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Table of Content

    10 August 2005, Volume 26 Issue 8
    Articles
    Preparation and Characterization of Nickel Hydroxide Nanorods Using Hydrothermal Synthesis Method
    TIAN Zhou-Ling, JIAO Qing-Ze, ZHAO Yun
    2005, 26(8):  1387-1390. 
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    Nickel hydroxide nanorods were prepared by using hydrothermal synthesis method. The structures of Ni(OH)2 were characterized by X-ray diffractometer. The morphologies were observed by using TEM. The influences of hydrothermal reaction temperature and pH values on the morphologies and structure of the products were investigated. It was found that the best conditions for preparing nickel hydroxide nanorods were the reaction temperature in the range 180~200 ℃ and the pH value between 9 and 10.
    Synthesis of Amphiphilic Dimers of Gd(Ⅲ) Complexes and Their Liver-selective Contrast Enhancement in MRI
    ZHOU Jin-Lan, WAN Fu-Xian, YU Kai-Chao, DING Shang-Wu
    2005, 26(8):  1391-1394. 
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    Benzyl ester of L-lysine was bis-acylated with diethylenetriaminepentaacetic monoanhydride(DTPA-MA) and ethylenediaminetetraacetic monoanhydride(EDTA-MA) respectively to produce two dimeric ligands. The reactions of these two ligands with GdCl3·6H2O yield amphiphilic bi-nuclear Gd(Ⅲ) complexes. These new ligands and their respective Gd(Ⅲ) complexes were characterized by IR, 1HNMR and elemental analysis. The dimeric complexes show higher relaxivities as compared to that of Complex Gd-DTPA which is widely used in clinic diagnoses. The Gd(Ⅲ) complex with bis-diethylenetriaminepentaacetate of benzyl ester of lysine(Gd2·3a) exhibits no obvious toxicity and offers a higher MRI signal enhancement as well as longer retention time in the t1-weighted imaging of Wistar rat liver tissue compared to complex Gd-DTPA.
    Solid State Synthesis, Crystal Structure and Reflectance Spectra of K2Sn2Se4
    ZHANG Li-Dan, WEI Yong-Ge, FENG Xiu-Ling, GUO Hong-You
    2005, 26(8):  1395-1398. 
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    A novel ternary met al selenide bipotassium seleno-stannates(K2Sn2Se4) was synthesized by employing the molten-salt reaction of reactants at 550 ℃ for 7 days. The crystal crystallized in the space group I4cm with unit cell parameters a=0.815 24(12) nm, b=0.815 24(12) nm, c=0.671 52(13) nm. K2Sn2Se4 contains one-dimensional covelent chains 1[Sn2Se4] 2-anions along c-axis direction and separated by K cations. A reflectance spectroscopy study reveals the nature of semiconductor with an energy gap of 1.7 eV.
    Synthesis, Characterization and Crystal Structures of (Z)-1-[2-(Triphenylstannyl)vinyl]-1-indanol, Its Ester and Phenylhalostannyl Derivatives
    WU Jun-Zheng, WANG Ke-Liang, KANG Wan-Li, ZHU Dong-Sheng
    2005, 26(8):  1399-1404. 
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    (Z)-1-[2-(Triphenylstannyl)vinyl]-1-indanol 1 was synthesized by the additive reaction of 1-ethynylindanol with triphenyltin hydride. Compound 1 was esterified by phthalic anhydride to yield monoester derivative 2. Compounds 3 and 4 were prepared by the reaction of the monoester 2 with dibutyltin oxide and triphenyltin hydroxide, respectively. The phenyl groups in compound 1 were substituted by ICl, Br2 or I2 to yield mono-and dihalide derivatives(5-10). Compounds 1-10 were characterized by elemental analysis, 1HNMR and FT-IR spectroscopy. The crystal and molecular structures of compounds 1 and 6 were determined by single crystal X-ray diffraction analysis. The Sn atom in compound 1 exhibits a distorted trigonal bipyramidal structure due to a weak intramolecular interaction between Sn and the hydroxyl O atoms [0.277 8(8) nm], while the Sn atom in compound 6 adopts a trigonal bipyramidal geometry with a significant Sn1←O interaction [0.236 4(2) nm]. The Lewis acidities of the Sn atoms are in the following order: PhSnX2L>Ph2SnXL>Ph3SnL.
    Effect of Organic Molecule CTAB on Morphologies of Silver Nanoparticles
    WU Qing-Song, ZHAO Yan, ZHANG Cai-Bei
    2005, 26(8):  1405-1409. 
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    We reported on the dramatic chemical reshaping of silver nanoparticles upon exposure to cetylrimethylammonium bromide(CTAB) in aqueous solutions. In the presence of concentrated CTAB, the triangular silver nanoplates were observed to undergo a morphological change from truncated triangular, elliptic nanoplates to circular nanoplates. When dilute CTAB was employed, the triangular silver nanoplates were transformed into spindle silver nanoplates. Such transfigurations of silver nanoparticles were related to the concentration of bromide ions and organic groups of CTAB in the solutions. By changing the shape of silver nanopartilces their corresponding optical properties were tuned accordingly.
    A Computational Analysis Method of HPLC-DAD for Determining the Active Components of Natural Medicine
    ZHAO Xiao-Ping, CHEN Min-Jun, CHENG Yi-Yu
    2005, 26(8):  1410-1414. 
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    Window factor analysis(WFA) is an important method used to resolve the overlapping chromatographic peaks by processing HPLC-DAD data. The selection of window is one of the key factors to affect the accuracy of WFA. In this paper, the results obtained by WFA are used as the initial estimation, and then the estimated value is adaptively optimized by an alternative iteration procedure. In this way, a method named iterative fitting windows factor analysis(IFWFA) is proposed. It can correctly select the window for using WFA. Coupled with HPLC-DAD, the proposed method was used to determine tanshinone Ⅰ, cryptotanshinone and tanshinone ⅡA of Salvia miltiorrhiza, and the results show that their recoveries are 94.16%, 91.57% and 104.48%, respectively. Computer simulation and sample analysis experiments both demonstrate that the method is effective for improvement of analytical accuracy.
