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    24 December 2001, Volume 22 Issue 12
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    Articles
    Hydrothermal Synthesis and Crystal Structure of Na2[(VO)12O6B18O39(OH)3]·(11H3O)·4H2O
    ZHANG LiRong, LI GuangHua, SHI Zhan, FENG ShouHua
    2001, 22(12):  1963-1966. 
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    Ahydrothermal reaction of V2O5, Na2B4O7·10H2O, NaH2PO4·2H2O, en, H2Oin a molar ratio of 0.5:1:1:2.24:111 gives a brown crystal Na2[(VO)12O6B18O39(OH)3] ·(11H3O) · 4H2O. It crystallizes in a monoclinic system with space group P2 1/n and unit cell parameters a=1.38970(8) nm, b=1.66159(9) nm, c=1.42748(8) nm, β=95.6910(10)°, Z=4, R=0.0549. The structure consists of a [(VO)12O6B18O39(OH)3]13- cluster which is connected by Na+ through Na——Oionic bond to form a 2dimensional layered structure. The [(VO)12O6B18O39(OH)3]13- cluster consists of a puckered B18O39(OH)3 ring sandwiched between two triangles of six edgesharing vanadium atoms. The oxidation states of vanadium in the compound are V(Ⅳ) and V(Ⅴ) in a molar ratio of 5:1. Other characterizations are also described.
    Synthesis and Spectroscopic and Structural Characterization of Racemic Ammonium Dimeric(malato)dioxomolybdenum
    YAN WenBin ZHOU ZhaoHui, ZHANG Hui, WAN HuiLin, Cai QiRui
    2001, 22(12):  1967-1970. 
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    The complex (NH4)4[Mo∧O2(S,SHmal)2]·[MoΔO2(R,RHmal)2] was prepared from the reaction of ammonium molybdate and R,Smalic acid at pH=2——3. It was characterized by elementary analysis, conductivity measurement, optical rotation, IRand Xray diffraction. The complex crystallizes in monoclinic space group P21/a with unit cell parameters: a=0.8061(2) nm, b=1.3286(2) nm, c=1.3232(2) nm, β=91.82(2)°, V=1.4164(9) nm3, Z=2, Dc=2.008 g·cm-3, F(000)=864, μ=9.700 cm-1 for 1902 reflections with I≥3σ(I). The molybdenum atom is coordinated by two bidentate homochiral malic acid in distorted octahedron, while the βcarboxyl groups remain uncomplexed. The crystal contains two isolated monomeric malatomolybdates(Ⅵ) anions in the configurations of ∧S,S and ΔR,R. The two enantiomeric anions result in the formation of racemic compound. There is no evidence for the other diastereoisomers like (NH4)2[Mo∧O2(R,SHmal)2], (NH4)2[MoΔO2(R,SHmal)2], (NH4)2[Mo∧O2(R,RHmal)2] and (NH4)2[MoΔO2(S,SHmal)2] in this experiment.
    Dense A-type Zeolite Membrane Synthesized by Seeding
    LIN HaiQiang, YANG LeFu, WAN HuiLin
    2001, 22(12):  1971-1975. 
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    The synthesis of Atype zeolite membranes on porous α Al2O3 supports via the method of seeding plus secondary hydrothermal crystallization has been studied. The seed layers, which were prepared from colloidal Atype zeolite synthesized from the reaction mixture of n[(TMA)2O]: n (SiO2): n (Al2O3): n (Na2O): n (H2O)=13.4:11.25:1.8:0.3:700, were treated by steam of ammonia to inhibit the formation of cracks when dried. Compact zeolite membranes constituted with multipletwined zeolite crystals were accessed by hydrothermal growth of seed layers in the reaction sol of n (Na2O): n (Al2O3): n (SiO2): n (H2O)=3:1:1:800. In highly alkaline hydrothermal solutions, seed layers tended to dissolve and loose zeolite membranes with many defects were obtained. The gas permeanbility on Atype zeolite membrane dried at 393 K, in which water molecular still inhabited the zeolitic channels, was quite low, suggesting that the membrane was close to free of defects. Defects were formed mainly due to different thermal expansion coefficients between α Al2O3 support and zeolite membrane when the calcinations at 823 Kwas carried out to free the channel of membrane zeolites.
    Studies of Soluble Human Catalytic Antibody with Glutathione Peroxidase Activity
    QI XiaoJie, WANG Lin, FANG Fang, YAN XiYun, DING Lan, ZHAO DaQing, NI JiaZuan
    2001, 22(12):  1976-1978. 
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    By screening the phagedisplayed human single chain antibody library, we have got the specific single chain antibody bound to GSHSDNPbutyl ester as the hapten. The tertiary structure of the protein was analyzed with the aid of computer, and the results showed the CDR3 region located on the surface of the antibody. The soluble antibody was expressed in E.coli. and the active site serine was converted into selenocysteine with the chemical modifying method, which resulted in the catalytic antibody with GPx activity of 80 U/μmol. Furthermore, the same PingPong mechanism as the natural GPx was observed when the kinetic behavior of the antibody was studied.
    Mechanism of Heavy Metal Ions on α-Amylase Activity from Porcine Pancreas
    HONG FaShui, WANG XueFeng, WU Kang, SHEN SongDong, SU GuoXing, PAN XinFa
    2001, 22(12):  1979-1983. 
