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Table of Content

    24 December 2002, Volume 23 Issue 12
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    Articles
    Preparation and Properties of Abzyme with Thyroxine Deiodinase
    SUN Li-Wei, LIU Li-Yan, ZHAO Da-Qing
    2002, 23(12):  2217-2220. 
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    The abzyme (Se-6E8) with a higher thyroxine deiodinase activity was prepared by modifying the serine residues of monoclonal antibody (6E8) with phenylmethanesulfonyl fluoride and sodium hydrogen selenide, and the 6E8 against O-methyl-T4, which is a kind of thyroxine derivatives and was taken as a hapten for the first time. Two bands were found corresponding to the 5.5 kD heavy chain and the 2.7 kD light chain respectively by SDS-PAGE. The characteristics of dissociation constants, pH, and temperature were also studied. The results show that the activity of Se-6E8 is 2010 U/μmol protein , and the proper temperature and pH of the catalytic reactions is 57 ℃ and 8.2 respectively.
    Synthesis and Characterization of Two Positional Isomeric Tetraamino-phthalocyanines Zinc(Ⅱ)
    CONG Fang-Di, DU Xi-Guang, ZHAO Bao-Zhong, LIU Qun, CHEN Bin
    2002, 23(12):  2221-2225. 
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    Two pure isomers, 2,9,16,23-tetraamino-phthalocyanine zinc(Ⅱ) and 1,8,15,22-tetraamino-phthalocyanine zinc(Ⅱ), have been prepared in two steps from 4-nitro-o-phenyleneimine and 3-nitro-phthalic anhydride respectively and without using chromatographic fractionation. The synthesized compounds were characterized by using 1H NMR MALDI-TOF MS and solution phase electronic (UV-Vis) spectroscopy. Dipolymers in their DMF solution and stability of their amino-group antioxidation were confirmed by mass spectroscopy. Amino-group kinetic stability in the former isomer molecule and thermodynamic stability and intra molecular hydrogen bond in the latter isomer molecule were concluded through discussing their 1H NMR and UV-Vis spectroscopy.
    Synthesis of Low-silica X-Zeolite via Crystallization Directing Agent Method
    CUI Yi-Cheng, HAN Dong-Cheng, FU Le-Feng, ZHANG Ai-Min, XU Qin-Hua, DONG Jia-Lu
    2002, 23(12):  2226-2229. 
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    Low-silica X-zeolite(LSX) with a molar ratio 2.0 of SiO2to Al2O3has been prepared by crystallization directing agent(CDA). The crystal structure was studied by XRD. The composition and crystal phases were detected by X-ray fluorescence spectrum and electron diffraction spectrum. LSX was synthesized quickly with a high crystallization by using the CDA method. The directing effect of CDA was consecutive in the synthesis. The effect of CDA is related to the composition of mixture, aging time and temperature, and it is related to the growth of the crystal faces.
    Mechanism of Gold Extraction from Cyanide Solution by Tetradecyldimethylbenzylammonium Chloride
    JIANG Jian-Zhun, ZHOU Wei-Jin, GAO Hong-Cheng, WU Jin-Guang, XU Guang-Xian
    2002, 23(12):  2230-2233. 
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    The mechanism of solvent extraction of gold from cyanide solution by quaternary ammonium salt, tetradecyldimethylbenzylammonium chloride(TDMBAC)/tri-n-butyl phosphate(TBP)/heptane was studied. The microstructure of complexes,[R4N+]·[Au(CN)2-]·4H2O·4TBP, in the organic phase was proposed based on hydrogen-bonding mechanism. Aggregations formed when gold (Ⅰ) mass concentration in the organic phase reached 3 g·L-1. The radii of aggregations were determined by dynamic laser scattering(DLS). During the extraction process, the complexes of TDMBAC and Au(CN)2- formed micelles in the aqueous phase. When cosolvent such as TBP was added to the aqueous phase, the complexes transferred into the organic phase and reversed micelles or microemulsion (W/O) were formed.
    Synthesis and Structure of a Novel 2D Network of Silver Complex with Di-Schiff Base Ligand
    OUYANG Xing-Mei, WANG Yan, LI Yi-Zhi, LIU Yong-Jiang, SUN Wei-Yin, TANG Wen-Xia
    2002, 23(12):  2234-2236. 
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    A new di-Schiff base ligand, 1,2-bis(3'-pyridylmethyleneamino)ethane(L), was designed and its Ag(Ⅰ) complex[Ag2(L)2](CF3SO3)2 was synthesized. The crystal structure analysis indicates that the complex crystallizes in monoclinic system, space group of C2/c with a=3.770 4(2) nm, b=0.797 90(10) nm, c=2.471 3(2) nm, β=101.840(10)°, V=7.276 5(12) nm3, Z=8, Dc=1.808 g/cm3, F(000)=3936, R=0.058 3, wR=0.076 6, (Δρ)max=0.657×103e/nm 3,(Δρ)min=-0.562×103e/nm3. It is interesting that one L ligand coordinates to three Ag(Ⅰ) atoms using four N atoms, while another L ligand connects two Ag(Ⅰ) atoms with three of four N atoms and one N atom keeps free of coordination.
    Comparative Investigation of Crystallization of Calcium Oxalate in Different Mimetic Systems
    OUYANG Jian-Ming, YAO Xiu-Qiong, ZHONG Jiu-Ping, XIE Yu-Shan, BAI Yu, KUANG Li, TANG Wen-Xia
    2002, 23(12):  2237-2239. 
