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Table of Content

    24 September 2002, Volume 23 Issue 9
    Articles
    Synthesis and Crystal Structure of a Tetranuclear Cluster [(η5-C5Me5)WS3Cu3Br2(PPyPh2)2]
    XU Qing-Feng, CHEN Jin-Xiang, LIU Quan, JI Shun-Jun, LANG Jian-Ping, SHEN Qi
    2002, 23(9):  1641-1644. 
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    Reaction of [PPH4]2[(η5-C5Me5)WS3(CuBr)3]2 in CH3CN with PPyPh2 in a molar ratio of 1∶4 gave rise to red crystals of [(η5-C5Me5)WS3Cu3Br2(PPyPh2)2]. It was characterized by elemental analysis, IR, UV-Vis and 1H NMR spectroscopy and X-ray diffraction. It crystallizes in a triclinic system with space group P1 and unit cell parameters a=1.5459(7) nm, b=1.620(1) nm, c=1.0180(2) nm, α=94.18(3)°, β=97.38(3)°, γ=111.8(4)°, Z=2, R=0.031. The structure consists of a distorted WS3Cu3Br cubane where the Cu(3)—Br(1) bond is broken. Cu(1) and Cu(2) atoms adopt a distorted tetrahedral geometry coordination while Cu(3) assumes an approximately trigonal planar geometry. W—Cu(1), W—Cu(2) and W—Cu(3) distances are 0.27041(9), 0.27327(8), and 0.26785(9) nm, respectively.
    Preparation and Self-assembly of Plate-like Nanocrystal of PbSO4 via Microemulsions Approach
    ZHOU Hai-Cheng, XU Jian, LI Ya-Dong
    2002, 23(9):  1645-1647. 
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    Plate-like nanocrystal PbSO4 was synthesized in quaternary W/O microemulsion system containing water, Triton X-100, cyclohexane and n-pentanol. Transmission electron microscopy(TEM) was utilized to characterize the morphology of PbSO4 as-prepared and electron diffraction(ED) analysis identified the crystal nature of the product. Two key variables-X0(molar ratio of water to surfactant) and reactant concentration in water were investigated to reveal the formation and self-assembly mechanism as well as the shape and size changing of plate-like nanocrystal PbSO4 under different conditions.
    Influence of Methanol Addition on Diamond Films Deposition with Hot Cathode DC-PCVD Method
    JIANG Zhi-Gang, JIN Zeng-Sun, BAI YI-Zhen, CAO Pei-Jiang, ZHANG Lu, YANG Guang-Liang, LI Jun-Jie, LÜ Xian-Yi
    2002, 23(9):  1648-1650. 
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    Diamond films were deposited with hot cathode DC-PCVDmethod in this paper. The methanol addition influences on discharge state and diamond film growth characteristics were studied. The research results show that a proper amount of methanol addition is beneficial to the stability of glow discharge. It can keep the cathode surface clean and improve the film quality. The growth characteristics of diamond films are analyzed by means of SEMand Raman spectroscopy.
    Molecular Dynamics Study of the Templating Abilities of Organic Amines in 2D Layered Aluminophosphates with Al3P4O163- Stoichiometry
    LI Yi, MIAO Peng, LI Ji-Yang, YU Ji-Hong, YAN Wen-Fu, XU Ru-Ren
    2002, 23(9):  1651-1655. 
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    The templating abilities of various organic amines in the formation of 2Dlayered aluminophosphates with Al3P4O163- stoichiometry were investigated by the combination of molecular dynamics simulation and the rapid Monte Carlo approaches. In terms of the host-guest non-bonding interaction energies(including VDWenergy, H-bond energy and Coulomb energy), some experimental phenomena can be well explained, and some suitable templates for a given inorganic layers can also be predicted. By choosing the theoretically predicted organic amine as template, a new 2Dlayered aluminophosphate, Al3P4O16·1.5H3NC6H10NH3, was synthesized successfully under solvothermal conditions. This work will further assist the rational synthesis of layered and microporous materials.
    Synthesis and Crystal Structure of the Phenylsilyl Derivative of α-A-PW9O349- (TBA)3[α-A-PW9O34(PhSiO)3(PhSi)]·2H2O
    WANG Jing-Ping, LI Ming-Xue, NIU Jing-Yang 
    2002, 23(9):  1656-1659. 
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    Reaction of the trivacant heteropolyanions β-A-PW9O349- with PhSiCl3 leads to the formation of the organosilyl derivative (TBA)3[α-A-PW9O34(PhSiO)3(PhSi)]·2H2O. The complex has been characterized by elemental analysis, IR and UV spectroscopy, X-ray crystallography, TG-DTA methods. Crystals of (TBA)3[α-A-PW9O34(PhSiO)3(PhSi)] are trigonal, space group R3, with unit cell parameters: a=1.41696(16) nm, b=1.42163(16) nm, c=1.41661(16) nm, α=99.801(17)°, β=99.843(17)°, γ=99.844(17)°, V=2.7111(5) nm3. Z=1, R=0.0548. The anion consists of one α-A-PW9O349- framework which are grafted by three PhSiOgroups through six Si—O—W bridges, each of which is attached to the fourth PhSiO through three Si—O—Si bridges and become saturated closed cage structure.
    Synthesis, Crystal Structure and Anti-prostate Cancer Activity of a Novel Organic-inorganic Hybrid Material:(C3H5N2)4PMoMo11O40·4DMF·2H2O
    HAN Zheng-Bo, CHANG Ya-Ping, LUAN Guo-You, LI Juan, WANG En-Bo
    2002, 23(9):  1660-1663. 
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    Anew compound, (C3H5N2)4PMoMo11O40)·4C3H7NO·2H2O, was synthesized and structurally characterized by elemental analysis, ESRspectra and X-ray diffraction. This is the first example of imidazole-polyoxometalate species to our knowledge. It crystallized in a triclinic space group, P1 with a=1.2423(3) nm, b=1.2666(3) nm, c=1.3341(3) nm, V=1.7423(6) nm3, α=70.56(3)°, β=71.16(3)°, γ=64.18(3)°, Z=1, R=0.0585, wR=0.1885. X-ray crystallographic study showed that the crystal structure was constructed by electrostatic attractions and hydrogen bonds between a dodecamolybdophosphoric anion and an imidazole. Anti-prostate cancer(PC-3m) activities of the title compound are also reported.
