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Table of Content

    24 October 1998, Volume 19 Issue 10
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    Articles
    Synthesis and Structure of a New 4,4'-Bipy-bridged One Dimensional Hetero-metallic Compound with Macrocycle Ligand {[Cu(trans[14]diene)SCN]2Mn(SCN)4(4,4'-bipy)·4H2O}n
    SHEN Hao-Yu, SUN Bai-Wang, LIAO Dai-Zheng, JIANG Zong-Hui, YAN Shi-Ping, WANG Geng-Lin, YU Kai-Bei
    1998, 19(10):  1533-1536. 
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    The studies of one dimensional compounds have attracted chemists for many interests, because they are not only important for molecular designing and magnetic materials, but also the basis of studying high dimensional compounds.
    Studies on the Property of Oxygen-deficient Ferrite MFe2O4-δ
    ZHANG Chun-Lei, LI Shuang, PENG Yan-Bing, WU Tong-Hao, ZHANG Mi-Lin, PENG Shao-Yi
    1998, 19(10):  1537-1541. 
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    In the present paper, the lattice constant, magnetism, stability and reducing property of oxygen-deficient ferrite MFe2O4-δ (δ >0, M=Fe, Co, Mn, Ni) have been studied by XRDand Mssbauer methods. It is found that the lattice constant of MFe2O4-δ (δ>0) is larger than that of MFe2O 4+δ, while its internal magnetic field is smaller than that of MFe2O 4+δ. With increasing the deficiency degree δ, the lattice constant increased, and the internal magnetic field decreased. MFe2O4-δ is unstable in air at room temperature, but it can exist steadily in inert gas at low temperature(<673 K), MFe2O4-δ possesses very strong reducing power and can reduce CO2 to Cat 573 K.
    Synthesis,Structure and Properties of BaZrxTi1-xO3·yLa2O3 Solid Solutions
    DING Shi-Wen, MA Guang-Cheng, GUO Xiang-Hui, WANG Zhi-Qiang, LI Jin-Long, CHEN Jing, LI Ying
    1998, 19(10):  1542-1545. 
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    Aseries of BaZrxTi1-xO3·yLa2O3(0≤ x ≤0.3, 0≤ y ≤0.04) solid solutions were synthesized by means of soft chemical method at 95 ℃. XRDand d-spacing-component figures of the series of the solid solutions proved that the compounds are mutual miscible in the solid solutions. Further, through a TEM, the product is found to have a shape of uniform, substantially spherical particles with an average particle diameter of 60 nm. The result of preparing ceramics showed that adulterating with zirconium and lanthanum in pure BaTiO3 phase obviously improved the dielectric constant at normal temperature.
    Preparation,Structure and Properties of Dinuclear Cu(Ⅱ) Schiff Base Complexes with Different Type of Bridging Groups
    YIN Ye-Gao, CHEUNG Chung-Kai, Huang-Yong-De
    1998, 19(10):  1546-1550. 
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    Three dinuclear Cu(Ⅱ) complexes with oxalate (Cu2(L1)2(ox), 1), acetate (Cu2(AcO)(L2)2 BF4, 2) and phenolate group(Cu2(L3)2 (ClO4)2, 3)as bridging group, individually, were synthesised, and the crystal structures of composite complex Cu2(L1)2(ox) · Fe(OH)2(H2O)4 ClO4·H2O (1') and complexes 2 and 3 were determined. X-ray crystal structure analyses comfirm that the crystals of 1', 2 and 3 exist in Fddd, P21 / c and P21 / c space group, respectively. The crystal cell parameters of 1' are: a =2.4390(4) nm, b = 3.0538(6) nm, c =1.8494(6) nm, α=β=γ =90.00° and these of 2 are:a =0.847(1) nm, b =2.6542(8) nm, c =1.4100(6) nm, β =91.34(6)°; 3: a =0.7646(3) nm, b =1.6983(3) nm, c =2.4417(3) nm, β =97.11°. Electrochemical investigations of 1 and 3 show that bicopper(Ⅱ) centre experiences a mix-valence species during the course of reduction scan.
    Studies on the Synthesis,Characterization and Catalysis of a New Type of Layered Pillared Materials
    ZHU Zhi-Ping, ZHANG Xian-Hua, LIU Jing-Fu
    1998, 19(10):  1551-1552. 
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    Anew type of layered materials pillared by heteropolyanions SiW9M3(M=Mn 2+, Cr 3+, Ti 3+, Fe 3+) were synthesized by means of ion exchange reaction and characterized with elementary analysis, XRD, IRand DTA. The experiments showed that this pillared layered materials had higher catalytic activity for the epoxidation of maleic acid with H2O2.
    Studies on the Influence of Eu3+ and Al3+ Ions to the Temperature of the Gel to Liquid-crystalline of DPPC Bilayer
    XU Hong-Wen, FU Su-Ran, ZHANG Shu-Kong, XU Zhen-Hua
    1998, 19(10):  1553-1555. 
