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CJCU

Table of Content

    24 October 1997, Volume 18 Issue 10
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    Articles
    A Study of Thermodynamic in Axial Coordination Reaction of Unsymmetrical Derivatives of Tetraphenylporphyrinatpcobalt(Ⅱ)
    SHAO Ying, ZHU Zhi-Aug, RUAN Wen-Juan, YANG Shao-Ying, TIAN Jian-Hua, MA Gang, ZHANG Zhi-Hui, CHEN Rong-Ti
    1997, 18(10):  1571-1575. 
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    5-(4-Acetamidophenyl)-10,15, 20-tris (4-methylphenyl) porphyrinatocobalt (Ⅱ)was synthesized. By means of spectrophotometer technique, the equilibrium constants of theaxial coordination reaction were measured between this system and a series of imedazole lig-ands (2-Melm, N-Melm, EMIm, GMZ) which possess different steric hindrances. Theresults show that the size and the position of the substituting group on a ligand influence thestability of the axial coordinative product, and the equilibrium constants appear in the orderKGMz>KN-Mclm ＞K2-Mclm＞K2-Mclm＞KEMlm Alinear relationship was observed between △Hand T△Sinboth the symmetrical and unsymmetrical systems. The favorable enthalpy changecompensates the unfavorable entropy change and the compensatory enthalpy- entropy relationshipcontributes to the stability of complexes.
    Simulated Calculation of Aluminophosphate Molecular Sieves Structure and Stability
    LI Bao-Zong, XU Wen-Guo, QIU Shi-Lun, PANG Wen-Qin, XU Ru-Ren
    1997, 18(10):  1576-1579. 
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    By using computer modelling based on the lattice energy minimization technique,Berlinite and a series of aluminophosphate molecular sieve frameworks crystal lattice werecalculated including those of AlPO4-31, AlPO4-11, AlPO4-C, AlPO4-8, AlPO4-5,AlPO4-20, AlPO4-16, AlPO4-17, AlPO4-35, AlPO4-52, AlPO4-18 and VPI-5, and the geometriesand lattice energies of them were predicted. The relationship between the calculated latticeenergies and frameworks was discussed. The results reveal that the lattice energy decreasesand the relative stability of framework increases with the increase of frameWork density.
    A Study of Hydrothermal Synthesis and Properties of Rare Earth-modified PbTiO3 Fine Powders
    XIONG Rong, CHENG Hu-Min, MA Ji-Ming, CHEN Shou-Liu, ZHUANG Yong-Qiu, ZHANG Pei-Lin, ZHONG Wei-Lie
    1997, 18(10):  1580-1584. 
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    Lead titanate ceramics fine powders modified with several rare earth (La, Pr, Nd,Sin, Eu) were prepared by hydrothermal method. The transformation between tetragonal(ferroelectric) phase and cubic (paraelectric) phase for the La-doped PbTiO3 solid solutionwas investigated. Curie' temperature of the PTsolid solution with x(La)=0. 04 and y(Mn)=0. 01 was ca. 400 ℃. The dependences between rare earth-doping content and piezoelectricproperties of PTsolid solutions were determined. The d33, increased, while g33, kt and kt/kpecreased with increasing rare earth-doping content in PTsolid solutions.
    Synthesis and Crystal Structure of Some Rare Earth Nitrate Complexes with N, N-Disalicylideneethylenediamine,Dimethyl Sulfoxide
    KONG Fan-Rong, ZONG Rui-Fa, QIAO Chi-Bing, ZHANG Min, DING Chen-Yuan
    1997, 18(10):  1585-1589. 
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    The complexes of Tb (Ⅲ), Y (Ⅲ), Nd (Ⅲ) nitrate with N, N-disalicylideneethylenediamine, dimethyl sulfoxide as the ligands were synthesized. Their molecularcomposition are [RE(C6H5OHCHNC2H4NCHC6H5OH) (NO3)3 (CH3SOCH3)]. The molecularstructures of the complexes were determined by X-ray diffraction. The crystal of Tb (Ⅲ)complex is monoclinic with space group P21/n, a=0.9628 (3) nm, b=1.6439 (4) nm,c=1.6256(2) nm, β=102.78(2), V=2.509(2)nm3, Dx=1.830 g/cm3, Z=4, p=2. 996mm-1, F (000)=1638, R=0. 043, Rw=0. 046. The coordination number of Tb (Ⅲ) is 9 with the geometry of a monocapped square antiprism. All of coordination atoms are oxygenatoms. The two central ions were bridged by the two Schiff base, resulting in an infinitechain.