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    The activity of αamylase from porcine pancreas was enhanced under the treatment by Ce3+, Cd2+ and Pb2+ at a low concentration (0.5-5 μmol/L) , but was inhibited by Ce3+, Cd2+ and Pb2+ at a high concentration(4 or 5 μmol/Labove). Ce3+, Cd2+ and Pb2+ at a high concentration could competitively displace Ca2+ from αamylase. The equilibrium dialysis demonstrated that αamylase have five Ca2+binding sites with different affinities. The fluorescence titration showed that Ce3+, Cd2+ and Pb2+ are not only bound to Ca2+binding sites, but also bound to other sites of αamylase, and resulted in the αamylase conformational changes.
    Structural Study of LiNi1-xAlxO2(x=0-1.0) Solid Solution via X-ray Diffraction
    GONG Jie, WANG Chun Zhong, ZONG Zhan Guo, CHEN Gang
    2001, 22(12):  1984-1986. 
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    This paper covers the results of structural study of solid solution of LiNi 1-x Alx O2( x=0-10) via Xray diffraction. It is observed that the single phase solid solution with α NaFeO2 structure is formed for the whole concentration range(0≤x≤1). Lattice parameter, a decreased, c/a increased, and cell volume decreased with the increasing of Al concentration. The layered characteristics becomes more and more strong with the increasing of Al concentration.
    The Assembly of Gold Nanoparticulate Monolayer onto Mica Substrate
    GUO Wei, WEI Li, ZHANG XinTong, BAI YuBai
    2001, 22(12):  1987-1989. 
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    Gold nanoparticles, prepared by the Frens method, have been electrostatically assemblied onto mica substrates treated with different concentration of MnCl2 solution. The assemblies have been investigated by means of atomic force microscopy(AFM). The immersing time of bare mica in Mn2+ solution and the concentration of Mn2+ solution both have significant effect on the assembled process of gold nanoparticulate monolayer. The coverage of gold particles shows periodical evolution on the immersing time of mica in MnCl2 solution. The higher is the concentration of MnCl2, the shorter is the time to attain maximum coverage. An ionexchanged and layerdissociated mechanism is put forth to explain the experimental results above.
    Phase Equilibrium of the Ternary System La(ClO4)3-BAPOAP-H2O(30 ℃) and the Syntheses and Characterization of La2(BAPOAP)3(ClO4)6
    TANG ZongXun, LIANG HongBin, CUI Bing
    2001, 22(12):  1990-1992. 
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    The phase equilibrium of the ternary system La(ClO4)3BAPOAPH2Oat 30 ℃ was studied by means of the isothermal solubility method. The incongruent compound, La2(BAPOAP)3(ClO4)6, was discovered. Based on the results of phase equilibrium, the series compounds Ln2(BAPOAP)3(ClO4)6 were synthesized and characterized by chemical analyses, elemental analyses, IRspectra and TGDTGanalyses.
    Aggregation and π-π Coordination of Tetra[4-carboxymethoxyphenyl] Porphyrin Metal Complex(M=Ni, Cu, Zn) and the Vitro Antitumor Activity of Dibutyltin(Ⅳ) Tetra[4-carboxymethoxyphenyl]porphyrinate
    HAN GaoYi, YANG Pin
    2001, 22(12):  1993-1995. 
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    Tetra[4carboxymethoxyphenyl]porphyrin copper(Ⅱ), nickel(Ⅱ), zinc(Ⅱ) complex and their dibutyltin(Ⅳ) ester derivatives have been synthesized and characterized. The equilibrium constants of the aggregation of the metal porphyrin and the equilibrium constant of the π-π coordination with phenothoroline have been measured by using UVVis titration method. The results show that the equilibrium constants decrease in the order of KCuP> KNiP> KZnP. The vitro antitumor activities of the dibutyltin(Ⅳ) metal porphyrinate has some relation with the ability of aggregation and coordination with ligand of the metal porphyrin.
    Separation and Determination of Beryllium(Ⅱ), Chromium(Ⅲ), Copper(Ⅱ), Iron(Ⅱ) and Nickel(Ⅱ) with Two Colour Reagents of Chromotrope 2C and TAN by RP-HPLC
    LIU ShaoPu, PENG JingDong, DENG ChuanYue
    2001, 22(12):  1996-1999. 
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    A RP HPLCmethod for the separation and determination of beryllium(Ⅱ), chromium(Ⅲ), copper(Ⅱ), iron(Ⅱ) and nickel(Ⅱ) with chromotrope 2Cand TANchelates on a YWG ODScolumn by using methanol ethanol water(volume ratio is 35:5:60) containing5×10-5 mol/Lchromotrope 2C, 5×10-5 mol/L TANand acetate buffer solution(pH=50) as mobile phase and with spectrophotometric detection at 580 nm was developed. The method has a high sensitivity. The detection limits were 5 μg/mLfor beryllium(Ⅱ), 10 μg/mLfor chromium(Ⅲ), 10 μg/mLfor copper(Ⅱ), 20 μg/mLfor iron(Ⅱ) and 04 μg/mLfor nickel(Ⅱ). Under the optimum conditions most other metal ions do not interfere. The method can be applied to the simultaneous determination of trace amounts of beryllium, chromium, copper, iron and nickel in rice and flour samples.
    Spectroelectrochemistry Studies of Antitumor Antibiotics Daunomycin
    QU HaiYun, CHENG GuiFang, PENG HuiQi, HE PinGang, FANG YuZhi
    2001, 22(12):  2000-2004. 
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    The electrode process of antitumor daunomycin has been investigated by using in situ spectroelectrochemical techniques, with the aid of cyclic voltammetry and infrared spectrophotometry. Possible mechanisms of its reduction processes have been discussed where the concentration makes a critical effect. When the DRNconcentration is low, two successive one electron reduction steps are demonstrated, which was followed by an aglycon elimination reaction, and then, the product 7 deoxydaunomycinone received one electron to form 7 deoxysemidaunomycione free radical, such radicals can disproportionate or associate easily. But if high, only one electron reduction happened to get the corresponding semiquinone radicals, which can also associate rapidly.
