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Table of Content

    24 February 1999, Volume 20 Issue 2
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    Articles
    The Process of Conformational Change of Human Hemoglobin Induced by VanadyLIon Binding and the Effect of 2,3-Diphosphoglycerate
    XUE De-Ping, LIN Hua-Kuan, WANG Kui
    1999, 20(2):  167-171. 
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    The process of the conformational change of human hemoglobin as the result of its interaction with vanadyLIons with and without DPG was determined by means of stopped flow measurement of the intrinsic fluorescence of Hb. The vanadyl binding causes monotonous quenching of the intrinsic fluorescence of DPG depleted Hb. It is noteworthy that the binding of DPG to Hb makes the process to be biphasic one. The first step is also featured by the quenching of intrinsic fluorescence. In the second step of DPG Hb system, the intrinsic fluorescence stops to decrease and turns to increase very slightly. The process was explained on the basis of vanadylbinding induced conformation change and the stabilizing effect of DPG and its hydrolytic product 3PGA to the tetrameric structure of Hb.
    Hydrothermal Synthesis and Characterization of Complex Fluorides Li2BeF4
    SHI Zhan, FENG Shou-Hua
    1999, 20(2):  172-175. 
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    The complex fluorides Li2BeF4 have been hydrothermally synthesized at 140-200 and characterized by XRD, IR, SEM And XPS. The hydrothermal conditions such as reaction temperature, reaction time, and the ratios of initial composition were investigated. The vibrations of crystallization curves were observed.
    Synthesis and Crystal Structure of Gadolinium Mononuclear Complex with Triethylenetetraaminehexaacetic Acid
    WANG Rui-Yiao, ZHANG Hua-Jie, JIN Tian-Zhu, ZHOU Zhong-Yuan, ZHOU Xiang-Ge
    1999, 20(2):  176-180. 
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    The gadolinium complex with triethylenetetraaminehexaacetic acid (abbreviated as H-6ttha), (NH4)2[Gd(Httha)]·6H2O was synthesized in aqueous solution, and its crystal structure was determined by X-ray fourcycle diffraction method. The crystaLIs monoclinic, space group P21/c, with a=1.0400(4) nm, b=1.2761(4) nm, c=2.3132(4) nm, β=90.89(3), V=3.070(2) nm3, Z=4, Dc=1.709 g/cm3. The complex was a mononuclear molecule, each gadolinium ion is coordinated by four nitrogen atoms and five carboxyl oxygen atoms from one Httha, forming a coordination polyhedron of mono capped square antiprism.
    A Study on the Phase Equilibrium of the Ternary System of Yb(ClO4)3-BAPHDCA H2O3BAPHDCAH2O(30℃) and the Preparation of Ternary Complex
    CUI Bin, CHEN Kai-Xun, TANG Zong-Xun, GUO Zhi-Zhen
    1999, 20(2):  181-185. 
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    The solubility properties of the title syste MAt 30 in the whole concentration range have been systematically investigated by phase equilibrium method. The results indicated that there is a ternary complex, which is incongruently soluble in water, formed in the system:Yb(BAPHDCA)2(ClO4)34H2O. Under the direction of phase equilibrium results, the complex has been prepared and characterized by chemical and elemental analysis, IRspectra, TG-DTG and X-ray powder diffraction.
    Studies on the Kinetics of Dissolution and Transformation of 2MgO2·B2O3·MgCl21·4H2O in Water at 60
    LIU Zhi-Hong, XIA Shu-Ping, GAO Shi-Yang
    1999, 20(2):  186-189. 
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    The kinetic of dissolution and transformation process of 2MgO·2B2O3·MgCl2·14H2O in water at 60 was studied. The solution samples were taken at different time for chemical analysis.The solid phase at different stages was separated and identified.The experimental results show that 2MgO2·B2O3·MgCl2·14H2O dissolved incongruently in water. The midproduct is MgO·B2O3·4H2O and Mg(OH)2.The finaLInversion product is pinnoite, MgO·B2O3·3H2O. The mechanism of dissolution and transformation was proposed and discussed. The kinetic equations of dissolution and crystallization were obtained.
    Influence of Rare Earth on Specific Rotation of Amino Acids
    LI Hong-Guang, ZHANG Hua-Jie, LIU Hui, JIN Tian-Zhu
    1999, 20(2):  190-192. 
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    The influence of ionic strength, acidity and concentration of rare earth on the specific rotation of L-methionine and L-histidine were investigated. The results of the specific rotation determined illustrate that the configuration of L-methionine and L-histidine do not change after the interaction with rare earthions.
