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Table of Content

    24 November 1998, Volume 19 Issue 11
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    Articles
    Nonaqueous Synthesis and Crystal Structure of NH4ZnPO4
    XU Jia-Ning, YUAN Hong-Ming, SHI Su-Hua, SUN Jian-Min, SONG Tian-You, FENG Shou-Hua, XU Ru-Ren, Bu Wei-Ming, Mao You-Gang, Ye Ling, Fan YU-Guo
    1998, 19(11):  1707-1710. 
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    Single crystal of NH4ZnPO4 was synthesized from nonaqueous system and its crystal structure was determined using single crystal X-ray diffraction. The structure was solved by direct method and refined by full-matrix least-square method. The crystal is hexagonal with space group P63 and has a unit cell with a =1.0688(2) nm, c =0.8706(2) nm, V =0.8613(2) nm3, Mr=17838, μ =59.65 cm-1, Z =8, Dc=2.751 g·cm-3, R =0.035, Rw=0.078. There are no Zn_O_Zn and P_O_Plinkages in the structure. Both zinc and phosphorus atoms are four-coordinated to oxygen atoms. The framework structure contains six membered ring direct channels along c-axis. The linear Zn_O_Plinkage was first found in the structure of the phosphates.
    A Study of the Intercalation Reactions of 4-(Methylmercapto)-aniline with α-Zirconium Phosphate
    DU Yi-Bo, LI Feng, HE Jing, David G. EVANS, DUAN Xue, WANG Zuo-Xin
    1998, 19(11):  1711-1714. 
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    Methylmercapto) aniline(MMA) has been intercalated into α Zr(HPO4)2·H2O(α-ZrP), and the characteristics of the intercalation reactions have been studied. Under mild conditions, no intercalation was observed. Under more forcing conditions, variable amounts of intercalation compound were observed along with unreacted α-ZrP. The yield of the intercalation compound is related to the ratio of MMA/ α-ZrP, the reaction temperature and intercalation method. The interlayer spacing of the intercalation compound is about 236 nm, and does not vary significantly with different preparation conditions. The molecules of MMAwhich have been intercalated into α-ZrPoccur in two forms, one being protonated, the other being unprotonated in the ratio of 1 to 11 respectively. This incomplete proton transfer may be related to the relatively low base strength of MMA.
    Synthesis,Crystal Structure and Properties of (Z)-3-Triphenylstannyl-1,1-diphenyl Propenol
    ZHU Dong-Sheng, FENG Su, ZHANG Li-Xin, FU Fang-Xin, Xing-Yan, Jia-Heng-Qing, Lin-Yong-Hua
    1998, 19(11):  1715-1718. 
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    Five new organotin compounds were synthesized and characterized. X-ray crystal structure analysis of (Z)-3-triphenylstannyl-1,1-diphenyl propenol was performed. The crystal belongs to space group P21 / n. The cell parameters are: a =1.2357(2) nm, b =0.9874(2) nm, c =2.2081(4) nm, β =95.23(3)°, V =2.6830(9) nm3, Z =4, R =0.0279, Rw=0.0645. The tin atom of the molecule exists in a distorted tetrahedron, Zisomer of double bond is obtained.
    The Preparation of Cubic C3N4 by Pulsed-laser Inducing Reaction on Liquid-solid Interface
    WANG Jin-Bin, LIU Qiu-Xiang, YANG Guo-Wei
    1998, 19(11):  1719-1720. 
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    Cubic C3N4 has been produced by pulsed-laser inducing the reaction on ammonia solution graphite interface at the first time. Transmission electron microscopy(TEM) and high resolution electron microscopy(HREM) are used to characterize the structure of the cubic C3N4. The TEMimage of cubic C3N4 has been provided, and the graphite lattice, the theoretical cubic C3N4 lattice and the experimental lattice of the interplanar spacings have been compared with one another.
    Synthesis of Lyotropic Liquid Crystals by Heteropoly Compounds Derivatives
    HUANG Ru-Dan, FEI Bao-Li, WANG En-Bo, LI Bai-Tao, ZHANG Su-Xia
    1998, 19(11):  1721-1723. 
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    Heteropoly compound, Na16 P4W30Cu4(H2O)2O112 · n H2O, has been transferred from water to benzene by phase transfer. After the surface coordinated water molecule was removed and title compound is substituted by pyridine, we get a lyotropic liquid crystal formed by heteropolycompound and small molecule formed by organic basis. It is characterized by polarimicroscope, DSCand heterothermal as well as wide angle X-ray diffraction.
    Influence of Structure of Diamides on the Extractive Properties of Eu(Ⅲ)and Am(Ⅲ)
    CHEN Wen-Jun, ZHU Lin, DING Song-Dong, LIU Zhong-Qun, CHEN Sao-Jin, JIN Yong-Dong
    1998, 19(11):  1724-1726. 
