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Table of Content

    24 May 2000, Volume 21 Issue 5
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    Articles
    Synthesis and Structure of a Three-dimensional Hydrogen-bonded Supramolecular Compound [H3cth] [Fe(CN)6]·3H2O
    GAO En-Qing, TANG Jin-Kui, LENG Xue-Bing, LIAO Dai-Zheng, JIANG Zong-Hui, YAN Shi-Ping
    2000, 21(5):  663-666. 
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    Ahydrogen-bonded supramolecular compound, [H3cth] [Fe(CN)6]. 3H2O, was synthesized from meso-5, 7, 7, 12, 14, 14-hexamethyl-1, 4, 8, 11-tetraazacyclotetradecane (cth) and K3 [Fe (CN )6]. The compound crystallizes in triclinic space group P1, with a=0. 93097 (9) nm, b=1. 05160(11) nm, c=1. 63847(17) nm, a=101. 077(2)°,β=90. 860(2)°, γ=111. 671 (2)°, V=1. 4564(3) nm3, Z=2, R=0.0415. The structure consists of neutral two-dimensional sheets assembled via hydrogen bonds be- tween the partially protonated macrocyclic tetraamine and the hexacyanoferrate(Ⅲ) ion, while the hydrogen bonds involving water molecules interlink the sheets to form a unique three-dimensional supramolecular architecture.
    The Preparation of Nano-titania/Wollastonite Composite
    YANG Shao-Feng, ZHAO Jing-Zhe, GUO Yu-Peng, WANG Zi-Chen, XUE Li-Jing, ZHAO Chun, ZHAO Mu-Yu
    2000, 21(5):  667-670. 
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    The composite of nano-titania/wollastonite were prepared by precipitating titania on the surface of wollastonite. Wollastonite powders must be pretreated in the process of coating. The composites were characterized by XRD, IR, SEM, TEMand XPSmethods. All the results revealed that the wollastonite was fully coated and the properties of the composite was similar to that of titania.
    Synthesis, Crystal Structure and Redox Properties of VO3+Hydrazone Complex with Alkoxide Ligand
    GAO Shan, LIU Shi-Xiong
    2000, 21(5):  671-674. 
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    The complex VO(L) (CH3O) (CH3OH) (H2L=salicylaldehyde benzoylhydrazone) was synthesized and characterized by elemental anlyasis, IR, UV, 1H NMR, cyclic voltammetry measurements and X-ray diffraction. The crystal belongs to monoclinic system, space group P21/c, with the crystal cell dimensions a=0. 8161(1) nm, b=1. 6946(2) nm, c=1. 2232(1) nm, β=104. 274(9)°, V=1. 6394(3) nm3, Mr=368. 26, Z=4. Two oxygen atoms and one nitrogen atom of the tridentate hydrazone ligand are coordinated to vanadium(V) atom, forming an equatorial plane. The vanadium atom approximates to a distorted octahedral coordination sphere. The redox potentials of the title complex in different solvents follow the order: CH2Cl2<CH3CN<DMF.
    Progress in Immobilization of Biological Materials by Sol-gel Method
    ZHANG Yu, CHEN Nian-You, ZHU Long-Gen
    2000, 21(5):  675-680. 
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    The advance in encapsulation of biological materials, such as proteins, enzymes, antigens(anti- gens(antibodies), cells, and microorganisms in SiO2 matrix by sol-gel process is reviewed. These biological materials encapsulated remain their biological activities and spectroscopic properties. They may be applied for making biocatalysts and biosensors.
    Synthesis, Characterization and Crystal Structure of [Cu(L-His) (Phen)]·2ClO4·H2O
    ZHOU Xiao-Hua, LE Xue-Yi, LI Ming-Hua
    2000, 21(5):  681-682. 
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    The crystal of [Cu(L-His) (Phen)].2ClO4.H2Owas synthesized and characterized by element analysis, molar conductivity, UV, IRand X-ray single crystal structure. The crystal belongs to monoclinic system, space group P21, with a=1. 2227(2) nm, b=0. 7145(14) nm, c=1. 4520(3) nm, β=109. 82 (3)° V=1. 1933(4) nm3, Z=2, F(000)=624, Dc=1.711 g/cm3, μ(Mo Ka) =12. 08 cm-1, R=0.0509, wR=0. 1392.
    Synthesis of ZSM-5 Zeolite Using γ-Aminopropyl Triethoxylsilane as Structure-directing Agents
    LI Xiao-Tian, SHAO Chang-Lu, QIU Shi-Lun, XIAO Feng-Shou
    2000, 21(5):  683-685. 
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    Zeolite ZSM-5 has been synthesized with the organosilicon compound γ-aminopropyl triethoxylsilane as structure-directing agent using the composition 10SiO2: Al2O3: 3-5Na2O: 0. 1-0.5R: 40-100H2O(molar ratios). First of all, γ-aminopropyl triethoxylsilane was quaternarized with bromoethane and ethyl alcohol. XRD, TG, DTAand SEMwere used to characterize the sample. The investigation proves that the organosilicon compound resides intact at the channel intersections, and that the silicon atom In this species is located in a framework position. Prehydrolysis of the organosilane precursor is necessary for zeolite formation.
