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Table of Content

    24 September 1998, Volume 19 Issue 9
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    Articles
    The Ring Like Structures in Gallostone and Its Formations in a Mimetic System in Vitro
    HUI Jian-Bin, LIU Hui-Zhou, XU Yi-Zhuang, BIAN Jiang, WU Jin-Guang
    1998, 19(9):  1359-1362. 
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    In a chemical mimetic system in vitro, the formation process of gallstone with ring-like structures were extensively investigated. It was observed that ring-like structures were formed and the patterns with characteristics of self-organization were also produced in the mimetic system. Both of the precipitates and fractals formed in the mimetic system were arranged in a regular ring-like way. The experimental results also showed that there are strong interactions and cooperation behavior between cations. So we speculated that all of these structures might follow a “Concentric Rule” when ring-like patterns were formed. The “Concentric Rule” is that: In an open system, which can exchange energy and materials with environment, there will be order structures automatically and all the ring-like structures will share the same center of circle and all patterns will grow around this center although each ring-like structure has its own radius. The growth region of each ring-like pattern will be controlled by their own radius. According to this rule, we can explain and understand almost all the phenomena occured in our experiments.
    Studies on Interaction of Copper Complexes of Cu(phen) 22+ and Cu(bpy) 22+ with 6-Mercaptopurine and Adenine
    ZHANG Rong-Li, ZHU Jun-Jie, ZHAO Guang-Chao, CHEN Hong-Yuan
    1998, 19(9):  1363-1368. 
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    In this paper, the interaction of complexes Cu(phen) 22+ and Cu(bpy) 22+ with 6-mercaptopurine (6-MP) and adenine were studied by fluorescence, UV-Vis spectroelectrochemical, and spectroelectrochemical methods. Fluorescence and electrochemical results indicated that the complex ratios of copper complexes with 6-MPand adenine are 1:1, and the complex constants of Cu(phen) 22+ and Cu(bpy) 22+ with 6-MPare 2.23×104 L/mol and 6.11 ×104 L/mol, with adenine being 1.91×104 L/mol and 5.45×104 L/mol respectively. Spectroelectrochemical behavior of the copper complexes changed obviously in the presence of 6-MP.These results indicated that there are strong interactions of copper complexes with 6-MP.
    Electrochemical Studies on the Intermetallic Interaction in Polynuclear Complexes Preparation, Structure and Electrochemical Properties of Terpyridine Complexes
    YIN Ye-Gao, CHEUNG Kung-Kai, Huang-Yong-De
    1998, 19(9):  1369-1374. 
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    The syntheses, structures and electrochemistry of two Co(Ⅱ) complexes Co(Ⅱ)(L1)2 (ClO4)2·4CH3CN(1) and Co(Ⅱ)(L2)2 (ClO4)2·H2O(2) prepared from ligands L1(4'-phenyl-2,2':6',2″-terpyridine) and L2(4'-ferrocenyl-2,2':6',2″-terpyridine) are reported in this paper. The electrochemical investigation shows that the oxidation potential of ferrocene unit in 2 has a 0.14 V positive-shift from that of ferrocenyl group in L2 for the introduction of Co 2+ and, in the meantime, that the redox potential of cobalt centre in complex 2 has a 0.06 Vnegative-shift from that of cobalt centre in complex 1. This observation strongly suggests that in complex 2, there is an intermetallic interaction between Co(Ⅱ) and Fe(Ⅱ) conducted by the molecular fragment.
    Microcavity of Strong Fluorescence Terbium Complex LB Film
    HUANG Yan-Yi, YU An-Chi, HUANG Chun-Hui, ZHAO Xin-Sheng, GAN Liang-Bing, LIN Yong, ZHANG Bei
    1998, 19(9):  1375-1377. 
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    Anew λ /2 resonant microcavity in which a terbium complex is used as emitting material and silver mirrors as reflectors has been fabricated successfully by LBtechnique. Two most important microcavity effects, fluorescence intensity enhancement and life time shortening, have been observed simultaneously for the first time from a series of resonant microcavities.
    Low Temperature Hydrothermal Synthesis and Characterization of Polycrystalline La2M2O7 (M=Ti, Zr) Powders
    CHEN Dai-Rong, JIAO Xiu-Ling, XU Ru-Ren
    1998, 19(9):  1378-1380. 
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    La2M2O7(M=Ti, Zr)powders have been hydrothermally synthesized at lower temperature from the double oxides xerogels by using KOHas mineralizer. The effects of some factors such as KOHconcentration, reaction temperature and time are investigated. Further details are given through XRD, TEM, IRand other techniques. The moderate conditions give the excellent ceramics powders: the resulting particles with a single mode of size distribution present a low agglomeration.
