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    10 June 2008, Volume 29 Issue 6
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    高等学校化学学报2008年第29卷第6期目次
    2008, 29(6):  0.  doi:
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    下期目次预览
    2008, 29(6):  0.  doi:
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    研究论文
    Synthesis, Structure and Magnetic Property of a Terephthalato-bridged Nickel(Ⅱ) Tetraazamacrocyclic Complex
    JI Cong-Min, ZHANG Bing, CUI Ai-Li*, KOU Hui-Zhong
    2008, 29(6):  1077-1080.  doi:
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    A new terephthalato-bridged nickel(Ⅱ) complex with a teraazamacrocyclic ligand, [Ni(L)tp]∞(L=5-benzyl-4,6-bimethyl-1,3,7,10-tetraaza-cyclotetradecane) was synthesized and characterized. On the basis of the X-ray crystallographic study, each Ni(Ⅱ) ion lies in a distorted octahedral environment, and the terephthalato ligand bridges two Ni(Ⅱ) ions in a trans fashion. The [Ni(L)]2+ and the tp2- groups are alternatively arranged yielding a one-dimensional coordination polymer. Magnetic measurements show that the decrease of χmT below 25 K gave a Weiss constant of θ=-0.49 K. This behavior may be due to a very weak intrachain magnetic superexchange through the tp2- bridge, a weak interchain exchange interaction and the zero-field splitting(ZFS) of octahedral Ni(Ⅱ) ions.
    Syntheses, Structures and Luminescent Properties of Heterodinuclear Cd-Ln Coordination Compounds
    CHI Yu-Xian, NIU Shu-Yun*, WANG Zhao-Long, JIN Jing
    2008, 29(6):  1081-1085.  doi:
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    Three novel heterodinuclear d-f coordination compounds [LnCd(C8H7O3)5(phen)(H2O)](Ln=Dy(1), Pr(2), Gd(3); C8H7O3=4-methoxy-benzoate; phen=1, 10-phenanthroline) were synthesized by the hydrothermal method, and their structures were determined by single-crystal X-ray diffraction. They are isomorphous. In each molecule the Cd2+ ion is five-coordinated and the Ln3+ ion is eight-coordinated, which are bridged by three 4-methoxybenzoates. In addition, two neighboring molecules are connected with hydrogen bonds, forming dimers in their crystal. The IR, UV-Vis-NIR absorption, the excitation and emission spectra of the three complexes were determined at room temperature. The associations between the UV-Vis-NIR absorption spectra and the emission spectra of the complexes were analyzed and the influences of the d-block component on the luminescence of Ln3+ were discussed.
    Synthesis and Crystal Structure of a Novel Chiral Coordination Polymer [Zn2(C7H8O6)2(bipy)2(H2O)2]·4H2O
    MENG Xiang-Hua, SHI Ji-Cheng*, TONG Qing-Song, YANG Yu-Rong, JIA Li
    2008, 29(6):  1086-1089.  doi:
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    A novel chiral coordination polymer, [Zn2(C7H8O6)2(4,4'-bipy)2(H2O)2]·4H2O(C7H8O6=2,3-O-isopropylidene-L-tartrate, bipy=4,4'-bipyridine), was synthesized via a solvothermal reaction and characterized by elemental analyses, TG, IR and single crystal X-ray diffraction. The analysis results of crystal structure show that the complex is monoclinic with space group C2, a=2.02334(14) nm, b=1.13896(4) nm, c=1.01091(6) nm, β=117.366(3)°, V=2.0689(2) nm3. Both crystallographically unique Zn atoms exit as an octahedral geometry. The four equatorial positions of Zn1 atom are occupied by the carboxylate-oxygen atoms of the two tartrates, and the two oxygens of the left four carboxylate-oxygen atoms coordinate to two different Zn2 atoms, respectively, forming infinite coordination polymer chains. The left two of the trans equatorial positions of Zn2 atom are completed with two oxygen atoms of two water molecules. The axial positions of both Zn atoms are occupied by the nitrogen atoms from different 4,4'-bipyridine molecules to give a 2D rectangular-grid layers with a cavity dimension of 0.51165(3)nm×1.13896(5) nm. A three dimensional network is formed by the crystallization water chains joined by the carboxylate-oxygen atoms through hydrogen-bonding interactions.
    Preparation of Gold Nanoshell Based on the Core of Carbon Microspheres

    CHEN Shi-Xin, WANG Chang-Chun*

    2008, 29(6):  1090-1094.  doi:
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    This article reported a new method to synthesize Au nanoshell via carbon nanoparticle as the dielectric core. The carbon nanoparticles were prepared through hydrothermal reaction of glucose and Au seeds. This carbon nanoparticles inherit reactive surfaces which facilitate the loading of Ag nanoparticles, then the Ag nanoparticles act as the seeds for further reduction of chloroaurie acid in the presence of cetyltrimethyl ammonium bromide(CTAB) and ascorbic acid to form a complete Au nanoshell on the surface of carbon nanoparticles(carbon nanoparticle as the core and Au layer as the shell). Successful forming of complete Au nanoshell was approved by transmission electron microscopy(TEM) and UV-Vis absorption spectra. The Au nanoshell shows a strong absorption in the range of near-infrared(NIR). The experimental results indicate that this method is a facile and effective way for the synthesis of Au nanoshell with NIR absorption properties.
    Preparation of MoO3/Aniline Layered Composite Material
    XIANG Yi-Xian, DONG Xiao-Wen, PAN Qing-Yi*, CHENG Zhi-Xuan, XU Jia-Qiang
    2008, 29(6):  1095-1098.  doi:
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    Molybdenum oxide/aniline composite material with layered structure of [ANI]0.4MoO3 was prepared indirectly with molybdenum oxide/dodecylamine as the starting material. This composite was characterized via powder X-ray diffraction, scanning electron microscopy, elemental analysis, infrared spectroscopy and thermal analysis. The results show that the intercalation of aniline successfully proceeds in the present process. The layered morphology of the parent oxide is maintained. The intercalated ANI expanded the interlayer spacing of MoO3 from 0.692 nm to 1.318 nm with the gallery height 0.626 nm. A possible arrangement of intercalated aniline in the gallery of MoO3 was proposed. The interaction between the inorganic host and the organic guest was discussed. The intercalation mechanism of aniline was also discussed.