    Synthesis, Characterization and Crystal Structure of Position-isomer Ligands Contaning Dinuclear Copper(Ⅱ)Complex[CU(μ-Cl)(Cl)(C13H10N2S)2]2
    GUO Sheng-Li, LIU Sheng-Ming, YIN Yuan-Qi, YU Kai-Bei
    1997, 18(10):  1590-1593. 
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    The dinuclear copper(Ⅱ) complex containing position-isomer ligands [Cu (μ-Cl)(Cl) (C13 H10N2S)2]2 was synthesized and characterized by spectroscopy and X-ray crystalstructure determination. The crystal is monoclinic, space group P21/n, with unit celldimensions: a=1. 3322(2) nm, b=1. 5051 (2) nm, c=1. 3591(2) nm; a=γ=90°, β=110. 15(1)°, Z=2, R=0. 0688. Each copper atom is coordinated by two bridged chlorine atom,one terminal chlorine atom and two disubstituted pyrazole position-isomers. So, the copperatom has a distorted trigonal bipyramid configuration.
    Synthesis and Properties of [X(NbO2)W11O39]n-
    YANG Qi-Hua, DAI Hut-Cong, LIU Jing-Fu
    1997, 18(10):  1594-1596. 
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    Four new complexes MaHb[X (NbO2)W11O39]. nH2O (M=Me4N+, Bu4N+; X=Ga, Ge) were synthesized and characterized by elementary analysis, IR, UV-Vis,183W NMRand electrochemical method. 183W NMRspectra of the complexes consist of sixpeaks, as expected for monosubstituted Keggin-type.
    Simulation Calculation for Chemical Speciation of Pb2+-FA-SO42- System by Genetic Algorithms
    LIU Jia, DENG Bo
    1997, 18(10):  1597-1601. 
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    Fulvic acid (FA) has the marked effect on the chemical speciations of metal ionsexisted in water system and further affects their biological action as well as their remove andtransformation in ecosystem. In this paper, the chemical speciation of lead, an importantharmful and pollution element, in the aqueous solution containing FAand SO42- has been Cal-culated. The anode stripping current, i, can be measured using Ph2+ to titrate the aqueoussolution containing FAand SO42-by ASV. According to the chemical model of Pb2+-FA-SO42-constructed basing on material and chemical balance, the simulation calculation for thechemical speciations of lead have been made using a novel method of global optimization-ge-genetic algorithm (GA). The results of t test indicate that there is no significant differencebetween calculated and experimental values of anode stripping current.
    Studies on Solubilization Site of the Triplet Energy Acceptor Biacetyl in Normal Micelles by Using Quenched RTP Method
    XIE Jian-Wei, XU Jin-Gou, CHEN Guo-Zhen
    1997, 18(10):  1602-1606. 
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    The solubilization site of the triplet energy acceptor biacetyl in normal micelles isstudied by quenched RTP. Ethyl iodide, butyl bromide were used as hydrophobic quenchers.Potassium bromide, copper chloride were the hydrophilic quenchers. The results indicatethat biacetyl is located in the head group-water interface and likely to be lined up along thealkyl chains of the surfactant's aggregates but its carbonyl group is close to the head group ofsurfactant. So, if donor is located in the head group-water interface where biacetyl issolubilitized, enhanced energy transfer is observed.
    Bioconcentration, Elimination and Metabolism of 2,4-Dinitrotoluene in Carps (Cyprinus Carpio L.)
    LANG Pei-Zhen, CHEN Dao-Bi, WANG Ning, WANG Yi, DING Yun-Zheng
    1997, 18(10):  1607-1610. 
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    Bioconcentration curves of 2, 4-DNT in carps (whole fish, liver, intestine) wereinvestigated using semistatic systems. For whole fish, its curve could be described as agentle peak which began with a rise in concentration to steady state, then declined and reachedlower level followed by another steady state. For liver and intestine, their curves bothcontained two successive peaks. Bioconcentration factors (BCFs) of 2, 4-DNTin whole fish atthe first and second steady state were 9. 15 and 4. 15 respectively. By logarithmic ploting,two straight lines with different slopes 3. 6 and 0.1 d-1 were measured for elimination. Twometabolites were isolated by HPLCas 4-amino-2-nitrotoluene and 2,4-diaminotoluene, theirretention times were 23.1 and 8. 8 min respectively. Aone-compartment model was set up tosimulate the uptake, in which biotransformation adhered to delayed enzyme-catalyticlogarithmic kinetics. Modeling curve was in accord with measured values.
    Study on Immobilized Supramolecular inclusion Complex of Iron-Porphyrin as an Analogue for Peroxide Proteinase
    MAO Lu-Yuan, ZHU Min, HUANG Xue-Me, SHEN Han-Xi, LI Rong
    1997, 18(10):  1611-1615. 