    Application of p-Nitrobenzene Azophenol Derivatives to Anion Recognition
    WU Fang-Ying, HU Mei-Hua, TAN Xiao-Fang, ZHAO Yong-Qiang, JI Zhao-Jun, LI Li
    2005, 26(8):  1415-1418. 
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    Compounds based on p-nitrobenzene azophenol were designed and synthesized. The properties of absorption spectra and association constants of complexes between hosts and anions were investigated and compare. The results indicated that the three compounds, 1-naphthol-4-azo-4'-nitrobenzene,8-hydroxyl-quinoline-5-azo-4'-nitrobenzene and 1-phenol-4-azo-4'-nitrobenzene, could act as efficient chromogenic reagents for the anion sensing. Upon addition of various anions, the spectral profile and color of the solution of hosts changed significantly. The affinity of hosts for anions was measured by UV-Vis spectroscopic titration experiments. For the same host, the association constants followed the order of AcO->F->H2PO--4Cl-, which was in agreement with the basicity order of anions. And for the same anions such as AcO-, the association constants followed the order of 3(α-naphthol)>2(8-hydroxyl-quinoline)>1(phenol), which is attributed to electronic withdrawing effect of substituents and the conjugated system of host compounds.
    Fabrication and Applications of PMMA Electrophoresis Chips Connected to Fused-silica Capillaries
    LIU Jun-Shan, GUO Huai-Zhong, WANG Li-Ding, CHEN Rong, WANG Song, SUN Yu-Qing, LUO Yi
    2005, 26(8):  1419-1423. 
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    To connect a capillary with an electrophoresis chip, a dead volume was usually created due to a hole with a conical-shaped bottom formed by drilling into the edge of the chip after the capillary was inserted into the hole. The effects of the dead volume on the electrophoretic separation were simulated and evaluated by using a simulation software. A novel connecting PMMA electrophoresis chips to capillaries with the minimal dead volume was presented. A hole was drilled into the edge of the chip by using a 500 μm standard drill bit, then a home-made flattened drill bit was used to flatten the conical area, so a flattened-bottom hole was created, and a 375 μm-o.d. fused-silica capillary was inserted into the hole and fixed by using epoxy, which decreases the dead volume from 3.9 to 0.1 nL. The detecting point of the UV-absorption detection was put on the fused-silica capillary, so the electrophoresis on the PMMA chip could be directly detected by an UV-absorption detector. The electrophoretic analysis of vitamin B2 was performed on the chip, and the number of theoretical plates was 73 000/m; the electrophoretic separation of three components of sulfamethoxazole, sulfadiazine and trimethoprim tablet was also preformed, resolutions among these three components were 4.5 and 1.9, the relative standard deviations for migration time were 1.0%, 1.4% and 1.0%, and relative standard deviations for peak height were 4.1%, 3.0%, 4.1%, respectively(n=5).
    Analyses of Seven Kinds of Phenolic Acids in Wine by HPLC with Electrochemical Detection
    CAO Wei, SUO Zhi-Rong, SONG Ji-Rong, ZHENG Jian-Bin
    2005, 26(8):  1424-1427. 
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    A rapid, sensitive and accurate reverse phase HPLC-ECD method for simultaneous determination of seven kinds of bioactive phenolic acids(gallic acid, protocatechuic acid, syringic acid, p-coumaric acid, caffeic acid, chlorogenic acid, ferulic acid) in five different types of wine was developed. The separation was performed on Hypersil ODS column(250 mm×4.0 mm, 5.0 μm) by gradient elution. The mobile phase consisted of CH-3OH-4%HAc. The flow rate was 0.8 mL/min. The working potential was 0.7 V and column temperature was 30 ℃. The experimental results showed that the seven kinds of phenolic acids were separated satisfactorily. The detection limit of phenolic acids with ECD was 4-600 times greater than those obtained with UV detection.
    Determination of Poly-L-lysine with a Water-soluble Fluorescence Polymer
    CHEN Yan-Guo, HE Zhi-Ke
    2005, 26(8):  1428-1431. 
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    A water-soluble fluorescence polymer poly[5-methoxy-2-(3-sulfopropoxy)-1,4-phenylene-vinylene](MPS-PPV) was synthesized and characterized by elemental analysis, infrared absorption spectrun and the transmission electron microscope micrograph. The fluorescence of MPS-PPV could be quenched by poly-L-lysine(PLL), a new food preservative. So a rapid and sensitive method for the determination of PLL was set up, the linear range and detection limit were 3.6×10-92.5×10-8 mol/L and 5.0×10-10 mol/L respectively. The fluorescence quenching mechanism of PLL to MPS-PPV was also discussed, which was caused by the strong electrostatic interaction between cationic PLL and anion conjugated polymer MPS-PPV.
    DNA Electrochemical Biosensor Based on Functional Gold Nanoparticles-amplification
    LI Jin-Hua, HU Jing-Bo, DING Xiao-Qin, LI Qi-Long
    2005, 26(8):  1432-1436. 
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    Ferrocene(Fc)-capped gold nanoparticle/streptavidin conjugates were attached onto the electrodes covered with either biotinylated or sandwich oligodeoxynucleotides(ODNs) duplexes. The binding events were monitored by electrochemical signal of ferrocene. The signal differences permitted to distinguish the match of two perfectly complementary DNA strands from the near-perfect match where just one base pair was mutant. The effects of the DNA probe and target strand lengths on the voltammetric behavior of the Fc groups were studied. It was found that shorter duplexes would lead to a more reversible voltammetric wave and a higher detection level. For the analysis of 30-mer biotinylated target DNA, a concentration level as low as 2.5×10-4 nmol/L could be detected while for 39-mer target of sandwich duplexes, the limit of detection was 2.0×10-3 nmol/L. The capabilities of the method for trace analysis of DNA can be attributed to the enhanced voltammetric detection by the large number of Fc moieties present in each conjugate.
    Micellar Electrokinetic Capillary Chromatography Study of Adenine and Purine of Anti-cancer Medicine
    ZHANG Lan, LI Rui-Bao, TONG Ping, CHEN Guo-Nan
    2005, 26(8):  1437-1439. 