    Synthesis and Characterization for C70 (OsO4Py2)3 Complex
    YANG Sen-Gen, WU Zhen-Yi, CHENG Da-Dian, ZHAN Meng-Xiong, ZHENG Lan-Sun
    1998, 19(9):  1381-1382. 
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    The fullerene complex, C70 (OsO4Py2)3, was prepared by the reaction of C70 with OsO4 and Py in methylbenzene at room temperature. The new complex was characterized by elemental analysis, IRand electronic spectra. The complex structure was supposed.
    A New Fluorescence Optic fiber Sensor for Metronidazole
    TANG Jiang-Hong, HE Ping, LIU Wan-Hui, SHEN Guo-Li, YU Ru-Qin
    1998, 19(9):  1383-1387. 
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    Afluorophore of 1,4-bis(1,3-benzoxazol-2-yl)benzene(BBOB) was selected as sensing molecule for constructing a new metronidazole optic-fiber sensor. The sensing performence is based on the fluorescence quenching of the plasticized PVCoptode membrane trapped with BBOBby metronidazole. The quenching mechanism includes a primary inner filter effect and the formation of a charge-transfer complex between BBOBand metronidazole extracted from aqueous phase into membrane phase. In the range of 4.00×10-6～1.00×10-4 mol/L, the sensor responds linearly to metronidazole with a detection limit of 1.0×10-6 mol/Lmetronidazole. Agood reversibility and a rapid response within 30s were obtained. The relative standard deviation of repeating measurements of 1.00×10-4 mol/Lmetronidazole is 0.82%( n =10). The sensor shows good selectivity over the common inorganic ions and pharmaceutical species and therefore can be used for the direct determination of metronidazole in commercial preparations, the results were in agreement with those obtained by pharmacopoeia method.
    Studies on Character of Adsorption and Recognition of Etharidine Template Polymer
    ZHOU Jie, HE Xi-Wen, YANG Wan-Long, SHI Hui-Ming
    1998, 19(9):  1388-1392. 
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    By using etharidine as the template molecules, methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the crosslinking monomer, a kind of new molecular template polymer which had enzyme or recepter analogous binding sites and could highly specifically adsorb etharidine was prepared by molecular template technology. Its adsorption property and selective recognition for etharidine and other substrates were studied. The results showed etharidine template polymer had higher adsorption character, high selectivity and recognition ability, as compared with non-template polymer whose chemical composition was the same as it. And ionic interaction and hydrogen bonds played an important role in the selective adsorption of template polymer.
    Application in the Damage of DNA by Electrochemical DNA Sensor
    SUN Xing-Yan, XU Chun, LIU Sheng-Hui, HE Pin-Gang, FANG Yu-Zhi
    1998, 19(9):  1393-1396. 
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    Mutation and damage in DNAby interaction, UV-irralation, nitrite action and ultrasonication were studied by means of voltammetry using a graphite electrode covalently immobilied with ssDNA-1. Daunomycin was used as a hybidization indicator. When the complementary ssDNA-2 in solution was damaged by phsical or chemical agents, the hybridization of ssDNA-1 and ssDNA-2 was changed. All the results in voltammogram indicated that intercalator can't destroy the double-helical structure of DNA, while UV-irralation and nitrite action can make the permanent damage. Ultrasonication can reduce polymerization in DNAand the hybridization time was shortened. This may provide a new method for clinical medicine study.
    Direct Enantiomeric Resolution of Racemic μ-FcC-CHCoW-(CO)5(CpCOOC2H5) Using Amylopectin Tris(phenylcarbamate) Chiral Stationary by HPLC
    WU Shu-Lin, ZHOU Zhi-Qiang, DING Er-Run, YIN Yuan-Qi
    1998, 19(9):  1397-1400. 
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    Amylopectin tris(phenylcarbamate) was synthesized and used as the chiral stationary phase upon adsorbed over silica gel. For this purpose, amylopectin was allowed to react with an excess of phenylisocyanate in pyridine for 48 h. The carbamate was dissolved and adsorbed on silica gel which had been treated with 3-aminopropyltriethoxysilane. The weight ratio of the carbamate to the silica gel was 0.45:2.55. The racemic μ-FcC-CHCoW(CO)5 (CpCOOC2H5) prepared from μ-FcC-CHCo2.(CO)6 and (C2H5OOCCp)W(CO)3Na was resolved on this chiral stationary phase. Separation was carried out at room temperature, and methanol was used as the eluent at a flow rate of 0.5 mL/min.
    Studies on a Fiber Optical Sensor for Sulfur Dioxide with a High Sensitivity
    XU Han-Ying, WANG Ke-Min, WANG Da-Ning, LI Qing-Cai
    1998, 19(9):  1401-1404. 