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    The experimental data on FTIRand NMRspectra show that the interaction of Eu 3+ and Al 3+ ions with DPPCbilayer can alter the temperature of the gel to liquid-crystalline phase transition of DPPCbilayer (increase of about 3 ℃). It can be found that Eu 3+ ion binding to DPPCbilayer makes the radius of DPPCbilayer small, while Al 3+ ion binding to DPPCbilayer makes it large. The complex reaction of Eu 3+ and Al 3+ ion with DPPCbilayer leads to a structual change of the polar head group in DPPCbilayer.
    The Gradient Distribution of Mobile Phase in HPLC
    LI Rui-Jiang, ZHANG Wei-Bing, NI Jian-Yi, ZOU Han-Fa, ZHANG Yu-Kui
    1998, 19(10):  1556-1559. 
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    In the gradient elution of HPLC, the delay and dispersion of mobile phase during the transmission of mobile phase in column, and the out column effect result in that, there is a gradient distribution in the variation of mobile phase content with time at any location in column, and it obeys a distribution law. In this paper, the law is discussed theoretically and experimentally, and the effect on the law of instrumental condition and different solvents is also discussed.
    Microwave-assisted Extraction of PAHs from Soils
    XIONG Guo-Hua, LIANG Jin-Ming, ZOU Shi-Chun, HE Xiao-Qing, ZHANG Zhan-Xia
    1998, 19(10):  1560-1565. 
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    The procedure of microwave-assisted extraction(MAE) of PAHs from synthetic soil samples has been studied with a MK-1 pressure automatically controlled sample-dissolving system. The digestion vessels coupled with this system were improved to suit to MAE. The optimum parameters for MAEof PAHs from soil have been studied in detail. Experimental results show that the MAEefficiency was influened by the solvent type, the microwave radiation time and the soil moisture and matrix. It was found that the MAEefficiency obtained by using acetone-hexane(volume ratio 1:1) was some equal to by using dichloromethane. The optimum MAEconditions for 2 g dry sample are as follows: adding water to 15% moisture, then adding 30 mLacetone-hexane(volume ratio 1:1), microwave power being at 600 W, pressure at the first stage(0.1～0.5 MPa) and microwave heating for 6 min. The extracts were detected by HPLC. The recoveries of naphthalene, acenaphthylene, fluorene, phenanthrene, anthracene, chrysene and benzopyrene were in the range of 82.2%—94.1%. Compared with the classical Soxhlet extraction, MAEis a more efficient, time-saving and solvent-saving method.
    Studies on Adsorption Properties of Chromium(Ⅵ) on the Nanometer-size TiO2 Powders Surfaces Using On-line Flow-injection Analysis
    MA Wan-Hong, CAI Ru-Xiu, LIN Zhi-Xin
    1998, 19(10):  1566-1569. 
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    Various of nanometer-size TiO2 samples are prepared from TiCl4 under different hydrolysis and calcining treatment conditions, such as pH, surfactants, stabilizers and temperature. It has been found that powders heat-treated at the temperature below 450 ℃ are of anatase crystal structure with average grain size of less than 20 nm. Adsorption behavior of Cr(Ⅵ) ion on as-prepared powders, adsorption kinetics, pHcurves, adsorption isotherms and adsorption capacity are studied by flow-injection micro column system for preconcentration using spectrophotometric detection method. The results demonstrated that nanometer-size TiO2 possesses a significant capacity and exchange rate for adsorption of Cr(Ⅵ) ion(approximately 3080 μg/g and 8.6×103 s-1).
    Studies on the Resonant Luminescence Spectra of Ethyl Violet with Deoxyribonucleic Acid and Its Analytical Application
    LI Tian-Jian, SHEN Han-Xi
    1998, 19(10):  1570-1573. 
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    The binding reaction and resonant luminescence spectra of ethyl violet with ctDNAhave been studied. In the pHrange of 5.0—10.0 ethyl violet exhibited a maximum of absorption at 595 nm. Anew absorption peak at 507 nm appeared when ctDNAwas added. It showed that a binding product of ethyl violet with DNAformed. The product emitted a sharp resonant luminescence peak at 510 nm. The intensity of resonant luminescence was found to be dependent on the concentration of DNA. The linear range of the calibration graph was 0—500 ng/mL. The limit of detection(3 σ) was 1.54 ng/mL. Anew method of resonant luminescence for the determination of trace DNAwas established with high sensitivity and selectivity.
    Adsorptive Voltammetry Behavior of Trace Dobutamine on Carbon Paste Electrode and Its Determination
    YANG Gong-Jun, JIN Li-Tong, LENG Zong-Zhou, CHEN Wen-Jian
    1998, 19(10):  1574-1577. 
