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Photocatalytic degradation of carbofuran in TiO_2 aqueous solution: Kinetics using design of experiments and mechanism by HPLC/MS/MS

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Journal of Environmental Sciences 2013年第8期25卷 1680-1686页

作者： Hai Yang Shuolin Zhou Huajie Liu Weiwei Yan Liping Yang Bing Yi College of chemistry and Chemical Engineering Hunan Institute of Engineering College of chemistry and Chemical Engineering Hunan Normal University South China institute of Environmental Sciences Ministry of Environmental Protection

The photocatalytic degradation kinetics of carbofuran was optimized by central composite design based on response surface methodology for the first time. Three variables, TiO2 concentration, initial pH value and the concentration of carbofuran, were selected to determine the dependence of degradation efficiencies on independent variables. Response surface methodology modeling results indicated that the degradation efficiency of carbofuran was highly affected by the initial pH value and the concentration of carbofuran. Then nine degradation intermediates were detected by HPLC/MS/MS. The Frontier Electron Densities of carbofuran were calculated to predict the active sites on carbofuran attacked by hydroxyl radicals and photoholes. Point charges were used to elucidate the chemisorption pattern on TiO2 catalysts during the photocatalytic process. By combining the experimental results and calculation data, the photocatalytic degradation pathways of carbofuran were proposed, including the addition of hydroxyl radicals and the cleavage of the carbamate side chain.

关键词： carbofuran photocatalytic degradation central composite design kinetics mechanism

[Cd(bpy)(tp)(H_2O)]_n: An Interesting Brickwall-like Supramolecular Array Assembled by Intermolecular Interaction

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Chinese Journal of Structural chemistry 2009年第11期28卷 1480-1484页

作者：王小莉杨国栋戴劲草 institute of Materials Physical chemistry Huaqiao University

The polymeric solid, [Cu（bpy）（tp）（H2O）]n 1 （tp = terephthalate, bpy = 2,2＇-bipyridine）, has been obtained from the hydrothermal approach and characterized by X-ray diffraction, elemental analysis, IR spectra and thermogravimetric analysis. Compound 1 crystallizes in triclinic, space group P1 with a = 9.360（2）, b = 9.872（2）, c = 10.774（2）A, α = 106.281（5）, β = 112.471（5）, γ = 96.697（3）°, V = 854.5（3）A^3, Z = 2, GOF = 1.09, R = 0.0318 and wR = 0.0845. X-ray single-crystal analysis reveals that 1 is an interesting 3D staggered brickwall-like supramolecular array assembled through aromatic π-π stacking and hydrogen bonding interactions of 1D infinite zigzag polymeric chains.

关键词： coordination polymer hydrothermal synthesis supramolecular array hydrogen bond aromatic π-π stacking

INFLUENCE OF THE SOLVENT SWELLING ON MACROMOLECULAR CHOLESTERIC LIQUID CRYSTALLINE STRUCTURE

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Chinese Journal of Polymer Science 1999年第6期17卷 607-610页

作者：黄勇 Laboratory of Cellulose & Lignocellulosics chemistry Guangzhou Institute of Chemistry Chinese Academy of Sciences Guangzhou 510650 China

Ethyl-cyanoethyl cellulose [(E-CE)C]/cross-linked polyacrylic acid [PAA] molecular composites with cholesteric order were prepared. It was found that the macromolecular cholesteric structure was changed with the swelling of PAA in the composites. The selective reflection of the cholesteric phase shifted to the longer wavelength and the X-ray diffraction angle shifted to the high angle direction during swelling, which suggested that the cholesteric pitch and the number of the layers of ordered (E-CE)C chains in the cholesteric phase were increased.