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    The present paper decribes a fiber optical sensor with a high sensitivity to determine sulfur dioxide. In order to improve the sensitivity, a non-steady state approach was adopted and the sensor response was recorded after the reaction being proceeded for 1 or 2 min. Effects of NaHSO3 concentration and thickness of sensing layer of liquid on the sensor response were investigated. Agood linearity in a wide concentration range of sulfur dioxide, 3.1×10-7 ～7.8×10-5 mol/L, was displayed. The detection limit was 1.6×10-7 mol/L. Using the sensor to determine the amounts of SO2 in the wine, the results were in good agreement with the results obtained by the standard method.
    Spectroelectrochemical Study of Hemoglobin at Bare Silver Electrodes
    YE Bao-Xian, FANG Cheng, ZHOU Xing-Yao
    1998, 19(9):  1405-1407. 
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    This paper reports our recent study for the spectroelectrochemistry of hemoglobin at bare silver electrodes using a self made long optical path UV/Visible thin layer spectroelectrochemical cell. By this cell, the electron transfer number( n =1.04), the adsorbance ( Γ = 8.95×10-14 mol/mm2) and the formal redox potential( E0'=0.14 V) of hemoglobin at bare silver electrodes were studied.
    Determination of 5-HT with Nafion Modified Electrode
    LIU Ying, ZOU Ming-Zhu
    1998, 19(9):  1408-1410. 
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    Anew method for determination of 5-HTwith Nafion modified electrode is described in this paper. The ion-exhcange selectivity coefficient, the apparent diffusion coefficient and the distribution cofficient are calculated based on data from several experiments, which are 1.49×103, 1.29×10-10 (cm2/s), 1.81×104, respectively. Meanwhile, an example is also given by analysis of 5-HT in rabbit brain, the result is satisfactory.
    Studies on Semisynthesis and Antimicrobial Activity of 7β-Heterocyclicamido Cephalosporins
    ZHANG Zi-Yi, LIANG Yu-Xiang, HAO Lan, GUAN Zuo-Wu
    1998, 19(9):  1411-1415. 
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    Nine new 7 β-(1-aryl-5-methyl-1H-1,2,3-triazolyl-4-formamido)cephalosporins 3a-3j were synthesized by acylation of 7 β-amino group of 7-ACA, 7-ADCAand 7-ACT, with 1-aryl-5 methyl-1H-1,2,3-triazolyl-4 formyl chloride 2a-2c. Two new 7 β-(1,2,3-benzotriazolyl-1-acetamido) cephalosporins 6a 6b and two new 7 β-(5-methyl isoxazolyl-3-formamido) cephalosporins 9a-9b were obtained with the same acid choride. Isolation and purification of the new compounds were fulfilled with Sephadex LH-20 column chromatography and centrifugal TLCtechnique. The structure of the compounds were confirmed by elementary analysis, IR, 1HNMRand FAB MS, some of them showed a significant antibacterial activity.
    Chiral Schiff Base Ti(OR)4 Complexes Catalyzed Asymmetric Trimethylsilylcyanation of Aldehydes
    FENG Xiao-Ming, GONG Liu-Zhu, HU Wen-Hao, LI Zhi, PAN Wei-Dong, MI Ai-Qiao, JIANG Yao-Zhong
    1998, 19(9):  1416-1421. 
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    Aseries of new chiral catalysts of Salen-Ti(OR)4 complexes were synthesized, which were found to be efficient catalysts for the enantioselective silylcyanation of aldehydes. The enantioselectivities of 22.4%-87.1% were obtained by using chiral Salen Ti(OR)4 complexes as catalyst. The reaction mechanism was proposed and justified by experiments.
    Studies on LB Film and Fluorescence Properties of Cholesteric Liquid Crystalline Diaza Crown Ether and Its Complex with Eu(Ⅲ)
    LI Long-Zhang, ZHU Jia-Li, ZHAO Wei, XIE Ming-Gui, JIANG Qing, WANG Ling-Xuan, LI Tian-Kai
    1998, 19(9):  1422-1425. 
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    LBfilm and flourescence properties of the crown ether(1)( N,N'-bi(cholest-5-en-3β-oxocarbonylmethyl)-1,10-diaza-4,7,13,16-tetra-oxocycloctadecane), its complex with Eu 3+ (2) and the mixture of 2 and benzoic acid(3) have been studied respectively. All of 1, 2 and 3 can from perfect monolayer on the subphase of water and only the monomolecular area of 1 is changeable with subphase pH. The monolayers of 1, 2 and 3 can be transfered to quartz glass substrate fo form LBfilm respectively. Among the three LBfilms, 2 and 3 are Xtype and their transfering ratio are 06 and 10 respectively. Fluorescence exciting wavelength of 2 in solution is wider than that of Eu 3+. The fluorescence intensity of 2 of LBfilm is much greater than that in solution. Addition of benzoic acid to 2 also increases the fluorescence intensity of the LBfilm, because benzoic acid makes the LBfilm structure better. These LBfilms, even containing benzoic acid, are not very stable.