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    The solvent extraction behavior of the diamides, (R1R2NCO)2R3 for Eu 3+ and Am 3+ has been examined.
    Mechanism and Structure Analysis of TiO2 Surface Coated with SiO2 and Al2O3
    CUI Ai-Li, WANG Ting-Jie, JIN Yong, XIAO Shuai-Gang, GE Xu-Dong
    1998, 19(11):  1727-1729. 
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    Photochemical activity of TiO2 can be reduced through surface coating, which favors to increase dispersiveness, weather resistance and antipulverization. The binary coating process of Si and Al to TiO2 was studied experimentally. The isoelectic point of TiO2 in seriflux was measured as pH was equal to 36. Maximum Zeta potential can be got at pH 10 around, which favors to dispersion of particles. Studies on the aggregation rate of Si and Al indicate that, when pHhas a value between 9 and 10, the aggregation rate of silicon acid is small, which favors to form homogeneous and compact membrane, so optimal coating pHvalue is between 9 and 10. According to the difference of 2 p orbital electron binding energy of Ti in XPS before and after being coated, it can be inferred that Si and Al in coating layer combine to TiO2 surface through chemical bond.
    Studies on Drugs Absorption Using Liposome to Simulate Biomembrane
    LUO Yun-Jing, SHEN Han-Xi, LIU Hai-Tao, KONG De-Ming
    1998, 19(11):  1730-1734. 
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    The absorptions of liposoluble salicylic acid, water soluble vitamin B6, ceftriaxone, quinolone antibacteria norfloxacin and anticancer medicine doxorubicin were discussed by using liposome as biomembrane model and comparison with cell membrane. The absorption of salicylic acid whose absorption curve is linear depends on the passive diffusion. The experimental result of vitamin B6 supports the opinion that the absorption of vitam in B6 depends on proteins which lie in membranes. The absorption of vitamin B6 is a chemical process, so absorption curve is nonlinear. The absorption mode of ceftriaxone is a simple diffusion. The absorption of norfloxacin depends on the effects of metal ions. Under the driving force of nucleic acid in cells, doxorubicin was absorbed through biomembrane.
    Detection of Specific Noncovalent Protein-fullerenols Complexes by Matrix-assisted Laser Desorption Ionization Mass Spectrometry
    SHE Yi-Min, JI Yi-Ping, HE Yu-Fan, LIU Shu-Ying
    1998, 19(11):  1735-1738. 
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    Matrix assisted laser desorption ionization(MALDI) mass spectrometry is difficult for the characterization of noncovalent complexes hitherto because of the limitations in acidic matrix, sample preparation, laser induced polymerization and adduct formation with matrix. Under our experimental conditions, sinapinic acid is used as a matrix, the specific noncovalent interactions of protein with fullerenols were observed by MALDImass spectrometry. Some mass spectrometric features, such as mass shifts, broad adduct peaks and stoichiometries, showed that the specific non covalent complexes between protein and fullerenols have been formed at a ratio of 1:4 for hemoglobin fullerenols or 1:1 for myoglobin fullerenols. The results implied that fullereneols could be used to protect partly hemoglobin from decomposition in acidic media, and therefore, it is possible to realize the molecular weight determination of a quaternary protein by MALDImass spectrometry via the addition of specific organic compound in the matrix.
    Studies on Microwave Plasma Torch Atomic Emission Detector and Its Response Characteristics for Gas Chromatography
    SHI Yu-Hua, YANG Wen-Jun, YU Ai-Min, CAO Yan-Bo, JIN Qin-Han
    1998, 19(11):  1739-1742. 
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    The present paper deals with a microwave plasma torch atomic emission detector for gas chromatography, argon was used as the carrier and support gas, oxygen as scavenger and sheath gas, respectively. The response characteristics of the MPT AEDfor carbon in organic compounds was studied. The effect of oxygen sheathing on the detection performance for carbon was discussed.
    Development and Application of Polyvinyl Chloride Modified Powder Microelectrode
    YANG Tian-Ming, HU Xiao-An, LU Jian-Jie, DENG Min
    1998, 19(11):  1743-1745. 
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    Polyvinyl chloride film powder microelectrode, which is prepared by flow spread over the powder microelectrode with the tetrahydrofuran solution of 1.5% PVCand 1% di iso octyl phthalate. When this PVCfilm is swollen in solution, it has permeability and selectivity for the substance of electrochemical activity. Cyclic voltammetry of polyvinyl chloride modified powder microelectrode in 10mmol/L K3Fe(CN) 6+1 mol/L KCl solution, the results show that this is semi reversible electrode process. When the scan rate of potential come up, Δ Ep increased, ipa / ipc becomes less and verge to 1. EK3Fe(CN)6/K4Fe(CN)60' was calculated with Epa and Epc to be +0.167 V(vs. SCE), which agreed with the standard value. This PVCfilm electrode exhibit fast response and long term stability, allowable operating potential range(potential range: +1.2～-1.2 V) and no use for mercury. It is used for work electrode in the stripping voltammetry under no strirring. In a supporting electrolyte of 0.02 mol/L HAc, anodic stripping voltammetry(ASV) for the direct determination of Pb 2+ in tap water. For tap water a mean value of 105×10-7 g/mL Pb 2+ was found, which agreed with the method of the hanging mercury drop electrode(HMDE). The relative standard deviation(n =5) for Pb 2+ is 1.3%. Recoveries of Pb 2+ in water samples are between 97.8% and 99.5%.
