucosamine Copper(Ⅱ) Complex on E.coli
    HUANG Zai-Yin, TAN Xue-Cai, LEI Fu-Hou
    2000, 21(S1):  165-165. 
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    Since Schiff base and its metal complexes are of antibacterial and anticancer bioactivity, it has been a research subject of much interest. It is reported that Cu(Ⅱ)-SG could inhibite the synthesis of O2- markedly and could also combine with the salmn sperm DNA. The paper repored that by using microcalorimetric method The growth meloabolism of E.coli at different temperature and reacted upon by Cu(Ⅱ)-SG. The power-time curves of E.coli reacted with Cu(Ⅲ)-SG at different temperature has been determined by LKB2277 Microcalorimetric Monitor and the multiplication rate constant k, generation time G,bacterial growth inhibition ratio I,total thermogenetic quantity Q, the heat quantity of a single bacterium. Q0 and the heat quantity of a single bacterium per minute Q0 have also been calculated. On the basis of k~T data, the formula Lnk~1/T has graphically obtained and activation energy Ea and pre-exponential factor A have been calculated. According to the parameters of the growth metabolism of E.coli,some linear relationships have been derived. The paper provides a discussion about the growth metabolism of E.coli reacted upon by Cu(Ⅱ)-SG at different temperature, and it is found that、and tr can be used to characterize bacterial growth metabolism and the antibacterial activity of Cu(Ⅱ)-SG at different temperature.

    Imaging Cholesterol Vesicles Aggregation in Bile Models
    LI Guang-Ming, ZHANG Ying, GAN Li-Hua, WANG Pei-Jiao, CHEN Long-Wu
    2000, 21(S1):  166-166. 
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    Investigation of aggregation of cholesterol vesicles is essential for the understanding of gallstones prior to the appearance of cholesterol monohydrate crystals. In this article, according to existing data based on various microscopic techniques and present data on various microstructural pathways leading to cholesterol crystal formation in bile models, we considered the bile models composed of cholesterol, bile salts and lecithin and distilled water and employed light polarization microscopy and microelectrophoresis apparatus. Concentrated isotropic solutions of bile models were diluted to induce cholesterol supersaturation and start an evolution of microstructures, leading to cholesterol crystallization.

    The Extraction of Polysacchariddes from Flammulina Velutipes under Microwave Irradiation
    XIONG Jian, ZHANG Wen-Chao, LI Bing, CAI Miao-Yan, LI Lin, MO Li-Ping
    2000, 21(S1):  167-167. 
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    Flammulina Veluntipes (Curt. ExFr.) Sing contains lots of bioactive components, such as equal amylose, mixed amylose, sugar albumen, albumen polysaccharide, proflin and so on, that all have effects of anticancer and restrain tumour. The PA3DE and PA5DE are made of D-glucose, D-mannose and other saccharides. The Structures and bioactivitis of the PA3DE and PA5DE extracting from Flammulina Veluntipes (Curt. ExFr.) Sing have been reported[1]. But the extraction rate by hot water and alkali solution is much low.

    Studies on the Thermochemical Equations of Escherichia Coli Aerobic Growth Metabolism
    LIU Yi, SUN Da-Yuan, QU Song-Sheng
    2000, 21(S1):  168-168. 
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    An LKB-2277 Bioactivity Monitor was used to determine thermogenic curve of the growth metabolism of Escherichia coli at 37℃. The experimental results indicate that the relation between cell concentration and power output can be characterized by the equations:C=kP+a,dC/dP0=KC1 where P is the power output (μW), C is cell concentration (mg·mL-1),P0 is the power output produced by the metabolism of one unit of cell (P0=P/0.6 C),k, a and K are constants which depend on the culture condition and physiological state of the cells.

    Synthesis, Crystal Structure and Electrochemistry Property of 5,5'-dimethyl-2,2'-bipyridine Silver(Ⅰ) Complexes
    TONG Ye-Xiang, ZHU Hai-Liang
    2000, 21(S1):  169-169. 
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    The synthesis, crystal structures and electrochemistry of two easily soluble silver(Ⅰ) complexes[Ag(dmbpy)(NO3)] 1 and[Ag(dmbpy)](ClO4) 2,where dmbpy is 5,5'-dimethyl-2,2'-bipyridine, have been studied. Single-crystal X-ray diffraction reveals each silver(Ⅰ) atom in 1 is in a Y-shape coordination geometry with (the average Ag-N=2.278 Å) two N atoms from a dmbpy and an O atom (AgO=2.218 Å) from the monodentate nitrate. Each silver(Ⅰ) atom in 2 is three-coordinated by three N atoms, two of which are from a dmbpy, and one from the acetonitrile. 1 and 2 underwent an overall cyclic voltammogram process in acetonitrile and both complexes are stabilized by dmbpy in acetonitrile.

    Properties of Intermolecular Multiple Quantum Coherences and their Application in Magnetic Resonance Imaging
    CHEN Zhong, LIN Guo-Xing, CHEN Zhi-Wei, ZHONG Jian-Hui
    2000, 21(S1):  170-170. 
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    Over the last few years, intermolecular multiple-quantum coherences (MQCs) have attracted theoretical attention and also caused controversies in the NMR community[1-3]. Although there are still some theoretical issues which remain to be addressed, intermolecular dipolar interaction effects have lost much of their mystical character and are becoming useful tools in NMR spectroscopy and MR imaging[2-6]; Recently, we have successfully obtained human tissue double quantum coherence images in 1.5 T scanned[4,5] and 5-th order MQC images of water phantom on a 9.4 T system[6].

    Chemical Constituents of Three Species of Rubus
    WANG Ming-Kui, LIANG Jian, ZHAO Wei-Quan, LIU Rong, DING Li-Sheng
    2000, 21(S1):  171-171. 
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    There are about 700 species of Rubus widely spreading in the world, about 194 species in our country11. Their traditional use is for bums. There will be no scar on the skin after recovery. Our research indicated the predominant constituents were triterpenoids and tannins. The primary activity assay revealed that the EtOAc extracts had anti-bacteria and anti-fungi activity. We now report the triterpenoids from these three plants.

    Triterpenoids from Clematoclethra Scandens
    ZHANG Xiao-Rong, DING Li-Sheng, PENG Shu-Lin, WANG Ming-Kui
    2000, 21(S1):  172-172. 
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    Clematoclethra scandens (Franch.) Maxim., the only species in the endemic genus of Clematoclethra, which is used to treat detoxication, promote blood circulation and remove blood stasis[1]. Literature survey failed to show any report on its chemical constituents. During the course on a systematic investigation of the biologically active constituents from the endemic plant of western China, we have initiated chemical investigation on the whole plants of C. scandens and isolated eight known compounds from the extract of petroleum ether and EtOAc[2].

    Steroidal Saponins from Diuranthera Inarticulata
    YANG Wei-Li, TIAN Jun, ZHANG Qiang, PENG Shu-Lin, DING Li-Sheng
    2000, 21(S1):  173-173. 
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    From the methanolic extract of the whole plant of Diuranthera, inarticulata Wang et K. Y. Lang. (Liliaceae), which is endemic in the southwest of China[1], four new steroidal saponins, diuranthosides D-G, together with diuranthosides A and B and chloromaloside A, which were isolated from the roots of D. Major[2], were isolated.

    Interaction Studies Between Peroxovanadium Complexes and Model Peptide in Active Center of Tyrosine Phosphatase
    YE Jian-Liang, ZHOU Xing-Wang, CHEN Zhi-Wei, CHEN Zhong, HUANG Pei-Qiang
    2000, 21(S1):  174-174. 
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    Peroxovanadium(pV) complexes are potent protein tyrosine phosphatase inhibitors and possibly could be developed into a new kind of oral drugs for treatment of diabetes[1,2]. They have been paid considerable attention nowadays. Their action mechanism of insulin-mimetic effects involved in irreversibly oxidizing the catalytic cysteine of the enzyme according to the latest evidence[3]. However, little was studied on the structure-function relationship of pV complexes until our latest paper[4] in which we suggested that it related to the interaction between pV and functional groups in active center of tyrosine phosphatase except for their oxidizing ability. In order to convince our assumption, histidine and glutathione with model functional groins of imidazole and sulfhydryl residue in the active domain of target enzyme[5] were selected as study object of interaction with pV complexes.

    Study on the Interaction of Adriamycin to DNA
    LI Wen-You, XU Jin-Gou
    2000, 21(S1):  175-175. 
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    There has been considerable interest in understanding those factors that determine affinity and selectivity in binding of small molecules to DNA. These binding studies were driven partly by the need to understand the mechanism of anticancer drug action at the molecular level. The DNA binding studies with drugs have also provided a molecular basis to understand the binding and DNA sequence recognition by proteins.

    Antioxidant Activties of Stable Nitroxyl Radicals in Oil
    TIAN Xuan, WANG Hong, SUN Bin
    2000, 21(S1):  176-176. 
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    The nitroxides belong to stable free radicals which are widely used for spin labeling in ESR technique. Recently studies showed that nitroxide stable radicals demonstrate effective antioxidative activity in various biological systems ranging from molecular, cellular and laboratory animal level[l]. But up to now there isn't reported about antioxidant activities on oil of nitroxides. Because antioxidants on oil play a very important role in the food industry[2], therefore we want to utilize nitroxides as more effective antioxidants in the food industry.

    Effects of Heavy Lanthanide Gd3+ on the Growth of Escherichia Coli by Microcalorimetry
    ZHAO Ru-Ming, LIU Yi, XIE Zhi-Xiong, SHEN Ping, QU Song-Sheng
    2000, 21(S1):  177-177. 
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    The Chinese mainland abounds in rare-earth resources. In the recent years, the rare-earth compounds in soluble form are dispersed annually over agriculture land as fertilizer components to increase crop yield, since they can stimulate the growth and development of some plants. In such cases, there were many reports on their biological effects on plants, on the contrast, there are few reports on their effects on microorganisms.

    Syntheses and Properties of Tripicolinatechromium (Ⅲ)
    ZHOU Bao-Xue, ZHOU Ding
    2000, 21(S1):  178-178. 
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    Chromium (Ⅲ) has been implicated as glucose tolerance factor (GTF) in the maintenance of normal lipid and carbohydrate metabolism[1]. Several organic chromium (Ⅲ) complexes containing nicotinate, amino acids ligand which have much higher biological activity than chromic chloride have been synthesized and extensively studied[2]. Tripicolinatechromium (Ⅲ) as a new human chromium(Ⅲ) nutritional supplement was shown to reduce the symptoms of diabetes, hyperglycemia and cholesterol significantly[3]. Although the crystal structure and NMR spectrum of tripicolinatechromium (Ⅲ) was studied previously[4,5], Its properties have only received little attention. In this paper, we report the studies of syntheses and properties of tripicolinatechromium(Ⅲ).

    Transfer Gibbs Energies of[Cr(Salen)(H2O)2]BPh4 From Water to Straight-chain Alkanol
    CAO Li-Xin, ZHOU Ban-Xne
    2000, 21(S1):  179-179. 
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    Chromium(Ⅲ) is one essential nutrient that has been implicated as glucose tolerant factor(GTF) in the maintenance of normal carbohydrate and lipid metabolism. Schiff base complexes of chromium (Ⅲ) such as N,N' -ethylenebis (Salicylideneiminato) diaquochromium (Ⅲ) chloride[Cr(Salen)(H2O)2]Cl as a new kind of GTP model was shown to reduce the symptoms of diabetes significantly, hyperglycemia and cholesterol in diabetic rates[l]. After studied the decomposition and characterization of[Cr(Salen)(H2O)2]Cl[2], a new confound of[Cr(Salen)(H2O)2]BPh4 is prepared and its transfer Gibbs energies(Δtr Go) from water to strait-chain Alkanols is studied in order to understand the thermodynamic properties of[Cr(Salen)(H2O)2]+ in different solvents.

    A Ferritin Reactor for Entrapping Various Heavy Metal Ions in Flowing Seawater
    HUANG He-Qing, KONG Bo, LIN Qing-Mei, XIAO Zhi-Qun
    2000, 21(S1):  180-180. 
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    Recent studies showed that the ferritins had three tunnels across the protein shell with 0.7~0.9 nm diameter for iron metabolism[1-2]. However, very little was known the mechanism(s) that the ferritin reactor entrapped various heavy metal ions (M2+) and other small organic molecules in the flowing seawater directly.

    Depurating Polluted Water in Fishpond via Photo Synthetic Bacteria
    MENG Xiao-Hong, GUO Yan-Sheng, LIU Ke
    2000, 21(S1):  181-181. 
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    The photosynthesis prokaryotes, collectively known as photo synthetic bacteria (PSB), are recognized as having a remarkable ability to degrade the organic substances in the sewage water even with high concentration. In this paper, the PSB used for depurating the polluted wafer in the fishpond is investigated.

    Analysis of the Surface Water Pollution in Xining City in 1998
    MENG Xiao-Hong, LI Yan-Ping, WU Wan'e, WANG Xi-Mei
    2000, 21(S1):  182-182. 
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    The pollution features and causes, and the current pollution state in Xining reach, Huangshui River are exploited in this paper based on the corresponding water quality data monitored in 1998. It is illustrated that the main pollutants are of organic nature, including the Volatile phenol, BOD5, P.P Index, suspended materials and the NO2--N, and the pollution appears more serious during the low level water season.

    The Electrode Behavior and the Storing Capacity from Liver Ferritin of Dasynatis Akajei
    HUANG He-Qing, LIN Qing-Mei, KONG Bo
    2000, 21(S1):  183-183. 
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    Ferritin, a metallic protein, is a special biological large molecule that plays two central physiological functions in living cell simultaneously[1]. In addition, the ferritin is able to express two functions having activity of H2-uptake and exhibiting electrode behavior that picks the electrons up from a bare platinum electrode directly under anaerobic condition[2-3]. In this paper, a direct electrochemical technology under aerobic conditions is employed to study kinetics of iron release from liver ferritin of Dasyatis akajei (DALF). Using aerobic condition, an electron tunnel across the ferritin shell plays still a critical role in taking the electrons from a bare platinum electrode for iron release without any mediator aid. Moreover, using similar condition, two reduction potentials of the ferritin core with -135 mV and -416 mV vs. NHE are measured by the technology. Unlike other processes of iron release, a kinetic study for complete iron release is confirmed to show a triphasic behavior defined as zero-order reaction. DALF is known to heme bind to generate a hemeoprotein, named DALFh The heme function has been investigated to accelerate rate of iron release. Using similar studies, the kinetic datum indicates that the rate of iron release depends tightly on not only the reduction potential of the electrode, but also the regulation capacity of protein shell itself.

    Bioaccumulation of Mercury by Genetically Engineered Escherichia coli from Real Electrolytic Wastewater
    DENG Xu, LI Qing-Biao, SUN Dao-Hua, HUANG Yi-Li, CHEN Li, WILSON David-B
    2000, 21(S1):  184-184. 
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    Bioaccumulation performance of mercury from real electrolyte wastewater by genetically engineered E.coli JM109, which expresses a Hg2+ transport system and metallothionein was investigated. There were more than 10 components existing in the wastewater besides 2.58 mg/L mercury, and the pH of the wastewater was 9.6. The co-ions didn't decrease but somehow promoted mercury uptake rate of induced cells, while a 30% loss of the amount of mercury bioaccumulation was obtained in comparison with that from laboratory surrogate solution only containing mercury.

    Chemistry in Materials Sciences
    Solid Solution——Fact or Fiction?
    ZHOU Wu-Zong
    2000, 21(S1):  185-185. 
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    Over the years, man's knowledge of nature has extended endlessly from level of the naked eye into both the macrocosm and the microcosm. In the latter, modern science has not only determined the atomic arrangements of innumerable solid state materials, but also elucidated the electronic structure of molecules and atoms, and is now far advanced into the structures of the constituents of the atom itself. However, there are still some pieces of less developed territory left in the field of structural chemistry, one of them being the structures of so-called solid solutions.

    Chemical Reaction Engineering in Pharmaceutical Industry
    SUN Yong-Kui
    2000, 21(S1):  186-186. 
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    In this presentation, examples will be given to illustrate the role played by catalysis and reaction engineering in the development of robust and high yielding chemical processes in the pharmaceutical industry. These examples include heterogeneously-catalyzed Suzuki cross coupling and Heck coupling reaction[1], asymmetric hydrogenation of a-ketoesters over cinchona-modified Pt/alumina catalysts[2], kinetic influences on enantioselectivty in asymmetric hydrogenation[3,4], and applications of in-situ kinetic probes for kinetic and pathway analysis of catalytic reactions[5].

    Proteins in Countryclub-Like Jails:Encapsulation of Enzymes in Nanoporous Materials
    WEI Yen
    2000, 21(S1):  187-187. 
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    A popular method for enzyme immobilization is formation of covalent bonds between enzymes and a solid support, which often alters the enzymatic activities. Recently, various enzymes have been entrapped in inorganic oxides such as silica for biocatalysis and biosensor applications through conventional sol-gel process. However, because of the microporous nature (i.e. pore diameter of 1.5-2 nm or less) of conventional sol-gels, the activities of enzymes are hindered by low diffusion rates of substrate molecules and poor accessibility of enzymes inside the materials.

    Chemistry in Surface Science
    Mechanistic Study of Fullerene Formation by Traping Intermediates
    HUANG Rong-Bin, XIE Su-Yuan, DENG S.-L., ZHENG Lan-Sun
    2000, 21(S1):  188-188. 
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    After a flurry of research in the fullerene science, growth process and formation mechanism of the fullerenes has still remained as a mystery to chemists and physicists. Although various schemes have been put forward since then, none of them can sufficiently account for all experimental evidences about the fullerene formation[1].

    Chemistry in Energy Sciences
    From Zintl Ions in Polar Salts to Molecular Zintl Clusters in Solution
    DONG Zhen-Chao, ZENG Hui-Yi, CORBETT John D., NEJOH Hitoshi, GUO Guo-Cong, HUANG Jin-Shun
    2000, 21(S1):  189-189. 
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    Atomic-scale clusters are the ultimate nanoscale materials. These small clumps of matter contain from a few to hundreds of atoms, intermediate in size between molecules and solids, and are, in light of quantum effects, widely thought to be able to offer unique and valuable properties to the forthcoming molecular nanotechnology. While physicists prefer to use the "top-down" approach such as molecular beam epitaxy and lithographic techniques to fabricate nanostructures, chemists have the advantage to build up nanoparticles from well-defined small clusters in large amount (the so-called "bottom-up" approach). Examples of using Zintl phases for making nanoclusters, although rare, have been reported recently.

    Chemistry in Materials Sciences
    Strong Acidic and High Temperature Hydrothermally Stable Mesoporous Aluminosilicates with Well-ordered Hexagonal Structure
    XIAO Feng-Shou, ZHANG Zong-Tao, HAN Yu, QIU Shi-Lun
    2000, 21(S1):  190-190. 
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    Mesoporous molecular sieves such as hexagonally ordered MCM-41 have been attracted many researchers' attention since they are potentially used as versatile catalysts and catalyst supports for conversion of large molecules. However, as compared with those of zeolites, the acidity and hydrothermal stability of these mesostructured materials are relatively low, which strongly influence their practical applications in industrial catalytic reactions of petroleum. Despite several successful examples of preparation on the stabilization of aluminosilicate mesostructures at low temperature (in boiling water,100℃) including syntheses of materials with thick pore walls by triblock copolymers, removal of silanol groups by silylation, addition of salts effects,and post-treatments, their acidity and hydrothermal stability at high temperature (800℃) are still lower than those of microporous aluminosilicate zeolites.

    Interface Chemistry and Magnetism of 3d Metals and Alloys on GaAs
    JIN Xiao-Feng
    2000, 21(S1):  191-191. 
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    The 3d transition metals and alloys exist in a variety of crystallographic and magnetic phases. Thin-film growth of these materials on semiconductor substrates can drive the films into specific crystalline structures. These structures may be in a thermodynamically stable phase, a known high-pressure or high-temperature phase, or even a phase not previously observed. They greatly increase the variety of magnetic materials by essentially making "new" materials from "old" elements. In this talk I am going to focus the important role played by interface chemistry in such systems and its correlation to ultrathin film magnetism of 3d metals and alloys on GaAs(OOl).

    Photochromic Properties of New Dithienylethene Copolymer
    TU Hai-Yang, TIAN He
    2000, 21(S1):  192-192. 
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    Photochromic molecular switches can be important memory media for optical information processing and storage as long as their thermal stability and photo-fatigue resistance met certain criteria. Among many photochromic materials, heterocyclic diarylethenes have displayed desirable optical switching characteristics. Specifically, bisthienylethene (BTE)-based photochromic switches have demonstrated high sensitivity and rapid response as well as thermal- and photostability[1,2]. It has been shown that various BTEs can undergo ca.l0[4] cycles before significant evidence of fatigue[3]. It is important that molecules with otherwise improved switching characteristics retain this level of fatigue resistance. For example, the improved characteristics include that the absorption of close form of photochromic materials should be shifted to shorter wavelength region due that semiconductor laser shift to short wavelength are developing trend for high density information storage. Also, fatigue may be different in the solid state than in solution. In general, precedent photochromic polymers consisted of photochromic molecules either dispersed in a matrix or covalent grafted onto the polymer main chain.

    Oligomerization of Molybdenum Clusters via Multi-Functional Ligands
    YAO Yuan-Gen
    2000, 21(S1):  193-193. 
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    Trinuclear molybdenum clusters show diversity of reactivity towards transition metals and organic ligands. For example, different ligand-substitution and additive reactions can take place at the five coordination sites of Mo3S4(DTP)3(μ-L)(L')(Ⅰ). The bridging ligand μ-L, the terminal DTP'S and the loosely-coordinated ligand L'can be replaced by many carboxylic acids and polar solvents, respectively. By this way, many hetero-metallic cluster derivatives can be synthesized.

    Simulation of Nanomaterials
    CHEN Guan-Hua
    2000, 21(S1):  194-194. 
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    In this talk Ⅰ will discuss three developments required for simulating nano-scale devices, namely, (1) linear-scaling calculation for excited states, (2) beyond the Born-Oppenheimer approximation, and (3) quantum chemistry simulation of open systems. Linear-scaling localized-density-matrix (LDM) method has been developed for calculating accurately the excited state properties, for instance, absorption spectrum. It has been implemented with the PPP, CNDO/S, INDO/S, AM1 and PM3 semiempirical Hamiltonians, and applied to nano-sized PPV aggregates and carbon nanotubes. Nuclear dynamics has been simulated simultaneously with the electronic dynamics in the time domain, which is within the framework of the LDM method. Exchange of energy and electrons with the surrounding has been included as well, and interesting results on excited state relaxation and corresponding optical responses will be presented.

    Size-control Synthesis of Oxide Nanocrystals by Alcogel Chemistry under Normal Pressure
    XU Bo-Qing, WEI Jun-Mei, WANG Hai-Yan, ZHANG Fa-Zhi, YIN Shuan-Feng
    2000, 21(S1):  195-195. 
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    There is an urgent need,for chemists, to develop synthetic methods leading to large-scale formation of nanoparticles with selected sizes. Our group showed recently that a change of the conventional hydrogels of zirconyl hydroxide to its alcogels followed by nanocrystal formation under controlled atmospheres at elevated temperatures seems to be a simple and yet effective practice to the size control (8-30 nm) of nano-zirconia particles. This new approach is exploited here as a general method for the size-control synthesis of metal oxide nanocrystals.

    New Polyampholytes Based on Derivatized Polysaccharides:Synthesis,Aqueous Solution Properties and Applications
    ZHANG Li-Ming
    2000, 21(S1):  196-196. 
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    Synthetic polyampholytes combining both anionically and cationically charged species have been the focus of a number of studies due to their many potential applications[1].However, there are few works that studied the polyampholytes derived from modified natural polymers. Recent work in our group has dealt with the grafting of a cationic monomer or a cationic monomer coupled with a neutral or anionic monomer onto carboxymethyl cellulose (CMC) as well as the grafting of a zwitterionic monomer onto hydroxyethyl cellulose (HEC) by using various initiation systems[2-7]. Depending on the nature of used monomers, these modified polysaccharides can carry functional acidic and basic groups of different strengths.

    Synthesis of Carbon Nanotubes:A New Solid-state Approach
    XU Zhi-Ping, XU Rong, ZENG Hua-Chun
    2000, 21(S1):  197-197. 
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    In recent years, investigation on layered double hydroxide materials (LDHs, anionic clays) becomes an active field in layered materials research owing to their many important applications[1-7]. Among the LDHs, hydrotalcite-like compounds (HTlcs) have attracted great attention due to their synthetic flexibility in preparing catalyst and ceramic precursors, and in tailor-making adsorbents, medicine stabilizers, and ion exchangers[1,2]. In the structure of HTlcs, divalent and trivalent cations are located in the center of oxygen octahedron formed by six hydroxyl groups of the two-dimensional brucite-like sheets[1,2]. To balance the extra charges carried by trivalent cations, anions have to be intercalated into the inter-brucite-like-sheet space (interlayer space) during the synthesis, which leads to the formation of a sandwich-like structure alternatively stacked in vertical direction of the sheets (c-axis), forming a 3D structure.

    Encapsulation of Metalloporphyrins in Nanometer-sized Zeolites:Synthesis, Characterization and Catalysis
    NIU Guo-Xing, LI Xiao-Yuan
    2000, 21(S1):  198-198. 
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    The lasting extensive interest in zeolite molecular sieves, a class of nanoporous aluminosilicate oxidic crystals, lies in their three special properties:(a) the nanoscale porous cage that can serve as size- and/or shape-based host to recognize, select, and discriminate among the molecules, (b) the well-defined and controllable charge environment and charge strength inside pores that can facilitate or inhibit certain chemical processes, and (c) the well-organized pores/channels that can host the organization and assembly of molecules to display novel optical or electrochemical properties. Zeolitic materials possess yet another very important property, namely, their huge surface-to-volume ratio. Conventionally synthesized zeolites are quite large crystals with grain size at micrometer scale. This implies that the dominant portion of the "overall surface area" is attributable to the " interior surface" of nanopores/nanochannels instead of the "exterior surfaces" of the crystal powders. In many situations, this has limited the efficacy of zeolite materials, particularly in many catalysis-related applications. In order to improve the efficiency of catalysis of zeolite materials, it is often desirable to achieve a balanced ratio (~1) between interior-surface-area and exterior-surface-area, namely, to significantly reduce the size of zeolite crystals.

    Clatalytic Shilov Chemistry:Platinum(Ⅱ) Catalyzed Oxidation of Terminal Methyl Groups by Dioxygen
    SHEN Cheng-Yu, LIN Min-Ren, ASEN Yusman
    2000, 21(S1):  199-199. 
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    The selective catalytic oxidation of remote primary C-H bonds of organic substrates remains an intellectual and practical challenge. One example of metal-mediated functionalization (hydroxylation) of remote primary C-H bonds in involves the combination of PtCl42-/PtCl62- (the Shilov system). Despite its many attractive features, however, the Shilov system suffers from one crippling drawback:dixoygen cannot be used efficiently as the reoxidant. We have discovered that, with a proper cocatalyst at elevated temperature, Shilov chemistry can be made catalytic in dioxygen. A number of aliphatic acids were tested, and turnover numbers of un to 15/hour were observed.

    Prearation of Highly Ordered Mesoporous Silica Materials and Application as Enzeme Supports
    LI Bo, INAGAKI Shinji, TAKAHASHI Haruo
    2000, 21(S1):  200-200. 
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    An enzyme, horseradish peroxidase (HRP), was adsorbed in the manner of single immersion method on the silica mesoporous materials, FSM-16, MCM-41 and SBA-15 with various pore diameters from 27 to 92 and their enzymatic activity in an organic solvent and the thermal stability were studied. FSM-16 and MCM-41 showed larger amount of adsorption of HRP than SBA-15 or silica gel,when the pore sizes were larger than the spherical molecular diameter of HRP (ca 64×37). The increased enzyme adsorption capacity may be due to the surface characteristics of FSM-16 and MCM-41, which would be consistent with the observed larger adsorption capacity of cationic pigment compared with anionic pigment for these materials. The immobilized HRP on FSM-16 and MCM-41 with pore diameter above 50 showed the highest enzymatic activity in an organic toluene and thermal stability in aqueous solution at the temperature of 70℃. The immobilized enzymes on the other mesoporous materials including large or small pore sized FSM-16 showed lower enzymatic activity in an organic solvent and the thermal stability. Both surface character and size matching between pore sizes and the molecular diameters of HRP were important in achieving high enzymatic activity in organic solvent and high thermal stability.

    Synthesis of Nanometer-sized ZSM-5 Zeolite and Tts Use as Seeds for ZSM-5 Zeolite Membrane Preparation
    LIN Hai-Qiang, CHAO Zi-Sheng, CHEN Guo-Zhou, WAN Hui-Lin, TSAI Khi-Rui
    2000, 21(S1):  201-201. 
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    Nanometer-sized zeolite has been paid extensive attention, due to distinct advantages comparing with its commercially available micrometer-sized counterpart[1]. Moreover, it is most possibly to prepare a defect-free zeolite membrane, which emerges as one of hotspots in zeolite field, when nanometer-sized zeolite is involved in[2,3]. In the present work, we would both deal with the synthesis of nanometer-sized ZSM-5 and its using as seeds in the preparation of compact ZSM-5 membrane.

    Comparison of the Adsorption Behavior and Porosity of Clay and Various Porous Clays
    DAI Jing-Cao, XIAO Zi-Jing, WU Hang-Yu, HUANG Ji-Tai
    2000, 21(S1):  202-202. 
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    Recently, microporous materials,displaying zeolite-type properties, have attracted much interest[1]. As one of the most interesting synthetic molecular sieves[2],the porosity of porous clays plays a very important role on the application of microporous materials. Here we investigate the adsorption behavior and the pore size distributions of several porous clays materials by using N2 adsorption at low temperature (77 K),and discuss the influences of different crosslinking agents on resulting porosity of porous clays.

    TEM, XPS and ESR Studies of Sol-gel ZnO-SiO2 Nanocomposite and ZnO/SiO2 Prepared from Impregnation
    LIU Qing-Sheng, WANG Zhen-Lü, YU Jian-Feng, JIANG Yu-Zi, WANG Guo-Jia, WU Tong-Hao
    2000, 21(S1):  203-203. 
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    The ZnO-SiO2 nanocomposite was obtained using the sol-gel method[1] and the sample of ZnO/SiO2 was prepared by conventional impregnation way. A narrow size distributed ZnO nanoparticles had been observed on silica matrix through both methods by TEM. The particle size increased slightly with zinc oxide content and treatment temperature from the particles of an average value of ca. 3-5 nm for Zn10-T400 (the treatment 400℃ and the zinc oxide content 10 wt%) sample to an average value of ca. 6-8 nm in Zn10-T700 sample. Furthermore, the ZnO crystalline transition from monocrystal to polycrystalline phase had been observed with treatment from 400℃ to 700℃ in ZnO-SiO2 from the selected area diffraction patterns. XPS investigation indicated that the Zn 2p binding energy in samples of ZnO/SiO2 and ZnO-SiO2 increased greatly compared with zinc oxide, which suggested that strong interactions between nanometer-size ZnO and silica support were established. And it also suggested that the Si-O-H groups present in the surface of silica may be partially or totally substituted by Si-O-Zn bonds. Comparison of the ZnO-SiO2,the Zn 2p binding energy in the ZnO/SiO2 is lower, which implied that more Si-O-Zn groups existed on the former than the latter. The ESR results showed an interesting phenomena that a first-order standard differential ESR spectra (ge=2.062) appeared in all ZnO-SiO2 samples and no any signals in other samples. The ESR signal obtained may be due to O-, O2-, Zn+ or other ions. But the O- ion vacancy is unstable, and if the Zn+ and the O2- ions are the paramagnetic centers the g-factor should be equal to 2.0021[2] or 2.109[3], so the ESR signal from ZnO-SiO2 sample does not arise from the ions above. Perhaps it comes from Zn3+, because the g-factor is close to d9 and Zn 2p binding energy in ZnO-SiO2 is much higher than ZnO. The results showed that the interaction between microcrystlline ZnO and silica support in ZnO-SiO2 is stronger than in the ZnO/SiO2.

    Sol-gel Derived Silicate Phosphor Films
    LIN Jun, BAERNER K.
    2000, 21(S1):  204-204. 
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    Mn2+-doped Zn2SiO4 and Mg2Gd8(SiO4)6O2 phosphor films were deposited on silicon and quartz glass substrates by sol-gel process (dip-coating). The results of XRD and IR showed that the Zn2SiO4:Mn films remained amorphous below 700℃ and crystallized completely around 1000℃ From AFM studies, it was observed that the grains with 0.5-0.8 μm size packed closely in Zn2SiO4:Mn films, which were uniform and crack free. The luminescence properties of Zn2SiO4:Mn films were characterized by absorption, excitation and emission spectra as well as luminescence decay. These properties were, discussed in detail by a comparison with those of Mn2+ (and Pb2+)-doped Mg2Gd8(SiO4)6O2 phosphor films.

    New Compounds in Rare Earth-Trels-Tetrels Systems:Syntheses, Structures, Their Rich Chemistry and Physical Properties
    ZHAO Jing-Tai, SCHNELLE Walter, PASCHEN Silke, GRIN Yuri
    2000, 21(S1):  205-205. 
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    Intermetallic compounds constitute a very large fraction of inorganic compounds. Understanding these compounds with respect to their structures, chemical bonding, and physical properties is very important to fundamental materials science. The so-called Zintl phase (valence compound) subset of these has been of interest to many investigators for many years, and some understanding of this class of compounds has greatly broadened our views of chemical bonding[1-3].Some progress has been achieved for compounds between alkali metals and the triels Ga, In, Tl[4] Besides some structural reports[5-9], ternary systems of rare earth-trels-tetrels are especially lack of broad and further exploration. Here we report more than ten new compounds characterized in these systems. The as cast samples were synthesized by High Frequency melting method inside Ar-glovebox followed by annealing in silica tubes. Lattice parameter refinements were done from powder data using Si as an internal standard. The structures were determined either from single crystal or from powder XRD full profile refinements. The physical properties of the compounds will be discussed together with their structures and bonding features. The compounds show, depending on compositions, metallic Zintl phase, magnetic ordering, heavy Fermion behaviour or other phase transitions. The compounds have both rich structural chemistry and physical properties.

    Chemically Organizable Nanosized Materials Preparation and Applications
    LIU Zhong-Fan
    2000, 21(S1):  206-206. 
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    We are interested in fabricating well-organized assemblies of nanosized materials with wet chemical approaches for the purpose of investigating various interfacial and mesoscopic phenomena. The paper describes how to use self-assembling techniques to prepare assemblies of colloidal nanoparticles and single walled carbon nanotubes on solid surfaces. Gold nanocolloids are taken as the model system, including preparation of functionalized nanoparticles, assembling on tailored substrates, surface reorganization, and 1D, 0D controlled assembling with the aid of scanning probe lithography. The typical work we have been doing using these elaborated nanoparticle assemblies includes, the quantitative investigations of die electromagnetic coupling of particle-particle and particle-substrate in surface enhanced Raman scattering (SERS), the single electron tunneling in nanoparticle assemblies measured with scanning probe microscopy (SPM) technique, the atomic force microscopy (AFM) lithography using the surface-confined gold nanoparticles as mask.

    Syntheses of Nanocrystals Using Solid-state Double Decomposition Reactions at Room-temperature:CdS, ZnS and CaCO3
    LI Si-Dian, LI Sheng-Yun, ZHAO Xiu-Feng, HOU Yu-Cui, CHEN Juan, JIN Zhi-Hao
    2000, 21(S1):  207-207. 
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    Development of effective and reproducible approaches for preparing large amount of uniformly sized or narrowly size-distributed inorganic nanocrystals has remained as a great challenge in materials chemistry research in the past decade. Based upon Xiang and coworkers, work[1], in this paper we present a simple and effective approach directly utilizing solid-state double decomposition reactions at room temperature to produce nano-particles of CdS, ZnS and CaCO3 in the size range of 3-20 nm measured with x-ray diffraction. Transmission electron microscope (TEM) images of these nano-crystals confirm the existence of the aggregated "islands" of nano-crystals as the main body of the samples and the partially dispersed nano-particles in some areas. The processes of morphological variation and self-assembly of CdS nano-particles under electron beam bombardment are discussed as well.

    Chemistry in Energy Sciences
    Preparation of Gold Nanorods by Electrolysis:Electrochemical Reduction or Chemical Reduction?
    QI Hang, ZHENG Jie-Ru, ZHU Tao, LIU Zhong-Fan
    2000, 21(S1):  208-208. 
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    In the synthesis of nanosized materials, to control the particle shape is as important as to control its size, because the properties of the nanoparticles strongly depend on both size and shape. The properties of Au nanorods are different from its spherical counterparts in some ways due to the geometric anisotropy. For example, there are two surface plasmon resonance (SP) peaks in the UV-Vis region for Au nanorods, namely, the transverse (SPt) peak and the longitudinal (SP1) peak, respectively, while only one for spherical nanoparticles. Recently, Wang et al.[1,2] proposed an electrolysis-based method to produce Au nanorods with high throughput for the first time, and it was successfully adopted by El-Sayed et al.[3,4] in their studies on the optical properties and the thermal/laser induced shape transition of gold nanorods. However, the detailed growth mechanism of Au nanorods in such an approach remains untouched at present stage. To this point, only an ambiguous statement is available in Wang's paper[1,2] as that "the gold nanorods were converted from the bulk anode most likely at the interfacial region of the cathodic surface and within the electrolytic solution",it is still unclear whether the gold nanorods are formed electrochemically or chemically.

    Chemistry in Materials Sciences
    Aqueous Dispersions of Positively Charged Al/Mg Mixed Metal-Hydroxide Particles:Surface Chemistry and Rheological Properties
    SUN De-Jun, HOU Wan-Guo, ZHANG Chun-Guang
    2000, 21(S1):  209-209. 
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    The solids concentration, pH and NaCl were found to have a very significant effect on the rheological properties of aqueous dispersions of positively charged Al-Mg mixed metal hydroxide particles (Al-Mg MMH). At low solids concentrations the flow curves of the dispersions at natural pH followed the Newtonian model very well in the observed range of shear rate, while at high solids contents the dispersions developed a yielding type of response, with yield stress increasing rapidly as solids concentration increases. The variation in rheological properties with pH and NaCl contents correlated well with the change in surface properties of Al-Mg MMH particles. Al-Mg MMH dispersions with maximum yield stress occurred near the isoelectric point (IEP) where the Zeta potential (or electrophoretic mobility) is zero. At the IEP, the shear yield stress decreased monotonously in magnitude as a function of the increasing NaCl concentration, which is in contrast to the increment in the yield stress observed below the DEP at NaCl concentrations less than 0.1 mol dm-3. At low NaCl concentrations, significant shear yield stress differences exist at and below the IEP. By contrast, at high NaCl concentrations, almost identical shear yield stress versus NaCl results are obtained in both cases.

