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A thin-layer spectroelectrochemical study of 3.3.,5,5'-tetramethylbenzidine at SnO_2.F film optically transparent electrode

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Science china chemistry 2004年第4期47卷 267-275页

作者： JIAO Kui1, YANG Tao2.& NIU Shuyan1,2.1. college of {3. and {2. {3., Qingdao university of Science and Technology, Qingdao 2.6042. china 2. college of {3. and Chemical {3., Ocean university of china, Qingdao 2.6003. china Correspondence should be addressed to Jiao Kui 1. college of chemistry and {2.{3. Qingdao University of Science and Technology 266042 Qingdao China 2. college of chemistry and Chemical {2. Ocean University of China 266003 Qingdao China

The electrooxidation of 3.3.,5,5′-tetramethylbenzidine (TMB) is dependent on the pH value of Britton-Robinson (B-R) buffer solution. In this work, the electrooxidation behavior of TMB was investigated with a SnO2.F film optically transparent thin-layer spectroelectrochemical cell. TMB underwent one two-electron electrooxidation process in the pH range from 2.0 to < 4.0, and two successive one-electron electrooxidation processes in the pH range from 4.0 to < 7.0 in the B-R buffer solution. At pH 6.5, the electrooxidative product of TMB generated a subsequent chemical reaction to yield an azo compound. Several spectroelectrochemical techniques, such as thin-layer cyclic voltammetry, thin-layer cyclic voltabsorptometry, thin-layer potential-controlled electrolysis absorptometry, thin-layer single-potential-step chronoabsorptometry, thin-layer dou-ble-potential-step chronoabsorptometry, thin-layer single-potential-step open-circuit relaxation chronoabsorptometry, were applied to this investigation. The formal potential E0’ and the electron transfer number corresponding to the electrooxidation of TMB in B-R buffer solution, and the reaction rate constant of the subsequent chemical reaction were determined.

关键词： 3.3.,5,5′-tetramethylbenzidine tin oxide film optically transparent electrode thin-layer spectroelectro-chemistry electrooxidation

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Antiviral compounds and one new iridoid glycoside from Cornus officinalis

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Progress in Natural Science:Materials International 2006年第2期16卷 142-146页

作者： WANG Yue, LI Zhengquan, CHEN Lirong and XU Xiaojie (college of chemistry and {2.{3., peking university, Beijing 100871, china) [a]college of chemistry and {2.{3. Piking University Beijing China

From Cornus officinalis Sieb. et Zucc., bioassay-guided fractionation led to the isolation of four active tannin compounds with high effectiveness of inhibiting Hepatitis C virus NS3.serine protease in vitro. The compounds are: 1,2.3. 6-tetragalloyl-β-D-glucopyranose (1), 1,2.3.4,6- pentagalloyl-β-D-glucopyranose (2., Tellimagrandin I (3. and Tellimagrandin II(4). The four compounds could inhibit HCV NS3.protease in vitro with IC50 values of 6.98, 5.11, 7.0 and 4.8μmol/L respectively. In addition, a new iridoid glycoside (5) was also isolated from Cornus officinalis Sieb. et Zucc., which was assigned to be 7-O-butyl morroniside by spec-troscopic analysis.

关键词： inhibitor HCV NS3.protease iridoid glycoside Cornus officinalis Sieb. et Zucc.

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Synthesis,Structure and Antitumor Activities of Tridccapeptide PSPP3.from Papaver Somniferum Pollen

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Chinese Chemical Letters 1999年第2期10卷 115-116页

作者： Jia Xi XU Sheng JIN(college of chemistry and {2.{3., peking university, Beijing 100871) Coll. of Chem. and Molec. Eng. Peking University Beijing 100871 China

Five analogs and five segments of the Papavor Somniferum pollen tridecapeptidePSPP3.were designed and synthesized by using solid-phase peptide synthesis method. Theirinhibitive activities to human liver tumor cell Bel-7402.were assayed by MTT method and theirsecondary structures in solution were determined by CD spectra. The relationship of the structureand activity was discussed.