    Determination of Ni,Cu and Hg by Flow Injection Preconcentration Coupled with HPLC
    Akbar Ali, SHEN Hong, XU Guang-Ming, YIN Xue-Feng
    1998, 19(11):  1746-1748. 
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    Ahome designed pressure tight preconcentration column combined with the HPLCsix-port valve was used to interface the FIsorbent extraction preconcentration system and HPLC. Based on this system, a method for determination of trace amount of Ni, Cu and Hg in water samples after on-line derivatization and preconcentration as their diethyldithiocarbamate complexes has been developed. The sensitivity and selectivity can be further improved by using time programming for absorption measurement. The detection limit 0.16 μg/L, 0.41 μg/Land 1.1 μg/L, and the relativity standard deviation, 3.6%, 4.5% and 3.9%, were found for Ni(Ⅱ), Cu(Ⅱ) and Hg(Ⅱ), respectively.
    Electrochemical Behavior of 3,4-Dihydroxybenzoic Acid in Self-Assembled Monolayer Electrode System
    ZHAO Jian-Wei, NIU Li, DONG Shao-Jun
    1998, 19(11):  1749-1751. 
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    The self assembled monolayer of cystamine was prepared on gold electrode and 3,4-dihydroxybenzoic acid(DHBA) was electrochemically deposited on cystamine surface as a functional group by electrostatic adsorption, namely, molecular deposition. It shows that the MD/SAMstructure has a higher stability, and E1/2 of the DBAHin MD/SAMshifts more negative than that of on naked gold electrode. The n-decanethiol was also used to fill defects in MD/SAM, it results in much better cyclic voltermmetric behavior.
    Effect of AIcohol Modifier on Micellar Electrokinetic Chromatography Separation
    LU Jian-De, XU Xiu-Zhu, FU Xiao-Yun
    1998, 19(11):  1752-1754. 
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    The effect of the addition of normal C1—C5 alcohols on the background electrolyte on the separation of a set of wide polar aromatic hydrocarbons in micellar electrokinetic capillary chromatography(MECC) was examined. Experiments were carried out with the micellar solution system of sodium dodecyl sulfate borate at pH 9.2, containing different amount(0—15%) of C1—C5 alcohols separately. For the shorter alkyl chain C1—C3 alcohols, as the content of alcohol increased, the elution window(tm/t0) increased, and the capacity factors(k') of all test samples decreased. Comparatively, C4 and C5 alcohols had the different effects. With the content increased the tm/ t0 increased first and then decreased, and the k' increased for the most solutes. The results also showed that the alcohol additives had more effect on weakly polar or hydrophobic compounds than more polar compounds. The addition of alcohol caused the increase of both the number of theoritical plates(N) and the resolution, especially for the hydrophobic compounds.
    Direct Enantiomeric Resolution of Eight Kinds of Thio-glycidyl Ether Using Amylose-chiral Stationary Phase by HPLC
    ZHOU Zhi-Qiang, DING Er-Run, HU Yu-Lai, YU Zhao-Wen, CHEN Li-Ren
    1998, 19(11):  1755-1757. 
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    In the present study, amylose-tris(phenylcarbamate)(ATPC) and amylose-tris(3,5-dimethylphenylcarbamate)(ADMPC) were synthesized, and used as the chiral stationary phases upon adsorption over silica gel. These stationary phases offered a practically useful chiral column with a high enantiomer-separability. Amylose was allowed to react with an excess of phenylisocyanate or 3,5-dimethylphenylisocyanate in pyridine for 48 h. The carbamates obtained were 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 eight thio-glycidyl ethers were resolved on the two chiral stationary phases. Separation was carried out with a hexane/2-propanol mixture at a flow rate of 1.0 mL/min at room temperature. The effects of chiral stationary phases and 2-propanol concentration on the retention and resolution were investigated.
    Studies on the Solution Conformation of Angiotensin Ⅱ
    WANG Rui, HU Xiao-Yu, MA Ya-Ping, Li Du
    1998, 19(11):  1758-1762. 
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    Human angiotensin (AngⅡ) was obtained by solid phase method. Its solution conformations in D2Oand DMSOd6 were examined by 2D NMRtechnique. The dihedral angle constraint, distance constraint, hydrogen bond constraint were made based on coupling constants, ROE effect, temperature coefficient of chemical shifts. It is concluded that Ang Ⅱ exists in D2Oand DMSOd6 as closed similar conformations that is random coil with negligible content of α helix, 310 helix, β turns, γ turns, parallel and antiparallel β sheet. The conformation in D2Owas not sensitive to temperature.