    Chemiluminescence Detection of 10-16mol/L Level Co(Ⅱ) with Field-amplified Sample Injection in Capillary Electrophoresis
    LIU YanMing, LIU ErBao, CHENG JieKe 
    2001, 22(12):  2005-2007. 
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    Amethod of online ultrasensitive chemiluminescence detection with capillary electrophoresis for Co(Ⅱ) is reported. Using our newly developed capillary electrophoresis with chemiluminescence detection system and novel mixing mode of the reagents, the effects of fieldamplified sample injection on detection limits of metal ions were studied in detail. The subfmol/Llevel(0.13 fmol/L, 1.6 ymol) detection of cobalt ions in ultradilute solution was performed. The separation of fmol/Llevel Co(Ⅱ) and trace amounts of Ni(Ⅱ) was performed successfully.
    Molecularly Imprinted Polymer Monoliths Prepared in Capillaries by Photoinitiated in situ Polymerization for the Screening of Caffeine
    YAN LiuShui, WANG YiMing, WANG ZongHua, LUO GuoAn 
    2001, 22(12):  2008-2010. 
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    Anovel and simple method for the in situ preparation of monolithic molecularly imprinted flowthrough polymers is described. The polymers were prepared inside UVtransparent fused silica capillaries by photoinitiated polymerization of a mixture of caffeine as the template, methacrylic acid as the functional monomer , trimethylolpropane trimethacrylate as the crosslinking agent in the presence of a porogenic solvent consisting of toluene and isooctane . Scanning electron micrographs confirmed the presence of the clusters of globules separated by large pores on the monolithic structure. The effectiveness of the imprinted polymer monolithic column was demonstrated in microcolumn liquid chromatography(μHPLC)mode by the screening of caffeine from a mixture of four structural analogues, the resolution factor Rs of 2.57 and 2.97 for the separation of caffeine against theophylline and theobromine, respectively, were obtained, while the nonimprinted column showed no specific selectivity. It is considered that the template was effectively imprinted in monolithic polymer by photoinitiated in situ polymerization at a low temperature. Several factors such as the molar ratio of the functional monomer to the imprint molecule and polymerization time affecting the flowthrough properties of a MIPcolumn were also investigated. The results show that the obtained columns exhibit higher resolution and column efficiency against the structural analogues than do columns packed with MIPprepared by bulk polymerization and columns packed with continuous molecularly imprinted polymer rod prepared by in stiu method.
    Determination of Phenolic Compounds in Red Wine by Capillary Zone Electrophoresis with Electrochemical Detection
    CAO YuHua, ZHANG Xin, FANG YuZhi, YE JianNong
    2001, 22(12):  2011-2013. 
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    Asimultaneous determination of (-) epictechin, (+) catechin, gentisic acid, ferulic acid, quercetin and gallic acid in red wine by capillary zone electrophoresis with electrochemical detection(CE ED) was reported. The effects of potential of working electrode, pHand concentration of running buffer, separation voltage and injection time on CE EDwere investigated. Under the optimum conditions, these six analytes could be separated in a 100 mmol/Lborate buffer(pH=924) within30 min. A 300 μm diameter carbon disk electrode has a good response at +085 V( vs . SCE) for all analytes. The responses were linear over two orders of magnitude with detection limit( S/N=3) ranged from 7×10-8 g/mLto 14×10-7 g/mLfor all six analytes. This method has been used for the determination of these analytes in red wine without enrichment, and the assay result was satisfactory.
    Studies on Synthesis and Anticancer Activity of Thiosemicarbazones
    HU WeiXiao, SUN Nan, YANG ZhongYu
    2001, 22(12):  2014-2017. 
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    Sixteen of thiosemicarbazone(Ⅰ) was synthesized. Hydrazine reacts with carbondisulfide and dimethyl sulfate in the presence of potassium hydroxide to form compound Ⅱ with yield 60. compound Ⅱ reacts with ketone or aldehyde to form compound Ⅲ. Compound Ⅲ reacts with Nsubstituted piperazine to form Ⅰ with yield 27-85. The structures of the compounds were comfirmed by IR, NMR, elemental analysis, and the results shows that the thiosemicarbazone with proper substituents has somewhat activity. These compounds are valuable ones for being studied further.
    Syntheses Studies of 6,6’-Dimethoxy-4,5,4’,5’-dimethenedioxy-2,2’-dimeth oxycarbonyl Biphenyl and Its
    GUO RuiYun, HE Juan, CHANG JunBao, CHEN RongFeng, XIE JingXi, GE YongHui, LIU YueQi
    2001, 22(12):  2018-2021. 
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    The present paper covered the syntheses of 6,6' dimethoxy 4,5,4',5' dimethenedioxy 2,2' dimethoxycabonyl biphenyl( βDDB) in higher yield with the gallic acid as the starting material by multi step synthesis: esterification, monomethylation, formation of the methylenedioxy derivative, nitration, reduction, Sandmeyer and Ullmann coupling reaction. Five of its derivatives have also been synthesized and four of them are new compounds. The structure of these compounds are confirmed by IR, 1HNMR, MSand EA. The resolution of βDDBwith HPLCgave two components. The configuration of the first component was assigned as Rby comparison of its CDspectrum. 258 positive cotton effect with that of Rdimethyl hexamethoxydiphenate, and the configuration of the second component thus obtained was assigned as Sby comparison of its CDspectrum 258 negative Cotton Effect.