    Studies on Supramolecular Chemistry of Calixarenes (Ⅰ) Liquid Membrane Transport of K+, Na+Ions with p-tert-Butylcalix[n]arenes and Their Derivatives as Carriers
    SHI Xian-Fa, WANG Yu-Ping, LIU Yan-Sheng, JIANG Zhong-Liang, TAO Ling, SUN Hong-Bao
    1999, 20(2):  193-195. 
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    The liquid membrane transports of K+ions by p-tert-butylcalix arene as carrier are investigated by the bubbling pseudo-emulsion liquid membrane. This transport process is a protoncoupled transport with a coupled flow of protons in opposite direction. The driving force for the transport is the pHgradient between the source phase and the receiving phase. The selected transport for K+ion or Na+ion by p-tert-butylcalix[n]arene(n=4, 6, 8) as carriers are investigated.
    Synthesis and Crystal Structure of In[(C2H5O)2PS2]3
    LIU Xing-Zhi, XUE Hong, ZHAO Jin, SONG Yu-Lin, ZANG Shu-Liang
    1999, 20(2):  196-198. 
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    The complex In[(C2H5O)2PS2]3was synthesised and characterized by IR, MS, TGDTA and elementary analysis. The crystal structure was determined and indicated that In[(C2H5O)2PS2]3is monoclinic, space group C2/c with a=0.8160(2) nm, b=1.8785(4) nm, c=1.7929(4)nm,α=γ=90.00(0)°, β=92.15(3)°, V=2.986(1) nm3, Z=4, Dx=1.538 g/cm3, F(000)=1360. The structure was refined to R=0.059 and Rw=0.063. There are four chemical units in each crystal celLIn which In(Ⅲ) ion coordinates with six sulfur atoms and the number of coordination is 6. The molecular contiguration of crystaLIs octahedral.
    HELP Applied to Traditional Chinese Medicine Analysis Determination of Components of Cordyceps Sinensis
    GONG Fan, PENG Yuan-Gui, CUI Hui, LIANG Yi-Zeng, Alexander K.M.Leung, Foo-timChau
    1999, 20(2):  199-203. 
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    The multicomponent qualitative and quantitative analysis of Stroma and Caterpillar body of Cordyceps sinensis were carried out by Heuristic Evolving Latent Projection(HELP) method. The procedure for resolving the twoway chromatogram/spetrum data obtained from the hyphenated instruments with HELP was developed in detail. It showed that HELP method could be used to examine the purity of chromatographic peaks, resolve overlapping peaks and finally obtain the pure chromatographic profiles and spectra for all the chemical components in the studied system. The separation ability of chromatography can be greatly improved. Moreover, the accuracy of qualitative and quantitative results could also be enhanced by means of this method. HELP method could be a promising method to the simultaneous multicomponent analysis for traditional chinese medicine.
    A Study of Binding Action and Selectivity of Trimethoprim Molecular Template Polymer
    ZHOU Jie, HE Xi-Wen, ZHAO Jie, SHI Hui-Ming
    1999, 20(2):  204-208. 
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    Amolecularly templated synthetic polymer receptor highly selective for trimethoprim was prepared by a molecular selfassembly imprinting technique. The selective binding characteristics of the template polymer were evaluated by Scatchard analysis, 1HNMR study and Ultraviolet spectrometry. The results showed that a class of same binding sites, which could specificially bind to trimethoprim by cooperative hydrogen bonding, were formed in the polymer, and its dissociation constant was estimated to be 2.22×10-4mol/L. The selective binding experiments for substrates indicated that the polymer gave much higher affinity and selectivity for trimethoprim than for sulfanilamide and sulfapyridine. It is possiple to be a good adsorption and binding materiaLIn the selective enrichment and determination of trace trimethoprim in complex biosamples.
    The Investigation of a New Flowinjection Analysis Electrogenerated Chemiluminescence Method and the Determination of S2-
    ZHENG Xing-Wang, ZHANG Zhu-Jun
    1999, 20(2):  209-213. 
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    By contriving a novel electrolytic flowthrough cell, BrO-, an unstable reagent, had been online produced with galvanostatic electrolysis method and flowinjection technique in alkaline KBr solution. The concentration of BrO-can be online adjusted by this flow system. At the same time, it was found that sulfide had a strong enhanced effect on the emission intensity of CLreaction between BrO-and LuminoLIn pH=9.60 Na2CO3NaHCO3medium. Based on this observation, a new flowinjection analysis ECL method for the determination of sulfide ion has been proposed in this paper. The detection limit of sulfide ions was 0.100 mol/L, the linear range of determination sulfide ions was 0.310-93.0 mol/L with the relative standard deviation of 2%[c(S2-)=3.10mol/L, n=11].