    Studies on the Chiral Structure of Thiazolidine Ligands and Their Application to Asymmetric Hydrosllylation Of Acetophenone
    YAO Jin-Shui, XU Gui-Yun, Li Hong, He Bing-Lin
    1998, 19(11):  1763-1766. 
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    The structure and optical activity of two thiazolidine ligands, 2-(2-pyridyl)-4-carbomethoxy-1,3-thiazolidine(A) and 2-methyl-2-(2-pyridyl)-4-carbomethoxy-1,3-thiazolidine(B), were reported in this paper. The diastereomers of Aand Bwere purified by fractional crystallization or column chromatography. The asymmetric hydrosilylation of acetophenone catalyzed by in situ catalysts prepared from Rh(COD)Cl2 and ligand Aor Bwas investigated respectively. It was found that the cataytic reaction was only influenced by the chiral structure of C4 in thiazolidine, the chiral centre of C2 epimerized rapidly catalyzed by Rh(Ⅰ).
    Conformational Studies on 2-(4-Aminocarbonyl-2-thiazoyl)-1,4-anhydro-L-xylitols and Their Fluorine Derivatives
    ZHANG Hu-Yi, ZHANG Liang-Ren, MA Ling-Tai, ZHANG Li-He, CUI Yu-Xin, LIU Xue-Hui
    1998, 19(11):  1767-1770. 
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    Employing computer aided molecule simulation, the conformations of 2-(4-aminocarbonyl-2-thiazoyl)-1,4-anhydro Lxylitols and their fluorine derivatives have been studied. The results obtained from calculation show that these novel isomeric Cnucleosides favor the Sconformation. NMRstudy and crystal X-ray analysis of these compounds coincidentally point to Stype furanose conformation.
    Synthesis and Reaction of α-Thiocarbonylthioformmorpholine
    ZOU Jian-Ping, ZENG Run-Sheng, WANG Ai-Fen, LU Zhong-E
    1998, 19(11):  1771-1773. 
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    α Thiocarbonylthioformmorpholines(2a_2c) have been synthesized. Compound 2a can react with o-diaminobenzene, aminourea and phenylacetylene to yield the corresponding products 2-morpholino-3-phenylquinoxaline(3) and 5-morpholino-6-phenyl-1,2,4-triazine-3 one(4) and 2,4-diphenyl-3-morpholino thiophene(6), respectively.
    Synthesis and Crystal Structure of 1,1,4,4-Tetrachloro-1a,3-diphenyl-1a,2,3,4-tetrahydro-1H-Azirino[2,1-e][1,6]benzothiazocine
    XU Jia-Xi, LAN Ruo-Xi, JIN Sheng
    1998, 19(11):  1774-1776. 
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    Title compound was synthesized by insertion and cycloaddition reaction of 2,4-diphenyl-2,3-dihydro-1,5-benzothiazepine and dichlorocarbene generated from chloroform under the alkaline condition and its crystal structure was determined by X-ray diffraction method. The single crystals belong to orthogonal, space group Pc21 /n with a = 1.0243(2) nm, b = 1.1451(2) nm, c = 1.8388(3) nm, V = 2. 1570(5) nm3, Z =4, Dc=1.693 g·cm-3, μ =0.066 mm-1, F (000)= 1066 for 2467 reflections, R =0.039, Rw=0.054.
    Preparation and Evaluation of Polybutadiene Encapsulated HPLC Packing Material by у-Radiation Crosslinking
    QI Jian-Ping, ZUO Yu-Min, XU Xiao-Wen, CHEN Yi-Hui, CHEN Fan-Xin, WANG Yong-Qiang
    1998, 19(11):  1777-1779. 
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    Polybutadiene oligomer was encapsulated on specially presilanized silica particles by γ-radiation crosslinking and by addition of a definite amount of tripropylene glycol diacrylate or ethylene dimethacrylate as enhancement reagent. The effects of kind and content of the enhancement reagent and radiation dose on the crosslinking products are discussed. The elemental analysis results, scanning electron micrograph and diffuse reflectance infrared spectra were proof that the preparing process is successful. Such material is easy to pack and yields high efficiencies. Its supper performance for the separation mixtures of aromatic hydrocarbons, alkyl benzenes and amino-containing compounds are demonstrated by practical examples.
    Studies on Bio-rational Design of Photosystem Ⅱ Inhibitors(Ⅲ),——Comparative Molecular Field Analysis of 3-(4-Chlorobenzylamino)-2-cyano-3-alkylacrylate Inhibitors
    LIU Hua-Yin, LU Rong-Jian, YANG Hua-Zheng, LAI Lu-Hua
    1998, 19(11):  1780-1782. 