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    The adenine, 8-hypoxanthine, 6-thioguanine and 8-azaguanine were separated and determined with the method of micellar electrokinetic capillary chromatography. The optimal conditions of electrophoresis were studied. At 25 ℃ and 20 kV applied voltage, the four components were baseline separated within 16 min in 25 mmol/L phosphate-borate buffer(pH=7.0) including 30 mmol/L SDS at the detection wavelength of 210 nm. The peek area versus concentration was linear over the concentration range of (12-200)×10-6 mol/L for 8-hypoxanthine and 8-azaguanine, and (6.5-100)×10-6 mol/L for adenine and 6-thioguanine. The detection limits of all analytes mentioned above attained to 10-6 mol/L grade. And the correlationg coefficients of four analytes were over 0.998 5. In the real sample of the mean absolute recoveries of 8-hypoxanthine, adenine, 6-thioguanine and 8-azaguanine were 97.2%-102.1%, and the relative standard deviations for the four components were less than 3.41%(n=5). The method is rapid, simple with a good solution for the analysis of 8-hypoxanthine, adenine, 6-thioguanine and 8-azaguanine, and satisfactory results were obtained.
    Simultaneous Determination of Trance Niobium and Tantalum via Kalman Filter-flow Injection Chemiluminescence
    LIU Ming-Yang, LI Jun-Feng, WANG Hong-Xia, WANG Hong-Yan
    2005, 26(8):  1440-1442. 
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    A fast and highly sensitive Kalman Filter analysis with flow injection-chemiluminescence(FI-CL) method for simultaneously determining the trace amounts of niobium and tantalum without separating them were developed in this paper. After depositing-separation of most interference ions, 1% EDTA as the mask reagent was used to dispel the effect of residual interference elements. The mixed chemiluminescence kinetic curve of Nb and Ta(Ⅴ) was analyzed by Kalman Filter in this method to realize the simultaneous determination of niobium and tantalum in the national standard samples.
    Synthesis of Chiral Stationary Phases via Bonding β-cyclodextrin with α-Schiff Base and Chromatographic Performance
    FANG Min, ZHOU Zhi-Ming, LUO Ai-Qin
    2005, 26(8):  1443-1445. 
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    Two chiral stationary phases(BCDs and YBCDs) were prepared by bonding β-cyclodextrin derivative with α-Schiff base group from β-cyclodextrin monoaldehyde to the sillica gel via 3-glyci-dyloxypropyltrimethoxysilane as a coupling agent. Using acetonitrile-TEAA as mobile phase, good enantiomeric resolutions were obtained for DL-aminoacide on BCDs and YBCDs, including Leucine, Threonine and Valine. It is also observed that the higher separation factor of threonine was at pH {7.11} for both of the column, and the optimal column temperatures of Leucine appeared at 30 ℃ or 40 ℃, respectively for YBCDs and BCDs.
    Effect of Bupleurun Chinese DC(BCDC) on the MDR Reversal of Hepatocellular Carcinoma and Related Mechanism
    GAI Xiao-Dong, ZENG Chang-Qian, HONG Min
    2005, 26(8):  1446-1450. 
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    The reversal effect and mechanisms of BCDC were evaluated by using Bel-7402 cell line with innate resistance in this study. The identification of new and less toxic reversal agent, BCDC, would open a new perspectives in cancer treatment. The results show that BCDC has an effect on MDR reversal of Bel-7402 cell line and a synergetic effect with VCR. The reversal mechanisms were due to suppress MDR1 transcription and P-gp expression, as a result, to leave TopoⅡα mRNA level, to increase intracellular VCR concentration of Bol-7402 cell, to enhance cell G2M phase arrest induced by VCR.
    Synthesis and Photochromic Properties of Oxazoly Substituted Fulgide
    LU Zhen, FENG Yu-Lin, CHEN Zhao-Bin, XIAO Jun-Ping, YAN Wen-Peng, FAN Mei-Gong
    2005, 26(8):  1451-1454. 
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    4-[5-Methyl-2-(p-methyloxyphenyl)-4-acetyloxazoly]ethylidene(isoproylidene) succinic anhydride was synthesized by Stobbe condensations of 4-acetyl-5-methyl-2-(p-methyloxyphenyl) oxazole with diethyl 2-isopropylidene succinate in toluene, in the presence of sodium hydride, followed by cyclization of diacid by treatment with acetyl chloride. The photochromic properties of the fulgide in various solvents were studied. The solvent effects on the absorption spectra were also investigated. The analysis results obtained by steady state kinetics show that the photodecoloration of the colored form followed the first-order kinetics. The photocoloration reactions were more complicated and did not fit simple kinetics.
    Crystal Structure for Cytotoxic Diterpenoids Wangzaozin A
    DING Lan, YU Kai-Bei, LIU Guo-An
    2005, 26(8):  1455-1458. 
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    The crystal structure of Wangzaozin A was elucidated on the basis of the single-crystal X-ray diffraction analysis. The {X-ray} crystal structure revealed that there were two molecules with a little difference in the bond lengths and bond angles data in least asymmetry unit, and three six-membered rings were in a chair-like conformation, five-membered rings adopted a twist envelope-like conformation in the compound, respectively. The crystal of the compound was in orthorhombic crystal system, space group P2-12-12-1 with accurate lattice constants as follows a=0.664 85(8) nm, b={2.579 6(4) nm}, c={1.047 3(2) nm}, Z=4. The molecules formed extensive networks through the intra-molecular hydrogen bonds O3-H30…O2, O3'-H30'…O2' and intermolecular hydrogen bonds O1-H10…O3, {O1'-H10'…O3'}, O2-H20…O4', O2'-H20'…O4, and arranged along c axis in the crystal. The compound was found to exhibit a significant cytotoxicity against human tumor Bel-7402 and {HO-8910} cells with (5.32±0.79) and (4.10±1.00) μmol/L in SRB assay, respectively.
    Synthesis and Herbicidal Activity of New Sulfonylurea Derivatives
    LI Peng-Fei, MA Ning, WANG Bao-Lei, LI Zheng-Ming, WANG Su-Hua, LI Yong-Hong
    2005, 26(8):  1459-1462. 