    A Study of Catalytic Hydrogenation of Copolymer of PS-PB-PS(SBS) with Titanocenes
    XU ShanSheng, YANG Liu, YUAN Ke, WANG BaiQuan, ZHOU XiuZhong, LI Wei, HE Xiao Jin
    2001, 22(12):  2022-2025. 
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    Aseries of titanocenes[(C5H4R)2TiCl2, R=H(1), Me(2), C6H11 (3) and (C5H4R)2TiAr2, R=H, Ar=C6H5(4), p MeC6H4(5), m MeC6H4(6); R=Me, Ar=C6H5(7), p-MeC6H4(8); R=C6H11 , Ar=C6H5(9), p-MeC6H4(10)] were synthesized. The catalytic hydrogenation of SBScopolymer using these catalysts was studied.The effects of the types of catalyst, the amount of catalyst and the component ratio of catalyst were investigated and found that the SBSwas hydrogenated more than98 when the amount of catalyst was 0.001-0.003 mmol/g polymer. Among the catalysts, the ptolyltitanocene were synthesized. The catalytic hydrogenation of SBScopolymer using these catalysts was studied.The effects of the types of catalyst, the amount of catalyst and the component ratio of catalyst were investigated and found that the SBSwas hydrogenated more than 98 when the amount of catalyst was 0.001-0.003 mmol/g polymer. Among the catalysts, the ptolyltitanocene 8 gives the best result and is a promising catalyst system for catalytic hydrogenation of SBScopolymer.
    Recent Development in the Bioorganic Chemistry of Nitric Oxide
    LI Qian, ZHU XiaoQing, HE JiaQi, CHENG JinPei 
    2001, 22(12):  2026-2031. 
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    Recent developments in the bioorganic chemistry of nitric oxide(NO) are reviewed and the relationship of NO's physiological functions with its related chemical reactions is also discussed in this paper.
    The "Methyl Effect" in The Enantioselective Allylic Substitution Using Palladium/Chiral Pyridinylmethyl-oxazolines
    LI ZhiPeng, TANG FangYi, WU XinYan, ZHOU QiLin, Albert S. C. Chan
    2001, 22(12):  2032-2033. 
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    In this paper, two types of chiral ligands 1 and 2 containing pyridinyl moiety and oxazolines bridged by a methylene group were investigated in the palladium catalyzed substitution of 1,3 diphenyl 2 propenyl acetate with dimethyl malonate. Ligands 2, which have two methyl groups at the bridged methylene, gave higher enantioselectivities than their unsubstituted analogues 1. This "methyl effect" increased while the substituent on the C4 in the oxazoline ring was changed from benzyl to tert butyl. Despite of that the "methyl effect" was found in the palladium catalyzed enantioselective allylic substitution, it was obviously significant for assisting rational design of chiral ligands and catalysts in other asymmetric reaction.
    A Study of Tyrosine O-Phosphorylation via Atherton-Todd Reaction
    ZHAO Gang, LI YanMei, LUO ShiZhong, HAN Bo, ZHAO YuFen
    2001, 22(12):  2034-2036. 
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    The tyrosine Ophosphorylation via AthertonTodd reaction, which was a classical reaction for phosphorylation amines, was first studied in this paper. Reaction of BocTyrOCH3, which was selected as model substrate, with three dialkyl Hphosphonate diester in the presence of CCl4 and triethylamine produced the corresponding tyrosine Ophosphorylation products in a high yield(over 80). The reaction was conducted in anhydrous THFsolution and monitored by 31P NMRand TLC. Then reaction of BocTyrOCH3 with a complicated Hphosphonate diester, O-3'-acetylthymidin-5'-yl Oisopropyl Hphosphonate diester, also gave a good result and this would be an alternative approach for the synthesis of nucleotide Otyrosine (or tyrosine containing peptide) conjugate. Further, the successful Ophosphoration of three tyrosine containing protected dipeptides, BocTyrValOCH3, BocAlaTyrOCH3, BocTyrTyrOCH3, with diisopropyl Hphosphonate diester demonstrated the effectiveness of the method.
    Stereospecific Synthesis of Free Hydroxyl β-C-Glycosides in One Sstep
    WANG Wen Zhong, ZHANG PeiYing, Lü YiXian
    2001, 22(12):  2037-2039. 
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    Free aldopentoses and aldohexoses reacted respectively with (EtO)2P(O)CHNaCOAr to give the five stereospecific free hydroxyl β Cglycosides in one step. The reaction take place under a mild condition. The procedures are simple and convenient. The prices of starting materials are cheap. The method can be applied universally for aldopentoses and aldohexoses. The application scope of Wittig Horner reaction has also been expanded. The synthesis of free hydroxyl β Cglycosides from free aldoses directly using WittingHorner reaction has not been reported so far.
    Synthesis of Muscone Mediator 2,15-Hexadecanedione from Tetrahydrofolate Coenzyme Model
    BAI YinJuan, LU Lin Gang, SHI Zhen
    2001, 22(12):  2040-2041. 
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    Anew synthetic method of 2,15 hexadecanedione from imidazalium salt and di Grignard reagent is reported. Imidazalium salt was used as tetrahydrofolate coenzyme model at formic acid oxidation level and di Grignard reagent as a nucleophile to which one carbon unit was transferred, the biomimetic synthesis of 2,15 hexadecanedione, a precursor of 3 methylcyclopentadecanone(muscon), was successfully accomplished by using the addition hydrolysis reaction of imidazolium salt with di Grignard reagent.