    Radiative and Nonradiative Lifetimes of Band Edge States and Deep Trap States of CdS Nanoparticles Determined by Time-correlated Single Photon Counting
    WU F., J. ZHANG Z., KHO Richard, MEHRA R. K., BECHTEL H., LOUNIS B., MOERNER W. E.
    2000, 21(S1):  210-210. 
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    Emission lifetimes of band edge and deep trap states of CdS nanoparticles with different surface capping were measured using time-resolved single-photon-counting[1]. For unpassivated nanoparticles with low fluorescence yield, the emission is dominated by deep trap states and the decay can be fit to a single exponential with a time constant of 5 ns that is independent of excitation intensity. For surface passivated nanoparticles with strong luminescence, the emission is dominated by band edge states and the decay is fit to a double exponential with time constants of a few ns and 50 ns. While the 50 ns decay is independent of excitation intensity, the fast component is strongly dependent on intensity. For the fast decay component, the amplitude decreases non-linearly and the time constant becomes longer (from 2.5 to 7.9 ns) as the intensity decrease. The results support the model of exciton-exciton annihilation[2] upon trap state saturation at high excitation intensities.

    Enantioselective Hydrogenation of Acetophenone over Cinchonidine-Stabilized and Supported Rhodium Clusters
    HUANG Yu-Lin, SUN Bin, LI Rui-Xiang, CHEN Hua, LI Xian-Jun, Albert S. C. CHAN
    2000, 21(S1):  211-211. 
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    Because of the importance of the chirality in chemicals in everyday, the synthesis of enantiomerically pure chiral compounds has become an important academic and commercial advantage. In asymmetric synthesis field, enantioselective catalysis has been the most challenging subject over the past decades. Among the numerous enantioselective heterogeneous catalysts, the rhodium is always an unsuccessful example under favorable reaction conditions with only 20%-30% enantiomeric excess (e.e.)[1].And almost all of papers about heterogeneous enantioselective catalysis have reported that rhodium is not suitable for heterogeneous enantioselective hydrogenation[1-3].

    Synthesis of SiC Fibers by Pyrolysis of Polycarbosilane Precursor Fibers Cured by γ-ray Irradiation
    XU Yun-Shu, FU Yi-Bei, HUA De-Geng, SONG Yong-Cai
    2000, 21(S1):  212-212. 
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    SiC ceramics fibers reinforced metal and ceramics composite materials have important application foreground in the area of space flight, inner wall of fusion reactor and new engine cylinders, The method[1] to fabricate SiC fibers by pyrolysis from organic polycarbosilane precursor fibers is an applicable technology, But oxygen must be used to cure the precursor fibers,and the residual SiO2 in the final SiC fibers seriously affect the high temperature resistant properties, In recent years, other curing methods[2] were explored to improve SiC fiber's properties, Previous results[3] showed that using electron beam to irradiate polycarbosilane fibers in various atmosphere.

    Novel One-dimensional Cyano-bridged Chain Molecular-based Magnet[Ln(DMF)4(H2O)2Mn(CN)6·H2O]n:Crystal Structure, Long-range Magnetic Ordering, High Tc and Strong Coercive Behavior
    YAN Bing, CHEN Zhi-Da, WANG Shi-Xi
    2000, 21(S1):  213-213. 
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    There has been great interest in the study of the magnetic properties of molecular-based compounds[1,2]. In the present work, we employed N,N-dimethylformide (DMF) as a hybrid ligand to synthesize a new family of cyano-bridged complexes contain rare earth and Manganese:[Ln(DMF)4(H2O)2Mn(CN)6·H2O]n (abbreviated as LnMn, Ln=Sm, Eu, Gd, Tb, Dy, Er) and the crystal data of former three complexes has been obtained, which display a remarkable variety of magnetochemical behavior and a rich structural chemistry.

    Toughening of Polymer-layered Silicate Nanocomposites
    HAN Yan-Chun, HARCUP J. A., YEE A. F.
    2000, 21(S1):  214-214. 
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    The field of organic-inorganic nanocomposites has recently attracted consideration attention due to their unexpected hybrid properties synergistically resulting from their parent components. One of the most promising organic-inorganic nanocomposites is polymer-layered silicate (PLS) nanocomposites. Some PLS nanocomposites exhibite dramatic increase in mechanical properties as well as gas barrier properties. But one pervasive problem with nylon-6 and epoxy nanocomposites for applications is their low fracture toughness. The objective of this research is to a method of toughening the nylon-6 and epoxy-silicate nanocmposites in order to have the proper toughness/stiffness balance of such nanocomposites.

    Synthesis and Electromagnetic Properties of Carbon Nanotubes
    LIANG Qi, YU Zuo-Long, DENG Long-Jiang
    2000, 21(S1):  215-215. 
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    Carbon nanotubes (CNTs) have attracted much interest of scientists for their extraordinary structure and properties. Recently much more efforts were devoted to synthesizing CNTs and understanding their insulating, semimetallic, or metallic behavior. In the present work, the perovskite oxides were used as catalyst precursor. We obtained bulk growth of high quality CNTs by catalytic decomposition of CH4 or CO using either fixed bed or fluidized bed reactor.

    Electrochemical Processing of Reaction-bonded Ceramic Composite Coatings
    WANG Z., SHEMILT J., XIAO P., LIN Chang-Jian
    2000, 21(S1):  216-216. 
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    Ceramic matrix composite coatings are currently of much interest for application in high-temperature and highly corrosive environments. Formation of ceramic coatings by electrochemical processing is a relatively new mean[1-2]. It presents several advantages over alternative coating techniques, the thickness and morphology of the deposit can be controlled by the electrochemical parameters, relatively uniform deposits are obtainable on complex shapes, the deposition rate is higher than that using most other methods and the equipment required is of low cost Recently we developed a novel fabrication technique for the production of ceramic/ceramic and ceramic/metal composite coatings by electrochemical processing[3]. The technique combined two electrochemical deposition methods, electrophoretic deposition (EPD) and electrolytic deposition (ELD), which can produce uniform composite layers of closely controlled thickness on both metallic and ceramic substrates at ambient temperature with inexpensive equipment. However, the main problem associated with electrochemical processing is the difficulty in sintering of the coatings. First, high temperature is required for sintering of the coatings. Secondly, the volume shrinkage of the coatings during sintering leads to the formation of cracks in coatings bonded to metal substrates. So a reaction forming technique, reaction bonding process, also has been developed to produce near net-shape ceramic coatings, which overcome problems caused by the shrinkage of ceramics during sintering.

    Kinetic Exponents of Grain Growth in Practical and Simulated ABO3 Ceramics
    XIONG Z. X., JI G. L., SHEN X. Y.
    2000, 21(S1):  217-217. 
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    It is now established that there is a strong correlation between the physical properties of ceramics and their microstructures, which result mainly from the grain growth process[1-3]. Therefore, the study of grain growth during the ceramic evolution is one of fundamental importance[4-6].

    Synthesis and Characterization of a New Class of Oligomers with Nanosized Interior Cavities
    ZHU Jin, GONG Bing
    2000, 21(S1):  218-218. 
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    Currently there is an intense interest in developing unnatural folding oligomers and polymers that may mimic or rival natural proteins[1]. Most of the efforts in this field have been focused on designing helical structures that mimic the natural α-helix[2], the best understood protein secondary structure.

    Template Synthesis of Nano-structured Materials for Electrochemical Applications
    YANG Y., ZHAO J., GAO Q. Y., LIN Zu-Geng
    2000, 21(S1):  219-219. 
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    As an important preparation method of nano-structured materials, template synthesis[1] attracted great interests in recent years. Different kinds of template such as anodic porous alumina, polymer and nano-channel glass templates have been widely studied. Compared with other templates, the size of holes in the porous alumina template can be easily controlled by properly adjusting the condition of anodization. In addition, Nano-structured material prepared from the template also provides an ideal system[2] to investigate the effects of size of materials toward electrode's performance. In this paper, various nano-structured materials such as spinel LiMn2O4 and carbon nanotubes by using porous alumina template have been prepared and characterized.

    Structure and Properties of Nanostructured Material of PtPbSb Surface Alloy Studied by Electrochemistry, XPS and STM
    CHEN Sheng-Pei, XIA Sheng-Qing, WANG Shui-Ju, CHEN Bao-Zhu, SUN Shi-Gang
    2000, 21(S1):  220-220. 
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    The preparation of electrocatalysts of high performance and low cost is one of the most important subjects in electrocatalysis. The use of glassy carbon (GC) as substrate has been investigated the most extensively[1]. In the present work, the nanostructured material of PtPbSb alloy supported on glassy carbon (PtPbSb/GC) was prepared by electrochemical co-deposition method. The structure and properties of these electrocatalysts were studied through techniques of cyclic voltammertry, X-ray photoelectron spectroscopy (XPS)pl and scanning tunneling microscopy (STM).

    Synthesis, Structure and Mechanism of a Series of Novel Nanocrystalline Rare Earth Orthovanadate Catalysts for Oxidative Dehydrogenation of Light Alkanes at Low Temperatures
    FANG Zhi-Min, ZHOU Zhao-Hui, DAI Shen-Jun, ZHANG Xiao-Feng, WENG Wei-Zheng, WAN Hui-Lin, TSAI Khi-Rui
    2000, 21(S1):  221-221. 
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    The oxidative dehydrogenation of light alkanes to light alkenes is one of the potentially important catalytic processes for the effective utilization of light alkanes. However, high temperatures were required to initiate the reactions on heterogeneous catalysts reported by other authors in the literature[1,2]. In recent years we reported a series of novel nanocrystalline rare earth orthovanadates synthesized by the peroxyl and nitrate methods for oxidative dehydrogenation of propane at low temperatures[3,4]. In this paper the synthesis of a series of novel nanocrystalline rare earth orthovanadates (LnVO4, Ln=Y, La, Ce, Pr, Nd, Sm Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb) by the citrate method is reported, together with the structural characterization and excellent performances of the catalysts for oxidative dehydrogenation of light alkanes.

    Self-aligned Submonolayer Cobalt Silicide Formation Studied by Variable Temperature Scanning Tunneling Microscopy in UHV System
    YE J. H., BAO G. W., WANG Yi, Pan J. S., LI S. F. Y.
    2000, 21(S1):  222-222. 
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    Epitaxial growth of defect free metal silicides with high thermal stability is important to ultra large scale integration devices (ULSI)[1]. Cobalt silicide has been used as an interconnect in CMOS devices due to its low resistivity and good thermal stability[2] and excellent lattice match between cobalt silicide and silicon[3,4]. In the present work, we have investigated epitaxial growth of ultra-thin cobalt layer (ca. 10 Å) by electron beam evaporation of cobalt on Si(111) (7×7) surface followed by thermal annealing up to 700℃ in UHV system. The morphologies and the surface structures of epitaxial silicide formation were investigated by using scanning tunneling microscopy (STM). Adlayer structures of Co silicide after annealing were observed to coexist as the closely and loosely packed clusters at 230℃ separated by a boundary. A new structure with ring-like clusters has (l×l) configuration with 3.5 A spacing between hollows of vicinal clusters at 400℃. Si-rich CoSi2 surfaces terminated by Si bilayers showed (2×2) structures after annealing at 480℃, in which Si-rich CoSi2 clusters were observed to be very mobile at room temperature. As the surface was annealed to above 500℃, The domain island became regular triangles, where atomic resolution of the l×l surface of CoSi2(111) were readily discernable. CoSi2(111) surface is suggested to be terminated by a Si-bilayer.

    Self-assembled Alkylation of Atomically Flat Hydrogen-terminated Silicon (111) Surface By Using Highly Polarized Fluoroalkylsilane
    LI Jing, YE J. H., LI S. F. Y., CHAI J. W.
    2000, 21(S1):  223-223. 
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    Hydrogen-terminated silicon surface is of technological importance to semiconductor processes such as pre-gate[1]. Re-contamination and re-oxidation on silicon surface become more stringent issues in order to meet the requirements in the process for producing reduced size IC chips. The modification of silicon surfaces by various strategies has attracted more attention in the past few years[2-4]. The frequently used techniques to attach functional groups to silicon surfaces are via chemical[2], photochemical[3] and electrochemical reactions[4]. Various ways to attach monlayers to silicon surfaces has been reported, including alkylation of silicon with alkenes, alkyenes, aldehydes, alcohols and Grigard reagents under photoactivated or catalytic reactions. Particularly, porous silicon prepared by chemical or electrochemical treatments has been extensively studied. Preparation of passivated layers on porous silicon surfaces has disadvantages that the silicon surfaces are damaged by reactive agents during the reaction or become porous for attachment of molecules. Recently, self-assembled monolayer of alcohols on porous silicon was reported at modest heating without the aid of catalyst or photoexcitation or potential[5]. In the paper, we report a novel method to attach highly polarized fluoroalkylsilane on atomically flat Si(111) surface at room temperature and to form a self-assembled monolayer to prevent the silicon surface from re-contamination and re-oxidation.

    Chemistry in Energy Sciences
    The Development and Industrial Application of New Type of High Mid-barrel Catalyst
    CHEN Song, GUAN Ming-Hua, LI Ting-Yu
    2000, 21(S1):  224-224. 
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    It is hard to choose zeolite type or amorphous type of hydrocracking catalyst in order to meet not only activity but also middle distillate selectivity. Here we introduce a new generation of hydrocracking catalyst that was developed for aiming at yielding more middle distillate with good activity.

    Chemistry in Materials Sciences
    Self-assembly of Tetranuclear Zinc(Ⅱ) Polymer with Mixed Ligands
    TAO Jun, TONG Ming-Liang, CHEN Xiao-Ming
    2000, 21(S1):  225-225. 
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    Polynuclear zinc(Ⅱ) complexes are of interest because of their intriguing structural and photoluminescent properties[1]. Zinc is easy to form a wide variety of clusters with a number of carboxylates (acetate, benzoate and pivalate), where combination of zinc and the appropiate carboxylic acid yields the oxo-centered cluster as a distinct and well-defined unit[2]. Working towards an extended network based on these clusters, we viewed their Zn-O-C motif as secondary building unit capable of assembly if an organic dicarboxylate and neutral ligands (4,4'-bpy) are used instead of a monocarboxylate. The rigid and divergent character of the additional linkers may allow the articulation of the clusters into a 2D or 3D framework. This simple and potentially universal design strategy is currently being pursued in the construction of coordination polymers with novel topologies and potentially exploitable functions[3,4].[Zn4(OH)2(fa)3(4,4'-bpy)2] (fa=fumarate, 4,4'-bpy=4,4'-bipyridine) was synthesized (Fig. 1) featuring "butterfly" Zn4(OH)2 clusters. All the Zn4(OH)2 clusters linked by chelating and bridging fumarate forms infinite 2D frameworks, which are further pillared by 4,4'-bpy molecules above and below such 2D frameworks to generate 3D infinite framework. Its building unit is shown in Fig. 2. This complex exhibits intense blue fluorescence at 532 nm in the solid state.

    Solvothermal Synthesis of Two Isomorphous Two-Dimensional Double Wave-like Vanadium, Coordination Polymers with Square Channels
    ZHANG Xian-Ming, TONG Ming-Liang, CHEN Xiao-Ming
    2000, 21(S1):  226-226. 
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    While organic-inorganic hybrid vanadium oxides, polyvanadate clusters and vanadium complexes have been extensively studied[1-3], the construction of microporous two-dimensional and three-dimensional vanadium coordination polymers by bridging organic ligands remains relatively unexplored[4], and hence further model complexes are required to understand the coordination nature of vanadium. We report here two isomorphous vanadium coordination polymers formulated as[VO(DBOD)2]X2(DBOD=l,4-diazoniabicyclo[2,2,2] octane-l,4-diacetate, X=Cl or Br). Crystal structural analysis shows that they are the first examples of non-cluster-type vanadium coordination polymer constructed from VO5 square-pyramidal units. DODB in μ2-niode along[110] and[1-10] directions links two adjacent two vanadium ions,Which resulting in double wave-like two-dimensional layers with 36-memered saddle-shaped rings (ca. 12.0×6.2 Å) As can be seen from the three-dimensional stacking array (Fig. 1), the adjacent two layers stack in a crossed laminating fashion giving rise to approximate square channels (ca. 6.2×6.2 Å) along c-axis direction.

    Coordination Molecular Architectures Based on Ag-HMT Nets
    CHEN Xiao-Ming, TONG Ming-Liang, ZHEN Shao-Liangg, ZHU Hai-Liang
    2000, 21(S1):  227-227. 
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    As self-assembly of the supramolecular architectures of coordination polymers is influenced by the many different factors, it is usually difficult to predict the structure of the product of self-assembly. As sequel work of our previous reports on coordination polymers with variable cavities or channels[1], we attempt to develop rational synthesis of desired molecular architectures and describe our design and construction of supramolecular architectures based on Ag-HMT (hmt=hexamethylenetetramine) nets. HMT is a potential tetradendate ligand, and Ag1 is flexible in coordination. We obtained a number of Ag-HMT nets in different dimension-alities, some of the Ag-HMT networks are stable, and may be further tailored to generate designed 3-D molecular architectures[2]. In particular, the lateral positions of the hexagonal 2-D[Ag(μ3-hmt)X] nets are occupied by small and labile ligands (X=NO3- or NO2-, which are align-ed in an alternative up/down fashion. The lateral ligands may be replaced by other functional ligands to provide new routes (see scheme below) in organising the 2-D layers into 3-D nets via linear dicarboxylates as molecular pillars or interlayer intercalation between the lateral aromatic mono-carboxylates, giving the designed 3-D molecular architectures with variable porous sizes. In this report, we will show a series of 3-D molecular architectures based on the hexagonal nets. On the other hand, when non-linear dicarboxylates are used, some other 3-D polymeric architectures can be isolated, including some of nanometer-sized channels. Study of gas absorption of the pore materials is under progress.

    Synthesis and Structures of Polynuclear Copper(Ⅱ)-lanthanide(Ⅲ) Complexes with Carboxylate-bridges or Imidazolemethanol
    YANG Yang-Yi, CHEN Xiao-Ming
    2000, 21(S1):  228-228. 
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    Polynuclear mixed-metal complexes are of current interest in chemistry and are of potential application in material science. We report herewith the synthesis and crystal structures of two dinuclear copper(Ⅱ)-lanthanide(Ⅲ) complexes containing pyridinioacetate (pyb, C5H5N+CH2CO2-) or N-Methyl-2-imizazolemethanol(imoh), namely[CuLa(pyb)5(H2O)(C1O4)5·2H2O (1) and[CuLa(imoh)2(NO3)3(H2O)2] (2). Complexes 1 features a dinuclear CuLa cation, in which the Cu and La atoms are bridged by a tetrakis(μ2-carboxylate) bridge, the Cu atom is coordinated in a square-pyramidal geometry with the apical position being occupied by an aqua ligan, the La atom is coordinated in a distorted square-antiprism. Complex 2 also features a dinuclear CuLa molecule, with Cu and La atoms are bridged by a di(μ2-imidazolemethanol) bridge, the Cu atom is coordinated in plane square geometry with two N and two O atoms from two imoh, besides the two O atoms from the di(μ2-imidazolemethanol) bridge, the La atom is complied by three chelating nitrates and two aqua ligans, to form bicapped square-antiprism geometry.

    Soluble Intermacromolecular Complexes Formed between Carboxymethyl Cellulose and Water-soluble Polymer with Complementary Structure
    ZHANG Li-Ming, HUANG Shao-Jie, HE Jian-Xun
    2000, 21(S1):  229-229. 
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    Homogenous complexation of water-soluble polymers with chemically complementary structures in aqueous media has recently attracted great interest[1]. It is known that such macromolecules in solution can interact with each other, resulting in excluded volumes and ordered structures through the formation of soluble intermacromolecular complexes[2]. Therefore, such systems may possess unique properties that are different from those of individual components and there are many potential applications.

    Studies on New Hydrophobically Modified Water-soluble Cellulosic Graft Terpolymers
    ZHANG Li-Ming, ZHANG Jian, LI Zhuo-Mei
    2000, 21(S1):  230-230. 
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    Hydrophobically modified water-soluble ion-containing cellulosic polymer possessing intra-or intermolecular modes of hydrophobic associations has been recently the object of our research[1-4]. Based on the preparation of the surface-active monomer, dimethyloctyl (2-methacryloxyethyl)ammonium bromide (DMOA), new cellulosic graft terpolymers (NCGT) have been synthesized by grafting acrylamide (AM) and DMOA onto carboxymethyl cellulose (CMC) using potassium persulfate and dimethylaminoethyl methacrylate as the initiating system, and characterized by FTIR, elementary analysis, titration and GPC. To obtain the optimum reaction conditions, the influence of the feed ratio and addition order of raw materials, the concentration of initiators, temperature and pH on the grafting have been investigated.

    Electroless Deposition of Polyaniline
    LIAO Chuan-Ping, SUN Shi-Gang, ZHOU Shao-Min, YAO Shi-Bing
    2000, 21(S1):  231-231. 
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    In electropolymerization, aniline is oxidized at the anode to form polyaniline (Pn) film, an important conductive polymer with high chemical stability[1].

    Light-induced ESR Studies of Electron Transfer Mechanism of Triazo Pigments
    WANG Guo-Ping, LEI Qun-Fang
    2000, 21(S1):  232-232. 
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    Triazo pigment is a new class of excellent organic photoconductive materials, which is synthesized with tertiary aromatic amines and different couplers. The tertiary aromatic amine is a typical electron donor[1]. After irradiation, the electron-donating ability of excited states becomes stronger than that of ground states, radical pair and radical ions are considered to be key intermediates. In the present work, the light-induced ESR spectra of 3-As-SG under different conditions are investigated. It is verified that an electron-transfer process occurred.

    Synthesis, Characterization and Self-assembly of Gold-coated Iron Nanoparticles
    LIN Jun, ZHOU Wei-Lie, CARPENTER E.-E., O'CONNOR Charles-J.
    2000, 21(S1):  233-233. 
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    Due to their small size (1-100 nm), nanoparticles exhibit novel materials properties that differ considerably from those of the bulk solid state. Especially in recent years, the interests in nanometer-scale magnetic particles are growing based on their potential application as high density magnetic storage media. A unique reverse micelle method has been developed to prepare gold-coated iron nanoparticles. XRD, UV/vis, TEM and magnetic measurements are used to characterize the nanocomposites. XRD only gives FCC paterns of gold for the obtained nanoparticles. There is a red shift and broadening of Au@Fe colloid relative to pure gold colloid in the absorption spectra. TEM results show that the average size of Au@Fe nanoparticle is about 10 nm. These nanoparticles self-assembled into wires in micron level under a 0.5 T magnetic field. Magnetic measurements show that the particles are superparamagnetic with a blocking temperature of 42 K. Coercivity of the obtained nanoparticles decreases with the measuring temperature, which are 730 Oe,320 Oe and 0 at 2 K, 10 K and 300 K, respectively.

    Synthesis of Hexagonally Mesostructured Array of Surfactant Micelles and 12-tungstophosphoric Heteropoly Anions
    XIN Jing, SUO Ji-Shuan, ZHANG Han-Peng, ZHANG Xiao-Ming
    2000, 21(S1):  234-234. 
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    Heteropoly tunstates, in particular Keggen ions, play an important role in the catalysis science.[1,2] Although they have mainly been used as a solid or in an aqueous solution so far, if mesostructured materials with Keggin ion frameworks could be synthesized, they would be expected to show novel functions in fields such as catalysis, electrochemistry, and host-guest chemistry.

    Synthesis and Crystal Structure of First Trinuclear Copper(Ⅰ) Complex with Coplanar Cu3O3 Core
    REN Yan-Ping, LONG La-Sheng
    2000, 21(S1):  235-235. 
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    Very recently, five-coordination copper(Ⅰ) complex with distorted square-pyramidal geometry,[CuL1(NCCH3)]+(L1=Dimethyl-2,4-bis(2-pyridinayl)-3,7-diazabicyc lo-[3.3.l]-nonane-9-on-l,5-dicarboxylate)[1], has been synthesized. X-ray structure shows that the rigid ligand L[1] is well suited for copper(Ⅱ) ion, and highly strained for copper(Ⅰ) ion. Those results indicate that the lack of Jahn-Teller effect of copper(Ⅰ) ion often decreases the stability of copper(Ⅰ) precursor complexes, and plays an important in the transportation or activation of dioxygen for copper-containing proteins[1].

    Synthesis of Mesoporous Molecular Sieves via a Novel Templating Scheme
    XIN Jing, SUO Ji-Shuan, ZHANG Xiao-Ming
    2000, 21(S1):  236-236. 
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    Since Mobil researchers reported the discovery of a new family of silica-based mesoporous molecular sieves (M41S) materials in 1992[1,2], there has been a growing interest in using these materials as heterogeneous catalysts, catalyst supports, and nanocomposite host materials for novel applications. All these applications have stimulated many researchers to synthesize mesoporous materials via different templating schemes or synthesis pathways. So far, ionic and neutral surfactant including neutral alkylamine[3], polyethlene oxide[4], genimi[5], and amphiphilic triblock copolymer[6] have been the most commonly used as templates for the directing the formation of mesoporous.

    Photocatalytic Oxidation of Methane over Water-preadsorbed Mesoporous Molecular Sieves Catalysts
    XIN Jing, CHEN Xi-Hui, SUO Ji-Shuan, ZHANG Xiao-Ming, LI Shu-Ben
    2000, 21(S1):  237-237. 
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    Although the photocatalytic direct conversion of methane into oxygen-containing organics over solid oxide semiconductors has been investigated for many years, few attempts to directly convert methane with high conversion and high selectivity have been successful[1-4].

    Internal Conversion with N,N-substituted 1-aminonaphthalenes:Photophysics and Applications
    SUN Xiang-Yin, WEN Zheng-Chang, JIANG Yun-Bao
    2000, 21(S1):  238-238. 
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    The solvent polarity dependence of the fluorescence quantum yield and lifetime of 1-dimethylaminonaphthalene (DMAN) was fund different from that of normal case in that the two parameters increase with increasing solvent polarity, in spite of the fact that the emissive state of DMAN was also of ICT character. Steady state and time-resolved fluorescence studies have currently indicated that a thermally activated internal conversion (IC) occurred with DMAN[1,2]. The IC was assumed to be the consequence, of the vibronic coupling of the emissive S1 state and S2 state with the activation energy of the IC process depending on the energy gap between S1 and S2 states. It was hence put, forward that with increasing solvent, polarity the energy of the S1 state would be lowered more than that of the S2 state, leading to higher energy gap between the S1 and S2 states and therefore suppressed IC. As a consequence, increased fluorescence quantum yield and lengthened lifetime were observed.

    Halfsandwich Transition Metal Complexes with 1,2-dichalcogenolate Carboranes
    JIN Guo-Xin
    2000, 21(S1):  239-239. 
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    Mononuclear halfsandwich transition metal complexes (Cp*M) are useful model compounds in which one hemisphere of the coordination shell is blocked by the voluminous Cp* ring. In the protected space below the Cp* ligand, one or two 1,2-dicarba-closo-dodecarborane-1,2-dichalcogenolate ligands can be accommodated, e.q. a mono-dichalcogenolate carborane halfsandwich iridium complexes Cp*Ir(E2C2B10H10)(E=S, Se)[l] and bis-dichalcogenolate carborane rhenium or tungsten complexes Cp*Re(E2C2B10H10)2(E=S, Se,Te),[Li(THF)4] [Cp*W(E2C2B10H10)2] (E=S, Se).

    Study on K+/H+ Exchange for K2O·4TiO2
    LU Xiao-Hua, BAO Ning-Zhong, JI Xiao-Yan, FENG Xin
    2000, 21(S1):  240-240. 
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    Potassium tetratitanate (K2O·4TiO2) is an artificial mineral whisker with the diameter of 0.5-1 μm and the length 5-20 μm. The interlayered potassium ion exchange reaction for the K2O·4TiO2 whisker results in the appearance of many new nonstoichiometric metal titanate whiskers M2O·nTiO2 (M are K, H, Na, Cs, Ba, Ru, Co or Pb, etc.). Through the K+-H3O+ exchange in solutions,TiO2 and K2O·6TiO2 whiskers were synthesized. Generally, the target product quality and yield are greatly affected by the ion exchange conditions. The optimal synthetic conditions are difficult to obtain. In this paper, a new method was proposed to control the ion-exchange process by applying the ion-exchange reaction thermodynamics and combining with monitoring the multi-ions concentrations with ISE. Ion-exchange thermodynamic model for potassium tetratitanate whisker (K2O·4TiO2) was established, and model parameters were calculated through the existent experimental equilibrium data. Ion selective electrode achieved the on-line monitor for K+/H+ exchange and the equilibrium point was judged. The calculation for the accurate ion concentration was done through the Pitzer equation. Based on the proposed method, the ion-exchange process was controlled and the optimal synthesis conditions could be obtained.

    Characterizations and Catalytic Properties of V-MCM-41 Synthesized by Template-ion Exchange Method
    WANG Ye, ZHANG Qing-Hong, TAKEHIRA Katsuomi
    2000, 21(S1):  241-241. 
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    Much attention has been paid to the use of the new mesoporous material, MCM-41,as catalyst or catalyst support[1,2]. Recently, we focus our study on the design of catalytically active sites such as vanadium species inside the mesopore of MCM-41. V-MCM-41 is generally synthesized by direct hydrothermal method in the literature, but a large part of vanadium sites seems difficult to be accessed during the catalytic reactions by this method. We have developed a novel method to introduce vanadium species by a template-ion exchange (TIE) method, i.e., by exchanging the template cation in the uncalcined MCM-41 with VO2+ ion in aqueous solution. Here, the results of the characterizations of such synthesized V-MCM-41 and its catalytic properties in oxidative dehydrogenation of propane are described.

    Synthesis and Micellar Behavior of DL-lactide-gelatin Copolymers as Amphiphilic and Biodegradable Materials
    MA Jian-Biao, CAO Hai-Hui, HE Bing-Lin
    2000, 21(S1):  242-242. 
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    A series of novel biodegradable polymers, graft copolymers of D,L-lactide on gelatin, were designed and synthesized to overcome the shortcomings of gelatin and polylactide(PLA) biomaterials. The copolymers were characterized by nitrogen analysis, IR, 1H-NMR and thermal analysis. The amphiphilic properties of these copolymers were also investigated.

    The Application of Combinatorial Chemistry in Catalysis
    ZHOU Xiao-Ping
    2000, 21(S1):  243-243. 
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    In recent few years combinatorial methodology has been extensively used in material science research. Based on the desired properties of materials, various high throughput synthesizing and screening technologies were developed. These high throughput technologies can increase our speed to more than hundred folds for finding and optimizing materials. One of the most active areas is catalysis. Scientists are developing novel high throughput technologies to screen catalyst libraries to find and optimize new catalysts for chemical industry. In this area die key is combinatorial catalytic reactor design, catalyst library synthesis, and product detection. Systematic technologies for catalyst library synthesis and characterization were developed in our laboratory. In this work, catalyst in situ synthesis, parallel reactor design, and detection methods will be introduced. Combining with the powerful combinatorial methodology, good chemistry design will make our work even more efficient. Hence, as an example of combining combinatorial technologies with chemistry design, a successful catalyst design is also introduced.

    C80(Ⅰ,Ⅱ) and Sc2@C80(Ⅰ-Ⅲ):Production, Isolation and Spectrometric Studies
    WANG Chun-Ru, SHINOHARA Hisanori, DUNSCH Lothar, ZHENG Lan-Sun
    2000, 21(S1):  244-244. 
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    C80 has seven structural isomers satisfying the isolated pentagon rule (IPR)[1],however,only one isomer of C80(D2) was isolated and studied so far[2]. In this study, we report the first successful isolation of multi-isomers of C80 and C80-based endohedral metallofullerenes. The new species were characterized by UV-Vis-NIR absorption spectroscopy, soot-extraction method, chromatographic retention time data and 13C NMR spectrometry (for C80(Ⅱ)). It is suggested that C80(Ⅱ) has a D5d symmetry by the 13C NMR pattern (3×20; 2×10) and its long retention time in 5PYE column. For the three isomers of Sc2@C80,isomer Ⅲ has an extremely long retention time which suggests a D5d symmetry. On the contrary, isomer I has a very short retention time in 5PYE columnso it may have the most spherical Ih symmetry. Theoretically, Sc2@C80(Ih) is expected to have novel super-conductivity property as the A3C60 (A=K, Rb).

    Metallosupramolecular Cube with Nanometer-sized Cavitiy
    HONG Mao-Chun, ZHAO Ying-Jun, SU Wei-Ping, CAO Rong
    2000, 21(S1):  245-245. 
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    Construction of supramolecular architectures with inner cavities is a subject of current interest because of their abilities for selective inclusion of ions and molecules, molecular recognition and catalysis for specific chemical transformations. The potential use of such species largely depends on their cavity size and type, which are mainly controlled by the ligands via appropriate metal ions. A number of such species with inner cavities have been prepared and characterized. Very recently, several metallosupramolecular capsules with enclosure-like systems and very large inner cavities were reported. Herein reported are a stable neutral nanometer-sized metallosupramolecular cube cage[Ni6(tpst)8Cl12] (1) (tpst=2,4,6-tri[(4-pyridyl)sulfanylmethyl]-l,3,5-triazine) with Oh symmetry, which was prepared from assembly reaction of NiCl2 and the tpst ligand in DMF, and[Ag7(tpst)4(ClO4)2(NO3)5]n (2) with a single stranded coordination polymer has been synthesized by self-assembly of silver salt and tpst ligand. Polymer 2 contains nanometer-sized tubes with anion and solvent molecule guests.

    SHG of Phenoanthrolinium Salts and Acridinium Salts
    SONG Hua-Can, CHEN Yi-Wen, LI Wei-Ming, YING Bai-Ning, ZOU Yong-De
    2000, 21(S1):  246-246. 
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    It becomes increasingly important to make second-order nonlinear optic (NLO) materials[1-4]. N-Hydrocarbyl-o-phenoanthrolinium salt and N-hydrocarbylacridinium salt are stable to light and heat,therefore, they are expected to be used as semi-conductor laser materials with double-frequency violet-light and blue-light (750~800 nm). Their syntheses and determination of second harmonic generation (SHG) values are in the following:

    Synthesis of Small Crystal-sized Zeolite NaY
    CHEN Guo-Zhou, CHAO Zi-Sheng, LIN Hai-Qiang, WAN Hui-Lin, TSAI Khi-Rui
    2000, 21(S1):  247-247. 
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    Comparing with their larger crystal-sized counterparts, small crystal-sized zeolites possess many advantages[1], which have been attracting extensive interests of scientific and industrial community. In this paper, we present a novel method of synthesizing small crystal-sized zeolite NaY via optimizing the mixing sequence of source materials.

    Modification of Activated Carbon Fibers and Their Characterizes of Adsorption for Xenon
    DENG Ji-Yong, ZHANG Li-Xing
    2000, 21(S1):  248-248. 
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    Activated carbon fibers (ACFs) are characterizes by their highly developed internal surface area and porosity. Especially the development of micro- and mesopores is of great importance because it allows the carbons to adsorb large amounts and various types of chemicals from gases or liquids. Due to such a valuable feature, activated carbon fibers have been in use for many years. Porous carbon materials have now become extremely versatile adsorbents of major industrial significance. The high surface area and porosity of activated carbon fibers are the result of the activation process; physical or chemical activation. However, the complexity of the carbon structure, although voluminous research has been done and great effort has been made toward the control of pore size and its distribution[1-3]. The recent development of industrial technology provides new application fields for porous carbons and,at the same time, requires the carbon to have a desired pore structure. To meet such a requirement, many novel approaches to control pore structure have been proposed.

    Synthesis of Defect-free A-type Zeolite Membrane on Porous Alumina Ceramic by Seeding
    LIN Hai-Qiang, CHAO Zi-Sheng, CHEN Guo-Zhou, WAN Hui-Lin, TSAI Khi-Rui
    2000, 21(S1):  249-249. 
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    Zeolite composite membranes have been attracting great interests due to their important potential applications in separation and catalysis. Many techniques[1] have been involved in the preparation of zeolite composite membranes. However, it is still challenged to obtain a defect-free zeolite composite membrane with high permeability. Approach of seeding and second growth was proved effective to form a homogeneous and continuos membrane[2]. This paper presents some preliminary results in our lab on the synthesis of A-type zeolite composite membrane via forming seeding layer on alumina ceramic and subsequently converting seeds to zeolite crystals composing membrane.

    Color Developing Nature of Activated Clay Using Crystal Violet Lactone
    DAI Jing-Cao, XIAO Zi-Jing, WU Hang-Yu, HUANG Ji-Tai
    2000, 21(S1):  250-250. 
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    Activated clays are a color developer for the common use of carbonless copying paper. They reacts with crystal violet lactone, a leuco dye, to form bright blue quinoid colored group with a large π bond by capturing electron pair of functional group from lactone[1].However, there exist in this reaction a problem of color stability fading in the light[2]. It is important to understand the color developing nature of clays for overcoming this problem. But unfortunately, very little work has been reported on this area[2].

    Crosslinking Reaction in the Formation of Porous Clays
    DAI Jing-Cao, WU Hang-Yu, XIAO Zi-Jing, HUANG Ji-Tai
    2000, 21(S1):  251-251. 
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    Clay minerals are a class of hydrous layer aluminosilicates of the so-called phyllosilicate[1] family made up of two basic types of layers, the SiO4 tetrahedral sheet and the Al2(OH)6[or Mg3(OH)6] octahedral sheet, many of which posses interlayer cations capable of exchanging reaction with other cations. The preparation of porous clays are based on this reactivity of exchangeable interlayer cations by using the intercalation of polycations such as Al137+ oligomers[2] into the galleries of clay minerals to form a microporous materials[3] Here we reported a study on the interlayered crosslinking of a 2:1 type montmorillonites with a hydrolysed polycations Al in the formation of porous clays. Na-montmorillonite gel (Na-mont, particle size<2 μ) were purified by using sedimentation of Na-bentonite fines (400 mesh, Zhejiang, China) and subsequent extensively washing to remove any soluble Na+. Hydrolysed polycations Al was prepared by NaOH hydrolysis of AlCl3 solutions in a condition[2] of OH/Al=2.0 and then aging at 70-90℃ for 4 h by the following process[3].

    The Nature of Titanium Porous Clays
    DAI Jing-Cao, XIAO Zi-Jing, WU Hang-Yu, HUANG Ji-Tai
    2000, 21(S1):  252-252. 
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    Porous clays is a new kind of nanocomposite prepared by intercalating metal polyoxocations between the silicate layers of clays. In recent years, this kind of inorganic mineral microporous materials displaying zeolite-like structure has raised considerable interesr[1]. Although several porous clays[2] are known, so far, a detailed understanding of the nature of titanium porous clay is still lacking. We have been particularly concerned with the relation between nature and preparation conditions of titanium porous clay. Here we wish to report the nature of porous clay containing titanium polyoxocations under different synthetic conditions.