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    In order to search for more environmental-benign sulfonylurea herbicides and study their structure-activity relationship, on the basis of a new sulfonylurea herbicide NK94827 {N-[(4'-methyl)pyrimidin-2'-yl]-2-methoxycarbonyl phenylsulfonylurea}, 18 novel sulfonylurea compounds modified at benzoic acid ester were synthesized. The structures of the target compounds were confirmed by 1HNMR and elemental analysis. Preliminary herbicidal activity of these new sulfonylurea compounds was determined by rape disc assay and pot bioassay experiments. The results indicate that some compounds have good a herbicidal activity, and large lipophilic groups in ester moiety are unfavorable for the activity.
    Synthesis of (R)-2-Methyl-7-octynoic Acid
    CHEN Hong-Liang, FENG Ya-Qing, XU Zheng-Shuang, LIU Xin-Gang
    2005, 26(8):  1463-1466. 
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    The marine peptides have been a fertile source for new bioactive molecules, and many possess potent activity, across a broad spectrum of targets. Their diversity in both biological activity and in chemical complexity has made these secondary metabolites being the focus of much work in recent years. As a fragment, (R)-2-methyloctanoic acid-7-yne was always found in those nature materials. In this article, (R)-2-methyl-7-octynoic acid was synthesized with pentane-1,5-diol as the start material. Stereogenic carbon(C-2) was obtained through alkylation induced with Evans' chiral auxiliary, and alkyne 13 was got by use of Ohira-Bestmann reagent. Through 13-step reactions the target molecule was prepared with over yield of 17.1%, and e.e. beyond 99%.
    Preparation and Characterization of Biscalix [4] arene with Alkyne-containing Spacer
    WANG Wei, GONG Shu-Ling, MENG Ling-Zhi, CHEN Yuan-Yin
    2005, 26(8):  1467-1470. 
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    Single 2-butyne-bridged and double 2-butyne-bridged biscalix[4]arenes were prepared directly by the reaction of p-tert-butylcalix[4]arene with 1,4-dichloro-2-butyne using K2CO3- as a base in acetonitrile. It was found that the double 2-butyne-bridged biscalix[4]arene was formed via 2-butyne-single bridged biscalix[4]arene. Their structures were characterized by 1HNMR, 13CNMR and ESI-MS. They exhibited different complexion ability towards DMF and H2O molecule.
    Synthesis and Negative Photochromic Properties of Photochromic Spiropyrans Compounds Supported by Polyethylene Glycol
    ZOU Wu-Xin, TAN Ting-Feng, LI Xu, Meng Ji-Ben
    2005, 26(8):  1471-1473. 
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    Spirobenzopyrans with carboxylic group were successfully supported by polyethylene glycols in the presence of DCC from the derivatives of indolinospirobenzopyrans and polyethylene glycols. Hydroxyl of polyethylene glycols and carboxylic group in photochromic spirobenzopyrans act as the active groups. Spirobenzopyrans with a good water-solubility were synthesized by introducing hydrophilic groups. Their photochromic properties in solution were investigated by UV-Vis spectroscopy. It is shown that the new compounds had good photochromic properties in ethanol, acetone and ethyl acetate, especially good negative photochromic properties in water under irradiation at 365 nm. The method has advantage of cheap reagents, simple workup procedure. It is of great value for evolution in research studies of new photochromic materials.
    Synthesis of Chlorin-enediyne Dyads Fused with Heterocyclic Ring by Palladium-catalyzed Coupling Reaction
    YIN Jun-Gang, WANG Jin-Jun, SHIM Young-Key
    2005, 26(8):  1474-1476. 
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    The terminal alkyne was constructed in chlorin chromophore by Grignard reaction and oxidation to give chlorin 2 and 3, respectively. After deprotection the diketo chlorin 4 was obtained which was readily converted to the Zn-complex 5. Chlorin-enediyne dyads 6 fused with heterocyclic ring was synthesized by a palladium-catalyzed coupling reaction with 2-(1-hexynyl)-3-chlorothiophene.
    One-step Synthesis of Thalidomide and Its Important Derivatives
    YUAN Xiu-Hua, GUO Hai-Quan, QIU Xue-Peng, KANG Chuan-Qing, LIU Xu-Dong, GAO Lian-Xun
    2005, 26(8):  1477-1479. 
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    Thalidomide and its derivatives have great potentials in immune therapy. This research note presented that heating the mixture of phthalic anhydride or its chloro or nitro substituted derivatives and L-glutamine in vacuum afforded thalidomide 1 and its corresponding derivatives 2—5 directly in yields 24%-47%. Among them, compound 4 is the material in the synthesis of 3-amino and 3-amino-3'-fluoro substituted thalidomide. Compared with traditional methods, this method is more direct and convenient.
    A Mass Spectroscopic Investigation to Redox Mechanism of p-Nitrotoluene in Sodium Polysulfide Solution
    GAO Po, YUE Zheng-Yu, CHEN Nian-Gai, TANG Hui-Tong
    2005, 26(8):  1480-1483. 
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    The reaction of p-nitrotoluene in the ethanol/sodium polysulfide solution resulting in {p-aminobenzaldehyde} has been applied to industry. However the reaction mechanism is not accepted commonly since the accordant conclusion among the proposed mechanisms was not reached due to lacking of the verification mutually. In this paper, we monitored the reaction intermediates and their transition regularity by high resolution mass spectra. The results show that the condensation compounds emerged during the reaction at 80 ℃ with the reaction starting up to 120 min, strongly supporting the condensation and oxidation mechanisms proposed by Shchukina and Chen, respectively, that is, p-aminobenzaldehyde is derived from the hydrolysis of poly Schiff base. Meanwhile, we propose the possibility of formation process of poly Schiff base, which is different from that reported in literatures.
    Synthesis and Structure Evolution of LiNi1-xAlxO2(x=0—0.6)
    LIU Wei, GONG Jie, YANG Jing-Hai, ZONG Zhan-Guo, CHEN Gang
    2005, 26(8):  1484-1487. 