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    Comparative molecular field analysis of 3-(4-cholorbenzylamino)-2-cyano 3-alkyl-acrylate inhibitors was studied. It was found that the side chain of ester might be a Hbond binding area, and the stereo character of 3-alkyl is important for bioactivity of compounds.
    Theoretical Study on the Electronic Structures of C120 O-and C120 O2-
    TIAN Wei-Quan, FENG Ji-Kang, REN Ai-Min, GE Mao-Fa, HUANG Xu-Ri, LI Zhi-Ru, SUN Jia-Zhong
    1998, 19(11):  1783-1788. 
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    The electronic structures of ions C120 O- and C120 O2- of C120 Owere investigated with INDOseries methods. The results suggested that the negative charge of C120 O- and C120 O2- distributed equivalently over the two C60 cages and there was a weak interaction between the two cages in those ions. The ground state of C120 O2- is triplet.
    The MO Interaction in (Dithiophene[3,2-b:3',2'-d] cyclopentan-4-ylidene)fullerene[60]and Its Electronic Spectrum and Second-order Optical Property
    SUN Xiu-Yun, FENG Ji-Kang, TIAN Wei-Quan, REN Ai-Min, GE Mao-Fa, SUN Jia-Zhong
    1998, 19(11):  1789-1793. 
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    On the basis of ZINDOmethods, according to the Sum-Over-States (SOS) formula, the program for the calculation of second-order optical susceptibility β has been devised. The MOinteraction in (dithiophene 3,2-b:3',2'-d cyclopentan-4-ylidene)fullerene 60 has been studied, moreover, the electronic spectrum and second-order optical susceptibility of this molecule have been calculated. The former is in good accordence with the experimental result, and the latter is a theoretical prediction.
    Fourier Transform Infrared Photoacoustic Spectroscopy of Tetra(para-octanoyloxyphenyl)Porphyrin Complexes
    SHI Tong-Shun, LIU Wei, WANG Yin-Jie, ZHAO Jun, LIU Guo-Fa
    1998, 19(11):  1794-1798. 
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    The fourier transform infrared photoacoustic spectra of tetra-(para octanoyloxyphenyl) porphyrin T(p-OO)PPH2 and its Mn(Ⅲ), Fe(Ⅲ), Co(Ⅱ), Ni(Ⅱ), Cu(Ⅱ) and Zn(Ⅱ) complexes in the range of 3600～190 cm-1 were measured and investigated. The bands at 3318.0 and 968.0 cm-1 of T(p-OO)PPH2 are due to the N—Hstretching and in plane and out-plane bending vibration of the pyrrole groups. All these bands disappear upon complexes formation. The vibration coupling between the M—N stretching and the porphyrin ring deformation appears at 243 cm-1. Metal sensitive bands were found at 1504, 1350, 1022, 995, 796 and 235 cm-1.
    Theoretical Model and Method for Pollutant Distribution in Water
    ZHAO Bao-Zhong, CHU Bei, SU Zhong-Min, WANG Rong-Shun
    1998, 19(11):  1799-1802. 
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    Atheoretical model was found for pollutant distribution in the natural water body, and the mathematical equation was obtained from the model by physical chemistry principal for calculating the distribution of pollutants in water. The relative distribution values(PN) were calculated with MNDOmethod for seven organic pollutants, and the calculated PN is accorded with the distribution coefficients of octagonal-water for the benzene halides.
    Time Variable Method of Thermokinetics——Chemical Reactions with Simple Order
    ZENG Xian-Cheng, CHEN Yong, WANG Qian, MENG Xiang-Guang, QIN Zi-Ming
    1998, 19(11):  1803-1806. 
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    On the theoretical basis of thermokinetics proposed in previous articles, a novel thermokinetic research method——time variable method, has been proposed in this paper. The method only needs three time points ti, peak height Δi at ti and peak area ai before time ti. It does not require the thermokinetic reaction to be completed. The rate constants were obtained by data processing on computer. In order to test the correctness of the method, first-order reaction, second-order reactions(with equal concentrations and unequal concentrations, respectively), third-order reaction, 1.5-order reaction have been studied. The rate constants are quite in agreement with those in literature. Time variable method is believed to be correct.
    Diffusion Behavior of Ethanol in Epoxy/Urethane Acrylate Resin Interpenetrating Polymer Networks(Ⅰ)——Homogeneous Transport Model and Correlation with Experimental Sorption Curves
    HUA Feng-Jun, LI Jun, HU Chun-Pu, LIU Hong-Lai, HU Ying
    1998, 19(11):  1807-1812. 