    Synthesis and Crystal Structure of Diastereomeric Racemates 2-Amino-3-cyano-1-phenyl-4-(3,4-methylenedioxy phenyl)-2-cyclopenten-1-ol
    SHI Da-Qing, LU Zai-Sheng, DAI Gui-Yuan
    1998, 19(9):  1426-1430. 
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    The diastereomeric racemates ( 1S, 4R; 1R, 4S ) and ( 1S, 4S; 1R, 4R )2-amino-3-cyano-1-phenyl-4 (3,4-methylenedioxyphenyl)-2-cyclopentene-1-ols were synthesized by the catalysis of low-valent titanium reagent(TiCl4-Zn) with 3-oxo-1-(3',4'-methylenedioxyphenyl)-3-phenylpropyl-1-propanedinitrile. Their relative configurations were determined by X-ray analysis.
    A New Flavonecrown Ether and Its Complexation with Alkali and Alkaline Earth Metal Cations
    LI Hua-Ping, WANG Peng-Fei, WU Shi-Kang
    1998, 19(9):  1431-1435. 
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    Anew kind of flouroionophore flavonecrown ether(FC)[4'-(dimethylamino)-3,6-(tetraethylene)-flavone was synthesized and characterized. The photophysical changes upon complexation with alkali and alkaline earth metal cations can be described in terms of enchancement of the cation-induced intramolecular charge transfer in the flavone owing to the direct interaction between the bound cations and the carbonyl group of the flavone. The magnitude of the photophysical changes is controlled by the size of crown and charge density of the bound cations. Based on the determination of the stability constants, the selectivity of flavonecrown ether is different from the regular crown ether. The results obtained were discussed preliminarily.
    Synthesis and Structural Studies of Tetramethyldisiloxanyl Dicyclopentadienyl Lanthanide Chlorides
    SONG Fu-Quan, MU Ping, BI Lan-Rong, WANG Zhao-Yu
    1998, 19(9):  1436-1439. 
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    There reactions of anhydrous NdCl3 and/or SmCl3 with Na2(C5H4SiMe2)2Oin 1:1 molar ratio in THFafforded the title compounds O(Me2SiC5H4)2Ln( μ-Cl)(THF)2 Ln=Nd(1), Sm(2). Compounds 1 and 2 were characterized by elemental analysis. X-ray structural analysis revealed that 1 and 2 are dimeric compounds bridged by two chloro atoms.
    Molecular Recognition Study on Supramolecular System(ⅩⅦ) Inclusion Complexation of Some β-Cyclodextrin Derivatives Containing Organo selenium with Aliphatic Alcohols
    LIU Yu, LI Bin, LI Zi-Yun, LI Jing
    1998, 19(9):  1440-1442. 
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    The spectrophotometric titrations have been performed at 298.15 Kin buffered aqueous solution(pH=7.20) to give the stability constants(lg Ks) for the supramolecular system formed by mono-[6-phenylseleno)-6-deoxy]-β-cyclodextrin(1), nono-[6-( p-chlorophenylseleno)-6-deoxy]-β-cyclodextrin(2), mono-[6-(naphthylseleno)-6-deoxy] β-cyclodextrin(3), and mono-[6-(benzylseleno)-6-deoxy] β-cyclodextrin(4) with a series of aliphatic alcohols.
    Enantioselective Synthesis of 2-Methyl-2-(2-nitroethenyl)-1-benzocyclones
    LIU Da-Xue, WANG Rui
    1998, 19(9):  1443-1445. 
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    Optical active 2-methyl-2-(2-nitroethenyl)-1-tetralone and 2-methyl-2-(2-nitroethenyl)-1-indanone were synthesized via enantioselective addition elimination reaction between nitroenamine(4) and the enolate of 2-methyl-1-benzocyclone(2). The chromatographic separation yield is 17% 73%. The Econfiguration of the olefinic bond and the enantiomer excess(8%-60%) of products were determined by 400 MHz 1HNMR.
    Studies on Artificial Imitation of Glutathione Peroxidase by Using Selenium containing β-Cyclodextrin
    LIU Jun-Qiu, NING Yun-Gang, SHI Cheng-Bo, LUO Gui-Min, YAN Gang-Lin, SHEN Jia-Cong
    1998, 19(9):  1446-1448. 
