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Recent advances in polyoxometalates acid-catalyzed organic reactions

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Chinese Chemical Letters 2023年第5期34卷 143-154页

作者： Yu-Feng Liu chang-wen hu Guo-Ping Yang Jiangxi Province Key Laboratory of Synthetic Chemistry Jiangxi Key Laboratory for Mass Spectrometry and InstrumentationEast China University of TechnologyNanchang 330013China Key Laboratory of Cluster Science of Ministry of Education Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion MaterialsSchool of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 100081China

Polyoxometalates(POMs)have conducive properties such as controlled Bronsted and Lewis acidity,high thermal stability,nontoxic nature,tunable solubility,and less *** have been extensively applied in catalytic organic reactions and have an exciting prospect for industrial *** review summarized recent progress in the application of POMs as acid catalysts for various organic reactions including C-C bond formation,C-N bond formation,C-O bond formation,heterocyclic synthesis reactions,cyanosilylation and hydrolysis *** POMs catalysts including heteropoly acids(HPAs)and cationic functionalized HPAs with Bronsted acidity,HPAs supported on non-precious metal support with Bronsted acidity(or both Bronsted and Lewis acidity),transition metal substituted POMs with Lewis acidity were applied in above *** review attempts to provide up-to-date information about POMs acid-catalyzed organic reactions and propose future prospects.

关键词： Polyoxometalates Acid catalysis C-C bond formation C-N bond formation C-O bond formation Heterocyclic synthesis Cyanosilylation and hydrolysis reactions

Simple Preparation of the Photocatalyst of Sn^(2+)-doped Titania

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Chinese Chemical Letters 2006年第8期17卷 1089-1092页

作者： Dao Rong LI Ling Na SUN chang wen hu Department of Chemistry Beijing Institute of Technology Beijing 100081 Department of Chemistry Henan University of Technology Zhengzhou 450052

Preparation method of photocatalyst, using TiCl4 and SnCl2 as raw material and photocatalytic activity of nano-scaled core-shell Sn^2＋ -doped titania photocatalyst was studied in this paper. The as-prepared samples were studied by UV-Vis, XRD, XPS, TEM. The particles of Sn^2＋-doped TiO2 photocatalyst, calcined from 150 to 600 ℃ for 5 h, possesses narrow particle size distribution and the sample was composed of anatase phase. Its photocatalytic efficiency was investigated by UV irradiation.

关键词： Compound semiconductors preparation photocatalysis.

Photocatalytic Dye Methyl Orange Decomposition on Ternary Sulfide (CdIn2S4) under Visible-light

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Chinese Chemical Letters 2005年第9期16卷 1259-1262页

作者： Xiao Dan YU Xue Song QU Yi Hang GUO chang wen hu Faculty of Chemistry Northeast Normal University Changchun 130024 Department of Chemistry Beijing Institute of Technology Beijing 100081

A novel and efficient photocatalyst, CdIn2S4, was simply prepared by a programmed temperature hydrothermal method. The product had a nanometer size （10-15 nm） and strong absorption in the range of 200 to 580 nm, and... 详细信息

关键词： Ternary sulfides hydrothermal treatment visible-light photocatalysis methyl orange

Orientations of Rare-earth-containing Heteropolyoxometalates with Different Sizes in the Interlayer of Synthetic Multibilayer Films

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Chinese Chemical Letters 2002年第9期13卷 887-890页

作者： Yong hui WANG Xin Long WANG chang wen hu En Bo WANG Institute of Polyoxometalate Chemistry Faculty of ChemistryNortheast Normal UniversityChangchun 130024

Three rare-earth-containing heteropolyoxometalates with different sizes, Na9[Eu(W5 O18)2], K13[Eu(SiW11O39)2], and K17[Eu(P2W17O61)2], have been incorporated by self-assembly into the interlayer of synthetic multibila... 详细信息

关键词： Rare-earth-containing heteropolyoxometalate synthetic multibilayer film DODA orientation.

Design and synthesis of hybrid solids based on the tetravanadate core toward improved catalytic properties

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Chinese Chemical Letters 2016年第5期27卷 649-654页

作者： Yan-Hong Niu Song Yang Ji-Kun Li Yan-Qing Xu chang-wen hu Key Laboratory of Cluster Science Ministry of Education of China Beijing Key Laboratory of PhotoelectronicElectrophotonic School of Chemistry Beijing Institute of Technology

Five inorganic-organic hybrid vanadates based on tetravanadate cores, transition metals and N-donor ligands have been designed and synthesized under hydrothermal conditions, namely, [Zn（elM）312V4O12 （1）, [Zn（plM）3]2V4O12.H2O （2）, [Zn（iplM）3]2V4O12 （3）, [Co（eIM）3]2V4O12.H2o （4）, [Cu（eIM）2（H20）]2V4O12 （5）（eIM = 1-ethylimidazole, plM = 1-propylimidazole, ipIM = isopropylimidazole）. All compounds were fully characterized by single-crystal XRD, powder XRD, elemental analysis, TGA, and FT-IR spectroscopy. The hybrid zinc vanadates （1-3） and cobalt vanadate （4） exhibit interesting 2D folded structures and the hybrid copper vanadate （5） presents a 1D chain configuration. All compounds can catalyze olefin epoxidation reactions when using TBHP （TBHP = tert-butyl hydroperoxide） as an oxidant in acetonitrile. The introduction of transition metal ions into tetravanadate cores not only improved the catalytic activity but also fulfilled the heterogeneous catalytic behavior. 1-5 all exhibit extraordinary efficiency in converting olefins to the corresponding epoxides with high conversion and selectivity （particularly, cony. up to 97.1%, sele. up to 100% for 1 ）. Leaching test was also carried out to prove the heterogeneous behavior.