    The Construction, Expression and Properties of Monkey MetallothioneinⅠ Mutants(N4C, T27C, N4C/T27C)
    HUANG Zhong-Xian, GAO Yuan, YU Wen-Hao, ZHANG Su-Yan, YANG Peng-Yuan
    2002, 23(9):  1664-1666. 
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    To evaluate the role of Cys-X-Cys fragment in the formation of domains containing metal-thiolate cluster in metallothionein, we used site-directed mutagenesis to replace Asn-4 and Thr-27 in β-domain of monkey metallothionein Ⅰ with Cys. Thus, at the amino acids sequence level, the β-domain was designed to mimic the α-domain. Then we studied the recombinant monkey wild type metallothionein Ⅰ(WTmkMT), and mutants of mkMT N4C, mkMT T27C and mkMT N4C/T27C, using UVspectroscopy, CDspectroscopy, electrospray ionization mass spectroscopy, pHtitration and the reaction with DTNB [5,5′-dithiobis(2-nitrobenzoic acid)]. We found that in the mutants also existed a metal ion (Ⅱ)-thiolate cluster wrapped up by the peptides. In addition to the origin α-domain, a new domain containing 4-metal ion(Ⅱ)-thiolate cluster was formed in mkMT N4Cand mkMT N4C/T27C. And this new domain was more stable than the natural β-domain. The obtaining of mkMT N4C, mkMT T27Cand mkMT N4C/T27C laid down a base for the further study of the role of Cys-X-Cys fragment in the formation of metallothionein′s structure.
    Synthesis, Photoluminescence and Electroluminescence of8-Hydroxyquinolato-p-methylphenolato-zinc
    HE Yi, WANG Guang, CHEN Jie-Sheng
    2002, 23(9):  1667-1669. 
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    Atri-coordinated 8-hydroxyquinolato-p-methylphenolato-zinc complex was first synthesized, and its photoluminescent spectra(PL) and UVabsorption spectra were investigated. Double layer organic lighting diodes(OLEDs), ITO/PVK∶ZnqP(80 nm)/Mg∶Ag was fabricated by using this complex as the luminescent layer. Green electroluminescence(EL) was observed, and this complex was found as a good electroluminescence emitting material.
    Hydrothermal Synthesis and Characterization of a New Compound [Ni(en)3]2[Ni(en)2(H2O)2]·[As6V15O42]·4H2O
    LUAN Guo-You, WANG Ming-Hui, HAN Zheng-Bo, WANG En-Bo, LU Ying, LI Yang-Guang, HU Chang-Wen, HU Ning-Hai, JIA Heng-Qing
    2002, 23(9):  1670-1672. 
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    Anew compound, [Ni(en)3]2[Ni(en)2(H2O)2][As6V15O42]·4H2O, was first prepared by hydrothermal synthesis and characterized by elemental analysis, IR, TGA-DSC, ESRand single crystal X-ray diffraction. Crystal data: monoclinic, space group Cc, a=1.5236(3) nm, b=2.0518(4) nm, c=2.3959(5) nm, β=97.41(3)°, V=7.427(3) nm3, Z=4, R=0.0570, wR2=0.1357. The polyanion consists of six AsO3 pyramids and fifteen VO5 pyramids. Counterions are complexions with octahedral structure, which consist of NH2CH2CH2NH2 and Ni+2+.
    Syntheses and Characterization of Novel Open-framework Zinc Germanate Phosphates
    LI Dong-Sheng, ZHU Guang-Shan, LI Ya-Feng, GAO Fei-Fei, LI Bin-Song, QIU Shi-Lun 
    2002, 23(9):  1673-1675. 
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    Three open-framework zinc germanophosphates have been synthesized from ethylene glycol systems of Zn(Ac)2·2H2O-H3PO4-R-GeO2-Py-EG, where R stands for an amine and EGfor ethylene glycol. It was found that by selecting proper amines as structure-directing templates during crystallization open-framework zinc germanophosphates were synthesized. The structures of the zinc germanophosphates were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM), inductively coupled plasma(ICP) analysis, infrared spectroscopy(IR).
    SERS Studies on the Interaction of Berberine With ct DNA
    WANG Shu-Ling, YU Jun-Sheng
    2002, 23(9):  1676-1679. 
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    The interaction between berberine and ct DNAwas investigated by using FT-Surface Enhancement Raman Scattering(SERS) spectroscopy. The FT-SERSspectra of berberine and its complex with DNAwere recorded in the Ag sol and pH7.20 Tris solution. Vibrational assignment of the SERSactive modes was done on the basis of normal coordinate analysis. Some Raman bands of berberine are dramatically increased in intensity on the silver colloid. Results suggest that berberine ring system around the nitrogen positively charged center should assume the perpendicular or at least tilted stances with respect to the surface of Ag sol nanoparticle through the electrostatic interaction. When ct DNAis added into the berberine solution, much stronger SERSsignal with a factor of 1.5 was obtained for the most of FT-SERSbands of the molecule due to DNAbinding; only a few bands approach to disappear in intensity. This result implies that there are two binding modes between berberine and double helix DNA. The shifts of some Raman band were also observed on the DNAbinding. SERSexperiments show that the isoquinolone moiety of berberine molecule may be accommodated in the minor groove of DNAhelix. Grooving binding is very likely to be the dominant mode in the interaction of berberine with double helix DNA.
    A Biosensor for Nucleic Acid Hybridization Using 2,3,5-Triphenyl-tetrazoliam Chloride as Electrochemical Intercalator
    CHENG Qiong, PENG Tu-Zhi
    2002, 23(9):  1680-1683. 
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    Asensitive electrochemical biosensor is reported for the detection of nucleic acid hybridization and sequence-specific DNAs. The biosensor is based on a graphite electrode modified ssDNAusing 2,3,5-triphenyl-tetrazolium chloride(TTC) as hybridization indicator. TTCshows high electroactivity and low background current in electrochemical measurements. It binds to dsDNAs on the electrode surface with high selectivity. The reductive current of intercalated TTCis proportional to the concentration of target ssDNAin the range of 6.0×10-6—2.0×10-8 mol/Lin cyclic voltammetry. The detection limit of the biosensor for DNAis 6.0×10-11 mol/Lin differential pulse voltammetry.
    Synthesis, Characterization and Evaluation of a Novel Ester-bonded for Reversed-phase HPLC
    HUANG Xiao-Jia, LIU Xue-Liang, WANG Jun-De, CONG Run-Zi
    2002, 23(9):  1684-1687. 