    An Immunosensor of B Factor Based on Surface Plasmon Resonance
    SONG Da-Qian, MU Ying, ZHAO Xiao-Jun, ZHANG Han-Qi, SUN Jing, LIANG Feng, CAO Yan-Bo, JIN Qin-Han
    2000, 21(5):  686-689. 
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    Anovel optical immunosensor based on surface plasmon resonance(SPR) has been developed for identification of antigen. The sensor is designed on the basis of fixing angle of incidence and measuring the reflected intensities in the wavelength range of 200-800 nm. Molecular self-assembling in solution is used to form the sensing membrane on gold substrate. The kinetic processes of sensing monolayer formation were studied. Human Bfactor (Bf), an activator of complement C3, was detected in the concentration range from 0.02-5 μg/mL. Under the selected experimental conditions, the sensor has a good sensitivity, repeatability, reversibility and selectivity.
    Identification of Major Metabolites of Etofesalamide in Rabbits by Liquid Chromatography/Ion Trap Mass Spectrometry
    GU Jing-Kai, ZHONG Da-Fang, CHEN Xiao-Yan, ZHOU Hui, SHEN Jia-Cong, LIN Yang
    2000, 21(5):  690-693. 
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    The major metabolites of etofesalamide [N-(4-ethoxyphenyl)-2-hydroxyl-benzamide],a novel drug for acne therapy, in rabbits were described. Urine samples from 0 to 10 h were collected after single oral administration of 400 mg etofesalamide to four rabbits. The samples with or without hydrolysis by β-D-glucuronidase/sulphatase were purified by SPEcolumn (Sep-Pah C18) and then were analyzed with LC/MSn for potential metabolites. Etofesalamide and its five metabolites were identified in rabbit urine based on the reference substances and mass spectra. These included oxaphenamide [N-(p-hydrox- yphenylsalicyl)] and the conjugates of glucuronide and sulfate for etofesalamide and oxaphenamide, respectively.
    Direct Determination of Trace Impurity Yttrium in Titantium Oxide Powder by Fluorination Assisted ETV-ICP-AES Using Slurry Sampling
    PENG Tian-You, YAN Qin, HU Bin, JIANG Zu-Cheng
    2000, 21(5):  694-697. 
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    By using a polytetrafluorethylene(PTFE) emulsion as fluorinating reagent, a method for fluorinating assisted eletrothermal vaporization (ETV)/ICP-AESdirect determination of trace yttrium in TiO2 ceramic powder has been proposed; the various facts which would affect the vaporization process between the matrix and the analyte were studied ; the fluorinating vaporization behavior of the matrix and the analyte both in slurry and in solution were investigated. Based on pre-separation between the matrix and the analyte, the matrix effect was reduced. On the optimum experiment conditions, the detection limit of the present method is 0.26μg/L; and the RSDis 3.8 % (n=5, c=0.5 mg/L). This method has been applied to directly determinate trace yttrium in two kinds of TiO2 powder without any chemical pretreatment.
    Studies on the Theory and Applications of the Photoacoustic Phase of Solid Sample
    WU Rong-Hu, WAN Shou-Kang, SU Qing-De
    2000, 21(5):  698-701. 
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    Based on the R-Gtheory of the photoacoustic effect, a new formula on the PAphase was presented while the phase caused by non-radiative relaxation processes was considered. The phase is associated with the absorption coefficient(β), thermal diffusion length of sample(s), the delay time of relaxation(τ) and the ratio of the heat component(R) of rapid relaxation to that of slow one. The phase spectra of PrF3 and chlorophyll b were explained well by using of this formula. The phase of PrF3 is determined by the absorption coefficient for the f-f transition. The phase difference between the two bands of chlorophyll b is caused by the different heat component ratios of rapid relaxation to slow one.
    Covalent Immobilization of Trypsin on Glycidyl Methacrylate-Modified Cellulose Membrane as Enzyme Reactor
    JIANG Hong-Hai, ZOU Han-Fa, WANG Hai-Lin, NI Jian-Yi, ZHANG Qiang
    2000, 21(5):  702-706. 
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    The membrane of the activated glycidyl methacrylate (GMA)-modified cellulose was prepared and packed into a column piece by piece to make a microreactor by immobilization of trypsin. The microreactor based on the membrane medium showed the advantages of being cheaper, mechanically strong and chemically stable. The activity of immobilized trypsin towards N-benzoyl-L-arginine ethyl ester(BAEE) was 17800 U/g dry membrane, and was 52 % of that for free enzyme. Besides, the effects of pHvalue of buffer, temperature, ionic strength, organic modifier, and protein denaturants on the activity of immobilized trypsin were investigated in comparison to the free trypsin, and thermal stability also was found especially to be improved after immobilization. The activity of the immobilized trypsin showed no decay after continuously pumping BAEEthrough immobilized trypsin microreactor for 24 h at 40 ℃ and 0.5 mL/min. Finally, the cytochrome Cwas digested by microreactor and the products were analysed by MALDI-TOF-MS. The peptide mapping for a protein by combination of the immobilized enzyme membrane microreactor and MALDI-TOF-MShas been developed.