    Nonprotected Fluid Room Temperature Phosphorescence of Bromonaphthalene and Its Medium Effects
    MOU Lan, CHEN Xiao-Kang, LI Long-Di
    1999, 20(2):  214-217. 
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    Astrong and stable room temperature phosphorescence(RTP) signal of bromonaphthalene(β-BrN) aqueous solution with peak wavelengths of λex/λem=275.0 nm/(494/3, 517/6) nm can be induced only by using Na2SO3as an oxygen scavenger and irradiating the solution for some time with the light source of apparatus. The RTP intensity and irradiation time required to acquire a stable RTP signal are very sensitive to the kind and amount of organic solvent added to the system. For a β-BrN/Na2SO3aqueous solution system containing 25% acetonitrile, a short irradiation time is needed and a strong and stable RTP signaLIs triggered quickly. The RTP intensity is linear to the BrN concentration in the range 8.0×10-8-1.6×10-5mol/Lwith the detection limit of 4.7×10-8mol/L.
    Determination of Hainanmycin in the Aqueousalcohol Solution by Fourier Transform Infrared Spectroscopy
    QIU Jiang, DING Le-Hong, YE Qin, ZHANG Si-Liang
    1999, 20(2):  218-220. 
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    Fourier transform infrared(FTIR) spectroscopy equipped with horizontal attenuated total reflection(ATR) accessory was applied to the multicomponent quantitative analysis in organic phase. Anovel method was developed to directly determine the Hainanmycin(HNMS, an insoluble antibiotic from the fermentation) in water and ethyl alcohol solution. Calibration models were established on the basis of partial least squares with infrared spectra(IR) and secondderivative absorbance spectra(DIR) of the standard mixtures. The better predicted results is obtained especially at lower concentration of HNMS by DIR method. The standard errors of prediction of HNMS by IRor DIRare 0.18 and 0.19 g/L, respctively. The standard errors of prediction of water and alcohol are 0.0011 volume ratio by either quantitative method. The method is rapid and convenient without any pretreatment.
    Spectrophotometric Determination of Proteins by Using Nitrosulfophenol C
    HU Qiu-Luan, LI Na, ZHAO Feng-Lin, LI Ke-An
    1999, 20(2):  221-223. 
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    In this paper, it is found firstly that the nitrosulfophenol Ccan react with proteins to for MA pure blue complex in BrittonRobinson buffer solution at pH3.4 and room temperature, which gives maximuMAbsorption peak at 675 nm with 100 nm to red shift compared to that of nitrosulfophenol C. According to studies on optimum conditions, a new spectrophotometric method for determination of proteins was established. The standard working curves of eight kinds of proteins with larger linear ranges and higher sensitivity were determined. The new method was successfully applied to the determination of protein in human serum samples with satisfactory results in agreement with those of the classical coomassie brilliant blue G-250(CBB G-250) method.
    Electrocatalytic Oxidation and Trace Determination of Catecholamine Neurotransmitters at Osmium Complex Polymer and Nafion Duallayer Membrane Carbonbase Electrode
    NI Jing-An, JU Huang-Xian, CHEN Hong-Yuan, Dnal Leech
    1999, 20(2):  224-226. 
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    The fabrication and electrocatalytic characteristics of osmium complex polymer [Os(bpy)2(PVP)10Cl]Cl(OsP)orOsP2N afion duallayer membrane modified carbonbase(glassy carbon or graphite) electrodes were studied. The electrocatalytic behaviour of these modified electrodes to the oxidation of catecholamines(dopamine, epinephrine and norepinephrine) was investigated. The kinetic parameters of these electrocatalytic reactions were obtained. The OsP-Nafion duallayer membrane modified electrodes could eliminate efficiently the interference of ascorbic acid and could be used in quantitative determination of trace catecholamine levels. The modified elecrodes showed excellent sensibility, selectivity and stability.
    Studies on Synthesis and Funigicidal Activity of S-Allyl-O-substituted Phenyl Thiophosphates(onates)
    HE Zheng-Jie, LIU Ju-Xiang, ZHOU Zheng-Hong, TANG Chu-Chi
    1999, 20(2):  227-231. 
