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An efficient chiral synthesis of (R)-N-[3-acetyl-4-(2-hydroxy-3-isopropylamino-propoxy)phenyl]-butanamide with high enantioselectivity

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Science china chemistry 2009年第8期52卷 1216-1219页

作者： WANG NaiXing1,2 & TANG XinLiang1,3 1 Technical Institute of Physics and chemistry,Chinese Academy of Sciences,Beijing 100080,china 2 College of chemistry and chemical engineering,Graduate university of Chinese Academy of Sciences,Beijing 100049,china 3 school of chemical engineering and Environment,Beijing Institute of Technology,Beijing 100081,china 1. Technical Institute of Physics and chemistry Chinese Academy of Sciences Beijing 100080 China 2. College of chemistry and chemical engineering Graduate University of Chinese Academy of Sciences Beijing 100049 China 3. school of chemical engineering and Environment Beijing Institute of Technology Beijing 100081 China

R-Enantiomer of the β-receptor antagonist N-[3-acetyl-4-(2-hydroxy-3-isopropylamino-propoxy)phenyl] butanamide with high enantioselectivity was synthesized from cheap starting materials and enantiopure chiral reagent through an efficient,convenient and practical synthetic *** product was detected by 1H NMR,13C NMR,and MS,and the enatiomeric excess was determined by chiral HPLC analysis using a chiracel AD-H column.

关键词： chiral synthesis enantioselectivity enatiomeric excess chiral HPLC analysis

Novel nanoporous binary Ag-Ni electrocatalysts for hydrazine oxidation

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Rare Metals 2010年第1期29卷 26-31页

作者： YI Qingfeng, LI Lei, YU Wenqiang, LIU Xiaoping, ZHOU Zhihua, and NIE Huidong school of chemistry and chemical engineering, Hunan university of Science and Technology, Xiangtan 411201, china school of chemistry and chemical engineering Hunan University of Science and Technology

From an aqueous mixture of Ag（I）-EDTA complex and Ni（II） nitrate, silver and nickel particles were co-deposited on the surface of titanium substrates by the hydrothermal method using hydrazine hydrate as a reduction agent. The prepared titanium-supported nano-scale Ag and Ag-Ni particles （nano Ag/Ti, nano Ag86Ni14/Ti, nano Ag77Ni23/Ti, and nano Ag74Ni26/Ti） exhibit nanoporous 3D network textures. Their electrocatalytic activity towards hydrazine oxidation in alkaline solutions was evaluated by cyclic voltammetry and chronoamperometry. The results show that the four samples present a low onset potential of ca. -0.60 V vs. SCE and considerably high and stable anodic current densities for hydrazine oxidation. Among them, the nano Ag86Ni14/Ti electrode exhibits the highest anodic current density towards hydrazine oxidation, showing an increment of electro-active sites on the nano Ag86Ni14/Ti due to the addition of Ni to Ag particles.

关键词： electrocatalyst silver hydrazine oxidation fuel cell

Study on interaction between macrocell and microcell in the early corrosion process of reinforcing steel in concrete

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Science china(Technological Sciences) 2010年第5期53卷 1285-1289页

作者： LI LanQiang1,DONG ShiGang1,WANG Wei2,HU RongGang1,DU RongGui1,LIN ChangJian1,ZHUO XiangDong1 & WANG Jia2 1 State Key Laboratory of Physical chemistry of Solid Surfaces,Department of chemistry,College of chemistry and chemical engineering,Xiamen university,Xiamen 361005,china 2 College of chemistry and chemical engineering,Ocean university of china,Qingdao 266100,china 1. State Key Laboratory of Physical chemistry of Solid Surfaces Department of Chemistry College of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China2. College of Chemistry and Chemical Engineering Ocean University of China Qingdao 266100 China

An array electrode technique was developed as a novel electrochemical method for studying the interaction between macrocell and microcell in the early corrosion process of reinforcing steel in cement *** corrosion potential and galvanic current of macrocell corrosion of the reinforcing steel in cement mortar were imaged by the array electrode technique during the corrosion initiation and *** was certified that the corrosion macrocell current is closely related with the difference of corrosion potential between the anodic and cathodic *** corrosion macrocell and microcell always exist during the corrosion *** interaction of corrosion macrocell and corrosion microcell of steel in concrete was directly sensed by the array electrode for the first time,and was discussed in terms of corrosion electrochemistry.