    The Study on the Element Transference Characteristics and Element Speciation in the Extract of Cyclocarya Paliurus(Batal.) Il jinskaja Leaves
    LI Lei, XIE Ming-Yong, SUN Zhen-Hua, WU Xi-Hong, SUN Da-Hai, WANG Xiao-Ru
    2000, 21(5):  707-709. 
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    The study on the element transference characteristics and element speciation in the extract of Cyclocarya paliurus(Batal.) Iljinskaja leaves was performed by FIA-ICP-AESon the basis of C-18 bonded silica gel column separation and microwave digestion/extraction for sample treatment. Higher transfer ratio could be obtained by artificial gastric acid or with microwave extraction method. The contents of inorganic species and organic species of the four elements in the microwave extract at the temperature of 100℃ are as follows. Zn: (4.46±0.13) μg/g and (8.16±0.15) μg/g; Mn: (35.7±1.1) μg/g and (91.2± 3.2μg/g); Mg: (156±9)μg/g and (513±11)μg/g; Fe: (3.28±0.19)μg/g and (8.43±1.15) μg/g, respectively.
    Spectroscopic and Electrochemical Studies on the Enzyme-catalyzed Reaction of PAP-H2O2-HRP
    ZHANG Shu-Sheng, JIAO Kui, LI Hui-Jing, CHEN Hong-Yuan
    2000, 21(5):  710-712. 
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    The pure product of p-aminophenol(PAP)-H2O2-horse peroxidase(HRP) of H2O2 oxidizing PAPcatalyzed by HRPwas prepared with chemical method. The enzyme-catalyzed reaction was investigated by electroanalytical chemistry, UV-Vis, IR,13C NMR, 1H NMR, mass spectrum and elemental analysis etc.. Under the selected enzyme-catalyzed reaction conditions, the oxidation product of PAPwith H2O2 catalyzed by HRPis 3,4-di-[(4-hydroxyphenyl)amino]-6-[(4-hydroxyphenyl)imino]-2,4-cyclo-hexadiene-1-one.
    Reaction of 1,2-Bis (tetramethylcyclopentadienyl )tetramethyldisilane with Hexacarbonyl Molybdenum
    DENG Xiao-Bin, XU Shan-Sheng, ZHOU Xiu-Zhong
    2000, 21(5):  713-716. 
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    1,2-Bis(tetramethylcylclopentadie reacted sequentially with n-BuLi and Mo(CO)6 to generate 1,1'-(tetramethyldisilandiyl ) bis [tetramethylcyclo-pentadienyltricarbony bdenum anion salt], (Me2SiMe2Si) [Me4CPMo(CO)3-Li+] (I). The further reaction of Iwith acetic acid, followed by halogenation with CCl4, NBSor I2 respectively yielded the corresponding molybdenum-halogen derivatives, (Me2SiMe2Si) [Me4CpMo(CO)3X]2, [X=Cl(1), Br(2), I (3)]. The reaction of compound Iwith MeIyielded the methylmolybdenum complex (Me2SiMe2Si ) [Me4CpMo (CO )3Me]2, (4). Strangely, the reaction of Idirectly with I2 gave the desilanyl product Me4CpMo(CO)3I(5). The molecular structures of compound 1-5 were characterized by elemental analyses, IRand 1H NMRspectra.
    Studies on the Synthesis and Propertics of Solid State Photochromism from 2, 2-Diarylnaphthopyrans
    KOU Xi-Yuan, WANG Yong-Mei, XU Li-Li, MENG Ji-Ben, WEN Zhen-Zhen
    2000, 21(5):  717-720. 
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    The title compounds were first designed and synthesized, the structures of all the compounds have been confirmed by 1H NMR, MSand elemental analysis. Combined with UV-Vis, the photochromism of these compounds was studied intensively. It was found that some of the 2, 2- diarylnaphthopyran compounds showed a good photochromism in the solid state, changing color quickly. Moreover, the relationship between the structure and photochromism properties was analyzed.
    Studies on Synthesis of Phosphonodipeptide Derivatives of exo-Bicyclo[2.2.1]heptane(or hept-5-ene)-2, 3-dicarboxylic Anhydride
    ZHOU Zheng-Hong, CHEN Ru-Yu
    2000, 21(5):  721-724. 
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    Cantharidin, the active constituent of Mylabris, has displayed significant antitumor activities in vitro and in vivo. The adverse effects on urinary and gastrointestinal tracts prevent it from being accepted by the clinic. In order to search for new antitumor drugs with a high activity and low toxicity, a series of phosphonodipeptide derivatives of exo-bicyclo[2.2.1]heptane (or hept-5-ene )-2, 3-dicarboxylic anhydride were synthesized by the condensation of the corresponding amino acid derivatives of exo-bicyclo[2. 2. 1] hept-5-ene-2, 3-dicarboxylic anhydride with a-aminoalkylphosphonate, and their structures were confrimed by 1H NMR, MSand elemental analysis.