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    Anovel ester bonded packing for reversed phase HPLC(RP HPLC) was synthesized by reacting octanoic acid with β (3,4 epoxycyclohexyl) ethyltrimethoxy silane and then the intermediate product was coupled onto porous silica. Characterization of the prepared packing was carried out with elemental analysis, solid state 13 C NMR, and Fourier transform infrared spectrometry. Hydrophobicity, selectivity and silanophilic activity of the packing were evaluated by using organic components including acidic, basic and neutral analytes as probe molecules and methanol water as binary mobile phase. The usage ranges of pHand stability of the packing were also evaluated. The results show that the novel stationary phase has excellent chromatographic properties and resist to hydrolysis between pH=2.5-7.5, it can be used for the separation of basic solutes efficiently.
    Isotope Dilution Inductively Coupled Plasma Mass Spectrometery for the Determination of Lead in Plants and Human Hair
    YANG Chao-Yong, HUANG Zhi-Yong, ZHAO Li, ZHUANG Zhi-Xia, WANG Xiao-Ru
    2002, 23(9):  1688-1691. 
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    Amethod of isotope dilution inductively coupled plasma mass spectrometry for the determination of lead in plant and human hair samples is established. The effects of instrumental parameters on the isotope ratio measurement were studied and discussed. For the precise determination, the data acquisition parameters were optimized. Tl was used as internal standard for the correction of mass bias and system driftment. The propagation of uncertainty in ID-ICP-MS was discussed to optimize the amount of concentrated isotope spiked. The analytical results of lead in some certificate reference materials agree well with the certificated valuesl.
    Determination of Bioavailable Cadmium in Environmental Samples by IP-RP-HPLC Coupled with On-line Fluorescence Assay
    LI Bin, WANG Qiu-Quan, YAN Hua, YANG Li-Min, HUANG Ben-Li
    2002, 23(9):  1692-1694. 
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    Anovel reserved-phase ion-pair liquid chromatographic method using hexadecyltrimethylammonium bromide(HTMAB) as an ion-pair reagent for separating the complexes of metal and 8-hydroxyquinoline-5-sulphonic acid(HQS) coupled with on-line fluorescence detection has been developed. The chromatographic behavior of metal-HQScomplexes in the proposed system was systematically investigated.When the C18 column modified by HTMABand the suitable mobile phase coupled with fluorescence detection(λex=388 nm; λem=518 nm) were employed, the detection limit of cadmium is 7.72 ng/mLwith an injection volume of 20 μL, and the linear range of calibration curve for cadmium is 50—800 ng/mL. It was successfully applied to determination of bio-available cadmium in polluted soils of China. Moreover, the possible species of Cd-HQSon the column has been investigated by log-log plot analysis.
    Ant Colony Algorithm in Chemistry and Its Application in First Derivative Fluorescent Spectra Analyzing
    DING Ya-Ping, SU Qing-De, WU Qing-Sheng
    2002, 23(9):  1695-1697. 
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    Anew method of chemometrics━━Ant Colony Algorithm in Chemistry has been developed. In this paper, the evaluation function, the parameter choice and the basic principle have been discussed. The proposed method has been applied to the analysis for first-derivative fluorescent mixed spectra of tryptophan, tyrosine and phenylalanine, and the relative errors are within ±5%. The new method has obvious superiority on the sides of the convergence speed and calculation precision as compared with Partial Last Squares(PLS) and Genetic Algorithms(GA).
    Application of High-speed Countercurrent Chromatography-Electrospray Ionization-Mass Spectrometry in Analysis of Traditional Chinese Herbs
    WU Fang-Yong, DAI De-Shun, WANG Yi-Ming, LUO Guo-An
    2002, 23(9):  1698-1700. 
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    In this paper, it comes true that the system of HSCCCcoupled with ESI MS/MSis utilized to on line separate, purify and detect tanshinoneⅡA from the ethyl ester crude extract of Salvia miltiorrhiza Bunge, which is at purity of 98% in HPLCanalysis.
    Studies on Fluorescent Labeling of Marine Sulfated Polysaccharide 911
    LI Fu-Chuan, GENG Mei-Yu, LI Ying-Xia, LI Jing, MIAO Ben-Chun, Guan Hua-Shi
    2002, 23(9):  1704-1708. 
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    The reducing terminal of marine sulfated polysaccharide(911) was used to selectively insert primary and secondary amines by reductive amination. 911 was bounded to 4-(2-aminoethylphenol), followed by labeling the 911-Tyr with fluorescein-5-isothiocyanate(FITC) at the secondary amino group. High-performance size-exclusion chromatography(HPSEC), ultraviolet/visible(UV-Vis) spectroscopy and nuclear magnetic resonance spectroscopy(NMR) demonstrated the binding of tyramine to 911 and the labeling of FITCto 911-Tyr respectively. Furthermore, +1H NMRspectra and UV-Vis spectra revealed about 60% binding of tyramine to 911 and about 80% labeling of FITCto 911-Tyr. The anticoagulant activity of labeled fluorescent compound exhibited 13.40 U/mg equivalent to that of unlabled 911. In addition, the labeled compound was demonstrated to fluorescently stain lymphocytes without any cytotoxity. Taken together, the selectively "end point attached" method might be widely used for fluorecent labeling to those polysaccharides with reducing terminal.
    Dual Flrorescence of Anilino Substituted Benzanilides in Non-polar Solvent Cyclohexane——Direct Spectroscopic Evidence for the Excited-state Charge Transfer
    ZHANG Xuan, MA Li-Hua, SUN Xiang-Ying, WANG Chao-Jie, LI Zhao, WU Fang-Ying, JIANG Yun-Bao
    2002, 23(9):  1707-1703. 
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    The fluorescence spectra in cyclohexane of a series of benzanilides(BAs) with different para substituents at the anilino moiety revealed that BAs emitted dual fluorescence, with one normal weak emission at ca . 330 nm and an abnormally long wavelength emission ranging from 460 to 550 nm. The long wavelength emission was found strongly dependent of the electron donating capacity of the substituent at the anilino moiety and a stronger electron donating substituent led to a red shift in the emission. The energies of the long wavelength emission of the BAs were correlated to the oxidation potentials of the donors, ED/D+, and a nice linear correlation was found with a slope of +066, which clearly pointed to the charge transfer character of the emissive state for the long wavelength emission and the high decoupling extent of the charges in the CTstate. This is the first report that shows the direct evidence for the CTnature. The results might be of significance in understanding the photophysics of peptide and protein and in designing novel fluorescent chemosensors.