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    The Supramolecular inclusion complex of iron-5, 10, 15, 20-tetrakis[4-sulfophenyl]-21H, 23H-porphin (FeTPPS4) with p-cyclodextrin cross-linking polymer(β-CDP) was obtained and used as an analogue for peroxide proteinase. The effects of variedfactors on formation constant of the inclusion complex were investigated. The mechanism ofimmobilized supramolecular complex catalyzing p-chlorophnic acid by hydrogen peroxide wasstudied in detail. The immobilized inclusion complex as mimests of horseradish peroxidasewas very stable and found to exhibit the high proteinase-like activity, which have beendemonstrated by enzymatic methods of analysis. The method was applied to determinehydrogen peroxide with 4-aminoantipyrine and p-chlorophenic acid. The calibration curve forabsorbance-concentration(H2O2) was linear from O to 3. 0 μg/mLand the linear correlationcoefficient was 0. 9994.
    The Studies on the Use of Calix[4]arene in Capillary Electrophoresis
    HU Xu-Bo, LU Xue-Ran, ZHAO Tao, CHENG Jie-Ke
    1997, 18(10):  1616-1617. 
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    The behavior of water-soluble p-sulfonic calix[4]arene in capillary electrophoresiswas first reported. Amixture of nitrophenol isomers was completely separated using only 3 mmol/Lcalixarene. The efficiency of 3. 0 × 105 plates/m was achieved and the detectionlimits were 33. 6, 21. 8 and 16. 2 pg for o-, m- and p- nitrophenol respectively under thecon-ditions fused-silica capillary(44 cm ×50 μm i. d., effective length 37 cm), phosphate buffer(50 mmol/L, PH5.0), 25℃, 14 kV, 275 nm and 1 s vacuum load.
    Studies on Zeolite Modified Electrode (Ⅱ)──Stripping Voltammograms of Ph2+ on Zeolite-Polyvinyl Electrode
    ZOU Ming-Zhu, LU Jie, RU Qin-Hua
    1997, 18(10):  1618-1620. 
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    Anew zeolite modified electrode was prepared by using zeolite/polyvinyl as amodifier on GCE. The anodic stripping voltammograms of Pb2+ on ZPEis caused by zeoliteselective adsorption to Pb. The linear range of Pb2+ in 0.5 mol/L KCl(pH=2.0) solution is1. 0 × 10-6～1. 0 × 10-3 mol/Lwith 0. 999 correlation coefficient (n=6). The relativestandard deviation of the response to 4. 0 × 10-6 mol/L Pb2+ on ZPEwhich has been repeatedlyproduced for ten times is 2. 5 %. The detection limit is 3. 0× 10-7 mol/L Pb2+. To the 1. 0×10-6 mol/L Ph2+, 1000 times Al3+, Na+, K+, Cl-, SO, NO3-, Hg2+, 100 times Ni2+,Co2+, Cu2+, Zn2+, Cd2+, Mn2+ and 10 times Ca2+, Fe3+, Mo6+, Cr3+ do not disturb theanalysis. The ZPEshows a high selectivity, sensitivity and a desired reproducibility. Itssensitivity dropped to 90% of the original value after it had been continuously used for thousandtimes.
    Amberlite XAD-2 Resin Microcolumn Coupled On-line to a Flow Injection Approach for the Preconcentration, Clean-up and Determination of Trace Phenols in Waters
    SONG Wen-Lu, WANG Lian-Sheng, ZHI Zheng-Liang
    1997, 18(10):  1621-1623. 
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    Anovel and expeditious approach for direct determination of phenols in water andwaste water based on solid-phase extraction coupled to a flow injection analysis (FIA)manifold is described. The method employs on-line preconcentration of phenols using a 3 cm×3mm column packed with Amberlite XAD-2 resin. The phenols are subsequently eluted fromthe resin into a flowing system with an alkaline solution and quantifiedspectrophotometrically as the products of reaction with 4-aminoantipyrine (4-AAP) system. Thesensitivity offered by the procedure was higher by a factor of pH=13 than that provided by aconventional FIAmethod.
    Studies on the Mechanism of Dimerization of Organomercuric Compounds by Rhodium(Ⅰ)
    WANG Yu-Lan, WU Yang-Jie, CAI Meng-Shen, YIN Ying-Zhe
    1997, 18(10):  1624-1627. 
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    The kinetics of dimerlzation of β-naphthylmercuric chloride in the presence of[CIRh (CO)2]2 has been studied in hexamethylphosphoramide. The dimerization has beenfound to be second order and the kinetic parameters of the dimerization have been reported.Both α-naphthylmercuric chloride and α-bromomercuriphenylacetate have not beendimerizated under the same reaction conditions, which has been explained on the basis of the proposedmechanism. The organic rhodium (I) intermediate formed in the α-bromonercuriphenylacetate case was isolated and identified.