关键词： cholesteic liquid crystal molecular composite ethyl-cyanoethyl cellulose in situ polymerization structure

Highly selective two-photon fluorescent probe for imaging of nitric oxide in living cells

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Chinese Chemical Letters 2014年第1期25卷 19-23页

作者： Qing Liu Lin Xue Dong-Jian Zhu Guo-Ping Li Hua Jiang Beijing national Laboratory for Molecular Sciences CAS Key Laboratory of PhotochemistryInstitute of ChemistryChinese Academy of Sciences University of Chinese Academy of Sciences College of chemistry Beijing Normal University

A new two-photon fluorescent probe, ADNO, for nitric oxide （NO） based on intramolecular photoinduced electron transfer （PET） mechanism d/splays a rapid response to NO with a remarkable fluorescent enhancement in PBS buffer. The excellent chemoselectivity of ADNO for NO over other ROS/RNS （reactive oxygen species or nitrogen species） and common metal ions was observed. Moreover, ADNO has been successfully applied in fluorescence imaging of NO of living cells using both one-photon microscopy （OPM） and two-~hoton microscopy （TPM）,

关键词： Fluorescent probe Nitric oxide Fluorescence imaging One-photon microscopy Two-photon microscopy

Synthesis of Hydroxypropyl-β-cyclodextrin Bonded Silica-gel and its Application to Resolution

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Chinese Chemical Letters 2006年第12期17卷 1547-1550页

作者： Jin Gang YU Ke Long HUANG Du Shu HUANG Jin Yue PU institute of Functional Material and chemistry College of Chemistry and Chemical Engineering Central South University Changsha 410083

In order to set up a simple and effective method for resolution of optical isomers, hydroxypropyl-β-cyclodextrin was bonded to silica-gel, which can be used for preparation of thin-layer chromatography plates. Resolution of clenbuterol and propranolol were investigated on these thin-layer chromatography plates using different combinations of solvent systems at ambient temperature. The best simultaneous resolution was achieved in solvent system of acetonitrilen-butanol （50：50, v/v）. Rst values of resolution of clenbuterol hydrochloride and propranolol hydrochloride are 3.6 and 4.3, respectively. The spots of different enantiomers are separated clearly. The results showed that hydroxypropyl-β-cyclodextrin bonded silica-gel could be successful in resolution of chiral adrenergic drugs. The study offers a direct, rapid and reliable method for separation of this kind of optically active compounds.

关键词： Hydroxypropyl-β-cyclodextrin bonded silica gel synthesis resolution chiral enantiomers.

A new immobilized cell method, silicone-immobilized cells used in preparation of chiral intermediates

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Progress in Natural Science:Materials International 1996年第4期 48-53页

作者：潘冰峰戴学倩李祖义 China Chinese Academy of Sciences Shanghai 200032 Shanghai institute of organic chemistry State Key Laboratory of Bioorganic and Natural Products chemistry

The silicone-immobilized Geotrichum sp. G38 was used in the reduction of benzil to (S)-benzoin. The effects of stannous octanoate content, ethyl silicate content, water content and entrapped cell mass on the activity of the immobilized cells were studied. The optimum pH value and temperature of the reaction medium were 7.0, 35℃ (free cells) and 40℃ (immobilized cells), respectively. The immobilized cells showed higher activity than free cells under optimum conditions. The extent of conversion remained greater than 90% when the immobilized cells were recycled 28 times.

关键词： silicone rubber Geotrichum sp. G38 immobilized cells biotransformation.

Major Mid-Late Holocene Cooling in the East China Sea Revealed by an Alkenone Sea Surface Temperature Record

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Journal of Ocean University of China 2014年第6期13卷 935-940页

作者： ZHAO Meixun DING Ling XING Lei QIAO Shuqing YANG Zuosheng Key Laboratory of Marine chemistry Theory and Technology Ministry of EducationOcean University of China institute of Marine organic Geochemistry Ocean University of China Key Laboratory of Marine Sedimentology and Environmental Geology First Institute of Oceanography State Oceanic Administration College of Marine Geoscience Ocean University of China