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    The nucleation, growth and aggregation of calcium oxalate(CaC2O4) crystals were comparatively investigated in five different mimetic systems: water, NaCl solution, artificial urine, healthy urine and lithogenic urine by using scanning electron microscopy(SEM). The effects of original concentration of calcium ion and oxalate ion and crystallization time on the morphology, density and the size of CaC2O4 crystals were discussed. In lithogenic urine, calcium oxalate monohydrate(COM) crystals were the dominant phase. However, a mixture of COM and calcium oxalate dihydrate(COD) with a molar ratio of about 3∶2 was obtained in the healthy urine. COD has a less affinity for renal tubule cell surface, so COD is easy to be expelled out from body and there is a less probability of stone-forming in the healthy urine. The fastest nucleation and growth of CaC2O4 crystals were obtained in water and NaCl solution, respectively. The size of CaC2O4 crystals decreases in the following order: NaCl solution>artificial urine>lithogenic urine>healthy urine>water.
    Hydrothermal Synthesis and Structure of [Ni(en)2V6O14]n
    ZENG Qing-Xin, LI Hong-Fei, LI Ya-Feng, YANG Guo-Yu, XU Ji-Qing
    2002, 23(12):  2240-2242. 
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    A new complex[Ni(en)2V6O14]n was hydrothermally synthesized and characterized by 2-dimensional vanadium oxide framework pillared by Ni(en)2 group. Single crystal X-ray analysis indicates that this compound crystallizes in monoclinic system, space group P21/c with a= 0.892 17(18) nm, b= 1.711 1(3) nm, c=0.662 73(13) nm, β=111.58(3)°, V=0.940 8(3) nm3, Z=2, D c= 2.501 g/cm3, R=0.042 3, wR=0.060 9, S=1.006.
    Studies on Bonding Techniques for Poly(dimethylsiloxane) Microfluidic Chips
    YE Mei-Ying, FANG Qun, YIN Xue-Feng, FANG Zhao-Lun
    2002, 23(12):  2243-2246. 
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    In this paper the procedure was discribed for enclosing PDMS substrate containing microstructures with a flat piece of PDMS cover plate to fabricate PDMS microfluidic chips. The effects of proportions of PDMS prepolymer and curing agent, curing temperature and time on the bonding strength of PDMS wafers were investigated. The optimal mass proportions were 10∶1 for substrate and 5∶1 for cover plate. The optimal curing time for substrate and cover plate was 35-50 min and 25-40 min, respectively, at 75 ℃. The surface of the substrate and that of the cover plate seal tightly and irreversibly when brought into close contact and continue cured for 60 min at 75 ℃. The chips have been used successfully for the separation of two FITC labeled amino acids and worked well within a period of six months with more than 50 cycles of operations involving solution loading in the channel and channel washing.
    High-sensitivity Molecular Mass Determination of Lysozyme Prior to MALDI-MS
    SHI Lei, WANG Yong, LIU Zhi-Qiang, LIU Shu-Ying
    2002, 23(12):  2247-2249. 
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    Sodium dodecyl sulfate(SDS) is a powerful solubilizing detergent which is often used during the separation of highly complex protein mixtures by one- or two-dimensional(2D) gel electrophoresis. Matrix-assisted laser desorption/ionization mass spectrometry(MALDI-MS) is a widely used technique for mass spectrometric analysis of some protein molecules compared to other techniques. But the presence of SDS or some salts usually leads to signal deterioration when using MALDI-MS. A method for using nitrocellulose membrane as the solid-phase carrier combined with n-octyl-β-D-glucopyranoside in the matrix highly enhances the sensitivity of the molecular mass determination of lysozyme. This technique has the advantage that the signal-to-noise of the molecular weight profile is improved compared with the mass spectrum and the profile is relatively easy to interpret.
    High-resolution Hadamard Transform Microscopic Fluorescence Image Analysis(Ⅰ)──Imaging Capability and Quantitative Analysis on Single Tumor Cells
    TANG Hong-Wu, ZHOU Jin-Song, WU Qiong-Shui, CHEN Guan-Quan
    2002, 23(12):  2250-2252. 
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    The imaging capability(sensitivity, signal-to-noise ratio, imaging speed and spatial resolution) of a domestic-made high-resolution Hadamrd transform(HT) microscopic fluorescence imaging system was discussed. The results show that the system can be applied for high-resolution single-cell imaging sensitively in a short time, the cell image provided by the system has a high-resolution up to 511×512 pixel. The results also shows that this system has a more excellent resolving power than conventional optical microscope, under a 100× objective(oil lens) the spatial resolution up to 0.24 μm per pixel in X direction was obtained, which is close to the resolution limit of conventional optical microscope. The system was used for multi-parameter evaluation of breast tumor malignancy and malignant grade for a single tumor cell based on nuclei DNA ploidy measurements, and satisfactory results were obtained.
    Interaction Between Safranine T and Yeast DNA and Fluorescence-quantitative Determination of DNA
    YE Bao-Fen, ZHU Yong-Lin, JU Huang-Xian
    2002, 23(12):  2253-2255. 
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    The interaction between safranine T(ST) and yeast DNA was studied by means of UV absorption and fluorescence spectrometry. The wavelengths of fluorescence excitation and emission of ST were 520 nm and 570 nm, respectively. The maximum absorption of UV spectrum was at 520 nm. Two kinds of interaction between ST and DNA, intercalation and electrostatic interaction, were conformed. The binding site size in DNA base pairs was 14.5±1.5 and the apparent binding constant was (2.81±0.11)×104mol-1·L. The fluorescence quenching constant of DNA to ST was (1.52±0.19)×104mol-1·L. A novel fluorescence analysis for DNA determination was presented and the effects of experimental conditions on the fluorescence quenching were discussed.
    Theoretical Study on the Mechanism of Gaseous Phase Photochemical Chlorination of Pyridine──The Transition State and IRC Analysis of Abstracting Hydrogen Mechanism
    WANG Wan-De, YANG En-Cui, HAO Jin-Ku, ZHAO Xiao-Jun, CAO Ying-Yu, HAN Xiao-Yan
    2002, 23(12):  2256-2260. 