    Synthesis and Properties of Extensively Conjugated Dianionic Tetrathiafulvalene Tetrathiolate-Bridged Bimetal Complexes
    WANG Jian-Hua, YANG Geng-Xin, CHI Xing-Bao, WANG Xiao-Gang
    2000, 21(5):  725-728. 
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    Four new extensively conjugated dianionic tetrathiafulvalene tetrathiolate-bridged bimetal complexes and two tetrathiafulvalene tetrathiolate multimetal oligomers were synthesized in this paper. UV-Vis spectra and cyclic-voltammograms of the four complexes were studied. The conductivity of these complexes and oligommers were given too.
    Synthetic Studies of HIV-active Didemnaketal A Analogue ──Synthesis of a C1-C7 Fragment
    JIA Yan-Xing, WANG Ping-Zhen, WU Bin, TU Yong-Qiang
    2000, 21(5):  729-730. 
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    AC1-C7 fragment of the HIV-active Didemnaketal Aanalogue was synthesized from (R)-pulegone through 12 steps. Two new chiral centers, C3, C4 were successfully constructed by the steric induction in this approach and the aldehyde was selectively reduced.
    Studies on the Mechanism of Adsorbents Contianing β-Cyclodextrin Acting on Bilirubin
    YUAN Zhi, WEI Bin, HANG De-Hua, SHI Lin-Qi, SONG Zheng-Ji, HE Bing-Lin
    2000, 21(5):  731-733. 
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    In this paper, we use glucose as the contrast to study the mechanism of β-Dextrine and fixed β-Dextrine acting on the bilirublin. The results show that the hydrogen bond is the main force between β-cyclodextrin and bilirubin. After the adsorption of bilirubin for 2 h, the adsorption capacity is over 90 %.
    Negative Photochromic Properties and Alkali-metal Cation Recognition of Crowned Spirobenzopyrans
    LIU Sheng-Hua, WU Cheng-Tai
    2000, 21(5):  734-736. 
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    The photochromism and alkali metal cation-induced coloration of indolinospiropyrans possessing monoaza-benzo-15-C-5 at 8-position were investigated by UV-Vis spectrometry. The results indicated that these compounds show negative photochromic properties differed from those of crowned spiropyran derivatives reported, and have an excellent recognition of alkali metal canon.
    Studies on the Packings with Guanido of Affinity Chromatography for the Separation of Urokinase
    CHANG Jian-Hua, GAO Jun-Ping, LIANG Feng, FENG Yue, DONG Yu-Sheng, SU Tian-Sheng, GUO Li-An
    2000, 21(5):  737-739. 
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    Five guanido packings of affinity chromatography for the separation of urokinase have been synthesized. The separation characteristics and the effect of matrix and ligands on them have been studied. The guanidine derivative is a fine ligand, the packings with ligand of arginine are much better than that with ligand of p-ABZ. The polyepoxypropyl methacrylate microsphere is a good matrix. The comprehensive function of packings with ligand of arginine and matrix of polyepoxypropyl methacrylate microsphere is more excellent than Sepharose-p-ABZ.
    Studies on the Reaction of 1,2,3-Trisubstituted Electron-deficient Cyclopropane Derivatives with Methanol
    CAO Wei-Guo, DING Wei-Yu, TONG Wei-Qi, LIU Xin, QIU Meng-Yao
    2000, 21(5):  740-742. 
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    In this paper, the reaction of 1, 2, 3-trisubstituted electron-deficient cyclopropane derivatives ets-1-benzoyl-2-p-substituted phenyl-6, 6-dimethyl-5, 7-dioxo-spiro-[2,5]-4, 8-octadiones with methanol was studied. The structures of the reaction products were confirmed as methyl　β-benzoyl-γ-methoxy-γ-p- substituted phenylbutyrates by means of IR, MS, microanalysis, 1H, 13C NMRspectroscopies and APTtechniques. The reaction mechanism for the formation of the product was also proposed.
    A Study of Mn-Se and Mn-O-Se Cluster Ions Using Mass-spectrometry
    CHEN Yun-Qing, XING Xiao-Peng, LIU Peng, ZENG Rong, GAO Zhen, ZHU Qi-He
    2000, 21(5):  743-746. 
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    Time-of-flight mass spectrometry was used to study Mn-Se and Mn-O-Se cluster ions produced by laser direct vaporization of solid samples. In Mn-Se binary cluster ions, (MuSe)n+ is the main composition of positive cluster ions, while [(MuSe)nSe]- is the main composition of negative cluster ions. When a mass-selected (MuSe)n+ was photolyzed, the photolysls produt ions have the same general composition (MuSe)m+. In Mn-O-Se ternary system, the main positive cluster ions produced are Mn-Obinary clusters, in which [(MnO)n]+ has a high intensity, while the negative cluster ions include Sen-,[SenO]-, [SenO3]- and [MnSen]-. It seems that the cluster ions were produced by the vaporization of solid sample and this conforms to a gas-phase aggregation mechanism.
    Kinetics and Mechanism of Oxidation of Ethylenediamine by Dihydroxydiperidatonickelate(Ⅳ) Complex Ion in Alkaline Medium
    LI Zhi-Ting, CHANG Qing, LI Bao-Wen, YANG Li-Ting, WANG An-Zhou
    2000, 21(5):  747-751. 