Although the mid-late Holocene cold and dry event about 4000years ago （the 4ka event） has been observed almost globally, it was most prominent in terrestrial climate proxies from the lower latitudes. Here we evaluate the oceanic response to this event in terms of a Holocene sea surface temperature （SST） record reconstructed using the U^7 index for Core B3 on the continen- tal shelf of the East China Sea. The record reveals a large temperature drop of about 5~C from the mid-Holocene （24.7~C at 5.6ka） to the 4ka event （19.2~C at 3.8ka）. This mid-late Holocene cooling period in Core B3 correlated with （i） decreases in the East Asia summer monsoon intensity and （ii） the transition period with increased E1 Nifio/Southern Oscillation activities in the Equatorial Pa- cific. Our SST record provides oceanic evidence for a more global nature of the mid-late Holocene climate change, which was most likely caused by a southward migration of the Intertropical Converge Zone in response to the decreasing summer solar insolation in the Northern Hemisphere. However, the large SST drop around Core B3 indicates that the mid-late Holocene cooling was regionally amplified by the initiation/strengthening of eddy circulation/cold front which caused upwelling and resulted in additional SST de- crease. Upwelling during the mid-late Holocene also enhanced with surface productivity in the East China Sea as reflected by higher alkenone content around Core B3.

关键词： sea surface temperature alkenone East China Sea 4 ka ITCZ

Kinetic Study on the Exothermic First-stage Decomposition Reaction of 2,4,8,10-Tetranitro-2,4,8,10-tetraaza-spiro[5,5]undecane-3,9-dione

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Chinese Journal of chemistry 2004年第10期22卷 1075-1077页

作者：胡荣祖赵凤起王伯周高胜利朱春华宁斌科陈沛罗阳宋纪蓉史启祯 Xi'an Modern chemistry Research institute Department of chemistry Northwest University Xi'an Shaanxi 710069 China

Under linear temperature increase condition the thermal behavior and kinetic parameters of the exothermic first-stage decomposition reaction of the title compound were studied by means of DSC and TG-DTG. The empiri-cal kinetic model function in differential form, apparent activation energy and pre-exponential constant of this reac-tion are 0.122(1-)0.528, 216.4 kJ·mol-1 and 1020.51 s-1, respectively. The critical temperature of thermal explo-sion of the compound is 222.25 ℃. The values of SD, HD, and GD and of this reaction are 108.3 J·ol-1 K-1, 205.1 kJ·ol-1 and 151.4 kJ·ol-1, respectively.

关键词： decomposition 2,4,8,10-tetranitro-2,4,8,10-tetraazaspiroundecane-3,9-dione DSC kinetics TG

Structure and Magnetic Properties of a Bipyridine-bridged One-dimensional Ni(Ⅱ) Coordination Polymer

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Chinese Journal of Structural chemistry 2014年第5期33卷 735-740页

作者：张富青周晶晶黄齐茂周红潘志权 School of chemistry and Environmental Engineering Wuhan Institute of Technology

A polymer, [NiL（bipy）·2H2O]n（1, bipy = 4,4ˊ-bipyridine）, has been acquired by the reaction of Ni（OAc）2·4H2O with N,Nˊ-bis（2-hydroxyl-5-fluorobenzyl）-2-hydrxylpropane dii- mine in the presence of 4,4ˊ-bipyridine. X-ray crystallographic analysis shows that it is comprised of a mononuclear Ni（Ⅱ） complex [NiL] linked by 4,4ˊ-bipyridine. Its crystal crystallizes in the orthorhombic system, space group C2/c with a = 22.595（3）, b = 18.395（2）, c = 15.434（2） , V = 6155（1）3, Dc = 1.259 g/cm-3, Z = 8, Mr = 583.23, F（000） = 2416.0, μ（MoKa） = 0.681 mm-1, S = 1.049, R = 0.0512 and wR = 0.1108 for 6032 observed reflections（I 〉 2σ（I））. There are water hexamers in the complex. A weak overall ferromagnetic behavior has been evaluated by Curie-Weiss rule and by the formula of alternating ferro-ferromagnetic coupling in one-dimensional Ni（Ⅱ） chain, which gives g = 2.005（1） and J1 = 0.31（3） cm-1.

关键词： bipyridine-bridged coordination polymer Ni(Ⅱ) complex magnetic properties water hexamer