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    The abstraction hydrogen mechanism of pyridine reacted with chlorine radical consists of two elementary reactions. Both elementary reactions were studied of leading to three chlorinated products, searching for the TS location, calculating and comparing the activation barriers. The result show that the activation barrier of leading to 2-chloropyridine was the lowest of the three paths, the activation barriers of the two consequent elementary reactions were 8.33 and 1.51 kJ/mol, respectively, so 2-chloropyridine was the prior product. And the bond order, the net charge and IRC along ortho-path were also analyzed.
    Synthesis and Herbicidal Activity of 3-Aryloxy-6-substituted Pyridazines
    YANG Hua-Zheng, WANG Xiang, HU Fang-Zhong, YANG Xiu-Feng
    2002, 23(12):  2261-2263. 
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    A series of 3-aryloxy-6-substituted pyridazines have been synthesized and their herbicidal activity have been studied. All of above pyridazines have been confirmed by 1H NMR and elemental analyses, and some of them have been characterized by IR and MS. The bioassay result indicated that some of the title compounds have a high herbcidal activity. In addition, the structure-activity relationship was discussed.
    Configuration, Conformation and Crystal Structure for Taibaihenryiin C
    LI Bao-Lin, YU Kai-Bei, PAN Yuan-Jiang
    2002, 23(12):  2264-2267. 
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    Relative configuration, conformation and crystal structure for Taibaihenryiin C(1) isolated from Isodon henryi was elucidated on the basis of the single-crystal X-ray diffraction analysis. The X-ray crystal structure showed that the hydroxyl at C-3 and the acetoxyl at C-11 were in the β-orientations, respectively, and ring A is in a chair conformation, rings B and C approximate in the boat conformations, ring D approximates an envelope conformation in compound 1, respectively. A bigger tensile force existing in ring D suggests that this compound is a potential bioactive diterpenoid. The crystal of compound 1 is in orthorhombic crystal system, space group P212121, accurate lattice constants: a=0.616 2(1) nm, b=1.273 0(1) nm, and c=2.519 3(3) nm, Z=4. The molecules arrange in a screw structure along a axis in the crystal resulted from intermolecular hydrogen bonds through the hydrogen atom of the hydroxyl at C-3 to the oxygen atom of the acetoxyl at C-11.
    Research of Syntheses, Conformation and Identification Properties of p-tert-Butylcalix-1,4-2,5-bis-crown
    YANG Fa-Fu, CHEN Yuan-Yin
    2002, 23(12):  2268-2271. 
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    By reacting calix-1,4-crowns with triethylene glycol ditosylates or 1,2-bis-tosyloxyethoxybenzene in NaH/DMF system, a series of new type of calixcrowns: p-tert-butylcaix-1,4-2,5-bis-crowns were synthesized in high yields of 70%, and it is found that this stepwise method is very effective for the syntheses of calix-bis-crowns. The conformations of the obtained calix-bis-crowns were discussed in detail and the third stable conformation of calixarene besides cone and 1,2,3-alternate conformation-1,4-alternate conformation was obtained. It was found that the identification properties of this calix-bis-crowns are utterly different from that of the analogous calixcrowns and compound 2b exhibits a high complexation selectivity towards n-PrNH3+.
    Molecular Recognition of Several Model Substrates by Polyamine Modified β-Cyclodextrins and Their Complexes with Copper(Ⅱ)
    ZHAO Yan, LI Li, LIU Yu
    2002, 23(12):  2272-2277. 
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    The spectrophotometric and spectrofluorometric titrations have been performed to give the stability constants for the supramolecular systems formed by β-cyclodextrin(1), mono [6-(ethylenediamine)-6-dexoy]-β-cyclodextrin(2), mono[6-(diethylenetriamino)-6-dexoy]-β-cyclodextrin(3), mono [6-(triethylenetetraamino)-6-dexoy]-β-cyclodextrin(4) and their copper(Ⅱ) complexes(5, 6, 7) with some dyes in phosphate buffer solution(pH 7.2, 0.1 mol/L) and hydrochloric acid-potassium chloride buffer solution(pH 2.0, 0.1 mol/L) at 25 ℃. The results obtained indicated that the fluorescence intensity of RhB decreased with increasing concentration of native β-CD(1) and its derivatives(2-7), while the fluorescence intensity of other guest molecules simply increased with increasing concentration of host compounds. As compared with parent β-cyclodextrin, the stability constants of the formed inclusion complexes by copper(Ⅱ) complexes of polyamine modified β-cyclodextrins and protonated polyamine modified β-cyclodextrins were found to be increased by electrostatic interaction. The molecular recognition mechanism is discussed from the viewpoint of the size/shape matching between guest molecular structures and host cavity
    Analysis of Genetical Structure of the Ancient Xinjiang Population
    CUI Yin-Qiu, DUAN Ran-Hui, ZHOU Hui, ZHU Hong
    2002, 23(12):  2278-2280. 
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    MtDNA was successfully extracted from 31 ancient individual bones at the tombs of Turfan basin and Lubunouer. Through four overlapping primers, we got 30 nucleotide sequences of 363 bp length. Intermediate nucleotide diversity, and genetic distances, as well as mean pairwise variance, are compatible with ancient Turfan mtDNA pool being an admixture of eastern Asian and European lineages. Such phenomenon shows that prior to the time of ancient Turfan, an ancient mingling of Euro-Asian population in Turfan basin had existed. The ancient Luobunuoer was the relic of Xinjiang that was found in the earliest time and at the farthest orient. The mtDNA sequences of ancient Luobunuoer are consisted by European lineage completely, no trace of mixture with Asian lineage. From nucleotide diversity, and genetic distances and mean pairwise variance, it has close relationship with European populations.