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    The isomerization/chlorination of O,O-diallyl thiophosphates(onates) 6with phosphorus oxychloride gives Sallyl thiophosphorochloridate(nochloridate)7 and Oallyl phosphorodichloride 8. After removal of 8 under the reduced pressure, the crude 7 is purified by column chromatography on silica gel, then 7 reacts with substituted phenoLIn chloroform in the presence of triethylamine giving eighteen new title compounds 9. The bioassay results against five plant disease fungi including P. Zeae, P. Piricola, R. Solani, A. Solani and D. Arachidicala show that the title compounds 9 possess some or excellent fungicidal activity at 0.005% concentration.
    Stereochemistry of the Heterocyclic Alcohols Containing Piperidine Unit
    GAO Shou-Hai, HU Wen-Xiang, YUN Liu-Hong
    1999, 20(2):  232-236. 
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    The stereochemistry of the heterocyclic alcohols(1_4) containing piperidine unit was studied on the basis of the results of molecular mechanics and quantum chemistry calculations. The results showed that there existed the nonclassical orbital superconjugated interactions between the nitrogen atoMAnd oxygen atom which caused the conformations to be more stable when the hydroxylic group lay at axial than at equatorial with respect to the piperidine ring in compound 1 and compound 3. If the axial hydrogen atoms at C2and C6positions in the piperidine ring were substituted, or the molecular existed in the polar solutions, this nonclassical orbital superconjugated interactions would be much weak even diminished. In this case, the conformations were more stable when the hydroxylic group at equatorial than at axiaLIn these compounds.
    Synthesis of a Styrylthiophene Monomer and Corresponding Polyurethane and Their Optical Nonlinearity
    WANG Jiang-Hong, ZHOU Jia-Yun, ZHANG Xin-Xin, ZHAI Jian-Feng, LI Zhao, SHEN Yu-Quan, XU Gang
    1999, 20(2):  237-242. 
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    Anovel trans-7-[4-N,N-di-(β-hydroxy ethylamino-benzene)]-ethenyl-ethenyl-3,5-dinitrothiophene(HBDT) monomer and corresponding prepolymer, polyurethane with the monomer covalently incorporated were synthesized and characterized. The reaction temperature affecting monomers formation were discussed. Since thiophene has a lower delocalization energy than that of benzene, it can offer more effective conjugation and higher nonlinearity than that of benzene in donoracceptor organic compounds, and forms objective molecules with reasonable optical, thermal stability. The monomer and polyurethane exhibited a good solubility in common organic solvents and thermal stability. The high optical quality films of the polyurethane were fabricated and coronapoled. The UVVis absorption peaks (530 nm) of the monomer in methanol and the without poling polyurethane films didnt change basically. The second, thirdorder nonlinear optical susceptibility, (3), of HBDT was measured by solvatochromic method and DFWMmethod, respectively, they were 8.443×10-45esu,1.016×10-12esu(c=3.96×10-3mol/L),3.93×10-32esu. respec-tively.
    Catalyzed Oxidation by Rhus Vernicifera Laccase(ⅹⅢ) Effects of Fe2+Ion on the Catalytic Oxidation by Laccase
    TU Chu-Qiao, LIANG Hong, WANG Guang-Hui
    1999, 20(2):  243-247. 
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    The effects of FeSO4on the oxidation of 5,6-dibromo 2,3-dicyanohydroquinone(DDBQH2) catalyzed by Rhus vernicifera laccase were studied spectrophotometryly under condition of pH4.50. The results show that under the condition of experiments, SO42-ion has little effect on the enzymatic reaction, but Fe2+ion has obvious inhibition, the nature of inhibition is competitive type. The results demonstrate that the inhibition is realized through the reduction of product of enzymatic reaction by Fe2+ion.
    A Novel Structure Motif of Metallothionein PbMT
    HE Wei-Guo, CHU De-Ying, YANG Jing-Yue, YAO Dan-Feng, SHAO Mei-Cheng
    1999, 20(2):  248-250. 
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    Lead(Ⅱ)binding behaviors of rabbit liver thionein2(apo-MT2) has been studied by monitoring the changes of their electronic absorption(UV) and circular dichroism(CD) spectra. Two MT species, Pb7-MT and Pb7-MT, are observed upon the binding of Pb to apoMTat different pH. The formation of Pb7-MT -or Pb7-MT is closely realted to the amount of deprotoned sulfhydryl groups. Pb7-MT is formed only at high pHcharacterized by UV 340 nm shoulder and CD 245 nm band. Then the formation of a new leadmetallothionein complex, namely PbMT, is observed at low pH (pH<6). This new species is characterized by a strong circular dichroism(CD) cotton effect at 395 nm(-), 310 nm(-) peaks and 350 nm(+), 250 nm(+) doublehump and a unique electronic absorption(UV) spectruMAt 325 nm, 375 nMAnd 400 nm shoulder. From their characteristic peaks in UV and CD spectra, it is deduced that Pb2+in Pb7-MT is coordinated by four sulfhydryl groups in Td microsymmetry, while multiple Pb2+coordination including twocoordination mayb.