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    The kinetics of oxidation of ethylenediamine(en)by dihydroxydiperiodatonickelate(Ⅳ) complex 0.40) at 20-35℃. The reaction rate showed first-order dependence in oxidant and positive fractional order dependence in ethylenediamine. The pseudo first-order ([en]>> [DDN]) rate constant kobs increases with the increase of [OH-] and decreases with the increase of [IO4-], which implies that before the ratedetermining step there is a preequilibrium in which one of the periodate ligands of the oxidant is deprotonated and the other is dissociated, and dihydroxymonoperiodate (Ⅳ) complex (DMN ) is the reactive species. In addition, no salt effect and no free radical was observed, which indicates that an innersphere one-step two-electron transfer mechanism without free radical intermediate may be in operation. Based on the experimental results a mechanism involving a preequilibrium of an adduct formation between the [Ni(OH)2(HIO6)]2- and ethylenediamine has been proposed. The rate equation derived from the mechanism can be used to explain all the experimental results satisfactorily and the preequilibrium constants, rate constant of the rate-determining step together with the activation parameters were evaluated.
    Studies of Preparation and Stability of An/Fe2O3 Catalyst for CO Oxidation at Ambient Temperature and Moisture
    WANG Gui-Ying, YU Jia-You, LIAN Hong-Lei, LI Xue-Mei, JIA Ming-Jun, ZHANG Wen-Xiang, WU Tong-Hao, GE Yan-Dong
    2000, 21(5):  752-755. 
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    The catalytic performance of COoxidation at ambient temperature and moisture over An/Fe2O3 catalysts prepared by different methods was studied. It was found that the stability of the catalysts was greatly changed with the variation of the preparation methods, the kind of precipitant, calcination temperature, and An loading. The sample of 3%An/Fe2O3 prepared by adding HAuCl4 and Fe2(NO3)3 with K2CO3 or Na3CO3 as the precipitants, calcined at 250-350℃ in air for 3 h has the best stability and the best ability of resisting moisture, that is, the sample can maintain COcomplete conversion at 25℃ and ambient moisture for at least 430h. The XRDresults indicate that the stability is inversely proportional to the metallic gold and a-Fe2O3 particle sizes, and the chemical states of gold and iron were the main controlling factors of the stability of An/Fe2O3.
    Monte Carlo Simulation to the Effect of Potential Barriers on the Kinetics Behaviour of Reaction-limited Aggregation of Colloidal Particle Cluster
    WANG Hui, WANG Gui-Chang, PAN Yin-Ming, CAI Zun-Sheng, ZHAO Xue-Zhuang
    2000, 21(5):  756-761. 
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    The reaction-limited aggregation mechanism was simulated by Monte Carlo method for different potential barriers in three dimensions. The cluster size distribution can be called and agrees with the experiment result. The effect of potential barrier on the cluster-size dynamic scaling and distribution was studied on the levels of the micro-scope and meso-scope. In addition, the effects of potential barrier on the mean cluster size, the aggregation rate and the aggregation rate constant were studied by using the similar method also.
    A Molecular Dynamics Simulation of Infinite Dilute Diffusion Coefficients of Benzene and Naphthalene in Supercritical Carbon Dioxide
    ZHOU Jian, LU Xiao-Hua, WANG Yan-Ru, SHI Jun
    2000, 21(5):  762-765. 
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    The self-diffusion coefficients of supercritical carbon dioxide and the infinite dilute diffusion coefficients of benzene and naphthalene in supercritical carbon dioxide were investigated by MDsimulation with spherical Lennard-Jones model and site-site model respectively. It was shown that both spherical model and site-site model could be used to predict the self-diffusion coefficients of supercritical carbon dioxide well. The site-site model could be used to predict the self-diffusion coefficients more precisely than the spherical model does. An attempt has been made to compare the simulation results of infinite dilute diffusion coefficients of benzene and naphthalene in supercritical carbon dioxide between simple spherical model and site-site model. It was found that there was scarcely any difference between the prediction accuracies obtained from the two models. The site-site model could probe the detailed microstructure of supercritical systems more precisely.
    Studies on Electroless Deposition Catalyzed by Gold in Photographic Gelatin Layer with Positron Annihilation
    ZHANG Yi-Heng, GONG Zhu-Fang, ZHANG Guang-Xiang, JIANG Zhi-Quan XU Xu-Guo, YAN Tian-Tang, YU Shu-Qin, ZHUANG Si-Yong, PENG Bi-Xian
    2000, 21(5):  766-770. 
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    The mechanism of action of free volume holes in photographic gelatin on the electroless deposition process has been studied by Positron Annihilation Technology (PAT) in this paper. The results show that after complete activation, the average volume of the free volume holes in photographic decreas- es by about 0.011 nm3, which is equivalent to the volume of a gold atom. In the view of statistical average concept, every free volume hole is filled with a gold atom to catalyze the electroless copper deposition. Thus the imaging feature formed in the physical development is not filament, but spherical stacks. After electroless copper deposition is accomplished, the average volume of the free volume holes in photographic gelatin decreases by about 0.020 nm3, which is equivalent to the volume of three copper atom. Therefore the deposition of copper in isotropic and spherical form was not hindered by free volume holes in photographic gelatin.