    The First Gallium Borophosphate NaGa[BP2O7(OH)3]:Synthesis and Crystal Structure Characterization
    HUANG Y.-X., MI J.-X., MAO S.-Y., HUANG X.-D., WEI Z. B., ZHOU Z.-H, ZHAO J.-T.
    2000, 21(S1):  253-253. 
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    Borophosphates, as potential microporous materials, have drawn much attention in recent years and show rich chemistry[1-3]. Although many compounds with transition metals have been reported, compounds with the p-block main group elements participating in the framework are rare[4] The title compound has been synthesized by mild hydrothermal methods and crystal structure characterized by X-ray single crystal methods. Crystallographic data:monoclinic,C2/c (No. 15), a=10.408(3), b=8.094(2),c=9.099(2) Å, β=116.64(2), Z=4, R=0.0246,Rw=0.0676. The crystal structure contains isolated anions[(OH)O2P1/2-O1/2B(OH)2O1/2-O1/2PO3]4-. Geometrically, four GaO6 groups with four PO4 groups form an eight-member ring by sharing comers resulting to a two dimensional layer in be plane. The layers are joined by BO4 group through comer sharing with GaO6 and PO4 and result to a three dimensional network structure. A 350pm x 600pm open channel along c-axis can be seen (figure below) and occupied by Na cations.

    Study on the Interaction of Adriamycin to DNA
    LI Wen-You, XU Jin-Gou
    2000, 21(S1):  254-254. 
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    There has been considerable interest in understanding those factors that determine affinity and selectivity in binding of small molecules to DNA. These binding studies were driven partly by the need to understand the mechanism of anticancer drug action at the molecular level. The DNA binding studies with drugs have also provided a molecular basis to understand the binding and DNA sequence recognition by proteins.

    Syntheses and Structures of (Ga1-xBx)PO4, with a New Modification of High Cristobalite, and (B1-xZnx)PO4, with Low Cristobalite Type
    MI J.-X., HUANG Y.-X., MAO S.-Y., JIANG Y.-Q., ZHOU Z.-H., ZHAO J.-T.
    2000, 21(S1):  255-255. 
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    The transition metal element substitutions of the industrial catalytic material ortho-borophosphate, BPO4, can lead to either new type of structure for Cr[1] or stabilize low cristobalite structure for Mn, Fe,Co, Ni and Cu[2] Here we report our results on the substitution by main group elements Zn and Ga. The two title compounds were synthesized by high temperature solid state reactions and the structure were refined by powder diffraction methods.The structure parameters:(B0.25Ga0.75)PO4:Tetragonal, P-4, a=4.727(1), c=7.078(1) Å,V=158.17(1) Å3, Z=2, R(P)=0.0965, R(I)=0.0426; (B0.61Zn0.39)PO4:Orthorhombic, C2221 a=7.080(1), b=7.087(1),c=6.990(1) Å, V=350.71(2) Å3, Z=4,R(P)=0.0904,R(I)=0.0438. Pure GaPO4 were found three kinds of structures, low- and high-cristobalite and high -quartz with an observation of an unknown unstable high cristobalite at high temperature[3] The boron substitution of the high-cristobalite GaPO4 with space group I-A leads to lower symmetry space group(P-4). We assume the low symmetry structure related to the unknown unstable phase. The structures of both compounds are similar to very well known cristobalite (see figure below).

    The Fluorescence Properties of Binary and Ternary Complexes of CMC in Solid State
    YE Jun, XIONG Jian, HE Xiao-Wei, FAN Pei-Ming
    2000, 21(S1):  256-256. 
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    In comparison with synthetic polymers, cellulose complexes are attractive for practical applications, owing to their non-toxicity and biodegradability. R Pemnikis and his coworkers studied the gel-properties of the complexes of CMC (or OECMC)/Al3+ (or Fe3+ and its applications in agriculture as biologically active substance carriers⑴.The fluorescence behavior of binary complex of CMC/Eu(Ⅲ) in solid state has been reported[2,3]. It emits 615 nm fluorescence at 394 nm excitation wavelength. Its Fluorescence Intensities (FI) were difference with different the concentration of Eu3+ and Degree of Substitute of CMC, but its Fluorescence Spectrum was not affected by these parameters.

    A Kinetic Study on the Thermal Decomposition of Three Kinds of Initiators in Styrene
    HUANG Hong-Jun, YAN Jun, ZHANG Wen-Yu, REN Feng-Zhi, WANG Xing-Fang
    2000, 21(S1):  257-257. 
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    The synthesis of polystyrene plays an important role in the macromolecule industry. In this article, AIBN、BPO and dl-Diethyl-2,3-Dicyano-2,3-Diphenylsuccinate(Ⅰ) were chosen as initiators of styrene. From the curve of conversion(α) and time(t) (chart omitted), we can get the decomposition velocity constant (kd)、the decomposition activation energy (Ed) of these initiators and the final conversion(α∞) of styrene.(Table 1).

    The Correlation Between the α-γ Transition of Cast Copolyamide and the Mechanical Properties
    GAO Jian-Guo, CHEN Yu-Ping, WANG You-Huai, HE Jia-Song
    2000, 21(S1):  258-258. 
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    In this work,we have examined changes in the spherulite structure of cast nylon 6 due to copolyether as a function, in particular,we focused on revealing to α-γ transition and the effect of α-γ transition on mechanical properties by the methods of X-ray diffraction and of infrared spectroscopy.

    Changes in the Morphology of Cast Nylon through Copolymerization
    GAO Jian-Guo, CHEN Yu-Ping, WANG You-Huai, HE Jia-Song
    2000, 21(S1):  259-259. 
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    In this paper, the effect of copolyether (PPG/PTHF) on morphology of cast nylon 6 was studied by means of DSC、SEM、DLIM (depolarized light intensity method), the result shows:PPG/PTHF-PA copolymer is a semicompatible system. PPG/PTHF-PA (polyamide) copolymer with different molecular weight from Mn=4400 to 10000 have different compatible. The results also show the compatibility and the degree of crystallization of cast nylon appear peak transformation with the increasing copolyether content and the increasing molecular weight of copolyether. It is also found that the permeation of copolyether segment toward polyamide substrate may be considered as general phenomenon, spherulite size of polyamide became smaller, crystallization behaviors was bad.The copolyether acted as nuleator in the crystallization of cast nylon. It is found that while compatible copolyether was dispersed in PA matrix as if a kind of filler, PA keeps good spherulite structure, at the same time,the mechaninical properties of the copolyamide is better than pure cast nylon 6.

    Nanoparticles of Pd Confined in Supercages of Y-zeolite:Enhanced IR Absorption and Electrocatalytic Properties
    JIANG Yan-Xia, SUN Shi-Gang
    2000, 21(S1):  260-260. 
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    Platinum group metals possess high stability and activity in electrocatalysis and are frequently used in fuel cells[1].However, their commercial applications are limited owing to the high cost. Accordingly, one of the most important subjects of electrocatalysis is to select suitable substrate materials to disperse platinum group metal and prepare electrocatalysts of high performance and low cost. In this paper, nanoparticles of palladium (Pd13) were synthesized in supercages of Y-zeolite according to the procedure of literature[2] The electrode of palladium-loading zeolite film supported on Pt substrate (Pd0Y/Pt) was characterized by cyclic voltammetry, and the adsorption of carbon monoxide on the electrode was studied using in situ electrochemical FTIR reflection spectroscopy.

    Studies on Zero Point of Charge and Permanent Charge Density of Mg-Fe Hydrotalcite-like Compounds
    HOU Wan-Guo, SU Yan-Lei, SUN De-Jun, ZHANG Chun-Guang
    2000, 21(S1):  261-261. 
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    The theoretical analysis on the zero point of charge (ZPC) and charge density of colloidal particle possessing permanent charges indicates that ZPC determined directly by means of potentiometric titration (PT) should be zero point of net charge (ZPNC) and the permanent charge density (σP) can be obtained from the adsorption amount of H+ and OH-(ΓOH--ΓH+) at ZPNC. ZPNC does not change with the electrolyte concentration while the zero point of variable charge (ZPVC) changes with the electrolyte concentration. When σP is zero, ZPNC equals to ZPVC, and only under this condition is ZPC measured directly by PT equal to ZPVC. The relationship between ZPNC, ZNVC, σP, the variable charge density (σV)5 or the total net surface charge density (σT) with pH or electrolyte concentration is derived.

    Low Temperature Sintering and Characterization of YSZ/Al Composite Coatings by Electrophoretic Deposition and Reaction Bonding Process
    WANG Z., XIAO P., SHEMILT J., LIN Chang-Jian
    2000, 21(S1):  262-262. 
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    In practice, low temperature sintering is always the most desirable route to fabricate ceramic composites for industrial manufacturers and an economic way to produce ceramics with unique microstructure for technological applications. Normally the sintering temperature for dense YSZ coating is about 1500℃. Recently many studies have experimentally found that dense ceramic composites can be achieved at a sintering temperature lower by several hundred degrees Celsius for nano-sized powders than for coarse powders[1-2]. Electrochemical processing is an attractive method for making ceramic films and powders because it offers the advantages of low temperature sintering, low cost and good control of the green forms[3-4].

    Novel Synthesis of Nanometer Crystal-sized Zeolite NaY by Adding Lanthanum-containing Compounds
    CHAO Zi-Sheng, CHEN Guo-Zhou, LIN Hai-Qiang, WAN Hui-Lin, TSAI Khi-Rui
    2000, 21(S1):  263-263. 
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    Nanometer-sized zeolite possesses many distinct advantages[1,2] comparing with its commercially available micrometer-sized counterpart[3], and receives much attention in recent years. In this work, a novel synthesis of nanometer-sized zeolite NaY is presented.

    Preparation of Gd-Ni Film Alloy in Urea-NaBr Melt
    LIU Li-Zhi, XU Chang-Wei, LIU Gui-Hua, TONG Ye-Xiang, LIU Guan-Kun
    2000, 21(S1):  264-264. 
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    Gd in 4f lanthanon has ferromagnetic-paramagnetism transform temperature (Curie point) and the highest magnetic thermal entropy change at room temperature. So far, it is still the best magnetic refrigeration working substance material. The systems of urea with some alkali metal salts have lower melting point (301~389 K)[1], greater solubility of metal chloride and higher conductivity[2]. In this paper, the electrode processes of Ni (Ⅱ) reduced in urea-NaBr melt, electrodeposition of nickel with gadolinium, and the surface morphology and the structural states of electrodeposited films and films after heat treatment have been investigated.

    Molecular Films Assembled from Viologens and Anionic Species:Preparation, Characterization and Applications
    CAI Li-Rong, LI Xiao-Yuan
    2000, 21(S1):  265-265. 
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    Viologens are a class of cationic molecules containing 4,4'-bipyridinium structural unit. They display very interesting redox chemistry and redox-state-dependent photochemistry. Their special redox and optical properties found many applications in electrocatalysis, photocatalysis, electron mediation, and electro- and photochromism. Synthetically, various functional groups can be attached to the bipyridium unit by covalent linkages, making it possible to extend the chemical and physical properties of viologens[1,2].

    Finite-field Studies on the Second-order Hyperpolarlizability of MHBA
    LIN Chen-Sheng, WU Ke-Chen
    2000, 21(S1):  266-266. 
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    As a new nonlinear optical organic material, MHBA (3-Methoxy-4-Hydroxy-Benzaldehyde) crystal[1] has been grown into a size of 70 mm×40 mm×20 mm. Its second-harmonic generation (SHG) is about 30 times larger than that of urea, and has a suitable transparency in the range from 370 nm to 1700 nm. MHBA can be used to realize direct frequency doubling of near infrared diode laser to generate violet-blue light at room temperature. We have discussed its SHG by using finite-field method[2~3]. However there is no report on the third-harmonic generation (THG) properties of MHBA. In this study we will theoretically investigate the molecular second-order hyperpolarizabilities of MHBA.

    New MoO3 Phase:Synthesis and Structure of (NH4)0.66MoO3
    YANG Wen-Bin, LU Can-Zhong, LIN Xiang, WU Chuan-De, ZHUANG Hong-Hui
    2000, 21(S1):  267-267. 
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    Gentle reduction of solid MoO3 leads to four distinct phase of HxMoO3. These compounds have a wide range of colors and crystal classes:phase Ⅰ (0.25< x< 0.40), blue, orthorhombic; phase Ⅱ (0.85< x< 1.04), blue, monoclinic; phase Ⅲ (1.55< x< 1.72), red, monoclinic; and phase Ⅳ (x=2.0), green, monoclinic[1-3]. We have now obtained a new MoO3 phase (NH4)MoO3 with network structure from an aqueous solution of Na2MoO4 reduced by NH2NH2·2HC1 at 170℃.

    A Novel Ferroferric Polyoxotungstate:Synthesis, Structure and Magnetic Properties of Na5[Fe2.5(H2O)10W12O42]·ca.32 H2O
    YANG Wen-Bin, LU Can-Zhong, LIN Xiang, ZHUANG Hong-Hui
    2000, 21(S1):  268-268. 
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    Due to the variety of their components, structures and properties, significant attention continues to be focused on the polyoxometalatic anions in many research fields such as catalysis, biology, medicine and materials science1. When the aqueous solution of Na2WO4·2H2O was reduced by iron powder in CH3COOH (30%), crystals of Na5[Fe2.5(H2O)10W12O42]·ca.32 H2O 1, which crystallizes in the triclinic space group P 1 with a=12.121(2), b=12.426(3), c=l3.247(3) Å, α=68.33(3), β=71.33(3), γ=71.44(3)° and Z=l, precipitated after several weeks.

    Preparation and Performance of a Novel Bifunctional Catalyst for Autoxidation of Mercaptans
    LIU Hai-Chao, YANG Xi-Yao, RAN Guo-Peng, MIN En-Ze
    2000, 21(S1):  269-269. 
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    Cobalt phthalocyanine (CoPc) complexes in the presence of caustic are widely used in the refining industry for sweetening (i. e. the catalytic oxidation of mercaptans to disulfides) of petroleum products[1]. However, the use of caustic leads to the environmental and economic disadvantages because the spent caustic is recognized as a hazardous material. To set up a more environmentally friendly process, Holmgren et al. and Liu et al. recently reported that bifunctional mixed Mg-Al oxide (denoted as Mg(Al)O)-supported CoPc catalysts, which possess oxidation sites and basic sites, can effectively oxidize mercaptans to disulfides[2,3]. But for these catalysts, we found that the formation of CoPc aggregates on Mg(Al)O during the autoxidation led to their deactivation.3 It is known that the aggregation can be inhibited by anchoring CoPc to supports, such as TiO2 and SiO2, modified with organic functional groups. However,it is unknown whether the basic Mg(Al)O materials can be functionalized with organic compounds with no damage to their basic sites. Here we report the preparation of a novel bifunctional catalysts of cobalt tetraaminophthalocyanine CoPc(NH2)4 covalently bound to Mg(Al)O modified with a organosilane, as well as their catalytic performance in mercaptan autoxidation.

    Hybrid Bioceramic Coatings of Calcium Phosphate Prepared by Electrodeposition Technique
    HU Hao-Bing, LIN Chang-Jian
    2000, 21(S1):  270-270. 
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    The electrodeposition of bioceramic coatings of calcium phosphates on metal substrate is a newly developed method for preparing implanted bio-medical devices[1-2]. It is proposed to have a remarkable higher bioactivity and excellent bio-capability for the electrodeposited bioceramic coating, because it may produce a pure structure and composition of hydraxiapatite (HAP) during electrodeposition process at room temperature. However, the bonding force of electrodeposition bioceramic coating to the metal substrate is too weak. It has become a major problem in developing electrodeposition technique for preparing bioceramic coatings of calcium phosphates on metal substrate. The present work has been emphasized to develop an approach for preparing HAP bioceramic coatings, which has strong bonding force both in the bulk phase of HAP coating and to the metal substrate.

    KCaEr2CuS5:A Novel Pentanary Rare-earth Chalcogenide from Reactive Flux Synthesis
    ZENG Hui-Yi, MAO Jiang-Gao, DONG Zhen-Chao, GUO Guo-Cong, HUANG Jin-Shun
    2000, 21(S1):  271-271. 
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    Chemists have been paying much attention to the multiple-component rare-earth chalcogenides both for the fundamental interest of their varieties of structural features and in the search of potential candidates for luminescent materials, magneto-optical materials,infrared materials, and high-temperature superconducting materials[1-2]. It is widely realized that during the synthesis and crystal growth via flux methods, occasional inclusion of flux elements in the final product is inevitable and often leads to unexpected and interesting new structures.

    Chemistry in Surface Science
    Synthesis and Structure of KLn2CuSe4 (Ln=Ho, Er), A New Phase with IR-optical Transparency
    ZENG Hui-Yi, MAO Jiang-Gao, CHEN Jiu-Tong, DONG Zhen-Chao. GUO Guo-Cong, HUANG Jin-Shun
    2000, 21(S1):  272-272. 
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    Research on rare earth chalcogenides has been an active.area of solid state chemistry due to their rich structural chemistry and various interesting physical properties[1-3]. In our attempts to search for potential infrared ceramic materials in the rare-earth-transition-metal chalcogenide system, two new quaternary selenides, KHo2CuSe4 and KEr2CuSe4, were obtained by a two-step synthetic route. Precursors from the first-step solid state reaction were mixed with excess amount of the KCl flux. The pressed pellet was placed into a sealed silica ampoule and thermally equilibrated at 930℃ for 8 days prior to slow cooling to room temperature. Red,transparent, and columnar single crystals of these two phases were isolated from the flux by a suction filtration technique with the products washed with distilled water. The incidental incorporation of the flux cation leads to the formation of the new phases.

    Chemistry in Materials Sciences
    Studies of a Copper Phthalocyanine Containing Four Benzo-15-crown-5 Moieties
    LI Yong, FENG Fu-De, DU Xi-Wang
    2000, 21(S1):  273-273. 
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    A copper(Ⅱ) phthalocyanine containing four benzo-15-crown-5 moieties was successfully synthesized from 4',5'-dibromobenzo-15-crown-5. The electronic absorption spectra of the phthalo-cyanine in chloroform-methanol with different amounts of KCl were measured. One can find that when the[K+]/[phthalocyanine] ratio is increased from 0 to 2, the peak at 678nm is decreased and finally disappears, and at the same time the peak at 630 nm appears and is increased.

    In-situ Growth of Oriented MCM-22 Zeolite Films on Glass Substrates
    CHENG Mo-Jie, TAN Da-Li, BAO Xin-He
    2000, 21(S1):  274-274. 
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    Zeolites are crystalline materials which have channels several angstroms to nanometers in size, which are accessible to various inorganic and organic molecules with size and configuration selectivities. In-situ growth of zeolite films on surfaces is of significant importance in utilizing the well-defined intracrystalline pores for membrane separation, membrane catalysis, molecular sensors and optoelectronic devices. For zeolites with one-or two-dimensional pore system, the accessibility of zeolite pores in films depends on crystal orientation.

    Low Temperature Preparation and Absorption Spectra of Nanocrystalline Pb1-xLaxTiO3 Thin Film on ITO Conducting Glass Substrate
    QIU Fa-Binac, GUO Kui, ZOU Bo, WANG Yong-Wei, QUAN Bao-Fu, LI Xi, HUANG Xi-Min
    2000, 21(S1):  275-275. 
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    Nanocrystalline precursors of Pb1-xLaxTiO3 (PLT, x=0.06, 0.10, 0.14 and 0.20) thin film were prepared on ordinary ITO conducting glass substrate using sol-gel and pulling method. After the precursors were calcined at low temperature of 185-400℃ in air atmosphere for 1-6 h, the resulted nanocrystalline thin film was characterized by XRD, SEM and AFM. The spectra show that the solid state chemical reaction and the grain size of the nanocrystalline thin film relate not only to the precursor preparing method, but also to the distribution of different components in the precursor. The UV-VI spectrum measurement of the transparent PLT film indicates that its optical absorption bands have extended into the visible region and a change in its absorption pattern with the increase of mean grain size was also observed. As the transparent nanocrystalline PLT thin film with small grain size possesses wider optical absorption band in range of 320-800 nm, the material of Pb1-xLaxTiO3 with suitable component and mean grain size can be used in the fabrication of dye-sensitized photoelectronchemistry solar cell instead of TiO2. And the higher photoelectric efficiency can be expected.

    Quantify the Maximum Limit Value of the Framework Ti Content in TS-1
    ZHOU Ji-Cheng, WANG Xiang-Sheng
    2000, 21(S1):  276-276. 
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    The substitution of Si4+ by Ti4+ in titanosilicates is always limited, originally, Taramasso et al. prepared TS-1 with more than≈2wt% titanium in the lattice. Both XANES and XPS allow to titrate framework tetrahedral Ti and extra-framework TiO2 anatase species. There was no detectable extra-framework Ti up to 1.5wt% Ti, above 1.5%. A limit of ca.1.8% of Ti incorporation into the framework of the S-lsilicalite has been calculated by titration using Raman spectroscopy or using voltametric measurments, XRD and Rietveld calculation of the unit cell expansion led to higher limit of ca.2.5%. Higher level of incorporation of as much as ca.6 and 8% were claimed. Therefore, the maximum of Ti incorporation is still a controversial matter that prompted us to develop a new technique to quantify them.

    Study on the Ammoximation of Cyclohexanone to Cyclohexanone Oxime Catalyzed by Titanium Silicalite-1 Formed in Inorganic System
    ZHOU Ji-Cheng, ZHAO Hong
    2000, 21(S1):  277-277. 
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    The conventional and modified synthesis of titanium silicalite-1 is in the organic system[1,2]. We have reported the TS-1 could be prepared with colloidal SiO2 and TiCl3 as Si source and Ti source respectively in inorganic system[3]. The present paper deals with the ammoximation of cyclohexanone to cyclohexanone oxime over TS-1 prepared by the method described above. Tests are carried out for 5 hours at 65℃,with NH3 and H2O2 in the liquid phase, acetone as solvent, reactants adding to reactor all at once over these two kinds of TS-1. The results show that oxime yield over TS-1 produced in inorganic system is as good as or better than that catalyzed by conventional TS-1 at the same conditions. More over, more satisfied yield of oxinone could be achieved if it reacts at some optimal reaction conditions[4,5]. In addition, the same result has been reached at the epoxidation of propylene catalyzed by these two kinds of TS-1 Following table is the results of reaction catalyzed by these two kinds of TS-1.

    A Study on the Anticorrosion of LD-1 Compound Inhibitor on Reinforcing Steel in Seawater
    DU Rong-Gui, HU Rong-Gang, HUANG Ruo-Shuang, FENG Zu-De, LIN Chang-Jian
    2000, 21(S1):  278-278. 
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    Corrosion of reinforcing steel in concrete is one of major causes of the loss of durability in marine environment and in those environments contained chloride ions. A number of protective measures have been applied for preventing reinforcement corrosion, and corrosion inhibitors have been developed, which is effective and economical for combating the corrosion problem. This paper shows the evaluation of the effect of LD-1 compound inhibitor, which has been developed in our laboratory, on its anticorrosion action on the reinforcing steel in seawater for the sake of preventing reinforcing steel in concrete in marine environment corrosion.

    AFM Study on the Surface of Reinforcing Steel in Simulated Concrete Pore Solution
    HU Rong-Gang, DU Rong-Gui, HUANG Ruo-Shuang, LIN Chang-Jian
    2000, 21(S1):  279-279. 
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    Atomic Force Microscopy (AFM) is a powerful technique to study corrosion processes in the μm- and nm- range because it is able to provide real space images of the surface with high spatial resolution while the operation is simple and fast and the sample is free from exposure to high vacuum atmosphere in which some properties may deviate from those under common pressure. Microscopic study on the topography of the surface layer of passivated metal is of great importance to abstaining better understanding of localized corrosion, especially the early stage of this process. In this paper a systematic AFM study on steel in simulated concrete pore solution (SPS) was carried out in order to illustrate the relationship between the stability of passive film at the surface of the steel and aggressive species in the solution and evaluate the effect of several inhibitors on corrosion resistance of reinforcing steel.

    Fabrication of IrO2 H+ Sensor and Its Application in the Measurement of pH at Steel/Concrete Interface
    HU Rong-Gang, HUANG Ruo-Shuang, DU Rong-Gui, LIN Chang-Jian
    2000, 21(S1):  280-280. 
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    Corrosion of steel reinforcement is the most serious threat to the service life of modem reinforced concrete structure and the corrosion behavior of the steel reinforcement has a close dependence on the chemical environment at the steel/concrete interface. Among all the species which can affect the corrosion rate, H+ is of the greatest influence on the stability of the steel bars. However, the in-situ measurement of pH value at steel/concrete interface is still underway. In this paper fabrication of Ir oxide electrode which serves as the pH probe working at the steel/concrete interface was explored.

    Preparation and Characterization for the Electrodeposited Hybrid Coating of Calcium Phosphate/Chitosan on Ti Alloy Surface
    HU Ren, HU Hao-Bing, LIN Chang-Jian
    2000, 21(S1):  281-281. 
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    Hydroxyapatite (HA) formulated as Ca10(PO4)6(OH)2 becomes a favorable material for implants because of its chemical similarity to the calcium phosphate minerals present in biological hard tissue. Many efforts have been made in recent years in the development of processing methods for depositing hydroxyapatite on implant alloy substrate in order to have high strength, good processability, suitable specific density, excellent corrosion resistance in the physiological environment and good affinity to the living body. The plasma spray technique is commonly used in the HA coating on implants. The major problem for the plasma spray, however, is the decomposition and phase transformation of hydroxyapatite during the spray coating process. Electrochemical techniques including electrophretic deposition and electro-deposition are being developed as an alternative method for producing hydroyapatite coated composite material. It is very desirable at present to further strengthen the coating and bond it to the metal substrate, and to increase the bioactivity of hydroxyapatite coatings as well, which is very important for forming a strong chemical bond with natural bone as an implant material.

    Synthesis and Characterization of Diatomaceous Earth-based Iron Porphyrin Nanocomposite Material and Its Electrocatalytic Activity towards the Reduction of BrO3-
    JIANG Yan-Xia, SUN Shi-Gang, WANG Xing-Qiao, GUO Jing-Zhi, XU Hong-Ding
    2000, 21(S1):  282-282. 
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    The water-soluble metalloporphyrin is one of the most promising classes of compounds to be used as redox mediators/catalysts. In recent years, there has been increasing interest in the heterogeneous catalysis of metalloporphyrin, owing to the catalyst support on inorganic material not only maintain beneficial properties of catalyst, but also improve their catalytic activity and selectivity[1]. For that purpose, scientists begin to search proper support to immobilization metalloporphyrin catalysts. In general, silica, alumina, zeolite, and clay minerals were utilized as matrixes to immobilize the metalloporphyrin.

    A Novel Method for Preparation of Nanometer ZnO
    CHEN Shang, XIAO Zhuo-Bing, LIU Jian-Ben, ZHANG Yong-KANG
    2000, 21(S1):  283-283. 
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    In spite of many methods have been developed for preparation of nanometer ZnO, e.g. colloidal-gel, vacuum vaporization-condensation et al,its still not easy and convenient to prepare nanometer particle practically. A novel method proposed here enables us to prepare it conveniently via gas_solid phase reaction.

    The Study on Electrochemical Stability of Amorphous Ni-S Alloy Electrode
    DU Min, GAO Rong-Jie
    2000, 21(S1):  284-284. 
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    Development of cathode material which has low HER (hydrogen evolution reaction) overpotential and high durability is significant to electrolysis industry and antifouling with electrolyzing seawater. The amorphous Ni-S alloy electrode was prepared by means of electrodeposition. Its electrocatalytic activity and stability for HER in 5 mol/L NaOH solution at 353 K was investigated. The result showed that the amorphous Ni-S alloy in which sulphur content is 29.4%, has high electrocatalytic activity and excellent stability. In addition, the morphology and phase structure of the NiSx alloy electrode before and after electrolysis were studied by SEM (scanning electron microscope) and XRD (X-ray diffraction).

    Preparation of Nanocrystalline Titania Directly from Industrial Titanium Hydroxide
    GAO Rong-Jie, DU Min
    2000, 21(S1):  285-285. 
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    Nanocrystalline titania was prepared directly from industrial titanium hydroxide by NH4NO3 decomposition at 573K. DTA-TG, XRD, TEM and BET were employed to character the sample.The DTA-TG curves were measured by differential thermal balance to detect the phase transformation temperature of samples. Using α-Al2O3 as the standard substance. XRD was used to determine the phase composition of titania powders on a diffractometer (RIGUKU, Cu Kα=0.15406 nm, 40 kV). Crystallite sizes were determined from line broadening measurements by using Scherrer formula. TEM image of sample was obtained on a Phillips EM420 microscope, operating at l00kV and the special surface and pore volume are examined by BET method.

    Synthesis of Mesopore Y Zeolite
    MA Bo, SUN Wan-Fu, SUN Zhao-Lin, CHEN Li-Ren
    2000, 21(S1):  286-286. 
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    Y zeolite has been widely used in the petroleum processes, especially in the fluid catalytic cracking and hydrocracking catalysts. The catalytic performance of the Y zeolite depends strongly on the modification; it is well recognized that the mesopore Y zeolite with diameters between 0.8-60 nm is good for cracking large molecules. To obtain this kind of Y zeolite, chemical modification in hydrothermal treatment is one of effective methods.

    Synthesis of Binaphthol Based Poly(arylene) Dendrimers and Their Use as Enantioselective Fluorescent Scensors
    GONG Liu-Zhu, PU Lin
    2000, 21(S1):  287-287. 
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    New optically active dendrimers (1-3) containing rigid and cross-conjugated units have been synthesized and characterized. UV and fluorescence spectroscopic studies demonstrate that the energy harvested by the periphery of the dendrimers can be efficiently transferred to the core. The fluorescence of the dendrimers can be quenched by amino alcohols (4-6) both efficiently and enantioselectively. The energy migration and light harvesting effects of the dendrimers make the higher generation dendrimers more sensitive fluorescent quencher than the lower ones.

    Catalytic Reduction of Nitric Oxide on SiO2/AlO3-supported Transition Metal Catalysts
    LI Wei-Bin, YING Gao-Xiang, ZHANG Yu
    2000, 21(S1):  288-288. 
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    Selective reduction of nitric oxide in pressence of oxygen is one of the major challenges in the automobile exhaust after-treatment for lean-bum gasoline engines and diesel engines. Besides Cu-ZSM-5, Pt and Pd based noble metal catalysts, alumina-supported silver catalysts show high activities on NOx conversion to nitrogen[1,2]. However, NO conversion activities over silver on binary oxides have rarely been studied in detail[3], although copper on SiO2-Al2O3 catalyst was reported to have a high activity[4] Here, NOx reduction activities on SiO2-Al2O3-supported transition metal catalysts prepared by sol-gel method was investigated.

    Reversible Adsorption of NOx on ZrO2-supported CeO2 Prepared in Water-in-oil Microemulsion
    LI Wei-Bin, YANG Xu-Fei, MA Hong, WANG Hong
    2000, 21(S1):  289-289. 
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    Nitric oxides (NOx) storage catalyst[1] provides an alternative route for abatement of NO in presence of oxygen by first adsorbing NOx and then desorbing it by temperature swing or pressure swing. YBa2Cu3Oy[2] and Mn-Zr mixed oxides[3] were reported to have large NOx adsorption capacity, but the former suffered from a great amount of coexisting CO2 gases. The author previously reported that high NOx adsorption capacity could be obtained on Ce modified TiO2-pillared montmorillonite without deactivation by CO2[1]. Microemulsion method was reported to be effective to control particle sizes and microstructures of the metal oxides[4]. In this paper, a thermal stable ZrO2 with high surface area was prepared in water-in-oil microemulsion, and NOx adsorption capacity was tested on the above ZrO2 sample after impregnating with manganese nitrate and cerium nitrate.

    Using Valence Bond Theory to Understand Electronic Excited States:Application to the Hidden Excited State of Linear Polyenes
    WU Wei, DANOVICH David, SHURKI Avital, SHAIK Sason
    2000, 21(S1):  290-290. 
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    A VB method is presented and applied to calculate the hidden excited states, 21Ag and other covalent excited states of polyenes from C4H6 to C28H30. The ground rules needed to understand the results are qualitatively outlined and used to discuss the asymptotic behavior of these molecules as n goes to infinity. The theory enables to understand in a coherent and lucid manner excited state properties, such as the make-up of the various states, their energies, geometries, the puzzling increase of the C=C frequency in the excited state, the opposite bond alternation properties of the ground and excited, isomerization patterns, soliton characters, etc.

    Effects of Ultraviolet Illumination and Pre-treatments on Porous Silicon Formation
    LUO Guang-Feng, CHENG Xuan, LIU Feng-Ming, LIN Chang-Jian, TIAN Zhong-Qun, XUE Ru
    2000, 21(S1):  291-291. 
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    Although porous silicon is readily formed by anodizing silicon wafers in HF-based solutions, its application in silicon-based optoelectronic devices is greatly limited due to its poor stability and low luminescence yield. It is well recognized that the nature of silicon wafers and the fabrication condition parameters significantly influence uniformity, stability and optical properties of porous silicon. In this work, the ultraviolet illumination and pre-treatments were investigated for porous silicon formation. The surface morphologies and optical properties of the samples were also studied.

    Influence on the Inclusion Complexation between C60 and Calix[8]aryl Ester by Some Rare Earth Metal Cations
    ZHANG Hui, LIN Jun, ZHOU Zhao-Hui, CHEN Jian-Gu, CHEN Zai-Hong
    2000, 21(S1):  292-292. 
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    Fullerenes are sort of new substances which have a good number of novel physical and chemical properties. The supramolecular inclusion complexes formed by fullerenes and some compounds are of importance to many fields.

    Two-photon Excitized Luminescence for A Hexa-europium(Ⅲ) Dendrimer Containing Indole, Pyrazole and S-triazine
    YANG Chi
    2000, 21(S1):  293-293. 
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    There has been increasing interest recently in metallodendrimers possessing novel physical, electrochemical, photochemical, biological, and catalytic properties[1]. We report here our approach for contructing novel metallodendrimers showing two-photon luminescence properties.

    A New Method of Preparing of Zinc Oxide Nanopowder——Ultrasonic Radiation Precipitation
    WANG Wen-Liang, LI Dong-Sheng, YANG Wen-Xuan
    2000, 21(S1):  294-294. 
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    In the recent years, the study on ultrasound used to synthesis nanomaterials has attracted much attention of chemists, physicists and material scientists. Suslick et al[1] had prepared amorphous nano-sized iron with sonochemistry method. Liang et al.[2] investigated synthesis of LaCoO3 nanocrystalline by coprecipitation under ultrasonic radiation.

    Preparation of Ultrafine Ceramic Powder Used for Making PTCR Ceramics by Sol-gel Method
    LI Dong-Sheng, WU Shu-Rong, XONG Wei-Miao, WANG Wen-Liang, WANG Ji-Wu
    2000, 21(S1):  295-295. 
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    Amorphous gel powder containing Ba, Sr, Ca, Ti, Si, Mn, Li and Y elements has been prepared by a modified sol-gel method, the ultrafine PTCR (Positive Temperature Coefficient of Resistance) powder was obtained through calcination for 2 h at 800℃ in air. According to XRD, DSC, BET and SEM. it can be concluded that it's crystal structure is cubical perovskite phase at room temperature, it's average crystallite size is about 28.4nm (using the Debye-Scherrer formula) or about 40 nm (using BET) or about 50nm(using SEM), it's specific surface area is 24.80 m2/g, and which is two twice as much as that of the sample prepared by old sol-gel method[l,2], it's particle size displays normal distribution with average particle size of 437.2nm.

    MCM-41 Supported Rhenium Oxides:Characterization and Selective Methanol Oxidation
    YUAN You-Zhu, CAO Wei, YU La-Jia, YANG Yi-Quan, LI Zhi-Hua
    2000, 21(S1):  296-296. 
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    Re oxides have not widely been used as catalysts for selective oxidations owing to sublimation under pretreatment and reaction conditions[1].Nevertheless, the property of Re species capable of adopting a variety of oxidation states that are illustrated in both binary and ternary oxides[2,3],may provide rich and interesting chemistry. One of us reported a crystalline binary oxide compound SbRe2O6 for the selective methylal formation in the methanol oxidation[4]. The selectivity reached 92.5% at a conversion of 6.5% at 573 K. The performance of SbRe2O6 was attributed to the Re-oxide octahedra connecting with Sb-O chains[5]. However, the crystalline oxide SbRe2O6 has a very low surface area (1 m2 g-1),resulting in insufficient activity for the methylal production. Recently, we found the new catalytic property of supported Re oxides for the selective oxidation of methanol to methylal[6]. Here, we report the characterization and catalytic property of MCM-41 supported Re oxides for the selective methanol oxidation.

    Rhodium Complexes of Aminophosphines for 1-hexene Hydroformylation
    CAO Wei, YUAN You-Zhu
    2000, 21(S1):  297-297. 
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    Hydroformylation is one of the most versatile methods for the functionalization of C=C bonds. The rhodium phosphine catalysts, introduced by Wilkinson, have been shown to be more selective, and they give higher rates under milder conditions than the older cobalt carbonyl catalysts. The steric and electronic properties of the ligands have a dramatic influence on the reactivity of organo-metallic complexes. Despite recent extensive investigations on structure-reactivity correlation, the effects of electronic and steric parameters of P-liangds on the catalytic activity of rhodium catalysts, however, are not always predictable[1,2] Here we present a study of the effect of a series of aminophosphines on the rhodium-catalyzed hydroformylation reaction.

    Effects of Cerium and Combination of Fluoride and Cerium on the Hydrolysis of Hydroxyapatite and Calcium Hydrogen Phosphate
    FENG Zu-De, CHEN Fei, LIN Chang-Jian
    2000, 21(S1):  298-298. 
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    Researches have indicated that fluoride aided in decreasing the solubility of enamel of teeth and preventing caries through converting hydroxyapatite (HAP) to less dissoluble fluoroapatite (FAP). However, The toxicity of fluoride is not negligible. Recent studies[1] suggested that rare-earth elements (for instance,lanthanum, cerium, etc.) might play an important role in enamel demineralization reduction. However, the effect of these rare-earth elements on the solubility of HAP and calcium hydrogen phosphate (CaHPO4·2H2O, DCPD),which are the major inorganic compositions in enamel, remains unclear. The purpose of this paper was to investigate the characteristics of the hydrolysis of DCPD and HAP under 37℃ when hydrolyzed (a) in solutions containing cerium alone, and (b) in solutions containing fluoride followed by solutions containing cerium, respectively.

    Electrophoretic Deposition of Hydroxyapatite from Non-aqueous Media
    FENG Zu-De, JIANG Yang, ZHANG Jian-Ming, DU Rong-Gui, LIN Chang-Jian
    2000, 21(S1):  299-299. 
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    Hydroxyapatite Ca10(PO4)6(OH)2 (HA) is an important material for bone and tooth implants, as its chemical composition is similar to that of bone tissue. Owing to the inferior mechanical properties of HA, significant research activity has been associated with the development of HA coatings and composites. The interest in electrophoresis for biomedical applications steins from a variety of reasons such as the possibility of deposition of stoichiometric, high purity material to a degree not easily achievable by other processing techniques and the possibility of forming coatings and bodies of complex shape[1]. In this work, the experimental results of a study of electrophoretic deposition of HA powders, performed in isopropyl alcohol or ethanol as a suspension medium, are reported.