    Study of the Solid State Reactions of Barbituric Acid and Aromatic Aldehyde
    LI GuiShen, LI JingCi, WANG Chun, FENG Shuo, LI XiaoLu
    2001, 22(12):  2042-2044. 
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    The knoevenagel condensation reaction of barbituric acid and aromatic aldehyde under ground and heated in solventless system was described. The reaction mechanism was also proposed. The structures of the products were identified by IR, 1HNMR, 13CNMRand UV. 5-Alkylidene barbituric acid was the only product in the two reaction systems.
    Design of a Novel Macrocyclic Sulfonamide Peptidomimetics and Synthesis of the Precursors
    ZHAO BaoXiang, Siegfried Blechert
    2001, 22(12):  2045-2047. 
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    Aroute of synthesis of a novel macrocyclic sulfonamide peptidomimetics via ring closing metathesis(RCM) has been designed. Allyl glutaric anhydride has been synthesized from commercially available diethyl allylmanolate and tert butyl acrylate by the Michael reaction and hydrolysis followed by decarboxylation and dehydration. Then, allyl hydrogen2allylglutarate, a precursor for RCM, has been prepared. The synthesis of N-allyl-ethoxycarbonyl-aminoethylsulfonyl amide, another precursor, has been accomplished from cystine.
    Studies on Irreversible Capacity Loss of Disordered Carbon Anode
    XIE ZhongWei, QU XiaoGuang, ZHU DongXia, GONG Jian, QU LunYu, XIE DeMin
    2001, 22(12):  2048-2051. 
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    The irreversible capacity loss that occurs during the first cycle in lithium ion rechargeable batteries was studied. The experimental results show that when a disordered carbon prepared from resole resins by pyrolysis was used as a anode, the irreversible capacity loss was related to not only the solvent decomposition to form Li2CO3 and to the compounds containing COOHgroups and CHgroups on the carbons surface, but also to the compounds containing CLi or OLi in the bulk of carbons.
    Theoretical Studies of the Chemisorption of CO on Metal Catalysts Under the effects of Promoters
    LIU YongDong, SUN RenAn, WANG ChangSheng
    2001, 22(12):  2052-2055. 
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    The calculations have been performed for model systems MCOMn+1(M=Ru, Rh, Pd; M1n+=Na+, K+, Mg2+) by Gaussian programs at the HF/LANL2DZlevel. The influences of C—Obond and its mechanism have been studied after the COadsorbed on the main group metal cation M1n+ promoted transition metal catalysts. And the products of COhydrogenation on these catalysts have been inferred. The calculations showed that the different interaction positions of the main group metal cation promoter and the various kinds of metal cation promoters both cause the changes of catalyst activity and selectivity. When M1n+ cations affect the COthrough the Oatom of CO, the C—Obond is weakened largely and the products of COhydrogenation over these catalysts will shift to hydrocarbons. When the M1n+ cations affect the COthrough the transition metal atom, the CObond is weakened slightly, so it is beneficial to form oxygenates. And there is no activity when M1n+ cations bonded on the side of CO. It can also be concluded that the main group metal cation with stronger ability to accept the electrons may be a better promoter.
    Long-range Electron Transfer in Peptides: Influence of Peptide Conformation and Side Chain Separation upon Electron Transfer Element
    LI XiangYuan, YI HaiBo, LIU JiFeng, TONG Jing, HE FuCheng
    2001, 22(12):  2056-2060. 
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    The geometries of neutral indole and phenol, as well as their cation radicals and anion radicals, have been optimized by using AM1 method. In the doublewell potential constructions of the electron transfer (ET) between indole cation radical and neutral phenol, linear reaction coordinate approximation has been adopted, and the conductorlike screening model has been involked. Based on the indolephenol doublewell potential, the reaction heat and the inner reorganization energy of ETbetween tryptophan and tyrosine have been evaluated. AM1 method has been applied to obtain the geometries and the conformations of TrpH(Pro)nTyrOH(n=0-3) model systems. ETmatrix elements for the intramolecular ETin those model peptides have been estimated through the determination of the minimum of the energy splitting factor.
    Theoretical Studies on Vibrational Spectra of Urea
    GUO Yong, XIE DaiQian, XUE Ying, YAN GuoSen
    2001, 22(12):  2061-2064. 
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    The optimized geometries, vibrational force fields and infrared intensities of the urea molecule were calculated by density functional theory method(DFT) with 6311++G(2df,2pd) basis set. The theoretical force field was scaled by using the scaled quantum mechanical force field method with only two scale factors. The root mean square error was found to be 14 cm-1 for urea. The assignment of the fundamentals for CO(NH2)2 and its deuterated isotopomer CO(ND2)2 were also performed according to the potential energy distributions.
    Surface Modification of Ultra-fine Barium Titanate
    CUI AiLi, CHEN RenZheng, WEI JingZhi, LI LongTu
    2001, 22(12):  2065-2067. 
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    By using solgel method, SiO2 nanofilms of 5 nm were coated on the surface of ultrafine BaTiO3. The coated powders and ceramics were analyzed by using HRTEM, XPSand XRDrespectively. The coating mechanism was first reported that water glass solgelated on TiO2-x surfaces after BaTiO3 was hydrolyzed slightly. Compared with pure BaTiO3, SiO2 coating process can enhance the sintering property at the lower sintering temperatures from 1260 ℃ to 1190 ℃. The ceramic shrinkage mass fraction changes from-15 to-19.3. And the coating process improves the dielectric property of ceramics, flatten εT curve. The coating process is promising for the thin layer BaTiO3based capacitors.