    Studies on the Inclusion Property of 5,11,17,23-Tetra-tert-butyl-25,26, 27,28-tetrakis[3-(methoxycarbonyl)benzyloxy]calixarene
    ZHOU Zhi-Xian, SHI Ya-Lin, DU Chen-Xia, XING Yan-Jun, WU Yang-Jie
    2002, 23(12):  2281-2283. 
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    The synthesis of a novel host blocked in the cone conformation and bearing m-methoxycarbonylbenzyl groups at the lower rim is described. X-ray crystal structure analysis revealed that action of one molecule of compound upon one molecule of CH3CN or one molecule of CH3NO2, forms an intramolecular inclusion complex, respectively, by CH3-π interactions. The complex of L with tetrabutyl ammonium bromide(TBAB), L·TBAB, was obtained. The results of DTA-TG and XRD analysis of L·TBAB can also be considered as an intramolecular inclusion complex.
    Synthesis and Spectroscopic Analysis of 2',3'-O-Ethoxymethylidene Adenosine 5'-Thiophosphoramidates
    MIAO Zhi-Wei, FENG Yu-Ping, FU Hua, TU Guang-Zhong, ZHAO Yu-Fen
    2002, 23(12):  2284-2286. 
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    Nucleoside reverse transcriptase inhibitors are the only drugs so far approved for the treatment of AIDS. Several nucleoside analogs are potent inhibitors of human immunodeficiency virus(HIV) in cell culture. However, in many cases the nucleoside derivatives have a poor affinity for nucleoside kinases. Nucleoside 5'-phosphorothioates is relatively resistant to enzymatic transformations. In this paper, 2',3'-O-alkoxymethylidene adenosine 5'-thiophosphoramidates were synthesized through a highly efficient approach. The new compounds were characterized by NMR, IR and ESI-MS.
    Existence States and Activities of ZnPcSP as Photosensitizer Against Cancer in Solutions
    HUANG Jian-Dong, LIU Er-Sheng, YANG Su-Ling, XUE Jin-Ping, CHEN Nai-Sheng, HUANG Jin-Ling
    2002, 23(12):  2287-2291. 
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    The sulfonated phthalimidomethyl phthalocyanine Zinc(ZnPcSP) is an amphiphilic photosensitizer against cancer. The characteristic absorption peak of monomer and aggregate of ZnPcSP were observed, and the effects of solution compositions on its aggregation were investigated. In 70% MeOH/H2O, 70% EtOH/H2O, 50% EtOH/H2O, 70% i-PrOH/H2O, 70% CH2OHCHOHCH3/H2O, 50% DMSO/H2O, 50% DMF/H2O(volume fraction) and CEL solutions, ZnPcSP existed in the equilibrium between monomer and dimer, the dimerization constants were 1.314×105, 8.496×104, 9.753×104, 5.583×104, 3.809×105, 4.430×103, 8.679×103 mol/L, respectively. But trimerization of ZnPcSP took place in water and saline solution, and trimerization constants were 1.296×108 and 2.236×108 mol-2·L 2 respectively. Furthermore, the effect of existence states of ZnPcSP on the activities against S180 carcinoma were estimated. The result showed that the inhibitory rate of ZnPcSP(3.1×10-6 mol/L) in CEL solution mainly existing in the form of monomer was about 8 times higher than that of ZnPcSP in saline solution mainly existing in the form of trimer.
    Studies on the Relationship Between Structure and Properties of New Second-order Nonlinear Optical Hybrid Material
    LI Xu-Hua, YUAN Qiao-Long, WANG De-Ning
    2002, 23(12):  2292-2295. 
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    A new type of organic chromophore group/SiO2-TiO2 second-order nonlinear optical(NLO) materials has been obtained by sol-gel process. The research by X-ray energy dispersion spectrum(EDS) and Transmission electronic microscope(TEM) shows that the hybrid sol particles consist of SiO2, TiO2 and the organic chromophore group, and the size of the particles is about 20-80 nm. The second-order nonlinear optical polarizability χ(2) of the poled hybrid films is 1.43×10-7 esu according to one dimensional rigid oriented gas model(1DROGM). The poled film exhibits a good orientation stability, and its glass transition temperature can reach 469 K. The crystallization and micro-structure of hybrid films were analyzed by X-ray diffraction (XRD) and atom force microscope(AFM), and the mesostructure was discovered in the NLO hybrid films.
    Synthesis and Crystal Structures of Tetraethyl Ammonium Inclusion Complex with Urea, Fumarate and Water Molecules as Anionic Host Lattice Building
    ZHANG Jin-Nan, YE Ling, ZHENG Xiao-Yan, LI Qi
    2002, 23(12):  2296-2299. 
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    A new inclusion complex, (C2H5)4N+[C4H2O42-] 1/2·CO(NH2) 2·H2O, has been prepared and characterized by X-ray crystallography. Crystal data: space group C2/c(No.15), a=1.790 9(5) nm, b=1.443 1(4) nm, c=1.444 3(3) nm, β=126.76(2)°, V=2.990 5(13) nm3, Z=4, F(000)= 1 168, μ=0.09 mm-1, R1=0.064 7 for 2 088 observed Mo Kα data (|F|2≥2.0σ|F|2). In the crystal structure of the title compound, two urea molecules are linked by a pair of N-H...O hydrogen bonds in the usual shoulder-to-shoulder manner to generate a dimer. These hydrogen-bonded urea dimers are alternately linked by additional pairs of N-H...O hydrogen bonds to form an approximately planar ribbon oriented parallel to the c axis. Bridged alternately by donor O(W)-H...O hydrogen bonds from the water molecules, the fumarate anions form a zigzag wide ribbon running parallel to the c axis. The parallel, alternate arrangement of these two kinds of complementary ribbons facilitates cross-linkage by N-H...O hydrogen bonds to form a puckered anionic layer normal to b axis. The title complex features a sandwich-like structure in which the tetraethylammonium cations occupy the space between urea-fumarate-water layers.