    Theoretical Studies of Molecules with Nonlinear Optical Third-order Susceptibilities on Pull-push Multi-cycle Electro-optical Polymer Intermediates Including Thiophene Ring
    FU Wei, FENG Ji-Kang, REN Ai-Min, CUI Meng, JIN Hong-Wei, WANG Jiang-Hong, SHEN Yu-Quan
    2000, 21(5):  771-775. 
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    On the basis of INDO/SCImethod, using sum-over-states(SOS) formula, the nonlinear thirdorder optical susceptibilities γ(-ω;ω,-ω,ω) and γ(0; 0, 0, 0) of a series of novel pull-push electro- optical polymer intermediates have been calculated. The effects of the molecular backbone, donor substituents, accepted substituents, the number of thiophene-rings (namely the conjugated molecular length dependence) and the frequency of external field on γ have been studied. When the molecular chain is not too long, γ(0; 0, 0, 0) varies as the 2. 69 power of length.
    Application of Dynamical Lie Algebraic Method Combining Intermediate Picture to Energy Transfer in A+BC Collinear Collision
    YANG Ben-Hui, DING Shi-Liang, HAN Ke-Li
    2000, 21(5):  776-779. 
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    Under the semiclassical approximation, we apply the dynamical Lie algebraic method combining with intermediate picture to study energy transfer in the atom-anharmonic oscillatorcollinear collision. By using the first order approximation of group parameterswe solve the motion equation of group parameters and obtain the time evolution operator. As an example, the scattering system H2+He is considered. Our results are in good agreement with those obtained by the exact quantum mechanics calculations.
    Theoretical Studies on the Mechanism of the Cycloaddition Reaction Between Isothiocyanic Acid and Methylenimine
    WANG Yan, FU Xiao-Yuan, FANG De-Cai
    2000, 21(5):  780-784. 
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    The cycloaddition reactions of isothiocyanic acid and methylenimine forming four-or six-mem- bered ring products were studied theoretically. Bader type electron density topological analysis was also used to study the electronic structure of stationary points for the equimolar reaction. All the geometries of the stationary points on the reaction path have been optimized by RHF/6-31G*, MP2/6-31G* and B3LYP/6-31G* with energy gradient technique, and the single point energy calculations of the stationary points of equimolar reaction have been performed by MP4. 6-31G* method at MP2/6-31G* optimized geometries. All the transition states were characterized by vibration frequency analysis. The equimolar reaction is stepwise, proceeding via a zwitterionic intermediate; the second step is the rate controlling one and the activation barrier is 107.86 kJ/mol. In addition, the above intermediate can react further with another methylenlmine or isothiocyanic acid molecule respectively to form two six-membered ring(1: 2 and 2: 1) products. The 1: 2 reaction is concerted but asynchronous, the 2: 1 reaction is a synchronous concerted process. The barriers of these two reactions are 15. 88 and 21. 82 kJ/mol respectively and they are lower than that of reaction forming four-membered ring product. This is consistment with experimental fact.
    Doped ZnO Ceramics Characterized by Rietveld Whole Pattern Fitting
    NI Yu-Hua, MA Li-Dun, SHEN Xiao-Liang, SHI Guo-Shun
    2000, 21(5):  785-788. 
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    Doped ZnOceramics have complicated XRDdiffraction patterns. It is difficult to carry out qualitative, quantitative phase analysis and to determine the crystalline size and micro strain of them with traditional methods. Here we used Rietveld whole pattern fitting method to analyze them. The composition of spinel varied when the proportion of adulterant changes and it was detemined by whole pattern fitting. All the results were obtained simultaneously in fitting. Therefore the time for data processing was shorter than that the traditional methods need. And the results were more accurate than that obtained by traditional method. It was found that ceramics consist mainly of bigger ZnOgrains (the lattice parameters of them are close to those in pure ZnOso they are not doped with other metals), and intergranular high dispersive Bi2O3 and spinel grains.
    Synthesis of Perchlorinated Polycyclic Aromatic Hydrocarbon by Laser Ablation
    ZHOU Yi-Nan, XIE Su-Yuan, CHEN Hong, HUANG Rong-Bin, ZHENG Lan-Sun
    2000, 21(5):  789-790. 
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    By laser ablating graphite in the vapor of tetrachloromethane, a series of perchlorinated polycyclic aromatic hydrocarbons were synthesized. Among them, hexachlorobenzene (C6Cl6), octachloronaphthalene (C10 Cl8), octachloroacenaphthylene (C12 Cl8), decachloroanthracene (C14 Cl10), decachlorophenanthrene (C14 Cl10 ), decachloropyrene (C16 Cl10 ), decachlorofluoranthene (C16Cl10 ), C18 Cl10, C20Cl10, C22Cl12 and C24Cl12 were identified by HPLC-UV-MS. The results demonstrate the potential of the reaction for synthesizing the compounds with special structures.
    Thermochemical Study on the Reaction of Lanthanum Nitrate with Alanine
    LI Qiang-Guo, QU Song-Sheng, ZHOU Chuang-Pei, LIU Yi
    2000, 21(5):  791-793. 