关键词： Pollen peptide anti-tumor activity structure and activity

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A NOVEL PHOTO-INITIATING SYSTEM FOR ATOM TRANSFER RADICAL POLYMERIZATION OF STYRENE

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Chinese Journal of Polymer Science 2001年第5期19卷 441-445页

作者： Shu-hui Qin Dong-qi Qin Kun-yuan Qiu Department of Polymer Science and engineering college of {2. and{3. engineering peking university Beijing 100871, china Beijing Univ Dept Polymer Sci & Engn Coll Chem & Mol Engn Beijing 100871 Peoples R China

A novel photo-induced initiating system, 2.2.dimethoxy-2.phenylacetophenone (DMPA)/ferric tri(NN-diethyldithiocarbamate) [Fe(DC)(3.], was developed and used for the atom transfer radical polymerization (ATRP) of styrene in toluene. The polymerization proceeds with DMPA as photo-initiator, Fe(DC)(3. as catalyst and DC as a reversible transfer group, while the halogen and ligands are free. Well-defined PSt was prepared and the polymerization mechanism revealed by end group analysis belongs to a reverse ATRP. Block copolymer was prepared by using thus obtained PSt as macroinitiator and Fe(DC)(2. as catalyst under UV light irradiation via a conventional ATRP process.

关键词： photo atom transfer radical polymerization living radical polymerization well-defined polystyrene block copolymer

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Systematic study of the transfer of amino acids across the water/1,2.dichloroethane interface facilitated by dibenzo-18-crown-6

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Science china chemistry 2004年第1期47卷 24-33页

作者： CHEN Yong, YUAN Yi, ZHANG Meiqin, LI Fei, SUN Peng, GAO Zhao & SHAO YuanhuaState Key Laboratory of Electroanalytical chemistry, Changchun Institute of Applied chemistry, Chinese Academy of Sciences, Changchun 13.02.,{2. college of chemistry and molecular engineering, peking university, Beijing 100871,{2. Lab. of Electroanalytical Chem. Changchun Inst. of Appl. Chem. Chinese Acad. of Sci. Changchun 130022 China Coll. of Chem. and molecular Eng. Peking Univ. Beijing 100871 China

Facilitated ion transfer reactions of 2. amino acids with dibenzo-18-crown-6 (DB18C6) at the water/1,2.dichloroethane (W/DCE) interfaces supported at the tips of micro- and nano-pipets were investigated systematically using cyclic voltammetry. It was found that there were only 10 amino acids, that is, Leu, Val, lie, Phe, Trp, Met, Ala, Gly, Cys, Gin (in brief), whose protonated forms as cations can give well-defined facilitated ion transfer voltammograms within the potential window, and the reaction pathway was proven to be consistent with the transfer by interfacial complexation/dissociation (TIC/TID) mechanisms. The association constants of DB 18C6 with different amino acids in the DCE (β0), and the kinetic parameters of reaction were evaluated based on the steady-state voltammetry of micro- or nano-pipets, respectively. The experimental results demonstrated that the selectivity of complexation of protonated amino acid by DB18C6 compared with that of alkali metal cations was low, which can be attributed to the vicinal effect arising from steric hindrance introduced by their side group and the steric bulk effect by lipophilic stabilization. Moreover, the association constants and the standard rate constants for different amino acids showed good correlations with their hydrophobicity (π), except Gly and Met, which inferred that the selectivity of such heterogeneous complex reaction for different amino acids with DB18C6, was not only affected by discrimination in binding these ions to the crown ether macro-cycle, but also significantly modified by the ion transfer Gibbs energy which was closely related to the structure of the transferred ions, protonated amino acids.

关键词： micro-/nano-pipet, water/1,2.dichloroethane interface, facilitated ion transfer, cyclic voltammetry, amino acid.