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    A transport-complex model has been established to correlate the experimental absorption curves of epoxy resin(epoxy) and urethane acrylate resin(UAR) simultaneous interpenetrating networks(SINs)with ethanol as the diffusion agent. The experimental results show that the simulative curves calculated can be correlated by using the complex model well enough with the experimental data in general and the physical meaning of correlating coefficient ωr is expressed as the ability of migration of ethanol through the networks after it makes hydrogen bond with urethane, ester or ether groups existing in the networks. Consequently it directly responds to the structures and morphologies of the SINs. The parameters measured including the solubility constant S, average diffusion coefficient Dand penetrating weight Pare all related to the composition of such SINs. It clearly exhibits that ethanol mainly transports through the UARphase.
    A Theoretical Study of Solvent Effects on Tautomeric Equilibrium of 2,6-Dimercaptopyridine
    ZOU Jian-Wei, YU Qing-Sen, ZHU Long-Guan
    1998, 19(11):  1813-1816. 
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    In the present paper, ab initio calculations have been performed for the thione-thiol tautomeric equilibrium of 2,6-dimercaptopyridine in the gas phase and in different solutions at HF/6-31G ** level. The solvent effects on the tautomeric equilibrium are investigated Onsager self-consistent reaction field(SCRF) model. The results obtained show that the dielectric media have more significant effects on the molecular geometry of the thione tautomer than on that of the thiol tautomer, and the calculated tautomerism energies predict the thiol tautomer to be dominant in the gas phase and in solvents of low dielectric constant, however, owing to the strong polarization effects, in solvents of high dielectric constant, the tautomeric equilibrium is shift in favor of the more polar thione form, which are in agreement with experiment.
    Stochastic Simulation of Master Equation for Chemical Chaos
    WANG Hong-Li, LI Qian-Shu
    1998, 19(11):  1817-1819. 
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    The underlying master equation for the chemical Lorenz system was examined in this paper. Ensemble simulation investigations show that in the chaotic regime the mass action description was related neither to the ensemble mean nor to the most probable values. These indicate that in the chaotic regime, the phenomenological description is no longer useful snd cannot be justified from the underlying mesoscopic description.
    Intrinsic Molecular Fluctuations in Chemical Lorenz System
    WANG Hong-Li, LI Qian-Shu
    1998, 19(11):  1820-1822. 
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    In the framework of stochastic theory of chemical reactions, we examined the master equation for the chemical Lorenz system. Directd simulatation studies show that in the chaotic regime the mass action kinetics at the macroscopic level no longer provide a correct collective description of the underlying reaction processes. These results indicate that a microscopic or at least mesoscopic description is necessary in this circumstance.
    Bimetallic Synergic Effect in the Selective Catalytic Hydrogenation of Cinnamaldehyde
    ZHANG Yuan-Kui, LIAO Shi-Jian, XU Yun, YU Dao-Rong, JU Shang-Yu, GUAN Zhi-Xia
    1998, 19(11):  1823-1825. 
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    The bimetallic catalysts, PdCl20.5 MY-PPh3 MY=NiCl2, Ni(OAc)2, Fe(acac)3, Co(OAc)2, Co(acac)2 or CoCl2 reduced by NaBH4, exhibit much higher selectivity in comparison with that of the monometallic Pa catalyst in the selective hydrogenation of cinnamaldehyde to 3-phenylpropanal at 66 ℃ under atmospheric pressure. Astrong synergic effect occurs between Pd and the second metal component for the high selectivity. Among these catalysts, PdCl2-0.5Co(OAc)2-PPh3 reduced by NaBH4 is the best catalyst.
    Structure and Luminescent Properties of YAG:Eu,Bi Synthesized by Sol-Gel Method
    ZHOU Shi-Hong, ZHANG Si-Yuan, ZHANG Jing-Jun, PENG Wen-Ge
    1998, 19(11):  1826-1828. 
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    (Y1- x-y Eux)3Al5O12 and (Y1- x-y EuxBiy)3Al5O12 were prepared by sol gel method. Their structures of the luminophor are similar to that of YAG, which is recorded on the ASTMcard and belongs to a cubic system. The luminescent properties show that the reaction temperature of the current sol gel method is in the range of 400500 ℃, which is lower than that of the conventional solid state reaction. The luminophors have the strongest emission intensity when the values of x and y are 0.06 and 0.013, respectively.
    Studies of Vitamin K by Pulse Radiolysis and Laser Photolysis(Ⅱ)——Time-resolved Studies of Oxidation Reactions of VK3 in Aqueous Solution
    CHEN Jia-Fu, CHU Gao-Sheng, GE Xue-Wu, ZHANG Zhi-Cheng, YAO Si-De
    1998, 19(11):  1829-1831. 
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    The mechanisms of reactions between OH, SO4-· and VK3 in aqueous solution have been investigated by using pulse radiolytical dynamic absorption spectroscopy. While VK3 reacts with ·OHand SO4-· respectively, the formation of dehydrogenated radical of VK3 with characteristic absorption peak round 400 nm has been observed, this is also confirmed by the results of laser photolysis of VK3 in aqueous solution.