    Synthesis of Guaiacol by Catechol and Methanol on Oxide Catalyst
    LI XueMei, ZHANG WenXiang, PAN ChunLiu, WANG GuiYing, JIANG DaZhen, WU TongHao, TANG AuChin
    2001, 22(12):  2068-2071. 
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    Complex oxide catalysts of Al1P1.30TiaSib(a=0-0.51, b=0-0.90) were prepared by ununiform precipitation method. The vapor phase omethylation of catechol with methanol over the synthesised oxides was studied. The activity and selectivity of these catalysts were greatly dependent on the compositions, the phase structure and surface properties of the catalysts. Among the samples tested, Al1P1.30Ti0.30Si0.17 gave the highest yield 86 for guaiacol and 92 conversion of catechol at 553 K.
    Effect of SO2 on NO Catalytic Oxidation(Ⅱ) Interaction Betweenγ-Al2O3 Support and SO2
    LI Ping, ZHAO Yue, LU GuanZhong, ZHAO XiuGe, LU WenZhi, XIAO WenDe
    2001, 22(12):  2072-2076. 
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    The effect of SO2 on the catalytic oxidation of NOover γAl2O3 support was studied at temperature of 423 K. It was found that the activity of γAl2O3 for the oxidation of NOto NO2 was enhanced temporarily in the presence of SO2. The adsorption capacity of NOand SO2 was also promoted by each other. The interaction between γAl2O3 and SO2 was discussed by using of various material characterization techniques such as TPD, FTIR, XRD, BET, solid acid detection and so on. After long time reaction in the presence of SO2, no solid nitrate and sulfate were detected in γAl2O3, but the Lacid and Bacid concentrations were increased. TPDspectra show that the desorption peak of NO2 species in the range of higher temperatures mounts up after SO2 coadsorption with NOand O2 on γAl2O3. FTIRresults indicate that different kinds of adsorption species are present on the surface of γAl2O3 and the main NOadsorption species are changed by SO2 coadsorption. An active surface species, which may be responsible for the higher oxidation activity of γAl2O3 in the presence of SO2, is supposed to be formed on the surface of γAl2O3 via SO2, NO, O2 and surfaceadsorbed hydroxide. The activity of γAl2O3 decreases while the surface of γAl2O3 is covered gradually by a strong adsorption of SO2.
    DFT Study on the Reaction Mechanism of O(3P)+O2H——OH+O2
    PAN XiuMei, WANG RongShun, SU ZhongMin, James Tyrrell
    2001, 22(12):  2077-2080. 
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    The reaction mechanism of O(3P)+O2HOH+O2 has been studied by using Density Function Theory. The geometries of reactions, transition states, intermediates and products have been optimized by PW91/631+G* basis set and verified by frequency analysis. The reaction pathway and isomerized process were traced by Fukui's theory of intrinsic reaction coordinate(IRC). The reaction channels were verified. The results show that the reaction is a multistep and multichannel complex one followed by heat giving out strongly. Along the reaction path there are a little of transition state and two intermediates. The potential energy of IM1→TS1 is larger than that of IM2→TS2. The reaction heat is 372.822 kJ5mol-1. IM1TS3IM2 can isomerize each other.
    Theoretical Simulation of the Interaction Between Cu and the Surface of Polyimides
    ZHANG XiuBin, LI ZeSheng, Lü ZhongYuan, YU KunQian, SUN ChiaChung
    2001, 22(12):  2081-2084. 
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    Molecular mechanics simulation is used to study the static behavior of a metal Cu monolayer on the trilayer model of pyrometallic dianhydrideoxydianiline(PMDAODA). It is shown that the monolayer forms aggregates on the surface of PMDAODA. The reason is that the cohesive interaction between Cu atoms is stronger than the adhesive interaction between the Cu monolayer and the surface of PMDAODA. In the cohesion, the van der Waals interaction plays an important role, whereas in the adhesion, the electrostatic interaction is a dominant factor. Furthermore, by means of molecular dynamics simulation, the temperature influence on the interaction of Cu/PMDAODAinterface is studied.
    Studies on Coupling of Dehydrogenation of Ethane with Reversed Water-gas Shift Reaction for Ethylene
    GE Xin, SHEN JianYi
    2001, 22(12):  2085-2090. 
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    Areview is presented on coupling of dehydrogenation of ethane with reversed watergas shift reaction for ethylene synthesis. The SiO2 and Silicalite2 supported chromium, manganese and iron oxide catalysts were found to exhibit a high performance in the dehydrogenation of ethane in the presence of CO2. CO2 can be activated by the surface basicity. The results show that the synergetic action of acidity and basicity is important to the increase of the catalytic activity. The function of CO2 is to abstract H2 and to resistant coke formation during the dehydrogenation of ethane. The reaction mechanism and effects of reaction condition on the dehydrogenation of ethane were also evaluated.
    Investigation of Surface Structures of Supported ZnO/SiO2 and ZnO-SiO2 Sol-gel Catalysts
    LIU QingSheng, WANG ZhenLü, YU JianFeng, YANG PiaoPing, WANG GuoJia, YANG HongMao, ZHENG DaFang, WU TongHao
    2001, 22(12):  2091-2093. 
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    ZnO/SiO2 and ZnOSiO2 catalysts were prepared by the impregnation and solgel method, respectively. The characterization of the catalysts by XPSand FTIRindicated that much "free" zinc oxide and unreacted Si—OHexisted on the surface of ZnO/SiO2 sample. As for ZnOSiO2 solgel catalyst, the corresponding phenomena were not observed. The prepared samples were also used as the catalysts for decomposition of 2butanol. Ahigh selectivity for dehydrogenation was observed over the supported catalyst. However, a high selectivity for dehydration was shown over the ZnOSiO2 solgel catalyst. The opposite selectivity for dehydration or dehydrogenation observed over the two kinds of catalysts may be just because of the different surface structures of the catalysts.