    Lewis Acidcatalyzed Asymmetric Cycloaddition Reaction of 1-(SR)-p-Tolylsulfinyl-3-penten-2-one with Cyclopentadiene
    PEI Wen
    1999, 20(2):  251-253. 
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    The asymmetric cycloaddition reaction between 1-(SR)-p-tolysulfinyl-3-penten-2-one(1) and cyclopentadiene was performed by the catalysis of Lewis acids 2. The diastereoselectivity dependent on the size of aryl substituent involved in the chiral ligands was discussed. The cycloadduct 3 was achieved in a high yield and a high optical purity. The absolute configuration of the cycloadduct 3 was confirmed.
    NO Adsorption and the Distribution of NickeLIons on USY Zeolite and γ-Al2O3 and Their Mixture
    NIU Guo-Xing, CAO Zhi-Song, LI Quan-Zhi, HUANG Yao, HUANG Yu-Fang
    1999, 20(2):  254-259. 
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    The distribution of Ni2+ions on USY zeolite, alumina and their mixed carriers is studied according to their NO adsorption. When Ni2+ions locate on SⅡ、SⅡ、(SⅠ')、 sites of USY zeolite or on the surface of alumina, the IRspectra of their NO adsorption show the bands at 1905, 1900 or 1855-1871 cm-1respectively. When NiO loading on NiO/Al-2O-3samples is less than 8%, the Ni2+ion distribution has an equilibrium between the surface and the bulk of γ -alumina. The proportion is about onethird. On USY zeolite, Ni2+ions prefer to occupy its S-Ⅰ sites rather than its S-Ⅱ, S-Ⅱ' and S-Ⅰ' sites. The tendency strengthens obviously with the increase of NiOloading. On MS mixed carriers, more Ni2+ions located on the surface of alumina than on S-Ⅱ and S-Ⅱ', S-Ⅰ' sites of USYzeolite. The number of Ni2+ions on the surface of alumina or on S-Ⅱ',S-Ⅰ' sites of USY zeolite increases greatly with increasing.
    Theoretical Studies on the Structures and Electronic Spectrafor Substituted Fullerene C58BN
    CHEN Zhong-Fang, CHEN Lan, MA Ke-Qin, LI Fang-Xing, PAN Yin-Ming, ZHAO Xue-Zhuang, TANG Ao-Qing, FENG Ji-Kang
    1999, 20(2):  260-263. 
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    The equilibrium structures, relative stabilities of some isomers of substituted fullerene C58BN have been studied at the AM1, MNDO and INDO level. The results obtained by these semiempirical methods show that the substituted fullerene is less stable than C60. All the empirical methods in this work indicate that the 6-6 isomer is the most stable species for C58BN, and the stabilities decrease with the increasing of the distance between the heteroatoms. The small differences of ionization potentials between C58Band C60 indicate that C58BN may have similar chemical activity to react with nucleophiles, and the smaller ionization potentials indicate that C58BN may lose their electrons more readily. The eletronic spectra for some isomers of C58BN have been calculated by using INDO/CIS method.
    Further NMR Investigation and Conformation Study of Polypeptide IS4
    TU Guang-Zhong, MIAO Zhen-Wei, ZHANG Ri-Qing, LUO Xue-Chun JIANG Yun, ZHAO Nan-Ming
    1999, 20(2):  264-267. 
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    Two dimensional 1HNMR technique was used to determine the solution structure of IS4 The crosspeaks volumes in NOESY spectra were used to generate protonproton distance constraints. These data, combined with hydrogen bond constraints and angle constraints, were used to obtain a set of 10 structures by program DIANA. These structures were refined by unrestrained energy minimization using standard minimization program. The results indicated that the conformation of IS4 in CF3CD2ODis of helix.
    Electronic Structure and Biodegradability of Azo Dyestuff Molecule(Ⅱ) The Effect of the Nonlocalized Activity of Substituents on the Reduction Breakdown of Azobond
    ZHANG Xiao-Yi, LAN Wei, PAN Yu-Sheng, REN Da-Gong, DU Guo-You, DUAN Zheng-Kun, LIU Zhi-Chun, YAO Sha
    1999, 20(2):  268-271. 
