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Syntheses,crystal structures and properties of three novel coordination polymers with tripodal imidazole-containing ligands and benzenetetracarboxylate

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Science china chemistry 2010年第10期53卷 2164-2169页

作者： SU Zhi, FAN Jian & SUN WeiYin State Key Laboratory of Coordination chemistry Nanjing National Laboratory of Microstructures Coordination chemistry Institute, school of chemistry and chemical engineering, Nanjing University, Nanjing 210093, china State Key Laboratory of Coordination chemistry Nanjing National Laboratory of Microstructures Coordination chemistry Institute School of Chemistry and Chemical Engineering Nanjing University Nanjing China

Three novel coordination polymers, [Ni2(tib)2(btec)]·2H2O (1), [Co2(tib)2(btec)]·2H2O (2) and [Zn4(tib)2(btec)Cl4]·2H2O (3), have been synthesized by using mixed ligands of 1,3,5-tris(1-imidazolyl)benzene (tib) and 1,2,4,5-benzenetetracarboxylic acid (H4btec) under hydrothermal conditions. Complexes 1 and 2 have the same structure and are rare three-dimensional (3D) self-penetrating (3,4,5)-connected nets, while complex 3 is an unprecedented (3,4)-connected 3D net. The different structures of 1 (2) and 3 are ascribed to the distinct coordination geometry of the metal centers. The thermal stability and photoluminescence property of the complexes were investigated.

关键词： coordination polymer self-penetration crystal structure thermal stability photoluminescence property

Ag-ZSM-5 Catalyst for the Catalytic Decomposition of NO

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Chinese chemical Letters 1999年第1期10卷 83-86页

作者： Jia Wei TENG Tian Xi CAI Xin He BAO(school of chemical engineering, dalian University of Technology, dalian 116012)(State key Laboratory of Catalysis, dalian Institute of chemical Physics. dalian 116023) school of chemical engineering Dalian University of Technology Dalian 116012 China State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Dalian 116023 China

The catalytic decomposition of NO over Ag-ZSM-5 catalyst prepared by ion-exchange was investigated. The exchanged silver in the zeolite was reduced and it collected in the course of the reaction to form silver particles of about 20 nm. The catalytic reaction induced a pronounced restructuring of the Ag particles through preferential formation of the (111) facets. These facets were shown to hind a tightly bound oxygen species (O-gamma). The O-gamma species occupies the active sites for NO adsorption resulting in catalyst deactivation. It could be removed by appropriate reducing agents, such as CO, to recover the active sites at elevated temperatures.

关键词： Ag-ZSM-5 catalyst NO decomposition

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 State Key Laboratory of chemical Resource engineering Beijing University of Chemical Technology

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

Synthesis and purification of trialkyl compounds of gallium and indium

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Rare Metals 2002年第1期21卷 1-6页

作者： SHU Wangen, ZHOU Zhongcheng and LI Xiong chemistry and chemical engineering College, Central South University, Changsha 410083, china chemistry and chemistry engineering College Central South University Changsha 410083 chemistry and chemical engineering College Central South University Changsha 410083

The The research progress in trialkyl compounds of gallium andindium was discussed from two aspect, one was the chemical synthesisof the compounds and the other was the purification of them. Thereare three synthesis routes be- ing reported in the first aspect, *** route staring form pure metal, the route starting from the puremetal trihalides, and the electrochemical route. In the secondaspect, the purifying methods of decomposition-distillation and zonerefining were reviewed.

关键词： trialkyl compounds gallium nd indium synthesis purification

Hydroisomerization of n-heptane over bimetal-bearing H_3PW_(12)O_(40) catalysts supported on dealuminated USY zeolite

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Science china chemistry 2008年第2期51卷 120-127页

作者： WEI RuiPing1,2, GU YanBo1 & WANG Jun1 1 State Key Laboratory of Materials-Oriented chemical engineering, College of chemistry and chemical engineering, Nanjing Uni- versity of Technology, Nanjing 210009, china 2 College of chemistry and chemical engineering, Southeast University, Nanjing 211189, china State Key Laboratory of Materials-Oriented chemical engineering College of Chemistry and Chemical EngineeringNanjing University of TechnologyNanjing 210009China College of chemistry and chemical engineering Southeast UniversityNanjing 211189China

The bimetal-bearing (CePt or LaPt) 12-tungstophosphoric acid (H3PW12O40 (PW)) catalysts supported on dealuminated USY zeolite (DUSY) were prepared by impregnation and characterized by XRD, BET, IR, and H2-chemisorption. Their catalytic activities were tested in the hydroisomerization of n-heptane with a continuous atmospheric fixed-bed reactor. After the steam treatment combined with the acid leaching, as well as the supporting with PW and the bimetals, the DUSY support retains the Y zeolite porosity and the PW well keeps its Keggin structure in catalysts. The doping of Ce into the catalysts enhances the dispersion of Pt on the catalyst surface. The Pt-bearing PW catalysts doped with Ce or La, especially Ce, exhibit much higher catalytic activity and selectivity than the catalysts without dopants at lowered reaction temperatures. At the optimal reaction conditions, i.e., the reaction temperature of 250℃ and WHSV of 1.4 h1, the catalyst with a Pt loading of 0.4%, PW loading of 10% and a molar ratio of Ce to Pt of 15:1 shows a conversion of n-heptane of 70.3% with a high selectivity for isomerization products of 94.1%.