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    Dobutamine is determined by adsorptive voltammetry using a carbon paste electrode in a base solution of 01 mol/L H2SO4. The peak potential of anode is 0.46 V(vs. SCE). There is a good linear relationship between the peak current and the concentration of dobutamine in the range of 30×10-9 ～10×10-6 mol/L. The detection limit of the method is 15×10-9 mol/L. The recovery is 94.00%～102.59%, and the relative standard deviation is 3.1%(n =9). The possible reaction mechanism is discussed.
    Laser MS Study of Self-assembled Mono-and Dilayer Film of C60 with Ethylene Diamine as Intermolecular String
    LI Jun, DENG Hui-Min, LAI Zhi-Hui, LI Tian-Bao, ZHAO Shan-Kai
    1998, 19(10):  1578-1580. 
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    Self-assembled film of C60 with ethylene diamine as intermolecular string were analyzed by the method of laser time-of-flight mass spectrometry. Similar mass spectra were found for self assembled monolayer film of C60 on glass or silicon surface. For the glass film, the highest ion was C112+, while for silicon film was C102+. When n >32, the fragmentation of Cn showed the lost of two carbon atoms each time. And the adduct(C60 + ethylene diamine) wasn't found in the spectra. It was assumed that at such a condition only C60 and its dimer are desorbed. The reason was that the bond between ethylene diamine and the surface of glass or silicon were stronger than that between ethylene diamine and C60. The spectra of self assembled dilayer film of C60 was different from that of monolayer film. In the spectra of dilayer film, when m/z <600, few peaks were found; when 600< m/z <720, the spectra had the characteristic fragmentary spectra of pure C60; when m/z >720, there was a broad peak. The above results demonstrated that laser MScan provide useful structural information in the study of fullerene film.
    Development and Application of Chromatographic Gray Model(Ⅱ)——Establishment of Nonlinear Continuous Gray Model NLCGM(1,1) and Prediction Retention Behavior of Aromatic Hydrocarbons
    ZHANG Su-Ping, SUN Zhao-Lin, LENG Jing, ZHANG Xiao-Tong, ZHOU Shan-Hua
    1998, 19(10):  1581-1583. 
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    The deficiency of the traditional GM(1,1) model for solving the nonlinear problem is pointed out, and an improved model NLCGM(1,1) is proposed by means of gray theory. During establishing the model, the double fitting is introduced both to improve the accuracy of the prediction and to achieve the continuous model. The model has been successfully applied to study the relationship between the capacity factor (k') of 32 polycyclic and monocyclic aromatic hydrocarbons and the composition of mobile phase(φ) in high performance liquid phase chromatography, and good results are obtained. In conclusion, there are three advantages for NLCGM(1,1) model. (1) Capacity factor can be predicted at any composition of mobile phase because the independent variable of the gray model can change continuously. (2) The precision of NLCGM(1,1) is higher than that of the traditional GM(1,1). (3) The traditional GM(1,1) is the special case of NLCGM(1,1). Therefore, the establishment of NLCGM(1,1) broadens the applied range of gray model.
    Oxygen Carrier Based on Immobilized Hemoglobin(Ⅱ)——Hemoglobin Covalently Bond to Periodate Oxycellulose
    KONG De-Ling, JIA Yong-Hui, YU Yao-Ting, TONG Ming-Rong, Wang Zi-Hui
    1998, 19(10):  1584-1588. 
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    Cellulose can be easily oxidized to oxycellulose with periodic acid, which can serve as a carrier for the immobilization of hemoglobin(Hb) acting like a bionic gill, to extract oxygen from sea water, which may provide a source of oxygen for human life support in an undersea environment. The objective of the present paper is to study the possibility of using modified cellulose derivatives as a carrier to immobilize a high amount of Hb.
    Studies on the Reaction of 1-Benzoyl-1-methylthiomethanol with Thioureas and Arylamines
    ZOU Jian-Ping, LIU Xian-Jun, XU Yong, LU Zhong-E
    1998, 19(10):  1589-1592. 
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    1-Benzoyl-1-methylthiomethanol(2) can react with thiourea(3a) and arylthioureas( 3b_3i ) in the slightly acidic medium to afford 5-phenylimidazolidine-2-thione-4-one(4a) and 1-aryl-5-phenylimidazolidine-2-thione-4-ones(4b_4i). On the other hand, when compound 2 was refluxed with arylamines in the slightly alkaline medium, 2-arylamino-2-methylthioacetophenones(6a_6f) can be obtained. Their structures are confirmed by X-ray, IR, 1H NMR, MSand elemental analysis.
    Paramagnetic Metal Chelate Complexes of DTPA Modified by Aminobenzoic Acid and Their NMR T1 Relaxivitives
    WEI Jun-Fa, ZHUO Ren-Xi
    1998, 19(10):  1593-1596. 