    研究快报
    Synthesis of Zeolite Silicalite-1 with Chain-like Morphology
    WANG Li-Feng, ZHU Guang-Shan, QIU Shi-Lun*
    2008, 29(6):  1099-1101.  doi:
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    The synthesis of zeolites with special morphologies has attracted much attention, because the morphologies influence the efficiency of catalysis, applications as the hosts for micro-devices, and so on. Silicalite-1 with chain-like morphology (0.57—6.33 m) were synthesized successfully with poly(diallyldimethylammonium chloride) (PDDA) as an additive and was characterized by XRD and SEM. The PDDA as the additive in the synthesis system was the real key for the formation of the chain-like morphology of the products. The length and the diameter of the material can be tuned through adjusting the molar ratios of PDDA and TPAOH. The straight channels of materials are longer and their openings are much fewer than those of the traditional slicalite-1 crystals, because of the crystal stacking along the b axis.
    研究论文
    Preparation of (R)-(+)-1,1'-Binaphthyl-2,2'-diamine Polymer as a Novel Chiral Stationary Phase by Surface-initiated Polymerization and Chromatographic Evaluation
    YAO Na1,2, SONG Rui-Juan1,2, FU Yu1,2, SHI Hong-Yu1,2, LONG Yuan-De1*, HUANG Tian-Bao1
    2008, 29(6):  1102-1106.  doi:
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    A novel brush-type chiral stationary phase(CSP-a) for HPLC was prepared by surface-initiated polymerization with (R)-(+)-1,1'-binaphthyl-2,2'-diamine as a chiral monomer and dichloride of 4,4'-azobis-4-cyanopentanoic acid bonded on the surface of silica gel as a radical initiator. The resolutions of the enantiomers of binaphthol derivatives, N-3,5-dinitrobenzoyl-D,L-amino acid methyl esters and isopropyl esters, and a trans-ethylene oxide derivative on CSP-a were carried out using heptane-alcohol-organic modifier-organic acid as the mobile phases under the detection conditions of the column temperature of 30 ℃ and UV wavelength of 254 nm. The effects of organic modifier and organic acid on the resolutions of the analytes on CSP-a were examined. The results show that CSP-a prepared was effective for the resolutions of the enantiomers of π-acid and π-base derivatives. Trifluoroacetic acid was a better organic modifier than acetic acid. Adding CH2Cl2 and CHCl3 to the mobile phase could increase retention and resolution of the samples on CSP-a.
    Studies on Structure-activity Relationship of 17 Sulfonamides Binding to Antibody by Fluorescence Polarization Immunoassay
    WANG Zhan-Hui, ZHANG Su-Xia, DING Shuang-Yang, SHEN Jian-Zhong*
    2008, 29(6):  1107-1111.  doi:
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    Fluorescence polarization immunoassay for the determination of sulfamethazine was developed via four polyclonal antibodies against sufamethazine and five fluorescein-labeled sulfonamides(tracers). The study mainly focuses on the relative affinity trend of four polycolnal antibodies toward 17 sulfonamides analogs and explaination of the recognition between antibody and drugs based on the two-dimensional structures of drug antigen. The results demonstrate that the polyclonal antibody(No.3) showed the most sensitivity for sulfamethazine, however, the four polyclonal antibodies presented a similar relative affinity trend to 17 sulfonamides, implying that the affinity of antibody to antigen has correlationship with the chemical structure of antigen.
    Supramolecular Monitoring and the Related Mechanism of Aggregation/Disaggregation of Melittin in Different Media
    WANG Lei1, HAO Ya-Qiong1, LI Yue1, LI Zheng-Qiang3, WU Yu-Qing1,2*
    2008, 29(6):  1112-1115.  doi:
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    Melittin, with strong pharmacological effects and biological activity, is the major component of bee venom. The physiological function of melittin depends upon its secondary structure and aggregation state due to which the peptide loses its activity. Once the aggregation/disaggregation processes can be effectively monitored, it will lay the foundation for clinical applications by exploring its function and mechanism. In this paper the aggregation/disaggregation processes were explored, the related mechanism and the α-helix content of melittin in aqueous solution is controlled by 2-hydroxypropyl-β-cyclodextrin, sodium chloride or 1,2-dioleoyl-sn-glycero-3-phosphocholine(DOPC) through fluorescence spectra and circular dichroism(CD).
    Far-IR and THz Absorption Spectra Studies of Cholic Acid and Deoxycholic Acid
    YANG Li-Min1*, ZHAO Guo-Zhong2, ZHAO Kui1, SHI Xiao-Xi2, JIA Xin-Feng2, WENG Shi-Fu3, XU Yi-Zhuang3, LU Xiang-Yang1, XIE Da-Tao1, WU Jin-Guang3, CHEN Jia-Er1
    2008, 29(6):  1116-1121.  doi:
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    Cholic acid(HC) and deoxycholic acid(HDC) are main components of bile and have an important biological function in human body. In this paper the two polycrystalline molecules were studied via far-IR and THz absorption spectroscopy. Their characteristic bands in far-IR and THz region were observed. Some similar bands appear in the far-IR region for the two molecules because they have similar structures. There are two bands at 1.26 and 2.02(e.g. 42 and 67 cm-1) in the THz spectrum of cholic acid molecule, and 1.13, 1.26, 1.69 and 2.17 THz(e.g. 38, 42, 56, 72 cm-1) in the THz spectrum of deoxycholic acid. The results indicate that far-IR and THz results are consistent in some extent. The bands related to COOH were considered in the far-IR and THz region. Omnic 5.0 program was adopted to treat the data and the bands with a low signal-noise ratio were emphasized via this method. And many sub bands were observed, which indicate that complicated hydrogen bond networks exist. The difference in the structures of the two molecules is only one hydroxyl group, but their far-IR and THz absorption spectra have many differences, which may be caused by the differences of their molecule structures, for example, different hydrogen bonding networks and the various packing of CH chain, etc.. The results indicate that far-IR and THz absorption spectra are effective methods for investigating biomolecules and distinguishing their structures.