    Experimental Studies on Effect of Concentration of CS2 on Linewidth and Frequency Shift of Raman Spectrum
    YIN Jian-Hua, GAO Shu-Qin, XU Xin-Feng, LI Zuo-Wei
    2002, 23(12):  2300-2302. 
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    Liquid-core optical fiber technique applied in the measurement of Fourier transform Raman spectra, can enhance the Raman spectral intensity about 102-104 times. Applying this technique, we researched the effect of the variation of the concentrations on the linewidths and frequency shifts of Raman spectral line of β-carotene and rhodamine(in CS2) in relation to the transition of π-π* of C=C bond. The experiment results showed that the red shift happens to the peak value of Raman spectral line, linewidth becomes narrow with the decrease of concentration when the concentration studied is 10-7-10-12 mol/L.
    Surface Enhanced Raman Scattering(SERS) Studies on Adsorption Orientation on Self-assembled DNA
    DONG Li-Qin, ZHOU Jian-Zhang, WU Ling-Ling, DONG Ping, LIN Zhong-Hua
    2002, 23(12):  2303-2308. 
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    A detailed study is conducted for the electrochemical ex situ and in situ surface enhanced Raman scattering(SERS) studies of oligonucleotide probe self-assembled monolayer on gold substrate before and after hybridization. Ex situ SERS results indicate that dsDNA molecules on gold substrate are not only in B-form but also in A-form helices and that the DNA molecules have the adsorption orientation change after the hybridization. According to the in situ SERS results, the intensities of most of the SERS bands of ssDNA and dsDNA decrease substantially toward more positive potentials, especially for two out-of-plane vibration modes of adenine. By utilizing SERS "surface selection rules", it can be concluded that as the potential is progressively changed from negative to more positive potentials, the adsorption orientation of ssDNA and dsDNA changes from standing straight up to lying flat down on the gold substrate.
    Homogeneous Catalytic Synthesis of Ethylene Carbonate Under Supercritical Condition
    LU Xiao-Bing, ZHANG Hua, HE Ren
    2002, 23(12):  2309-2312. 
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    Tetradendate Schiff-base aluminum complexes were prepared and used as the catalysts for synthesizing ethylene carbonate from supercritical CO2 and ethylene oxide mixture. Among them, SalenAl(OCH2CH2)3Cl, possessing a long oxyethylene chain, was found to be more effective. Because of high miscibility of ethylene oxide in supercritical CO2 under employed conditions, the cycloaddition of CO2 with ethylene oxide under a supercritical condition shows a higher rate than that under a non-supercritical condition. The catalytic activities of these aluminum complexes can be markedly enhanced in the presence of a Lewis base, such as 1-MeIm. Also, the possible catalytic mechanism was proposed, based on some spectral data at a low temperature.
    EPR Measurement of Hydroxyl Radicals and Rate Constant of n-Hexadecane Photocatalytic Degradation
    ZHONG Ping, KONG Ling-Ren, LIU Guang-Ming, SUI Yun-Xia
    2002, 23(12):  2313-2316. 
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    Spin trapping technique was used to detect the free radicals formed upon light irradiation of TiO2 in aqueous solutions. 5,5-dimethylpyrroline-N-oxide(DMPO) was used as a spin trapper. The Electron paramagnetic resonance( EPR) signal obtained 1 min after reaction initiated by 180 W mercury lamp irradiation with a mixture of 1 g/L TiO2, 0.05 mol/L DMPO in phosphate buffer(pH=7.4) gave the 1/2/2/1 quartet with hyperfine splittings of a N=a H=1.49×10-3 T, g=2.005 0, which were typical peaks of DMPO-OH. A model was used to speculate on the free radical mechanisms of n-hexadecane photodegradation by TiO2 in aqueous solutions. The intensity increased with increase of the irradiation time and the steady state was achieved at 1 min light irradiation. By employing the known rate constant for the reaction of hydroxyl radicals(HO ·) with the DMPO, the rate constant k=5.0×1011 mol-1·L·s-1 for the reaction of hydroxyl radicals with n-hexadecane could be obtained. In conclusions, TiO2 photocatalytic reaction proceeded in a free radical mechanism.
    Preparation of Iron-doped TiO2 Nanocrystal by Hydrothermal Method and Its Photocatalytic Properties
    YAN Peng-Fei, ZHOU De-Rui, WANG Jian-Qiang,YANG Li-Bin, ZHANG Di, FU Hong-Gang
    2002, 23(12):  2317-2321. 
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    Nanosize Fe3+-doped TiO2 particles were prepared by the hydrothermal method with TiCl4 as the precursor. The products obtained under different conditions were characterized by means of XRD. The influences of various hydrothermal conditions including reaction time, temperature, and pH were investigated. The photocatalytic activity of the catalysts was tested with Rhodamine B as the objective decomposition substance. The results show that the 0.1%Fe3+-doped TiO2 has a higher photocatalytic activity than TiO2.
    Effects of Al Doping on the Spinel Structure of Li2O4
    GONG Jie, YANG Jing-Hai, WANG Chun-Zhong, WEI Ying-Jin, ZONG Zhan-Guo, CHEN Gang
    2002, 23(12):  2322-2324. 
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    The mixtures of Al(OH)3 and Mn3O4 with different molar ratios, x[x=n(Al)∶n(Mn+Al)=0, 0.025, 0.050, 0.10, 0.150, 0.20] were prepared by the coprecipitation method. The mixtures were sintered at 700 ℃ after mixed with LiNO3. The XRD and Raman results show that the mixtures are the single phase spinel Li[Mn(Al)]2O4 with Al content, x, between 0 and 0.20. The crystal parameter decreases, the lattice vibration energy increases, the bond of Mn(Al)-O becomes stronger, and the structure stability is enhanced when Al content increases.