关键词： reinforcing steel in concrete array electrode macrocell microcell

Supporting of Nickel(Ⅱ) Acenaphthenediimine with Free Amino Group for Ethylene Polymerization

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Journal of Wuhan university of Technology(Materials Science) 2010年第2期25卷 260-264页

作者：胡扬剑 Department of chemistry and chemical engineering Huaihua College

Bis （4-（4-amino-3, 5-diethylbenzyl）-2, 6-diethylphenylimino） acenaphthene] di- chloronickel （NiLCl2） was prepared and supported on SiO2 modified by methyl trichlorsilane（S-1） and on SiO2-MgCl2/TiCl4 （S-2） respectively. Two supported catalysts S-1 and S-2 used as catalysts for ethylene polymerization were studied and the influences of various polymerization conditions, including the polymerization temperature, cocatalysts, Al/Ni molar ratio on the catalytic activity, branching degree and branch length of PE were also investigated. The experimental results show that the supported catalysts exhibit higher catalytic activity for ethylene polymerization, the highest catalytic activity of S-1 using AlEt2Cl as cocatalyst at 50 ℃, reaching 5.8×10^5gPE/molNi·h, and needed lower Al/Ni molar ratio compared to homogeneous analogue.

关键词： nickel diimine complex supported catalyst branched polyethylene diethylaluminium chloride

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 chemistry and Molecular engineering, Qingdao university of Science and Technology, Qingdao 266042, china 2. College of chemistry and chemical engineering, Ocean university of china, Qingdao 266003, china Correspondence should be addressed to Jiao Kui 1. College of chemistry and Molecular engineering Qingdao University of Science and Technology 266042 Qingdao China 2. College of chemistry and chemical engineering 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 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

Resolution of α-cyclohexyl-mandelic acid enantiomers by two-phase (O/W) recognition chiral extraction

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Science china chemistry 2007年第6期50卷 764-769页

作者： TANG KeWen1,2, ZHANG GuoLi2, HUANG KeLong2, LI Yuanjian3 & YI JianMin1,2 1 Department of chemistry and chemical engineering, Hunan Institute of Science and Technology, Yueyang 414000, china 2 College of chemistry and chemical engineering, Central South university, Changsha 410083, china 3 College of Pharmaceutical Science, Central South university, Changsha 410078, china Department of chemistry and chemical engineering Hunan Institute of Science and TechnologyYueyang 414000China College of chemistry and chemical engineering Central South UniversityChangsha 410083China

This paper presents a new chiral separation technology:two-phase(O/W)recognition chiral *** behavior of alpha-cyclohexyl-mandelic acid enantiomers was studied in the extraction system with D(L)-isobutyl tartrate in 1,2-dichloroethane organic phase and beta-CD derivatives in aqueous phase,and the influence of the kind and concentration of extractant and pH on extraction performance was *** experimental results indicate that two-phase(O/W)recognition chiral extraction is of strong chiral separation ***-^-CD,HE-beta-CD and Me-beta-CD have higher recognition ability for S-CHMA than that for R-CHMA,among which HP-beta-CD has the strongest ability;whereas,D-isobutyl tartrate has reversed recognition ability for *** the extraction system containing HP-beta-CD and D-isobutyl tartrate,e.e.% of S-CHMA in aqueous phase reached 27.6% by one stage extraction,and the distribution ratio for R-CHMA(k_R)and for S-CHMA(k_S)and separation factor(alpha)are 2.44,0.89 and 2.49,***,pH and concentration of extractant have great effects on chiral separation ***-phase(O/W)recognition chiral extraction has great significance for preparative separation of racemic compounds.

关键词： two-phase(W/0)recognition chiral extraction alpha-cyclohexyl-mandelic acid enantiomers

Sensing characterization of Sn/In/Ti nanocomplex oxides for CO, CH_4 and NO_2

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Science china(Technological Sciences) 2007年第1期50卷 18-26页

作者： BAI ShouLi1, TONG ZhangFa2, LI DianQing1, HUANG XiaoWei3, LUO RuiXian1 & CHEN AiFan1 1 State Key Laboratory of chemical Resource engineering, Beijing university of chemical Technology, Beijing 100029, china 2.school of chemistry and chemical engineering, Guangxi university, Nanning 530004, china 3 College of Biochemical engineering, Beijing Union university, Beijing 100023, china 1. State Key Laboratory of chemical Resource engineering Beijing University of Chemical Technology Beijing 100029 China 2. school of chemistry and chemical engineering Guangxi University Nanning 530004 China 3. College of Biochemical engineering Beijing Union University Beijing 100023 China