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    The electronic effect of hydroxy, amino, nitro on the azobond was studied with nonlocalized activity of substitutents by means of MNDO calculated results and experimental results, then the electronic structure mechanisMAbout the effect of substitutents on the biodegradability was described, further, the QA(their values will reflect chemical activity of the atoms in the molecule) in MNDO statistical population analysis was regarded as an electronic structure parameter relating to the biodegradability of azobond.
    Hydrolysis and Structural Disintegration of MCM-41 Molecular Sieves
    LI Hui-Yun, SUN Yu, YUE Ying-Hong, GAO Zi
    1999, 20(2):  272-276. 
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    Hydrolysis and structural disintegration of SiMCM-41,AlMCM-41 and HAlMCM-41 under different conditions have been investigated. Pure SiMCM-41 exhibits a high thermal stability and hydrothermal stability when calcined in air and steam for a short period. Structural disintegration of SiMCM-41 has been observed after being exposed to moist air for 3 months, because the surface Si-O-Si bonds are split by hydrolysis forming hydrated silicic acid molecules. AlMCM-41 is more resistant to hydrolysis than SiMCM-41, but its high temperature stability in air and steam is limited by the presence of Na+ in its structure. HAlMCM-41 is more stable than AlMCM-41 during heat treatment. Salt effect during hydrothermal crystallization process has been proved to be the cause for the improvement of the stability of AlMCM-41 and HAlMCM-41 in moist air and hotwater. Hence, adding salt to the reaction mixture during hydrothermal crystallization can lead to a significant improvement of the water resistan.
    Theoretical Study of the Structures, Spectra and NonlinearSecondorder Optical Properties of SpiroconjugatedCompounds in Comparison with the CorrespondingPolyenes and Polyphenylslinked Compounds
    SUN Xiu-Yun, FENG Ji-Kang, REN Ai-Min, SUN Chia-Chung
    1999, 20(2):  277-280. 
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    Using the AM1 and INDO/CI methods, the structures and electronic spectra of spiroconjugated compounds(Ⅰ) have been studied. On the basis of the results above, according to the sumoverstates(SOS) formula, the nonlinear secondorder optical susceptibilities have been calculated. The results have been compared with those of the corresponding polyenes and polyphenylslinked compounds(Ⅱ) and (Ⅲ) calculated by using the same methods. The conclusion is that although the nonlinear secondorder optical susceptibilities βμ of spiroconjugated compounds(Ⅰ) are less than those of Ⅱand Ⅲ, the transparency is better than these of Ⅱand Ⅲ.
    Activation Energy of Micellar Catalysis on the Basic Hydrolysis of 2,4-Dinitrochlorobenzene
    ZHAO Zhen-Guo, JIAO Tian-Shu
    1999, 20(2):  281-285. 
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    The micellar catalysis of cetyl pyridine chloride(CPC) and cetyl trimethyl ammonium chloride(CTAC) on the basic hydrolysis of 2,4-dinitrochlorobenzene(DNCB) was investigated and the effect of adding butyl alcohol on the activation energy of the basic hydrolysis under micellar catalysis was calculated. The results show that: (1) The hydrolysis is catalyzed obviously by CPC and CTAC micelles; (2) Addition of small amount of t-C4H9OH en-hances the catalytic effect of CPC micelle; (3) The activation energy of the hydrolysis reaction in the solution of cationic micelles is 49 kJ·mol-1, which is much lower than the value of 91 kJ·mol-1 in water, implying a difference between the mechanisms of hydrolysis reaction in water and in micellar solutions.
    A Quadrupole Mass Spectrometric Study on Pulsed Laser Ablation of Y1Ba2Cu3O7-δ
    TANG Yong-Xin, DANG Hai-Jun, ZHANG Zhuang-Jian, QIN Qi-Zong
    1999, 20(2):  286-288. 
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    Pulsed laser ablation of Y1Ba2Cu3O7-δat 355 nm has been investigated with a quadrupole mass spectrometric technique. The profiles of the TOF spectra of Y, Ba and Cu atoms and ions are nearly the same. The translational energies of ionic ablated species estimated from their TOF spectra are independent on the laser fluences. The angular distributions can be well fitted by the expression of ccosnθ for ionic ablated Y+, Ba+and Cu+. The production of BaO, YO and CuO might have different mechanisms.
    A Study on O(1D)+CF3Br Reaction
    YU Yong, PAN Xun-Xi, LI Chao-Min, HOU Jian, HOU Hui-Qi
    1999, 20(2):  289-293. 