    In situ Diffuse Reflectance FTIR Study on Water in Lignite
    LI Dong-Tao, LI Wen, LI Bao-Qing
    2002, 23(12):  2325-2328. 
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    With a new method of diffuse reflectance FTIR(DRIFT)(using the single channel spectrum of dry coal at 140 ℃ as the background), the water in two lignites was studied for the first time. The results show that the content of water is directly proportional to the integral area of the corresponding wave number range in the spectra of the water remained. Based on the calculated hydrogen bonding energy of the water in dry coal, the water-coal interaction(hydrogen bonding) was discussed. Moreover, according to the research result of DRIFT, the water in coal was classified into two forms: one is the free water or the water which is weakly hydrogen-bonded with coal and mainly removed below 80 ℃; and the other is the water tightly bound with coal surface through strong hydrogen bonding, which is removed above 80 ℃.
    Studies on Mechanism of Methanol Decomposition over Pd/CeO2 Catalyst
    YANG Cheng, DONG Qing-Nian, REN Jie, SUN Yu-Han
    2002, 23(12):  2329-2331. 
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    The interaction between hydrogen and CeO2 support and Pd/CeO2 catalysts is characterized by TPR and H2-TPD, while the adsorption and decomposition of methanol over CeO2 and Pd/CeO2 catalysts were studied by in-situ FTIR technique, then a new model of the mechanism for the methanol decomposition over Pd/CeO2 catalyst was proposed. It was found that the lattice oxygen of CeO 2 was active towards oxidation of the adsorbed methanol to form formate species, which were then reduced by the hydrogen produced and activated on Pd. The anion Cl- promoted the interaction between hydrogen and Pd/CeO2 catalyst, so a synergistic effect between Pd and CeO2 was proved by their action of lattice oxygen and hydrogen.
    Prepararion of Highly Active Esterification Catalyst SBA-15 Mesoporous Silica Functionalized with Sulfonic Acid Group
    YUAN Xing-Dong, SHEN Jian, LI Guo-Hui, ZHOU Jing-Lai, KIM Ji-Man, PARK Sang-Eon
    2002, 23(12):  2332-2335. 
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    Well-ordered, mesoporous, hybrid SBA-15 materials containing alkyl(methyl) and sulfonic acid group were prepared by post and direct-synthesis methods in the presence of triblock copolymer P123 as the structure-directing agent under acid conditions. The materials have been characterized by powder X-ray diffraction,nitrigon gas sorption(BET), FTIR, themogravimetric weight loss(TGA) and solid state 29Si MAS NMR. XRD result shows the two kinds of catalysts have the SBA-15 structure characters (hexagonal, p6mm). FTIR and 29Si-MAS-NMR results show the surface of SBA-15 functionalized by the organic-silica group and the acid site is B acid site. BET shows them has a large surface area and large pore size. TGA shows they have a higher thermal stability than sulfonic acid resin. They are efficient catalysts for the esterification of methanol with oleic acid. The d-SBA-15-SO3H catalyst has a higher hydrothermal stability and hydrophobicity than p-SBA-15-SO3H. The d-SBA-15-SO3H can be reused many times, and the activity can retain stable. The direct synthesis method is more simple, convenient and efficient comparison with the post synthesis method.
    Statistical Mechanics and Dynamics of Hyperbranched Polymerization of ABg Type
    HONG Xiao-Zhong, WANG Hai-Jun, ZHAO Bao-Hui, ZHAO Min, BA Xin-Wu
    2002, 23(12):  2336-2339. 
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    We have theoretically investigated the statistical mechanics and dynamics of the hyperbranched polymerization of ABg type, a relationship between the conversions of the two species and the Gibbs free energy is obtained, which makes the characterization of the polymer physical quantities can be simplified. Furthermore, the relationship between the dynamics and statistical mechanics of the system under study is pointed out, and then the conversions of the two species as a function of time is derived. Based on the results obtained in this paper, the hyperbranched polymerization can be investigated in a deeper level.
    Influence of Donor/Acceptor Substitutions on the Properties of Photo-electricity in PPV-like Electroluminescent Polymers
    HUANG Zong-Hao, DUAN Xue-Mei, KAN Yu-He, KANG Bo-Nan, SU Zhong-Min, TANG Qian-Lin, DU Guo-Tong
    2002, 23(12):  2340-2343. 
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    The electronic properties and energy band structures of PPV, MEH-PPV and CN-PPV were calculated by quantum chemistry method, AM1 and EHMACC/CO, respectively. The influence of photo-electricity on PPV-like electroluminescent polymers substituted by alkyloxy(-OR) and cyano(-CN) were discussed. The result indicates that HOCO level(highest occupied crystal orbital) of polymer is raised by electron-donor(-OR) substitutions and the ionization potentials is decreased, while LUCO level(lowest unoccupied crystal orbital) is lowered by the electron-acceptor(-CN) substitution and electron affinities is increased. The band gap of polymer is decreased in both cases. At the same time, conducting type is changed from p type of PPV to n and p compatibility type of CN-PPV. The red shift of spectrum of MEH-PPV and CN-PPV and the higher electroluminescence efficiency of CN-PPV were explained. Our calculation is significant for designing new type PPV-like polymers with a high electroluminescence efficiency.
    Theoretical Studies on Mechanism of NH2(X2B1) and CH4
    SUN Ren-An, JIN Fei, SUN Yan-Bo, TAO Zhan-Liang, HAN Ke-Li
    2002, 23(12):  2344-2347. 