    Synthesis and Bioactivity of 5-Avermectin B1a Esters
    LIAO Lian-An, LI Zheng-Ming, FANG Hong-Yun, ZHAO Wei-Guang, CHEN Ming-De, FAN Zhi-Jin, LIU Gui-Long
    2002, 23(9):  1709-1714. 
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    Ten 5-Avermectin B1a ester derivatives were prepared from avermectin B1a and carboxylic acids in the systems of DCC/DMAP. Their chemical structures were confirmed by IR, 1H NMR, 13C NMR and MS. Their insecticidal activity was evaluated against Aphis gossypii Glover and Tetranychus truncatus Ehara. It was found that some compounds showed a higher insecticidal activity than Avermectin.
    Synthesis and Reactivity of Group 6 Metal Carbonyl Complexes Containing Bis(3,5-dimethyl-4-benzylpyrazol-1-yl)methane
    WANG Zhi-Hong, TANG Liang-Fu, YANG Zhi, WANG Ji-Tao
    2002, 23(9):  1715-1718. 
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    Bis(3,5-dimethyl-4-benzylpyrazo-1-yl)methane, CH2(3,5-Me2-4-BzPz)2, is synthesized by the reaction of 3,5-dimethyl-4-benzylpyrazole with CH2Br2 under phase transfer catalysis, which reacts with M(CO)6(M=Cr, Mo or W) under UV irradiation at room temperature to yield bis(3,5-dimethyl-4-benzylpyrazo-1-yl)methane tetracarbonyl chromium, molybdenum or tungsten complex, respectively. Treatment of bis(3,5-dimethyl-4-benzylpyrazo-1-yl)methane tetracarbonyl molybdenum or tungsten with SnCl4 gives the Mo(W)—Sn heterobimetallic complexes in good yields. The molecular structure of CH2(3,5-Me2-4-BzPz)2W(Cl)(CO)3(SnCl3) determined by X-ray crystallography shows that the six-membered W—N—N—C—N—N metallacycle is in a boat form, and no chlorine bridge is observed. The compound crystallizes in the triclinic space group P1, with a=1.0929(9) nm, b=1.282(1) nm, c=1.282(1) nm, α=102.35(1)°, β=108.62(1)°, γ=97.00(1)°, V=1.799(3) nm3, Z=2, R=0.058, wR=0.1015.
    Syntheses of Polyarylamino-benzaldehydes by the Selective Formylation of Polyarylamines
    GUO Can-Cheng, YIN Zhen-Ming, ZHANG Wei-Qiang
    2002, 23(9):  1719-1721. 
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    Synthetic method of asymmetry polyarylamino-benzaldehydes by the selective formylation of polyarylamines in Vilsmeier-Haack reaction was studied. Five polyarylamino-benzaldehydes, 4-N-methylphenylamino-benzaldehyde, 4-N-(n-butyl)-phenylamino-benzaldehyde, 4-diphenylamino-benzaldehyde, 4-N-phenyl-diphenylamino-benzaldehyde, 4-N-phenyl-(4′-diphenylamino)diphenylamino-benzaldehyde were synthesized by the selective formylation of the polyarylamines with POCl3 and DMFin the yields of 67%—92%. The structures of these aldehydes were characterized by MS, 1H NMR, IR. The studied results showed that the yields and selectivity of asymmetry polyarylamino-benzaldehydes were found to relate with the reaction time, structures of polyarylamines and the molar ratio of the reactants.
    The First Total Synthesis of Corylifin
    LI Ying, JIANG Guang-Ying, YUAN Hao, LU Biao, LI Yu-Lin
    2002, 23(9):  1722-1723. 
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    The first total synthesis of Corylifolin, starting from 4-methoxybenzaldehyde, was described. The key step is the alkylation of 4-methoxyphenylacetaldehyde with prenyl bromide mediated by chromium(Ⅱ).
    Preparation of Per-O-acetylated (S)-TBMB Carboxylic Acid Derivant of Methyl-4-amino-4-deoxy-D-glucopyranoside
    BAI Chen, LIANG Bo, WANG Shu-Zhen, ZHENG Xiao-Xun
    2002, 23(9):  1724-1726. 
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    Starting from D-galactose, per-O-acetylated (S)-TBMBcarboxylic acid derivant of methyl-4-amino-4-deoxy-D-glucopyranoside was prepared. The mechanism of the possible side reactions of the catalytic reduction from different types of azide sugar to the corresponding amino sugar was discussed. 1-O-Me-protection was selected for preventing the intramolecular dehydration of the 4-amino sugar, which was a key intermediate product in this synthetic process. The product was characterized by HRMS and 1H NMR spectroscopy and will be used as a molecular model to develop a new identification method of the D, L-configurations of amino sugar.
    The Quantum Chemistry Calculation Studies on Rearrangement, Ionization and Potential Energy Surface of B2H5 Radical and Cation
    SUN Yan-Bo, WU Di, LI Ze-Sheng, HUANG Xu-Ri, SUN Chia-Chung
    2002, 23(9):  1727-1730. 
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    Ab initio calculations for B2H5+ cation and neutral B2H5· radical have been performed at B3LYP/6-311G(d,p) and QCISD(T)/6-311+ +G(3df,2p)(single-point) level to give nine isomers, i.e. for B2H5+, there are two singlets(D3h, C1) and three triplets(Cs, C1, C1); for B2H5·, there are four singlets(C2v, Cs, Cs, Cs). The calculated results also give five transition states associated with the isomers. The adiabatic ionization potentials of the two B2H5· radicals(singly bridged C2v) and (doubly bridged Cs) are 6.84 and 7.65 eV, respectively. For the B2H5+, the energy difference between the most stable triplet state(singly bridged Cs) and the lowest singlet state(triply bridged D3h) is 4.72 eV. For the B2H5· and B2H5+ systems, the calculated results are in accordance with the experiments of R?s?i`?.
    Molecule Material Design of a Class of PAS and PPY Polymer with Nonlinear Optical Properties
    SU Zhong-Min, HU Li-Hong, YAN Li-Kai, WANG Rong-Shun, FENG Ji-Kang
    2002, 23(9):  1731-1734. 