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    Two new DTPA-diamide derivatives bearing two aromatic moieties have been obtained by a modification of DTPA(diethylenetriaminepentaacetic acid) with p- and o- aminobenzoic acid. Their gadolinium, ytterbium, and iron complexes have been synthesized and some of them were examined for the role as the contrast agents for magnetic resonance imaging. The results show that the NMR T1 relaxivitives(R1) for Gd(Ⅲ) DTPA B4ABA2- and Gd(Ⅲ) DTPA B2ABA2- in water solutions are 5.5 and 5.4 L·mmol-1 ·s-1, respectively, which are higher than that of their parent complex, GdDTPA2-.
    Synthesis and Biological Activities of O-(1-Methylthioethylieneamino)phosphoramidates
    XING Xiao-Dong, TANG Guo-Zhi, XUE Bing, ZHANG Shu-Kui
    1998, 19(10):  1597-1601. 
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    Thirty title compounds were synthesized. The structures were identified by EA, IR, 1H NMRand MS, Many of these compounds demonstrate fungicidal, herbicidal and insecticidal activities by bioassay.
    Progress in Enzymatic Syntheses of Peptides and Peptide Derivatives in Organic Solvents
    XING Guo-Wen, YE Yun-Hua, LI Chong-Xi
    1998, 19(10):  1602-1607. 
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    More attention has been focused on the enzymatic reaction in organic solvents in recent years. In this paper, syntheses of peptides and peptide derivatives containing unnatural constituent catalyzed by proteases and lipase were introduced. The influence of reaction conditions on the enzymatic synthesis and its application to the preparation of cyclopeptide and polypeptide were reviewed. The study of relationship between enzyme activity and its structure through modern spectroscopy was also discussed.
    Microwave Assisting Solid Phase Organic Reaction Monitored by FTIR
    YU Ai-Ming, ZHANG Zheng-Pu, YANG Hua-Zheng, ZHANG Chun-Xiang, LIU Zhun
    1998, 19(10):  1608-1610. 
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    Microwave assisting the addition reaction of Wang resin bound secondary amine 1 and isocyanate was carried out for the first time. The reaction time course was determined by analyzing FTIRspectra obtained using the improved KBr pellet method by grinding down the resin beads prior to recording. The results showed that the reaction assisted by microwave was accomplished only in 12min, while the reaction without microwave was completed in 210min.
    Microenvironmental Effects on the Photochemical and Photophysical Processes of Long Chain Coumarin Esters
    DU Da-Ming, WANG Yong-Mei, MENG Ji-Ben
    1998, 19(10):  1611-1613. 
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    The photochemical reactions and photophysics of long chain coumarin esters have been investigated. In dioxane water(DX H2O) solvent mixture, long chain 4-methyl-7-hydroxycoumarin hexadecanate and octadecanate form aggregates forced by the hydrophobic effect. The photochemical reactions of this two long chain coumarin esters gave exclusively anti-HTdimer in 75% and 90% yields respectively in dioxane-water(volume ratio 1:2) solvent mixture. The excimer formation and the acceleration of photochemical reaction were ascribed to the hydrophobic effect and the changes of microenvironment.
    A Simple Approach to Highly Stereoselective Synthesis of β,γ-trans-γ-Butyrolactones
    CHEN Ya-Li, DING Wei-Yu
    1998, 19(10):  1614-1616. 
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    Asimple approach to highly stereoselective synthesis of trans-β-methoxycarbonyl γ-aryl-γ-butyrolactones(5a—5c) is reported. Methoxycarbonylmethyltriphenylarsonium bromide(1) in dimethyl ethylene glycol was reacted with 2,2-dimethyl-1,3-dioxa-5-p-methoxybenzal-4,6-dione(2a) in the presence of K2CO3 and trace of water at room temperature, to give trans-β-methoxycarbonyl-γ-p-methoxyphenyl-γ-butyrolactone(5a) with 64% yield, whereas 1,2-cis cyclopropane derivatives(3b and 3c) were isolated when started from 2b or 2c, under same conditions. The γ-butyrolactones 5b or 5c were obtained with 62% and 57% yields when compounds 3b or 3c was further heated in acetone water. The structures of 5a—5c were established on the basis of IR, 1Hand 13 C NMR, MSand elemental analyses, and their configurations were assigned via 2Dproton NOESYspectrum of compound 5c.
    A Facile Method for the Synthesis of 4-Amino-5-hydrocarbon-2,4-dihydro-3H-1,2,4-triazole-3-thione Schiff Bases
    WU Tai-Xing, LI Zhong-Jie, ZHAO Jin-Cai
    1998, 19(10):  1617-1619. 
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    In this paper, a facile method is reported for synthesis of the titled compounds by using glacial acetic acid as solvent and catalyst and 91 analogous Schiff bases were synthesized. The method exhibits many advantages such as simple procedures, fast reaction and easy purification of products. The causes of many advantages in the method are discussed and a possible mechanism of mass dissociation is given.