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    6-Selenium bridged cyclodextrin was synthesized by regioselective tosylation of β-cyclodextrin and NaHSe displacement on the basis of the active site structure of glutathione peroxidase(GPX). The compounds displayed a higher activity of GPXthan Ebselen(PZ51), its GPXactivity was 4.3 times more than that of PZ51. The structure of the mimic was characterized by elemental analysis, IRand 1HNMR. The Se content and its valence in the mimic was determined by X-ray photoelectron spectrum.
    Studies on the Isothermal Solubility and the New Phases in the Ternary System MgCl2 CO(NH2)2 H2O at 25 ℃
    ZHANG Feng-Xing, WEI Xiao-Lan, GUO Zhi-Zhen, SHI Qi-Zhen
    1998, 19(9):  1449-1452. 
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    The solubilities and refractive indices, densities of the saturated solutions in the title ternary system have been investigated isothermally at 25 ℃. In the ternary system, there are two new phases being formed, MgCl2·CO(NH2)2·4H2O(compound A) and MgCl2·4CO(NH2)2·2H2O(compound B). Compound Bis found for the first time. The two compounds are characterized by IRspectra, DTA, DSC, X-Ray diffraction etc. The solubility diagram is consisted of four crystallization surfaces corresponding to MgCl2·6H2O, ternary compounds A, Band CO(NH2)2, and three invariant points corresponding to the eutectic solutions saturated with MgCl2·6H2O+A, A+B, B+CO(NH2)2.
    Studies on White Powdery Tungstic Acid(→) Stability and Photochemistry of Decatungstic Acid in Aqueous Solution Containing Polyvinyl Alcohol
    YUE Bin, TANG Li-Hao, ZHU Si-San, LIN Xin-Rong
    1998, 19(9):  1453-1456. 
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    Decatungstic acid can be formed by the reaction of white powdery tungstic acid in aqueous solution containing polyvinyl alcohol. The stability and photochromism of decatungstic acid in homogeneous system have been studied through UV-Vis spectra, ESR, pHtitration and W(Ⅴ) determination. The results show that the reduction degree of decatungstate anion corresponds to the acidity of the solution. One-electron reduced form is produced mainly at high pHvalue while two-electron reduced form mainly at low pHvalue.
    Effect of Additives on Cloud Point of Dodecylpolyoxyethylene Polyoxypropylene Ether Nonionic Surfactant
    LI Ying, LI Gan-Zuo, MU Jian-Hai, XU Hong-Kui
    1998, 19(9):  1457-1461. 
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    The effects of additives, such as salts, alcohol, carboxylic acid and ionic surfactant on the cloud ponit of nonionic surfactant dodecylpolyoxyethylene polyoxypropylene ether were studied in the paper. It was found that the change of CPvalue coursed by salts followed the Schott additivity regulation and was determined by the characteristic of salts(such as charge of ions) and surfactants(such as group numbers of oxyethylene and oxypropylene); the effects of organic substances on the CPvalue of nonionic surfactant varied if the additives have a different kind of hydrophilic head or carbon chain length; the formation of mixmicell could be the reason why ionic surfactants greatly increased the CPvalue of nonionic surfactant, but more detail studies were needed to find the regulation.
    A Study of Pulsed Laser Deposition of LiMn2O4 Thin Films
    YANG Hai-Jun, ZHOU Ming-Fei, QIN Qi-Zong, CAI Run-Liang, WU Hao-Qing
    1998, 19(9):  1462-1466. 
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    The LiMn2O4 films have been prepared by 355 nm pulsed laser deposition on the heated stainless steel substrate in an O2 gas environment. The formation of the ablated species in the laser ablation process and the effect of O2 ambient have been investigated by both quadrupole mass spectrometry and optical emission spectroscopy. The measured mass spectra show that the main ablation products are Mn+, Li+, O2, O, LiO2, LiMnOand lithium atomic cluster. The dependence of ambient O2 pressure on the emission intensities of Mn containing species shows that the reactions of the ablated species with oxygen play an important role in the film deposition. The deposited LiMn2O4 films are characterized by XRDand cyclic voltammetry.
    Synthesis and Characterization of X-type Barium Ferrite Nanocrystals
    XIONG Gang, YANG Xu-Jie, WANG Xiao-Hui, LU Lu-De, WANG Xin
    1998, 19(9):  1467-1470. 
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    Nanostructured samples of X-type Ba2Co2Fe28O46 hexagonal ferrite have been prepared by using the stearic acid gel method. The nanocrystalline hexaferrite powders obtained at 750 ℃ were spherical in shape with grain sizes in the range of 15～25 nm. With increasing calcining temperature, the particles become a plate-like structure. The magnetic properties of Xtype barium ferrite nanocrystals were measured by using Vibrating Sample Magnetometer(VSM). The results indicate that the magnetic properties of the title products are different from those of the common X-type hexaferrites with a lower specific saturation magnetization( σs). Coercivity force( Hc) and the specific saturation magnetization( σs) of the products are influenced by the particles sizes.