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    Based on the three resonant structures of polybenzene(PAS), Polypyridine(PPY) and Polypyrazine(PPYZ), the nonlinear optical(NLO) coefficients of different conjugate monomer oligmers and substituted polymers were calculated. The results showed that the second-order NLOcoefficient of the polymer rises evidently comparing with that of its monomer. The NLOcoefficients of PAS, PPYand PPYZsubstituted by —NH2 and —NO2 have a remarkable increase based on the polymers, even reach more than two to three order of magnitude. The second-order NLOcoefficients of all kinds of PPYare all large in the unsubstituted polymers. The value β of PASsubstituted by single —NH2 and —NO2, especially the 2 —NH2 and 5 —NO2 substituted trans-resonance structure is as high as 3.27×10-27 esu. It indicates that PASsubstituted by —NH2 and —NO2 is a intriguing candidate of NLOmaterial.
    Effect of Hydrogen Gas Flow Rate on the Deposition of Diamond Films
    YANG Guang-Liang, WANG Li-Qiu, LÜ Xian-Yi, JIN Zeng-Sun
    2002, 23(9):  1735-1737. 
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    Thick diamond films have been deposited by Electron Assisted Hot Filament Chemical Vapor Deposition Method. The effects of hydrogen gas flow rate on the diamond films growth rate and diamond qualities have been studied. It is found that, with the gas flow rate increasing, in the range of 100 to 750 cm3/min, the diamond films growth rates increase while the diamond qualities get worse, and in the range of 750 to 1000 cm3/min the diamond films growth rates decrease whilethe diamond qualities are improved. Raman spectroscopy and Electron Paramagnetic Resonance has been used to detect the impurities of Nitrogen. The concentration of nitrogen in the diamond film decreases with the increase of gas flow rate, and it is 40 times higher in diamond films deposited at 100 cm3/min than that at 1000 cm3/min.
    Kinetic Studies on Catalytic Oxidation of CS2 over Atmospheric Particles
    WANG Lin, SONG Guo-Xin, ZHANG Feng, CHEN Jian-Min
    2002, 23(9):  1738-1742. 
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    Heterogeneous interaction between carbon disulphide and atmospheric particles was investigated by means of FTIR, XPS, TG-DTG-DTAand in situ XRDanalysis. COSand orthorhombic α-S8 were the main products at ambient temperature. And SO42- was identified on the surface of atmospheric due to the further oxidation of sulfur species. Based on the static-state FTIRstudy and the analysis of sulphur species on the surface of atmospheric particles by XPS, a model of mechanism on heterogeneous interaction between the surface of atmospheric particles and CS2 was given. The reaction is confirmed to be a pseudo-secondary one when O2 is overloaded. The apparent rate constant is 6.98×10-22 cm3·mol-1·s-1 at 296 K, and apparent activation energy is 34.6 kJ/mol. In an industrial zone with CS2 exhaust emission standard of 10 mg/m3(GB 3095), the CS2 wastage of the heterogeneous interaction is 41% of that of the reaction between CS2 and OH·, which confirms the significance of the heterogeneous interaction in developing countries.
    Investigation of the Factors Influencing the Process of Emulsification United Effect of cmc_O and cmc_W
    WANG Hai-Bo, LIU De-Shan 
    2002, 23(9):  1743-1747. 
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    The diameter and distribution of particles in the emulsion were investigated by means of the Mastersizer Microplus of Malvern. The results showed that with the addition of solvents such as toluene, trichloromethane etc., solubility of the surfactants in the oil phase was getting better, the diameter and distribution of the particles in the emulsion were becoming small and narrow. It is proposed that the united effect of cmco and cmcw is the key factor influencing the process of emulsification.
    Reactivity and Hydrocarbon Distribution of Novel Cobalt Catalysts Supported on Mesoporous Molecular Sieves for F-T Synthesis
    YANG Wen-Shu, GAO Hai-Yan, XIANG Hong-Wei, YIN Dong-Hong, YANG Yong, XU Yuan-Yuan, ZHONG Bing, LI Yong-Wang
    2002, 23(9):  1748-1752. 
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    Novel cobalt catalysts supported on MSU-1 and SBA-12 are developed for F-Tsynthesis in a fixed bed reactor, and the reactivity of Co/MSU-1 and Co/SBA-12 is compared with that of Co/HMS. It is found that the selectivity of C19+ hydrcarbon product for Co/MSU-1 and Co/SBA-12 is higher than that of Co/HMS and the chain propagation ability of Co/MSU-1 and Co/SBA-12 is higher than that of Co/HMS. The results of XRDand N2 adsorption-desorption show that the mesoporous structure of Co/HMS collapses after F-Tsynthesis, but that of Co/MSU-1 and Co/SBA-12 is partly kept, the relative stable mesostructure may be benificial to the product chain propagation.
    Chemistry of Borate(非汉字字符)——Crystallization Kinetics of Mg-borates from MgO·nB2O3-18%MgCl2-H2O Supersaturated Solution at 20 ℃
    ZHU Li-Xia, GAO Shi-Yang, HAO Zhi-Xian, XIA Shu-Ping
    2002, 23(9):  1753-1757. 
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    The MgO·nB2O3(n=1, 1.5, 2 and 3)-18%MgCl2-H2O supersaturated solution system were prepared and kept at 20 ℃. The crystallization processes of different hydrated Mg-borates from MgO·nB2O3-18%MgCl2-H2O supersaturated solution have been studied by kinetic method and the crystallization kinetic equations were fitted with the experimental data by computer. There were five solid phases, 2MgO·2B2O3·MgCl2·14H2O, 2MgO·3B2O3·15H2O, MgO·2B2O3·9H2O, MgO·3B2O3·7.5H2O and MgO·3B2O3·7H2O in the title system. All the solid phases were identified by IR-spectra, X-ray powder diffraction and TG-DTG-DSCthermal analysis.
    Studies on the Enantioselective Hydrogenation of Ethyl Pyruvate Catalyzed by γ-Al2O3 Support Rhodium Nanocluster/Quinine
    XIONG Wei, MA Hong-Xia, CHEN Hua, HUANG Yan-Yi, HUANG Yu-Lin, LI Xian-Jun, LI Xing-Shu, QI Jian-Ying, CHEN Xin-Zi
    2002, 23(9):  1758-1762. 