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    The mechanisms of the reaction NH2+CH4→NH3+CH3, NH2+CH4→CH3NH2+H have been studied at B3LYP/6-311G* level of density functional theory. The transition states of the two reaction paths are obtained and verified by the analysis of vibration and internal reaction coordinate(IRC). Furthermore, we obtained the energy barriers of two reactions with QCISD(T)/6-311G* and are corrected by zero-point energy. The information along the two reaction paths was gained. It is found that the reaction NH2+CH4→NH3+CH3 is main reaction pathway.
    Direct Dynamics Studies for the Reaction Si+HCl→SiCl+H
    LIU Jing-Yao, SUN Yan-Bo, HUANG Xu-Ri
    2002, 23(12):  2348-2350. 
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    Ab initio direct dynamics method is employed to study the dynamics of the reaction Si+ HCl→SiCl+H. The potential energy surface(PES) information is obtained at the QCISD/ 6-311+G(d,p) and CCSD(T)/aug-cc-pvtz (single-point) levels. The rate constant as well as its temperature dependence is evaluated by using variational transition state theory. The calculated results are in good agreement with the available experimental values.
    Microwave Assisted Photocatalytic Oxidation and Its Applications
    LI Dan-Zhen, ZHENG Yi, FU Xian-Zhi 
    2002, 23(12):  2351-2356. 
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    In this paper, the present situation and progress of microwave application in the area of semiconductor photocatalysis were reviewed briefly, including the mechanism of semiconductor photocatalysis, the preparation of photocatalyst by using microwave method and the microwave-assisted photocatalytic oxidation reactions. The coupling effect of microwave and ultraviolet for increasing the quantum efficiency of photocatalytic oxidation was discussed.
    Preparation of Au/Ag Core-shell Nanoparticles and Its Surface-enhanced Raman Scattering Effect
    JI Xiao-Hui, WANG Lian-Ying, ZHANG Xin-Tong, BAI Yu-Bai, LI Tie-Jin, ZHI Zhuang-Zhi, KONG Xiang-Gui, LIU Yi-Chun
    2002, 23(12):  2357-2359. 
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    We prepared Au/Ag core-shell nanoparticles by growing Ag shell onto 12 nm Au core, using silver nitrate and sodium citrate as the reactants. By changing the molar ratio of Ag to Au, the shell thickness and thus the size of bimetallic particles could be controlled in convenient way. The formation of core-shell structure was proved by UV-Vis spectra, transmission electron microscopy(TEM), etc.. The core-shell particles showed a more narrow size distribution than Ag colloid prepared without Au core. The SERS activity of the core-shell particles was investigated by using 2,4-dimethylpyridine as the probe, which strongly indicated their potential application in SERS substrate materials.
    UV-Vis Absorption Study of Vacuum Vapor Deposited Lead Phthalocyanine and Vanadyl Phthalocyanine Nanometer Multilayered-film
    RUI Xiang-Xin, JI Zhen-Guo, WANG Long-Cheng, WANG Mang, Yasukiyo Ueda
    2002, 23(12):  2360-2362. 
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    Nanometer multilayer composite films of lead phthalocyanine(PbPc) and vanadyl phthalocyanine(VOPc) were prepared by vacuum vapor deposition. It is found that a new absorption peak around 940 nm appeared as discovered by UV-visible absorption analysis. Compared to the Q bands absorption of single component films of VOPc and PbPc, the new peak is red-shifted. It is also found that the new peak shows a small red-shift when the thickness of the PbPc layer increases. It is concluded that the new peak is a result of composition, and the red-shift is caused by both interface effect and quantum confinement effect of the nanometer multilayered structure.
    TBAB-modified Supported Wacker-type Catalysts for Highly Selective Oxidative Carbonylation of Methanol to Dimethyl Carbonate
    WANG Shao-Cheng, CAO Yong, YANG Ping, HU Jian-Guo, WU Dong, SUN Yu-Han, DENG Jing-Fa
    2002, 23(12):  2363-2365. 
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    A novel tetrabutyl ammonium bromide(TBAB) modified Wacker-type catalyst system supported on various supports has been investigated in the gas-phase oxidative carbonylation of methanol and CO for dimethyl carbonate(DMC) synthesis. It is demonstrated that the SiO2 supported Wacker-type catalysts have shown the best catalytic performance for DMC synthesis in terms of the activity and selectivity.
    The Effects of Divalent Metal Ions on the Thermal Stability of Salmon Sperm DNA
    WU Rui-Guang, YU Zhi-Wu, CHEN Lin, ZHOU Rui
    2002, 23(12):  2366-2368. 
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    The effects of Mg2+, Ca2+, Mn2+, Co2+ and Ni2+ on the thermal stability of Salmon Sperm DNA were investigated by employing differential scanning calorimetry method. For the divalent cations, the shielding effect plays the dominant role in the interaction of nucleic acid chains when they are in low concentrations, as reflected in the moderate increasing of DNA melting temperature. Along with increasing concentration, both alkaline earth metal ions and transitional metal ions were found to lower the DNA melting temperature, indicating possible direct interaction between the divalent cations with the bases in the DNA molecules. The effectiveness increases with the order Mg2+, Ca2+, Mn2+, Co2+ and Ni2+. It was found for the first time that the presence of Mn2+ triggered the biphasic-melting behavior of the Salmon Sperm DNA when the concentration of the cation was increased to a value about 2 times of phosphorous in DNA.
    In-situ Albumin Binding Material for Biomedical Application(Ⅱ)── Albumin Selectivity and in vitro Hemo-compatibility
    JI Jian, FENG Lin-Xian, SHEN Jia-Cong
    2002, 23(12):  2369-2374. 