    Simple and Fast Dimerization of Terminal Alkynes
    ZHU Min*, XU Hui-Ying, CHEN Hong
    2008, 29(6):  1122-1124.  doi:
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    Diacetoxyiodo benzene(DIB) is an important and practically useful commercial available compound. In order to explore DIB useful scope as an environmentally more benign oxidizing reagent, a novel and efficient synthesis of diynes was studied in the absence of palladium catalysts. It was found that terminal alkynes were reacted with DIB, CuCl and Et3N in CH3CN at room temperature, diynes were prepared in good yields in a short time, which providing a simple method for the synthesis of diynes.
    Pharmacophore Model Construction of 5-HT3 Receptor Antagonist
    BAO Hong-Juan, ZHANG Yan-Ling, QIAO Yan-Jiang*
    2008, 29(6):  1125-1132.  doi:
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    A three-dimensional pharmacophore model of 5-HT3 Receptor Antagonists was developed based on 31 5-HT3 Receptor Antagonists which antagonizes the von Bezold-Jarisch reflex evoked by 5-HT in anesthetized rats. The antagonists were selected with great diversity in both molecular structure and bioactivity as required by HypoGen program in the Catalyst software. The antagonists in training set show 5-HT3 Receptor inhibiting activity with ED50 values, and the range of values is 0.05—320 μg/kg i.v.. The best statistical hypothesis, consisting of four features, one hydrogen-bond acceptor, one hydrophobic region, one ring aromatic feature, one positive ionizable and six excluded volumes, has a correlation coefficient of 0.9031, a root-mean-square deviation of0.8976, a fixed cost of112.6, a null cost of 172.0, a configuration cost of 7.248. The pharmacophore model has a highly predictive ability, which was approved by the results of the activity estimated by mapping the compounds of training set with it. On the basis of Fischer method, the cross-validation provided a strong confidence on this hypothesis. This pharmacophore model can contribute to the finding and designing of new-type 5-HT3 Receptor Antagonists.
    Synthesis and Application of 1-(8-Quinoline)-3-(pyridyl)-triazene
    WANG Cheng2, FENG Feng1,2*, CHEN Ze-Zhong1, LU Zhen1, BAI Yun-Feng1, MENG Shuang-Ming1, LIN Sen2
    2008, 29(6):  1133-1136.  doi:
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    Through combinination of 8-aminoquinoline with pydine through triazene group, a new fluorescent reagent 1-(8-quinoline)-3-(pyridyl)-triazene(QPyT) was synthesized. The product was confirmed by means of elemental analysis, 1H NMR and infrared spectra. Its excitation and emission wavelengths were 216 nm and 343 nm in a basic medium, respectively. This new reagent reacted with Pb(Ⅱ) in a slightly basic medium to form a 1∶1 complex, by which lead ion caused the fluorescence quenching of the new fluorescent reagent. The possible response mechanism of QPyT to Pb(Ⅱ) was discussed. The reaction showed a high selectivity and a high sensitivity for Pb(Ⅱ). The new fluorescent reagent was used to determined trace Pb(Ⅱ). The optimum analytical conditions for Pb(Ⅱ) assay were established. Under these conditions, the linear range of Pb(Ⅱ) was from 1.6×10-7 to 1.2×10-5 mol/L, with a detection limit 9.0×10-8 mol/L. The method is selective, sensitive and simple. It was used for the determination of trace Pb(Ⅱ) in water sample with satisfactory results.
    Synthesis of Thiocarbamates via Selenium-mediated Carbonylation of Aniline with Thiols
    ZHANG Xiao-Peng1,2, LU Shi-Wei2*
    2008, 29(6):  1137-1140.  doi:
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    In order to develop a new and facile route to the syntheses of thiocarbamates, selenium-mediated carbonylation of aniline with thiols was studied. Mediated by selenium, aniline reacted readily with carbon monooxide and thiols to afford thiocarbamates under the conditions of ambient temperature and atmospheric pressure. The results show that the reaction can proceed well to thiocarbamates in high yields with less hindered alkyl thiols. Selenium could be easily recovered and recycled.
    Design, Synthesis and Bioactivity of Long Acting LHRH Antagonists
    ZHOU Ning1, RONG Di2, CHENG Jun-Ping1, ZHOU Wen-Xia1, ZHANG Yong-Xiang1, CHENG Mao-Sheng2, LIU Ke-Liang1*
    2008, 29(6):  1141-1144.  doi:
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    Based on a new concept of protease-resistant long acting peptides design, the functional groups with proton-donors and proton-acceptors were introduced to the N-terminal and position 6 of LHRH antagonist, and a series of novel LHRH antagonist analogues were synthesized. The bioactivity of them was evaluated in rats by a testosterone test model. The designed peptides showed a longer duration of inhibiting testosterone secretion than the parent peptide and control. Peptide 1e inhibited the testosterone secretion for 48 h in intact rats(Cetrorelix: 8 h). The experimental results not only support the proposed concept of the long acting peptide design, but also supply some new candidate compounds for the development of long acting LHRH antagonist drugs.
    Comparison of the Reactivity Between 1,4- and 1,2-Dihydro NADH Models
    JIAO Xiao-Yun, Zhang Ming-Tian, ZHU Xiao-Qing, CHENG Jin-Pei*
    2008, 29(6):  1145-1148.  doi:
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    Two series of NADH models: p-G-PNAH-1,4-2H and p-G-PNAH-1,2-2H are synthesized. The rate constants at different temperatures and the activation parameters for the reaction of two oxidants(p-chloranil and TMPA+·) with these NADH models were determined in acetonitrile. The kinetics results reveal that the reactivity of 1,2-2H-isomer and 1,4-2H-isomer can be controlled by the remote substitutions. The reaction between GPNAH and p-chloranil was controlled by entropy while the reaction between GPNAH and TMPA+· was controlled by enthalpy and entropy together. And the substituted effect of 1,2-2H-isomer is bigger than 1,4-2H-isomer.