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    The standard molar reaction enthalpy of the solid-solid coordination reaction, La(NO3)3. 6H2O (s) + 4Ala(s) (Ala is Alanine) =La(NO3)3· (Ala)4·H2O(s) + 5H2O(1), has been studied by the classical solution calorimetry. The molar dissolution enthalpies of the reactants and the products in2 mol/L HCl of this solid-solid coordination reaction have been measured by using an isoperibol calorimeter. From the results and other auxiliary quantities, the standard molar formation enthalpies of [La(NO3 )3· (Ala)4· H2O, s, 298.15 K] have been determined to be[La(NO3)3·(Ala)4· H2O, s, 298. 15 K]= -3864.247 kJ/mol.
    Analysis of Conductive Process of the Solid Electrolyte Based on Urea and Thiourea
    ZHAO Di-Shun, ZHANG Xing-Chen, ZHOU Qing-Ze, LI Hui-Yong, ZHANG Yue, XIONG Pei-Wen
    2000, 21(5):  794-796. 
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    The conductivity of the solid electrolyte based on urea and thiourea has reached 6.84 ×10-3S.cm-1 at room temperature. Analysing the conductive process of this electrolyte we found that thiourea changes into ammonium thiocyanate at a high temperature, which ionizes into ions, and can conduct the current. We obtained a red color substance through electrolysing the SPE. Analysing it with IR, UVand FAB, we confirmed that it is a polymer with a structure (SCN)n. It is proved that the aninon is SCN-. When weadded HCl into the acetone solution of the SPE, it was found that white precipitation material appeared in the solution, which was identified as NH4Cl, so the canon is NH4+.
    Studies on the Diameter of Micelle of Aqueous Polyurethane Anionomers Dispersion
    LIU Jian-Hong, REN Xiang-Zhong, LIU Dong, TIAN De-Yu, TONG Yi, LI Wei
    2000, 21(5):  797-800. 
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    In this paper, the aqueous polyurethane anionomer dispersion (APUAD) was synthesized and the diameter of micelle of APUADwas measured by dynamic light scattering method. The results showed that the diameter of the micelle greatly depends on the number of the water-soluble group on the polyurethane, the flexibility and the hydrophobic/hydrophilic ratio of the main chain of the polyurethane. The phase separation was observed in the micelle by TEM.
    Crystallization Behavior of Polyethylene Glycol Terephthalate/Polyethylene Glycol Intercalated Block Copolymers
    JIN Xiao-Fang, WANG Ping, YI Guo-Zhen, YANG Yu, ZHANG Guo-Yao
    2000, 21(5):  801-804. 
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    Polyethylene glycol terephthalate/polyethylene glycol(poly tetramethylene glycol)/Montmorillonite intercalated block copolymers, PET/PEG (PTMG)/MMT, were synthesized with different mass fractions and molecular weights of PEG. The dispersion of MMTin copolymer matrixes and the influence of PEGor PTMGon the crystallization behavior of PET/MMTwere studied. It was revealed that MMTlayers were dispersed at nano-scale in PET/PEGmatrixes. PEGor PTMGsegments improved the flexibility of PETmolecular chain, resulting in the decrease of the cold crystallization temperature of the intercalated block copolymers and the increase of the melt crystallization temperature. It meant that the crystallization rate of PET/PEG/MMTwas faster than that of PET/MMT. Among the copolymers we synthesized, PEG-2000 (mass fraction:6%) had the best promoting effect on the crystallization rate of PET/MMT.
    Preparation and Photoconductivity Study of the C60/MMA Copolymers
    WANG Chang-Chun, TAO Zheng-Hong, HU Jian-Hua, FU Shou-Kuan
    2000, 21(5):  805-808. 
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    Aseries of C60/MMAcopolymers were synthesized by free radical polymerization. The experimental results showed that the polymerization conversion rate went up along with Increasing the amount of initiator dramatically. Meanwhile, the C60/MMAcopolymers were characterized by the techniques of elemental analysis, GPCand DSC. In this paper, the photoconductivity of the C60/MMAcopolymers was al- so studied, and the influence parameters, such as exposure intensity, thickness of interface layer, of the photoconductivity have been discussed, separately. From the experimental results, it can be conclude that C60/MMAcopolymers will become a candidate of photoelectric materials.
    The Properties and Preparation of Crosslinked Chitosan Films
    ZHENG Hua, DU Yu-Min, YU Jia-Hui, XIAO Ling
    2000, 21(5):  809-812. 
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    The crosslinked chitosan films were prepared with epichlorohydrin as a crosslinking agent, and characterized by FTIR, X-ray diffraction and SEM. Their mechanical properties were measured. The structure analysis indicated that at low temperature, the crosslinking reaction only occurred between -NH2 group of chitosan and epichlorohydrin. When the temperature was above 40 ℃, -OHgroup of chitosan reacted with epichlorohydrin. The results from SEMand measurement of mechanical properties showed that the tensile strength of the crosslinked films was considerably improved, and the rate of degradation of crosslinked films by lysozyme was reduced. The new crosslinked chitosan films are expected to be used as controllable degradation biomaterials.