    The Effect of Sodium Fluoride Solution on the Hydrolysis of β-tricalcium Phosphate and the Solubility of its Hydrolysate
    FENG Zu-De, JIANG Yang, CHEN Fei, LIN Chang-Jian
    2000, 21(S1):  300-300. 
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    β-Tricalcium phosphate (β-Ca3(CO4)2; β-TCP) is one of the main inorganic components of bone and teeth. In addition, in hydraulic calcium phosphate cements β-TCP has been considered to be an important phase[1]. Since the anticaries effect of fluoride was found in 1940's, much effort was made in the aspect of the fluoridation of HAP. However, to our knowledge no article published on the effect of fluoride ion on the hydrolysis of β-TCP. The purposes of this study were to investigate the hydrolysis characteristic of β-TCP in NaF solutions and the solubility of the hydrolysates.

    Composition Effects on the Acidity and Properties of Hydraulic Calcium Phosphate Cements
    FENG Zu-De, JIANG Yang, HUANG Ya-Xi, DU Rong-Gui, LIN Chang-Jian
    2000, 21(S1):  301-301. 
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    Hydraulic calcium phosphate cements (HCPC) are considered as the potentially useful materials in a great variety of medical and dental applications. They are biocompatible, bioresorbable, and replaced by new bone when implanted in vivo[l,2]. However, the use of HCPC might impair the biocompatibility due to low or high pH values during setting. Therefore, the importance of composition on the respective pH profiles of the cement samples during setting and mechanical properties of the HCPC was investigated in this study.

    The Effect of Sodium Fluoride Solution on the Hydrolysis of CaHPO4·2H2O and the Solubility of Its Hydrolysate
    FENG Zu-De, CHEN Fei, LIN Chang-Jian
    2000, 21(S1):  302-302. 
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    Calcium hydrogen phosphate (CaHPO4·2H2O, DCPD) is one of the main inorganic components of bone and teeth[1]. Since the anticaries effect of fluoride was found in 1940's, much effort was made in the aspect of the fluoridation of HAP[2].However, the effect of fluoride ion on the solubility of DCPD remains unclear. This study investigated the hydrolysis characteristic of DCPD in NaF solutions and the solubility of the hydrolysates.

    Preparation of Yttrium Aluminum Garnet Powders by Modified Alkoxy-derived Process
    ZHAO Feng-Ying, ZHOU Jian-Guo, ZHAO Bao-Lin, YANG Lin, LI Wu-Ju
    2000, 21(S1):  303-303. 
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    Three compounds exist in the system Al2O3-Y2O3:yttrium aluminum garnet (YAG, Y3Al5O12), yttrium aluminum perovskite (YAP, YAlO3), and yttrium aluminum monoclinic (YAM, Y4Al2O9)[1]. Among these compounds, YAG has received the most attention due to its good optical properties. Single crystal YAG is best known as a solid-state laser host material.

    Chemistry in Surface Science
    Radial Gradient-index Glass Prepared by the Sol-gel Process
    ZHOU Jian-Guo, ZHAO Feng-Ying, ZHAO Bao-Lin, LI Wu-Ju, RUAN Shen-Kang, SU Mian-Zeng
    2000, 21(S1):  304-304. 
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    A glass rod having a continuous variation of refractive index in either the radii or axial di-rection is called the gradient-index (GRIN) glass. The GRIN materials are used for lens systems for compact copiers, etc, and are expected to be applied to the more complicated systems such as cameras,binoculars and so on[1].However, the application of GRIN lens is limited by the availability of only a few varieties. Although a large number of designs using GRIN elements are available for cameras, microscopes providing better imaging,practical fabrication is difficult due to the non-availability of GRIN lenses in various refractive index ranges.

    Chemistry in Materials Sciences
    The Influence of Heat Treatment Mode on the Properties of Bi4Ti3O12 Thin Films by Chemical Solution Deposition Technique
    XIAO Zhuo-Bing, CHEN Shang, YAO Jun, WU Zhu-Qing, WU Xian-Ming
    2000, 21(S1):  305-305. 
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    Bi4Ti3O12 thin films were prepared by chemical solution deposition technique on n-Si(lOO). Bismuth nitrate and titanium butoxide were used as starting materials. In this paper, we used this technique to prepare Bi4Ti3O12 thin films heat treated by both rapid annealing for 30 seconds in a rapid annealing heater and annealing in a furnace for 30 minutes, and found that the heat treat mode greatly influences the properties of the films. The crystallization temperature of the film made from rapid annealing is about 500℃, while that of the film prepared by heating in a furnace is about 550℃. X-ray diffraction pattern of the film heat treated by the former has stronger (004), (006), (008), (0010) peaks than that of the film heat treated by the latter, which suggests that the rapid annealing heat treat mode favors preferential c-oriental film. The grain size of the film obtained by rapid annealing is smaller than that of the film prepared by heating in a furnace. When the films were both annealed at 600℃,the coercive field of the film heat treated by the former is 45 kV/cm, while that of the film heat treated by the latter is 87 kV/cm.

    Vanadium-based Mixed Oxides Prepared from Thermal Decomposition of Citratorvanadium(IV) Precursor
    GAO Gui-Ying, FANG Zhi-Min, JIANG Ya-Qi, ZHANG Hui, MAO Shao-Yu, ZHOU Zhao-Hui, WAN Hui-Lin
    2000, 21(S1):  306-306. 
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    Citrate method is broadly used for the preparation of mixed oxides and their highly dispersive pure phases[1]. Up to now, most of the mixed oxides are prepared from putting the related chemical compounds together and sintering the mixture at high temperature, while the complexes formed during this process are uncertain. This will limit the design of high dispersibility and the purities of the resulted mixed oxides. Vanadium-based oxides are catalysts used in the partial oxidation of propane and butane. It has been demonstrated previously that the vanadium citrate complex with well-defined composition and structure is the better precursors for the preparation of V-based mixed oxide[2], Using the precursor of barium dimeric(citrato) oxovanadium(IV) tetrahydrates Ba2[VO(cit)]2·4H2O, barium pyrovanadate may be prepared with pre-determinated compositions and higher purities from thermal decomposition of the well-defined complexes at lower temperature.

    Synthesis of Silicone Modified Acrylic Resin Paint and It's Properties Studies
    ZHANG Wu-Long, CHENG Si-Kun
    2000, 21(S1):  307-307. 
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    An acrylic resin coating by itself, shows resistance to weather and color retention, but has poor high-temperature resistance. The silicone resin exhibits excellent weatherability, good heat resistance and strong hydrophobicity. To improve the exterior durability, dirt-pickup resistance and color retention of acrylic resin, a little amount of silicone functional group was introduced into it, taking advantaging of high dissociation energy and low surface tension, good stability to gloss and heat,ultraviolet light resistance of the Si-O bond of polysilonxane[1,2].

    The Electrochemical Behavior of Polypyrrole under Ultrasound
    ZHAO Chong-Jun, WANG Hai-Hong, JIANG Zhi-Yu
    2000, 21(S1):  308-308. 
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    Polypyrrole (PPy) is one of the most important conducting polymers. It has been widely studied for the uses of chemical sensors, electrocatalysis, rechargeable batteries and protective layers on semiconductor electrodes[1].

    Preparation of Spinel LiMn2O4 by a Spray-drying Method
    WAN Chuan-Yun, NULI Yan-Na, JIANG Zhi-Yu
    2000, 21(S1):  309-309. 
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    Spinel LiMn2O4 has already become an attractive cathode material for rechargeable lithium-ion battery. Compared with other layered compounds LiCoO2 and LiNiO2,LiMn2O4 offers several advantages:inexpensive, nontoxic, abundant and easy to prepare. These characteristics induce many researchers to study it to make it commercialized.

    Electrochromic Properties of Rhodium Oxide Films Prepared by Sol-gel Method
    WANG Hai-Hong, ZHAO Chong-Jun, JIANG Zhi-Yu
    2000, 21(S1):  310-310. 
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    Electrochromic materials have been extensively investigated for their significant potential in information display, automotive, sensor and smart windows[1]. Many studies have been carried out on the inorganic electrochromic materials, such as WO3, MoO3, NiOx and so on[2]. In this paper, We first report the electrochromic behavior of rhodium oxide film prepared by sol-gel method on transparent conductor substrate. The film exhibited reversible two color (from bright yellow to dark green) electrochromic behavior with satisfactory contrast at anodic and cathodic forms when the applied potential was reversed successively.

    The Diffusion Coefficient of Lithium Ions into Highly Oriented Pyrolytic Graphite
    NULI Yan-Na, WAN Chuan-Yun, JIANG Zhi-Yu
    2000, 21(S1):  311-311. 
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    The diffusion coefficient of lithium in graphite is an important parameter for the use of graphite because it relates to the ability of charge and discharge rate of lithium battery. It remains a problem that there are often obvious differences among the diffusion coefficients obtained using different methods, even in one paper[1,2]. This difference may attribute to the complicate properties of intercalation process, as well as some uncertain parameters of the porous structure electrode. In order to measure the diffusion coefficient of lithium in carbon more precisely, a well crystallized material Highly Oriented Pyrolytic Graphite (HOPG) was used as the material of working electrode in this study.

    The Iodimetric Value Measurement of Expanded Graphite
    LI Ji-Hui, LI Mei, HU Hai-Ying
    2000, 21(S1):  312-312. 
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    The shape of expanded graphite is a netted and hollow structure.It is very easy to adsorb molecules and adsorption power is better. The research has proved:the expanded graphite had its ability to adsorb weigh oil etc. The capacity of adsorptive materials has been expressed by the iodimetric adsorption value, but the iodimetric adsorptive value of expanded graphite has not been reported until so far.The paper measures the iodimetric adsorption value by the iodimetry, and the apparatus is used easily and simply. The operation is not more difficult and the accuracy is higher, and the reagent is usual.

    Chemistry in Surface Science
    A New Preparation of Lower-sulfur Content and Expandable Graphite by Oxidant
    HU Hai-Ying, LI Mei, LI Ji-Hui
    2000, 21(S1):  313-313. 
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    Expandable graphite is an excellent material. It has some marvelous character, such as, resistance to alkali and acid, resistance to heat and compression, resistance to draw and radiate, etc. Flexible graphite produced from the expandable graphite were used as an adsorbing material, storing hydrogen, catalyzing chemical reaction and so on.

    Chemistry in Materials Sciences
    Polymerization of Styrene by Thermal Scission of C-C Bond
    JIN Jing, WANG Hai-Sheng, WU Long-Min, ZHANG Zi-Yi, HUANG Hong-Jun
    2000, 21(S1):  314-314. 
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    A radical induced polymerization of syrene (St) with diethyl-2, 3-dicyano-2,3-diphenylsuccinate (1), producing ultra high molecular polystyrene wasreported herein. The polymerizations of syrene with dl-1 at 70-90℃ are shown in Figure 1. In this case, M of polymers was observer to in crease with reaction time.

    Hydrogenation Activity of Soybean Oil on the Amorphous Ultrafine NP Catalyst
    QIN Zhen-Ping, LI Dong-Sheng, ZHAO Qiao-Mei, YANG Wen-Xuan
    2000, 21(S1):  315-315. 
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    It has been reported that the hydrogenation of benzene, styrene, higher fatty acid etc,by use of the amorphous ultrafine alloy[1,2], which has shown higher hydrogenation activity. The hydrogenation property of soybean oil, seldom reported, was investigated in this paper.

    The Synthesis and Performance of SAPO-11 Molecular Sieve for Hydroisomerization
    LIU Hong-Jiang
    2000, 21(S1):  316-316. 
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    Hydroisomerization of n-paraffin to obtain branched chain paraffin plays an important role in producing high octane number gasoline blending component, improving low temperature performance of diesel and producing HVI lubricant oil. Mesoporous molecular sieve SAPO-11 that has proper acid strength and good shape selectivity show excellent catalytic performance on hydro-isomerization.

    Landfill Leachate Treatment by Hybrid Membrane Processes
    HE Xu-Min, CHEN Shao-Hong, ZHOU Hua, XIA Hai-Ping, LAN Wei-Guang
    2000, 21(S1):  317-317. 
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    Recent years, the treatment of landfill leachate has attracted increasing attention, in which the anaerobic-aerobic method is widely used in China, however, this method can not satisfactorily reduce the negative impact on the environments[1,2] and new effective methods of the treatment need to be developed. The membrane method is considered to be a feasible technique, we have used a hybrid technology of flocculent sedimentation-UF-NF-NF (Figure 1) in a pilot-plant unit to treat two types of Landfill, one from Zaihou landfill site in Xiamen, while the other from Jimei dunghill plant in Xiamen.

    Water-alcohol Separation by Pervaporation through Zeolite Modified Poly(amidesulfonamide)s (PASAs)
    HE Xu-Min, CHEN Wing-Hong, NG Ching-Fai
    2000, 21(S1):  318-318. 
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    A series of poly(amidesulfonamide)s (PASAs) which have been synthesized in our laboratory possess good membrane fabrication properties[1]. The potential use of these membrane materials in RO, UF and PV were demonstrated[2,3]. Reminiscent to the PV performance of other glassy polymers, most of these materials exhibit a fairly high separation factor albeit a permeation flux below 35 g m-2 h-1 in the PV separation of aqueous alcohol mixtures. To have a real application prospect in PV, the permeation flux through the membranes has to e further improved. The present work represents our effort to upgrade the separation characteristics of PASAs by blending with inert hydrophilic zeolites. Three types of PASAs (structure shown in Figure 1) were selected to be fabricated by blending different amount of zeolite NaA or NaX. The zeolite filled membranes were characterized by SEM, IR spectroscopy, sorption measurements and wide-angle X-ray diffraction. By adding proper amount of NaA into the polymer casting solutions, the resultant zeolite filled membranes exhibited improvement in both selectivity and permeability in the separation of 10% aqueous solutions of ethanol, propan-l-ol and propan-2-ol, as compared to the zeolite free membrane (Table 1).

    Studies on Adsorption Property for Metal Ions of Carboxymethyl Chitosan
    LIN You-Wen, CHEN Wei, LUO Hong-Bin, LI Chun-Yan, LIN Xin-Hua
    2000, 21(S1):  319-319. 
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    Chitosan is a polymer, which contains β-1, 4-linked α-amino-2-deoxy-D-glucopyranose repeat units and is easily derived from chitin by N-deacetylation. Since chitosan is biodegradable, relatively nontoxic, nonimmunogenic, much research has been directed toward its use in medical applications[1].It also has been suggested for use as chelating agent for metals, since the primary amino group and hydroxyl functionalities at the ring[2]. Chitosan is only soluble in aqueous solution of some acids, so it becomes a limitation. The carboxymethyl chitosan (CMCS),a water-soluble derivative of chitosan, was synthesized by chemical modification with ClCH2COOH and chitosan[3]. It was amphoteric polyelectolyte with stronger chelating ability for metals because of introduction of-COOH.

    Synthesis and Photocatalytic Activity of HTaWO6/(Pt,TiO2) Nanocomposite
    WU Ji-Huai, Tsugio Sato, YIN Shu, LIN Jiang-Ming, HUANG Miao-Liang
    2000, 21(S1):  320-320. 
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    Photoelectrochemical process at semiconductor interface has aroused special attention, because of its possible application for the conversion of solar energy into chemical energy. It is to be expected that the photoactivity of semiconductor is improved by incorporating in the interlayer of a lamellar compound.

    NMR Study of Pore Surface and Size in a Mesoporous Material FSM-16
    XIE Xiu-Lan, HAYASHI Shigenobu
    2000, 21(S1):  321-321. 
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    Surface structure, pore size distribution and pore wall thickness of a mesoporous material FSM-16 have been studied by X-ray powder diffraction (XRD), lH and 29Si MAS NMR and 1H liquid-state NMR, and by applying surface silylation as a probe. Concentrations of surface hydroxyl groups for FSM-16 are estimated from 29Si and 1H MAS NMR, which are about 3×l021 g-1, corresponding to approximately 3 nm-2. O2 molecules contribute to 29Si spin-lattice relaxation of Q2 and Q3 as well as Q4, suggesting thin wall thickness. 1H MAS NMR spectra indicate the presence of isolated and hydrogen-bonded hydroxyl groups. Both hydroxyl groups are silylated, where the silylated fraction is about 50%. The spatial distribution of surface hydroxyl groups is estimated from the line width in 1H static spectra. A rather homogeneous distribution is demonstrated in one of the samples. The sample with less homogeneous distribution has a larger affinity for moisture. Pore size and pore wall thickness were determined by 1H NMR measurements on water saturated FSM-16 samples, which are in good agreement with literature values obtained by N2 adsorption isotherms and transmission electron micrographs on a similar sample. In benzene saturated samples, a non-freezing surface layer of benzene is much thicker than that of water, which indicates a stronger interaction between benzene and the FSM-16 surface.

    Trial Test of Supported Nanosized Catalyst in Catalytic Reformate Hydrotreating Reaction
    HE-Jin, PANG Hong, NAN Jun
    2000, 21(S1):  322-322. 
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    Nanostructured particles are a new kind of materials whose size is less than 100 nm. It is obvious that the properties(e.g. electronic, magnetic, catalytic, optical and themal etc) of nano-particles are more excellent than those of traditional materials because of high specific surface area and special structure. Up to now, nano-particles have been studied and will be developed as a new kind of catalysts in the oil and chemical industry as well as environment protection fields. In this paper, catalytic properties of the nano-Pd/Al2O3 catalyst were studied for catalytic reformate hydrotreating reaction.

    The High-spin↔Low-spin Equilibrium of Iron(Ⅱ) Complexes with Schiff Base Ligand:Optical, Magnetic and Spectroscopic Properties
    WANG Hong-Mei, CHENG Peng, LI Li-Cun, LIAO Dai-Zheng
    2000, 21(S1):  323-323. 
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    Spin transition compounds are of great interest because of their potential application in molecular based electronic devices such as optical memoty and switch, display and data record[1]. The occurrence of iron(Ⅱ) spin crossover systems depends on the ligand field strength. Iron(Ⅱ) spin crossover compounds mainly have sixfold nitrogen coordination and the range of lODq is very narrow:10DqHS≈11500-12500 cm-1 and 10DqLS≈19000-21000 cm-1[2]. The sensitivity of the spin state to small perturbations suggests that new coordination complexes exhibiting spin transition phenomena could be designed through a fine tuning of the ligands surrounding the metal. The derivatives of 1,2,4-triazole have been found to generate an intermediate ligand field force and the iron(Ⅱ) compounds containing such ligands which yielded spin-crossover materials exhibiting cooperative behavior have been reported recently[3]. In this paper we present two new iron(Ⅱ) compounds FeL3(ClO4)2·2H2O (1) and FeL3(BF4)2·3H2O (2),where L is the Schiff base ligand derived from 4-amino-l,2,4-triazole and benzaldehyde. The compounds appear as white (HS) powders at room temperature and the color changes to pink (LS) upon decreasing the temperature to liquid nitrogen. 1 and 2 are investigated by the optical setup (520 nm, 293-77 K), 57Fe Mössbauer Spectroscopy (293-77 K) and magnetic susceptibility (293-4 K). The HS→LS and LS→HS transitions were observed at Tc↓=135 K (1) and 169 K (2), and Tc↑=150 K (1) and 180 K (2), respectively. The thermal hysteresis is found to be 15 K and 11 K for 1 and 2. The area fractions are calculated to be 57% for 1 and 43% for 2. Variable temperature magnetic susceptibility data were fitted to magnetic susceptibility equations derived from domain model, two level Ising-type model and regular solution model. The calculated variations of enthalpy and entropy of the compounds fall within the limits ΔH≈8.1-10.9 kJ·mol-1 and ΔS≈47-61 J·K-1·mol-1 found for mononuclear iron(Ⅱ) spin transition compounds from calorimetric measurements. The cooperativity parameter y determines the occurrence of hysteresis.

    Biosorption of Cadmium by Phanerochaete Chrysosporium
    LI Qing-Biao, LIU Gang, HU Yue-Lin, DENG Xu, WU Yuan-Fei, SUN Dao-Hua
    2000, 21(S1):  324-324. 
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    The biosorption properties of cadmium(Ⅱ) by pre-treated biomass of Phanerochaete chrysosporium in the form of pellet were investigated. It was found that formaldehyde cross-linking and subsequent alkaline treatment could significantly improve the adsorption capacity of the biomass compared to other sorts of treatments, such as calcium chloride treatment, HCl treatment and,acetone treatment. Biosorption capacity of cadmium was examined as a function of physical and chemical factors including the pH of the metal solution pellet size, temperature and biomass concentration. The cadmium removal efficiency was strongly affected by pH. The maximal adsorption occurred around pH4.5. The pellet size also had a marked influence on the cadmium removal efficiency and the optimum size was the diameter range of 1.5-2.0 mm. The effect of biosorption temperature on cadmium uptake was inconspicuous between 25℃ and 35℃, but there was a notable decrease in cadmium uptake when the temperature reached 40℃. The cadmium removal efficiency increased as the biomass concentration when the initial cadmium ion concentration was 10 mg/L. When the biomass concentration was 2 g/L,the removal efficiency was 99.56%. However, the augment of the. removal efficiency was not obvious when the biomass concentration was more than 2 g/L. On the optimum conditions mentioned above,cadmium concentration could be reduced from 10 ppm down to 0.04 ppm that was below the Chinese National Waste Water Integrated Discharge Standard. In the biosotption process, most of the metal uptake happened during a short period immediately after the adsorption process started. It was observed that the biomass pellets had already adsorbed 83.36% of the total amount of cadmium finally adsorbed within the initial 10 minutes. The cadmium uptake rate decreased gradually afterwards. Sorption equilibrium could almost be established in 12 hours. This indicated that biosorption might consist of two processes:a fast surface binding process opcurring first and a slow membrane diffusion process taking place subsequently.

    Preparation of Activated Carbon from Sawdust by ZnCl2 Activation
    YE Li-Yi, ZHANG Hui-Ping, YANG Li-Chun, ZHANG Sheng-Yu
    2000, 21(S1):  325-325. 
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    Activated carbon is a remarkable adsorbent with high specific surface area and adsorption capacity, and has been widely used in industries and environmental protection. How to develop new type techniques of activated carbon production and prepare high adsorption capacity products are important.

    Anaerobic Fermentation Treatment of Bagasse Alkaline Spent Liquor
    YE Li-Yi
    2000, 21(S1):  326-326. 
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    The bagasse is the waste of sugar-making industry, it contains 50% of cellulose and is the major material of pulp and paper industry in Guangdong, Guangxi, Fujian, Sichuan provinces. In industry, the bagasse chemical pulp is often made by using alkali, most of bagasse pulp mills without recovery of soda and organic materials, and are discharged into the river because of technologic and economic reason. This makes serious pollution to the water and affects the ecological balance.

    Self-assembly of an Unprecedented Cynao-bridged One-dimensional 4f-3d Complex[Eu(DMF)4(H2O)2Cr(CN)6] H2O
    KOU Hui-Zhong, GAO Song, YU Kai-Bei
    2000, 21(S1):  327-327. 
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    Recently, there has been considerable interest in cyano-bridged lanthanide(Ⅲ) hexacyanometalate(Ⅲ) complexes LnM(CN)6·nH2O (M=Fe, Cr and Co) because of their potential as catalytic, semiconductive, and magnetic materials.[1-8] In this study, we employed N,N-dimethylformamide (DMF) as a hybrid ligand to construct a bimetallic complex[Eu(DMF)4(H2O)2Cr(CN)6]·H2O. It was synthesized as yellow crystals by the self-assembly of anhydrous EuCl3 and (Bu4N)3[Cr(CN)6] in MeOH and DMF. Single-crystal X-ray diffraction analysis shows that it consists of a cyano-bridged chain structure. The Eu atom is eight-coordinate with a distorted bicapped square antiprism geometry. Six oxygen atoms of two water molecules and four DMF molecules and two nitrogen atoms of the bridging CN ligands are bound to Eu with the Eu-O distance ranging from 2.368(7) to 2.447(8) Å. The bridging cyanides coordinate to the Europium(Ⅲ) ion[N(l)-Eu=2.543(9) Å and N(3)-EuA=2.543(8) Å] in a bent fashion with the bond angles of 164.0(9) for C(1)-N(1)-Nd and 155.1(7)。for C(3)-N(3)-EuA (A denotes the symmetry transformation:-x+l,y-l/2,-z+3/2). Each Cr(CN)6 coordinates to two Eu(Ⅲ) ions using two cis cyanide ligands, while each Eu(DMF)4(H2O)2 group connects two Cr(CN)6 moieties in a cis fashion, giving rise to an unprecedented chain structure. Crystal data:monoclinic, space group P21/c, a=13.151(2), b=12.905(2), c=19.186(2) Å, β=109.70(1)°, V=3065.5(7) Å3,Z=4, ρobs=1.531 Mg m-3, S=1.024,R1=0.0540, Rw=0.1616.

    Lanthanide and Transition Metal Coordination Polymers via Hydrothermal Reaction
    CAO Rong, LIANG Yu-Cang, HONG Mao-Chun, SU Wei-Ping
    2000, 21(S1):  328-328. 
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    Studies on the syntheses, structures and properties of lanthanide-transition metal complexes are of current great interest, because they can provide good models for investigation of the nature of magnetic exchange interaction between 3d and 41metal ions in the magnetic materials containing rare earth metals. Many of such studies were focused on discrete complexes which were synthesized from the conventional self-assembly reactions in solution. Although several infinite lanthanide-transition metal complexes containing organic ligands have been obtained by conventional solution synthetic method, the polymeric complexes have been poorly explored. Recently we try to use organic ligands for designing magnetic complexes comprising lanthanide and transition metal ions, especially Gd-Cu, Gd-Zn and Gd-Ag couple,with infinite structures, and hope to provide useful messages for the modeling of the magnetic exchange in magnetic materials. Herein reported are a series of lanthanide and transition metal polymeric complexes[{Gd2M3(pydc)6(H2O)12}·4H2O]n and[{Gd4M2(pydc)8(H2O)12}·4H2O]n (M=Cu, Ag,Zn) with 1D chain and 3D wave-like structure, which were prepared from the hydrothermal reactions of Gd2O3, pyridine-2,5-dicarboxylic acid (H2pydc) and Zn(OAc)2 or MO, respectively.

    Chemistry in Surface Science
    What Happens Structurally when one OH- Group in Co(OH)2 is Replaced by one -CO2- Group?
    HUANG Zhong-Le, MASCIOCCHI Norberto, SIRONI Angelo
    2000, 21(S1):  329-329. 
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    Inorganic-organic hybrid materials are particularly in focus in the past few years for both chemists and physicists, because of their structural characteristics quite different from those of coordination chemistry and solid state chemistry. Such materials may be of great interest to both fundamental viewpoint and potential applications in the areas of catalysis, sorption, photochemistry, electrochemistry, magnetism, or even multi-property.

    Chemistry in Materials Sciences
    Influence of Saturated or Unsaturated Dicarboxylate Anions on Magnetism of Co(Ⅱ) and Cu(Ⅱ) Hydroxide-based Spin Layers
    HUANG Zhong-Le, RABU Pierre, DRILLON Marc
    2000, 21(S1):  330-330. 
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    In the context of molecule-based magnets, a driving force is the design of complex systems, combining molecular units used as building blocks, to favor bulk magnetic properties. Such a strategy has been successfully explored for the preparation of both purely organic as well as purely inorganic magnets. A step forward, to achieve multifunctional solids, is the combination of both the molecular and inorganic chemistries to build hybrid organic/inorganic materials. Clearly, such an approach is very appealing for the design of novel 3d materials exhibiting improved properties with respect to those of the individual networks.

    Crystal Chemistry of Ternary and Quaternary Transition Metal Nitrides
    HUANG Zhong-Le, RAINER Niewa, RUDIGER Kniep
    2000, 21(S1):  331-331. 
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    Nitrides are fascinating materials. Although the air we breathe is 78% nitrogen, essentially 100% of the land we walk upon are made of oxides. It would take an encyclopaedia to review oxide crystal chemistry, on the other hand we can present here a comprehensive review of ternary and quaternary solid state nitrides. In the ternary and quaternary solid state nitrides (IA,IIA)-M-N, unusual low valence M+ were found for copper, nickel, cobalt, iron and manganese, and various MNn transition metal-nitrogen coordination polyhedra with CN=2(linear), 3(trigonal-planar), 4(tetrahedral and square planar), 5(square pyramidal), and 6(octahedral and trigonal prismatic) and different fashions of connection make nitrides an important family of inorganic solid state materials. A suitable classification is made on the basis of the correlation between coordination numbers (CN), the connection fashions and oxidation states of the anionic principal structures.

    Unusual Monovalent Transition Metals (M=Cu, Ni, Co, Fe, Mn, and Cr) Stabilized in Nitrides Li2(Li1-xMx)N with Chain Structure
    HUANG Zhong-Le, RAINER Niewa, RÜDIGER Kniep
    2000, 21(S1):  332-332. 
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    Chain compounds often exhibits specific physical phenomena owing to interactions between repeating units in one dimension alone. The simple topology of a chain allows more easily to establish chemical correlations between structure and properties.

    High Regioselective Hydroformylation of Higher Olefins Catalyzed by Water-soluble Rhodium Complex
    CHEN Hua, ZHANG Shou-Chun, LI Yao-Zhong, LI Rui-Xiang, CHENG Pu-Ming, LI Xian-Jun
    2000, 21(S1):  333-333. 
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    The idea of two-phase (aqueous/organic) catalysis has attracted great attention in recent years due to the easy separation of catalyst from organic products by simple decantation and the environmental benefits. However, in the case of higher olefin hydroformylation, the unacceptable low reaction rate was observed due to its very low solubility in water. In fact many efforts have been devoted during the last years to find efficient means either to improve the mass transfer of the reactants or to maintain the active species at the interface, mainly by using a co-solvent, a cyclodextrin, a surfactant, an amphiphilic ligand, a carbohydrate modified phosphine or by supported aqueous phase catalysis and water-soluble polymer ligand.

    Synthesis and Structure of Hetropolyoxometal-supported Transition Metal Complexes
    YU Rong-Min, CHEN Jin, LU Shao-Fang, LU Can-Zhong
    2000, 21(S1):  334-334. 
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    The chemistry of metal-oxo compounds has been extensively and intensively studied for over a hundred years because of their theoritical importance and practical application[1]. Recent advance has afforded a study of inorganic or organometallic complexes containing metal-oxo anions[2]. Herein, the synthesis and structural characterization of two heteropolyoxomolybdnum-supported transition metal complexes (H2bpy)0.5Ni(H2O)5[Mo5P2O23]Ni(Hbpy)(H2O)4 (1) and (H2bpy)0.5Co(H2O)5[Mo5P2O23]Co(Hbpy) (H2O)4(2) are reported.

    Structural Characterizations of Spherical Octadecavanadates Encapsulating Na+, K+ or I- and Ellipsoidal Octadecamolybdate Encapsulating two Anions of SO42-
    ZHU Hong-Ping, CHEN Chang-Neng, CHEN Yi-Hui, LIU Qiu-Tian
    2000, 21(S1):  335-335. 
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    Polyoxoanions of tungsten, molybdenum, and vanadium have been the subject of interest since their wide variety of compositions, structures, and properties give rise to numerous important applications[1]. From the NH4VO3/Na2Sx (or (NH4)2Sx) reaction system we synthesized several spherical octadecavanadates with Na+,K+, NH4+ or I encapsulated using hydrothermal method. These complexes include (NH4)11[V18O42(Na)]·(H2O)20 1; (NH4)11[V18O42(K)]·(H2O)6, 2; (NH4)10(Na)[V18O42(Na)]·(H2O)26, 3; (NH4)11[V18O42(NH4]·(H2O)20, 4; and (NH4)20(I)7[V18O42(I)]·(H2O)12, 5, in which the structures of 1, 2, 3, and 5 have been determined by X-ray analyses. In the analogous reaction system of (NH4)2MoS4/(NH4)2Sx, we also obtained one ellipsoidal octadecamolybdate, (NH4)4[Mo18O54(2SO4)]·(H2O)4, 6 with a standard Wells-Dawson structure[2]. The Ortep drawings of the two kinds of structures are viewed as follows.

    Unusual Stepwise Assembly of a New Polymolybdate with Novel Building Blocks:Li12[H16Mo36O108]·48H2O
    WU Chuan-De, LIN Xiang, YANG Wen-Bin, LU Can-Zhong, ZHUANG Hong-Hui
    2000, 21(S1):  336-336. 
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    Molybdenum in its higher oxidation states is easy to form poly-nuclear anionic metal-oxygen clusters, many giant polymolybdates with extraordinary variety of the relevant topology and electronic structures were reported [1].As the mechanism of the formation of complex molecular systems from simple building blocks by conservative self-assembly process is currently the subject of intense research but not yet fully understood, the synthesis of goal compound is still elusive.

    CO/CO2 Hydrogenation to Methanol over Cu-ZnO/CNTs Catalyst
    DONG Xin, CHEN Shu-Gui, ZHANG Hong-Bin, LIN Guo-Dong
    2000, 21(S1):  337-337. 
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    Carbon-nanotubes (CNTs), one type of tubular carbon-nanofibers, as a novel material of catalyst carrier, are drawing increasing attention recently1' This kind of new nanocarbon-material possesses some peculiarities, i.e., its nanochannel and the tube-wall with graphite-like structure, which make carbon-nanotubes expectable to be a novel material of catalyst carrier[2,3]. In the present work, CNTs-supported Cu-ZnO catalyst were prepared, and its catalytic properties for CO/CO2 hydrogenation to CH3OH were investigated and compared with those of the Cu-ZnO systems supported by γ-Al203, silica-gel (SiO2) and active carbon (AC). The results have significance for revealing the nature of promoting action by CNTs carrier.

    Ferritin as a Novel Catalyst for Selective Hydroxylation of Phenol
    ZHANG Ning, LI Feng-Yi, TSANG S.C.J
    2000, 21(S1):  338-338. 
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    Ferritin molecule consists of a spherical polypeptide shell (apoferritin) surrounding a nanometeric inorganic core of iron oxide ferihydrite. It has the ability to sequester and store iron in a bio-available form by mobilizing or immobilizing iron through its narrow channels in the stable polypeptide quaternary structure[1,2].Our original idea was to explore the catalytic activity of the inner nano-sized, iron oxide core. It was also hoped that the spherical hollow polypeptide shell with channels might act as a biological-molecular, sieve, displaying some kinds of shape and size selectivity.

    Instrument for Manipulating and Transporting Micro-particles in Liquid Phase
    HU Yong-Gang, HU Rui, SHAO Han-Juan, CHEN Mu-Zhuan, TIAN Zhao-Wu
    2000, 21(S1):  339-339. 
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    More and more peoples begin to care for the ability to manipulate and transport single micro-particles such as cells, subcellular organelles and macromolecules for the purpose of study in biochemistry, biology, molecular medicine and molecular assemblies etc. According to the reports, the main methods for manipulating micro-particles in liquid phase are optical tweezers[1], electrophoresis[2] and suction syringe[3]. However, they are many shortcomings by using these methods mentioned above,for example, optical tweezers would lead to optical matter, electrophoresis method would lead to electric matter when the particles placed in the field, and the method of suction is difficult to reach automatization. Here, according to the theory of electroosmosis pump, a novel instrument so-called electro-micromanipulator developed in our laboratory for manipulating or transporting single micro-particles in liquid-phase is introduced. This electro-micromanipulator isolated the sample from electric field so that it could avoid the shortcomings of methods mentioned above. Finally, this instrument has been demonstrated for manipulate and transport different size single alga cells successfully,more research works of manipulating and transporting DNA macromolecules for study in biochemistry, biology, molecular assemblies etc are going on.

    A Novel Application of Capillary Electrophoresis for Evaluating the Mutation Effects of Stevia Induced by Ion Implantation
    HU Yong-Gang, SHAO Han-Juan, HU Rui, CHEN Mu-Zhuan
    2000, 21(S1):  340-340. 
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    Stevia rebaudiana is a member of the Compositae, native to Paraguay. It produces a number of high-potency low-carlorie sweeteners in its leaf tissue. The sweeteners are diterpene glycosides and range between 30 and 320 times sweeter than sugar. Therefore, Stevia is likely to become a major source of high-potency sweetener for the growing natural food market in the future. Generally, techniques of ion implantation have been used to treat plant seeds and induce mutation for increasing the produce of stevia sweeteners. Various methods for analysis products of stevia rebaudiana have been reported, including gas-liquid chromatography, thin-layer chromatography and HPLC etc. However, these methods are time consuming. The separation and determination of stevia sweeteners by capillary electrophoresis was successfully demonstrated recently[1,2].

    Study of Competitive Chelating Reaction between Lanthanum and Tribromoarsenazo in the Medium of Weak acid by Capillary Zone Electrophoresis
    HU Yong-Gang, ZHOU Pei-Jiang, DENG Yan-Zhuo, CHENG Jie-Ke
    2000, 21(S1):  341-341. 
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    Study of chelating reaction in solution is one hot and difficult field in coordination chemistry, and HPLC and CE have been used to study the kinetics of fast equilibrium in this field successfully. However, these methods are used for studying relative simple reaction systems presently[1-3]. This-paper describes a new application of CE for studying complication competitive chelating reaction in fluid-phase, which is difficult to be studied by conventional methods. Two kind metal chelate complexes of lanthanum reacted with TBA formed under the condition of critic acid were observed in real time by simultaneous technique of CE-PTI spectrometry. The tendency of the conversion between these chelates as functions of the mole ratio of the reagent and the metal, pH value and the elapsing time was investigated. Kinetic equation of competitive chelating reaction between the TBA-La (Ⅲ) and La (Ⅲ) -critic acid was established too. As shown in tablel, It was found this competitive chelating reaction following second-order reaction, and reaction constant k=5.55 L·mol-1·S-1.

    Preparation and photoelectrochemical characterization of nano-particulate TiO2 and polyaniline composite films on Au
    HUANG Huai-Guo, LUO Jin, ZHENG Zhi-Xin, WU Ling-Ling, LIN Zhong-Hua
    2000, 21(S1):  342-342. 
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    TiO2 and polyaniline(PANI) composite film was obtained by electrochemical methods[1] and investigated for solar energy conversion application. A strong rectifying effect was found in the cyclic voltammogram of the film in dark when the scan speed was slow enough (5 mV/s) and a quasi-reversible voltammogram of the film was observed when the scan speed was fast (100 mV/s). The results of both the cyclic voltammograms and the SEM images of the composite film show that the PANI film is almost completely covered with nano-particulate TiO2. Two anodic photocurrent bands and a cathodic band was observed in the spectra of the photocurrent of the TiO2/PANI/PATP(p-aminothiophenol)/Au film in 0.05 mol/L Fe(CN)63-/Fe(CN)64- solution. The band at 300~400 nm (3.1~4.1 eV) can be ascribed to the photocurrent band of TiO2 particles and the bands at 450~730 nm (1.7~2.8 eV) can be ascribed to those of the PANI. The partially-oxidized PANI has internal photoemission function and the insulating matrix of PANI is verified to be reduced PANI with a 3.33 eV bandgap energy. The flat-band potentials of partially-oxidized PANI and TiO2/PANI composite film in 1.0 mol/LHClO4 solution are determined as 0.87 V and 0.09(SHE) from Mott-Schottky plots, respectively.