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    In order to assess the hypothesis that the composite structure of srearyl group and PEO might exhibit albumin preferential adsorption by both the albumin bonding affinity of stearyl groups and the protein-resistant character of EO side chains, the adsorption of plasma proteins(fibrinogen and albumin) from buffer and plasma onto poly(methylmethacrylate-co-stearyl-methacrylate)(PMMA-co-SMA), polymethylmethacrylate)-graft-[ω-stearyl-poly(ethylene oxide)](PMMA-g-SPEO) and poly(methyl methacrylate)-graft-[ω-ethyl-poly(ethylene oxide)](PMMA-g-EPEO) was investigated by radioiodine labeling of proteins using the iodine monochloride method. The results confirm that PMMA-g-SPEO can absorb a high level of albumin and resist the fibrinogen adsorption dramatically. The surface for attracting and reversibly binding albumin, which was proved to suppress the platelet adhesion and prolong the clotting time, has been developed on the composite surface structure of srearyl group and PEO.
    Studies on New Polymeric Solid Electrolytes Based on Urea and Thiocyanate
    WANG Zhi-Yin, HE Yun-Hua
    2002, 23(12):  2375-2377. 
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    The new polymeric solid electrolytes (PSE) based on urea(carbamide) and NH4SCN(KSCN) were synthesized. Their ionic conductivity is higher than 1.20×10-2 S/cm(2.65×10-3 S/cm) at room temperature. The main factors influencing the ionic conductivity were analyzed. The conductivity mechanism of PSE were disscused. The results show that the PSE are amorphous solid solution and the main conductance is NH4SCN(KSCN), which can ionize and conduct in the PSE, and the conductivity of PSE obeyed the VTF equation in the temperature range from 20 to 85 ℃.
    Influence of Heating and Freezing on the Hydrodynamic Properties of Ethyl Cellulose Dilute Solution
    LI Li, YANG Hu, CHENG Rong-Shi, WANG Zhi-Liu
    2002, 23(12):  2378-2381. 
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    A closed viscometer was designed for viscosity measurement of volatile solvent-based solutions. The influence of freezing-thawing and heating on the hydrodynamic properties of EC molecules was studied by viscometry and size exclusion chromatographic (SEC) analysis. The change of molecular structure and conformation of EC molecules in solution after treatments is discussed. Freezing-thawing treatment reduces the viscosity of EC dilute solutions. However, it doesn't make any significant change of the SEC retention volume of EC sample in THFsolvent. This suggests that the apparent hydrodynamic volume of EC molecules slightly decrease. Heating treatment reduces the apparent hydrodynamic volume of EC molecules more evidently. The viscosity of EC solution decreases obviously after heating treatment.
    Synthesis and Characterization of Poly(phthalazinone ehter sulfone ketone)s Containing Sodium Sulfonate Groups
    ZHANG Shou-Hai, YANG Da-Ling, JIAN Xi-Gao
    2002, 23(12):  2382-2385. 
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    4, 4'-Dichlorodiphenylsulfone(DCDPS) was sulfonated in fuming sulfuric acid. Poly(phthalazinone ether sulfone ketone)s were synthesized from 4-(4-hydroxyphenyl)-1-phthalazinone(DHPZ), 4,4'-dichlorodiphenylsulfone, sulfonated 4,4'-dichlorodiphenylsulfone(SDCDPS) and 4,4'-diflorodiphenylketone(DFDPK) in the presence of potassium carbonate in sulfolane. High molecular weight polymers with different degrees of sulfonation were obtained with intrinsic viscosities between 0.86 and 1.21 dL/g. The structure of sulfonated 4,4-dichlorodiphenylsulfone was confirmed by FTIR and 1H NMR. Polymers containing sodium sulfonate groups were characterized with IR and 1H NMR. The solubilities of the polymers were studied.
    Static and Dynamic Elasticities of PMMA Monolayers
    FANG Kun, ZOU Gang, HE Ping-sheng 
    2002, 23(12):  2386-2389. 
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    Based on measuring and analyzing the π-A isotherms and their differentiate curves for monolayers of polymethyl methacrylate(PMMA) with different molecular weights, the formation and the effect of molecular weight on the phase transition of PMMA monolayers were discussed in detail. The dynamic elasticity of each monolayer was determined by barrier oscillation method and compared with its static elasticity. It is showed that the interactions such as skew and twist of the macromolecular chains have a great effect on the formation and the static and dynamic behavior of PMMA monolayer. Both of the static and dynamic elasticities are biphasic and the former is much smaller than the latter in general. With increasing molecular weight, the condensability and stability become more obvious and the static and dynamic elasticities are larger.
    Fabrication of Patterned Polymer Resists for Ion Etching by Using Dewetting
    LU Guang, CAO Zhao-Liang, LU Zhen-Wu, LI Wei, YAO Ji-Min, ZHANG Gang, YANG Bai, SHEN Jia-Cong
    2002, 23(12):  2390-2392. 
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    A novel method using a combination of microcontact printing(μCP) technique, surface-directed condensation and surface- directed dewetting has been developed to fabricate patterned polymer films on gold substrates. These patterned polymer films can serve as resists in the argon ion etching effectively to transfer patterns into the underlying gold substrates. This method is flexible in controlling the shape and feature size of the patterns in the polymer resists by simply adjusting the concentration of polymer solution, and especially it also provides a route to sub-micrometer sized features by using an original template with micrometer sized features.
    Synthesis Studies on Blood Compatible Materials(Ⅶ)──A Novel Kind of Platelet Adhesion Resistant Polymers
    ZHOU Jing, SHEN Jian, LIN Si-Cong
    2002, 23(12):  2393-2395. 
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    According to the hypothesis of "Maintaining normal configuration", the polymers with the structure of sulfo-ammonium inner salt would be nonthrombogenic. In this paper, a series of polymers of 3-N,N-dimethyl-3-N-methacryloyloxyethyl ammonium propanesulfonate(DMAPS) and its copolymers with polyethyleneglycol monomethylether methacrylate were prepared by using different concentrations of monomers and crosslinking agent. Their blood compatibilities were evaluated by platelet adhesion method. The results show that PDMAPS is of excellent platelet adhesion resistance.
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