    Detection of Alkali and Alkaline earth Ions with Oil soluble Fluorescence Probe Molecule in Aqueous Solutions
    JIANG Yong-Cai, WANG Peng-Fei, WU Shi-Kang
    1998, 19(9):  1471-1474. 
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    An oil soluble flavone derivative (FL-C) with lariat ether was able to coordinate with β-CDin aqueous solution to form 1:1 host-guest complex. Because it was still located at the outside of β-CD, the lariat ether keeps the complexation ability with alkali and a alkaline-earth cation, leading to the fluorescence intensity change of this compound. The results indicated that the using of oil-soluble probe in β-CDaqueous solution for the detection of alkali and alkaline earth cations was successful.
    A Kinetic Study on the Photocatalytic Degradation of Methomyl
    ZHANG Man-Ping, ZHAN Run, XIA Zong-Feng, Gary Low
    1998, 19(9):  1475-1478. 
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    The photocatalytic degradation of a wisely used pesticidemethomyl was studied in this paper. The degradation was catalyzed by titanium dioxide. The products, kinetics and factors that affect the rate of degradation was discussed. Methymol can be photooxided into inorganic materials in 10 minutes under the catalysis of titanium dioxide. FTIRstudy shows that the products are NH4+, SO42- and CO2. The degradation is first order reaction and the kinetic reaction curve was modeled. Some cations and anions can affect the reaction rate. Most ions retard the rate but Cu2+ and Cl- at low concentrations stimulate the reaction.
    Chemical Liquid Deposition and Hydrophobicity of Zeolites
    QIN Ying, YUE Ying-Hong, GAO Zi
    1998, 19(9):  1479-1483. 
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    Hydrophobic zeolites were prepared from mordenite and ZSM-5 by chemical liquid deposition with SiCl4. Hydrophobicity Index( Ih) of the zeolites was determined from the competition adsorption of gasous n-heptane and water under specific conditions. The influences of the nature and Si/Al ratio of the original zeolites, pretreatment and deposition conditions on hydrophobicity were studied. the hydrophobic zeolites were characterized with XRD, IR, NH3-TPDand N2 adsorption methods, and their adsorbability for phenolic compounds from waste water was tested. The hydrophobicity of HZSM-5(Si/Al ratio is 100) treated by chemical liquid deposition is better than the commercial silicalite prepared from highly siliceous HZSM-5 by severe steaming at high temperture. Its Ih value is 1.7 times higher and its adsorption capacity for p-cresol in dilute solution of 0.2—0.4 mmol/Lis 1.3—1.7 times greater as compared to commercial silicalite.
    Studies on Photoelectrochemical Behavior and Surface Image of Electrodeposited Nanocrystalline TiO2 Films
    LUO Jin, ZHOU Jing, ZU Yan-Bing, LIN Zhong-Hua
    1998, 19(9):  1484-1487. 
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    The photoelectrochemical behavior and surface image of electrodeposited nanocrystalline TiO2 films prepared under different conditions were studied by using photocurrent spectroscopy, transparent spectroscopy and scanning probe microscopy. The particle sizes of the nanocrystalline TiO2 films electrodeposited from 0.05 mol/L TiCl 3+Na2CO3(pH=2.2) and from 0.05 mol/L TiCl 3+NaOH(pH=2.2) were about 50—100 nm. The photoelectrochemical behavior of the TiO2 films was related to the surface structures. The TiO2 film electrodeposited at 0.1 Vvs. SCEin 0.05 mol/L TiCl 3+NaOH(pH=2.2) was of better photoelectrochemical conversion efficiency. It was shown that the photoelectrochemical behavior of nanocrystalline TiO2 films was different from those of compact semiconductor electrodes.
    Dimeric Reaction and Quantum Chemical Study of the R-Thiazolidine-2-thione-4-carboxylic Acid
    LI Ye-Zhi, GUO Chun-Xiao, HU Xue-Shan, HUANG Hua-Min
    1998, 19(9):  1488-1491. 
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    R-Thiazolidine-2-thione-4-carboxylic acid reacted with acylchloride to form bistetrahydrothiazolidine-2-thione-2-dioxo hydropyrazine. With molecular orbital PM3 method, the electronic structure of products and reactants have been studied.
    Molecular Mechanics Study on Conformation of Calixarenes
    YU Xiao-Dong, WU Cai-Ying
    1998, 19(9):  1492-1494. 