    Theoretical Studies of the Chemisorption of CO on Supported-metal Catalysts of Ru, Rh, Pd(Ⅱ)
    LIU YongDong, SUN RenAn, WANG ChangSheng
    2001, 22(12):  2094-2096. 
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    By using OCMOSiH3(M=Ru, Rh, Pd) as models to imitate the chemisorption of COon the silicasupported catalysts, the geometries and frequencies have been performed for the complexes by Gaussian programs, at the B3LYP/LANL1DZlevel. An influence of the C—Obond has been studied and the support effects of silica are obtained. The support effects of silica make the COfrequency an upward shift, which means that the weakened degree of C—Odecreases and the bond strength of C—Oincreases naturally compared to those of the nonsilicasupported catalysts. So the products on the silicasupported catalysts shift to the oxygenates.
    Measurement of Conductivity for Mixed Eletrolytes
    WANG Ting, LI HaoRan, HAN ShiJun 
    2001, 22(12):  2097-2099. 
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    The conductivity of dilute aqueous solutions of CaCl2, CaCl2NaCl, CaCl2KCl have been determined at 298.15 K. The limiting molar conductances, association constants and ion size are evaluated by means of the FuossOnsager equation. The ion association of CaCl2 has been discussed, and the mixtures have been correlated as pseudo binary electrolytes.
    Separation of Neutral Amino Acids on Columns Packed with Polystyrene-Based Strongly Acidic Cation Exchange Resins with Low Ion Exchange Capacity
    LIU JuXiang, LIU GuoDong, YAN HuSheng, CHENG XiaoHui, HE BingLin, JIANG GenHua, YANG GuoYing
    2001, 22(12):  2100-2103. 
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    Aseries of polystyrenebased strongly acidic cation exchange resins with different ion exchange capacities were synthesized via the reversedsulfonation of a commercial polystyrenebased strongly acidic cation exchange resin(001×7) or sulfonation of styrenedivinylbenzene copolymer. The chromatographic separation of alanine and valine or valine and leucine on columns packed with these resins was carried out. The results showed that the chromatographic properties of the two kinds of the abovementioned resins on the separation of alanine and valine were almost the same. The retention volume of alanine was less than that of valine on the same column with various ion exchange capacities, and the retention volume of valine was less than that of leucine on the column with the ion exchange capacity of 1.67 mmol/mL. The retention volume of alanine decreased when the ion exchange capacities decreased from 2.02 to 1.00 mmol/mL. The retention volume of valine slightly decreased when the ion exchange capacities decreased from 2.02 to 1.67 mmol/mLand remained almost unchanged when the ion exchange capacities decreased from 1.67 to 1.00 mmol/mL. These results indicated that the interaction between neutral amino acids and the polystyrenebased strongly acidic cation exchange resin includes ionic and hydrophobic interactions. And there may be synergy between the two interactions. The better separation efficiency of neutral amino acid may be obtained by using the resin with a lower ion exchange capacity.
    The Effect of the Interface Between the Third Phase and the Polymer Blend on the Formation of the Gradient Morphology in Polymer Blend
    KONG XiangMing, WANG Zhen, XIE XuMing
    2001, 22(12):  2104-2107. 
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    In this paper, the induction effect of the interface between the third phase(such as the substrates, the foreign substances) and polymer blend system on the formation of the gradient morphology in polymer blend was studied. It was found that all the third phases(such as the substrates, the inserted films, the set foreign particles in this case) could lead to the formation of the gradient morphology in PP/EVAc blends by annealing. In other words, the particle size and the content of the EVAc dispersed phase gradually increased from the bulk to the interface between the third phase and the polymer blend system. When the two PIfilms were inserted into the blend system, the effect of the distance between the two inserted PIfilms on the morphology of LDPE/EVAc blend was also investigated. It was found that the interfaceinduced gradient structures began to overlap when the distance of the two inserted films was less than two times of the expectant formed thickness of the gradient morphology for the case of the individual PIfilm inserted. If the distance of the two films was smaller, all the droplets of the dispersed phase fastly grew simultaneously instead of forming the gradient morphology. It should be caused by the mutual interference of the induction effect of the interface between the two PIfilms and the blend system. This corresponds to the case of the dispersed droplet coarsening process under 2-dimentional conditions in polymer blend systems. All the results above supported the conclusion we presented in our previous paper, i.e., the existence of interface between the third phase and the polymer blend greatly accelerated the coarsening process of the droplets in the polymer blend.
    Interaction Between Octyl Acrylate Copolymers Bearing Functional Groups in Solutions(Ⅰ)
    WANG YuHua, QI GuoRong, LI HuiLing, PENG HongYun, YANG ShiLin
    2001, 22(12):  2108-2112. 