    Synthesis and Biological Activity of Biscyano Substituted Acyclic Ketene Aminals Containing2-Chloro-5-pyridylmethyl Group
    ZHAO Yi-Gang, HUANG Run-Qiu, CHENG Mu-Ru, LI Hui-Ying, CHENG Jun-Ran
    1998, 19(10):  1620-1622. 
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    In this paper, 2-cyano-3-(2-chloro-5-pyridylmethyl)amino-3-methylthioacrylonitrile 9 was synthesized. By the reaction of 9 as an intermediate with amines, nineteen new biscyano substituted acyclic ketene aminals containing 2-chloro-5-pyridylmethyl group were prepared. When 9 reacted with hydrazine, the corresponding cyclic compounds 10p was obtained. Preliminary bioassays show that 9 has a potential activity against aphid and the compounds 10a, 10f, 10g and 10r in this series have a good herbicidal activity.
    Synthesis of C60-Lucine Derivative C66NH13 and Its Theoretical Studies
    CHEN Zhong-Fang, PAN Yin-Ming, MA Ke-Qin, LI Fang-Xing, WANG Hai-Xiang, ZHAO Xue-Zhuang, Tang Ao-Qing, Feng Ji-Kang
    1998, 19(10):  1623-1626. 
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    1,3-Dipolar cycloaddition of azomethine ylide prepared via the reaction between lucine and aldehyde to C60 gave rise to a new C60-pyrrolidine derivative C66 NH13. The molecular structure was identified and characterized by FTIR, UV Vis, 1H NMR, LD TOFMSand elementary analysis. Semiempirical method AM1 was employed to study the structures of the two possible isomers [6,6] and [6,5] isomers. The calculation results indicate that [6,6] isomer is more stable than[6,5] isomer, and both isomers have C1 symmetry. The electronic spectra of both isomers were caculated based on the optimized geometries, and the calculated spectrum of [6,6] isomer is in good agreement with our experimental results, which also indicates that [6,6] isomer was obtained in our experiment. The reason for red shift of the spectra has also been discussed theoretically.
    Theoretical Studies on the Electronic Structure and Electronic Spectra of C120NH
    TIAN Wei-Quan, FENG Ji-Kang, REN Ai-Min, GE Mao-Fa, HUANG Xu-Ri, LI Zhi-Ru, SUN Jia-Zhong
    1998, 19(10):  1627-1631. 
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    The double-cage compound C120 NHwas studied by INDOseries. The results suggested that the formation of C120 NHreduce the angle constraint at the three-membered ring of imino in C60 NH, thereby, the C120 NHis stable. The direct connection of the two C60 cages rendered the two cages interact weakly each other. Natom also has a relatively strong capability of capturing the proton, and has somewhat selectivity. The spectra of C120 NHwas analogous to those of parent C60 and its isoelectronic dimer C120 Oand C120 CH2.
    Studies on the Quantitative Structure-property Relationship of Perylene-3,4,9,10-tetracarboxylic Acid Diimide Series
    PAN Jin-Hong, HUANG Zhong-Ping, CAI Guo-Qiang, YU Qing-Sen, ZONG Han-Xing
    1998, 19(10):  1632-1635. 
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    The stable geometries of derivatives of perylene-3,4,9,10-tetracarboxylic acid diimide have been obtained by AM1 and CNDO. The optimized geometries being contrasted with those in the solid crystals, compounds 3—5 exist in the planar structures with a higher bonding energy, which leads to the more effective packing of molecules. The linear relationship between the photosensitivity and the excitation energy of the N,N'-substituted diimide derivatives, and between the photosensitivity and the hole injection efficiency from the CGLto the CTLof the bisarylimidazole derivatives have been studied by the least square fitting method. The correlation coefficient of the former is greater than 0.95, and that of the latter is greater than 0.97. The results reveal that the two steps of photoelectric transformation have different effect on the photosensitivity. The electron excitation energy occupies the first position in the N,N'-substituted diimide derivatives, while the hole injection efficiency occupies the first position in the bisarylimidazole derivatives.
    A New Algorithm for Variational Quantum Monte Carlo Method
    HUANG Hong-Xin, CAO Ze-Xing
    1998, 19(10):  1636-1639. 
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    Anew algorithm of the variational quantum Monte Carlo(VMC) calculations, called the minimum variance(MV) method, is reported in this paper. This algorithm takes the internal structure of a local energy as starting point, and directly reduces its fluctuation in order to make the variance decrease to the minimum. An analytical expression of the local energy is presented.
    Raman Spectroscopic Studies on Coadsorption of Thiourea in the Nitric Acid Medium
    ZHONG Qi-Ling, LIU Feng-Ming, ZOU Dao-Wen, SHI Cai-Hui, XIE Yong, TIAN Zhong-Qun
    1998, 19(10):  1640-1644. 