    Protection of Myocardial Mitochondria Against the Active Oxygen Injury by Horseradish Peroxidase
    XING Hui, FENG Yan, GAO Gui, CHEN Si-Geng, YANG Tong-Shu
    1997, 18(10):  1628-1632. 
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    The protection of myocardial mitochondria against the free radical injury byhorseradish peroxidase was studied. The free radical injury model of mitochondria in vitrowas set up. Horseradish peroxidase could inhibit the generation of free radicals and lipidperoxides, keep cytochrome oxidase of mitochondria membrane with a high activity, and makethe mitochondria remain relative intact in structure. The results suggest that horseradishperoxidase as peroxide scarvenger could decrease the free radical injury of mitochondria.
    Using Molecular Graphics, Molecular Mechanics, Quantum Chemistry and Electrostatic Potential Methods to Study Structure-Property Relationship on Pesticides(XI)──The Structural Characteristics of Antiviral Compound──Piperonal-(4-Quinazolinyl)
    LI Hui-Ying, WANG Xia, HUANG Run-Qiu, MA Jun-An, QIU De-Wen, YUAN Man-Xue, LAI Cheng-Ming
    1997, 18(10):  1633-1636. 
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    Synthesis and crystal structure of title molecule were reported here. The crystalconsists of two compounds with similar structure. The crystal is monoclinic, belonging tospace group P21, with unit cell parameter α=0. 8431 (3) um, b=0. 7297(1) um, c=2. 1880(7) um, β=100. 90(3)°, V=1. 322(1)nm3, Z=2. And we have reported the studyon some other possible conformations and the rotation barrier by molecular mechanicsMMX. We also used the UNDOto calculate the distribution of charges and the CNDO/2electrostatic potential curve was presented.
    Molecular Recognition Between Rhodamine B-(alkylamino)cyclodextrin Complexes Probe Type Host Molecule and the Guest Molecule
    FENG Xi-Zeng, XING Wan-Li, CAO Ying, HE Xi-Wen
    1997, 18(10):  1637-1641. 
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    in this paper, we have studied the interaction between a nenthesized probe type host molecule, RhB-β-CDcn, and DNAas well as the effect of temperature upon thefunction of this probe using spectrum method. The mode of the interaction between probemolecule and DNA, the ability of their intercalation and the effect of temperature upon hostmolecule containing guest molecule were discussed. In addition, the mechanism ofrecognition between the host molecule and the guest molecules was also studied.
    Synthesis of Organosilylferrocene and 2-(Tributyltin)-ferrocene Derivatives
    DU Hong-Guang, SHI Xin-Xu, YE Ji-Dong, SHI Shu-Jian
    1997, 18(10):  1642-1647. 
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    N, N-Dimethylaminomethylferrocene (Ⅰ) was lithiated to the monolithio com-pound, which was then reacted with an equimolar trimethylchlorosilicane to form 2-(trimethylsilyl) dimethylaminomethylferrocene (Ⅱ). When the monolithiated Ewas con-densed with trimethylchl0rosilicane, 2, 5-di(trimethylsilyl) dimethylaminomethylferrocene(Ⅲ) was obtained. The monolithiated Ⅰ was allowed to react with half-molar dimethyldich-lorosilicane to yield bis [2-(N, N-dimethylaminomethyl) ferrocenyl] dimethylsilicane (Ⅳ)-2, l'-Dilithiated Ⅰ was obtained by lithiating Ⅰ in the presence of N, N, N', N' -tetra-methyl ethylene diamine (TMEDA) and then condensed with double molartrimethylchlorosilicane to give 2, 1' -bis (trimethylsilyl)dimethylaminomet (Ⅴ).The structure of pr0ducts Ⅱ- Ⅴ were confirmed by elemental analysis, 1H NMRand MS.The methi0dide of 2-(tributyltin)dimethylaminometh was allowed to react with anumber of nucleophiles: sodium methoxide, sodium ethoxide, sodium phenolate, substitutedphenolates, piperidine, aniline, N-methylaniline and o-C6H4(CO)2NK. Ten new 2-(tributyltin)ferrocene derivatives were obtained and the structures of the ten products were de-termined by elemental analysis, IRand 1H NMR.
    The Cleavage of Trimethylsilyl Ether
    WANG En-Si, SHEN Jia-Cong, Henry N. C. WONG
    1997, 18(10):  1648-1650. 