    Separation, Purification and Structure Analysis of an Extracellular Polysaccharides from Antarctic Bacterium Pseudoalteromonas sp. S-15-13
    LI Jiang1*, SONG Guo-Qiang2, CHEN Kao-Shan1,3, LI Guang-You1
    2008, 29(6):  1149-1152.  doi:
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    An immunoactive extracelluar polysaccharide was isolated from Pseudoalteromonas sp. S-15-13, a bacterium screened from Antarctic sea-ice. In order to accurately define the structure of the Antarctic bacterial EPSs and to relate these findings to the function of these molecules in the natural environment, purification and structural analysis of S-15-13 EPSs was carried out. Exopolysaccharide fractions were extracted and were purified by DEAE-Sephadex A-50 ion-exchange and Sephadex G-100 gel chromatography to give EPS-Ⅱ. The EPS-Ⅱwas eluted as a single peak in HPLC analysis, indicating that the homogeneity and purity of EPS-Ⅱwere suited to the structural analysis. The molecular weight of the EPS-Ⅱ was determined as 62000 by the HPLC method. Sugar composition analysis, methylation analysis and one-dimensional and two-dimensional NMR spectroscopies reveal that the main structure of EPS-Ⅱwas a 1,2 linking mannan with fewer 1,2,6-linking branch, a new extracelluar polysaccharide from Antarctic bacterium.
    Fluorescence Switch of Tweezers-type Bis(zinc porphyrin) Complex Regulated by Double Guests of Cu+ Ion and DABCO
    ZHOU Zai-Chun1,2, ZHU Yi-Zhou1, ZHENG Jian-Yu1*
    2008, 29(6):  1153-1158.  doi:
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    A new tweezers-type bis(zinc porphyrin)(1), 1,8-bis{4-[N-(N,N-zinc-5,10,15,20-tetraphenylporphyrin-4'-yl)-amino carbonyl]benzyloxy}anthraquinone, with double inclusion function area can accommodate Cu+ ion or DABCO(1,4-diazabicyclo[2.2.2]octane). Both of Cu+ ion and free DABCO can lead to fluorescence quenching of compound 1. The former is due to occurrence of PET after complexation and the latter is due to the occurrence of dynamic fluorescence quenching. Both DABCO and Cu+ ion can capture mutually in the solution due to the formation of their complexes. A controllable off/on fluorescence molecular switch process is proposed by addition of the two guests.
    研究论文
    Preparation of Adsorbents for Oligopeptide and Adsorption Mechanism
    LI Ji-Hong1,2, ZHANG Yuan-Wei1, YANG Mei1, ZHANG Jing1, MA Yi1, YUAN Zhi1*
    2008, 29(6):  1159-1162.  doi:
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    Octapeptide VVRGCTWW(V8) is an oligopeptide separated from the blood serum of uremic patients. To remove it, some adsorbents containing phenyl group with different length spacers were prepared. The result of adsorption experiments shows the adsorbent Phe3c had the highest adsorption capacity to V8. Molecular simulation technology and NMR were used to study the adsorption mechanism. The results demonstrate that the phenyl group in ligands could form π-π stack with Trp residue in octapeptide. Moreover, the strength of the interaction between the octapeptide and adsorbents could increase with the growth of the spacer, because the increasing length of spacer could overcome the space hinder. In a conclusion, under the condition of adoption of reasonable molecular models, the molecular docking could be used to virtually screen the adsorbents for oligopeptide, and to study the adsorption mechanism.
    研究快报
    Bioactivity and Structure of Analogues of Exendin-4
    SONG Xiang-Wei1, WANG Xue-Li2, XIONG Xin-Hui1, NIU Jian-Li1 , WANG Shi-Qing3, WANG Li-Ping1*, LI Wei1
    2008, 29(6):  1163-1165.  doi:
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    Exendin-4 is an incretin mimetic that has been studied as a potent drug for the treatment of the type 2 diabetes. To screen the shorter analogues of Exendin-4 that have the same bioactivity, we designed two analogues of Exendin-4: Ex1, deleting this sequence and Ex2, replacing this sequence with three Alas. The proliferation assay of RINm-5F cell using MTT suggested the bioactivity of Ex1 and Ex2 was lower compared to that of Exendin-4 caused by the deletion of LSKQMEEEA. Ex1 and Ex2 had the same strong stability against DPPⅣ with Exendin-4. CD data suggested the helix content of Ex1 had a significant lost, but the helix content of Ex2 was the same as that of Exendin-4. The emission maximum of Ex1 was red-shifted of 3 nm relative to Exendin-4, the absence of this sequence made Trp25 more apt to hydrophilic and the Trp-cage became looser. So we have designed Ex2, the mimetic of Exendin-4 that had the same bioactivity and strong stability against DPPⅣ with Exendin-4 successfully. It became a solid foundation for designing shorter analogues of Exendin-4 for oral drug of diabetes.
    研究论文
    Ultrasonic Wave-assisted Synthesis of CdTe Semiconductor Nanocrystals in Water Applied to Biolabel of Micoorganism
    LIU Yan1, ZHOU Jian-Guang1,2, SHEN Qi-Hui3, YU Dong-Dong4, JIN Li1, FAN Hong-Liang2, JIN Qin-Han1,2*
    2008, 29(6):  1166-1170.  doi:
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    Taking advantages of ultrasonic wave-assisted synthesis CdTe semiconductor nanocrystals were synthesized under mild conditions. As compared with traditional methods, the time and cost for the preparation of the CdTe nanocrystals were reduced, and on the other hand, the photoluminescence quantum yield(50%) of the as-prepared CdTe semiconductor nanocrystals was improved. Furthermore, we have succeeded in detecting the living Borrelia burgdorferi of Lyme disease by its photoluminescence image using CdTe nanocrystals.
    Geometry of Hydrotalcite Slab with n(Mg)/n(Al)=3 and Regulation Effect of Interlayer Spacing with Anion
    LIU Ya-Hui, GUO Yu-Hua, WU Jing-Yi, LIU Ling-Yan, HE Jing, CHEN Biao-Hua, PU Min*
    2008, 29(6):  1171-1175.  doi:
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    The slab microstructure of layered double hydroxide(LDH) with n(Mg)/n(Al)=3 is studied via density functional theory at the B3PWP91/Lanl2dz level. The optimized geometric parameters and the simulated XRD patterns of hydrotalcite are in agreement with experimental results. The structural simulations of hydrotalcite show that the host layers stack along the c-axis according to space group R3m, a=1.2552 nm, c=2.3400 nm. On the basis of the stacking multilayer model, the carbonate anion is introduced into the interlayer space and one special cluster structure is obtained through optimization under the condition of keeping space group R3m. The computation results indicate that the interlayer spacing of hydrotalcite with removed crystal water is 0.7260 nm. The changes of bond parameters of cluster suggest that there are strong supramolecular interactions between the slabs and anion.