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    LiNi1-xAlxO2 is one of new cathode materials for lithium batteries, which was a solid solution of LiNiO-2 and α-LiAlO2. However, it is difficult to synthesize the solid solution with a high aluminum solid solubility because it is easy to decompose due to its negative synthesis enthalpy. A new synthesis method was obtained by studying the preparation conditions of LiNiO-2 and α-LiAlO2, then LiNi1-xAlxO2(x=0—0.6) was synthesized successfully. The samples of LiNi1-xAlxO2(x=0—0.6)were studied by XRD and XPS, the results show that all samples have a single α-NaFeO2 structure and LiNi1-xAlxO2 solid solutions were synthesized. With the increasing of aluminum solid solubility x, not only Ni(Al)O binding energy increased, but also lattice constant decreased and the ratio of c/a increased. As a result, the bedded structure was more obvious and the stability was enhanced.
    Effect of Gallium Doping on the Layered LiCo0.3-xGaxNi0.7O2 Cathode Materials for Lithium Secondary Batteries
    TONG Dong-Ge, LAI Qiong-Yu, JI Xiao-Yang
    2005, 26(8):  1488-1491. 
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    Gallium-doped layered LiCo0.3-xGaxNi0.7O2 materials were synthesized by a sol-gel method. Single phase of LiCo0.3-xGaxNi0.7O2 could be prepared in 0≤x≤0.5 region. The samples were characterized by means of XRD, particle size, BET and charge/discharge test. The discharge capacity of {LiCo0.3-xGaxNi0.7O2} increased with the increase of gallium contents. The initial discharge capacity of {LiCo0.25Ga0.05Ni0.7O2} was 177.5 mA·h/g between 2.8 and 4.3 V at 0.2 C and had no capacity loss after 25 cycles. Furthermore, the discharge capacity of LiCo0.25Ga0.05Ni0.7O2 was completely recovered after cycling at high discharge-rates. The discharge capacity increased with the upper cut-off voltage limit with a good cycle-ability regardless of the upper cut-off voltage limit. Meanwhile, only one phase reaction took place during the electrochemical oxidation and reduction process, indicating no structure degradation.
    Preparation and Characterization of AlPxO Catalysts and Their Catalytic Properties for the Vapour-phase O-Methylation of Catechol
    LIU Gang, LI Xue-Mei, ZHU Xiao-Mei, JIA Ming-Jun, WU Shu-Jie, ZHANG Wen-Xiang, JIANG Da-Zhen
    2005, 26(8):  1492-1496. 
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    AlPxO(x=0, 0.33, 0.5, 1.0, 1.5, 2.0) catalysts were prepared via precipitation method and characterized by means of XRD, FTIR, solid-state MAS NMR, N2 adsorption, NH-3-TPD and CO-2-TPD techniques. The morphology of the catalysts changes from amorphism to crystalline with the increase of n(P)/n(Al). Both the acidic and basic amounts on the catalysts surface increase first with the increase of P contents [n(P)/n(Al)≤0.5], and then decrease dramatically with further increasing P contents. Meanwhile, vapor-phase O-methylation of catechol with methanol was investigated over various AlPxO catalysts. Among them, AlP1.0O sample exhibits a good {catalytic} activity and selectivity to guaiacol, which resulted in the highest yield of guaiacol. This may mainly be attributed to the presence of suitable amounts of weak acid and base sites on the surface of the catalyst.
    Polyhedral Molecular Orbital Theory to Niobium Clusters and Met al Complex
    WANG Xian, LIN Meng-Hai, TAN Kai, WANG Fan, ZHANG Qian-Er
    2005, 26(8):  1497-1501. 
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    The polyhedral molecular orbital method was applied to several niobium clusters, and a model of standard trigonometric integral was used in order to simplify the calculation of group overlap integrals. Furthermore, the results were checked by the density functional theory. The comparisons show that the polyhedral molecular orbital theory is a more efficient way for studying the bond characters of polyhedral compounds, especially transition met al clusters, than the traditional calculation methods. For example, this method predicts that the sizes of niobium clusters possess low magnetic moments as ground states, and the electronic structures of Nb4 and [Nb6Cl 12]+4. Although the geometry structures of Nb5 and Nb6 are transformed resulting from the Jahn-Teller effects and electronic-correlated effects, the theoretical prediction also show the trend of transformation.
    Transesterification of Dimethyl Carbonate and Phenol Catalyzed by Zn-Al Hydrotalcite
    YU Qin-Qin, WANG Shu, BAI Rong-Xian, MEI Fu-Ming, LI Guang-Xing
    2005, 26(8):  1502-1506. 
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    The Zn-Al hydrotalcite prepared by co-precipitation method was used to catalyze the transesterification of phenol and dimethyl carbonate(DMC). The catalytic activity of Zn-Al hydrotalcite with different molar ratios of Zn to Al and their calcined products were tested. It is found that Zn-Al hydrotalcite has a high catalytic activity and selectivity in the reaction. Under the reaction conditions of n(Zn)/n(Al)=3, n(PhOH)/n(DMC)=2, mass fraction of catalyst =1.5%, t=150180 ℃ and t=12 h, the conversion of DMC reached 55.9%, yield of DPC and MPC was 25.3% and 27% respectively, the selectivity for the transesterificated products was 93.6%. When the hydrotalcite was calcined at 450 ℃ for 8 h, the catalytic activity of them decreased sharply and the XRD patterns indicated that the lamellar structure had already collapsed, which suggested that the specific structure of hydrotalcite is important to catalyze the transesterification. The structure and morphology of Zn-Al hydrotalcite was characterized by XRD and TEM, and the TG-DTA characterization indicated that the structure of Zn-Al hydrotalcite was stable in the range of reaction temperature. The structure and morphology of the catalyst were characterized by XRD, TG-DTA and TEM.
    Novel Cu-Ir Bimet allic Catalysts Supported on CeO-2 Modified SiO2-
    WANG Li-Nan, ZHANG Xiong-Wei, CHU Wei, YANG Wei-Shen, ZHANG Tao
    2005, 26(8):  1506-1506,1521. 
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    The novel Cu-Ir bimet allic catalysts with ceria modified silica supported were prepared via impregnation method for methanol decomposition. Cu-Ir/CeO2--SiO2- catalyst exhibited a higher catalytic activity and a better stability than Cu-Ir/SiO2- catalyst. After 10 h of reaction, the methanol conversion was still over 96% with ceria modified Cu-Ir/SiO2- catalyst, while that of Cu-Ir/SiO2- catalyst decreased to 39.1%. The catalyst samples were characterized by XPS, H2-TPR, XRD and BET techniques. The addition of ceria to silica supported Cu-Ir catalyst could improve the dispersion and restrain the sintering of the active component.