The nanocomplex oxides of Sn-In and Sn-In-Ti were prepared by controlled co-precipitation method as sensing materials of semiconductor gas sensors for detection of CO, CH4 and NO2. Through manipulating the Sn/In cation ratio, metal salt total concentration, precipitation pH value and aging time, the nanocrystalline powders were successfully derived with chemical homogeneity and superior thermal stability, compared with the single component oxides. The particle size and morphology, surface area, and thermal and phase stabilities were characterized using TEM, TG-DTA, BET and XRD. The sensing tests showed that the Sn-In com-posites exhibit high sensitivity and selectivity for CO and NO2. The introduction of TiO2 enhanced CH4 sensitivity and selectivity, particularly, additives of Pd and Al2O3 as a dopant and surface modification greatly enhanced the sensing properties. The sensitivity depended on the composition of composites, calcination temperature and operating temperature. The optimal values were (25%In2O3- 75%SnO2)-20%TiO2 for ternary composite, 600 and 300℃, respectively. Temperature-programmed de-sorption (TPD) studies were employed to explain the gas adsorption behavior dis-played by the surface of nanocomposites and X-ray photoelectron spectroscopic (XPS) analysis was used to confirm the electronic interactions existing between oxide components. The sensing mechanism of the nanocomposites was attributed to chemical and electronic synergistic effects.

关键词： SnO2-In2O3-TiO2 nanocomposites CO NO2 CH4 gas sensing

Reversible folding/unfolding of small α-helix in explicit solvent investigated by ABEEMσπ/MM

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Science china chemistry 2009年第11期52卷 1917-1924页

作者： LIU Cui & YANG ZhongZhi chemistry and chemical engineering Faculty,Liaoning Normal university,Dalian 116029,china chemistry and chemical engineering Faculty Liaoning Normal University Dalian China

We have performed molecular dynamics simulations on the reversible folding/unfolding of small α-helix(short Ala based peptide Ala5) in explicit water solvent in terms of ABEEMσπ/MM.A dynamics analysis shows that the α-helical turn can be preserved up to a period of about 2 ns at 300 K,which supports the conclusions of Margulis et *** time trajectory of the root mean square deviation between the heavy atoms of the backbone and the helical reference structure indicate that "helix melting and formation occurs rapidly on a time scale of 0.1 ns at 300 K" is not a felicitous *** first quantificationally concluded that the helix nucleation can maintain 2 ns,1―1.5 ns and 0.8 ns for Ala5 at 300 K,400 K and 500 K,***,increasing temperature dose not alter the pathway of folding/unfolding,but change the *** analysis of structures in a "transition-state ensemble" shows that helix-to-coil transitions occurs predominantly through breaking of hydrogen bonds at the helix ends(92%),particularly at the C-terminus(50%).Hydrogen bonds' breaking and formation occurs on a time scale of 0.1 ns.

关键词： reversible folding/unfolding of protein Ala5 temperature hydrogen bond

FINITE ELEMENT METHOD AND ANALYSIS FOR chemical-FLOODING SIMULATION

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Systems Science and Mathematical Sciences 2000年第3期13卷 302-308页

作者： YUAN Yirang(Institute of Mathematics, shandong university, jinan 250100, china) 山东大学数学所山东济南 250100

This article discusses the enhanced oil recovery numerical simulation of the chemical-flooding (such as surfactallts, alcohol, polymers) composed of three-dimensional multicomponent, multiphase and incompressible mixed fluids. The mathematical model can be described as a coupled system of nonlinear partial differential equations with initialboundary value problerns. viom the actual conditions such as the effect of cross interference and the three-dimensional charederistic of large-scale science-engineering computation,this article puts forward a kind of characteristic finite element fractional step schemes and obtain the optimal order error estdriates in L2 norm. Thus we have thoroughly solved the well-known theoretical problem proppsed by a famous scientist, R. E. Ewing.

关键词： chemical-flooding cross interference 3-dimensional fractional steps characteristic finite element method L^2 error estimates