    Preparation of Ultrasound Contrast Microbubbles via Double Emulsion/Solvent Evaporation Process
    LU Rong, DOU Hong-Jing, SUN Kang*
    2008, 29(6):  1176-1180.  doi:
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    In this paper, water in oil in water(W1/O/W2) double emulsion/solvent evaporation process was used to prepare poly(L-lactic acid)(PLLA) microbubbles. With the characterization technique of SEM, CLSM and PSA, we investigated how the experimental parameters would influence the properties of microbubbles. The results demonstrate that poly(vinyl alcohol)(PVA) was an excellent emulsifier in the outer aqueous phase for this system. By changing the concentration of PVA aqueous solution or the speed of homogenizer during the second emulsification, the average size of microbubbles can be controlled between 1 μm to 10 μm. The ratio of water to oil at the first emulsification will affect the hollow ratio of microbubbles to a great extent. It was confirmed that gas-filled PLLA microbubbles has an excellent ultrasound contrast ability.
    π-π Interactions in DPP-11 Supramolecular Micellar Aggregates Under High-pressure
    LIN Ao-Lei, WANG Kai, ZHAO Yu, ZOU Bo*
    2008, 29(6):  1181-1184.  doi:
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    In-situ synchrotron X-ray diffraction and far-IR spectra of DPP-11{2,5-bis[11-(1-pyridinium)alkyl]-3,6-bis(2-thienyl)-1,4-dioxopyrrolo[3,4-c]pyrrole ditosylate salts} and its micelles in aqueous solution were studied. Although X-ray studies show no indication of phase transition, however, the π-π interactions become stronger with increasing pressure which can be deduced from far-IR spectra. A new far-IR absorption peak is found to be related to the π-conjugated aromatic dyes in DPP-11 micelles. Upon increasing pressure, the peak shifted toward higher wavenumber region due to the stronger π-π interactions.
    Effect of Arginine Residue on the Fragmentation of Protonated Peptide RRMKWKK Under Collision-induced Dissociation
    ZHANG E1, ZU Li-Li1*, FANG Wei-Hai1, HUANG Ling-Yun2, HE Da-Chen2
    2008, 29(6):  1185-1189.  doi:
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    Collision energy and fragmentation pathways of doubly- and triply-protonated peptide RRMKWKK upon low-energy collision-induced dissociation(CID) were investigated with ESI-MS/MS. Triply-protonated ion dissociated more easily than the doubly-protonated ion, with a dependence of the number of charges vs. the number of the arginine residues in the peptide. The two basic Arg residues were the primary charge location, resulted in a high dissociation energy for Arg-contained peptides. The protonated ions with one more proton than the number of Arg residues in the peptides were suggested when Arg-containing peptides were studied by using mass spectroscopy. Secondary structures of the protonated RRMKWKK calculated by AM1 method indicate that the two protons locating at the basic side chains of the two adjacent Arg were separated in space, so that Coulomb repulsion did not affect the proton location.
    Effect of SnO2-TiO2 Film Support on Electrocatalytic Properties of Au-Pt Nanoparticles
    YU Zhi-Hui, XIE Jia, XIA Ding-Guo*
    2008, 29(6):  1190-1194.  doi:
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    SnO2-TiO2 thin films were deposited on the activated glassy carbon electrodes by vacuum coating method. Au-Pt/SnO2-TiO2/GC composite electrode was prepared by reducing HAuCl4 and H2PtCl6 mixture solution and sediment Au-Pt bimetallic nanoparticles successively on the SnO2-TiO2/GC.The effect of SnO2-TiO2 film support on the electrocatalytic properties of Au-Pt nanoparticles was characterized via cyclic voltograme method. The morphological and structural properties of Au-Pt nanoparticles self-assembled on SnO2-TiO2 film were characterized via Scanning Electron Microscope and X-ray Photoelectron Spectroscopy. The results show that the compact and uniformed 10 nm Au-Pt nanoparticles were self-assembled on SnO2-TiO2 film. The ability of anti-CO poisoning was enhanced with the function of SnO2-TiO2 support. The form of Au-Pt alloy enhanced the electrocatalytic oxidation of methanol in acidic system. Furthermore, the increase of d vacancy with the function of SnO2-TiO2 support improved the stability and catalytic property of Au-Pt bimetallic nanoparticles.
    Photoelectrochemical Properties of TiO2 Coated on Carbon Nanofibers with Different Microstructure Film Electrodes
    LI Zhi-Zhou1,2, CUI Xiao-Li2* , ZHENG Jun-Sheng3, WANG Qing-Fei1
    2008, 29(6):  1195-1199.  doi:
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    Novel nanocomposites of TiO2 and two kinds' carbon nanofibers with different microstructure were prepared by sol-gel method. The nanocomposites were studied via SEM, XRD, and photoelectrochemistry. The potential dependence of photocurrent and the photocurrent transients indicate that the nanocomposite shows characteristics of n-type semiconductor. The experimental results demonstrate that the PCNF/TiO2 shows a higher photoelectrochemical response and sensitivity for visible light illumination than FCNF/TiO2 and pristine TiO2. This is likely because of the specific microstructure of the PCNF, which possesses large numbers of active edge sites and provides many favorable sites for electron transfer as well as a very large working surface area. The significant enhancement of the photoelectrochemical response of the CNF toward visible light responses may result from the difference of their morphologies as well as their textural properties and crystalline structure. The results show that PCNF and FCNF are thus very promising candidates for developing a class of ideal and novel modified photoelectrodes.
    Comb-like Block Copolymer Microphase Separation Studied by Dissipative Particle Dynamics Simulations
    LIU Ying-Tao, LI Zhan-Wei, LÜ Zhong-Yuan*, LI Ze-Sheng
    2008, 29(6):  1200-1204.  doi:
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    Dissipative particle dynamics simulations are carried out to study the microphase separation of comb-like block copolymer in two dimensions. By systematically varying the side chain lengths and the repulsion strength between the two components, we find various morphologies. For comparison, the linear and star-like block copolymers are also studied in the simulations. The results reveal the main factors that affect the microphase separation of comb-like block copolymers in melts.