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    The coadsorption of thiourea(TU) with NO3- in aqueous HNO3 was studied by using normal Raman spectroscopy(NRS), surface enhanced Raman scattering spectroscopy(SERS) and time resolved SERS(TRSERS). It was found that TUis chemically adsorbed on the surface of silver electrode via S, and NO3- can be induced by TUand coadsorbed on the electrode through the protonated amino of TUin the solution containing HNO3. The experimental results show that, at the potentials more positive than -0.6 V, TUis vertically adsorbed on the surface, while when the electrode potential goes negatively it gradually tends to tilt, even flat. Acomparative study on the stability of TUadsorbed on the silver surface in the medium of HNO3 and HClO4 respectively was carried out. It indicates that TUis more stable in aqueous HNO3 than in aqueous HClO4 at the relatively negative potentials(<-0.8 V), consequentially, the SERSsignal of TUcan still be detected in aqueous HNO3 at the potential of -2.0 Vwhile it is out of detection even at -1.4 Vin the latter medium. The origin has been discussed in detail in this paper.
    Studies on Preparation of Supported Cobalt-molybdenum Nitrides and Their Catalytic Behaviour for Pyridine HDN
    QI Xing-Yi, XIONG Guang, YANG Shu-Wu, XIN Qin
    1998, 19(10):  1645-1649. 
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    γ Alumina supported bi(mono)metallic transition metal nitrides were prepared respectively with 12 phosphomolybdic acid plus cobalt nitrate(denoted as CoMoN-Ⅰ and CoMoN-Ⅱ related with the precursor of the nitride, CoMoN-Ⅰ, calcined at 773 Kfor 6 h before nitriding), ammonium heptamolybdate plus cobalt nitrate(denoted as CoMoN-Ⅲ), and only ammonium heptamolybdate(denoted as MoN-Ⅳ) as the precursor active phases, using temperature programmed reduction with NH3, and characterized with BET, XRD, XPS, H2-TPDand Raman. Pyridine was selected as a model substrate in order to evaluate the HDNcatalytic activity of nitrides synthesized above. It was found that CoMoN-Ⅰ possesses conspicuously high pyridine HDNactivity as compared to that of CoMoN-Ⅱ, CoMoN-Ⅲ and MoN-Ⅳ.
    Intramolecular Hydrogen Bond Between Aromatic Hydrogen and Coordinated Sulfur Atom(sp2C-H…S)
    SHI Ji-Cheng, WEN Ting-Bin, LI Wen-Jie, WU Da-Xu, ZHENG Yu, LIU Qiu-Tian, Kang Bei-Sheng
    1998, 19(10):  1650-1653. 
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    Weak interaction between the H16 atom of aromatic hydrocarbon and the coordinated S2 atom, a new type of hydrogen bond sp2 C—H…S, has been suggested in explaining the phenomenon of the 1H NMR H16 peak of the compound(Et4N)2 Pd 2(mp)2(Hmp)2 (H2mp=2-mercaptophenol) appearing at δ 8.79 which is 1.7 lower than the expected value δ 7.1. The distances of C16…S2(0.361 pm) and H16…S2(0.295 pm) lowing the sum of the van der Waals radii(0.325 pm) for the corresponding atoms, respectively, demonstrates the existence of the hydrogen bond. In addition, it has been observed that the C Hof aromatic hydrocarbon shifts to 2998 cm-1 resulting from the sp2 C H…Shydrogen interaction. Comparison with the structure of the analogues compound Pd2(PPh3)2(Hmp)2Cl2 and the remaining of the O—H…Oand C—H…Shydrogen bonds even in DMSOsuggest that the torsion angle between the phenyl linking to the bridging sulfur atom and Pd2S2 plane deviated from 90° may be contributed partially from the C H…Shydrogen bonding.
    The Ab initio Study of Molecular Water Adsorption on Cu(100)
    FU Ai-Ping, FENG Da-Cheng, DENG Cong-Hao
    1998, 19(10):  1654-1658. 
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    Ab initio molecular orbital method is used to theoretically investigate the interactions of water with the different sites of Cu(100) surface in this paper. Cu 5 cluster is used to simulate the surface, the adsorption energies and geometries in different directions are calculated at lanl1dz basis set level. The results show that water bonds to the surface through the oxygen atom, it prefers to adsorb on top site with the adsorption energy 70 kJ/mol and the equilibrium Cu Odistance 0.213 nm, and hydrogen atoms are far away from the surface. Giving no consideration of the d orbitals of oxygen atom, the optimum structure is the water plane normal to the surface, H2Otilts of 50° are found to require small amount of energy. When the d orbitals of oxygen atom is taken into account, the calculated structure of adsorption H2Omonomer with an inclined molecular axis about 50° is in agreement with the experimental results. Also the effect of charge on the adsorption system is discussed. The results indicate that on the surface with positive charges, the interactions between water and surface are strengthened, the charge transfer from the water to the surface increases, and Cu Oequilibrium distance decreases; On the surface with a negative charge, the results are opposite, the structure with Hnear the surface is the stable one.