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    In the asymmetric hydrogenation of ethyl pyruvate catalyzed by Rh/PVPand Rh/PVP-γ-Al2O3, quinine as a chiral modifier can not only induce the enantioselectivity but also greatly accelerate the reaction rate.When nanocluster of Rh/PVPis supported on γ-Al2O3, the catalytic activity and enantioselectivity increase obviously. Comparing the turnover frequency(TOF) and enantiomeric excess of R-(+)-ethyl lactate(e.e. value) of Rh/PVPwith Rh/PVP-γ-Al2O3, the TOF and e.e. value rise by a factor of 10.6 and 2.03, respectively. The results indicate that γ-Al2O3 plays a very important role in the asymmetric hydrogenation for the accelaration of the reaction and promoting the increase of enantioselectivity. It is possible that γ-Al2O3 is fovourable for the dispersion of Rh/PVPon the support surface and inhibits the aggregation of Rh/PVP. Under the optimum conditions of 20 ℃, 7.0 MPa H2 and 3.86×10-3 mol/L of quinine concentration in tetrahydrofuran, TOFand e.e. value using Rh/PVP-γ-Al2O3 as catalyst can reach 871h-1 and 54.7%, respectively. When reaction temperature decreases to 3 ℃, the e.e. value increases to 59.2%.
    The Influence of pH on the Thixotropy of Ferric Aluminum Magnesium Hydroxide/Montmorillonite Suspension
    LI Shu-Ping, HOU Wan-Guo, DAI Xiao-Nan, Hu Ji-Fan, LI Dong-Qing
    2002, 23(9):  1763-1766. 
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    In this paper, we studied the influence of pHon the thixotropy of MMH/MTsuspension, and it was found that pHcould affect the type of thixotropy: when the mass ratio of MMHto MT(R) was relatively low(0, 0.012 and 0.051), with pHrising slowly, the suspension changed from negative thixotropy to complex thixotropy, then finally to positive thixotropy; when m(MMH)/m(MT) was relatively high(0.091), with pHrising gradually, the suspension changed from complex thixotropy to negative thixotropy. The mechanism of thixotropy is also discussed.
    Process Analysis and Mechanism of Multi-stage Hydropyrolysis of Coal
    LI Wen, WANG Na, LI Bao-Qing
    2002, 23(9):  1767-1771. 
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    The mechanism of multi-stage hydropyrolysis of coal was probed through detailed analysis of products of hydropyrolysis with different holding methods. The results showed that the holding method significantly affects the product distributions, thus making an apparent difference in hydrogen utilization efficiency. The holding temperature should be about 350—500 ℃ during which more free radicals are produced rapidly. Pore-riched structures are formed at the holding stage at 350 ℃ due to the evolution of large amount of volatiles, which is favorable to the subsequent hydrogenation reaction. The holding at a low temperature favors the reaction of hydrogen with oxygen-containing groups, leading to the formation of phenol and avoiding the formation of water at a high temperature. The cleavage of chemical bonds in the char is mainly dependent on the pyrolysis temperature. The effect of holding stage is to change the distribution and components of products via stabilizing the free radicals and hydrogenating the heavier products.
    A ZINDO-SOS Study on Nonlinear Second-order Optical Properties of 2-Phenylbenzothiazole and It′s Derivatives
    ZHANG Suo-Qin, FENG Ji-Kang, REN Ai-Min, LI Yao-Xian
    2002, 23(9):  1772-1775. 
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    The structures, UV-Vis spectra of 2-phenylbenzothiazole and it′s derivatives has been studied by using the ZINDOmethodology. The calculated UV-Vis spectra are in good agreement with the observed value. On the basis of ZINDOmethods, according to the sum-over-states(SOS) formula, the program for the calculation of nonlinear second order optical susceptibilities βijk and βμ has been devised, and the nonlinear second order optical properties of 2-phenylbenzothiazole and it′s derivatives has been studied by using this methodology. Compared with molecule 1, all of the derivatives have relative large nonlinear second-order optical susceptibilities. The calculation results show that with the increase of the push-pull effects the nonlinear second order optical susceptibilities increased. The electronic donating substituents attached to benzene ring and the electronic withdrawing substituents attached to benzothiazole ring are favourable for increasing the nonlinear second order optical susceptibilities. The structure that the electronic donating substituents attached to 13 position and the electronic withdrawing substituents attached to 6 position has the highest nonlinear second order optical susceptibilities βμ.
    Theoretical Study on the Formation Mechanism of Resonance State for Na+I2→Na++I2+ System
    CAI Zheng-Ting, MA Wan-Yong, SUN Xiao-Min, FENG Da-Cheng
    2002, 23(9):  1776-1777. 
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    An extended LCAC-SW(Linear Combination of Arrangement Channels-Scattering Wavefunction) quantum scattering dynamic method combined with ab initio quantum chemical calculations has been used to study the formation mechanism of the resonance states for ion-pair formation reaction Na+I2→Na++I2+. Resonance energy and width or lifetime for the first resonance peak were calculated. Resonance can be identified to Feshbach resonance and the physical interpretation was given.
    Direct Fabrication of Magnetite Nanoparticles Patterns via"Dip-Pen" Nanolithography
    HONG Xia, WEI Li, GUO Wei, LI Jun, SONG Wen-Long, BAI Yu-Bai, LI Tie-Jin
    2002, 23(9):  1778-1780. 
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    We use 8 nm magnetite nanoparticles as "ink", self assembly monolayer(SAM) of bovine serum albumin(BSA) as "paper" to generate arbitrary structures at micro or nanometer scales in the DPNprocedure. AFMand LFMare used to image the patterns. The height profile of pattern is about 8 nm, which is consistent with the diameter of magnetite nanoparticles. It means that the magnetic monolayer pattern has been obtained. The SAM of BSA is measured by diffuse reflection IRspectra and the data is coincided with the one of the literature. After writing the magnetite "ink", the band of magnetite appears at 570 cm-1 , which gives a further proof.
    Preparation of TiOy-SiOx Immobilized Pd-BMImCl Catalysts and Their Application in Carbonylation of Amines
    SHI Feng, MA Yu-Chun, ZHOU Han-Cheng, DENG You-Quan
    2002, 23(9):  1781-1783. 