    Preparation and Photocatalytic Properties of Magnetically Separated Nitrogen-doped TiO2
    XU Shi-Hong1*, FENG Dao-Lun2, SHANGGUAN Wen-Feng3, LI Deng-Xin1
    2008, 29(6):  1205-1210.  doi:
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    A magnetically separated nitrogen-doped photocatalyst TiO2-xNx/SiO2/NiFe2O4(TSN) with a typical ferromagnetic hysteresis was prepared by a simple process: the magnetic SiO2/NiFe2O4(SN) dispersion and the visible-light-active photocatalyst TiO2-xNx were mixed, sonificated, dried, and calcined. The catalyst shows a photocatalytic activity for the degradation of methyl orange in water under visible light irradiation(λ>400 nm). X-ray diffractometer(XRD) and transmission electron microscope(TEM) were used to characterize the structure of photocatalyst TSN. The results indicate that the magnetic SN nanoparticles adhered to the surface of TiO2-xNx congeries. The degradation experiments of methyl orange indicate that the thin SiO2 layer between NiFe2O4 and TiO2-xNx could improve the photocatalytic activity of TSN.
    Thermochemistry Study on Interaction Between Anti-tumor Drug Tegafur and Bovine Serum Albumin
    LI Lin-Wei*, WANG Dong-Dong, SUN De-Zhi, WEI Xin-Ting, LIU Min, ZHAO Qiang
    2008, 29(6):  1211-1215.  doi:
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    From the assumptions of this binding system and the Langmuir's binding theory, the interaction between tegafur and bovine serum albumin(BSA) was investigated by the nano-watt-scale isothermal titration calorimetry and the circular dichroism(CD) spectrometry at 298.15 K. The results show that there are two classes of binding sites on the protein BSA for tegafur. For the first class of binding, the binding site number is N=52.00±0.12, the binding constant is K=(9.83±0.13)×104 L/mol, the binding enthalpy is ΔH=(30.10±0.17) kJ/mol, the binding entropy is ΔS=(196.00±0.65) J/(mol·K), and the binding Gibbs free energy is ΔG=(-28.50±0.66) kJ/mol. This binding is an entropy driven process, and the hydrophobic interaction is the main motive-force for the process. For the second class of binding, the binding sites number is N=86.00±0.14, the binding constant is K=(9.35±0.13)×104 L/mol, the binding enthalpy is ΔH=(-19.80±0.17) kJ/mol, the binding entropy is ΔS=(28.30±0.50) J/(mol·K), and the binding Gibbs free energy is ΔG=(-28.40±0.43) kJ/mol. This binding is an enthalpy-entropy synergically driven process, and the hydrogen bond and electrostatic interactions are the main motive-force for the process. The analytical results of circular dichroism(CD) spectra show that the interactions between tegafurl and BSA resulted in the change of the relative contents of secondary structure units of protein BSA in these two classes of the binding processes. The thermodynamic effects of the binding system are integrated results which come from different interactional effects in the binding process. The conformations of the protein BSA underwent changes induced by the anti-tumor drug tegafurl in the solution medium of this binding system.
    Transfer Behavior of Ferrocene in Various Ionic Liquids
    LIU Xiu-Hui, DONG Cun-Wu, YANG Jun, ZHANG Kai, LU Xiao-Quan*
    2008, 29(6):  1216-1219.  doi:
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    The transfer behavior of ferrocene(Fc) in various ionic liquids was investigated with cyclic voltammetry, and the diffusion coefficients of Fc in various ionic liquids and the viscosity of ionic liquids were estimated in this paper. In addition, we also discussed the relationship between viscosities and structures of ionic liquids. Our experimental results demonstrated that the viscosities of ionic liquids increase with increasing the alkyl chain length of cation and symmetry of anion structure of ionic liquids.
    Preparation, Characterization and CO Oxidation Catalytic Properties of CuO/TiO2 Catalysts Supported on Porous Microspheres Composed of TiO2 Nanocrystals
    GUO Xian-Zhi*, HUANG Jing, WANG Yan-Mei, WANG Shu-Rong, ZHANG Bao-Long, WU Shi-Hua
    2008, 29(6):  1220-1223.  doi:
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    The porous TiO2 microspheres were prepared by the reversed-phase suspension polymerization and sol-gel method. The CuO/TiO2 catalysts with porous microspheres composed of TiO2 nanocrystals as the support were prepared by impregnation method. The properties of the porous TiO2 microspheres and CuO/TiO2 catalysts were studied by TG-DTA, X-ray diffraction, XPS and ICP. The catalytic properties of the catalysts for CO oxidation were studied via a microreactor-GC system. The results show that the porous microspheres were mainly composed of anatase TiO2 nanocrystals with a size of 19.5 nm. The XPS results indicate that there was interaction between the support and the active component, and Cu mainly existed as Cu2+ with some other form. The catalytic activity of the catalysts depends on the concentration of the impregnation solution and the calcination temperature of the CuO/TiO2 catalysts. The catalyst impregnated in 0.5 mol/L Cu(NO3)2·3H2O had a better catalytic activity. The optimum calcination temperature of the CuO/TiO2 catalysts was 200 ℃.
    Theoretical Study of Effect of Solvent on the Mechanism of Reaction of Pentafulvenone with Hydrocyanic Acid
    JIA Xiu-Juan, PAN Xiu-Mei*, WANG Li-Wei, LIU Ying, SUN Hao, SU Zhong-Min, WANG Rong-Shun
    2008, 29(6):  1224-1227.  doi:
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    Theoretical investigation of the solvent effects on the mechanism of the reaction of pentafulvenone with hydrocyanic acid to produce the main product of acid of type b was carried out at B3LYP/6-311+G** level via the conductor-like polarizable continuum model(CPCM). The calculation results show that the reaction mechanism in solvent is consistent with that in gas phase. The free energies of each point in channel decrease, which was caused by the solvent effects. The solvent effects stabilize each species. The activating free energies in solution phase fall down, which was comparative to that in gas phase. The reaction proceeds easier and the activating free energies decrease more in the CC attacking channel.