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    Trimethylsilyl ether of tertiary alcohol can be cleaved by using tetra-n-butylan-monium fluoride (TBAF), acidic hydrolysis, basic alcoholysis and and BF3-Et2O. The resultsshow that BF3-Et2O is a highly selective method, which has not been reported so far.
    Synthesis and Bioactivity of 5-Amino 1,2,3-thiadiazole Derivatives
    ZHAO Wei-Guang, LI Zheng-Ming, CHEN Han-Song
    1997, 18(10):  1651-1653. 
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    Ten new 5-amino-1, 2, 3-thiadiazole derivatives containing benzenesulfonylureas,Schiff bases and amides were synthesized. Their structures were confirmed by 1H NMR, IR,MSand elementary analysis. The preliminary biological tests show that compound 8 hasbiological activity.
    Crystal Structure and Mechanism of (Z)-1-[2-(Phenyl-bromide-chloride) vinyl]-1-cyclohexanol
    ZHU Dong-Sheng, DAI Hui-Cong, FU Yu-Jie, SHAN Xi-Lin, FU Fang-Xin, XING Yan, LIN Yong-Hua
    1997, 18(10):  1654-1656. 
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    The crystal structure and mechanism of the title molecule are discribed. Thiscrystal is orthorhombic, belonging to space group PC21/Bwith α=1. 0021 (2) nm, b=1. 4830(3) nm, c=2. 1736(4) nm, V=3. 23039(2) nm3, Z=2, Dc=1.80 g/cm3, R=0. 0693. The structure was solved by direct method. The tin atom of the title compoundexists in two distorted-trigonal-bipyramidal geometry, defined by two carbon, one bromide,one chloride and one oxygen atoms leading to a five-membered chelate ring. In the structure,the five-membered ring containing the intermolecular O→Sn has a half chair conformation.
    Spectroelectrochemical Studies of the Conducting Polymer of o-Phenylenediamine
    WU Ling-Ling, LUO Jin, LIN Zhong-Hua
    1997, 18(10):  1657-1663. 
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    The redox mechanism of the conducting polymer film of poly-o-phenylenediamine(P-o-PD) in acid solution has been studied by cyclic voltammetry(CV), electrochemicalinsitu resonance Raman spectroscopy and UV-Vis subtractive reflectance spectroscopy. Theresults of the CVshow that the redox process of P-o-PDis controlled by the surfaceprocesses and three steady redox states are formed in the redox process. The in-situ resonanceRaman spectra not only verify the existence of the three steady states of P-o-PD, but alsoindicate that the structure of P-o-PDis dominated by a ladder polymer with phenazine rings. Thethree kinds of P-o-PDdisplay different stabilities and UV-Vis aborption spectra.Furthermore, the in-situ time--resolved UV-Vis reflectance spectroscopy is used to study the dynamicredox process of P-o-PD, and a possible reaction mechanism is proposed at last.
    The SMO-CDCI Method of Linear Molecules Based on Group Symmetry Orbital(SMO)and Character Determinants(CD)
    ZHOU Tai-Jin, MO Yi-Rong
    1997, 18(10):  1664-1668. 
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    The new finite groups called C* and D*, which correspond to C∞υ. and D∞h pointgroups, respectively, are introduced. The significant advantage of C* and D*is theirsimplicity and completeness to classify molecular orbitals for all of linear molecules. Groupsymmetry orbitals (SMO) and character Slater determinants(CD) of linear molecules based upon C* and D*groups are definited and discussed. Apreliminary singly and doubly excitedcharacter configuration (CD-CISD) program is developed, and the pilot calculations about thesimple linear molecules are performed and compared with that by the programGAUSSIAN94. The calculation results proved that the CD-CISDis a high effective calculation methodfor linear molecules.
    Kinetic Studies on the Formation Reaction of Cadmium(Ⅱ)with Porphyrin and the Salt Effect
    RUAN Wen-Juan, ZHU Zhi-Aug, CHEN Hong-Wei, LIN Hua-Kuan, SHAO Ying, YANG Xiu-Lin, CHEN Rong-Ti
    1997, 18(10):  1669-1674. 
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    The kinetics of formation reaction of Cd(Ⅱ) with meso-tetra-meta-toluene-porphyrin [H2T(m-CH3)PP] in acetone has been studied by means of stopped-flow method. Theproper reaction mechanism was proposed. The effects of temperature on the reaction ratewere investigated. It was found that kobs was reduced with the increase of the ionic strength,that is, the negative kinetic salt effect was observed. According to Debye-Huckel theory andthe experimental results a good linear relationship between rate constant and ionic strengthwas obtained.