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    Ahighly efficient Pd-BMImCl/TiOy-SiOx catalyst system synthesized through sol-gel method from palladium complex, ionic liquid, titanate and silicate esters was found for the oxidative carbonylation of amines. The catalyst efficiency was much higher than that reported in previous papers and the TOFnumber reached to 10372 when catalyst 0.05%Pd-4.6%BM ImCl/TiOy-SiOx was used. The usability of ionic liquid was the key point for preparation of this catalyst system because of its high dissolvability to palladium complex and affording appropriate micro-environment for the reaction. The synergism among palladium complex, ionic liquid, titanate and silicate was the main reason for the high catalytic activity of the catalyst system. BET, AESand XRDwere used to characterized the catalysts in detail.
    Preparation and Releasing Hydrogen Characteristic of Al2O3-Coated TiH2 Particles
    FANG Ji-Xiang, ZHAO Kang, GU Chen-Qing
    2002, 23(9):  1784-1786. 
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    The technique to prepare TiH2 coated with layers of Al2O3 particles by heterogeneous nucleation method with HAc-NaAc buffer solution as precipitation reagent was studied. The results show that the microscopic structure of Al2O3 coating layers depends on the pHvalue and Al3+ concentration range in the solution. The homogeneous and compact coating layers with Al2O3-coated TiH2 particles can be obtained at 0.05 mol/Land pH=4.5, after heating at 350 ℃. The hydrogen releasing of Al2O3/TiH2 particle is notably delayed with the increase of the temperature, and the delay effect can be used in the production of Al foams.
    Catalytic Performance of Perovskite Oxide Catalysts for Partial Oxidation of Methane to Syngas
    CHU Wen-Ling, YANG Wei-Shen, LIN Li-Wu
    2002, 23(9):  1787-1789. 
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    Ba0.5Sr0.5Co0.8Fe0.2O3-δ and 0.5Sr0.5Co0.8Ti0.2O3-δ oxides were synthesized by a combined EDTA-citrate complexing method. The catalytic behavior of these two oxides with the perovskite structure was studied during the reaction of methane oxidation. The pre-treatment with methane has different effect on the catalytic activities of both the oxides. The methane pre-treatment has not resulted in the change of the catalytic activity of BSCFOowing to its excellent reversibility of the perovskite structure resulting from the excellent synergistic interaction between Co and Fe in the oxide. However, the substitution with Ti on Fe-site in the lattice makes the methane pre-treatment have an obvious influence on the activity of the formed BSCTO oxide.
    Synthesis and Characterization of Nanocrystalline Materials MgSO4·5Mg(OH)2·3H2O
    YUE Tao, GAO Shi-Yang, ZHU Li-Xia, XIA Shu-Ping
    2002, 23(9):  1790-1791. 
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    Nanocrystalline MgSO4·5Mg(OH)2·3H2O were prepared by the hydrothermal reaction at 140 ℃ for 24 h. Nanoparticle samples were characterized by FTIR, TG, DSC, XRDand TEM. The size distribution of nanocrystalline is in the range of 10—20 nm, the mean size is 16 nm.
    Primary Study on Degradation Mechanism of Polystyrenesulfonic Acid Membrane and Its Composite Membrane in Fuel Cells
    YU Jing-Rong, YI Bao-Lian, XING Dan-Min, LIU Fu-Qiang, ZHANG Hua-Min, XU Qing, LIANG Xin-Miao
    2002, 23(9):  1792-1796. 
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    The lifetime behavior of the proton exchange membrane fuel cell(PEMFC) fabricated with polystyenesulfonic acid(PSSA) membrane was investigated in order to present the degradation mechanism of the PSSAmembrane. The water evacuated from the anode and the cathode of the cell during the lifetime experiment was analyzed by the method of high-performance liquid chromatogram. The distribution of Sconcentration in the cross-section of the PSSAmembrane was measured by energy dispersive spectrograph. Infrared spectroscopic measurements were carried out to investigate the structure of the PSSAmembrane before and after the fuel cell experiment. The degradation mechanism of the PSSAmembrane is indicated as that: during the fuel cell operation, the reduction of O2 gas at the cathode proceeds through a peroxide intermediate. H2O2 reacts with the trace metal ions in the cell to form HO·, HO2· and other oxidation radicals, which can chemically attack the tertiary hydrogen at the α-carbon of the PSSAmembrane. The degradation of the PSSAmembrane mainly occurs from the cathode of the cell. The loss of the aromatic ring and the SO3- group simultaneously occurs from the PSSAmembrane. A PSSA-Nafion composite membrane was prepared according to the above-mentioned degradation mechanism of the PSSAmembrane. The Nafion 101 membrane of 25 μm thickness is located at the cathode. The PEMFCwith the PSSA-Nafion composite membrane could be operated steadily for more than 800 hours without significant performance deterioration.
    Studies on Epoxy-acrylate Hybrid UV-cure System
    XIAO Shan-Qiang, CHEN Qi-Dao, CHEN Ming, HONG Xiao-Yin
    2002, 23(9):  1797-1800. 
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    We studied an epoxy-acrylate hybrid UV-cure system and demonstrated that the diaryliodonium salt can be sensitized by the free radical photo-initiators. The cured product of hybrid UV-cure system has better mechanical properties, such as hardness, bending strength, impact strength, etc., than those of the cationic product. The glass transition temperature (Tg) of hybrid- cured product is higher than that of the free-radical product. The solvent-resistance (double acetone rubs) of hybrid UVcured product is much higher than those of either free-radical product or cationic product. The excellent performance was attributed to the formation of interpenetrating polymer network (IPN), which was demonstrated by dynamic viscoelastic spectra and scanning electron microscope (SEM).
    Studies on Pervaporation Behavior of CA and Its Blend Membranes——Dependence of Permeation Flux on Viscosity Slope Coefficient
    QIAN Jin-Wen, MIAO Yi-Min, WANG Li-Na, ZHANG Lin, CHEN Huan-Lin
    2002, 23(9):  1801-1804. 
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    Viscosity behavior of cellulose acetate(CA) and its blends in different solvents has been studied. The pervaporation behavior of their membranes from the corresponding solvents has been measured for separating methanol/methyl ter-butyl ether(MeOH/MTBE) mixture. It was found that the permeation flux (J) of the membranes is reciprocal to the viscosity slope coefficient (b) in its dilute solutions.
    Aggregation and Photo-responsive Behavior of Azo Polyelectrolytes in Aqueous Media
    TUO Xin-Lin, WU Li-Feng, WANG Xiao-Gong 
    2002, 23(9):  1805-1808. 