    The Effect of Preparation Condition on the Photoelectrochemistry of PANI/PATP/Au Film and TiO2/PANI/PATP/Au Composite Film
    HUANG Huai-Guo, LUO Jin, ZHENG Zhi-Xin, WU Ling-Ling, LIN Zhong-Hua
    2000, 21(S1):  343-343. 
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    The polyaniline(PANI) film and TiO2/PANI composite film were obtained on different preparation conditions by electrochemical methods[1] and the photoelectrochemistxy of them were also studied. The self-assembling of p-aminothiophenol(PATP) favor the adhesion of PANI, and the longer time PATP self-assembled, the better adhesion of PANI has. After self-assembling PATP for 12 h, the adhesion of PANI drives to stabilization. There is an optimal thickness of PANI film for the photoelectrochemical response[2]. Fig. 1 show that the PAM of polymerizing 100 cycles in 0.5 mol/L aniline/HClO4 is optimal in our studies. The anodic and cathodic photocurrent bands of the pernigraniline (appeared within 1.45~2.8 eV), the emeraldine salt and the leucoemeraldine (both appeared within 1.7~2.8 eV) are observed in Fig. 2. The onset energy of the emeraldine salt is smaller than the value of 3~4 eV given by references, and obviously the subband gap photocurrent are obtained. And since the leucoemeraldine prepared by electropolymerization contains some emeraldine salt, the spectra of photocurrent for the leucoemeraldine is similar to that of the emeraldine salt except for much smaller IPCE. The onset energy of the pemigraniline (about 1.45 eV) is considerably consistent with theoretical calculation[3]. Though high temperature is in favor of the photoelectrochemistry of TiO2. But there is an optimum temperature because when the temperature is so high that the surface texture of PANI film will be damaged. We evaluated the power characteristics of a simple photoeletrochemical cell by employing different TiO2/PANI films as photoanode and a Pt wire as a counter electrode in 0.05mol/L Fe(CN)63-/Fe(CN)64- solution. The results show that the energy conversion efficiencies for the TiO2/PANI film dried under the temperature of room temperature, 100℃, 150℃, 200℃ with a white radiation of Xe lamp(150 W). are 2.4%, 3.3%, 3.9%, 2.8% respectively. In this paper, the temperature of 150℃ is the optimal temperature for heating TiO2/PANI composite film.

    Nano-organized CdS particles with Quantum Effect on Polyaniline Film
    HUANG Huai-Guo, ZHANG Hong-Ping, LUO Jin, ZHENG Zhi-Xin, WU Ling-Ling, LIN Zhong-Hua
    2000, 21(S1):  344-344. 
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    Polyaniline(PANI)/p-aminothiophenol(PATP)/Au film was obtained by electrochemical methods[1].The CdS nano-particles were electrodeposited according to the method of Baranski etal.[2].

    Chemistry in Surface Science
    Assembly of Organic Molecules on Solid Surface-A STM Study
    BAI Chun-Li
    2000, 21(S1):  345-345. 
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    Since the adsorbed organic molecules layers play a key role in the phenomena of lubrication, catalysis on surface, and construction of molecular devices, it is therefore keen to understand the structure and properties of the assembled organic molecules on surfaces.

    Simultaneous High Throughput Single Molecule Electrophoresis and Single Molecule Spectroscopy
    MA Ym-Fa, SHORTREED Michael R., YEUNG Edward S.
    2000, 21(S1):  346-346. 
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    Single molecule detection (SMD) has developed rapidly in recent years, especially high-throughput single molecule detection. Such research facilitated several fundamental studies at the single molecule level. In the fixture, SMD may be successfully applied to biological, clinical and medical research for DNA sequencing and single-molecule scans for disease detection. Presently, single-molecule identification of DNA and proteins is performed using fluorescence intensity, mobility or hybridization with a selective probe. In some cases, such methods are insufficient for confident single-molecule identification. Therefore, we invented a high-throughput combination single-molecule spectroscopy/imaging technique for monitoring the spectroscopic differences of several different individual molecules while they migrate in solution. The technique can offer three-dimensional data for each molecule:mobility, fluorescence intensity and spectroscopy information. Two sample systems were selected as test cases. In the first case, λ DNA is labeled with YOYO-Ⅰ,POPO-Ⅲ and a combination of the two dyes. Many individual λ DNA molecules are simultaneously imaged and identified by their spectroscopic differences. In the second case, a biotinylated 2.1 kb PCR product (also labeled with YOYO-Ⅰ) was reacted with avidin-conjugated R-phycoerythrin. The individual reactants and products are also simultaneously imaged and identified by their spectroscopic differences. This technique can be used for high-throughput DNA screening, molecular identification and monitoring intermolecular interactions with a speed of over 2,000,000 molecules per second. The existing method is the highest and most powerful single-molecule screening method available to date. Such technology is expected to have a great impact on single-molecule diagnosis and monitoring molecular interaction at the single molecule level and will be beneficial to early detection and diagnosis of disease (e.g. cancer, HIV). Furthermore, this technique allows one to directly observe and evaluate the data without any complicated calculations.

    Layer-by-layer Assembled Organic-Inorganic Hybrid Films:Preparation, Characterization and Applications
    LI Xiao-Yuan, WANG Bao-Xing, NIU Guo-Xing, CAI Li-Rong, YAO Gang
    2000, 21(S1):  347-347. 
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    Assembly of a multi-layered molecular film can be achieved by employing one or combination of several chemical forces, including covalent, coordinating, and electrostatic (including hydrogen-bond) linkages. In this report, we will present the study in our group on the molecular films prepared by alternatively assembling organic and inorganic layers in a layer-by-layer manner, and their applications in analytical chemistry and materials sciences.

    Surface Assembly and Molecular Electronics
    ZHU Xiao-Yang
    2000, 21(S1):  348-348. 
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    The use of molecules as electronic devices is one of the focuses in the emerging field of nanotechnology. Two issues of relevance to this topic will be discussed in this lecture. In the first part, I will discuss the interfacial electronic structure and electron transport mechanism at molecular-metal junctions. Recent results from my laboratory revealed the role of chemical anchor in electron transport and the formation of molecular quantum wells at metal/organic interfaces. In the second part, I will present a general strategy to integrate molecular components into silicon technology. The application of this chemistry beyond molecular electronics will also be discussed.

    Recent Advances in Recursive Solution of Large Molecular Eigenproblems
    GUO H.
    2000, 21(S1):  349-349. 
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    In studying highly excited ro-vibrational spectra of polyatomic molecules, the traditional direct diagonalization approach becomes impractical because of the formidable computational resources needed I will in this talk discuss some recent advances in solving large dimensional molecular eigenproblems using sparse matrix techniques. In particular, I will talk about the Lanczos algorithm and the Chebyshev-based filter-diagonalization method. These techniques are based on matrix-vector multiplication and thus amenable to larger problems. Applications to highly excited (ro-)vibrational spectra of tri- and tetratomic systems such as SO2 and HOOH will be presented.

    Theoretical Studies of Single Molecule Spectroscopy at Room Temperature
    CAO Jian-Shu
    2000, 21(S1):  350-350. 
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    This talk is motivated by recent room-temperature single molecule experiments, which measure the optical spectrum along single molecular trajectories and monitor the molecular dynamics and chemical kinetics of individual reactive systems. These experiments contain new information that requires theoretical models and interpretations. Several aspects of single molecule spectroscopy are analyzed:(1) Event-averaged single molecule quantities are calculated, with the prediction of the echo signal in the joint event probability distribution function[1]. Similar to the photon echo phenomenon, the single molecule echo signal measures solvent effects on chemical kinetics. (2) The statistics of single molecule blinking events are often correlated to underlying quantum mechanisms. The distribution functions of waiting-time sequences are examined for several quantum processes, including electron transfer, solvent relaxation, laser-induced emission, and single quantum-dot blinking[2]. (3) Single molecule measurements of heterogeneous diffusion reveal deviations from the Gaussian distribution of Brownian motion. As a quantitative measure, the non-Gaussian indicator decays asymptotically to zero according to 1/t for finite time correlation, but saturates at a plateau value for power-law correlation.

    Vapor Phase Epitaxy of Nitride Films
    ZHANG Rong, SHEN Bo, GU Shu-Lin, ZHOU Yu-Gang, CHEN Peng, LI Wei-Ping, CHEN Zhi-Zhong, LU Dian-Qing, CHEN Ke-Lin, ZHENG You-Dou
    2000, 21(S1):  351-351. 
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    GaN and related compounds are very promising materials for developing short wavelength light emitting devices, such as laser diode (LD) and light emitting diode (LED), high temperature and high power electronics. Commercially used nitride materials have been made by vapor phase epitaxy (VPE), including metalorganic vapor phase epitaxy (MOVPE) and hydride vapor phase epitaxy (HVPE). MOVPE is a widely used technique to fabricate semiconductor films. Its precise control of growth process, ability of handling multi large area wafers, and excellent reproducibility make it valuable in large-scale production of electronic and optoelectronic devices. VPE of nitrides has met several critical materials issues. Firstly, a high vapor pressure of nitrogen leads to the lack of bulk crystal of GaN. People have to use heteroepitaxy technique to produce GaN materials and devices, which makes high-density defects in GaN epilayers. Secondly, the high bonding energy of GaN and high stability of NH3 require a high growth temperature. The high nitrogen vapor pressure at high growth temperature requires enhanced local precursor densities. Additionally, the growth chemistry of VPE of nitride materials is very complicated. Parasitic chemical reactions take place during the VPE growth and degrade the material quality. Finally, the physical process of VPE growth has not been well understood. Optimized production of nitride material is predicated on an understanding of how the film properties are affected by the initial processing sequence. Heteroepitaxy of nitrides is strongly influenced by the initial nucleation and growth sequence.

    Nano-Patterning via Molecular Self-Assembly
    ZHANG Xi, ZHANG Li, ZOU Bo, XIONG Hui-Ming, SHEN Jia-Cong
    2000, 21(S1):  352-352. 
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    Surface patterning with microscopically defined structures is a rapidly developing topic, although it is still a challenge for generating patterned surface in the size range of nanometer. Molecular assemblies normally in the size range of 1 to 102 nm should overcome easily the conventional lithographic limit. Although many techniques have been developed to generate patterned surface, surface patterning totally directed by molecular self-assembly has been less addressed. For this purpose, ways of molecular self-assembly to generate regular arrays of nanostructures have been demonstrated in our laboratory including chemisorption of dendron-thiols,surface adsorption of bolaform amphiphiles, and nano-phase separation of rod-coil diblock molecules. As to be discussed, molecular self-assembly is an alternative but effective way to produce patterned structures, particularly in the range of a few nanometers.

    Applications of UY Resonance Raman Spectroscopy in Chemistry, Biology and Materials Sciences
    LI Can
    2000, 21(S1):  353-354. 
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    This paper reviews the recent advances in the UV Raman spectroscopy applied in catalysis, biology and materials sciences, and focuses on the spectroscopic characterisation of nano-structured materials, microporous and mesoporous catalysts and in-situ studies of catalysis under working conditions.

    A Novel Catalyst in N2O Decomposition-the Preparation of Cu, Co-exchanged Al-pillared Smectite and its Catalytic Activity
    XU Xiu-Feng, SUO Zhang-Huai, WEI Yu-Ping, AN Li-Dun
    2000, 21(S1):  355-355. 
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    Nitrous oxide(N2O) is now considered a greenhouse gas and contributes to catalytic stratospheric-ozone destruction. Therefore, the catalytic decomposition of N2O has become one of the urgent environmental issues[1-4].

    Photo-electrochemically Synergetic Effect in the Catalytic Degradation of Reactive Dyes
    AN Tai-Cheng, ZHU Xi-Hai, XIONG Ya
    2000, 21(S1):  356-356. 
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    The dye wastewater has a high potential environmental impact principally due to the wastewater containing high organic charge and strong coloration. As far as back the 1980s, the totals of synthesized dyes have been more than 800 thousand tons every year in the whole would. However, in the all of dyes, reactive dyes represent an important fraction of the commercialized synthetic pigments used. The major environmental problem associated with the use of the reactive dyes is their loss in the dyeing processes with general low fixation efficiency, large mount of dye-containing wastewater was inevitably discharged into water supply. So, the treatment of wastewater containing reactive dyes is very urgent for our health.

    The Preparation and Characterization of Several Metal Phosphate Catalysts
    MAO Jian-Xin, XU Yu-Zhan, DING Yun-Jie, LU Wei-Min, ZHENG Xiao-Ming
    2000, 21(S1):  357-357. 
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    Metal phosphates have been widely used as catalysts in many organic reactions for their acid-base and redox properties[1,2]. Their structure and properties are affected greatly by the preparation method[2-5]. AlPO4 is one of the most important metal phosphates. There are many different phases of AlPO4) that is, amorphous, crystalline and molecular sieve. The usual methods of preparation of AlPO4 are described elsewhere[1,3], i.e. gelification of a mixture of an aluminum salt (chloride, nitrate etc.) with orthophosphoric acid (or NaH2PO4) in the presence of a base. Ammonia, ethylene oxide, and propylene oxide are used as base mostly.

    Mechanism of Phenol Hydroxylation with Hydrogen Peroxide Catalyzed by Iron Complex Oxide
    LIU Qing-Sheng, YU Jian-Feng, WANG Zhen-Lü, JIANG Yu-Zi, WU Tong-Hao
    2000, 21(S1):  358-358. 
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    Dihydroxybenzene are both very important chemical products. The oxidation of phenol to produce catechol and hydroquinone has been researched extensively since the 1970s. In this paper, the iron complex oxide was prepared by the air oxidation of aqueous suspension method and the catalytic activities were investigated in the hydroxylation of phenol with H2O2 to catechol and hydroquinone. The results showed that the catalyst had higher catalytic activities and the phenol conversion could reach 24% when the phenol/H2O2 (mole ratio) was 3 and the catechol/hydroquinone (mole ratio) 1.5 in products. Furthermore, the interaction of the catalyst with H2O2 had also been demonstrated by IR spectrometry. In the presence of H2O2 a band at 956 cm-1 appeared and disappeared when the H2O2 is replaced by H20 or the catalyst was heated over 373 K, at which temperature decomposition of iron peroxide was very likely. The band at 956 cm-1 was due to the formation of structure of iron peroxide species and the stretching vibration of surface 0-0 species. The results of IR studies suggested that the catalyst might be react with hydrogen peroxide to form iron peroxide, which decomposed to produce·OOH radical. In the presence of DMPO (5,5-dimethyl-1-pyrroline-N-oxide) the·OH radical was also successfully captured in the hydroxylation of phenol by H2O2 over iron complex oxide catalyst in the first time that has been confirmed by means of ESR spectrometry. The results of ESR suggested the process of hydroxylation of phenol with H2O2 was probably a radical process. A possible mechanism of the catalytic process was proposed.

    Formation of Ordered Arrays of Gold Nanoparticles from CTAB Reverse Micelles
    LIN Jun, ZHOU Wei-Lie, O'CONNOR Charles-J
    2000, 21(S1):  359-359. 
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    In this presentation, a reverse micelle technique was described to create colloid gold nanoparticles and their self-organization into superstructures. Gold nanoparticles were prepared by the reduction of HAuCl4 in CTAB/octane+1-butanol/H2O reverse micelle system using NaBH4 as reducing agent. Dodecanethiol (C12H25SH) was used to passivate the gold nanoparticles immediately after formation of the gold colloid. After re-dispersing in toluene under ultrasonication, a supernatant containing nearly monodispersed dodecanethiol-capped gold nanoparticles was obtained. Self-organization of the gold nanoparticles into ID, 2D and 3D superstructures was observed on the carbon-coated copper grid by TEM. A representative TEM mirograph of the 2D array is shown in Fig. 1. UV/Vis absorption spectra were also used to characterize the gold colloids with and without dodecanethiol capping.

    Study on the Catalyst for Catalytic Air Wet Oxidation on Highly Organic Wastewater
    LI Guang-Ming, ZHANG Ying, HU Xiao-Jun, GAN Li-Hua, TANG Wen-Wei, ZHAO Jian-Fu
    2000, 21(S1):  360-360. 
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    The industrial effluents are as varied as the industries themselves, in terms of nature of contaminants, their concentration treatment, and disposal methods required. For the highly organic wastewater, the technique of wet air oxidation (WAO) is more available. Currently more than 200 full scale WAO plants are in operation for the treatment of a wide variety of effluent streams. In the recent years, the use of homogeneous and heterogeneous catalysts has received a great attention. The homogeneous catalysts are in general more effective oxidation catalysts for increasing the rates of oxidation. But it is necessary to make precipitation step to recover/remove the toxic catalyst from the final effluent In view of this, heterogeneous catalyst systems are preferable. So we investigated on the way of preparation of copper oxide on a spinel support of Al2O3) and its effects on the catalytic wet air oxidation (CWAO) on highly organic wastewater.

    Sulfate/Bisulfate Adsorption at the Pt(111) Surface
    LI Nan-Hai, LIPKOWSKI Jacek
    2000, 21(S1):  361-361. 
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    The cyclic voltammograms of Pt(111) electrode in sulfuric acid solutions display an anomalous wave and a unique butterfly peak. Extensive studies have been made to investigate these unique features since the advent of the flame annealing technique in 1980[1]. Yet, the assignment of these features to sulfate[2] or bisulfate[3] adsorption is still full of controversy and no conclusive evidence has been reported in the literature.

    Electrochemical Studies of Nanoparticle Self-Assembled Monolayers
    CHEN Shao-Wei
    2000, 21(S1):  362-362. 
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    Electrochemical studies of the self-assembled monolayers of gold nanoparticles were reported. The particle surface assemblies were constructed by using surface-active particle molecules where multiple copies of peripheral thiol groups were introduced via exchange reactions with alkanedithiols[1,2]. Excessive dithiol and displaced thiol ligands were removed from the cluster exchange solution by liquid extraction using a hexane-methanol system. The resulting particle adlayers exhibited discrete electron-transfer features that were ascribed to the quantized capacitance charging to the particle double layers. The electrode double-layer capacitance, evaluated from impedance measurements, also showed a modulation with electrode potentials. Consistent electron-transfer rate constants were obtained from the Laviron evaluation as well as from the impedance measurements[1].In particular, in aqueous solutions, in the presence of certain hydrophobic electrolyte ions, the discrete charging was rectified depending on the electrode[2].

    Normal and Abnormal Enhancement of IR Absorption of CO Adsorbed on Electrodes of Nanostructured Materials
    SUN Shi-Gang, JIANG Yan-Xia, ZHENG Ming-Sen, CHEN Sheng-Pei
    2000, 21(S1):  363-363. 
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    A new phenomenon of enhanced IR absorption has been revealed recently and reported in the present paper. In referring to the surface enhanced IR absorption (SEIRS)[l], which is limited to systems of particular molecules (PNBA, etc.) adsorbed on island films of Au, Ag metals, the newly discovered phenomenon is of significant importance in fundamental studies as well as in applications of electrocatalysis and surface analysis, since nanostructured transition metals or alloys were involved in this phenomenon.

    MCM-41 Supported Nickel Catalysts for Carbon Dioxide Reforming of Methane
    TIAN Hong, WANG Xiao-Lai, ZHANG Xiao-Ming
    2000, 21(S1):  364-364. 
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    There has been an increasing interest in the conversion of methane and carbon dioxide into synthesis gas[1]. High performance Ni-based catalysts have attracted much attention[2-4]. In this study, MCM-41 supported nickel were used as catalysts for carbon dioxide reforming of methane. It is found that the obtained catalyst exhibited high activity for getting syngas with its ratio of unity.In contrast to the performance of other nickel-based catalysts; Ni/MCM-41 has higher conversion and yield at lower temperature. The effects of nickel loading, particle size, GHSV, and calcination temperature on catalytic activities were also investigated.

    In Situ STM Studies of Copper Deposition on Platinum Stepped Pt(s)-[n(111)x(111)] Surfaces
    XIAO Xiao-Yin, BERENZ Peter, BALTRUSCHAT Helmut, SUN Shi-Gang
    2000, 21(S1):  365-365. 
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    In this paper, copper deposition on platinum stepped single crystals (Pt(332), Pt(665)) and Pt(111) has been respectively investigated by CV and EC-STM. It is shown that the feature of Cu UPD is functional to the step density, indicative of the increase in amplitude of the quasi-reversible peaks at 0.4 V with increase of step density.

    Unexpected Chemisorption State of CO2 on the Si(100)-2×1 Surface Predicted by Theory
    LU Xin, LIN Ming-Chang, ZHANG Qian-Er
    2000, 21(S1):  366-366. 
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    Li the past decade, the reactivity of carbon containing confounds with single crystal silicon surfaces has received extensive attention from both experimental and theoretical sides owing to its compact relevance to the growth of silicon carbide and diamond films. While considerable interest has been focused on the adsorptions of alkenes, alkanes and some other small organic molecules[1], very few experiments[2,3] can be found in the literature regarding the adsorption of CO2,a greenhouse gas, on Si surfaces. We report herein the results of our recent theoretical study concerning CO2 adsorption on the reconstructed Si(100)-2×l surface. The methods employed in our calculations are the hybrid density functional B3LYP method and a two-layer ONIOM (CCSD(T):B3LYP) approach[4].

    PH-Dependent Water Structure at a Quartz Surface Modified with an Amino-terminated Monolayer Studied by Sum Frequency Generation
    YE Shen, NIHONYANAGI Satoshi, UOSAKI Kohei
    2000, 21(S1):  367-367. 
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    Sum frequency generation (SFG) is a second-order nonlinear optical process in which two photons at frequencies W1 and w2 generate a photon of sum-frequency at w3=w1+w2. SFG does not occur in media with inversion symmetry and is only active on the surface or interface where the inversion symmetry is necessarily broken[1]. In the IR-visible SFG measurement, a visible laser beam (w1) and a tunable infrared laser beam (w2 are overlapped at an interface and the SFG signal is measured by scanning w2 while keeping w2 constant. The SFG is enhanced when w2 is equal to the vibration levels of molecules at the interface[1].

    First Principle Based Computation:Applications to Applied Chemistry and Engineering
    WANG Yi-Ning, XU Yuan-Yuan, XIANG Hong-Wei, LI Yong-Wang
    2000, 21(S1):  368-368. 
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    Computer simulation on the basis of the first principle approaches has increasingly emerged in both fundamental chemistry and engineering fields. In the development of widely used catalytic processes, the science and engineering aspects in chemical related subjects are the good examples in projecting the demands for the continuously growing computational technologies. The presentation will take two examples from our recent effort in both quantum mechanics applications to the analysis of MoS2 catalyst (HDS) and the CFD calculation of the flow field in a packed bed catalytic reactor to explore the phenomena induced by flow. The main points of our topic are on the crucial demands for both theoretical and technical improvements in the applications of first principle methods to chemistry and chemical engineering.

    The Structure and Properties of Mesoporous TiO2 Film Photocatalyst
    ZHU Yong-Fa, ZHANG Li, CAO Li-Li
    2000, 21(S1):  369-369. 
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    As a good photocatalyst, TiO2 has a promising prospect in environmental purification[1]. Due to the technical problem for the separation of dispersed TiO2 nanosized catalyst, TiO2 film photocatalyst has become a better choice for TiO2 photocatalyst used in fluid[2]. Because TiO2 thin film photocatalyst has small surface area, the catalytical activity was very low. It was an effective way to use mesoporous TiO2 film with high surface area as photocatalyst. The structure and properties of mesoporous TiO2 film was studied here.

    Dehydration of Isopropanol to Diisopropyl Ether over Nb2O5/Hβ
    WANG Hai-Yan, MA Jun, CHEN Wen-Yi
    2000, 21(S1):  370-370. 
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    Niobic acid is a unique catalyst with moderate acid strength and water- resistance property. As a result of its properties, niobium oxide exhibit unique activity, selectivity and stability for many different catalytic reactions,for example, olefin hydration, alcohol dehydration, and alcohol esterification[1,2]. In this paper, Nb2O5 was used as the starting material, and HP used as the support. First, Nb2O5 was mixed with Hβ in a given ratio, then grinded followed by microwave irradiation or calcination at 773K. Several preparation variables and reaction conditions were studied. Dehydration of isopropanol was carried out in a fixed-bed reactor. The reaction products were analysed by GC.

    Study on Preparation and Catalytic Performance of Silica Supported Cesium Acid Salts of 12-tungstophoric Add
    WANG Hai-Yan, ZHOU Ding, MA Jun, CHEN Wen-Yi
    2000, 21(S1):  371-371. 
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    Supported Cesium Acid Salts of 12-tungstophric acid exhibit very high activities as catalysts for various reactions, because of their superacidity, high surface area and insolubility in water and polar solvents[1,2]. In this work, supported Cesium acid salts are prepared by first impregnating the aqueous solution of Cesium Carbonate onto SiO2, followed by drying and calcining, then impregnating the aqueous solution of H3PW12O40, followed by drying and calcining. The etherification of Light FCC Gasoline with methanol was conducted in a Fixed-bed reactor. Products were analyzed by GC.

    Study on Sulphided WNi/USY+Al2O3 Catalyst by XPS
    ZHANG Xi-Wen, SUN Wan-Fu, LING Feng-Xiang
    2000, 21(S1):  372-372. 
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    Ni-promoted tungsten catalysts are widely used for hydrotreating various petroleum fractions. The catalysts have to be sulphided prior to use in industry, because sulphided catalyst has higher activity and more stability. The influence of the sulphiding conditions on the performance of WNi/Al2O3 has been investigated by some reseachers[1] except for WNi/USY+Al2O3 hydrocracking catalyst. In this paper, the optimal sulphiding conditions of WNi/USY+Al2O3 have been studied by XPS.

    Electrocatalytic Oxidation of HCOOH on Pt(331)/Sb Electrode
    YANG Yi-Yun, ZHOU Zhi-You, GU Yan-Juan, CHEN Sheng-Pei, SUN Shi-Gang
    2000, 21(S1):  373-373. 
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    Single crystal planes provide surface models of well defined atomic arrangement. Using the method of UPD and irreversibly adsorption (IRA) to modify electrode with adatoms can change the composition,the symmetry of atomic arrangement and the electronic structure of electrode surface[1]. We have studied in this paper the electrochemical behavior of irreversibly adsorbed antimony on Pt(331) (Pt(331)/Sb) and HCOOH oxidation on R(331)/Sb. The result demonstrated that the IRD Sb adatoms on Pt (331) was stable at potentials below 0.30 V (SCE). We illustrated that various coverage of Sbad can be easily obtained by controlling the number of potential cycling and the upper limit of potential scan (Eu). The coadsorption of Sb with H on Pt(331) surface was characterized by relation between the coverage of Sb (θSb) and that of Had (θH). Two domains were determined:(1) when θSb is small than 0.10, dramatic decrease of θH with θSb is manifested, meaning that hydrogen adsorption can be inhibited significantly by a small quantity of Sbad; (2) when θSb is large than 0.10, θH maintains almost a constant value near 0.025.

    Surface Structure and Electrocatalytic Activity of Ru(0001) and Ru/Pt(111) Single Crystal Electrodes:In-situ FTIR and ex-situ LEED, RHEED and AES Studies
    LIN Wen-Feng
    2000, 21(S1):  374-374. 
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    In-situ FTIR spectroscopic and electrochemical data, and ex-situ (emersion) electron diffraction (LEED and RHEED) and Auger electron spectroscopic (AES) data are presented on the structure and reactivity, with respect to the electro-oxidation of CO, of the Ru(0001) single crystal surfaces in perchloric acid solution. In both the absence and presence of adsorbed CO, the Ru(0001) electrode shows the potential-dependent formation of well-defined and ordered oxygen-containing adlayers. At low potentials (eg. from -80 to +200 mV vs Ag/AgCl), a (2 x 2)-O phase is formed, which is unreactive toward CO oxidation, in agreement with UHV studies; increasing the potential results in the formation of (3 x 1) and (1 x 1) phases at 410 mV and 1100 mV, respectively, with a concomitant increase in the reactivity of the surface toward CO oxidation. Both linear (COL) and threefold-hollow (COH) binding CO adsorbates (bands at 2000-2040 cm-1 and 1770-1800 cm-1, respectively) were observed on the Ru(0001) electrode. The in-situ FTIR data show that the adsorbed CO species still remain in compact islands as CO oxidation proceeds, suggesting that the oxidation occurs at the boundaries between the COad and active Oad domains via the Langmuir-Hinshelwood mechanism. At low CO coverages,reversible relaxation, (at lower potentials), and compression, (at higher potentials), of the COL adlayer were observed and rationalised in terms of the reduction and formation of surface O-adlayers, The data obtained from the Ru(0001) electrode are in marked contrast to those observed at polycrystalline Ru, where only linear CO is observed.

    ATR-FTIR Study of Si(110) Surface Hydrogenated in NH4F-Based Mixtures
    WANG Yi, LI Jing, YE J.H., LI S.F.Y.
    2000, 21(S1):  375-375. 
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    RCA (Radio Corporation of America) cleaning has been the important and critical step in semiconductor manufacturing for more than 30 years[1]. As the electronics devices are shrinking and gate oxide is getting thinner, stringent requirements on metallic impurities,organic contamination and surface roughness on silicon wafer after wet chemical cleaning have attracted more attention in the mechanism of wet etching processes on Si(111) and Si(100) surfaces[2=11]. In the past few years wet chemical and electrochemical etching of Si(110) in NH4F solutions has been studied by using scanning tunneling microscopy (STM)[12] and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR)[13-14]. In the present work, we extend our study to Si(110) surface in NH4F/HCl mixtures by using polarized attenuated total reflection FTIR (ATR-FTIR). We have compared the ex-situ ATR-FTIR results on Si(110) in various NH4F/HCl solutions using Ge prism. Effects of potential on hydrogen-terminated structures on Si(110) surfaces have been investigated by employing in-situ electrochemical ATR-FTIR with double side polished single crystal silicon as a prism. Our ATR-FTIR spectra are correlated with the results obtained with in-situ STM.

    ATR-FTIR Investigation of Hydrogen-terminated Si(111) Surface in Various NH4F-Based Solutions
    LI Jing, WANG Yi, YE J.H., LI S.F.Y.
    2000, 21(S1):  376-376. 
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    Wet chemical cleaning of silicon is a critical step in the semiconductor manufacturing. Particles, contaminants, metallic impurities, roughness and native oxide on silicon surface after wet chemical cleaning deteriorate the reliability of transistor performance in integrated circuits[1]. Wet chemical etching of Si(111) and Si(100) in fluoride and alkaline solutions has been extensively studied in the past few years by using scanning tunneling microscopy (STM) and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR)[2-11]. In the present work, we extend our study to Si(111) surface after treating with NH4F/HCl mixtures. STM, X-ray photo spectroscopy (XPS), and ATR-FTIR are used to determine surface roughness, contamination and bond information on Si(111) surface after wet chemical cleaning with various NH4F/HCl mixtures. The results are discussed in details by comparison to those treated with RCA and HF solutions, indicating that ultra-clean and flat Si(111) surface is obtained by treatment with NH4F/HCl mixture.

    Scanning Tunnelling Microscopy Study of Chloride Adsorbed on Cu(110) Surfaces in Hydrochloric Acid Solution
    LI W.H., WANG Yi, YE J.H., LI S.F.Y.
    2000, 21(S1):  377-377. 
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    Fundamental studies of the interaction of chloride with copper is of great interest from both scientific and technological view points since it is related to the copper electroplating and also the halogen etching processes[1]. In this paper, in-situ scanning tunneling microscopy (STM) has been employed to study chloride adsorption on Cu(110) electrode in hydrochloride acid aqueous solution. The atomic resolution images of chloride adsorbed on Cu(111) surface have been obtained over the potential range from -400 mV to -100 mV (vs. SCE). A (l×l) structure for Cu(110) substrate was observed at the potential negative than -450 mV in which the chloride anions are desorbed. Our results indicate that the chloride anions are very strongly adsorbed on the Cu(110) surface at the potential positive than -400 mV. The images taken over a large region show parallel rows on the terraces and monolayer straight steps, which run along the[001] direction of the substrate lattice. The parallel row structures observed here are suggested to attribute from the chloride adlayers. The different corrugation height and periodical modulation in the height along[110] direction observed indicates that chloride anions are located at physically non-equivalent binding sites. Models are proposed to interpret the structures with three-fold periodicity and four-fold periodicity along[110] direction with a (4×1) structure containing three chloride anions and a (5×1) structure containing four chloride anions, respectively.

    Ultra-clean Si(111) and Si(001) Surfaces Prepared by Advanced Wet Chemical Cleaning
    YE J.H., LI Jing, BOK T.H., PAN J.S., LIS.F.Y.
    2000, 21(S1):  378-378. 
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    Wet chemical cleaning of silicon is a critical step, e.g., pre-gate clean, in the semiconductor manufacturing[1]. For example, pre-gate oxide cleaning demands ultra-clean silicon surface with least surface roughness. It is well known that metallic infinities and roughness cause the lower breakdown voltage in gate dielectric[2]. It has stringent requirements for ultra-clean and atomically flat silicon surface as the thickness of gate oxide is decreasing. In the present work, we have extended our study on Si(100) surface13] and extensively investigated wet chemical cleaning of Si(111) and Si(100) surfaces in NH4F-based solutions by using scanning tunneling microscopy (STM), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and total reflection X-ray fluorescence spectrometry (TXRF). Surface roughness, organic contamination, metallic impurities and surface termination on the silicon surfaces after wet chemical cleaning with various NH4F-based solutions have been determined and compared with those treated with RCA cleans, HF solutions and other industrially used solutions. Our results indicate that ultra-clean and smooth Si(111) and Si(001) surfaces are obtained by treatment with NH4F-based solutions.

    A Density Functional Study of Small Tungsten Clusters Adsorbed on the MgO(001) Surface
    CAI Shu-Hui, NEYMAN Konstantin M., ROSCH Notker
    2000, 21(S1):  379-379. 
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    Metal atoms, clusters, and thin films supported on surfaces of metal oxides have attracted a lot of attention not only due to the fundamental interest in the basic nature of metal-oxide interfaces, but also because of their numerous practical applications in catalysis, microelectronics, as coatings for corrosion protection and gas-sensors[1,2]. In this paper, adsorption of tungsten clusters Wn (n=l-4) on the ideal MgO(001) surface has been studied computationally at the density functional (DF) level of theory with the help of a scalar-relativistic variant of the linear combination of Gaussian-type. orbitals density functional method (LCGTO-DF)[3] as implemented in the program PARAGAUSS for parallel computing[4]. Stucture and energetic features of the adsorption complexes Wn/MgO(001) have been analyzed. The gradient-corrected Becke-Perdew functional was used self-consistently. Spin-polarized calculations were performed in order to account for the possible open-shell nature of the metal clusters.

    Electrochemically Assisted Photocatalytic Degradation of Methylene Blue Aqueous Solution with Three Dimensional Electrodes
    AN Tai-Cheng, ZHU Xi-Hai, XIONG Ya
    2000, 21(S1):  380-380. 
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    Heterogeneous photocatalytic processes using semiconductor catalysts is a good advanced oxidation technology for organic pollutants. Titanium dioxide under the shape of anatase is the most commonly used as the best photocatalyst because anatase form has reasonable photo-activity with the advantages of no-toxic, insoluble and comparatively inexpensive[1].

    Ni/TiO2 Catalyst for Partial Oxidation of Methane to Syngas
    LUO Chun-Rong, YAN Qian-Gu, WENG Wei-Zheng, WU Ting-Hua, WAN Hui-Lin
    2000, 21(S1):  381-381. 
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    Ni/TiO2 catalyst was firstly used for the partial oxidation of methane to produce synthesis gas. The reaction was carried out in a fixed-bed continuous flow quartz reactor at atmospheric pressure. The flow rate was regulated by a mass controller with a space velocity of 1.5×105 h-1 and a CH4/O2 molar ratio of 2/1. Prior to the introduction of feed gas, the Ni/TiO2 catalyst was activated in flowing H2 at 700℃ for 30 min. TiO2 is known to be a poor support for partial oxidation because which can easily result in complete oxidation. But at 700℃, Ni/TiO2 catalyst exhibited a better performance than Ni/SiO2 and Ni/ZrO2. The conversion of methane was 81.5, and the selectivity of hydrogen and carbon monoxide were 93.4 and 89.4 respectively. After 6h of continuous reaction, the conversion of methane descended a little and then remained a steady yield on the whole,but the selectivity of H2 and CO gradually declined, as far as to a constant. The selectivity of H2 was always higher than that of CO and the ratio of H2/CO wouldn't change with the increasing of reaction time.

    Degradation of Phenol in Water by Photocatalytic Reactors
    CHEN Hui, GUO Hong-Yu, LIU Xiu-Feng
    2000, 21(S1):  382-382. 
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    Environmental applications of heterogeneous photocatalysis are one of the rapidly growing areas of research. Photocatalytic oxidation had die advantage of complete mineralisation of pollutants into environmentally harmless confounds. In recent years, interest has focused on the use of TiO2 as a photocatalyst for the destruction of polluting materials[1,2].

    Effect of SO2 on the NO Oxidation over NiO/γAl2O3 Catalyst
    LI Ping, ZHAO Yue, LU Guan-Zhong, ZHAO Xiu-Ge, LU Wen-Zhi, XIAO Wen-De
    2000, 21(S1):  383-383. 
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    NO is the dominant component of NOx. It can be easily oxidized to NO2 over active catalysts in the oxidizing exhaust gases. And then, the high reactive NO2 can be removed completely further through adsorption or absorption approach. However, SO2,another main contaminant in the exhaust, is well known to poison the oxidative catalysts. A strong deactivation for metal oxides supported on Al2O3 was found when catalysts had been exposed to the gas containing 500ppm SO2. It was also reported that the inhibition effect of SO2 was enhanced at low temperatures. But recently, some studies declare that the oxidation of propane can be promoted over Pt/γ-Al2O3 if a small amount of SO2 (20 ppm) is present in the feed gas[1]. Jang et al. have also found that SO2 has a promoting effect for the oxidation of NO to NO2 over CO3O4/γ-Al2O3 catalyst[2]. These observations are meaningful because the existence of SO2 in the oxidizing exhaust is often inevitable and the problem of catalyst deactivation by SO2 has puzzled researchers for a long time.

    Templating Effect of Amion Monolayers on the Formation of Anionic Clay Sheets at an Air-Water Interface
    HE Jun-Xiang, YAMAGISHI A., JONES W.
    2000, 21(S1):  384-384. 
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    Monolayers have been reported to play a template role in the formation of minerals at interfaces. For example, the oriemted nucleation of calcite is controlled by self-assembled monolayers (SAMs) of to-terminated alkanethiols ((CH2)nX)[1].This presentation shows the templating effect of a Langnuir monolayer of stearic acid (SA) during the preparation a thin film of anionic clay, The work is an extension of our previous works on the formation of a hybrid film of a clay and a metal complex by the Langmuir-Blodgett (LB) method[2].