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    In this paper, molecular mechanics method was used to investigate the conformations of six calix[4]arene derivatives. The results show that the amount of hydrogen bonds has an effect on the conformations of calix[4] arene. The conformation of the tetra-substituted calix[4] arene was determined by the conformation of the reaction intermediate.
    Ab Initio Study on Transition Metal Carbene Cations
    LI Ji-Hai, FENG Da-Cheng, FENG Sheng-Yu
    1998, 19(9):  1495-1497. 
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    The geometries and bonding characteristic of the first-row transition metal carbene cations MCH2+ were studied by ab initio (HF/LANL2DZ). All of MCH2+ are coplanar. In the closed shell structures the σ and π obitals are all doubly occupied. Therefore, they are “perfect” double bonds, but in the open shell, they are “imperfect”, because there are only three electrons in σ and π orbitals. It was mainly the π-type overlap between2 px of Cand 4 px, 3dxz of Mthat formed the π orbitals. The dissociation energies of C—M+ bond appear periodic trends from Sc to Cu. The bond dissociation energies of C—M+ calculated at PMP3/LANL2DZlevel are basically closed to the experimental values.
    The Investigation of the Various Structures of DNA Molecules(Ⅲ) The Coil toroid Transition of λ-DNA Induced by the Biomolecular Probe AO
    FENG Xi-Zeng, LIN Zhang, MA Jin, WANG Chen, BAI Chun-Li
    1998, 19(9):  1498-1500. 
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    The helix and structure transition of λ-DNAin AOsolutions were investigated by SEMand AFMmethods. Using SEM, we observed the turn and globular as well as toroidal condensates of λ-DNAinduced by AO. The fine structures of these condensates were further observed by using AFM. Our results reveal that the mechanism of the coil-toroid transition of λ-DNAresulted from the changed environment is related to the shrinking and collapsing process as well as the self-assembling process of these condensates.
    A Novel Method for Determining Critical Micelle Concentrations of Anionic Surfactants by Ultra filtration Membrane
    FANG Yun, XIA Yong-Mei, WU Yun-Lan, NI Bang-Qing, ZHU Wei-Bing
    1998, 19(9):  1501-1503. 
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    Anovel method for determining critical micelle concentrations(cmc) of surfactants by membrane is developed. Micellar aggregates and isolated molecules in micellar solutions of surfactants are separated by ultra-filtration membrane with suitable pore diameter, followed by quantitatively detecting of surfactants in ultra-filtrated liquid by anion cation two phase titration, thus, cmc of anionic surfactants can be known quickly and accurately. This method directly depends on the difference of sizes between micelle and molecule of a surfactant, but not on other sharp break in the plot of properties vs. concentration of a surfactant, hence, it is not necessary to get only one cmc from a series of surfactant solutions.
    Studies on Complexation Between β-Cyclodextrin and Sodium Dodecyl Sulfate by Microcalorimetry
    ZHU Xiao-Feng, XU Xu, LIN Bing-Cheng, G. Wenz, S. Wehrle
    1998, 19(9):  1504-1506. 
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    The interaction between β-cyclodextrin( β-CD) and sodium dodecyl sulfate(SDS) was studied by microcalorimetry, a Host-Guest binding reaction with 1:2 stoichiometry was calculated, the first and second stability constants are 15.50 mol-1 ·Land 7.95 mol-1 ·Lrespectively. According to the experimental results, several related thermodynamic parameters were also obtained and a possible inclusion model was presented as well.
    A Study of the Relationship Between Chemical Structure and Properties for Mesogen-jacketed Liquid Crystal Polymers
    WAN Xin-Hua, ZHOU Qi-Feng, ZHANG Dong, ZHANG Yong, FENG Xin-De
    1998, 19(9):  1507-1512. 
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    Seven novel mesogen-jacketed liquid crystal polymers were designed and synthesized. The effects of chemical structure and steric features on liquid crystalline phase forming were studied. It was found that the introduction of polar or polarable group at the end of the mesogen units could increase the melting point and clear point of monomers. The bigger the axial ratio of mesogen units, the higher the melting point and clear point. The stability of liquid crystalline phase was enhanced by polymerization. The stronger of the polarity, rigidity and steric requirement of the mesogen units, the higher the glass transition temperature of the polymers. The amide group can increase the melting point of monomers and glass transition temperature of polymers no matter it was used as the end group or linkage of the mesogen units. However, the stability of liquid crystalline phase was increased by the amide end groups and decreased by the amide linkages.
    Studies on Components and Molecular Weights of Polysaccharides from Lentinus Edodes
    ZHANG Li-Na, ZHANG Ping-Yi, LI Xiang, PAN Su, ZHU Rong-Ping
    1998, 19(9):  1513-1517. 