    Potential Energy Surfaces and Potential Energy Well of Reaction NO3-+Cl2→ClONO2+Cl-
    CHI Shao-Ming1,2, WANG Ning1, MA Li-Ying1, FANG Fang2, TIAN Guo-Cai2, LI Guo-Bao2, XU Si-Chuan1*
    2008, 29(6):  1228-1233.  doi:
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    The reaction potential surfaces(PESes) for the ion-molecule reaction of NO3-+Cl2 → ClONO2+Cl- were calculated at the B3LYP/6-311+G(d) level in the mode of three dimensions. Three original three-dimensional PESes prove that in the reaction there are no transition state and energy barrier, but there exists a potential energy well. The depth of the potential energy well is -55.0 kJ/mol(relative to NO3- and Cl2 completely be separated) calculated with CCSD(T)/6-311+G(d)// B3LYP/6-311+G(d). At the bottom of the well, there is a compound called Potential Well Compound(PWC), existing stably with the help of the well. The calculated theoretical infrared spectra predict that the PWC would be examined in low temperature infrared spectra. Our work shows that at low temperatures(~180 K) the reaction is dominated by its thermal dynamics. When the temperature going up, the PWC decomposes through reaction of(O2NOClCl)- → NO3-+Cl2, dominated by its chemical dynamics. Our study indicates that ClONO2 with Cl- cannot produce Cl2 at low temperatures in the gas-phase reaction.
    TD-DFT Study on Electronic Structure and Spectrum Properties of 8-Hydroxyquinolinato Manganese Complex
    XIA Shu-Wei*, SHA Peng-Yan, YU Liang-Min, FAN Yu-Hua, BI Cai-Feng, YANG Li-Rong
    2008, 29(6):  1234-1238.  doi:
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    The structure and electronic properties of 8-hydroxyquinolinato manganese(Ⅲ) complex(MnQ3, Q=8-hydroxyquinolinato) were studied theoretically with density functional theory(DFT). The structure was optimized and the calculation results show that the manganese ion is coordinated with one nitrogen atom and one oxygen atom of 8-hydroxyquinolinato ligand. The average bond length of Mn—N is 0.2072 nm and that of Mn—O is 0.1887 nm, which were consistent with the crystallographic data. In addition, the molecular structure and electronic structural characteristics of the complex were analyzed. The contribution of Mn(Ⅲ) to the frontier molecular orbitals are significant, 28.53% to HOMO and 68.30% to LUMO. The electro-absorption spectrum of MnQ3 was calculated by time-dependent density functional theory, the calculated results show that the two strong absorption peaks are at 756.8 nm and 532.7 nm respectively due to the charge transformation from intra-ligand to manganese(Ⅲ). From two-molecule system, the charge was transported from one complex to the neighbor one. The intermolecular interaction affects the composition of the frontier molecular orbital obviously.
    Theoretical Studies on the Spectroscopic Properties of N,N'-Bis(salicylidene)-1,2-ethylenediaminePt(Ⅱ) Complexes
    ZHOU Xin1, MENG Xuan-Yu1, LI Ming-Xia2, PAN Qing-Jiang2, ZHANG Hong-Xing1*
    2008, 29(6):  1239-1242.  doi:
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    The electronic structures and spectroscopic properties of N,N'-bis(salicylidene)-1,2-ethylene-diamine(H2salen)Pt(Ⅱ) complexes were calculated with the DFT/Lanl2dz method owing to its potential application on the OLEDs. The calculation results were comparable with the experimental ones and can be used to predict some experimental phenomena. The calculation reveals that both the lowest-energy absorption and triplet phosphorescence arise from the mixed transitions of [L(Phenoxide lone pair)→π*(imine)](LLCT) and [Pt(5d)→π*(Schiff base)](MLCT). Furthermore, our calculations determined the triplet-excited geometrical structure for the complex, providing a straightforward view for experiment. No obvious solvatochromic effect was observed in the absorption and emission spectra in our calculation, indicating that the spectra wave-lengths are independent of the solvent polarity.
    Copolymerization and Modification of Biodegradable Poly(butylene succinate) by 1,4-CHDM
    ZHANG Min1,2*, LAI Shui-Li1, SONG Jie1, QIU Jian-Hui3
    2008, 29(6):  1243-1246.  doi:
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    Biodegradable poly(butylene-succinate)(PBS) was modified by intoducing 1,4-cyclohexanedimethylene(CHDM) with a stereo structure into the main chain. The results show that a copolymer with a high molecular weight Mn more than 100000 was obtained in 2 h. When 1,4-CHDM increased, the crystallinity decreased but Tg and tanδ increased and the internal friction peak width changed narrow gradually. The 1,4-CHDM content was 30%, the elongation ratio would reach 1232%. All the decomposition temperature of the polymer was above 300 ℃, with a good thermal stability.
    Preparation of Insect Sex Pheromone Simulacrum Dodecanol Containing Microcapsules via Complex Coacervation Method and Its Release Behavior
    GU Xiang-Ling1, ZHU Xiao-Li2, ZHANG Zhi-Guo2, TAN Ye-Bang1, KONG Xiang-Zheng1,2*, LIU Wei-Peng2
    2008, 29(6):  1247-1254.  doi:
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    Dodecanol(C12OH), as an insect sex pheromone simulacrum, was encapsulated via complex coa-cervation with gelatin(GE) and acacia gum(AG) as the wall materials and the release behavior of C12OH from microcapsules was investigated via varying solution concentration and crosslinking of wall materials. Firstly, the yeild of coacervation at different pH was tested when mass ratio of GE to AG was set at 1∶1. It was observed that, for the complex coacervation maximum yield was achieved at pH=4.0. Then properties of microcapsules and dispersions with different dispersants were detected. The results showed that with Tween 20/Span 80(mass ratio 1∶1) as dispersants, it improved the encapsulation efficiency of microcapsules and the stability of the dispersion. When the wall material mass fraction was equal to or higher than 3%, the size of the microcapsules was larger than that prepared with 2% wall material mass fraction and their C12OH loading and encapsulation rate were remarkably higher than the latter. In addition, increasing of crosslinker led to the capsules with much higher crosslinking, C12OH loading and encapsulation rates. Microcapsules crosslinked with formaldehyde had a lower crosslinking but a higher C12OH encapsulation rate compared with those crosslinked with glutaraldehyde at equal level. The structure of microcapsules was analyzed through scanning electronic microscopy with the conclusion that it did encapsulate C12OH in microcapsules. Moreover, to investigate C12OH release from the capsules, microcapsules were placed into an incubator with constant temperature(35 ℃) and relative humidity(50% RH), and taken out for C12OH examination by weighing the samples. It was found that microcapsules prepared with 3% and 4% mass fraction solution of wall materials, crosslinked with 1% glutaraldehyde manifested a controlled C12OH release behavior as well as thoses done with 5% wall materials solution and 1% glutaraldehyde. This work indicates that the release of C12OH can be well controlled by adjusting polymer concentration and crosslinking of microcapsules. This is of great importance for our on-going study on the controlled release of authentic insect semiochemicals.