    AFM Tip-Directed ID and 0D Assembling of Colloidal Au Nanoparticles on Silicon
    LI Qi-Guang, ZHENG Ji-Wen, LIU Zhong-Fan
    2000, 21(S1):  385-385. 
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    Colloidal Nanoparticles have received renewed interests recently from the viewpoint of nanoscale science and technology. Using chemical assembling techniques, one can fabricate well-organized 2D nanoparticle arrays on solid substrates and use it as the Coulomb island for room temperature single electron tunneling[1], as nanoelectrode for electrochemistry studies[2], as active substrate for surface enhanced Raman scattering (SERS)[3,4],as lithographic mask for fabrication of nanostructures[5] and etc.

    In situ Study of Scanning Tunneling Microscopy On Passivation and Pit Corrosion of Stainless Steel
    HU Yan-Ling, HU Rong-Gang, SHAO Ming-Hua, LIN Chang-Jian
    2000, 21(S1):  386-386. 
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    Traditional ways to investigate passivation and pitting is indirect electrochemical method.In this article, direct information for topography of ultrathin passivating film is obtained by employing in-situ ECSTM to stainless steel (Cr11Ni13 SS). Passivating potentials including 0V,0.2V, 0.5V and 0.8V (Vs.SCE) are applied to the sample in 0.5M H2SO4+0.02M NaCl respectively, while surface topography is recorded by STM on the same region, with dimension of 800×800 nanometers. ECSTM result provides a microscopic explanation of EIS. The result describes as fig. 1 and fig. 2.

    Multinuclear Solid State NMR for the Study of Chemistry in Surface Science
    TAO Ting, MACIEL Gary E.
    2000, 21(S1):  387-387. 
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    This presentation will cover recent progress in the development and application of solid-state NMR techniques for characterizing surface chemistry. Several technological important systems, such as "ship-in-a-bottle" synthesis in zeolite, chemical immobilization on polymer surface and environmental pollutant-soil interactions, have been investigated by multinuclear solid- state NMR spectroscopy. An in situ sold-state NMR technique, GRASSHopper, has been introduced to study heterogeneous catalysis under flowing conditions.

    Directing Copper Deposition on Ethylene Modified Pt(111) Surface Inducing Nanostructure
    XIAO Xiao-Yin, BERENZ Peter, BALTRUSCHAT Helmut, SUN Shi-Gang
    2000, 21(S1):  388-388. 
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    More than 80% of ethylene has been found to be difficult displaced by Cu-UPD or even Cu-OPD on Pt(111)[1]. The STM images of ethylene adsorbed on Pt(111) at 0.1 V vs Cu/Cu2+ show that the overall structure of adsorbate is disordered, wherever, the single adsorbate is still visible. This structure does not change too much after the displacement by Cu-UPD.

    Electrodeposition Under High Magnetic Field
    YU Qing-Kai, SEIICHIRO Nakabayashi
    2000, 21(S1):  389-389. 
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    The film growth under high magnetic field using a super-conducting magnet is discussed from the view point of a magnetization energy. The film configuration in nickel eletrodeposits with and without the high magnetic field was examined by means of the AFM (Atomic Force Microscopy), In the absence of magnetic field, the film surface appeared irregular structure. However, when the magnetic field was imposed in parallel to the cathode plate, nickel deposited shown clearly ordered stationary structure. The experimental results could be explained by nickel magnetic anisotropy. On the other hand, when the field was imposed in perpendicular to a cathode plate, deposition structure is controlled by the fluid motion induced by Lorentz force.

    Study on the Corrosion Resistance of 304L Stainless Steel
    DU Rong-Gui, HUANG Ruo-Shuang, HU Rong-Gang, FENG Zu-De, MU Ji-Qian, HU Yan-Ying, TAN Jian-Gang, LIN Chang-Jian
    2000, 21(S1):  390-390. 
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    304L is an austenitic stainless steel with very low carbon content, and is served as the application to the oxidizing media, however, its corrosion resistance is not satisfactory in reducing media. For example, the pitting corrosion occurred on 304L stainless steel tube, which had been mounted for one year, somewhere at the power station in die seashore of China. For this reason we have studied the corrosion behavior of 304L in some media and invented a novel surface treatment technique of stainless steel for extremely improving the corrosion resistance of 304L. The characteristics of the modified passive film on the steel were examined in this paper, and the corrosion resistance of treated 304L stainless steel was tested in our laboratory and the testing ground. The results are satisfactory.

    Effects of Surface Structure of Pt(100) Electrode on Kinetics and Reaction Mechanism of CO2 Reduction
    ZHOU Zhi-You, YANG Yi-Yun, CHEN Sheng-Pei, ZHEN Chun-Hua, SUN Shi-Gang
    2000, 21(S1):  391-391. 
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    CO2 is a potential and abundant carbon resource. Electrochemical reduction of CO2 can transform it to hydrocarbons and alcohols at room temperate and under atmospheric pressure[1]. Among metal electrodes studied, Pf is the unique one that reduces CO2 at low overpotential. However the reduction mechanism, especially the surface processes, of CO2 reduction is not clear yet. Well-defined single crystal electrodes can provide the possibility to investigate surface processes of CO2 reduction at a level of atomic arrangement.

    Effects of Preparation Methods and Interaction between Support and Oxide for Oxidative Dehydrogenation of Ethane over NiO/ZrO2
    CHEN Tong, GUO Feng-Yuan, JIN Ming-Gong, WAN Hui-Lin
    2000, 21(S1):  392-392. 
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    The previous studies indicated that the unsupported and alumina supported nickel oxide catalysts are the attractive candidates for the oxidative dehydrogenation of ethane (ODE) reaction at lower reaction temperature[1,2]. In the present study, NiO/ZrO2 catalysts were prepared by the impregnation, complex of ammonia and coprecipitation, respectively, using the conventional incipient wetness technique. Over all samples used in this study, no NiO crystal structure was detected by XRD measurements carried out in parallel with the present work, which indicated the nickel oxide was highly dispersed on the support The blank testing indicated that the support ZrO2 had very little activity below 600℃. Comparing with the unsupported nickel oxide, it was found that the activity of NiO/ZrO2 catalysts prepared by the methods mentioned above decreased slightly and the selectivity for ethylene improved. With the increasing temperature, the ethane conversion increased and the selectivity for ethylene decreased However, the cracking of the ethane occurred at ca.450℃ on all samples prepared by different methods. The optimum catalytic behavior could be obtained on 5wt%NiO/ZrO2 prepared by coprecipitation, with the ethane conversion of 26.2% and selectivity for ethylene of 51.8% at as low temperature as 350℃. The sample prepared by coprecipitation and calcined at 500℃ was calcined again at 600℃ for 5 h,the activity decreased obviously, which may be attributed to the existence of the interaction between nickel oxide and support taking into account for the high dispersion of NiO on ZiO2.

    Separation Cd(Ⅱ), Fe(Ⅲ) and Zn(Ⅱ) from Eu(Ⅲ) in Sulfuric Acid with Cyanex302 by Using Microporous Hollow Fiber Membrane
    LUO Fang, LI De-Qian, WU Yong-Lie
    2000, 21(S1):  393-393. 
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    With the development of chemical industry, refining and collecting valued material in dilute solutions or difficult separation systems has become one of important research aspects. In order to adapt to the demand of modem science and technology, separation Zn2+, Cd2+ and Fe3+ from Eu3+ solution to making Eu with high purity is necessary. Hollow fiber membrane (HFM) extraction, as a new separation technique, has many advantages[1]. The extractant(commercial name as Cyanex302), bis(2,4,4-trimethylpentyl)monothiophosphinic acid, is a soft acid and so it is easy to extract transition elements[2]. HFM extraction combined with a new extraction system, which had little consumption and no pollution and was a friend environment process.

    Ruthenium Catalyst Supported on New Type of Graphite-Doped Alumina for Ammonia Synthesis
    LI Xiao-Nian, JI De-Chun, ZHU Yi-Feng, LIU Hua-Zhang
    2000, 21(S1):  394-394. 
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    In the study of Ru catalyst, various supports have been used, e. g. MgO, Al2O3, MgAl2O4, zeolite active carbon[1-3]. The carbon covered alumina offers the advantages of the electron withdrawing capacity of carbon and the stability of alumina and at the same tame eliminates the disadvantages of the low strength of carbon and the acidity of alumina. In the present work., we describe the synthesis and reactivity of ruthenium supported on various Al2O3 for the production of ammonia from hydrogen and nitrogen.

    CeO2 Enhance Conversion Intermediates to Target Product During Selective Oxidation of Propane to Acrolein
    ZHANG Xin, WENG Wei-Zheng, YUAN Ru-Ming, WAN Hui-Lin
    2000, 21(S1):  395-395. 
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    Poor degree of conversion intermediates to acrolein is one of reasons on low selectivity in acrolein obtained during the selective oxidation of propane[1]. In this paper, the stimulative role of promoter CeO2 on directional conversion intermediates to acrolein was investigated, over Ce-Ag-Mo-P-0 catalyst for selective oxidation of propane.

    Extending Surface Raman Spectroscopic Study to Rh
    REN Bin, LIN Xu-Feng, TIAN Zhong-Qun
    2000, 21(S1):  396-396. 
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    Raman Spectroscopy is a powerful technique in characterizing the surface structure at the molecular level. Rh, due to its special application as catalysts in the catalytic and electrochemical reaction, has been one of the most important materials in surface sciences. However, Rh surface has not been considered as an appropriate substrate for generating prominent SERS effect. Furthermore, it was found very difficult to be roughened since it will grow naturally in air an oxide layer to retard the further formation of the surface oxide and it is very easy to form various forms of rhodium oxides as indicated in the phase diagram of Rh[1]. To select a method to roughen the surface and to extend SERS to Rh seem not an easy task.

    Novel VPO Catalysts for n-Butane Oxidation to Maleic Anhydride:The Effects of Combined Moderators, Preparation Procedure and MCM-41 Supports
    NIE Wei-Yan, WANG Xiao-Shu, JI Wei-Jie, YAN Qi-Jie, CHEN Yi
    2000, 21(S1):  397-397. 
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    VPO catalysts are widely used in selective oxidation of n-butane into maleic anhydride (MA)[1-2]. In the recent years, there is an obvious trend worldwide that the selectivity of a target product is more emphasized than the overall conversion, to decrease the undesired by-products. In this study, different approaches have been tried to generate more environmentally friendly VPO catalysts, with high MA selectivity and improved n-butane conversion. The moderated catalyst was prepared in aqueous phase[3]. For comparison, the moderators were also introduced by impregnating the VPO precursor synthesized in organic medium. The supported VPO systems on the MCM-41 mesopore materials were prepared by employing the reaction of V2O5 with isobutanol in the presence of MCM-41 fine powder with different Si/Al ratios. The catalysts were evaluated at 385-425℃ and characterized by XRD, XPS and TPR etc.

    A Comparative Study on the Influence of Submonolayer Coverage Sn on SERS of Au and Pt Substrates
    YAN Jia-Wei, SHE Chun-Xing, TANG Jing, TIAN Zhong-Qun, MAO Bing-Wei
    2000, 21(S1):  398-398. 
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    Since the discovery of the surface enhanced Raman scattering (SERS) in mid-1970's,great efforts have been devoted to understand the enhancement mechanism as well as to extend the SERS system and application. There has been a consensus that the electromagnetic enhancement (EM) and chemical enhancement are the two important SERS mechanisms but each of them can only explain some of experimental results[1,2] The EM mechanism relies on the surface plasmon resonance under a proper incident laser excitation. Strong EM enhancement has been observed on metals such as Cu, Ag and Au but not on transition metals such as Pt. However, the surface electronic properties can be modulated through submonolayer quantity modification of foreign metal atoms, hi this paper, we report a comparative study on SERS of Au and Pt in the presence of underpotentially deposited (UPD) submonolayer Sn.

    SERS, AFM and Electrochemical Characterization of Metal Nanorod and Nanowire Arrays
    TANG Jing, LIN Rong-Gang, JIANG Yu-Xiong, YAO Jian-Lin, MAO Bing-Wei, SUN Dong-Mei, XUE Kuan-Hong, REN Bin, TIAN Zhong-Qun
    2000, 21(S1):  399-399. 
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    Metal nanowires (nanorods) have novel properties and potential applications in a wide field[1]. Many two-dimensional nanowire arrays of semiconductors and metals with different diameter and length have been made using template synthesis method[2]. The nanorod arrays of various metals (e.g., Cu, Ag,Au, Ni and Co) with different diameters from about 15 nm to 130 nm were fabricated by electrodeposition of the metals into the highly ordered nanochannel arrays in alumina film followed by partial removal of the film in phosphoric acid or sodium hydroxide. In the present work, surface-enhanced Raman spectroscopy (SERS), AFM and electrochemical methods have been used to characterize the metal nanorod (nanowire) arrays. Tapping mode AFM and SERS were performed on Nanoscope Ⅲa (Digital Instruments) and on confocal Raman microscopy (LabRam I,Dilor) respectively.

    A New Mechanism for the Formation of the Ozone Hole in the Earth Atmosphere
    LU Qing-Bin, SANCHE Leon
    2000, 21(S1):  400-400. 
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    It is generally accepted that the Earth ozone layer is depleted by chlorine atoms produced via solar photolysis of chlorofluorocarbons (CFCs) in the upper stratosphere[1]. This photodissociation model predicts an ozone depletion maximum at an altitude between 30 and 40 km and negligible ozone depletion below 20 km[1]. However, the Antarctic/Arctic ozone hole appearing in each spring is observed to be located at an altitude of about 15 km[2]. The formation of the ozone hole has been attributed to heterogeneous reactions on the surface of polar stratosphere clouds (PSCs) consisting mainly of condensed water ice:HCl+ClONO2→Cl2+HNO3[3,4]. Recently, it has been observed that dissociation of CFCs by capture of low-energy electrons is enhanced by several orders of magnitude when CFCs are adsorbed on the surfaces of ice films of polar molecules such as H2O and NH3[5,6]. This enhancement is due to transfer of electrons in precursors of solvated states in polar molecular ice to CFCs that then dissociate[7]. This effect should be most efficient in the lower stratosphere of about 15 km, where low-energy electrons can be produced by cosmic-ray ionization and localized in precursors of solvated electrons in PSCs[8]. Strong and straightforward evidence of this new mechanism for ozone depletion has also been found in data obtained from field measurements (satellites, balloons, etc.)[8]. In this talk, we will present the data from both field and laboratory measurements and discuss the new mechanism for the formation of the ozone hole.

    Modeling of Reaction Mechanism for the Selective Oxidation of Propylene to Acetone over V2O5/TiO2 Catalysts
    LI Ming-Shi, SHEN Jian-Yi
    2000, 21(S1):  401-401. 
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    Titania supported vanadia catalyst exhibits the high activity for the selective oxidation of propylene to acetone. The rate for the formation of acetone at 463 K was determined to be 98 μmol g-1 min-1, corresponding to the TOF of 2×l0-3 s-1. Kinetic results show that the reaction exhibits the first order to propylene, zeroth order to oxygen and 0.5th order to water at 383-433 K. XRD, UV-visible spectra and oxygen chemisorption reveal that the highly dispersed polyvanadates are the main vanadium species on titania. FT-IR and microcalorimetric studies for NH3 adsorption indicate that the polyvanadates on the surface of V2O5/TiO2 catalyst produced the Brönsted acid sites with the initial heat of 104 kJ/mol. The initial heats for adsorption of propylene, water, isopropanol, acetone and oxygen on V2O5/TiO2 catalyst are 104,88,53,106,and 416 kJ/mol,respectively.

    The Cross Link of Surface Enhanced Raman Scattering with Surface Science and Nanoscale Science
    TIAN Zhong-Qun, YAO Jian-Lin, WU De-Yin, TANG Jing, SUN Dong-Mei, XUE Kuan-Hong, REN Bin, MAO Bing-Wei
    2000, 21(S1):  402-402. 
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    The discovery of surface enhanced Raman scattering (SERS) in the mid-1970s impacted on the surface science community because of its remarkably high and unique surface sensitivity. Surface roughness in scale of 10~100 nm have been found necessary to produce the giant SERS signal. In this paper we will show that SERS is indeed one of the important phenomena not only in surface science but also in nanoscale science[1].

    Reconstruction-Dependant Self-Assembly of n-Alkanes on Au(111)
    XIE Zhao-Xiong, XU Xin, TANG Jing, MAO Bing-Wei
    2000, 21(S1):  403-403. 
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    Highly ordered molecular monolayers at the solid/liquid interfaces play a critical role in many technologically important areas, such as lubrication, adhesion, molecular recognition and chemical reactions. Although there are a number of results on the monolayers of organic molecules physisorbed on the solid surfaces being reported, the role of the substrate lattice parameters, the substrate structures and the defects in the formation of the highly ordered monolayers has not yet well explored. In this paper, we reported the scanning tunneling microscopy (STM) studies of the self-assembling phenomenon of n-alkanes in the interfaces between n-alkane solutions and the Au(111) surfaces.

    Chemistry in Materials Sciences
    Electrodeposition Carbon Nitride Films from Organic Solutions
    CAO Chuan-Bao, FU Qiang, FU Ji-Yu, ZHU He-Sun
    2000, 21(S1):  404-404. 
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    Since the theoretical predictions of the hypothetical β-C3N4 compound may have extraordinary physical and chemical properties[1], A variety of deposition techniques have been developed to investigate the synthesis of the novel material. The synthesis of carbon nitride has become an area of intense interest in materials science and great progress has been made[2]. However, the methods used to this task are all vapor deposition techniques or solid state preparation methods. Synthesis of crystalline β-C3N4 with chemical stoichiometry content of nitrogen is very difficult. The use of appropriately designed molecular and low enough synthesis temperatures to insure kinetic control of reaction products appears to be a promising direction.

    Chemistry in Surface Science
    CO Oxidation Activity and Characterization of Ag-Mn、Ag-Ce and Ag-Cu Mixed Oxide Catalysts
    LIN Rui, LIU Wei-Ping, ZHONG Yi-Jun, LUO Meng-Fei
    2000, 21(S1):  405-405. 
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    Catalytic oxidation is an efficient way to convert CO to CO2 at low temperature. Precious metal catalysts such as Ft and Pd have been demonstrated to be very effective[1]. However, attention has also been given to base metals due to the limited availability of precious metals. As a single component base metal catalyst cannot rival a precious metal catalyst, improvement in its activity has been attempted by combining several elements[2,3]. In the present work, we studied redox and structure of Ag-M(M=Mn、Ce and Cu) catalysts to gain some evidence of the synergism between Ag and base metals, and investigated their catalytic activities.

    Determination of Acidity of Hydrocracking Catalyst Support
    MA Bo, SUN Wan-Fu, ZHANG Xi-Wen, LING Feng-Xiang, CHEN Li-Ren
    2000, 21(S1):  406-406. 
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    In hydrocracking, the most hinges are to develop a good quality catalyst, and the key is to prepare a high quality support. Generally speaking, the support of hydrocracking catalyst consists of Al2O3,SiO2-Al2O3, zeolite and so on. The composition of the support can be changed or modified according to the acid property required by the reaction. Therefore, to study the acid amount and distribution of acid strength of each single component will give us insight into the development of to design a good support.

    Effect of SO2 on the NO Oxidation over Different Oxide Supports
    ZHAO Yue, LI Ping, LU Guan-Zhong, LU Wen-Zhi, ZHAO Xiu-Ge, XIAO Wen-De
    2000, 21(S1):  407-407. 
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    The catalytic oxidation of NO to NO2 in flue gas will enable removal of NOx through wet scrubbing of NOx simultaneously with SO2.The activity of catalyst used in reaction has strong relation with its support material. In this work the oxidation of NO to NO2 in the simulated flue gas (NO 550ppm, SO2 2500ppm, O2 4.5% and balance N2) has been investigated over different oxide support materials. The tests of support activities were carried out in a fixed-bed reactor at a space velocity of at least 3000h-1. The effluent gas composition was analyzed by gas chromatography. The SO2 effect on the oxidation pf NO at 150℃ was studied using four different support materials as Al2O3, TiO2, ZrO2 and SiO2.

    An Investigation on Pd-Au-KOAc/SiO2 Catalysts for Vinyl Acetate Production
    YANG Yun-Xin
    2000, 21(S1):  408-408. 
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    Vinyl acetate has recently become one of the important basic organic material.Its present production is 4 million mt/year,it's growth is estimated at a millumum 4%annually to the year 2005.The key technology for the promotion of vinyl acetate for a fixed reaction equipment is the improving of catalyst[1].In this paper, three types of catalysts were made whose active component distribution defferent from each other[2].The distribution of Pd-Au on the catalyst is identified by EPMA.The vinyl acetate fixed bed reactor was used to evaluate the catalytic properties.A transmittance electronic microscope(TEM) was used to generate the appearance maps of Pd-Au distribution on silica carrier;H2 chemisorption for TPR measurements were performanced using a pulse flow system. The paper investigates the effet of Pd-Au distribution on the catalyst dynamics parameter,reaction activity and selectivity,surface appearance and TPR, it is shown that the catalyst whose active components distributing on surface of carrier has better dispersion,higher by-reaction activation energy,low main-reaction activation energy contrasted to egg white and homogenous catalyst TPR results show that non-homogeneous catalyst has two TPR peaks,and homogeneous catalyst has one peak.

    Studies on Gold Electrode Modified by Alkanethiol SAM
    CUI Xiao-Li, JIANG Zhi-Yu
    2000, 21(S1):  409-409. 
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    Self-assembled monolayer (SAM) on gold electrode has been extensively studied in electrochemistry. It is a good model for study the electron transfer through the SAM from metal to redox couple in the solution or tethered on the surface of monolayer. For a pinehole-free monolayer, electron tunneling is considered as the mechanism of electron transfer through the film. The detail of the process in electrochemistry is not clear though there are a lot of publications on SAM research. In this paper,the electrochemical behavior of pinehole-free alkanethiol modified SAM electrode was investigated at different potential in the solution containing various concentration Fe(CN)63-/4- ions. It was found that the apparent resistance could be attributed mainly to the resistance of SAM film.

    Study on Macroscopic Phase State of Dodecyltrimethylammonium Bromide(DTAB)- Sodium Laurate (SL) Mixed System
    XUE Yuan-Ying, GONG Yu-Jun
    2000, 21(S1):  410-410. 
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    By spectrophotometry and TEM images, The macroscopic phase diagram has been drawn and analysed precisely in DTAB-SL mixed system (Fig.l) and the influence of temperature and inorganic salt upon "Aqueous Surfanctant Two-Phase (ASTP)"[1] have been studied systematically.

    Investigation of Propene Oligomerization Catalyst Series Derived from Complex of Ferric Sulfate and Nickel Sulfate
    FAN Hong-Fei, ZHANG Hai-Bo
    2000, 21(S1):  411-411. 
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    Some paper have reported that catalyt of NiSO4/γAlO3 has a very high oligomerization activity for propene, but the over tri oligomerization selectivity is very low[1].The catalyt of Fe2(SO4)3/γ-Al2O3 has a very high over trioligomerization selectivity, but oligomerization activity was lower then catalysis of NiSO4/γ-Al2O3 for propene and stability of catalysis was not as good as catalysis of NiSO4/γ-Al2O3[2].In this paper the catalysis of Fe(2/3)xNi1-xSO4-P2O5/γ-Al2O3 for propene oligomerization has been systematically studied, the effect of the activation method, the stability and reaction conditions on activity and selectivity were investigated. Fe(2/3)xNi1-xSO4-P2O5/γ-Al2O3 catalysis was preparared by impregnation.The factors affecting catalyst performance for propene oligomerization are as follows.

    Low Temperature Oxidative Dehydrogenation of Ethane to Ethylene and Effect of Support over NiO/γ-Al2O3 Catalysts
    CHEN Tong, WAN Hui-Lin
    2000, 21(S1):  412-412. 
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    Some excellent catalysts for ODE reaction,such as K-Sr-Bi-O-Cl[1], LiCl/sulfated-zirconia[2], which have high conversion of ethane and selectivity to ethylene, have been reported recently. But the relatively high reaction temperatures up to 620℃ and/or very low GHSV have been used over above catalyst systems. So the research aimed at searching for new catalysts with good performances at low temperatures appears to be desirable.

    The Determination of Some Physicochemistrical Properties of CA-12 Using Two Phase Titration Technique
    YUE Shan-Tang, WANG Yan-Zhi, CHEN Ming-Zi, HAN Shu-Ming, LI De-Qian, SU Qiang
    2000, 21(S1):  413-413. 
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    Naphthenic acid is a specific, effective extractant to separate yttrium and other rare earth metals and to purify yttrium. But, it has some weaknesses as follows:(1) The extraction separation of yttrium is performed under the condition of higher pH value, thus, the extractant, affected by the impurities of high valence metal ions, is easily emulsified. (2) It is a by-product of industry, so, its quality is not stable. In addition, it has a higher solubility in aqueous solution. (3) The separation factor of lanthanum/yttrium is less and is also affected by temperature, and so on[1].

    A Rapid Method of Measurement Hydrogen Chemisorption on Supported Metal Catalyst
    ZHU Yi-Feng, LI Xiao-Nian
    2000, 21(S1):  414-414. 
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    The surface area and dispersion of a supported metal catalyst can be conveniently determined form the measurement of a chemisorbed monolayer of an appropriate adsorbate such as hydrogen at conditions under which little or no adsorption occurs on the support. Such measurements can be carried out by means of conventional high-vacuum-adsorption apparatus[1],but more rapid flow methods of measuring chemisorption are often found useful[2]. This is especially true when the need arises to characterize the multitude of catalyst samples generated by varying preparation, support, pretreatment and use of a given series of supported metals.

    In situ Confocal Microprobe Raman Spectroscopy and Kinetic Study of Activation of Propane on AgMoO2PO4·MoO3 Catalyst
    ZHANG Xin, WENG Wei-Zheng, YUAN Ru-Ming, WAN Hui-Lin
    2000, 21(S1):  415-415. 
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    As far as the C-H activation of propane is considered, there are many postulations on heterolytic or homolytic C-H bond cleavage. In this work, we investigated the C-H bond activation of propane on AgMoO2PO4·MoO3 catalyst by in situ confocal microprobe Raman spectroscopy and kinetic method.

    In-situ FT-IR spectra of surface Adspecies of Nitrogen or Hydrogen on Ru/MWNTs
    CAI Yun, LIN Jing-Dong, WANG Xin-Ying, LIAO Dai-Wei
    2000, 21(S1):  416-416. 
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    The IR studies on Ru surfaces have revealed important information such as disposition of nitogen[1-3] and adsorption site of H[3-4]. Most of Ru-based catalysts, however, were supported on oxides. In our experiments, Ru was supported on carbon nanotubes and this catalyst has high activity for ammonia synthesis. The experiment was carried out on Nicolet 740 FTIR. The catalyst surface was detected during the processed of temperature-programmed adsorption of N2 and H2) respectively, from 298 K to 773 K. The FTIR spectra of adsorbed H2 and N2 are shown on Fig.l. At 298 K two peaks assigned to adsorbed hydrogen atoms were observed at 2124 and 1564 cm-1. At 673 K, these two peaks shift to 2089 and 1475 cm-1, respectively, and another peak appeared at 1775 cm-1. The peaks at 2124 and 2089 cm-1 can be assigned to the model of H right on top of Ru, and 1564 and 1475 cm-1 may be due to the bridging H. The peak at 1775 cm-1, which can only be observed at high temperature, may be twin-type H. Nitrogen molecularly adsorbed was observed at 1893 cm-1 (298 K) and 1856 cm-1 (673 K) and they can be assigned to liner N2 on top site.

    XPS Spectra of K-Ru/MWNTs Catalysts for Ammonia Synthesis
    LIN Jing-Dong, CAI Yun, SUN Jie, LIAO Dai-Wei
    2000, 21(S1):  417-417. 
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    Alkali metal and alkali oxide-promoted ruthenium has been found to be one of the most active catalysts for ammonia synthesis under atmospheric pressure[1]. Recently, We found[2] that the K-Ru/MWNTs catalyst showed very high activity for ammonia synthesis. It is suggested that the high activity is due to the special electronic and structural properties of the carbon nanotubes. Alkali and alkali oxide doped MWNTs have been reported to be more favorable for electronic transfer and hydrogen storage[3]. In the ammonia synthesis,these properties may play important roles. In this study, K-Ru/MWNTs and Ru/MWNTs were prepared and characterized by XPS. We found that alkali oxide can improve the Ru dispersion similar to the classic catalysts for ammonia synthesis.

    Environmental Catalysis of Vehicle Exhaust Gas:UBI-QEP Energetic Analysis
    SUN Jie, LIN Jing-Dong, WANG Jing, LIAO Dai-Wei
    2000, 21(S1):  418-418. 
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    The Vehicle exhaust gas generally contains nitrogen oxides and the fossil fuel which do greatly harm to air environment. Although the use of catalytic converters for the vehicle gas has resulted in considerable progress in the past twenty years, a theoretical framework for explaining the experimental observations fashion is still lacking. We use the UBI-QEP method[1] to analyze the chemisorbed species and calculate the energies of elementary reactions on following six mental single crystal surfaces:Pt(111),Pd(111), Rh(111),Ag(111),Cu(111) and Ni(111). It will help us to realize the reaction mechanism and choose the best suitable catalysts.

    Chiral Polymeric Coordination Polymer:A Potent Asymmetric Catalyst?
    ZHOU Zhao-Hui, YE Jian-Jun, Deng Yuan-Fu, JIANG Ya-Qi, FANG Zhi-Min, ZHANG Hui
    2000, 21(S1):  419-419. 
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    Owing to the recent environmental consideration and safety concerns,the uses of homogeneous and heterogeneous asymmetric methods for the synthesis of chiral product such as enantioselective hydrogenation are especially preferable.1 Up to now, only a few homogeneous and heterogeneous enantioselective hydrogenation catalytic systems have been investigated in some detail. One of these is the enantioselective hydrogenation of activated carbonyl compounds over a-hydroxy acid modified Raney nickel catalyst.2 Systematic variation of the modifier may prove as an efficient tool to shed light on the reaction mechanism. It has been proposed that tartaric acid adsorbs as a chelate to form binuclear Ni tartarate surface complex. However, the exact adsorption state of the modifier is unknown exactly and requires further attention. Direct investigation of the adsorption mode of the modifier over Raney nickel is not yet possible. Any indirect evidence for the adsorption mode is therefore of crucial importance for a better understanding of the reaction.3

    A Theoretical Study on Electronic Transition of CO Adsorption on Platinum Pt(111) Surface
    WU De-Yin, XU Xin, CAO Zhi-Ji, REN Bin, TIAN Zhong-Qun
    2000, 21(S1):  420-420. 
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    It is now technically possible for Raman spectroscopy to investigate in detail the catalytic reaction on the transition metal surfaces. However, there are only few theoretical papers reported on the contribution of the electronic excited states to the spectroscopic properties. During the interaction of the visible light with the transition metal surface, there exist a number of low-lying excited states due to the unfilled d orbital Nakai and Nakatsuji studied theoretically adsorbed CO on the Pt2 cluster to simulate CO adsorbed on plartinum surfaces.1 However it is known that the cluster with only two platinum atoms is insufficient to simulate CO adsorbed at surface. It is suggested in literature that a good simulated result generally needs to adopt a cluster with more than seven atoms. In this paper, we use a duster with 8 platinum atoms in the surface layer, which has been used by Kua and Goddard to mimic the oxidation of methanol on the Pt(111) surface.2 Based on the interstitial electron model, they found that the cluster is the smallest and the best cluster possible to be used to mimic Pt(111) surface.

    Investigation the Corrosion Process of the Co Electrode by Surface Raman Spectroscopy
    HUANG Zhi-Feng, XIE Yong, REN Bin, TIAN Zhong-Qun
    2000, 21(S1):  421-421. 
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    Due to its special magnetic property, Co has become a very important material in surface science. Furthermore, its unique high catalytic activity has made it an important catalyst for syngas in the catalytic industries. On the other hand, in electrochemistry, Co and its oxides are wide-used electrode materials in the Ni battery and alloy electrodes for hydrogen storage. Thus it is very important to perform the study on the surface process on the Co surface. Raman Spectroscopy is a powerful technique in characterizing the surface species, however Co has been considered as not a suitable material for creating enormous surface enhanced Raman process. Theoretically, it has been reported that Co with suitable particle size could be able to generate weak surface enhancement, but no experimental evidence is available. In this study,we developed a method to roughen the Co surface to create possible enhancement in the Raman signal. Based on that, the oxidation process of the Co surface (or the etching process of the Co surface in electrolytes) was studied. Benzotriazole(BTA), a very typical corrosion inhibitor, was added to the electrolyte to study its effect on the corrosion of the Co electrode.

    Raman Characterization of Organic Monolayers on Silicon Modified by the Electrochemical Method
    LIU Feng-Ming, REN Bin, TIAN Zhong-Qun
    2000, 21(S1):  422-422. 
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    There is a potential interest in directly connecting an organic material with Si,without the existence of interfacial oxide[1]. To date, two different wet-chemical methods have been developed. One is the halogenation/alkylation route (radical reactions), another method is to make use of the reaction between the H-Si surface and 1-unsaturated hydrocarbon that is similar to the standard organic hydrosilylation reactions[2]. It seems that the method of radical reactions could decrease the reaction time and reduce the material consumption. At present, the reaction mechanism involved and the surface structure are still unclear.

    Evaluation of Anticorrosion of NaNO2 on Reinforcing Steel in the Simulated Concrete Solution
    DU Rong-Gui, HU Rong-Gang, FENG Zu-De, WANG Zhou-Cheng, HU Yan-Ying, TAN Jian-Gang, LIN Chang-Jian
    2000, 21(S1):  423-423. 
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    Reinforcing steel in concrete is usually in a passive condition due to the high alkalinity of the pore solution contained in the pores of concrete. However, the passivation may be lost and the corrosion occurs on the steel by a deceased of pH due to carbonation and/or by the penetration of chloride ions which come from the corrosion environment at the metal concrete interface. Pitting corrosion caused by the chloride is most harmful. Corrosion inhibitors can be applied to protect steel in the presence of chloride ions. The anticorrosion action of NaNO2 on the reinforcing steel in the simulated concrete solution containing NaCl has been studied using electrochemical technique and the other methods in this paper.

    Adsorption of Methanol, Formaldehyde and Formic Acid on the Si(100)-2×1 Surface:A Theoretical Study
    LU Xin, ZHANG Qian-Er, LIN M.C.
    2000, 21(S1):  424-424. 
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    Small organic molecules on Si surface serve model systems in studies of the process of SiC, SiO and thin diamond films formation on the surfaces. We have applied the hybrid density functional B3LYP method in conjunction with cluster model approach and the ONIOM method1 to the study of methanol, formaldehyde and formic acid adsorption on the Si(100)-2×l surface.

    Fabrication of Microhole Arrays with Confined Etchant Layer Technique
    SUN Jian-Jun, HUAN Hai-Gou, CHEN Yi-An, YAN Jia-Wei, XIA Shan-Hong, JIANG Li-Min, TIAN Zhong-Qun, TIAN Zhao-Wu
    2000, 21(S1):  425-425. 
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    Drilling holes on materials is a very important technique in both traditional industry and modem science and technology. From fixing two huge workpieces, heat radiating of a turbofan and to fabricating a head of bubble jet printer, they all cannot do without it. Fabricating microhole arrays in micrometer scale or even down to nanometer range is a tough work and is usually performed by anisotropic etching of silicon, ion beam milling and laser ablation techniques, etc. However, they might be confronted the difficulties either in the limitation of the materials for machining or the time-consuming process.

    Electrochemical Oxidation Properties of Benzyl Alcohol on Pt/SPE Electrodes
    MA Chun-An, ZHANG Wen-Kui, HUANG Hui, PAN Hai-Tian
    2000, 21(S1):  426-426. 
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    The electrochemical oxidation properties of benzyl alcohol on Pt/SPE electrodes were investigated using electrochemical methods in this work. As shown in Fig.l,benzyl alcohol could be oxidized on Pt/SPE electrodes, the oxidation peak potential was 1.18 V (vs. SCE) in acetone solution.

    Synthetic Sciences
    Versatile Carborane Cages:A New Class of Metallacarboranes Incorporating the η7-Carboranyl Ligand
    XIE Zuo-Wei
    2000, 21(S1):  427-427. 
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    The chemistry of metallacarboranes has witnessed an explosive growth since the first metallacarborane was reported in 1965. A large number of metallacarboranes of s-,p-, d-,and f-block elements are known; however, the highest hapticity of carboranyl ligands in these compounds has been six. We have recently discovered a brand new bonding mode for carborane molecules, and some recent findings in our laboratory will be presented in this paper.

    Tandem Reduction-Aldol Reactions Induced by Stryker's Reagent
    CHIU Pauline, SZETO Chun-Pong, GENG Zhe, CHENG K.F.
    2000, 21(S1):  428-428. 
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    The incorporation of tandem reactions into a synthetic plan is an important strategy to achieve an efficient synthesis. Consecutive transformations of a substrate in a one-pot synthesis multiplies the complexity of the product while reducing the overall number of steps in the synthetic pathway.

    The Asymmteric Syntheses of Alkaloids via Electro-Oxidation of Aza-Rings
    HU Yen-Yi, RU Wan-Huey, WEI Chao-Jen, LIN Sheu-Jen, LAY Yen-Yuan, YEH Shun-Tsai, YANGTeng-Kuei
    2000, 21(S1):  429-429. 
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    Recently, we found the N-(hydroxyalkyl) aza-rings 1 can produce 2-oxazolidine 2 through electrolysis. With the chiral side chain, the 2-oxazolidine 2 can generate a new chiral center at the 0-aminocarbon when treated with Grignard reagents. Repeat the process of electro-oxidation and substitution by Grignard reagents, we can prepare the two most popular alkaloids bases, pyrroliding and piperidine, with substitutions in an enantioselective fashion. This presentation will discuss the efficiency of electro-oxidation of aza-ring compounds in terms of the oxidation conditions, such as the applied potential, quantity of electricity, solvent effect,and temperature effect. Meanwhile, several demonstrative syntheses of chiral alkaloids, such as Monomorine,(-)-pyrroliding 197B, and(-)-Solenopsin A, will also be presented.

    Asymmetric Synthesis of Efavirenz
    XU Feng, TILLYER Rich, CHEN Cheng Y., TAN Lu-Shi, LISA Frey, ZHAO Da-Lian, GRABOWSKI Ed J.J, REIDER Paul J.
    2000, 21(S1):  430-430. 
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    Recent efforts within the Merck Research Laboratories to discover new compounds for the treatment of HIV infection have resulted in indinavir (Crixivan®), a protease inhibitor, as well as efavirenz, a non-nucleoside reverse transcriptase inhibitor. Efavirenz has shown excellent potency against a variety of HIV-1 mutants when used in combination with Crixivan®, or with other reverse transcriptase inhibitors, and was recently approved for use by the FDA. A practical asymmetric synthesis of efavirenz implemented for large scale manufacture will be presented. The key step in this process involves the highly enantioselective 1,2-addition of lithium cyclopropylacetylide to trifluoromethyl ketoaniline using stoichiometric amounts of lithium (1R, 2S)-N-pyrrolidinylnorephedrate as chiral mediator. A clear understanding of the reaction mechanism based upon extensive low temperature 6Li and 13C NMR spectroscopic studies is achieved. More recent research results on this project will also be presented.