    Structure Exploration and Function Prediction of SARS Coronavirus E Protein
    SHAO Chen, HU Dong-Hua, SUN Hai-Zhu, YAN Li-Kai, SU Zhong-Min, WANG Rong-Shun, ZHU Wen-Sheng, GUO Jian-Hua, SHI Ning-Zhong, SUN Hui, LI Ze-Sheng, SUN Chia-Chung
    2005, 26(8):  1507-1511. 
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    SARS E protein has long been taken only as membrane component of coronavirus. However, the researches have revealed that E proteins play an important multifunctional role in coronavirus virion life cycle. This investigation aims at exploring the three-dimensional(3D) structure of SARS E protein, especially for the loop region of its functional potential. As a result, a possible active site is found to be a cleavage in the C terminal, which is made up of nine amino acids. Additionally, the electrostatic property was employed to conform the possible active site. Electrostatic potential analysis prove that the active site really possesses the largest electrostatic property among the whole molecule domain, accordingly it will have a larger charge deposition and therefore may have stronger capabilities of interaction with possible ligand as well as other protein. The simulation results are helpful to providing insights into understanding the functions of SARS E protein and establishing molecular models for screening anti-SARS drug design.
    Spectroscopic Investigation of New Room-temperature Molten Salt Based on LiTFSI with Acetamide
    CHEN Ren-Jie, WU Feng, LI Li
    2005, 26(8):  1512-1516. 
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    New room-temperature molten salt based on lithium bis(trifluoro methane sucfone) imide(LiTFSI) and acetamide with a proper molar ratio has an excellent thermal stability and electrochemical performance. The action mechanism was studied by FTIR spectroscopy, FT-Raman spectroscopy and quantum chemistry calculation with nonlocal DFT. The vibrational spectra and calculated results show that acetamide can coordinate with Li+ cation in LiTFSI through Li—O bonding, and electrovalent bonding of LiTFSI was destroyed. A big coordinate cation formed and its positive charge was shielded in acetamide molecule. Charges of TFSI-ion were partly off resulting in to shielding of charges in the whole molecule by the terminal CF3- group. The coulombic forces was very weakly between the cations and anions, and the coordination of LiO can also cause the breakage of hydrogen bonding between acetamide molecules, resulting in the formation of this molten salt in the liquid state.
    A Theoretical Study of Interaction Between Dinitrogen and Single Transition-met al Centers Mo, Fe and V
    JIN Xi, CAO Ze-Xing, ZHANG Qian-Er
    2005, 26(8):  1517-1521. 
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    Complexes of the transition met al-containing model compounds with dinitrogen (N2)M(NH2)3(NH3) and (N2)M(SH)3(NH3)(-OCH2COO-) [MMo,V, Fe] were studied by the density functional theory. The relative energetics of the reduction of N2 to ammonia by the proton-electron transfer to the dinitrogen derivative was predicted. The calculated results show that there is a strong interaction between the Mo center and dinitrogen and the V…NN interaction is relatively weak, whereas the Fe center cannot bind N2. The homocitrate ring opening in the simplified Mo-containing fragment in the FeMoco was predicted to be manipulable by controlling the spin multiplicity and oxidation state of the transition met al complex. The present results from both models indicate that the Mo is the most efficient active site for the dinitrogen binding and reduction among the single transition-met al centers Mo, V and Fe.
    Prediction of Antifungal Activity with Support Vector Machine
    LI Ze-Rong, CHEN Shi-Wei, TAN Ning-Xin, CHEN Yu-Zong, LI Xiang-Yuan
    2005, 26(8):  1522-1526. 
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    A set of 67 molecular descriptors, including electronic, topological, geometric descriptors and molecular shape indices, were calculated and used to predict the antifungal activity for 94 organic compounds by means of support vector machine method. The model was validated in two ways: leave-one-out and 5-fold cross-validation. In the 5-fold cross-validation, the compounds were divided into several clusters based on their similarities. The training sets were sorted by selecting molecules randomly from each cluster, the rest of the molecules being the test set. It was shown that two validation methods give similar results and our model has a good prediction ability, and about 84% of the compounds can be correctly classified.
    Photochemical Reaction of Fe(Ⅲ)-organic Acid Complex in Seawater
    YANG Gui-Peng, ZHAO Run-De
    2005, 26(8):  1527-1531. 
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    The study on the photochemical reaction of Fe(Ⅲ)-organic acid complex in seawater was carried out by exposing the reaction solution to a high pressure lamp under different experimental conditions. The photo-reduction rate constants of Fe(Ⅲ) were affected by various factors including organic acid(OA) concentration, pH, light intensity and temperature. When the molar ratio of organic acid to Fe(Ⅲ) was above 2, the photo-reduction reaction of Fe(Ⅲ) exhibited a first-order reaction kinetic pattern at the initial stage, and remained nearly stable after 100 min, which could be described by the equation: [Fe(Ⅱ)]tkOA[OA][Fe(Ⅲ)]ini×[1-exp-(kOA[OA]+kox)t]/(kOA[OA]+kox).At near pH7, the activity of organic acids examined declined by the sequence below: tartaric acid>adipic acid>succinic acid>malic acid>malonic acid. Increase of irradiation intensity and decrease of pH value could enhance the photo-reduction rate of Fe(Ⅲ). On the contrary, when the temperature varied, the photo-reduction rate remained unchanged, which proved that the process of photo-reduction of Fe(Ⅲ) was a ligand-to-met al charge transfer process.
    Studies on Surface-enhanced Raman Spectroscopy on Bare Zn Electrode
    GU Ren-Ao, SHEN Xiao-Ying, LIU Guo-Kun, TIAN Zhong-Qun
    2005, 26(8):  1532-1536. 