    Real-time Monitoring the Residual Monomer in St/BA Emulsion Copolymerization
    GUO Long-Hai, YUAN Hong-Fu, QIU Teng, LI Xiao-Yu*
    2008, 29(6):  1255-1261.  doi:
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    The near-infrared(NIR) spectroscopy was used to monitor the residual monomer in the styrene/butyl acrylate emulsion copolymerization reaction. There were nine semi-batch styrene/n-butyl acrylate emulsion copolymerization reactions. The samples were gotten in line, and the NIR spectroscopy of the emulsion were measured at the same time. It was shown that the emulsion particles scattered the NIR and affected the result of analysis, through the pretreatment of Multiplicative Scatter Correction(MSC) to the spectra. The NIR data of emulsion was analyzed by the method of Principal Component Analysis(PCA). The calibration model was established with 72 samples of six reactors, and the model was validated with 36 samples of three reactors. The amount of emulsifier was variational in the nine reactors in order that the calibration model could adapt the amount of emulsifier. The result of the research is that the Standard Error of Prediction of the calibration models for St and BA were 0.08026 and 0.05305.
    Preparation of Controlled-release Microspheres Loading Protein Through Solid-in-oil-in-water Emulsion Method
    DU Qing1,2, HU Jun-Li1,2, HAN Ya-Dong1,2, CHEN Xue-Si1*, JING Xia-Bin1
    2008, 29(6):  1262-1266.  doi:
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    A novel solid-in-oil-in-water(S/O/W) emulsion method for drug controlled-release system was investigated in this paper. Bovine serum albumin(BSA) was used as the model drug. At first, the nanoparticles containing proteins were obtained by adsorbing BSA from the solution onto the surface of nano-scale SiO2. Then PLGA microspheres loading the solid nanoparticles were fabricated with the solid-in-oil-in-water emulsion method. Compared with the traditional water-in-oil-in-water double emulsion method, this new method has marked advantages, such as improving the percentage of drug in microspheres and the drug entrapment efficiency. More importantly, the activities of protein could be retained better.
    Investigation of Diblock Copolymers of Poly(ethylene glycol) Methyl Ether-block-Poly(ε-caprolactone) Using MALDI-TOF Mass Spectrometry Technique
    LU Xian-Feng1,2, LIU Zhi-Qiang1, Xing Jun-Peng1, LIU Shu-Ying1*
    2008, 29(6):  1267-1270.  doi:
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    Poly(ethylene glycol) methyl ether-block-poly(ε-caprolactone)(MPEG-b-PCL) was analyzed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF MS) combined with post-source decay(PSD) technique. The block length and block distribution of the diblock copolymer were clearly determined. The results indicate that MALDI-TOF MS combined with PSD is an excellent method for the study of structures of block copolymer. It provided an important evidence for realizing and applying the diblock copolymer. Furthermore, the analysis method of the diblock copolymer was established.
    Mittag-Leffler Function and Its Application to Viscoelastic Stress Relaxation
    CHEN Hong-Shan*, LI Ming-Ming, KANG Yong-Gang, ZHANG Su-Ling
    2008, 29(6):  1271-1275.  doi:
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    Functions of Mittag-Leffler(M-L) type play a special role in the fractional order viscoelastic theory. However, this function converges very slowly and it will likely result in divergence in numerical evaluation. The convergence criterion and the evaluation of M-L functions is discussed. When applying fractional Maxwell model to the stress relaxation, the parameters determined by using the asymptotic solutions of M-L functions are not correct to describe the relaxation process. A method combining genetic algorithm and conjugated gradient was proposed to optimize the model parameters. And the fractional Maxwell model based on the optimized parameters can be used to simulate viscoelastic relaxation process very well.
    Preparation of Antistatic and Flame Retarding Material by Polypropylene Composites Filled with Conductive Polyacenic Semiconductor Material
    LIN Lin, WANG Cun-Guo*, ZHANG Ping, YANG Lei, XIAO Hong-Jie, LI Bing-Hai, LI Da-Peng, ZHAO Qiang
    2008, 29(6):  1276-1281.  doi:
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    Nano-particles of polyacenic semiconductor material(PAS) were used as a novel filler instead of carbon black and graphite to prepare PAS/polypropylene(PP) composite, which has antistatic and flame retarding properties. The percolation threshold of PAS/PP composites was confirmed and the phenomenon of percolation threshold was investigated. The effects of content of PAS in the composite on volume resistivity and surface resistivity were discussed in detail. The result of resistivity test shows that the composites were in percolation threshold, when the mass fraction of PAS was between 16.7% and 28.6%. When the mass fraction was 28.6%, the volume resistivity decreased to 2.09×107 Ω·cm. In addition, flame-retarding property was studied too. Experimental result shows that PAS/PP composites could flame out after ignition in the air when the mass fraction of PAS was more than 23.1%.
    研究快报
    Influences of Phase Structure on Room Temperature Conductivity of Polyethylene Oxide/Succinonitrile/Lithium Perchlorate Composite Electrolytes
    YUE Rui-Juan1,2, NIU Yan-Hua1, WANG Zhi-Gang1*
    2008, 29(6):  1282-1284.  doi:
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    The polyethylene oxide/succinonitrile/lithium perchlorate(PEO/SN/LiClO4) composite electrolytes with different PEO/SN molar ratios were prepared and their room temperature(RT) ionic conductivities were detected. The influences of phase structure and morphology on ionic conductivity of composite electrolytes were characterized via wide-angle X-ray diffraction and polarized optical microscopy. The results show that with addition of PEO, the spherulitic morphology for plastic crystal phase of SN gradually disappears and the liquid phase of SN as a plasticizer role to PEO starts to appear, which is beneficial to the enhancement of RT ionic conductivity, thus the PEO/SN/LiClO4(molar ratio 50/45/5) sample shows the highest RT ionic conductivity of 1.5×10-3 S/cm. With PEO molar fraction above 50%, the RT ionic conductivity of composite electrolytes decreases due to increasing crystallinity of PEO.
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