    Planar Chiral Ligands:Design and Applications in Asymmetric Synthesis
    HOU Xue-Long, DENG Wei-Ping, YOU Shu-Li, WU Xun-Wei, DAI Li-Xi
    2000, 21(S1):  431-431. 
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    Chiral ligands play an important role in asymmetric synthesis. Among them the ligands having planar chirality attract more interesting of organic chemists because of their unique structure. Recently, some new types of planar chiral ligands, including 1,1'-disubstituted ferrocene 1, bis(ferrocene carboxylic)diaminocyclohexane 2, and benzylic substituted cyclophane 3, are synthesized (Scheme 1)[1]. These chiral ligands have been successfully used in asymmetric allylic alkylation, Heck reaction, etc. The role of planar chirality in asymmetric induction by using NMR and X-ray are also studied.

    Enantioselective Hydroarylation of Olefins Using Palladium/Chiral Quinoline Oxazolines
    WU Xin-Yan, TANG Fan-Yi, XU Hua-Dong, ZHOU Qi-Lin
    2000, 21(S1):  432-432. 
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    Palladium-catalyzed arylation and alkenylation of olefins, known as the Heck reaction, is one of the most efficient catalytic methods for carbon-carbon bond formation in organic synthesis[1]. During the last decade, asymmetric Heck reactions have attracted great attention, and a number of highly enantioselective chiral ligands have been developed to enhance chiral discrimination in these reactions[2]. However, asymmetric Heck-type hydroarylations of olefins, addition of aryl halides or triflates to carbon-carbon double bonds, have not been well studied. In 1991, Brunner reported an asymmetric hydroarylation of norbornene and norbornadiene with aryl iodides using chiral bisphosphine ligands, and around 40% ee was achieved[3]. Later on, Achiwa reached around 70% ee in the asymmetric hydroarylation of norbornene with phenyl triflate by using chiral P-N ligands[4,5]. Herein, we wish to describe our investigations on chiral quinolinyl-oxazoline ligands that provide the first examples of efficient bisnitrogen ligands in Heck-type hydroarylation and the application of this reaction in the asymmetric synthesis of Epibatidine.

    Asymmetric Borohydride Reduction of Acetophenone Catalyzed by Chiral Salen-Co(Ⅱ) Complex Using Sodium Borohydride
    SUN Wei, XIA Chun-Gu, ZHAO Pei-Qing
    2000, 21(S1):  433-433. 
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    Development of efficient catalytic asymmetric reactions is the most challenging task in current synthetic chemistry; much effort has been devoted to create the chiral metal complexes of asymmetric catalysis. In the last two decades' many brand-new ligands had been synthesized and their combination with various metal ions has been applied in asymmetric catalysis. However, most ligands have only narrow applications and their use is limited to some reactions. Exceptionally, a few ligands and their metal complexes such as binaphthol, semicollin,and binap show wide applicability. Chiral salen ligand is one of such ligands and their metal complexes are now used as the catalysts for a variety of asymmetric reactions such as epoxidation[1], aziridination[2], cyclopropanation[3], Diels-Alder reaction[4], asymmetric transfer hydrogenation of aromatic ketones[5] and kinetic resolution of racemic epoxides[6] and so on.

    The Characterization of the 2,3-Dialdehyde Cellulose Synthesized under Ultrasound Irradiation
    XIONG Jian, YE Jun, HE Xiao-Wei, LI Lin, FAN Pei-Ming
    2000, 21(S1):  434-434. 
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    Partial oxidation of cellulose with sodium periodate (or periodic acid) is one of the most versatile transformations since it provides access to various novel products and intermediates with valuable properties. Moreover, the reaction is a regioselective oxidation of the glycopyranose ring of cellulose, while the glycosidic linkages remain intact. The water insoluble product, 2,3-dialdehyde cellulose without glycopyranose ring,has found considerable interest, for obtaining carriers for enzymes, heparin-like anticoagulation activity, Schiff's base of cellulose, and for the design of advanced materials[1-3].

    Synthesis, Spectroscopic and Structural Characterization of Homochiral Polymeric S-Malato Tungstate(VI) Complex
    ZHOU Zhao-Hui, YAN Wen-Bin, HOU Shu-Ya, MA Zhi-Jie, WAN Hui-Lin
    2000, 21(S1):  435-435. 
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    The S-Malic acid is a natural constituent and common metabolite of plants and animals, being involved in the Krebs cycle and in the glyoxylic acid cycle. Malic acid's metal ion chelating abilities bring about changes in the solubility of metals and influence significantly their mobilization and bioavailability in biological media. Recently, a steady flow of reports on the molecular characterization of tungsten-containing enzyme from a wide range of microorganisms has drastically changed our appreciation of tungsten. Biological tungsten is not an odd remnant of evolution but a widespread, versatile catalytic entity for the activation of the carbonyl group both in carbon dioxide and in a broad spectrum of aldehydes and carboxylic acids. The interaction of tungsten with dicarboxylic acid such as malate may provide a scaffold onto which reasonable hypotheses can be built pertaining to that metal ion's chemical speciation in biological fluids. However, scant information has been available on tungsten dicarboxylate chemistry, with equally unavailable structural data on elusive complexed forms in biological media. The lack of such data prompted us to investigate the tungsten-malate chemistry, targeting low molecular weight complexes soluble in aqueous media.

    Synthesis and Characterization of Three Isomeric Hepta-Nuclear Ruthenium Clusters
    ANG Siau Gek, ANG How Ghee, ZHONG Xin-Hua
    2000, 21(S1):  436-436. 
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    Reactions of 1,2,3,4-tetraphenyl-1,2,3,4-tetraphospholane(Ⅰ) with triruthenium Dodecacarbonyl in 1:2 molar ratio at different temperatures resulted in the cleavage of P-P bonds in Ⅰ to afford three new isomeric heptnuclear ruthenium clusters containing phosphido and phosphinidene ligands with the formula of[Ru7(CO)15(μ4-PPh)2{(μ2-PPH)2CH2}]. All these new obtained clusters have been characterized by elementary analysis, IR, 1H, and 13P NMR spectroscopy methods, and their molecular structures have been established by single crystal X-ray diffraction analysis, Cluster 1 is a chiral molecule alnd two enantiomers (la,lb) are present in it, The structure of 1 is found to contain two square pyramids skeleton sharing a triangular face.

    Synthetic Studies on Halichlorine and Pinnaic Acid. Stereospecific Preparation of the Azaspiro Core Structure
    LEE Sang-Ku, ZHAO Zu-Chun(spring)
    2000, 21(S1):  437-437. 
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    Halichlorine and Pinnaic acid are two novel marine natural products isolated from a Japanese sponge, and an Okinawan bivalve respectively. The unique azaspirl[4.5]decane-core structure prexent in both compounds provides a synthetic challenge, Herein, we describe a synthetic approach to the azaspiro[4.5]decane-core structure through an intramolecular[3+2] cycloaddition followed by an intra-molecular Michael addition and in situ isomerization to afford the azaspirocyclic core structures stereospecifically in 10 steps with 40% overall yield. Alternatively, the same core structure was achieved by tandem cycloaddition and isomerization approach.

    Highly Efficient Enantioselective Synthesis of Optically Active Dihydropyrones by Chiral Titanium(IV) (5,5',6,6',7,7',8,8'-Octahydro-1,1'-Bi-2-Naphthol) Complexes
    FENG Xiao-Ming, WANG Bin, CUI Xin, LIU Hui, JIANG Yao-Zhong
    2000, 21(S1):  438-438. 
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    The formal hetero-Diels-Alder reaction between 1-methoxy-3-(trimethyl-silyl)oxy-1,3-butadiene and aldehydes provides useful access to dihydropyrones, a class of compounds with extensive utility in organic synthesis. Asymmetric catalysis of this reaction has been previously reported by a number of investigators. Herein we wish to describe that chiral 5,5',6,6',7,7',8,8'-octahydro-1, 1'-bi-2-naphthol (H8-BINOL)/Ti(O-i-Pr)4 complexes are more effective catalysts than BINOL/Ti(O-i-Pr)4 and others for the asymmetric hetero-Diels-Alder reactions.

    Synthetic Study Towards the Total Synthesis of Neocarzinostatin Chromophore
    WANG Guang-Xing, IGUCHI Satoru, HIRAMA Masahiro
    2000, 21(S1):  439-439. 
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    The chromophores of enediyne chromoprotein anticancer antibiotics have attracted a lot of efforts towards the total synthesis. Very recently, Myers group[1] reported the first synthesis of neocarzinostatin chromophore 1. The key point of our approach for the total synthesis of this compound is to construct the highly strained and unstable bicyclic[7.3.0]epoxyenediyne core at the late stage of synthesis using an intramolecular acetylide aldehyde ring closure. The proposed approach is illustrated retrosynthetically as follows (Scheme).

    Cyanocuprates as Homo-dimer in Etheral Solution:1H,6Li and 1H,1H Distances Information by NMR
    Ruth M Gschwind, XIE Xiu-Lan, Pattuparambil R. Rajamohanan, Carsten Auel, Gernot Boche
    2000, 21(S1):  440-440. 
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    Despite of the wide application of organocuprates in many areas of organic synthesis, little is known about their detailed structures in solution. Recently we found by NMR that organocuprates in etheral solution exist as an equilibrium between solvent separated ion pairs (SSIPs) and contact ion pairs (CIPs) with the preference of the equilibrium mainly dependent of the solvent properties, and the CIPs as the reactive species. We focus here on 1H, 6Li and 1H, 1H distances investigation by NMR spectroscopy of Me2CuLi(l) and Me2CuLi*LiCN (1*LiCN) in Et2O as models for the structure of salt-free and salt-containing CIPs in solution.

    Photopromoted Carbonylation of Olefins with Carbon Dioxide by Transition Metal Complexes Catalysis
    YIN Jing-Mei, GAO Da-Bin, YU Ye-Cheng, ZHENG Xue-Fang, GUO Ming, GU Yang, WANG Xiang-Sheng, GUO Xin-Wen
    2000, 21(S1):  441-441. 
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    The carbonylation of olefins is important and essential methods to synthesize organic compounds,Which requires high temperature (150-200℃) and high pressure (10~20MPa) in addition to precious metal complex catalysts (such as Ru,Rh, Ir)[1], In recent years photopromoted organic syntheses have received more and more attentions that were called environmentally friendly technique because of their ambient reaction conditions,high reactivities and selectivities and a little pollution[2]. Photopromoted carbonylation can be completed in ambient conditions and by non-precious complexes catalysts, and especially photopromoted methoxycarbonylation of olefins could give better results[3,4]. In previous papers we have established that the methoxycarbonylation of olefins with carbon dioxide could be carried out in place of carbon monoxide.

    Nickel-Catalyzed Hydroesterification of Acetylene with Methyl Formate to Methyl Acrylate in Fixed Bed
    HUANG Xin-Han, YANG Xian-Gui, ZHANG Jia-Qi, LIU Zhao-Tie
    2000, 21(S1):  442-442. 
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    The hydroesterification of acetylene with methyl formate catalyzed by nickel-supported catalysts without any corrosive halide promoter has been comprehensively studied in a fixed bed reactor under various conditions. This reaction can be particularly useful since methyl formate may act as a source of methanol-carbon monoxide, thus simplifying transport and handling[1-3]. The catalysts were prepared by wet impregnation of γ-Al2O3 support with NiCl2 aqueous solution, then dried at 120℃ and calcined at 500℃

    Cation-π Interactions:Synthesis and Crystal Structure of Complex:[Na(DB18C6)]2[Pd(SCN)4]
    LIU Ying, DOU Tian-Min, ZHANG Rong-Lan, DAI Ji-Cui, LI Xue, ZHENG Pei-Ju
    2000, 21(S1):  443-443. 
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    The cation-π interactions have attracted much attention as an important noncovalent binding force. We have synthesized and characterized the first example[K(DB 18C6)]2[Pd(SCN)4] which exist K+-π interactions in crown ether compounds[1]. However,the reported Na+ complexes structurally characterized by X-ray diffraction analysis have so far been limited to a few compounds. We now report the structure of complex:[Na(DB18C6)]2[Pd(SCN)4] which also exist Na+-n interactions.

    Synthesis and Crystal Structure of Complex:[K(DB24C8)(H2O)]2[Pd(SCN)4]0.5H2O
    DOU Jian-Min, LIU Ling, LI Da-Cheng, ZHANG Yu-Kai, ZHENG Feng
    2000, 21(S1):  444-444. 
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    Crown ethers can form complexes with inorganic and organic cations. Much attention has been focused on characterizing the structure of crown ether complexes. However, the X-ray structures of dibenzo-24-crown-8 compelxes:[K(DB24C8)(H2O)]2[Pd(SCN)4]0.5H2O.

    One-dimensional infinite chain crown ether complex:Synthesis and crystal structure of[Na(18C6)]2[Cu(mnt)2]·H2O
    DOU Jian-Min, LI Da-Cheng, LIU Ying, XU Li-Qiang, BI Wen-Hua
    2000, 21(S1):  445-445. 
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    One-dimensional coordination polymers have attracted considerable interest in recent years because of the prospect of electrical, optical and magnetic properties. Crown ether can form one-dimensional infinite chain structure with transition metal complex. We synthesized the complexes of 18-crown-6 with Na2[m{S2C2(CN)2}2](m=Cu, Ni, Pd, Pt; S2C2(CN)22- mnt) and now report the structure of complex[Na(18C6)]2[Cu(mnt)2]·H2O.

    Preparation of Perfluoroalkyl Substituted Saccharides and Their Distribution Ratio between Organic and Fluorous Sovlents
    LI Bing, YU Biao, HUI Yong-Zheng, MA Xing-Quan
    2000, 21(S1):  446-446. 
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    A "fluorous synthesis" approach is outlined in which organic molecules are rendered solublity in fluorocarbon solvents by attachment of a suitable fluorocanbon group. Fluorocarbon sovlents are immisicible in organic solutions, and fluorous molecules partition out of an organic phanse and into a fluorous phase in a standard liquid-liquid extraction. Simple yet substantive separations of organic reaction mixtures are achieved without resorting to chromatography. This methed has been used in many fields, but seldom in oligosacchride synthesis.

    Synthesis of New Phase-Transfer Catalysts and Their Application in Asymmetric Alkylation
    WU Xin-Yan, ZHANG Jie, ZHOU Qi-Lin
    2000, 21(S1):  447-447. 
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    Despite phase transfer catalysis (PTC) is an important and useful method in organic synthesis, asymmetric synthesis using chiral phase-transfer catalyst has not been well documented and limited number of chiral phase-transfer catalyst have been developed[1].In 1989,O'Donnell published his pioneering work in the asymmetric synthesis of α-amino acids by enantioselective alkylation of a prochiral protected glycine derivative using chiral phase-transfer catalyst[2]. Since then, several groups reported their improvements on enantioselectivity and applicability on this useful synthetic reaction[3,4]. However, almost all of the chiral phase-transfer catalysts reported so far are the derivatives of cinchona[5]. In this presentation, we wish to describe the design and synthesis of a new type of chiral phase-transfer catalyst based on the camphor and its application in asymmetric alkylation of tert-bntyl glycinate-benzophenone Schiff base.

    Synthesis of 3-(2-Phenylquinolin-4-yl)/3-(l-p-Chlorophenyl-5-methyl-1, 2,3-triazol-4-yl)-s-triazolo[3,4-b]-1, 3,4-thiadiazine Derivatives
    HUI Xin-Ping, QIAO Ren-Zhong, WANG Qin, GONG Yan-Ni, XU Peng-Fei, ZHANG Zi-Yi
    2000, 21(S1):  448-448. 
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    s-Triazolo[3, 4-b]-1,3,4-thiadiazine derivatives constitute an important class of organic compounds with diverse biological activities. 2-Phenylquinoline and 1,2, 3-triazole derivatives are very attractive heterocyclic systems due to their wide use in medicine, agriculture and industry[1]. Incorporation of 2-phenylquinoline and 1,2,3-triazole moiety into the 3-position of s-triazolo[3,4-b]-l, 3,4-thiadiazine ring system may enhance their biological activity. In light of the above findings, we synthesized some new s-triazolo[3, 4-b]-1, 3, 4-thiadiazine derivatives 2a-b~6a-b by the condensation of 4-amino-5-mercapto-3-(2-phenylquinolin-4-yl)/3-(1-p-chlorophenyl-5-methyl-1, 2,3-triazol-4-yl)-1, 2, 4-triazoles 1a-b with chloroacetalde-hyde, ω-bromo-ω-(1H-1, 2, 4-triazol-1-yl)acetophenone, chloranil, 2-bromocyclohexanone, 2, 4'-dibromoacetophenone, respectively.

    Synthesis and Antibacterial Activities of 7 β-Heterocyclyl-3-(2-substituted 1,3,4-thiadiazol-5-thiometbyl)Cephalosporin
    HUI Xin-Ping, ZHANG Yan, GUAN Zuo-Wu, ZHANG Zi-Yi
    2000, 21(S1):  449-449. 
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    Cephalosporin derivatives are an interesting class of β-lactam antibiotics because of their power against a large number of both Gram-positive and Gram-negative organisms. Many efforts have been made to synthesize cephalosporin by varying the substituents. Further pharmacological research indicated the inhibitory activity, broad-spectrum biological activity and β-lactamase resistance determined by the side chain at 7β position of 7-ACA and the structure of substituted group at C3 position. Actually, most of its applications in clinic are the derivatives linked with heterocyclic at C3 and 7β position of cephalosporin skeleton. Literature[1] also revealed that cephalosporin containing aminothiazoloxime at the 7β position of 7-ACA used as antibiotics with obvious applications. Moreover, some compounds bearing 1,2,3-triazole ring at the C3 position of 7-ACA have been reported to possess better antibacterial activity. For these purpose, we synthesized new cephalosporin 3a-c and 5a-c by the reaction of 7-ACA with 2-arylamino-1,3,4-thiadiazol-5-thioles, and then reacted with 1 -aryl-5-methyl-1H-1,2,3-triazol-4-formyl chloride 2 or aminothiazoloxime active ester 4,respectively.

    Synthesis of 6-(6-/8-Substituted-4-Chloro-Quinoline-3-yl)-3-Aryl-s-Triazolo[3,4-b] -1,3,4-Thiadiazoles
    QIAO Ren-Zhong, HUI Xin-Ping, ZHANG Yan, XU Peng-Fei, ZHANG Zi-Yi
    2000, 21(S1):  450-450. 
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    A survey of literature[1] revealed that s-triazolo[3,4-b]-1,3,4-thiadiazole has received much attention during recent years on account of its prominent utilization as antifugal, anti-inflammatory, analgsic and anthelmintic agents probably resulting from its planner and compact structure. In the course of the study of this ring system, we previously described a series of 3,6-disubstituted-s-triazolo[3,4-b]-1,3,4-thiadiazoles which exhibited antibacterial, herbicidal and plant growth regulative activities. It is well known that quinoline derivatives are associatied with broad spectrum biological activities[2].

    Studies on Reactions of 2-Amino-5-Heterocyclyl-1,3,4- -Thia/Oxadiazole with Acylisothiocyanates
    ZHANG Yan, HUI Xin-Ping, SUN Xiao-Wen, GE Zi-Yi, XU Peng-Fei, ZHANG Zi-Yi
    2000, 21(S1):  451-451. 
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    It is well known that the addition of acyl isothiocyanate with amine formed 1,3-disubstituted thiourea which possess broad spectrum biological activities, Up till now, the addition of 5-heterocyclyl-2-amino-1,3,4-thia/oxadiazole with acylisothicyanate has not been reported. We wish to describe this reaction in this paper. When the new 2-amino-5-(l-p-chlorophenyl-5-methyl-1,2,3-triazol-4-yl)-1,3,4-thiadiazole (Ⅰ) was reacted with acylisothio-cyanates (Ⅱ), not all the compounds were expected acylthiourea (Ⅲ)[1,2], some of them were acid amide (Ⅳ). The formation of the products was determined by the substituents of the acylisothiocyanate. In order to investigate the reaction, we synthesized 2-amino-5-aryl-1,3,4-thio/oxadiazole (Ⅴa,b), and then reacted with 1-p-chlorophenyl-5-methyl-1,2,3-triazol-4-formyl-isothiocyanate (Ⅵ). As it was anticipated, the products only were N-(5-aryl-1,3,4-thia/oxadiazol-2-yl)-N'-(1-p-chlorophenyl-5-methyl-1,2,3-triazol-4-formyl) thiourea (Ⅶa,b) (Scheme).

    Synthesis of 1-aryl-5-methyl-4-substituted-l,2,3-triazoles
    ZHANG Yan, CHU Chang-Hu, QIAO Ren-Zhong, XU Peng-Fei, ZHANG Zi-Yi
    2000, 21(S1):  452-452. 
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    As 1-aryl-5-methyl-4-substituted-1,2,3-triazoles often exhibit broad spectrum biological actions, we have synthesized many heterocyclic and condensed heterocyclic compounds which contained 1-aryl-5-methyl-1,2,3-triazol-4-yl functional groups and screened their antibacterical activities[1,2]. Our further work testified that it was necessary to go on studying such kind of compounds. In order to improve the soluble of these compounds, we chose aniline and p-toluidime as starting materials to synthesize 1-aryl-5-methyl-4-substituted-1,2,3-triazoles 1a-b, 2a-b, 3a-b, 4a-b, 5a, These new compounds all have active reaction groups such as SH, NH2 as well as OH. So they might react with ω-substituted-ω-bromo-acetophenone and 6a-b, 7a-b, 8a-b, 9a were obtained. They are all soluble in hot alcohol. Under similar conditions it is difficult to let 4a-b react completely with ω-substituted-ω-bromo-acetophenone. We only observed a little new compounds by TLC. By Mannich reaction, 1a-b also could react with formaldelyde and p-toluidime and l0a-b were isolated. The evaluation of the biological activity is in progress.

    The Syntheses of Novel 7-Methyl-3-Substituted-1,2,4-Triazolo[3,4-b] benzothiazoles
    DONG Heng-Shan, ZHANG Ji-Yong, TANG Yan-Bo, MAO Xue-Rong
    2000, 21(S1):  453-453. 
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    Tricyclazole is one of the benzothiazole derivatives, which are well known for developing this synthesis as many compounds with this ring system are associated with diverse biological activities such as application as potent antibacterials[1,2] and as fungicides for the control of Piricularia oryzae in the prevention of rice blast[3]. In particular, s-triazolo[3,4-b]benzothiazole derivatives are of interest because of their broad spectra of biological activities. Therefore, it was planned to investigate a system, which combines these three biologic components in a molecule to give a compact system for screening their biologic activities. Recently, we have synthesized a novel 7-methyl-3-substituted-1,2,4-triazolo[3,4-b]benzothiazole from p-methylaniline to 5 with various aromatic carboxylic acids in the presence of phosphorus oxychloride. The structures of these compounds were established by elemental analysis, NMR, MS and IR techniques.

    The Syntheses and Crystal Structure of Novel 5-Methyl-3-Substituted-l,2,4-Triazolo[3,4-b]benzothiazoles
    QUAN Bin, CHAI Er-Feng, MAO Xue-Rong, XU Xiu-Zhi, DONG Heng-Shan
    2000, 21(S1):  454-454. 
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    Novel 5-Methyl-3-substituted-1,2,4-triazolo[3,4-b]benzothiazoles were synthesized from o-methylaniline to 5 with various aromatic carboxylic acids. The yielded product 6a-e was investigated with X-ray crystallographic, 1HNMR, MS and IR techniques. Compound 6e, C24H16N4S,Mi=392.69, crystallized in the triclinic space group PI with unit cell parameters a=9.713(3), b=14.645(4), c=15.641(3)Å, α=113.17(2), β=90.11(2), γ=109.29(2)°,V=1908.1(7) Å3, Z=4, Dm=0.687Mgm-3.

    Syntheses of 3-[5-Methyl-1-(4-Methylphenyl)-1,2,3-Triazol-4-yl]-6-Substituted-s-Triazolo[3,4-b]-1,3,4-Thiadiazoles
    DONG Heng-Shan, LUO Jin-Dong, QUAN Bin
    2000, 21(S1):  455-455. 
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    1,2,3-Triazole derivatives have been reported as inhibiting tumor proliferation, invasion, and metastasis[1]. The fused l,3,4-triazolo[3,4-b]-1,3,4-thiadiazoles derivatives show various biological effects such as antifungal[2], antibacterial, hypotensive and CNS depressant activities[3]. We have reported several 6-aryl-3-[5-methyl-1-(4-methylphenyl)-1,2,3-triazol-4-yl]-s-triazolo[3,4-b]-1,3,4-thiadiazoles in the previous paper[4]. The novel 6-aryl-3-[5-methyl-1-(4-methylphenyl)-1,2,3-triazol-4-yl]-s-triazolo[2,4-b]-1,3,4-thiadiazoles 6a-j have been synthesized by the condensation of 4-amino-5-mercapto-3-[5-methyl-1-(4-methylphenyl)-1,2,3-triazol-4-yl]-s-triazole 5 with various aromatic carboxylic acids in the presence of phosphorus oxychloride. The mercaptotriazole 5 was prepared from 4,the latter being prepared from 1 throng 2 and 3. The title compounds 6 were depicted in scheme 1. The structures of these compounds were established by elemental analysis, NMR, MS and IR techniques.

    Biological Analysis
    The Synthesis And Crystal Structure Of 3-[5-Methyl-1-(4-Methylphenyl)-1,2,3-Triazol-4-yl]-s-Triazolo[3,4-b]-1,3,4-Thiadiazole
    DONG Heng-Shan, XU Xiu-Zhi, QUAN Bin, LUO Jin-Dong
    2000, 21(S1):  456-456. 
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    Likewise the 1,3,4-thiadiazole nucleus which incorporates an N-C-S linkage exhibits a large number of biological activities[1]. The fused 1,3,4-triazolo[3,4-b]-1,3,4-thiadiazoles derivatives show various biological effects, such as antifungal[2], antibacterial, hypotensive and CNS depressant activities[3]. The novel 3-[5-methyl-1-(4-methylphenyl)-1,2,3-triazol-4-yl]-s-triazolo[3,4-b]-1,3,4-thiadiazole 6 have been synthesized by the condensation of 4-amino-5-mercapto-3-[5-methyl-1-(4-methylphenyl)-1,2,3-triazol-4-yl]-s-triazole 5 with formic acid in the presence of phosphorus oxychloride. The compound 5 was prepared from 4 that was prepared from 1 throng 2 and 3. Recently, we obtained the crystal structure of the novel compound 3-[5-methyl-1-(4-methylphenyl)-1,2,3-triazol-4-yl]-s-triazolo[3,4-b]-1,3,4-thiadiazole, C14H12Cl3N7S, Mr=416.72, Crystallizes in the triclinic space group with unit cell parameters a=9.049(2), b=10.486(3), c=10.843(2)Å, α=116.79(2), β=93.83(2), γ-100.64(3)°. V=889.3(4)Å3, Z=1, Dx-0.778 Mgm-3. The final R was 0.0535.

    Synthetic Sciences
    Enantioselective Construction of the Oxidized Tryptophan Fragment of TMC-95A and TMC-95B
    MA Da-Wei, WU Qing-Quan
    2000, 21(S1):  457-457. 
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    TMC-95A-D are four cyclic peptides containing L-tyrosine, L-asparagine, highly oxidized L-tryptophan, (Z)-1-propenylmine and 3-methyl-2-oxo-pentanoic acid units. These compounds were recently isolated from the fermentation broth of Apiospora montagnei Sacc.TC 1093,isolated from a soil sample. Biological studies indicated that these natural products, especially TMC-95A, exhibit potent inhibiting activity towards proteasome (IC50=5.4 nM). In this report, a stereocontrolled synthesis of the oxidized tryptophan fragment of TMC-95A and TMC-95B is described. Key steps include the condensation of the lithiated oxindole with D-Gamer aldehyde and subsequent dihydroxylatioa of the carbon-carbon double bond.

    Synthesis of Some New Pyrazolopyrimidines and Pyrazolotriazines
    HU Fang-Zhong, ZOU Xiao-Mao, LU Rong-Hua, YANG Hua-Zheng
    2000, 21(S1):  458-458. 
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    In view of the biological activities of 5-aminopyrazoles, e.g. tranquilizing and analgesic properties, some of new fused pyrazolopyrimidines and pyrazolotriazines were synthesized. 5-Amino 3-substituting group 4-cyano (or ethoxycarbonyl) pyrazoles 2 were prepared via the reaction of 1 with hydrazine hydrate in ethanol at room temperature (Scheme 1).

    A Novel, General Approach for the Synthesis of Benzimidazole-2-yl Phosphonate
    HU Fang-Zhong, ZOU Xiao-Mao, YANG Hua-Zheng, WENG Lin-Hong
    2000, 21(S1):  459-459. 
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    The increasing and sustained interest has been paid to organophosphorus chemistry in the past decades owing to the discovery of more and more naturally occurring C-P compounds, which show antibacterial, antiviral, antibiotic, pesticidal, anti-cancer activity. On the other hand, heterocyclic confounds attract the attention of chemists because of their pharmaceutical importance and various applications in organic synthesis. Three building blocks, α,α-dicyano (α-cyano-α-ethoxycarbonyl) (O, O-dialkyl) phosphonyl/S-methyl ketene acetals and N-cyanoimido-(O, O-dialkyl)phosphonyl/S-methyl thiocarbonates 1,have been developed. To the best of our knowledge, there are no reports on the synthesis of benzimidazole-2-yl phosphonates, which are prepared easily by utilizing above building blocks.

    Synthesis and Biological Activity of Pyrazolo[5,1-d] [1,2,3,5]-Tetrazine-4-ones
    HU Fang-Zhong, ZOU Xiao-Mao, LI Yong-Hong, YANG Hua-Zheng
    2000, 21(S1):  460-460. 
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    It is reported that benzo[1,2,3]-triazine-4-ones have widespread use, for instance, as diuretics, sedatives, tranquilizers and inflammation inhibitors and pyrazolo[1,5-a]-1,3,5-triazines are potent inhibitors of xanthine oxidase. So far,the herbicidal activities of above fused ring compounds and their analogues have not been studied. According to the principle of bioisotherism, pyrazolo[5,1-d] [1,2,3,5]-tetrazine-4-ones (2) have been developed and synthesized.

    A Highly-ordered, Self-assembled Aggregate Driven by Hydrogen Bonding
    HU Fang-Zhong, ZOU Xiao-Mao, YANG Hua-Zheng, WENG Lin-Hong
    2000, 21(S1):  461-461. 
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    Hydrogen bonds, with their moderately directional characteristics and predictable patterns, are especially useful instructions, and their incorporation in molecules has resulted in a spectacular array of assemblies:Molecular ribbons, tapes, sheets, cages, rosettes, cubes, and capsules have been designed, synthesized, and characterized, both in solution and in the solid state. For example, Wyler, de Mendoza and Rebek have extended the range of architectures that have been self-assembled by hydrogen bonds.

    Conversion Natural Gas to Ci Hydrocarbons via Cold Plasma Reaction
    WANG Bao-Wei, XU Gen-Hui
    2000, 21(S1):  462-462. 
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    Natural gas is not only an increasing important role in energy and chemicals supplies in 21st century but also the second most important of the greenhouse gases[1]. For the past 200 years atmospheric methane concentrations have increased from 0.8 to 1.65ppm. This change in methane concentration had been led to an estimated increase in radiative forcing of climate of 0.47 W/m2 compared to the increase of 1.56 W/m2 due to the change in carbon dioxide concentration over a comparable time period[2]. With large increases in natural gas reserves proven worldwide, it can be expected that natural gas will play an increasing important role in humanity future. Cold plasma chemical processing is a promising route for synthesis of chemicals that have high activation energies, because electric field can be excite reactant to the plasma and many kinds of reactive particles, electrons, free radicals, ions metastable species and photons are produced in a plasma chemical processing system.

    Syntheses and Complexing Properties of Polyethers
    SONG Hua-Can, LI Wei-Ming, CHEN Yi-Wen, ZOU Yong-De, XUE Zun-Le, Jerald S. BRADSHAW, ZHANG Xian-Xin, Paul B. SAVAGE
    2000, 21(S1):  463-463. 
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    Diaza-18-crown-6 with two 8-hydroxyquinolines as side arms show high selective complexing ability with metal ions[1,2] and with two aminophenols exhibit strange property[3]. 8 diaza-18-crown-6 ethers containing sidearms[4] and 7 podands were synthesized. Their complexing ability with metal ions were studied, the results show that they present high complexing capability for metal ions. The polyethers containing 8-hydroquinoline fragment show high selectivities for Hg2+,Ni2+ and their complexes with Eu3+ and Tb3+ show strong luminescence.

    Study on Atom Economic Process of Diethyl Oxalate Synthesis by CO Coupling in Gaseous Phase
    WANG Bao-Wei, MA Xin-Bin, XU Gen-Hui
    2000, 21(S1):  464-464. 
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    The gaseous phase syntheses of diethyl oxalate and oxalic acid from CO are an important project of chemical technology[1]. Oxygencontent of CO is as high as 57%(wt) and its source is abundant. It is best of all economical and reasonable that oxy-compound is synthesized with carbon monoxide. In particular the reaction of CO coupling reaction can take place under moderate reaction conditions with low consumption of energy to produce oxalic acid and diethyl oxalate, which are feed stocks for ethylene glycol syntheses by the hydrogenation of oxalate, as well as for products such as pesticides, pharmaceuticals, foodstuffs, polymers, and fine chemicals.

    A Convenient Method for Synthesis Methyl Ester of Naproxen
    LI Yan-Yun, XIA Chun-Gu
    2000, 21(S1):  465-465. 
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    α-Arylpropionic acids are a class of nonsteroidal anti-inflammatory drugs with a substantial size of market. Ibuprofen and naproxen are the important members of this family. Since carbonylation catalyzed by transition metal complexes provides an environmentally benign process for their synthesis, there have been numerous patents and publications related to the carbonylation of alcohols and olefins to produce α-arylpropionic acids or their esters[1-4]. We have studied the carbonylation of α-(6'-methoxy-2'-naphthyl) ethanol to methyl ester of naproxen using PVP-PdCl2-CuCl2/PPh3 catalyst system. Good conversion and selectivity were obtained under mild conditions.

    Study on the Acid Treatment of Titanium Silicalite TS-1
    GUO Xin-Wen, WANG Xiang-Sheng, LIU Min, YAN Hai-Sheng, CHEN Yong-Ying, XIU Jin-Hai
    2000, 21(S1):  466-466. 
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    Titanium silicalite (TS-1) is one kind of heteroatom molecular sieve synthesized by Taramasso and his coworkers in 1983[1]. Its specific catalytic oxidation properties have attracted much attention of many scientists[2]. The synthesis of TS-1 need use expensive TPAOH as the template; this restrains its industrial application. There are many reports on low cost TS-1, such as using TPABr to replace TPAOH, silica sol to replace tetra-ethyl orthosilicate[3-5]. In our lab, TS-1 was synthesized by using TPABr as the template and silica sol as silicon source,and the amount of TPABr was decreased to 0.05 (TPABr/SiO2). The as-synthesized TS-1 has some differences compared with TS-1 synthesized according to the standard method, such as large crystal size, trace aluminum, extra-framework titanium, high activity in the epoxidation of propylene with dilute H2O2 and low selectivity of propylene oxide (20-30%). The low selectivity of PO is attributed to the acidity of TS-1 resulted from the trace aluminum and silicon hydroxyl. In order to increase the selectivity of PO, it is necessary to add some base to the reaction mixture. Generally, acid treatment can remove aluminum and other elements and impurity to improve catalyst. In this paper, the effect of the acid treatment on the physicochemical properties of TS-1 was studied.

    Facile Synthesis of (z)-5-Methyl-3-Phenoxymethylene 4,5-Dihydrofuran-2-One
    LIU Li-Jun, LUO Fentair
    2000, 21(S1):  467-467. 
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    (z)-α-Alkylidene-α-butyrolactone has been reported as a good plant growth regulator[1] and as an important intermediate to the synthesis of natural product[2] in literature. There was no report in the literature for the stereoselective synthesis of α-alkylidene lactones in exocyclic double with the (z)-configuration. Herein, we reported a facile synthesis of (z)-5-methyl-3-(phenoxymethylene)-4,5-dihydrofuran-2-one 4 from a readily available starting material 5-phenoxypent-3-yn-2-one 1 via three-step in good yield. The synthetic route is shown as below (scheme 1).

    Racemization of R-Naproxen Ester Using Microwave Oven
    XU Yi, XIN Jia-Ying, LI Shu-Ben, WANG Lai-Lai, XIA Chun-Gu
    2000, 21(S1):  468-468. 
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    (S)-(+)-2-(6-methoxy-2-naphthyl) propionic acid (Naproxen) is a nonsteroidal antiinflammatory drug which belongs to the family of 2-aryl propionic acid derivatives, which is widely used as a drug for human connective tissue diseases. The physiological activity of the S-form Naproxen is 28-fold that of the R-form[1]. Hence, only the S-form is used as a drug for human diseases.

    Study On Dimethyl Carbonate Synthesis from Methyl Nitrite And CO1
    MA Xin-Bin, WANG Bao-Wei, XU Gen-Hui
    2000, 21(S1):  469-469. 
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    Recently, dimethyl carbonate (DMC) has attracted much attention as a less toxic reagent in relation to environmental problem. DMC is a novel reagent for methylation and carbonylation in place of toxic dimethyl sulfate and phosgene, respectively. DMC is also a promising fuel additive because it can improve octane number.

    Synthesis of Crownary Tetra-Schiff Base Macrocycle Compound
    SUN Bin, HUANG Yu-Lin, LI Rui-Xiang, CHEN Hua, LI Xian-Jun
    2000, 21(S1):  470-470. 
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    The Robson type ligands and their complexes are of interest as models of biomolecules. They have been prepared and widely studied since 1970[1-3]. If a Schiff base ligand contains crown ring and it coordinates to a metal ion, the special steric structure of crown can greatly influence on the properties of complex, such as magnetic interactions. So we designed and synthesized crownary tetra-schiff base macrocycle (H2L). The synthetic route is shown in Fig.1.

    Biomimetic Oxidation of 1-1'-Bi-2-naphthol with Copper(Ⅰ) and Copper(Ⅱ)-amine Complexes
    TAN Duan-Ming, LI Hui-Hua, XU Zun-Le
    2000, 21(S1):  471-471. 
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    Copper amine complexes were used to mimic oxidases in the biomimetic oxidation of organic compounds[1]. Masahiro Noji and coworkers[2] reported the oxidative coupling of 2-naphthol into high yield of 1,1'-bi-2-naphthol (1) by using catalytical amount of CuCl-tetramethylethylenediamine complex at the presence of O2. Here we report the catalytic oxidation of 1 with copper amine complexes.