    Studies on Properties of Epoxy Resin Toughed by a Funetionalized Polymer Containing Liquid Crystalline Unit
    ZHANG Bao-Long, TANG Guang-Liang, SHI Ke-Yu, YOU Ying-Cai, DU Zong-Jie, YANG Jian-Feng, HUANG Ji-Fu
    1998, 19(11):  1832-1836. 
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    Aseries of reactive toughening accelerators(LCEUPEG) containing both the flexible chain and rigid chain liquid crystal unit were synthesized and used to toughen the epoxy resin/dicyandiamide curing system. The curing reactivity, relationships of dynamic mechanical properties and impact strengths with the amount of LCEUPEGof the modified systems were investigated. The results showed that impact strength of the modified systems was enhanced for 3～7 times compared with the unmodified system, the modulus of the modified systems were also higher than that of the unmodified curing system.
    Use of Chain-Extended Ureas as Latent Curing Agents and Toughening Modifiers for Epoxy Resin
    ZHANG Bao-Long, ZHANG Hui-Qi, YOU Ying-Cai, DU Zong-Jie, DING Pei-Yuan, ZHAI Hua-Chun, HUANG Ji-Fu
    1998, 19(11):  1837-1839. 
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    Aseries of chain-extended ureas(Ui) containing polyethylene glycol (PEG) flexible spacers were synthesized and the reactive activity, the storage property, dynamic mechanical behavior and impact strength of the epoxy resin/Ui/ dibenzyl amine(DBA) system were studied. The results showed that the storage life of the epoxy resin/Ui/DBAsystem could be delayed to 40 h at 323 Kand the impact strength of the epoxy resin/chain-extended urea containing PEGspacer with molecular weight 600/DBAsystem was about five times higher than that of the epoxy resin/urea without PEGspacer(UO)/DBAsystem.
    Molecule Design and Syntheses of Optical Resins with High Refractive Index(Ⅲ)——Synthesis of MMDMA and Preparation of Its Copolymer Resins
    GAO Chang-You, YANG Bai, SHEN Jia-Cong
    1998, 19(11):  1840-1843. 
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    Mercaptomethyl-1,4-dithiane(MMD) and 2-methacrylthiomethyl-1,4-dithiane(MMDMA) were synthesized through hydrochloride/thiourea method and special Phase Transfer Catalysis (dropping caustic solution) at low temperature, respectively. The ring rearrangements of MMDin the synthesis process and the copolymerization property of MMDMAwere discussed separately, thus a new kind optical resins with high refractive index and low chromatic dispersion were obtaind.
    Molecular Design of Novel Metallocene Catalysts and Styrene Syndiospecific Polymerization
    ZHU Fang-Ming, LIN Shang-An, ZHOU Wen-Le, TU Jian-Jun, CHEN De-Quan
    1998, 19(11):  1844-1847. 
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    CpTiCl3, Cp*TiCl3, Cp*Ti(OMe)3 and Cp*Ti(OCH2CHCH2)3 were compared as styrene syndiospecific polymerization catalysts activated with methylaluminoxane(MAO) in toluene solution. G5-pentamethylcyclopentadienyltriallyloxy titanium Cp*Ti(OCH2CHCH2)3 /MAOis a highly active catalyst for styrene syndiospecific polymerization at 333～363 K. The influence factors of polymerization temperature and time, catalyst and styrene concentration on styrene polymerization have been studied. When the total polymerization product was extracted with boling butanone for 8 h, the insoluble fraction is over 98.7%. The syndiotactic polystyrene(sPS) obtained by extraction has high molecular weight(Mv=4.15×105～2.46×105) and high melting temperature(542.5～543 K) determined by DSC.
    Stability of Emulsifier-free Emulsion Copolymerization of MMA/BA/Comonomer with Two Functional Groups
    ZHANG Mao-Gen, WENG Zhi-Xue, HUANG Zhi-Ming, MAO Xin, PAN Zu-Ren
    1998, 19(11):  1848-1852. 
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    Aseries of functional comonomers with anionic and nonionic hydrophilic groups, sodium glycol maleate(SGM, or I-1) and sodium polyethylene glycol maleate (SPEGM, or I-2, I-4 and I-6) made from polyethylene glycol PEG200, PEG400 and PEG600, were synthesized and used in MMA/BAemulsifier-free emulsion copolymerization. The effects of the spatial effect, concentration and feeding mode of comonomer on the stability of the emulsifier-free latexes(EFL) were investigated. The stable and almost monodispersed EFLcan be obtained with appropriate comonomer and semicontinuous feeding mode. Coagulum in the emulsifier-free emulsion polymerization system was formed mainly by destabilizing coagulation mechanism owing to insufficient protecting groups on particles and by bridging coagulation mechanism caused by water-soluble homopolymer of comonomers or copolymers enriched with such comonomers.