    Studies on the Thermal Change and Intermediate Involved in the Synthesis of γ-Mo2N
    YANG Shu-Wu: XU Jiang, YAN Wei-Hong, YING Pin-Liang, GAO Xiu-Ying, QI Xing-Yi, XIN Qin
    1997, 18(10):  1675-1679. 
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    The thermal change in the synthesis of γ-Mo2Nby temperature-programmedreaction of MoO3 with ammonia has been studied by differential thermal analysis (DTA)technique, IR, BETand XRDmeasurements. The DTA results show that both exothermic andendothermic peaks appear in the process. With the increase of temperature-elevation rate,the areas of the exothermic peaks increase, and the areas of the endothermic peaks decrease.XRDand IRresults show that the exothermic peaks are attributed to the reduction of MoO3to MoO2 and the endothermic peaks can be assigned to the nitridation of MoO2 to γ-Mo2N.The nitriding product is γ-Mo2Nat the lower rates of increasing temperature (≤3 K/min),whereas the products are γ-Mo2Nand MoO2 at the higher heating rates(≥5 K/min). Andthe higher the rate, the more MoO2 was formed in the final product. It is suggested that NH3first interacts with MoO3 and reduces the MoO3 into MoO2, and then the MoO2 is nitridedin to γ-Mo2N.
    Raman Spectroscopic Studies of Fe(CN)63-/4- Redox Process at Gold Electrode Surfaces
    GU Ren-Ao, YAO Jian-Lin, YUAN Ya-Xian, TIAN Zhong-Qun, REN Bin
    1997, 18(10):  1680-1682. 
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    By using surface-enhanced Raman spectroscopy, we studied the redox process of Fe(CN)63-/4- couple on a roughened gold electrode surface. The results show that the Fe(CN)63- is much more strongly adsorbed on the gold electrode surface, and it is via CNligands interacting with gold electrode surfaces.
    Highly Active Hydrogenation Catalysts from Titanocenes and Sodium Hydride of Nanometric Size
    FAN Yin-Heng, LIAO Shi-Jian, XU Jun, QIAN Yan-Long, HUANG Ji-Ling
    1997, 18(10):  1683-1687. 
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    The hydrogenation of 1-hexene was catalyzed by titanocene with varioussubstituted groups in combination with nanometric sodium hydride. When the steric hindrance ofthe substituted group on the cyclopentadienyl ring is relatively small, the titanium complexgives high initial catalytic activity but poor stability, whereas when the steric hindrance islarge (for instance, five-membered ring or six-membered ring), the titanium complex giveslower initial catalytic acitivty but better stabilty. At normal temperature and pressure, amaximum turnover frequency(TOFmax) of H2/(mol Ti·s) and a turnover(TO) of22200 mol H2/(mol Ti) were obtained by using bis [(1'-ethyl)cyclohexyl-cyclopentadiTiCl2/NaH*as catalyst. Only the terminal olefin could be hydrogenated by using this kind ofcatalytic system. Isomerization of olefins did not occur in the course of hydrogenation. It isthe key factor that the nanometric NaH*was used as the cocatalyst in the reaction. Thecombination of titanocenes with commercial sodium hydride which was synthesized at hightemperatures did not display any catalytic activity for the hydrogenation of 1-hexene.
    Theoretical Study on SN2 Reactions Between Methyl Nitrate and Various Nucleophiles
    GONG Xue-Dong, XIAO He-Ming, GAO Pin
    1997, 18(10):  1688-1691. 
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    Ab initio and semi-empirical NO AM1 methods have been employed to study theelectronic structures of a series of nucleophiles and methyl nitrate, and the gas-phase SN2reactions between them. The regularity of changes of structure, energy and charge during thereaction are investigated. According to the calculated activation energies of the reactions, themagnitude of the nucleophilicity of eight nucleophilies is given asOH-＞F-＞I-＞NO3-＞CN-＞Br-＞Cl-＞N3-.
    Theoretical Study on the Unimolecular Fragmentation of Ionized Tetrahydroimidazole-substituted Methylene β-Diketones
    WEI Jun-Hua, SHE Yi-Min, XU Wen-Guo, LIU Shu-Ying
    1997, 18(10):  1692-1694. 
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    Semiempirical molecular orbital calculations on the unimolecular massspectrometric fragmentation of tetrahydroimidazole-substituted methylene β-diketones are carried outby Austin Model 1 method, and the calculated results give a strong support to ourexperimental results reported previously. The optimum of the investigated molecular configurationindicates that the two hydrogen atoms attached to nitrogen atom have different activities dueto their chemical environment; the relative energies of the ions in fragmentation pathway ofionized tetrahydroimidazole-substituted methylene β-diketones provide indirectly an evidencefor both the existence of ion/neutral complex and the stabilities of these ions.