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SYNTHESIS AND CHARACTERIZATION OF A NOVEL BLUE LIGHT EMITTING ROD-COIL DIBLOCK OLIGOMER

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Chinese Journal of Polymer Science 2002年第5期20卷 401-407页

作者： Lifang Yang Haifeng He Hongqing Cao Xinhua Wan Qi-feng Zhou Department of Polymer Science & engineering college of {2. &{3. engineering peking university Beijing 100871, china peking Univ Coll Chem & Mol Engn Dept Polymer Sci & Engn Beijing 100871 Peoples R China

Four new rod-coil diblock molecules, which had well-defined para-phenylene oligomers (PPP, from biphenyl to quinquephenyl) as rigid segments and poly(ethylene oxide) (PEO, M-w ca. 750) as flexible segments, were synthesized. The chemical structure and the number of repeating unit in PEO coil and PPP rod were characterized by H-1-NMR and MALDI-TOF mass spectrometry. The diblock oligomers showed good solubility in common organic solvents and aggregated in water as characterized by a blue shift in UV-vis absorption spectra, a red shift in emission spectra, quenching of the fluorescence and formation of the microfibrilla and fractal-like structures. The formation of different supramolecular structures meant that this effort might lead to commercial important highly organized functional materials.

关键词： rod-coil diblock oligomer MALDI-TOF mass spectrometry microfibrilla aggregate fractal-like pattern

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Syntheses,characterization,crystal structure and magnetic properties of copper(Ⅱ) α,β-unsaturated carboxylate complexes with trimethyl phosphate

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Chinese Science Bulletin 2001年第12期46卷 987-991页

作者： WANG Yaoyu, LIU Ping, SHI Qian, GAO Yici & SHI Qizhen1. Department of chemistry, Northwest university, Xi’an 710069,{2. 2. Department of chemistry, Wenzhou Teachers college, Wenzhou 3.2}003.{2. 3. Department of chemistry, Lanzhou university, Lanzhou 73.000,{2. Department of chemistry Northwest University Xi’an China Department of chemistry Wenzhou Teachers College Wenzhou China Department of chemistry Lanzhou University Lanzhou China

Two ternary complexes Cu2.4[OP(OCH3.3.2.(A represents CH2.CH-COO- and CH2.C(CH3.-COO-) have been synthesized, and elemental analyses, IR, ESR, electronic reflectance spectra and magnetic studies were carried out. The single crystal X-ray diffraction shows that Cu2.CH2.C(CH3.-COO]4[OP(OCH3.3.2.is triclinic, with space group P1, a = 1.0512.(13., b = 1.7559(5), c = 1.94479(3. nm, α =91.2.3.14)°,(β = 102.559(6)°,γ= 106.3.9(13.°, Z = 4 and R = 0.0668. Two copper(Ⅱ) atoms are bridged by four (a-methacrylate groups, and each copper(Ⅱ) atom is coordinated with a trimethyl phosphate molecule in the axial position, forming a distorted square pyramidal configuration. The symmetric center is between the two copper(Ⅱ) atoms, and the Cu-Cu bond distance is 0.2.098(6) nm. The Cu-Cu distance and magnetic studies suggest that there exist anti-ferromagnetic interactions between the two copper(Ⅱ) atoms.

关键词： copper(Ⅱ ) complex α β-unsaturated carboxylate trimethyl phosphate magnetic property crystal structure.

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Reinvestigation on the Reaction of Salicylic Chloride with Salicylic Amide and X-ray Crystal Structure of a New Macrocyclic Polyester

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Chinese Journal of Structural chemistry 2003年第5期22卷 512-516页

作者： DU Da-Ming② CHEN Xiao HUA Wen-Ting JIN Xiang-Lin (Key Laboratory of Bioorganic chemistry and molecular {2. of Ministry of Education,{3. of chemistry and molecular {2., peking university, Beijing 100871, china) Key Laboratory of Bioorganic chemistry and molecular {2. of Ministry of Education College of Chemistry and Molecular Engineering Peking University