关键词： hydroisomerization of n-heptane bimetal catalyst heteropoly acid USY platinum

Mathematic Expression of Kinetic Compensation Effect and Relationship between the Exothermic Decomposition Temperature and Critical Temperature of Thermal Explosion of Eighty-six Energetic Materials

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含能材料 2001年第1期9卷 8-9页

作者： HU Rong zu 1, YANG De suo 2, ZHANG Jiao qiang 3 (1. Department of chemistry,Northwest University, Xi′an 710065, china 2. Department of chemistry and chemical engineering, Baoji College of Arts and Science, Baoji 721007, china 3. Department of 西北大学陕西西安 710065 宝鸡文理学院陕西 721007 西北工业大学陕西西安 710072

Two relationships are established using the least squares method,between the kinetic parameters (the apparent activation energy and pre exponential constant),and the exothermic decomposition temperature and ther... 详细信息

关键词： critical temperature of thermal explosion decomposition temperature DSC energetic materials.

Synthesis and characterization of six-arm star-shaped liquid crystalline cyclotriphosphazenes

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Chinese chemical Letters 2010年第6期21卷 682-685页

作者： Rui Bao,Min Pan,Jin Jun Qiu,Cheng Mei Liu~* school of chemistry and chemical engineering,Huazhong University of Science and Technology,Wuhan 430074,china school of chemistry and chemical engineering Huazhong University of Science and Technology Wuhan 430074 China

The synthesis and mesomorphic properties of a new class of liquid crystalline cyclotriphosphazenes with rigid cyanostilbene groups and flexible alkoxy groups are *** thermal behaviors of cyclotriphosphazene derivatives 5a-5d are studied by the means of differential scanning calorimetry,polarizing optical *** phases were observed in compounds 5a-5d both on heating and *** clear temperatures of compounds 5a-5d slightly increased with increasing length of terminal alkyl *** 5a-5d showed different mesogenic region from minimum 5℃to maximum 142℃.

关键词： Cyclotriphosphazene Cyanostilbene Liquid crystal Star-shaped molecule Synthesis

Regioselective aminohalogenation of β-nitrostyrenes using NCS and NBS as nitrogen/halogen sources

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Science china chemistry 2010年第1期53卷 140-146页

作者： ZHI SanJun1,2,SUN Hao2,LIN Chen2,ZHANG GuangQian2,LI GuiGen4 & PAN Yi2,3 1 Department of chemistry,Huaiyin Normal University,Huai’an 221003,china 2 school of chemistry and chemical engineering,Nanjing University,Nanjing 210093,china 3 State Key Lab of Coordination chemistry,Nanjing University,Nanjing 210093,china 4 Department of chemistry and Biochemistry,Texas Tech University,Lubbock,Texas 79409-1061,USA Department of chemistry Huaiyin Normal University Huai’an China school of chemistry and chemical engineering Nanjing University Nanjing China Department of chemistry and Biochemistry Texas Tech University Lubbock USA State Key Lab of Coordination chemistry Nanjing University Nanjing China

Aminohalogenation reaction of β-nitrostyrenes with N-halosuccinimides(N-chloro and N-bromosuccinimides) has been successfully conducted by using nickel acetate as a catalyst in the presence of potassium carbonate and succinimide as *** reaction was easily performed at room temperature under nitrogen gas protection to give dihalorinaed haloamino products in good to excellent yields(60%-98%).The structure has been confirmed by X-ray crystal structure analysis.

关键词： aminohalogenation vicinal haloamines β-nitrostyrenes NBS NCS

Binaphthyl-bridged bis-imidazolinium salts as N-heterocyclic carbene ligand precursors in the palladium-catalyzed Heck reaction

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Science china chemistry 2011年第6期54卷 951-956页

作者： WU Hui, JIN Can, HUANG GuoLi, WANG LianJun, JIANG JuLi & WANG LeYong Key Laboratory of Mesoscopic chemistry of Ministry of Education school of chemistry and chemical engineering, Nanjing University, Nanjing 210093, china Key Laboratory of Mesoscopic chemistry of Ministry of Education school of chemistry and chemical engineering Nanjing University Nanjing China

Two new bis-imidazolinium salts (4a, 4b) have been synthesized as precursors of N-heterocyclic carbenes (NHCs) from the commercially available (R)-2,2′-dihydroxy-1,1′-binaphthalene. The two bis-imidazolinium salts were used as efficient precursor of NHC ancillary ligands in the palladium-catalyzed Heck reaction. Good to excellent yields and high stereoselectivities were obtained with ethyl acrylate, acrylonitrile, and acrylamide as starting materials. The structure of bis-imidazolinium salt 4b was further characterized by single crystal X-ray diffraction analysis.

关键词： N-heterocyclic carbenes Heck reaction palladium imidazolinium salts