    Ab Initio Study on the Electronic Structures and the Spectra Properties of the Mo2X4(X＝S,O)Clusters
    ZHANG Yong-Fan, WU Li-Ming, LI Jun-Qian, HUANG Zun-Xing, HU Jia-Ming, ZHOU Li-Xin
    1998, 19(10):  1659-1665. 
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    Using ab initio method, the electronic structures of the clusters containing the cis (Ⅰ)/ trans (Ⅰ') Mo2S4 and Mo 2O4(Ⅱ) core have been studied. The (4s4p2d) pseudopotential basis set of Mo atom has been chosen for the calculations of the dinuclear molybdenum clusters by optimizing the geometry of cluster(Ⅰ). The chemical bondings of three clusters are discussed by using the natural bond orbital(NBO) method and comparing with the similar dinuclear tungsten clusters. The IRvibration frequencies of three clusters have been calculated, the main absorption bands are assigned and compared with each other. The electronic spectra have been calculated using the CISmethod, it is shown that the lowest excited states of three clusters are the result from two transitions, σ(Mo-Mo)→ π (Mo-Xt*) (X=S,O) and σ(Mo-Mo)→ σ(Mo-Mo*), and the contribution of the former are greater.
    Studies of Methane Reforming with Carbon Dioxide on Hexaaluminates
    JI Min, BI Ying-Li, ZHEN Kai-Ji, WU Yue
    1998, 19(10):  1666-1670. 
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    In this paper, a series of Sr1-x Lax NiAl11 O19 catalysts were synthesized and their chemical and physical properties were investigated by XRD, UV-DRS, H2-O2 titration, TPRand Py-IRtechniques. The experimental results show that the Sr1-x Lax NiAl11O19 catalysts have a magnetoplumbite structure and Ni ion is shared between tetrahedral and octahedral sites of the spinel blocks, and the amount of nickel ions in the tetrahedral environment increases with the increase of x value in Sr1-xLax NiAl11O19.
    Electrochemical Properties and Electronic Energy Level Structure of Os(Ⅱ) Complexes
    WU Fang, TIAN Wen-Jing, ZHANG Hou-Yu, MA Yu-Guang, SHEN Jia-Cong, ZHI Zhi-Ming
    1998, 19(10):  1671-1673. 
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    The effects of molecular structure on the electrochemical properties and the electronic structure of four Os(Ⅱ) complexes have been explored by cyclic voltammetry and fluorescence spectra. The results indicate that the oxidation and reduction properties and the electronic energy level structure of the complexes can be changed by either introducing different substituents into the bipyridine ligand or replacing the bipyridine ligand with phenanthroline. The above conclusion were confirmed by the photospectroscopy measurements.
    Ab Initio Calculation on Molecule Interaction Between Benzene Halide with Water
    ZHAO Bao-Zhong, CHU Bei, SU Zhong-Min, WANG Rong-Shun
    1998, 19(10):  1674-1676. 
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    The molecule interactions of benzene halide with water were investigated with the ab initio calculation. The results show that the interaction of different atoms in benzene halide with water is not the same, and that the interaction of the hydrogen in benzene halide with water is bigger than that of the carbon atom bonding with halogen. The change of halogen atom has a key effect on the interactions of other atoms in benzene halide with water.
    Studies on the CrF3/AlF3 Catalyst for Synthesis of HFC-134a as a Substitute for CFC-12(V)——Interaction of CrF3 and AlF3
    LU Jian, SHI Lei, LI Hui-Li, PENG Shao-Yi
    1998, 19(10):  1677-1679. 
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    The effects of Cr 3+ content in CrF3/AlF3 catalysts on activity for synthesis of HF 134a from reaction of HCFC133a with HFwere investigated. FTIR, EPRand XPShave been employed to characterize the CrF3/AlF3 catalysts. The results show that CrF3 existed in a monolayer dispersion where the interaction between CrF3 and AlF3 support became stronger when Cr 3+ content less than1%. The CrF3/AlF3 catalyst with 0.1% Cr 3+ exhibits the highest turnover frequency. The residual oxygen in the catalyst forms surface active species of CrAlOm Fn from the interaction of CrF3 and AlF3, which is the cause of high selectivity to HFC-134a in F/Cl exchange reaction.
    The Curing Theory of Af Type Free Radical Homopolymerization(Ⅱ)——The Structure Parameters of Polymer Network
    WANG Hai-Jun, LU Zhong-Yuan, HUANG Xu-Ri, LI Ze-Sheng
    1998, 19(10):  1680-1683. 