The reaction of salicylic chloride and salicylic amide at 170 ℃ gave benzoxazine and a new macrocyclic polyester 3. whose crystal structure has been determined by single-crystal X-ray diffraction analysis. Compound 3. C2.H16O8, Mr = 480.41, monoclinic, space group P2./n, a = 15.3.3.3., b = 14.196(3., c = 2..147(4) ? b = 103.3.0}3., V = 4485(2. ?, Z = 8, F(000) = 1984, Dc = 1.42. g/cm3.and m = 0.106 mm-1. The final R = 0.053. and wR = 0.12.5 for 7903.observed reflections (I ≥ 2.I)). In the asymmetric unit of the compound there exist two independent molecules which are connected by weak aromatic CH…O hydrogen bonding between C(47)?H(47) and atom O(7) of the carbonyl group.

关键词： salicylic chloride salicylic amide polyester macrocycle crystal structure

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Investigation on Vibrational Spectra and Structures of 4-Mercaptopyridine Monomer and Its Dihydrate

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Chemical Research in Chinese Universities 2006年第1期22卷 90-93页

作者： CHENG Jian-bo 1,2., XUE Wei-qing 1 , ZHAO Bing 1** , ZHANG Gang 3.and GONG Bao-an 2.1. Key Laboratory for Supramolecular Structure and Material of Ministry of Education, Jilin {3., Changchun 13.012. P. R.{2. 2. Science and {3. college of chemistry and Biology, Yantai {3., Yantai 2.4005, P. R.{2. 3. State Key Laboratory of Theoretical and Computational chemistry, Jilin {3., Changchun 13.02., P. R.{2. [a]Key Laboratory for Supramolecular Structure and Material of Ministry of Education Jiln University Changchun 130012 P. R. China[b]Science and Engineering College of Chemistry and Biology Yantai University Yantai 264005 P. R. China[c]State Key Laboratory of Theoretical and Computational Chemistry Jiln University Changchun 130023 P. R. China

The optimized molecular structures and vibrational frequencies of 4-mercaptopyridine(4MPY) monomer and its dihydrate were studied by means of the density functional theory(DFT), viz. B3.YP method with the 6-3.1++G(d,p) basis set. On the basis of the calculations, the assignments of the vibrational spectra of the monomer and the dihydrate were performed, and so were investigated the changes in the structure and the vibrational spectrum of the dihydrate as well as the intermolecular force resulting in the formation of the dihydrate. The calculated results show that each of the water molecule planes is vertical to the pyridine ring plane in the dihydrate that is formed via the H-bonds between 4MPY and water molecules. Furthermore, the structure and the vibrational spectrum of 4MPY can be consi- derably affected by the water molecules.

关键词： 4MPY Dihydrate Vibrational spectra DFT molecular structure

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Biotic communities of the marine ecosystem in Meizhou Bay

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Journal of Environmental Sciences 1996年第1期8卷 48-56页

作者： Ren Jiuchang Cai Xiaoming (Center of Environmental Sciences,peking university, Beijing 100871,{2.)Chen Bin({3. of Life Sciences, peking university, Beijing 100871, china )Li Peng({3. of chemistry and molecular engineering, peking university, Bei Ctr of Envmtl Sci Peking Univ Beijing China China

The current situation of biotic communities in Meizhou Bay is presented in this *** species composition,seasonal variation,and distribution of phytoplankton,zooplankton, red tide organisms,fishes,and benthos in Meizhou Bay were investigated,and the content of chlorophyll a and primary production and their seasonal variation were also *** water quality of Meizhou Bay was monitored by measuring the density of Escherichia coli. Results reveal that there is a great variety of species in Meizhou Bay and the water in Meizhou Bay is *** the individual numbers of various organisms are very low, especially those of ***,there are more than 40 species of red tide organisms and there exist opportunities of red tides between May and *** these demand cautious be taken in the future development of this area although it has great environment capacity.

关键词： biotic community marine ecosystem Meizhou Bay.

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