    Purification of Yeast-Lipase by the Phase Transfer Method of Reverse Micelles
    CHU Ying, JI Jian-Ye, MA Zhan-Fang, YU Yan-Chun, WU Zi-Sheng
    1997, 18(10):  1695-1697. 
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    The preliminary result of the yeast-lipase purified and separated by the reversemicelles system of AOT/iso-octane is reported in the paper. The phase transfer mechanismof the static interaction in the process of the phase transfer of reverse micelles as well as thehydroplic interaction was studied based on the extractive efficiency of lipase and the recoveryefficiency of protein affected by pHvalue of water phase and salt concentration. Theinteraction between enzyme molecules and reverse micelles was reduced and the recovery efficiencyof protein and enzyme activity was increased significantly when deoxycholic acid was addedinto the reverse micelles of AOT/iso-octane as the biological surfactant. The relative activityof lipase recovered was increased by 4%～9% compared with origin enzyme aqueous in therange of pHinvestigated.
    Studies of Methane Reforming with Carbon Dioxide over LaNiAl11O19
    JI Min, BI Ying-Li, ZHEN Kai-Ji, WU Yue
    1997, 18(10):  1698-1699. 
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    Anew type of the catalyst, LaNiAl11O19 for the methane reforming with carbondioxide was synthesized and evaluated. LaNiAl11O19 has a hexaaluminate structure and cankeep large surface and heat resistance against sintering at high reaction temperature. Ascompared with La2O3-Ni/SrAl12O19, in the CH4+CO2 reaction, LaNiAl11O19 catalyst displaysa higher catalytic activity, lower coking amount and excellent sintering resistance of Niparticle, due to its stable structure.
    Quenching Effects of NO2, H2O and N2 on the Iodine Fluorescence
    WANG Miao-Miao, TANG Yong-Xin, ZHENG Qi-Ke
    1997, 18(10):  1700-1702. 
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    The quenching effects of N2, NO2 and H2Oon the laser-induced fluorescence of I2in a wide pressure range are reported. The quenching rates of N2, NO2 and H2Oare 6. 57 ×103Pa-1, 2. 58 × 10-2 Pa-1 and 1. 50 × 10-2 Pa-1, respectively. The results imply thatdipole-induced dipole interaction plays an important role in the quenching process, and thestatic quenching of NO2 on I2 fluorescence could be attributed to the metastable complexformation of I2 and NO2
    Deprotonation of Meso-tetra(p-hydroxylphenyl) Porphyrin with a Hexadecyl Chain in CTAB Micellar Microenvironment
    ZHANG Yun-Hong, GUO Lin, LI Qian-Shu, WANG Yong-Qiang
    1997, 18(10):  1703-1705. 
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    The deprotonation of an amphiphilic porphyrin, meso-tetra (p-hydroxylphenyl)porphyrin with a hexadecyl chain(THPPH2), has been observed by means of UV-Visspectroscopy in CTABmicellar solutions. With increasing of PHvalues, the Soret band shiftsfrom 424 nm to 441nm, and the four-Qbands (520 nm, 560 nm, 595nm, 655 nm) aredisappeared while two new Q-bands are appeared at 585 nm and 675 nm, which is similar tometal-porphyrin, means that the deprotonation of porphyrin takes place. Comparing withthe spectra in an other solutions, the spectral characteration of THPPH2 in neutral and inbasic CTABsolutions is similar to that in CHCl3 and basic aqueous solutions respectively,suggesting that the solubilizing location of THPPH2 takes a change from inner to the outer of theCTABmicellars with the PHvalue of solutions increasing between 6.20 and 11.19.
    Studies on the Syntheses and Drug Release Properties of Polyanhydrides Containing Phosphonoformic(or Acetic)Acid Ethyl Ester in the Main Chain
    FU Jie, ZHUO Ren-Xi, FAN Chang-Lie
    1997, 18(10):  1706-1710. 
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    Polyanhydrides were synthesized by melt polymerization of his (p--carboxyphenyloxy ethoxy), phosphonoformic (or acetic) acid ethyl ester 1(or 2). Copolyanhydrides weresimilarly prepared from 1 (or 2) and his(p--carboxyphenoxy)propane (CPP), or sebacic acid(SA). The chemical stru ctures of these new polyanhydrides and copolyanhydrides wereconfirmed by 1H NMR, FTIRand elemental analysis. The average molecular weight of thesepolymers was investigated. In vitro degradation of polyanhydrides and copolyandhydrides inphosphate buffer solution at 37 oC was monitored by HPLC. Experimental data revealed thatfission of phosphate bond took place after that of the anhydride bond. Enzymatic degradationshowed that Ribonuclease could catalyze and accelerate the degr adation of thesepolyanhydrides. Drug release profile of antitumor agents MTXand 5--Fu were also studied.