    An Investigation of the Surface Modification Mechanism on PET by Fluorocarbon Piasmas
    ZHANG Liang, FAN Xiao-Ping, Wang Jian-Qi
    1998, 19(11):  1853-1856. 
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    Poly(ethyl terephthalate)(PET) surfaces were modified by CF4 and CH4/CF4 plasmas in this paper. The angle-dependent X-ray photoelectron spectroscopy(XPS) technique was employed to determine the changes of surface structures and properties of the modified PET. The surface modification mechanisms on PETby the fluorocarbon plasmas at different molar ratios were detailed discussed. Experimental results show that hydrophobic characteristic of the modified PETsurface can be improved by fluorocarbon plasmas singnificantly. CH4/CF4 mixture plasma is polymerization predominated, and the homogeneity along depth of surface layers can be intuitively observed. On the other hand, pure CF4 plasma is etching prodominated, and the fluorine-containing groups distributes on the modified PETsurface.
    Studies on Phase Morphology Control of Epoxy/PSF Blends
    SUN Jia-Ning, XIE Xu-Ming
    1998, 19(11):  1857-1860. 
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    Effective ways to control the phase morphology of the epoxy(E51)/PSF/DDSblends were studied. Scanning electron microscopy(SEM) and FTIRresults revealed that epoxy resins with different molecular weight were formed by changing the degree of precure conversion, and the later cure would result in phase morphology with different average size of epoxy particles. The cure process to effectively control the phase morphology of epoxy blends could be made according to the FTIRresults. Boron trifluo ride-ethylamine complex(BTF-EA) was effective to accelerate the cure reaction of epoxy resin with DDS. The rise in cure reaction speed induced the phase structure with smaller domain size. This could be explained by the quick formation of crosslinking network that locked in the phase separation at the earlier stage in the system.
    Synthesis of Nitric Oxide Traps α,ω-Bis(imidazoline nitronyl nitroxide)phenyl Polyethers
    SUN Xiang-Yu, HUANG Yu-Mei, ZHAO Yao-Xing, SUN Jian, LU Dao-Hui
    1998, 19(11):  1861-1863. 
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    Aseries of NOtraps with two trapping centers bridging by polyether α,ω-bis(imidazoline nitronyl nitroxide) phenyl polyether have been designed and synthesized. Their physical properties and the characteristics of the spectra have been examined. Under different solvent systems, the title compounds can trap NOreleased from sodium nitroprusside by photolysis forming the corresponding imino nitroxides, which were characterized by means of electron spin resonance.
    Studies on the Effects of the Third Phase on the Coarsening of Incompatible Polymer Blends
    XIE Xu-Ming, XIAO Tian-Jing, YANG Yong
    1998, 19(11):  1864-1866. 
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    In this study, phase contrast microscope and computer image analyzer were used to study the coarsening process of the dispersed phase of the polymer blend (PP/EVAc) under 2 dimensional and 3 dimensional conditions. The results showed that under 3-dimensional condition, the growth of the dispersed phase follows r3～t1.01, corresponding to the evaporation condensation theory of LifshitzSlyozov——r3～t, while under 2-dimensional condition the growth law is r3～t1.32. The growth speed of the dispersed droplets under 2-dimensional condition is faster than that under 3-dimensional condition. This difference is caused by the wetting effects between the third phase and polymer blend.
    Studies on Photoconductivity of TiOPc-NiPc Composite
    ZHANG Cheng, PAN Pu-Dun, WANG Mang
    1998, 19(11):  1867-1868. 
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    The xerographic properties of negatively charged dual layer photoreceptor(P/R), where TiOPc and NiPcomposite as the charge generation material(CGM), and 4-dimethy laminobenzaldyhyde-diphenylhydrazone(DMPH) as the charge transportation material(CTM), have been studied. In these composites, polymorphic transformation occurs and an increased photoconductivity is observed compared with its maximum values of the pure being w (TiOPc)=75%.
    Synthesis and Characterization of Polyazodiphenylene Phenylphosphonates
    TANG Xu-Dong, CHEN Xiao-Ting, WANG Yu-Zhong, YANG Ke-Ke, WU Da-Cheng
    1998, 19(11):  1869-1871. 
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    Anew polyazophosphonate, polyazodiphenylene phenylphosphonate(PAPPP) was obtained by the interfacial polycondensation of phenylphosphonic dichloride with 4,4-dihydroxyazobenzene. The structure of the polymer was confirmed by FTIR, 1H NMR, 31 P NMRand elemental analysis. The thermal behavior was evaluated by DSCand TG, the high residue of PAPPPis due to the presence of nitrogen and phosphorus in the same mainchain. Nitrogen appears to have a somewhat synergistic flame retardant effect with phosphorus. PETsamples containing 5% and 10%(mass ratio) PAPPPhave limiting oxygen index values of 28.2 and 33.4. It may be concluded that nitrogen containing polyphosphonate possesses superior flame retardancy.
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