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    The aggregation behavior of a series of side-chain azo polyelectrolytes (PPAPE) was studied in aqueous and tetrahydrofuran(THF)/water mixed media. The aggregate process was traced with UV-Vis absorption spectroscopy. The critical aggregate concentration(CAgC) of PPAPEin aqueous solution was determined by measuring the surface tension values of the related solutions with different concentrations. The self-assembled supermolecular structures were characterized with transmission electron microscopy(TEM). The results show that the azo chromophores tethered to PPAPE H-aggregate under a suitable condition and further aggregate into nanoscale structures. Following with the aggregation process, the(max obviously blue-shifts and the photochromic effect of azo chromophores is significantly weakened. Although the pHof aqueous solutions also have a significant effect on the photochromic effect, however, these two kinds of effects have obviously different mechanisms.
    Synthesis of 2-Polystyrylsulfonylethanol and Its Application in Solid-phase Organic Synthesis of Hydantoins and Ureas
    CHENG Shao-Ling, HUANG Wen-Qiang
    2002, 23(9):  1809-1813. 
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    In this article a new kind of polymer-support: 2-polystyrylsulfonylethanol was prepared and used in solid-phase organic synthesis. Sodium polystyrylsulfinate resin 1 reacted with chloroethanol in the presence of phase transfer catalyst Bu4NIand KIas a cocatalyst to give 2-polystyrylsulfonylethanol resin 2 After the esterification of resin 2 with Boc-Gly, deprotection of Boc group with HCl, neutralization by Et3N, conversion of the free amino group with phenyl isocyanate or phenyl isothiocanate to urea to give urea resin 6 The urea resins 6a and 6b were cleaved with 6 mol/L HCl to obtain the hydantoin derivatives 7a and 7b in an overall yields of 29%—30%. While the resin 6 was treated with 4 mol/L NaOHthen HCl to give the urea derivatives 8a and 8b in an overall yields of 20%—21%. The whole synthesis processes were optimized by the trace of the reactions by using IRspectra. The results show that resin 2 can easily form a stable ester linker with carboxylic acids and this kind of linker can be cleaved by the use of both strong acid or dilute base.
    Molecule-Design and Synthesis of Water-soluble Hyperbranched Copoly(ester-amine)s
    GAO Chao, YAN De-Yue
    2002, 23(9):  1814-1816. 
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    Water-soluble hyperbranched copoly(ester-amine)s with various degree of branching (DB) were prepared via the "A2+B2+BB′2" approach. Due to the faster reaction between Aand Bfunctional groups, the intermediate containing one Agroup and two B′ groups was generated in situ. Further self-polyaddition of the AB′2 intermediate gave hyperbranched polymer. In this communication, A2 is ethylene diacrylate (EDA), B2 is piperazine (PZ), and BB′2 is 1-(2-aminoethyl)piperazine (AP). The combination of mass spectrum and in situ FTIRdetermined the reaction mechanism and propagating paths predicted. DBof the resulting branched poly(ester-amine)s decreases with increasing the feed ratio of PZ to AP. In the same molecular weight, the inherent viscosity of the polymers presented here increases with decreasing DB. The simplicity of the reaction process, the controllability of the architecture, and the commercially availability of the raw materials would make this approach attractive in the large scale manufacture and application of hyperbranched polymer materials.
    Synthesis and Thermal Properties of Controllable Cross-linking Poly(ether ether ketone)s
    LIU Xin-Cai, CHEN Chun-Hai, CAO Hui, BEN Teng, GAO Zi-Hong, ZHAO Xiao-Gang, YU You-Hai, REN Dian-Fu, LI Zhi-Cheng, WU Zhong-Wen, ZHANG Wan-Jin
    2002, 23(9):  1817-1819. 
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    Anovel controllable cross-linking PEEK was synthesized by introducing thioether moieties into PEEKrigid chain, in which sulfur acts as a cross-linking point. It is found that the cross-linking reaction could take place at 623 Kover a period of 5 h. The novel material has an excellent thermal stability and mechanical properties. It can be processed as convenient as that of pure PEEKbefore cross-linking and has a high application temperature as thermosetting resin after cross-linking.
    Partially Disentanglement of Mono-dispersed Polypropylene and Its Property in the Melt
    SUN Qing, ZOU Ye-Kui, XUE Qi, XIAO Zheng-Gang, GAO Yun, HU You-Liang
    2002, 23(9):  1820-1822. 
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    When mono-dispersed polypropylene was recovered from liquid paraffin, a solvent of large molar size, at a concentration more than C*, partially disentangled polypropylene was obtained. The modified polypropylene has a relatively high crystallinity. Furthermore, it has a lower apparent viscosity(ηa) and shear stress(τ) than that of the control samples at the same shear rate(γ). The mechanical properties of the modified polypropylene are almost unchanged, which cannot be found in any other method of modifying the rheological properties of polymer.
    Preparation and Characterization of Polyurethane Molecular Stamps
    LIU Zheng-Chun, HE Quan-Guo, XIAO Peng-Feng, LIANG Bo, HE Nong-Yue, LU Zu-Hong
    2002, 23(9):  1823-1825. 
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    Polyurethane based on polypropylene glycol(PPG) and TDIusing 3,3'-dichloride-4,4'-methylenedianiline(MOCA) as the crosslinker is presented for the first time to fabricate molecular stamps(PU stamps) for the synthesis of DNA microarray with contact procedure. The predictability of the process is achieved by utilizing commercially available starting materials. SEM analysis of the morphology of PU stamps and photoresist motherboard showed that PUelastomer could replicate subtly the motherboard's patterns with a high fidelity. It was proved from the contact angle measurement that PU stamps surface has a good affinity with acetonitrile, which guarantee the well-distribution of DNA monomers on patterned stamps. Laser confocal fluorescence microscopy images of oligonucleotide arrays confirm that polyurethane is an excellent material for molecular stamps.
    STM Study of Polyimide LB Film and Its Pyrolyzed SiC Film
    JIN Bang-Kun, CONG Shu-Xin, HE Ping-Sheng 
    2002, 23(9):  1826-1828. 
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    The surface morphologies of polyimide LB film and the SiC film pyrolyzed from polyimide LB film were studied with STM technique. The results show that molecular chains of polyimide LBfilm are highly oriented in certain scale, the SiC film keeps the similar regular structure to that of polyimide LB film, suggesting that the SiC formation reaction proceeds on the basis of the lattice of polyimide molecules.