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    The mechanism of O(1D) reaction with CF3Br induced by photolysis of CF3BrO3systeMAt 253.7 nm was studied. The final reaction products are CF2O, F2and Br2. The rate coefficient of O(1D) reaction with CF3Br is obtained(k=1.3210-10 cm3molecule-1s-1). The possibility of O(3P) reaction with CF3Br and the influence of the added gases was also studied.
    Structural Features and Formation Kinetics of CnDm-Cluster Ions
    ZHOU Yi-Nan, CHEN Hong, TANG Zi-Chao, ZHANG Qiang, HUANG Rong-Bin, ZHENG Lan-Sun
    1999, 20(2):  294-296. 
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    By laser ablating of anthracene-d10sample, various CnDm-and Cn-cluster anions were generated. The distribution suggests that the structural configuration and stability of the clusters varied with the number of deuteriuMAtoms and the parity of number of carbons. With growing size of the clusters, their structural configuration changes from chain to monocycle, and further to polycycle. The analysis of the distribution also reveals the formation kinetics of the clusters.
    The Use of Solid State NMR in Structural Studies of AlON Spinel
    REN Hai-Lan, YUE Yong, YE Chao-Hui, DAI Ying, NAN Ce-Wen
    1999, 20(2):  297-298. 
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    27AlMAS NMR was used on structural studies of AlON spinel. The results suggested that NMR can offer more accurate information about microstructure and coordination when X-ray diffraction display the same spectra. The 27AlMAS NMR spectra of the samples of γ-AlON spinel crystal with different composition were acquired. The results confirmed that AlN4, AlO4 and AlO6structures exist in AlON spinel. The number of the nitrogen atoms that substitute oxygen atoms and enter into anion positions increases with the content of nitrogen increasing. However, the substitution has no influence on the structure of the crystal, thus no influence on the X-ray diffraction spectra.
    Structure and Property of Ionic Crosslinked Poly(vinyl chloride)
    BAO Yong-Zhong, HUANG Zhi-Ming, WENG Zhi-Xue, PAN Zu-Ren
    1999, 20(2):  299-303. 
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    PVCcontaining different contents of carboxylic group was synthesized by VC/AA suspension copolymerization and then ionic crosslinked PVC was prepared by solution and melting processing in the presence of metal salt. The structure and properties of ionic crosslinked PVCwere investigated. It was shown that carboxylic group in copolymer existed in dimer form, and was partially coordinated with metal cation after neutralization. VC/AA copolymer with higher AAcontent and neutralized with Ca2+, Mg2+cations tended to form thermalreversible ionic pair aggregation structure. The content and stability of ionic pair aggregation phase were affected by ionic pair content and type of metal cation. Tg, melting viscosity and elasticity of PVC increased as ionic crosslinking was introduced.
    Studies on Suspension Copolymerization Rate of Vinyl Chloride and N-Phenyl Maleimide
    DU Miao, WENG Zhi-Xue, SHAN Guo-Rong, HUANG Zhi-Ming, PAN Zu-Ren
    1999, 20(2):  304-308. 
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    The effects of monomer ratio, temperature and initiator concentration on the copolymerization rate of vinyl chloride(VC)/N-phenyl maleimide(PMI) were studied. The cross termination Φ and the reciprocal of the comprehensive rate δ2 were measured to be 5.77 and 53.65, respectively. The results showed that the copolymer composition of VC/PMI will largely change with the conversion. The activation energy of VC/PMI copolymerization and the propagation reaction are 127.9 kJ/mol and 63.7 kJ/mol, respectively. The order of initiator is 0.786. The reaction rates between VC/PMI and VC/N-cyclohexyl maleimide (CHMI) are compared, and the later is more rapid than the former.
    Electroluminescent and Displaying Devices Based on Semiconducting Polymers
    LI Xiao-Chang, SUN Jing-Zhi, MA Yu-Guang, SHEN Jia-Cong
    1999, 20(2):  309-314. 
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    This paper involves a review on the advancing history of electroluminescent and displaying devices based on semiconducting polymers(PLED), a series of main breakthroughs in this field in recent years. The different PLED structures and their features of nowaday ongoing research works are compared, the basic working principle of PLED are briefly introduced to the point, a precise defination of PLED quantum efficiency is given and the methods about how to improve the quantum efficiency are comprehensively described. The design, synthesis of charge transport polymers and their application in PLEDs are presented taking the prevalent multilayer PLEDs as examples. The application fields, existent problems, and future development of PLEDs are commented as a conclusion remark.