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    Four heteropolysaccharides(L-FⅠ_L-FⅣn ) and two glucans(L-FⅤ and L-FⅥn ) were isolated from the fruit bodies of lentinus edodes by using aqueous 09% NaCl, 85% ethanol, hot water(120 ℃, high pressure), aqueous 1% ammonium oxalate, aqueous 5% NaOH/005% NaBH4 and 2% NaOH/2% urea, respectively. The results analyzed with IRand HPLCshowed that the heteropolysaccharides consist of Dglucose, glucuronic acid, xylose, mannose and galactose and rhamnose, and the D-glucose content in the polysaccharides increases with the progress of isolation process. The weight average molecular weights Mw, root-mean-square radii of gyration 〈S2〉1/2, second Virial coefficients A2 and number average molecular weights Mn of the polysaccharides were studied by using light scattering and membrane osmometry. The Mw values of the samples of L-FⅡ, L-FⅢ, L-FⅤ and L-FⅥ n are 19.7×104, 19.23×104, 13.64×104 and 13.67×104, respectively. The polydispersity indexes of the polysaccharides Mw/ Mn lie in the range of 3～5.
    Formation of Monodispersed Polymer Particles in Emulsifier free Emulsion Polymerization
    ZHANG Mao-Gen, WENG Zhi-Xue, HUANG Zhi-Ming, PAN Zu-Ren
    1998, 19(9):  1518-1521. 
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    The nucleation mechanism of polymer latex particles and formation processes of monodispersed latex particles in MMA/BAemulsifier free emulsion polymerization in the presence of small amount of water-soluble comonomer(such as sodium sulfonated polyethylene glycol allyl ether glycerin succinate) were investigated with Coulter LS230 laser particle size analyzer. The colloidally stable polymer latex particles were formed from multi step particle formation mechanism: the coagulation of colloidally unstable precursor particles subsequent to their formation by homogeneous nucleation, and growth due to both aggregation and propagation. The particle monodispersion was not formed in the early stage, but formed through a process of increasing and then decreasing in particle polydispersity, U= Dw/ Dn. This can be ascribed to the competition of homogeneous nucleation coagulation propagation-aggregation, and it also leads to the periodic-nucleation-phenomena in the early stage of polymerization.
    Studies on the Problem About the Instrumental Constant in Vapour Pressure Osmometry
    WANG Zhi-Liu, CHENG Rong-Shi
    1998, 19(9):  1522-1525. 
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    The problem about the molecular weight dependence of the instrumental constant Kof vapor pressure osmometry was studied in Knauer VPOapparatus by using four low molecular weight organic compounds and six narrow molecular weight distribution oligometic polystyrene samples with the known average molecular weights. There exists the effect of solute adsorption in VPO, which leads to the result that the instrumental constant Kis apparently dependent upon the molecular weight of the solute. The dependence of the Kon the molecular weight of the solute was eliminated by modifying a factor of solute adsorption.
    Crystal Structures of Isotactic Polystyrene Ultrafine Particles
    WANG Song, DAI Qing-Ping, HONG Jian-Min, YAN Xiao-Hu, CHENG Rong-Shi
    1998, 19(9):  1526-1528. 
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    Ultrafine particles, with average equivalent diameters in the range of 60～330 nm, prepared by freeze-drying very dilute(about 2×10-5 g/mL) solutions of isotactic polystyrene in benzene at 0 ℃ were studied by TEMand DSC, respectively. It was found that two different structures of widely different thermal stabilities can form at identicaltemperatures. One melt(mode A) at 220 ℃ just as the recognized structure of isotactic polystyrene(31 helix). The other(mode B) melt at 65 ℃ and produced distinct electron diffraction patterns which, however, differ decisively from those provided by crystals A. The melting point of crystals Bis also significantly lower than those of iPSdried gel crystals, which give an endotherm at 120 ℃ in calorimetric measurements. According to 13 C NMR measurement, the material used in this study should be practically fullyisotactic.
    Interaction of SDS with Polyelectrolyte Complex Based Diazoresin
    CAO Wei-Xiao, YANG Lei
    1998, 19(9):  1529-1531. 
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    Anovel polyelectrolyte complex from diazoresin(DR) as cationic polyelectrolyte and poly(sodium styrene sulfonate)(PSS) as anionic polyelectrolyte was prepared. It was found that the complex which is indissolve in water or any organic solvent, will dissolve in SDSaqueous solution. The DR-PSS/SDSaqueous solution, as an unexpected result, exhibits extraordinary thermostability as well as high photosensitivity and can be used directly as a composition in photoimaging technique. Aproposed explanation for soluble of DR-PSSin SDSaqueous solution and high thermostability was proposed and discussed preliminary.
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