    Comparison of the Effects of Acetoxy and Hydroxy Groups on the Water Uptake into the Cured Epoxy Resin
    LI Shan-Jun, ZHANG Shu-Yong, LUO Xiao-Wen, DING Yi-Fu, ZHOU Wei-Fang
    2000, 21(5):  813-815. 
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    Acomparison of the effects of acetoxy and hydroxy groups on the water uptake into the cured epoxy resin was made using the gravimetric method, DSCand corrosion test. The experimental results show that the replacing of the hydroxy groups with acetoxy groups in the resin causes less water uptake, but increases the diffusibility of water in the resin. For example, at 30℃, the equilibrium water sorption of the o-cresol novolac epoxy resin cured with phenol novolac acetate resin (EPA ) is 0.84% (mass fraction), while the epoxy resin cured with phenol novolac resin(EP) is 1. 97 %; the activation energies for diffusion of water in EPAand EPare 40 and 48 kJ. mol-1 respectively. The effects may be mainly due to the hydrophobic methyl group of the acetoxy groups. The methyl group prevents the uptake of water, but makes the acetoxy group more flexible, which causes water diffusion less difficult. Moreover, the results show that the unique structure of the interphase of the EPAcoating/Al substrate even causes further less water uptake, and improves the effectiveness of corrosion protection for the coating accordingly.
    Preparation, Characterization and Photoconductivity of C60 Grafted Poly(N-vinyl carbazole)
    LI Lang, TAO Zheng-Hong, WANG Chang-Chun, YANG Wu-Li, FU Shou-Kuan
    2000, 21(5):  816-818. 
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    The C60 grafted poly(N-vinyl carbazole) (PVK) polymer(CGP) was prepared by simple radical polymerization initiated by BPOat 90℃.The products were characterized by UV-Vis, FTIR, GPCand fluorescence and it was proven that C60 was grafted covalently to the PVK. The C60 moiety in the product was about 1. 2% (mass fraction). The photoconductlvity study revealed that the photoconductivity of PVKwas improved obviously through grafting C60.The half time of light decaying (t1/2) of CGPreached 0. 35 s.
    Synthesis and Conformation of Poly(L-γ-Chloroethyl glutamate)
    LIN Heng, SHAO Zheng-Zhong, ZHOU Ping, GAO Qin-Wei, YU Tong-Yin
    2000, 21(5):  819-821. 
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    Triphosgene was used to react with γ-chloroethyl glutamate, which was synthesized from 2-ethylene chlorohydrin and L-glutamic acid, to give γ-chloroethyl glutamate N-carboxyan.hydride (NCA). Thus, poly(γ-chloroethyl glutamate), a new poly (amino acid) with reactive chloride, was obtained from the NCAby using triethylamine as the initiator which can lead to intrinsic viscosity of polypeptide, [η], over 50 mL/g. NCAand polymer were characterized by IR, 1H NMRand 13C NMR. Oligomer of γ-chloroethyl glutamate was also obtained while NCAwas initiated by moisture in air. The conforma- tions of oligomer and polymer of γ-chloroethyl glutamate were observed by IRand CDspectroscopy. The results suggested that the conformation of oligomer mainly be β-sheet, while the polymer be α-helix.
    Synthesis of Poly-[2.5-bis(4'-methoxybenzoyloxy)benzyl acrylate] and Poly-[2, 5-bis(4' -methoxybenzoyloxy)benzyl methacrylate]
    MI Qi-Ding, WAN Xin-Hua, ZHOU Qi-Feng
    2000, 21(5):  822-824. 
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    Two monomers of 2, 5-bis (4'-methoxybenzoyloxy) benzyl acrylate and 2, 5-bis (4'-methoxy- benzoyloxy)benzyl methacrylate and their corresponding polymers were successfully synthesized. The mesomorphic behavior of both polymers was examined using differential scanning calorimetry(DSC) and polarized optical microscopy(POM). It was found that both polymers are noncrystalline with a glass transition temperature of 73. 1℃ for poly-[2, 5-bis(4'-methoxybenzoyloxyben acrylate] and 120. 3℃ for poly-[2' 5-bis (4'-methoxybenzoyloxy ) benzyl methacrylate], above which liquid crystalline state is formed. The clearing temperature of the former is 178. 3℃ and that of the latter is 172. 8 ℃.
    An Investigation of the Property of the Complex Carrier for Separating Fructose from Fructose-glucose Syrup
    TONG Yi, SHI Li-Xin, LI Wei, ZHAO Xue-Song, ZHOU Hui
    2000, 21(5):  825-827. 
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    The separation of fructose from fructose-glucose syrup by using macroporous dihydroxyborylated polystyrene resin(MDPR) has been amplified to get fructose syrup with a high purity. The absorbing and eluting conditions has been optimized, i.e., the ratio of length to diameter of the column was reduced from 175: 1 to 40: 1, which was applied to CSEPchromatography separation system. By applying this system, the purity of the final separated fructose was 95% with a concentration of 35%, and the recovery ratio reached 90%. This kind of resin showed promise in industrial application.
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