    Synthesis of Chiral 1,3-Bis(oxazolinyl)benzene
    GAO Ming-Zhang, XU Zun-Le
    2000, 21(S1):  472-472. 
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    In recent years, C2-symmetric chiral bis (oxazoline) ligand-metal complexes have received a great of attention through their use in various catalytic processes[1-2]. Since the early 1990s, many impressive enantioselective carbon-carbon bond forming reactions, aziridination reactions, hydrosilylations, oxidations and reductions have been recorded using bis (oxazoline)-metal complexes with wide structural diversity[3-4]. The latest review is intended to focus on the recent developments of bis(oxazoline) ligand-metal catalyzed asymmetric reactions and their applications in organic synthesis. Herein we intend to report the synthesis of a new type of chiral bis(oxazoline), 1,3-bis(oxazolinyl)benzene. Application of their asymmetric catalysis is under working.

    Synthesis of β-Pinene/THF Block Copolymers
    LU Jiang, LIANG Hui, LI Bao-En
    2000, 21(S1):  473-473. 
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    The living cationic polymerization of β-pinene was carried out with α-chloroethylbenzene(PEC)/TiCl4/Ti(OiPr)4 initiating system in CH2C12 at -40℃. After 25 min of reaction(β-pinene conversion~100%),the resulted living poly(β-pinene) was capped with a few units of styrene and then the polymerization was quenched to give β-pinene macroinitiator with benzenyl chloride chain end (P(β-p)-St-Cl). The structure of the macroinitiator was confirmed by 1H NMR (Fig.l). The macroinitiator, in conjunction with AgSbF6 or AgC1O4,was used to initiate the ring-opening cationic polymerization of THF in the presence of propylene oxide promoter. GPC analysis of the obtained polymers showed that AgSbF6 system led to almost pure block copolymers of β-pinene with THF, whereas AgC1O4 system gave mixtures of block copolymers and low molecular weight homopolymers of THF and unreacted macroinitiator (Fig.2). 1H NMR analysis further confirmed the formation of β-pinene/THF block copolymers with macroinitiaor/AgSbF6 system (Fig.3).

    Stereoselective Synthesis of α-Altropyranosyluridine Starting from Glucose
    CHENG Chang-Mei, HERDEWIJN Piet, ZHAO Yu-Fen
    2000, 21(S1):  474-474. 
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    α-Nucleoside is a kind of potential antiviral and antitumor agent, and of great interest in antisense and template directed reaction. β-Altropyranosyl-nucleosides have been synthesized and the properties of their oligo-nucleotides have been studied by Eshenmoser[1]. But it is very difficult to synthesize the α-anomer, because the direct coupling reaction leads to the β-anomer and the cyanamide route is not suitable due to the trans-configuration of 1,2-dihydroxyl groups in α-altrose. In order to resolve this problem, α-2, 1'-anhydroglucopyranosyluridine was synthesized by cyanamide route and it was hydrolyzed to title compound in good yield with 2',3'-configuration reversion.

    Photochemical Synthesis of Cyclopentadienyl-hexamethylbenzene-iron Tetrafluoborate
    CHEN Xu-Dong
    2000, 21(S1):  475-475. 
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    As a new type of photoinitiator, cyclopentadienyl-aryl-iron tetrafluoroborate has received much attention[1]. We[2] have improved the synthesis method of cyclopen-tadienyl-benzene-iron tetrafluoroborate reported by the literature[3,4]. This synthetic method is to reflex the mixture of ferrocene and fluid aromatic compound; the cyclopentadiene of ferrocene was replaced by the incoming aromatic compound. However, this method is rather limited if the ligands are solid aromatic compounds.

    Kinetic of Excimeric Formation of Sulfonated Polystyrene
    CHEN Xu-Dong
    2000, 21(S1):  476-476. 
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    Many vinyl polymers with aromatic chromophores exhibit intramplecular excimer fluorescence in solution[1,2]. Investigation of the fluorescence of excited chromophores bound to polymers can provide information about the interaction of chromophores and the microenvironment surrounding the chromophores. Here we describe the kinetic of excimeric formation of sulfonated polystyrene (SPS).

    Study on the Ring-opening of α-L-arabinopyranoside Benzylidene Acetals
    WEI Xiao-Mei, GAO Li-Ming, CHENG Dong-Liang, SHEN Zheng-Wu
    2000, 21(S1):  477-477. 
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    OSW-1 was isolated from the bulbs of Ornithogalum saundersiae by Satoshi Kubo of Japan in 1992,which is 100 times more potent than other anticancer agents available in clinical use,such as CTP and TAX. The oligosaccharides of OSW-1 is composed of 2-O-acetyl-α-L-arabinopyranoside and 2-O-4-methoxybenzoyl-β-D-xylopyranosyl by 1-3. We study on the Synthesis of the oligosaccharides of OSW-1. Now we suggest the possible pathway of 2-O-acetyl-α-L-arabinopyranoside, especially study on the ring-opening of its benzylidene acetals.

    Study on Oxidation of A Mimic Enzyme[Mn2IV(μ-O)3(Me3TACN)2](PF6)2·H2O Complex
    WEI Xiao-Mei, GAO Li-Ming, CHENG Dong-Liang, SHEN Zheng-Wu
    2000, 21(S1):  478-478. 
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    It is well established that mangamese is an essential trace element in biology. The oxidation of water by photosynthetic enzymes (photosystem Ⅱ; PS Ⅱ), the reduction of ribonucleotides in certain bacteria, and the disproportionation of hydrogen peroxide by some catalases or pseudocatalases have been shown to occur at bi-or polynuclear manganese containing active sites[1]. Manganese complexes derived from 1,4,7-trimethyl-1,4,7-triazacyclononane and related ligand systems act as highly effective catalysts for the bleaching of stains by hydrogen peroxide at low temperatures. These complexes also catalyze the epoxidation of alkenes and the oxidation of polyphenolic substrates by hydrogen peroxide[2]. So far, the paper for the oxidation of[Mn2IV (μ-O)3(Me3TACN)2](PF6)2&#H20 83;(Mn2IV-cat) is little. In our work, We use various alkene, pregnenolone, aromatic aldehydes and toluene series as substrates, Mn2IV-cat. catalyze the epoxidation of alkenes; the epoxidation and the oxidation of allylic position of pregnenolone; the oxidation of aromatic aldehydes and toluene series respectively (see the following table).

    Synthesis, Characterization and Biological Activities of Bis(tributyltin) Dicarboxylates
    ZHANG Ru-Fen, YIN Han-Dong, MA Chun-Lin
    2000, 21(S1):  479-479. 
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    Organotin carboxylates are widely used as biocides and in industry as homogeneous catalysts. In order to allow exploration of relationships between their biolgical activities and structure, a number of investigations on such molecules have been reported in recet years. In our early work, the organotin hetercyclic carboxylates, dithiopiperidyl carboxylates and alkynyl phosphates were synthesized, their structure and biological activities were studied also. Up to now, the bis(organotin) dicarboxylate were reported very little.

    Synthesis and Properties of Di-and Triphenyltin Derivatives of Alkynylphosphonic Acid
    ZHANG Ru-Fen, YIN Han-Dong, MA Chun-Lin
    2000, 21(S1):  480-480. 
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    Previous reports in this series have described the syntheses of di-or tribenzyltin(IV) and di-or tributyltin(IV) derivatives of alkynyl or alkenyl phosphonic acid. These studies were directed toward developing the basis for more powerful biocidal activity through dual-acting compounds incorporating both organotin and organophosphorus moieties in the same molecule.In this paper, di-and triphenyltin(IV) derivatives of alkynyl phosphonic acid were synthesized by the action of the coresponding phenyltin(IV) chlorides with die alkynyl phosphates.

    Synthesis and SpectroscOpic Charcterization of Di-and Triphenyltin Derivatives of Dithiocarbomatic Acid
    YIN Han-Dong, WANG Chun-Hua, MA Chun-Lin
    2000, 21(S1):  481-481. 
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    A series of triphenyltin dithiocarbamates Ph3SnS2CNR2, where NR2=NMe2,-NEt2, N(pr-n)2,-N(CH2CH2OH)2, and diphenyltin derivatives of dithiocarbamatic acid Ph2Sn(S2CNR2)2,where NR2=NMe2,-NEt2,-N(Pr-n)2,N(Bu-n)2, N(CH2CH2OH),were synthesiced by the action of the correspending phenyltin (Ⅳ) chlorides with dithiocarbamates in dichloromethane. Their structure were characterized by elemental analysis, IR, HNMR and MS.

    Synthesis and Antitumor Activity of Diphenylgermanium Derivatives of Heterocyclic Carboxylic Acid
    YIN Han-Dong, WANG Chun-Hua, MA Chun-Lin
    2000, 21(S1):  482-482. 
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    In recent years, the diorganotin derivatives of carboxylic acid was extensively studied due to their antitumor activity. Up to now,the synthesis, characterization and biological activity of organogermanium heterocyclic carboxylate have not been studied. In this work, the sixteen new diphenylgermanium derivatives of heterocyclic carboxylic acid were synthesized by the reaction of diphenylgermanium dichloride with sodium solts of heterocyclic carboxylate in 1:1 or 1:2 molar ratio.

    Synthesis, Charcterization and Properties of Chlorodiphenylgermanium Dithiocarbamates
    YIN Han-Dong, WANG Yong, MA Chun-Lin
    2000, 21(S1):  483-483. 
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    Organostannane and organosilane derivatives of dithiocarbamate are well-known. By contrast, analogous organogermanium compounds have not been studied.

    Synthesis and Characterization of Bis(triphenylgermanium) Dicarboxylates
    YIN Han-Dong, WANG Yong, MA Chun-Lin
    2000, 21(S1):  484-484. 
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    In recent years, the chemistry of organotin and organogermanium compounds was extensively studied due to their biological ativity. In our early work, the organotin carboxylate, dithiopiperdylcarboxylate and alkynyl phophate were synthesized. Their structure and biological activity were studied also. Up to now, the organgermanium carboxylate were reported very little, but bis(triorganogermanium) dicarboxylate have not been reported. In this work, bis(triphenylgermanium) dicarboxylates were synthesizd by triphenylgermanium chloride with dicarboxylates in 2:1 molar ratio. Their structure were characterized by elemental analysis, IR, 1H NMR and MS.It is showed that the carboxylate group act in a monodentate fashsion similar to that found for the tin analgue.

    Study on the Dissociation Kinetics of the Complex of Yb(Gly-Gly)2Cl3·3H2O
    LI Rui-Ping, CHEN Bai-Ling, FAN Qiong-Fang, GUO Jian-Xun
    2000, 21(S1):  485-485. 
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    Rare earth metals have been extensively used in industry, agriculture, medical and breeding enterprises, which will let the possibilities of rare earth ions entering the animals, plants and human bodies increased. It is necessary to investigate their physiological effects and coordination with living ligands in organisms. In the actual living systems and the application fields of rare earth complexes, not only are the existing forms of the complexes in organisms considered, but also the dissociation rates of them are considered too. In order to investigate the distribution, accumulation and metabolism of rare earth in living things, we have been studied the dissociation kinetics of the complex Yb(Gly-Gly)2Cl3·3H2O in various media of pH at different temperatures based on our previous work. We have drawn the conclusion that the dissociation reaction is first order on the titled complex in pH2.27 with maximum absorption at 209nm, and the dissociation rate was increased with the increasing temperature. The complex wasn't dissociated in the media of pH2.75, 4.00,5.00, 6.00, i.e. the complex is stable in the pH range encountered physiologically (bordering neutrality).

    Solid-state Synthesis of Aryl and Vinyl of Ferrocene Derivatives via Wittig Reaction
    LIU Wan-Yi, XU Qi-Hai, LIANG Yong-Min, MA Yong-Xiang
    2000, 21(S1):  486-486. 
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    Organometallic structure possessing extensively conjugated π-electron system are an interesting class of potentially highly nonlinear molecular blocks and photoactive semiconductor[1,2]. The title compounds were synthesized following Wittig reaction or palladium-catalyzed reaction of olefines and iodoferrocene, which proceed in solution and refluxing[3]. However, there are always some disadvantages such as long reaction time, difficult work-up and low yield. Herein we report a free-solvent synthesis of aryl and vinyl ferrocene derivatives. As shown in the table, the phosphoning salt (1mol),NaOH (1.5mol) and formylferrocene (1mol) were mixed by grinding at room temperature to 65℃ in dry state to give the corresponding title compounds in 60-90% yield. The reaction was usually completed within a few minutes. The product thus obtained is mainly E-isomer. It could be emphasized that solid-state Wittig reaction is fast, cleaner and efficient.

    Biological Analysis
    The New Synthesis of Substituted Thiosemicarbazones-Appended Ferrocenyl Group via Solid-state Reaction
    LIU Wan-Yi, XU Qi-Hai, LIANG Yong-Min, MA Yong-Xiang
    2000, 21(S1):  487-487. 
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    The thiosemicarbazones appended ferrocenyl fragment have various biological activities and are useful in ultraviolet absorber and preparing multimetallic redox-active complexes[1,2]. The usual method for the preparation of such kind of compounds involves treatment of acylferrocene with thiosemicarbazide in an acidic absolute ethanol solution refluxing for several hours. However, there were always some disadvantages such as long reaction time, difficult work-up and low yield. Herein we report a facile synthesis of substituted thiosemicarbazones appended ferrocenyl group via solid state reaction. As shown below,formylferrocene or acetylferrocene is treated with several thiosemicarbazides under TsOH catalyses at 70℃ in dry state to give the corresponding title compounds in 82~91% yield. The reaction was usually completed within 30 min. Compared to the reported literature, the main advantages of the present procedure are as following:shorter reaction time, higher yield, cleaner reaction with easier work-up.

    Synthetic Sciences
    Palladium-Catalyzed Carbonylative Reaction of Iodine Heterocyclic Compound with Alcohol
    LUO Sheng-Jun, LIANG Yong-Min, MA Yong-Xiang
    2000, 21(S1):  488-488. 
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    In the past few decades, much attention has been focused on palladium-catalyzed carbonylative reactions[1,2], which is a simple method to synthesize some complicated compounds[3,4]. This kind of reactions, however, can be carried out only when the substrates are arylhalide, heteroaryl halide, alkene halide,aryltrifluoromethyl-sulfonate and hypervalent iodonium salt[5] etc. Herein, we report a palladium-catalyzed carbonylative reaction between 3,7-bis(N,N-dimethylamino)-10H-dibenz[b,e] iodinium iodide(1)[6] with alcohols (2) at ambient temperature as shown in scheme.

    A Study of Structure and Catalytic Activity of Ag-Fe Mixed Oxide Catalysts for CO oxidation
    CHEN Min, ZHOU Ren-Xian, ZHENG Xiao-Ming
    2000, 21(S1):  489-489. 
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    Much effort is made to reduce CO to environment pollution[1]. The precious metal (such as Pt, Pd, Rh) are well known to apply in the total oxidation to treat with the exhaust gas emission and CO, which have good situation in high activity and stability[2]. Due to the high cost and limited availability of precious metal, people become more and more interested in searching base metals to replace precious metal, especially,transition metal oxide catalysts. In our study, the results indicate that the Ag/Fe (1:1) catalyst exhibits highest active to CO oxidation. It is detected that the highly dispersed state of σ-AgFeO2 is the active site for CO oxidation.

    Synthesis of New Type Azo Compounds 2-Aroylazo-5-aryl-1,3,4-oxadiazole
    WANG Xiao-Yang, CHANG Su-Ping, ZHANG Zi-Yi, WANG Yu-Lu
    2000, 21(S1):  490-490. 
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    Azo Compounds are important for their uses as dyes and analytical reagents. Optical-switch and image storage can be made by azobenzenes liquid crystal Recently, scientists are especially interested in new type azo compounds fir they can be used as photoconductive and photochromism materials. However these kinds of azo compounds were limited because of the limited synthesis methods.

    Synthesis of Novel Derivatives of 4'-Demethyl-epipodophyllotoxin
    ZHANG Fu-Min, TIAN Xuan
    2000, 21(S1):  491-491. 
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    Etoposide and Teniposide are used clinically in the treatment of various cancers, but their low solubility in water and high toxicity have being stimulated people to synthesize new active analoges. 5-fluorouracil (5-Fu) has been shown to be active in the treatment of rectal cancer, colonic cancer and matadenoma for fourty years. Because of obvious first-pass metabolism and low lipophilicities, its activity of antitumor have been decreased. A number of experiments showed that the drug must permeate the member of cell and bring into effect of drug. Considering the synergy effect of drugs, we had synthesized four novel etoposide analoges.

    Dimerization of Incomplete Cubane-Type Mo3S4(DTP)3 Units Linked by Bridging α, ω-Dicarboxylate
    TANG Yan-Hong, WU Ling, QIN Ye-Yan, KANG Yao, LI Zhao-Ji, YAO Yuan-Gen
    2000, 21(S1):  492-492. 
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    Since the trinuclear molybdenum cluster compound Mo3S4(DTP)3(μ-DTP)(L) (DTP=diethyldithiophosphate, L=loosely-coordinated ligand) was reported[1],a large number of monomeric trinuclear molybdenum derivatives have been synthesized from it by its diverse substitution reactions[2]. This reaction provides a useful route to design cluster complexes with specific functions. By the reaction with α, ω-dicarboxylates, we successfully synthesized the first oligomer containing two incomplete cubane-type[Mo3S4] cores formulated as[Mo3S4(DTP)3(DMF)]2[η2-μ-OOC(CH2)3COO-μ-η2]) whose molecule structure is as follows:

    Synthesis and Crystal Structure of Molybdenum-Sulfur Cluster Compounds Coordinated by Nicotinic Acid and Isonicotinic Acid
    QIN Ye-Yan, WU Ling, TANG Yan-Hong, KANG Yao, LI Zhao-Ji, YAO Yuan-Gen
    2000, 21(S1):  493-493. 
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    Cuboidal Molybdenum have been paid much attention due to their structural resemble with those metallic centers in some biological systems[1]. To explore the chemistry of trinuclear Mo-S cluster complexes[2], we rationally synthesized two compounds:Mo3S4(DTP)3(nicotinate)(Py)·EtOH (Ⅰ) (DTP=diethyl dithiophosphate) and Mo3S4(DTP)3(isonicotinate)(Py)·EtOH (Ⅱ) by the substitution reaction of Mo3S4(DTP)3(L)(Py) (L=ClCH2COO-, CH3COO-) with nicotinic acid and isonicotinic acid, respectively.

    The Synthesis of Ferrocenyl Compounds with Nonlinear Optical Properties
    XIE Tong, WU Xiao-Li, LIU Wan-Yi, GAO Shi-Yang, MA Yong-Xiang
    2000, 21(S1):  494-494. 
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    There is currently considerable interest in the synthesis of new material with large second-order optical nonlinearities[1-2]. Ferrocenyl derivatives that we synthesized should offer the nonlinear optical properties because they possess (-donor acceptor interactions and non-centrosymmetry. In these compounds, ferrocenyl moiety is strong donor and pyridinium moiety can provide low-lying (* acceptor orbitals. Furthermore, these ferrocenyl compounds may also be used in preparation of self-assembled monolayers (SAMs)[3] due to their long alkyl chain that can be anchored on metal oxide by carboxylic group. The synthesis of ferrocenyl derivatives is shown in Scheme 1.

    Convenient Synthetic Route to (±)-Frontaliu
    GAO Zhu-Lin, YIN Cai-Xia, LIU Fu-Chu, ZHU Hong-You
    2000, 21(S1):  495-495. 
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    Frontalin, the pheromone of Dendroctonus Bark Beetles, was first isolated by Kinzer[1] from hindgut extracts of male western pine beetles. Its structure was determined as 1,5-dimethyl-6,8-dioxabicyclo[3.2.1] octane (1) by spectral analysis and was confirmed by the synthesis of its racemate[1,2]. On account of its structural novelty and economic value, this compound has been studied extensively [3-5]. But most of its synthetic methods required relatively longer steps or suffered from the inaccessibility of starting materials or reagents. Now, we report a convenient synthetic method for (±)-frontalin starting from easily available material, natural unsaturated aliphatic aicd, oleic acid. The synthesis is shown in scheme.

    A New Route for the Synthesis of (±)-Seudenol
    GAO Zhu-Lin, YIN Cai-Xia, LIU Fu-Chu
    2000, 21(S1):  496-496. 
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    Seudenol (3-methyl-2-cyclohexen-1-ol) is an aggregation pheromone isolated from female hindguts of the Douglas fir beetle, Dendroctonus pseudotsugae,by Vité[l]. Sivlerstein reported that the natural seudenol is racemic[2]. Racemic seudenols have been synthesized by various methods[3-5], almost all of which have used 3-methyl-2-cyclohexen-1-one (4) as precursor or intermediate, followed by reduction. Among reduction of enone (4), most systems studied to date have focused on selective reduction of α, β-unsaturated ketone to the corrsponding allylic alcohol. But most of the reduction required special and expensive reagent[3-5]. In this paper,a new convenient material route was reported to synthesize (±)-seudenol. The route is illustrated in the following scheme.

    A New Route for the Preparation of α,ω-Diacetylalkanes from Diacids and Enacid
    GAO Zhu-Lin, YIN Cai-Xia, LIU Fu-Chu
    2000, 21(S1):  497-497. 
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    Methyl ketones are important intermediates for the synthesis of methyl alkyl carbionols, annulation reagents, and cyclic compounds. There have been some methods to get methyl ketones such as alkylation of actone derivatives, hydration of olefins and acethylenes using mercury compounds. Compared with these methods, the palladium-catalyzed oxidation of α-olefins is more convenient and practical. Use of DMF as a solvent for the oxidation of α-olefins has been reported by Clement and Selwitz[1]. The method requires only a catalytic amount of PdCl2 and gives satisfactory yields, under mild conditions. This usefully sythetic method for preparation of methyl ketones has been applied extensively in syntheses of natural products such as steriods[2] and muscone[3]. Although a considerable number of studies have been carried out on palladium-catalyzed oxidation, they were done mostly with α-olefins. We paid attention to the usefulness of the reaction as a synthetic method for α,ω-diacetylalkanes from α,ω-olefins. The preparation of diolefins from diacids has not been reported in the previous literatures. Herein,we described our route for preparation of α,ω-diacetylalkanes.

    Synthesis and Properties of Axial Coordination Reaction of Unsymmetric Leucine Zinc(Ⅱ) Tetraphenylporphyrin with Pyrimidine
    NI Chun-Lin, XU Ji-Lin, ZENG Qing-Yu
    2000, 21(S1):  498-498. 
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    In recent years much work has been done on the syntheses and properties of axial coordination reaction of zinc tetraphenylporphyrins with nitrogenous donors in order to better understand the detailed molecuar mechanism of natural zincous enzymes. However,only a few studies have been reported in which the nitrogenous donors are bound to the amino acid metallotetraphenylporphyrins with unsymmetric structures. In this paper, a new unsymmetric leucine tetraphenylporphyrin, 5-(4-leucine butoxyphenyl)-10,15,20-triphenylporphyrin (H2[Leu-TPP]) and its Zn(Ⅱ) complex (Zn[Leu-TPP]) are synthesized. Their structures are characterized by elemental analysis, UV, IR, fluorescense spectra. The changes of the electronic absorption spectra of axial coordination reaction of Zn[Leu-TPP] with pyrimidine in chloroform are investigated Coordination number (n) and equilibrium constant (β) of the reaction are measured by visible spectra techniques. The changes of standard molar enthalpy (ΔrHm⊙) and molar entropy (ΔrSm⊙) of the reaction are calculated. The obtained data are listed in table 1.

    Synthesis, Crystal Structure and Characterization of 6-(p-tolyl)-6-H-Decachlorobenzo[cd]pyrene
    PENG Yin, XIE Su-Yuan, HUANG Rong-Bin, ZHENG Lan-Sun
    2000, 21(S1):  499-499. 
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    A new perchlorinated fused compound, 6-(p-tolyl)-6H-decachloro-benzo[cd]-pyrene 1, was synthesized with solvothermal reaction,a novel approach developed in our group. 1 is an interesting molecule for it is similar in structure to chlorinated fragment molecules of fullerenes[1]. Besides, its homologues such as 6-methyl-6H-benzo[cd]pyrenes, 6-methoxycarbonyl-6H-benzo[cd]pyrene and 6-mesyloxyl-6H-benzo[cd]pyrene[2] have been synthesized as parent hydrocarbons of benzo[cd]pyrenyl system, which were investigated for its NBMO properties[3].

    Synthesis and Bioactivities of Avermectin Bla Pyrethroid Derivatives
    LIAO Lian-An, FANG Hong-Yin, LI Zheng-Ming
    2000, 21(S1):  500-500. 
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    Avermectin and its derivatives were high activities and wide spectra insecticide and nematodes[1-3]. Ⅰn order to enhance its bioactivities and light stability, we prepared a series of Avermectin Bla pyrethroid derivatives(Ⅰ,Ⅱ),they showed high insecticidal activities in the preliminary bioassay.

    Synthesis of 1,4-Bis(Chloromethyl)-2-Methoxy-5-Phenoxy Benzene
    WANG Jian-Ying, HU Wen-Xiang, LONG Yong-Fu, LI Yin-Kui
    2000, 21(S1):  501-501. 
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    Much attention has been paid to Poly(p-Phenylene Vinylene) (PPV) because they are associated with good electro-optical characterization, especially electro-luminescence which first discovered by Burroughes in 1990[1]. 1,4-bis(chloromethyl) benzene is an important tool to synthesize PPV by dehydrochlorination. So the chloromethylation of substituted benzene becomes active. We once synthesized a series of dialkoxyl bischloromethyl benzene[2]. Unfortunately, short chain alkoxyl-substituted PPV has poor solubility, which limits its utility. There are little reports on aryloxy PPV up to now, while aryloxy-substituted PPV may has good mechanical properties.

    The Synthesis and Structure of Herbicidal Mononuclear Cobalt (Ⅱ) Sulfonylurea Complex CoL2 (L=Sulfometuron-methyl Anion)
    LI Bin, DING Yan-Bing, WEI Xiao-Li
    2000, 21(S1):  502-502. 
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    A number of sulfonylureas are commercialized ALS-inhibiting herbicides to control broad-spectrum weeds in various crops when applied at very low dosage (5-50 g/ha)[l]. But little sulfonylurea complex is investigated in the literature. Previously we reported the preparation and herbicidal activity of (Chlorsulfuron)2Cu(OAc)2[2]. Herein we report the preparation and structure study of the following novel sulfonylurea cobalt (Ⅱ) complex to study its herbicidal activity:

    The Synthesis of Tetracyclic Carboxylic Ester
    LI Bin, ZHANG Zong-Jian, LORI A. Spangler
    2000, 21(S1):  503-503. 
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    12H-Dibenzo[d,g] [1,3]dioxocin-6-carboxylic ester such as compound (Ⅰ) is a patented herbicide (US 4938790) with good pre- and postemergence activity on dicot weeds and sedges. Structure activity studies were initiated with the goal of discovering more synthetically accessible analogs with improved unit activity and crop-weed selectivity. As a part of above project the following novel compound (Ⅱ) was prepared to study the relationship between the structure and herbicidal activity:

    An Asymmetric Synthesis of Isoindolinones
    CHEN Ming-De, HUANG Li-Qiang, HUANG Pei-Qiang
    2000, 21(S1):  504-504. 
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    Recently, the results from this laboratory showed that the reductive alkylation of protected (S)-malimide could be achieved in a high regio- and diastereoselective manner. The substituted 2-pyrrolidinones thus formed are versatile chiral building blocks which can be used in the asymmetric synthesis of pyrrolidines[1,2],2-pyrrolidinones[3,4] and β-hydroxy-γ-amino acids[5,6]. As an extension of this work, and in combination with the current interest in the synthesis of isoindolin-1-ones, a study on the asymmetric reductive alkylation of phthalimide derived from (R)-phenylglycinol was undertaken.

    Synthesis and Biological Activity of Novel Aryl Sulfamonyl Ureas
    JIANG Lin, LI Zheng-Ming, JIA Qiang, WANG Su-Hua
    2000, 21(S1):  505-505. 
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    2-Substituted aryl sulfamonyl ureas are novel sulfonylurea compounds,in which the bridge was modified. For instance, 1-((o-cyclopropylcarbonyl)phenyl sulfamonyl)-3- (4',6'-dimeth-oxy-2-pyrimidinyl)urea is effective for the selective control of a variety of weed species in the presence of cereal crops and is especially useful for controlling broadleaf weeds and sedges[1]. For further structural study, nine aryl sulfamonyl ureas(3) were synthesized, including four 1-(o-substituted phenyl sulfamonyl)-3-(4'-substituted pyrimidin-2'-yl) ureas and five 1-(α-pyridinyl sulfamonyl)-3-(4'6'-disubstituted pyrimidin-2'-yl) ureas.

    Novel and Efficient Resolution of 1,1'-Bi-2-naphthol and Synthesis of Optically Pure Unsymmetrically Substituted Binaphthyls
    CHEN An-Qi, YE Jian-Jun, RUAN Yuan-Ping, ZHOU Cao-Hui
    2000, 21(S1):  506-506. 
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    Both enantiomers of 1, 1'-Bi-2-naphthol (BINOL) 1 are important chiral ligands and auxiliaries for a number of asymmetric transformations such as aldol condensations, alkylations, Diels-Alder reactions, Michael additions, epoxidations, etc. Optically pure 1 and their derivatives have also been used extensively in chiral recognition, chiral separation and construction of functionalised materials[1]. As a result the development of efficient and economic methods for the preparation of optically pure 1 has attracted much attention in recent years[2] and novel methods for the resolution of racemic 1 (Rac-1) continue to be developed.

    Oxidation of N,N-bis(Pyridymethyl)-2-aminoethanol (LOH) to the Corresponding Aldehyde Catalyzed by Copper(Ⅱ) Ion
    REN Yan-Ping, LONG La-Sheng
    2000, 21(S1):  507-507. 
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    On the effort to mimick the function of galactose oxidase (GO), only three copper(Ⅰ) complexes reported can catalyze efficiently the aerobic oxidation of primary and second alcohols to the corresponding aldehydes and ketons or 1,2-glycols by oxidative C-C coupling with concomitant formation of H2O2[1-3]. However, those complexes were catalytically inactive, when using copper(Ⅱ) instead of copper(Ⅰ). We report here an example of oxidation of N, N-bis(Pyridymethyl)-2-aminoethanol (LOH) to the corresponding aldehyde (L1O) catalytzed by copper(Ⅱ) ion.

    Synthesis of 3-Methyl-1H-Pyrazole-4-Carboxylic Ester Derivatives and Biological Activity
    ZHAO Wei-Guang, LI Zheng-Ming, LIAO Lian-An, YUAN Ping-Wei, WANG Wen-Yan
    2000, 21(S1):  508-508. 
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    Pyrazole derivatives have attracted much attention over the past two decades in pesticide chemistry due to their diverse biological activities. Some of them have been used as herbicides, insecticides, fungicides and acaricides. Herein, we report the synthesis and the fungicidal and antiviral activity of novel series of 1 -substituted-3-methyl-5-benzylamino (alkylthio, or alkylsulfonyl)-1 H-pyrazole-4-carboxylic esters.

    Synthesis and Biological Activity of α-Substituted 1,2,3-Thiadiazole-4-Acetic Acid Derivatives
    ZHAO Wei-Guang, LI Zheng-Ming, LIAO Lian-An
    2000, 21(S1):  509-509. 
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    Compounds containing 1,2,3-thiodiazole ring were reported to posses fungicidal1, herbicidal2 and growth regulation properties3. For example, N-phenyl-N'-1,2,3-thiadizazol-5-yl-urea (Thidiazuron, Dropp) has been used as a cotton defoliant4, herbicide and was also found to exhibit cytokinin-like activity in bioassay systems. The compound was more effective than Zeatin5 and 6-BA6. Because the synthesis of 1,2,3-thiodiazole ring is difficult,compounds containing 1,2,3-thiadiazole ring are relatively seldom reported. Herein, we report the synthesis of a novel series of α-substituted-1,2,3-thiadiazole-4-acetic acid derivatives.

    Synthesis the Analog of Strictosidine and Vincoside from Geniposide
    LIU Jian-Li, XU Shou-Ning, CHEN Hui, YANG Wen-Zhen
    2000, 21(S1):  510-510. 
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    Strictosidine (1), a well-known monoterpene indole alkaloid glycoside[1,2], is the precursor and building stone of nearly 2200 indole and related alkaloids and was first isolated by G. N. Smith from Rhazya[3]. It is constructed in vivo from secologanin (2) and tryptamine (3) by plant species[1], as well as in vitro in the presence of the enzyme strictosidine synthase, or under biomimetic conditions in aqueous solution at pH 4.5 (Scheme 1). In the coupling reaction, a new chiral center is formed with complete stereoselectivity in the presence of the enzyme, or together with vincoside (4) in a 1:1 ratio in the absence of the enzyme. Here we describe the preparation of the analog of strictosidine and vincoside from geniposide via the biomimetic conditions. 7 and 8 can be used as the starting material to synthesize other analogs of indole and related alkaloids.

    The Microwave Promoted Condensation of Aldehydes with Nitromethane
    LIU Jian-Li, PENG Dao-Bao
    2000, 21(S1):  511-511. 
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    The Knoevenagel condensation reaction of carbonyl-containing compounds with active methylenes is a classic general method for the preparation of valuable synthetic intermediates, while the use of nitroalkanes (Henry reaction) as the methylene component leads to nitroaldol products or nitroalkenes. A multitude of promoters have been developed for these reactions including acids, bases and ammonium salts. Recent reports concerning the ultrasound promoted the Henry reaction[1], led us to consider the application of microwave as another promoter. Repetition of the reaction with the same reagents and application of microwave led to a rapid, clean condensation. This result prompted us to investigate the scope of the method further. The microwave promoted reaction proved to be general (Table 1) for a variety of aromatic aldehydes under these conditions.

    A Convenient Synthesis of 2,5 (1H,3H)-Tetrahydroquinazolinedione Using Lanthanum Chloride as the Catalyst
    LU Jun, LI Wuan-Hua, BAI Yin-Juan, Ma Huai-Rang
    2000, 21(S1):  512-512. 
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    In the past decade,4-aryl-3,4-dihydropyrimidine derivatives have exhibited important pharmacological properties, e.g. as the integral backbones of several calcium channel blockers, antihypertensive agents, alpha-1a-antagonists, and neuropeptide Y (NPY) antagonists[1]. Several lead compounds were developed that are equal in potency and duration of antihypertensive activity to classical and second-generation dihydropyridine drugs[2].

    A New Approach in Enantioselective Catalytic with Bis(oxazoline) Ligand-Metal Complexes
    ZHENG Jian-Feng, JIN Li-Ren, HUANG Pei-Qiang
    2000, 21(S1):  513-513. 
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    In recent years, the research of enantioselective-catalyzed reaction and the catalyst has got great development. Of the various chiral catalysts, great attention was given to the C2-symmetry chiral bis(oxazoline)ligand-metal complexes for they could be easily synthesized and have shown good enantioselection in various catalytic processes, including cyclopropanation from dihalogenmethane[1] and diazoacetate[2].But no report has been found of enantioselective-catalyzed cyclopropanation from sulfonyl-carbanions and alkenes. The test of chiral cyclopropanation from sulfonylcarbanions with nickel bis(oxazolinyl)pyridine catalyst has been made in our lab, and alkylation of aldehydes with diethyl zinc in the presence of nickel or iron bis(oxazolinyl)pyridine was also tested (scheme 1). Some asymmetric effects were observed in these reactions.

    Synthesis of New Bis(oxazoline) Ligand-Metal Complexes
    JIN Li-Ren, ZHENG Jian-Feng, HUANG Pei-Qiang
    2000, 21(S1):  514-514. 
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    Great success has been achieved in the enantioselective-catalyzed reactions over the past few years. In the various catalyst, C2-symmetric chiral bis(oxazoline)ligand-metal complexes accepted great attention in recent years for they showed effective enantioselection in various catalytic reactions and were easy to be prepared from available optically active amine acid[1]. For the test of enantioselective-catalyzed cyclopropanation from sulfonyl-carbanions and alkenes, a series of new bis(oxazolinyl)pyridine complexes were synthesized. Nickel and iron was found as effective catalysts in the cyclopropanation from sulfonylcarbanions in previous research[2]. Some nickel or iron bis(oxazolinyl)pyridines were prepared(scheme 1). These complexes were characterized with MS, IR and so on.

    The Synthesis of Novel Sulfur-containing Chiral Macrocyclic Multidentate Ligands
    ZHAO Ying, XIE Ru-Gang
    2000, 21(S1):  515-515. 
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    The biomimetic chemistry has aroused widespread interest in the past two decades[l~4]. The molecular recognition property of chiral crown ether has attracted much attention, not only due to its wide applications to pharmaceutical science, catalysis, and separation technology but also because the inclusion process is considered an ideal model mimiching the enzyme-substrate interaction.

    Synthesis of Diethylaminoethyl Carboxylic Esters
    CHEN Ming-De, CHEN Jing, ZHOU Jin-Mei, LIAO Lian-An, LU Huo-Gui
    2000, 21(S1):  516-516. 
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    Dialkylaminoethyl carboxylic esters (1-5) with two biologically active moieties, carboxylic acid and dialkylaminoethanol were previously reported to show some biological activity in the presence of the coordinated effect of the two parts.

    A New Approach to the Asymmetric Synthesis of 3-Methylpyrrolidine Alkaloids
    ZHENG Xiao, WU Tian-Jun, HUANG Pei-Qiang
    2000, 21(S1):  517-517. 
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    3-Methylpyrrolidine alkaloids 1-5,isolated from the poison gland of several species of ants Leptothoracini (Myrmicinae), have been found to be pheromones and chemical weapons of them[1,2].Since these alkaloids are only available at nanogram scale, the development of asymmetric synthesis is of importance, in particular for evaluating their bioactivities.

    Biological Analysis
    Studies On the Development of a New Chiral 2-Pyrrolidinone Synthon
    ZHENG Xiao, LIU Liang-Xian, HUANG Pei-Qiang
    2000, 21(S1):  518-518. 
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    Previous results from this laboratory have showed that N,O-dibenzylated malimide 1 is a versatile intermediate for the asymmetric synthesis of pyrrolidines, 2-pyrrolidinons and β-hydroxy-γ-amino acids[1-4]. All the reactivities showed in synthon A have been exploited, in order to extend our studies on the (S)-malic acid-based synthetic methodology, we were interested to study the synthon B.To this end,sulfone 2 and 3,two the potential synthetic equivalent to synthon B, were prepared from malimide 1. Preliminary results showed that sulfone 2 indeed displayed the reactivity of synthon B.

    Synthetic Sciences
    Synthesis and Stereochemistry of Exogonic Acid
    ZHANG He-Sheng, FLETCHER Mary, KITCHING William
    2000, 21(S1):  519-519. 
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    Exogonic Acid (1) was isolated from the Brazilian tree, Ipomoea operculata. Dahlke and Graf first characterized (1) in 1964. Despite some subsequent work, it was not until 1992 that we determined the absolute stereochemistry of (1) by synthesis of enantiomers of (1) and application of enantioselective gas chromatographic technique. Here we wish to report our new seterocontrolled synthesis of (1) and its methyl ester.

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