    Study and Preparation of Soluble Polypyrrole Composite Film
    WANG Chang-Song, ZHOU Ben-Lian
    1999, 20(2):  315-317. 
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    Through chemical oxidation method, pyrrole was polymerized in situ by FeCl3in PMMA matrix dissolved in ethyl acetate. The resulting polypyrrole was dissolved in PMMA solution. Asoft freestand composite film was produced by the evaporation of solvent ethyl acetate. Its conductivity(Py40% in mass fraction) was about 3S/cm measured by standard fourprobe method. It had a good stability in air. The factors affecting the polymerization such as temperature, time and matrix were investigated.
    Microcosmic Structure of Doped Polyaniline Synthesized by Emulsion Polymerization
    FENG Wei, WEI Wei, WU Hong-Cai
    1999, 20(2):  318-320. 
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    Using dodecylbenzene sulphonic acid(DBSA) as emulsifier and doping agent, polyaniline(PAn) emulsion was polymerized in a wateroil twophase system, a PAn with high solubility and conductivity was obtained. The structure of the product was studied by using XRD and TEM. The results showed that, the conductive PAn polymerized by this method displayed a higher crystallinity. Afibril micromorphology was observed by the transmission electron microscopy. The effect of macromolecular conformation of PAn on the absorption spectra was discussed.
    Copolymerization of Ethylene and Styrene Catalyzed via Supported Et(Ind)2ZrCl2
    YAN Wei-Dong, ZHANG Lei, ZHOU Nai, HONG Han, HU You-Liang
    1999, 20(2):  321-323. 
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    The poly(ethylenecostyrene) was synthesized with rac-Et(Ind)2ZrCl2/MAO supported on SiO2-955. Compared with homogeneous rac-Et(Ind)2ZrCl2/MAO, the content of styrene in the copolymer with the supported rac-Et(Ind)2ZrCl2/MAO was increased to 3.5%(molar fraction) and Al/Zr molar ratio was decreased to 300. The polymerization activity was 5.8×105g/(mol5h) at 353 K. The distribution of styrene unit in the copolymer was believed in randoMAccording to 13CNMR spectrum. The effects of Al/Zr molar ratio, the molar ratio of styrene to ethylene in the monomer feed and reaction temperature on the copolymerization were investigated in this paper.
    Crystallization Kinetics and Morphology of Poly(ether ester)/Montmorillonite Composite
    GU Qun, WU Da-Cheng, YI Guo-Zhen, ZHANG Guo-Yao, YANG Yu, WU Li-Heng
    1999, 20(2):  324-326. 
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    Poly(ether ester)/montmorillonite composites were prepared by transesterification polycondenzation based on dimethyl terephthlate, ethylene glycol, poly(ethylene glycol) (Mn=2000) and Namontmorillonite treated by cation exchange and surface modification. Their crystallization behavior and morphologies, in comparison with pure poly(ether ester), were studied by depolarized light intensity, DSC, polarizing optical micrograph, and SALS. When crystallization temperature Tcwas higher than 473K and the montmorillonite content was less than 1% the montmorillonite obviously increased crystallization rate of poly(ether ester), but the difference between them did not become apparent as Tc below 473 K. DSC cooling scanning curves showed that the peak temperature of the composite shifted to a higher temperature. By using CHCl3to get phase separation, poly(ether ester) and its composite showed spherulites and dendrites when Tc<473 K, but when Tc>473 K, both of them showed fourleafclover pattern. According to the experimental results we conclude that montmorillonite plays a role of nucleating agent in the matrix, but at the same time there is an interaction between poly(ether ester) and montmorillonite, which restricts the movement of chain segment and becomes more notable when Tcis lower and the content of montmorillonite is higher.
    Syndiospecific Polymerization of Styrene Catalyzed Using Polymer Supported CpTiCl3
    XU Jun-Ting, OUYANG Jian-Ying, FAN Zhi-Qiang, CHEN De-Quan, FENG Lin-Xian
    1999, 20(2):  327-329. 
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    CpTiCl3was supported on two kinds of styrene copolymer with different hydroxyl contents and polymerization behavior of styrene using the polymersupported catalysts was investigated. The supported catalysts show high activity and the percentage of butanoneinsoluble part of the polystyrene obtained is considerably high. The supported catalysts can catalyze styrene polymerization at lower Al/Ti ratio, lower catalyst concentration and higher temperature, the molecular weight of polystyrene is also enhanced. These indicate that polymer carrier can stabilize the active sites. This effect is more obviously observed when CpTiCl3is supported on polymer with higher hydroxyl content.
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