关键词： Hybrid Tetrvanadate core Heterogeneous catalysts Olefin epoxidation

Supramolecular assembly of Keggin polyoxomolybdate and 2,2'-bipyridine generated in situ from a decarboxylation coupling reaction

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Chinese Chemical Letters 2013年第7期24卷 578-580页

作者： Chun-Hong Li Qiang Wang Ying-Nan Chi Xin-Fang Wang chang-wen hu National Laboratory for Superconductivity Institute of Physics and Beijing National Laboratory for Condensed Matter PhysicsChinese Academy of Sciences Laboratory for Micro-sized Functional Materials College of Elementary EducationCapital Normal University Key Laboratory of Cluster Science Ministry of Education of ChinaSchool of ChemistryBeijing Institute of Technology

An assembly of Keggin polyoxomolybdate and organic substrate （Hbipy）3[PM01204o] （1, bipy = 2,2＇- bipyridine） was synthesized and characterized by elemental analysis, infrared spectrum, and single- crystal X-ray analysis. The ligand bipy of compound 1 was generated by a decarboxylation coupling reaction of H2pdc （H2pdc = pyridine-2,6-dicarboxylic acid） in situ under hydrothermal reaction conditions and the control experiments illustrate that La（NO3）3 or Ce（NO3）3, which does not appear in the final structure, is necessary for the decarboxylation coupling reaction. Moreover, compound 1 displays strong photoluminescence property in the solid state at room temperature.

关键词： Polyoxometalates Decarboxylation coupling In situ Photoluminescence

Tetrabutylammonium salts of tritransition-metal-substituted A-α-tungstogermanate:Halogen-free and single-component catalysts for the coupling reaction of carbon dioxide and epichlorohydrin

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Chinese Chemical Letters 2011年第7期22卷 871-874页

作者： Fa Wang Chen Tao Dong Xiao Fang Li Tie Gang Xu chang wen hu Key Laboratory of Cluster Science Ministry of Education of China Belting Institute of Technology Beijing 100081 China School of Material Engineering Jinling Institute of Technology Nanjing 211169 China

The green synthesis of chloropropylene carbonate via the coupling reaction of carbon dioxide and epichlorohydrin had been achieved using halogen-free and single-component catalysts tetrabutylammonium salts of tritransition-metal-substituted A-α- tungstogermanate [（n-C4H9）4N]3H7GeW9M3（H2O）30O7 （M = Cu^Ⅱ, Ni^Ⅱ, Co^Ⅱ and Mn^Ⅱ） without any solvent. The catalytic activity was significantly depended on the transition metal introduced in polyoxometalates. [（n-C4H9）4N]3H7GeW9Mn3（H2O）3O37 exhibited the highest catalytic activity with 94.9% conversion for epichlorohydrin and 98% selectivity for chloropropylene carbonate in 3 h. Plausible mechanism was proposed based on the results.

关键词： Cyclic carbonate Catalysis Carbon dioxide Polyoxometalates

Kinetics of Photocatalytic Degradation of Formic Acid over Silica Composite Films Based on Polyoxometalates

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Chinese Chemical Letters 2002年第6期13卷 575-578页

作者： Dan Feng LI Yi Hang GUO chang wen hu Li MAO En Bo WANG Institute of Polyoxometalate Chemistry Northeast Normal UniversityChangchun 130024

The composite films, XW11O39n-/SiO2, (X refers to Si, Ge or P, respectively) were prepared by tetraethoxysilane (TEOS) hydrolysis sol-gel method via spin-coating technique. Formation of the composite films is due to strong chemical reaction of organic silanol group with the surface oxygen atoms of XW11O39n-, resulted in the saturation of the surface of the lacunary polyoxometalates (POMs). Therefore, the coordination structural model of the films was proposed. As for the films, retention of the primary Keggin structure was confirmed by UV-vis, FT-IR spectra and MAS NMR. The surface morphology of the films was characterized by SEM, indicating that the film surface is relatively uniform, and the layer thickness is in the range of 250~350 nm. Aqueous formic acid (FA) (0-20 mmol/L) was degraded into CO2 and H2O by irradiating the films in the near-UV area. The results show that all the films have photocatalytic activities and the degradation reaction follows Langmuir-Hinshelwood first order kinetics.

关键词： Polyoxometalates sol-gel spin coating composition film photocatalysis kinetics formic acid.

Synthesis and characterization of a novel high thermally stable energy compound:1-(1-Adamantylamino)-2,4,6-trinitrobenzene

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Chinese Chemical Letters 2008年第10期19卷 1147-1150页

作者： Sheng Jun Luo Wan Long Pan Ying Nan Chi Yan Qing Xu Kun Lin huang chang wen hu The Institute for Chemical Physics and Department of Chemistry Beijing Institute of Technology Beijing 100081 China State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing 100081 China

1-（1-Adamantylamino）-2,4,6-trinitrobenzene （1） as a potential energy material has been synthesized in excellent yield and characterized by FT-IR, 1H NMR and single crystallographic methods, and is thermally stable... 详细信息

关键词： Admantanamine Tfinitrobenzene Pyrolysis Thermally stable