    ESR Study on Stable Cation Radical of a Conjugated Polymer
    ZHANG Rui-Feng, ZHENG Hai-Peng, SHEN Jia-Cong
    1997, 18(10):  1711-1714. 
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    Poly(N,N-dimethylaniline) (PDMA) is a novel soluble polyphenylene derivative,which is very easy to form delocalized and stable canon radicals in CHCl3. In this paper, wemainly studied the interaction between the cation radicals of PDMAand amines. It' Sfoundthat the interaction could lead to PDMA' S ESRspectra split, and the structures of aminesrelate to the change of PDMA' Ssignal strength and split, which showed that PDMA' scanon radical turned partly into localized state with nucleophile. We also discussed itselectrophilic activity and contrasted with the cation radical of polyphenylene.
    Preparation and Characterization of a Series of Intermolecular Hydrogen Bonded Liquid Crystalline Complexes
    TIAN Yan-Qing, ZHANG Yan-Jie, ZHAO Ying-Ying, TANG Xin-Yi
    1997, 18(10):  1715-1718. 
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    Aseries of intermolecular hydrogen bonded liquid crystals between 2-cyano-3-[4(2-chloro-3-methyl-l-butanoy- acrylic acid (A) and N- (4-pyridylmethylidene)anilines(nSSZ) were prepared and investigated by DSC, polarizing microscopy and X-raydiffraction. The results showed that these complexes exhibited smectic Aphases.
    Studies on Reaction Kinetics of o-Cresol Novolac Resin Using Phenol Novolac Acetate as Curing Agent by FTIR
    LUO Xiao-Wen, LI Shan-Jun, DING Ya-Di, PING Zheng-Hua
    1997, 18(10):  1719-1723. 
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    FTIRin situ was used to study the isothermal reaction kinetics of o-cresol novolacresin using phenol novolac acetate as the curing agent in the presence of 2-methylimidazole.Some kinetic parameters of the curing reaction were obtained. The results show that thiscuring process followed a first-order kinetics. The possible mechanism of cured reaction wasdiscussed according to variation in absorption bands of C=O during the reaction.
    The Adsorption of Urea by the Oxidation of a TDI Crosslinked β-Cyclodextrin and Its Composite Adsorbent with Dialytic Membrane
    SHI Lin-Qi, LI Zhan-Yong, HE Bing-Lin
    1997, 18(10):  1724-1728. 
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    Anovel adsorbent with an aldo structure was obtained by the oxidation of acrosslinked p-cyclodextrin polymer. The highest urea adsorption capacity reached 56 mg/g at 37℃ and PH 7.4. The composite adsorbent was prepared by the oxidation of a TDIcrosslinked β-cyclodextrin resin and dialytic membrane. It was found that the compositeadsorbent has a higher urea adsorption selecitivity and capacity compared to that of theoxidation of a TDIcrosslinked p-cyclodextrin resin when urea is in aqueous human serumalbumin.
    The Preparation of a Novel Adsorbent for Triglyceride and Its Adsorption Properties for Triglyceride in Serum
    YU Yi-Hua, SUN Jun-Tan, HE Bing-Lin, GU Han-Qing
    1997, 18(10):  1729-1733. 
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    Sulfonated hydroxyethylated crosslinked chitosan beads, which can selectively adsorb triglyceride, were prepared by the reaction of hydroxyethylated crosslinked chitosan and ClSO3H, using DMFas solvent. Adsorption experiments were performed by adding thebeads to the serum. The results showed that this type of adsorbent could cut down the concentration of triglyceride in plasma by 76. 9% at most, while the concentration of total protein(TP) decreased only by 2. 6% at least, so this novel adsorbent can be expected to be used for curing hypertriglyceridemia in the future.
    Tacticity Distributions of Polypropylene Prepared with Supported Ziegler-Natta Catalysts
    XU Jun-Ting, FENG Lin-Xian, YANG Shi-Lin
    1997, 18(10):  1734-1735. 
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    Polypropylene samples prepared with supported Ziegler-Natta catalysts were fractionated with temperature rising elution fractionation(TREF) technique and the tacticity distributions were obtained. It is found that the polypropylene sample has a broad tacticity distribution when there exists no electron donor in the catalyst. the mutiple maximal wi(%)/At values indicates the presence of plural active sites in the catalysts. Experimental results show that both external and internal electron donors can narrow the tacticity distribution of PP.When external and internal electron donors are present in the catalysts, the obtained PPhas the narrowest tacticity distribution.
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