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    Various roughening procedures for the bare Zn electrode such as chemical etching, electrochemical deposition and the electrochemical oxidation-reduction method were tried to obtain surface-enhanced Raman spectroscopy(SERS) from it and electrochemical oxidation-reduction method was proved effectively. Two electrochemical oxidation-reduction methods were described. One is linear sweep oxidation-reduction cycles(ORC) and the other is a double-step ORC. By using confocal Raman microscopy, surface enhanced Raman spectra of pyridine adsorbed on the bare roughened Zn electrodes were observed for the first time, when reduction potential was controlled at -1.6 V and oxidation potential at -0.7 V.
    Fluorescence Spectroscopic Study on 2-(2-Pyridyl)imidazole at Different pH Values
    ZHANG Heng-Jun, XU Hong-Bin, ZHAO Ya-Hui, YUE Shu-Mei, LIU Si-Dong, CUI Xiu-Jun, MA Jian-Fang, SU Zhong-Min
    2005, 26(8):  1537-1540. 
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    2-(2-Pyridyl)imidazole(2PI) was synthesized and the photophysical behavior in aqueous solution was studied in a wide range of acidity by steady-state fluorescence spectroscopy measurement. It was found that the intramolecular photoinduced electron transfer(PET) took place in the solution and the process strongly depended on the acidity of the solution and was affected by the protonation of nitrogen atoms.
    Synthesis and Characterization of Macroinitiator Polystyrene and Block Copolymerization in the Presence of Sodium Nitrite and Iron(Ⅱ) Sulfate
    XU Miao-Qing, HUANG Jian-Ying, YAN Ming-Fa, LIN Ming-Hua, LIN Qiang, CHEN Yi-Hong, ZOU You-Si
    2005, 26(8):  1541-1543. 
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    In the presence of sodium nitrite and iron(Ⅱ) sulfate the controlled polystyrenes with different molecular weight weres synthesized. The polystyrene macroinitiator could initiate the polymerization of methyl methacrylate(MMA), methyl acrylate(MA), ethyl acrylate(EA), and styrene(St). All the polymerizations have the characters of the living polymerization that the molecular weight of the copolymer gradually increased with conversion and the polydispersity indexes are below 1.5. In addition, block copolymer's experimental molecular weight is similar to theoretical molecular weight. The basic mechanism for the control of radical polymerization is thus a nitroxide-mediated process, such as TEMPO, and the price was reduced greatly, which is of benefits to the industries application. The block copolymerization formation was confirmed by 1HNMR and GPC measurements.
    Synthesis of Amphiphilic Diblock Copolymer Poly(L-alanine)-b-poly(hydroxyethyl glutamine) and Its Self-assembly in Water
    LI Li-Ying, SUN Ping-Chuan, YAO Yang, CHEN Tie-Hong, LI Bao-Hui, JIN Qing-Hua, DING Da-Tong
    2005, 26(8):  1544-1547. 
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    Two kinds of amino acid N-carboxyanhydrides γ-benzyl-glutamate N-carboxyanhydride(GluB-NCA), and L-alanine N-carboxyanhydride(Ala-NCA) were synthesized according to phosgene method(Fuchs-Farthing method). Poly(L-alanine)-block-poly(γ-benzyl-glutamate)(PLA-b-PBLG) AB diblock copolypeptide was synthesized by ring opening polymerization of Ala-NCA and GluB-NCA, with triethylamine as the initiator. The poly(L-alanine)-b-poly(hydroxyethyl glutamine)(PLA-b-PHEGA) diblock copolypeptide was obtained by reacting the PLA-b-PBLG diblock copolypeptide with ethanolamine to improve the hydrophilicity of PBLG block. The structure of the product was characterized by means of FTIR and 1HNMR. The aggregation morphologies of the PLA-b-PHEGA diblock copolypeptide in aqueous solution were observed by TEM. It was found that the diblock copolypeptide could be self-assembled to form vesicles in water.
    Controllable Assembly of Colloid Particles on the Surface of Polyelectrolyte Multilayer Films
    QIN Sheng, CHEN Liu-Sheng, SHI Yi, JIN Xi-Gao
    2005, 26(8):  1548-1551. 
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    Colloidal adsorption onto certain substrates is of great interest in both basic colloidal chemistry and colloidal lithography with a larger surface area. We studied the assembly of sulfonated polystyrene particles that have anionic charges on the surfaces of the polyelectrolyte multilayer(PEM) films composed of poly(diallyldimethylammonium chloride)(PDDA) and poly(sodium 4-styrenesulfonate)(PSS). The monolayer assembly of the colloid particles without three-dimensional aggregation could be observed by atomic force microscope(AFM) and scanning electron microscope(SEM), and the number of colloids adsorbed per square micrometer was varied systematically from 2 to 7 by fine-tuning the fabrication and postfabrication of PEMs. Based on an electrostatic point of view, an approaching particle is attracted by the precursor film and repulsed by adsorbed particles, the balance between the attraction and repulsion is affected by alternation of surface property of PEMs. This method can provide a fabrication way of a wide range of dotted materials in which its feature size is the diameter of colloid particles.
    Effect of Transesterification on High-pressure Crystallization Behaviour of PET/PC Blend System
    LV Jun, WANG Xuan-Lun, HUANG Rui, LI Liang-Bin
    2005, 26(8):  1552-1555. 
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    Effect of transesterification on high-pressure crystallization behaviour of PET/PC blend system was investigated by torque rheometer, DSC, SEM and WAXD measurements. The crystallized samples of 20% PC in PET/PC blends mixed at 30 r/min and 523, 533 and 553 K for 15 min were obtained at 300 MPa and 613 K for 6 h with a self-made piston-cylinder high-pressure apparatus. SEM observation revealed that transesterification during mixing profited a quick thickening of extended-chain crystals and enhanced ester interchange at a high pressure. Wedge-shaped and bending extended-chain crystals found in these samples indicated that chain-sliding diffusion and transesterification contributed to the growth of such polyester crystal. With transesterification extent rising, the result of WAXD profile deconvolution and W-A/FT showed that the total crystallinity letted up, the mean crystallite size and micro-strain of PET increased and decreased respectively and crystallite distribution for PET widened correspondingly. The result obtained suggests that under certain conditions two procedures, i.e. crystallization-induced reaction and reaction-induced crystallization can concur for such copolymer wholly composed of crystallizable units.