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    By means of the polymer statistical theory, the Af type free radical homopolymerization reaction is investigated to give the number of chains, chain nodes, the average length for the elastic effective chains and the corresponding quantities for the dangling chains. Furthermore, the modulus of elasticity, the number of effective crosslinking points, the number and weight-fraction of elastic chains are also deduced. These results are important for revealing the mechanical property of the network polymers.
    The Coagulation and Phenyl Stacks on the Surfaces of Polystyrene Microparticles
    XU Wei, HUA Zhong-Yi
    1998, 19(10):  1684-1688. 
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    The scanning tunneling microscopy(STM) was used to investigate polystyrene microparticles. The STMimages show that the polystyrene surfaces have different modes of coagulation. In some regions, the polymer chains are found to be orderly packed without entanglement. In some proper case, the phenyl groups in the same chain can stack up as a parallel displaced(PD) structure, similar to that predicted for benzene dimers. The polystyrene microparticles swelled with a mount of benzene was also investigated, the polymer chains with helical structures as well as the polymer chains with distortion can be observed. The existence of the orderly packed polymer chains and phenyl stacks may be due to the fact that styrene monomer stack in an orderly fashion in some parts within micromicellae.
    Separation of Fructose from Fructose-Glucose Syrup Using Macroporous Dihydroxyborylated Polystyrene Resin
    GE Yu-Bin, SUN Wen-Tian, WANG Shu-Yan, ZHOU Hui, LI Wei
    1998, 19(10):  1689-1692. 
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    Macroporous dihydroxyborylated polystyrene resin was prepared in this paper through coupling m-aminophenylboronic acid and macroporous aminopolystyrene by diazotization. Some factors which influence the absorbing ability for fructose of the resin were investigated. Some factors which affect the elution curve were also studied. Fructose was successfully separated from the mixture of glucose and fructose when using the resin as the separating medium. The purity of the obtained fructose syrup was 99%, with a concentration of 106 mg/mL. This resin may potentially be used in industry for separating glucose and fructose.
    Synthesis of Poly-γ-mercaptopropylsiloxane Palladium(0)Complex and Its Catalytic Properties
    CAI Ming-Zhong, SONG Cai-Sheng
    1998, 19(10):  1693-1696. 
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    Asilica-supported poly γ-mercaptopropylsiloxane palladium(0) complex was prepared from γ-mercaptopropyltriethoxysilane and fume silica via hydrolysis, followed by treatment with palladium chloride in acetone and then the reduction with hydrazine hydrate in ethanol. It was found that the title complex is an efficient catalyst for Heck arylation of acrylamide and butyl acrylate. This polymeric palladium(0) catalyst is stable and can be reused without noticeable loss of activity.
    Synthesis of 3-Methoxydiphenylamine-4-diazonium Salt and Its Photo- and Thermal Decomposition
    ZHAO Chao, CAO Wei-Xiao
    1998, 19(10):  1697-1699. 
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    The 3-methoxydiphenylamine-4-diazonium salt(MDDS) was synthesized using resorcinol and aniline as start materials via six steps with total yield of 36%. The photochemical and thermal decomposition of MDDShave been investigated. It is shown that MDDSexhibit excellent thermostabilities as well as high photosensitive behavior. The thermal decomposition temperature was determined to be 178 ℃ which is about 31 ℃ beyond that of diphenylamine-4-diazonium salt(DS). The thermal decomposition of MDDSin aqueous or ethanol solution was also reported.
    Controlled Sequential Radical Copolymerization of Styrene and Butyl Methacrylate
    ZOU You-Si, QIU Zhi-Ping, DAI Li-Zong
    1998, 19(10):  1700-1702. 
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    The application of atom transfer radical polymerization for the synthesis of controlled block copolymer of styrene and butyl methacrylate was discribed in this paper. For instance, butylmethacrylate was first polymerized by using 1-PECl, CuCl and bipyridine in a molar ratio of l:1:2 at 120 ℃ for 2 h, the bulk polymerization proceeded to about 96% conversion. When styrene was subsequently added to the controlled polybutyl methacrylate synthesized as described above and polymerized at the same temperature for 5 h, the block copolymers of BMAand Swith predicted molecular weight(1×104～4×104) and narrower molecular weight distribution(1.1～1.5) were obtained. When the first monomer was changed to styrene, it needed more time to get high conversion.
    The Synthesis of Soluble Poly (p-phenylene vinylene) Derivatives
    WANG Jian-Ying, LI Yin-Kui, HU Wen-Xiang, LONG Yong-Fu
    1998, 19(10):  1703-1705. 
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    Poly(2-methoxy-5-hexyloxy-p-phenylene vinylene) and poly(2-methoxy-5-nonyloxy-p-phenylene vinylene) were synthesized through dehydrochlorination with p-methoxy phenol as raw materials. The effect of solvents and substituents on polymerization and polymer solubility was discussed. The structure of polymers was identified by UV/Vis, IR and 1H NMR.
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