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    An interpolymer complexation formed by polymer chains bearing complementary proton donor and acceptor was studied. In this study, poly(styrenecooctyl acrylatecoacrylic acid) as proton donating polymer(PDP) and poly(styrenecooctyl acrylateco4vinylpyridine) as proton accepting polymer(PAP) with various macromolecular chain compositions were prepared by emulsion copolymerization. Complexed solutions formed by PDPand PAPwere prepared, and reduced viscosity enhancement of the complexed solutions were studied with viscometry. The effects of the polymer solution concentration, copolymer compositions and solvent nature on the interpolymer interactions were investigated through a comparison of the reduced viscosity enhancement factor R of different complexed solutions. The results showed that the reduced viscosities of PDP/PAPcomplexed solutions were higher than weighted average of their constituents and R increased with increasing complexed polymer solution concentration generally. With the change in mole fraction of AA(xAA) in blends, there existed a Rmax indicating the strongest interaction between PDPand PAP. In toluene as an inertia solvent not impacting on acidbase interaction, due to steric shield effect of side chains in octyl acrylate unit and self association of carboxyl in PDPaltogether, mole fraction of AAcorresponding to Rmax, xAA,max, increased gradually up to 0.5 as OAcontent decreased in PDPand relatively insensitive to composition of PAP. Whereas in THFas solvent, xAA,max was generally independent of composition of PDPand approximated to 0.5 due to THFbeing capable of destroying interpolymer interaction as well as selfassociation of carboxyl. In addition, the strength of interpolymer interaction between PDPand PAPwas increased with increasing OAcontent in component copolymers.
    Preparation of Chitosan/SiO2 Hybrid Polymer Material via sol-gel Process
    ZHU AiPing, YAN Xin, ZHANG Can, SHEN Jian, LIN SiCong
    2001, 22(12):  2113-2116. 
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    By use of chitosan, butyryric anhydride, methacryloxypropyl trimethyloxysilane(MPTMS), tetraethyloxysilane(TEOS), firstly butyrylchitosanMPTMSwas synthesized by Michael addition reaction, and then went on acid catalysizing solgel process, lastly transparent butyrylchitosan/SiO2 hybrid polymer materials were prepared. FTIRwas used to characterize the structure. The results of SEM, TGAand Test of Mechanical Properties indicate that the preparation techniques have great effect on surface topography, thermal degradation temperature and mechanical properties of hybrid polymer materials.
    Preparation of Poly(styrene-co-4-vinylpyridine)/Silica Nanoscale Hybrids Supported Cyclopentadienyltitanium Trichloride(CpTiCl3) Catalyst and Styrene Polymerization
    ZHU Ning, TANG Tao, CUI DongMei, FENG ZhiLiu, HUANG BaoTong
    2001, 22(12):  2117-2119. 
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    To obtain a novel support with practical value for metallocene catalyst(ηC5H5)TiCl3(CpTiCl3), poly(styrene-co-4-vinyl-pyridine)/SiO2 nanoscale hybrid material(SrP/SiO2) was firstly produced as support. After pretreatment by methylaluminoxane(MAO), the hybrid materials reacted with CpTiCl3. The results from SAXS, SEMand TEMindicated the morphology and structure of organic/inorganic hybrid materials, and the size of inorganic particle in hybrid was nanoscale. The results from IRand XPS-showed that there were two possible cationic active species in the hybridsupported catalyst, the polymerization results of styrene proved this possibility.
    Micelles Behavior of P(Styrene-b-acrylic acid) Block Copolymer at Different pH and Calcium Ion Concentration
    DU ManQuan, SHI LinQi, AN YingLi, HE BingLin
    2001, 22(12):  2120-2122. 
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    The micelles behavior of amphiphilic block copolymer P(Styrenebacrylic acid), in aqueous solvent was studied by dynamic light scattering and TEMtechniques. The diameters of micelle decreased and then increased with the decrease of the pHof the solution, and the similar phenomenon was also detected with the increase of the concentration of the calcium ion. Without added acid, the micelles were small spheres of low polydispersity with an average diameter 48 nm. When the value of pHwas less than2, the micelles were unstable. It was found that the Ca2+ was linked with the carboxyl in the same micelle when the concentration of the CaCl2 was less than0.2 mg/mL. The diameter of micelle was smaller than the one without Ca2+. The Ca2+ was linked with the carboxyl between the different micelles when the concentration of the CaCl2 was more than0.5 mg/mLand the micelle was unstable. The diameters of micelles(from 37 nm to 100 nm) can be controlled by adding an appropriate concentration of CaCl2 between0.20.5 mg/mL.
    Thermal Analysis of Liquid Crystal Phase Transition Using FTIR Spectroscopy
    WU Qiang, LI ChenXi, LI XueChen, LI YanHong
    2001, 22(12):  2123-2125. 
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    Thermal spectra of liquid crystal, pndodecyloxy benzoic acid were collected at 26-150 ℃ by FTIRmicrospectroscopy. Conformational apparent enthalpy differences ΔH in phase transitions have been determined by van't Hoff equation at constant pressure and plotted with temperature. Compared to DSC, these enthalpies plot with temperature could be divided into three types. The first one was long alkyl chain group which has only one apparent endothermic enthalpy peak at 95 ℃. The second one was partial carbonyl and aromatic ether groups has three endothermic enthalpy peaks in the phase transition. The third type including benzoyl group which has one exothermic enthalpy peak at 95 ℃ and a broad endothermic enthalpy peak in the range of 128-140 ℃. These differences indicated that oxybenzoic acid part of dodecyloxy benzoic acid recrystallized to cycle dimer during alkyl chain melting in crystalsmectic phase transition.
    Preparation and Surface Properties of Perfluoroalkylethyl Acrylate Copolymer
    ZHOU YuMing, XU QunHua, HUANG JingYan
    2001, 22(12):  2126-2127. 
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    The Perfluoroalkylethyl acrylate copolymer, with an excellent property of waterproof and oilproof, was prepared by emulsion polymerization. The surface characterization of the copolymer was performed by surface free energy calculation and AESanalysis. The calculated result of surface free energy was 0.0126 J/m2, which is much lower than that of organosilicon polymer. It was found by AESthat perfluoroalkyl groups for the outermost layer has a decisive effect on the surface free energy.
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