    Local Conformations of Poly(vinyl methyl ether)
    ZENG Xi-Guo, CHEN Lin, YANG Xiao-Zhen
    2005, 26(8):  1556-1560. 
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    A full-relaxation optimization of molecular structure and the Dreiding Ⅱ force field are employed to obtain the geometry parameters and the conformational energies of meso and racemic dyad of poly(vinyl methyl ether)(PVME). It is found in this study that three different side-group orientations result in different energetic contour maps. A reasonable RIS model of PVME has thus been built up based on the statistical average of the energies from the three different orientation models. The characteristic ratio of PVME calculated was found to be agreement with the experiment result. Therefore, considering the orientation of side-group allows us to satisfactorily reproduce the experimental dimensions of random PVME chain.
    Nonlinear Optical Properties of Poly(p-phenylene vinylene) Derivative Modified by N+ Ion Implantation
    LI Bao-Ming, WU Hong-Cai, GAO Chao, SUN Jian-Ping
    2005, 26(8):  1561-1564. 
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    A soluble poly[2-methoxy-5-(3'-methyl)butoxy]-p-phenylene vinylene(MMB-PPV) was synthesized by dehydrochlorination reaction from p-methoxylphenol and isoamyl bromide as the raw materials and characterized by 1HNMR and FTIR. The MMB-PPV films were prepared and implanted by nitrogen ion(N+) with the dose ranging from 3.8×10{15} to 9.6×1016 ions/cm2 at an energy of 15 keV. UV-Vis spectra exhibited that the optical absorption in visible region was improved by ion implantation followed by a red shift of optical absorption threshold and the optical bandgap(E-g) between excited state and ground state was reduced from 2.12 eV to 1.81 eV with the increase of ion dose. The third-order nonlinear optical susceptibilities(χ(3)) were measured by degenerate four-wave mixing(DFWM) technique at 532 nm. Using the relative measurement method, the χ(3) value of pristine MMB-PPV film was 7.1×10-10 esu and became larger with the ion dose increasing and reached the maximum value of 9.3×10-9 esu at an ion dose of 3.8×1016 ions/cm2 which was almost one order of magnitude higher than that of the pristine MMB-PPV film. With the continuous increase of ion dose the χ(3) value decreased gradually, and when the ion dose was 9.6×1016 ions/cm2, the χ(3) value was minimized to be 1.5×10-10 esu. Moreover, the mechanism responsible for the enhancement of χ(3) value was also discussed tentatively.
    Synthesis and Characterization of PLGA-(ASP-DIOL)-x-PLGAs Copolymer Containing Pendant Amino Groups with Different Densities
    ZHAO Jie, QUAN Da-Ping, LIAO Kai-Rong, WU Qing
    2005, 26(8):  1565-1569. 
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    A series of poly(ASP-Diol)-xs were prepared by polycondensation reactions of N-CBz-L-aspartic acid anhydride with diols of different molecular weights including ethylene glycol, triethylene glycol, PEG200 and PEG600, respectively. They were used as the macromonomer initiators respectively to synthesize biodegradable copolymers PLGA-(ASP-Diol)-x-PLGAs containing pendant amino groups with different contents by ring-opening copolymerization of lactide/glycolide(molar ratio 75/25). Their structures were confirmed by 1HNMR, FTIR, EA, DSC and GPC. The results indicate that the main factor that affects the molecular weights of the prepolymers is not the molecular weights of diols, but the activity of the end hydroxyl groups. With increasing the chain length of the diols, the content of amino groups in the copolymers decreased, and the glass translation temperature(T-g) decreased obviously, therefore, it is considered that the content and distribution of amino groups in the copolymers can be effectively adjusted by changing the chain length of the diols.
    Reverse Atom Transfer Radical Polymerization of MMA Catalyzed by FeBr3/Me-6TREN
    LI Zhong-Hui, ZHANG Yong-Ming, LIU Yan-Fei, XUE Min-Zhao, LIU Yan-Gang
    2005, 26(8):  1570-1573. 
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    The reverse atom transfer polymerization of MMA catalyzed by FeBr3/Me-6TREN was studied in this paper. The molecular weight increased with the increase of the conversion and was in a good agreement with the theoretical value. The molecular weight distribution of the resulted PMMA was very narrow(1.06). These results indicate that the polymerization was well-controlled. The effect of morlar ratio of catalyst to initiator and FeBr3 to ligand Me-6TREN on the control of the polymerization were studied. In addition, the activation energy of polymerization of MMA was calculated to be 29.35 kJ/mol, which was a bit smaller than that of Cl-mediated reverse ATRP.
    Synthesis and Characterization of Poly(aryl ether ketone)s Containing Silican
    GAO Zi-Hong, FAN Xing-He, CHEN Xiao-Fang, ZHOU Qi-Feng
    2005, 26(8):  1574-1578. 
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    The introduction of silane into the polymer backbone improves the solubility of the polymer without having a great influence on the thermal stability of the polymer. Therefore, the changes on the main-chain of PAEK were made to gain novel materials containing silane and all the polymers were prepared by low temperature polycondensation method. The glass transition temperatures were evaluated by differential scanning calorimetry(DSC) and the thermal properties were tested by thermal gravimetric analysis(TGA) which showed no mass loss below 350 ℃ in both air and nitrogen atmospheres. All the polymers were completely soluble in organic solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulphoxide(DMSO), and concentrated sulfonated acid(H2SO4-). All these PAEK materials containing silane, which show excellent properties, were expected to be applied in composition or function material system.
    Studies on Nano Zirconium Dioxide Modified Poly(ether-sulfone)
    ZHOU Hong-Wei, MA Jia, LI Zhi-Cheng, CHEN Chun-Hai
    2005, 26(8):  1582-1584. 
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    Blends of inorganic nano zirconium dioxide(ZrO2-) and poly(ether-sulfone)(PES) were prepared by mechanical blending. Their mechanical, thermal and electrical properties were investigated. Compared with pure PES, this kind of organic/inorganic nano-composite exhibit a better electrical property, lower coefficients of thermal expansion, as well as a similar thermal properties. The mechanical properties are composition-dependent.