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Zhengzhou, China

Wei M.-L.,Henan Normal University | Sun J.-J.,Henan Normal University | Duan X.-Y.,Henan Academy of science
European Journal of Inorganic Chemistry | Year: 2014

A metal-Schiff-base-POM-MOF, {[Cu3(L)2(H 2O)4] [Cu(dmf)4(SiW12O 40)]·9H2O}n {L = N,N-bis[(2-hydroxy-3- methoxyphenyl)methylidene]hydrazine hydrate}, has been synthesized in situ from [SiW12O40]4-, Cu2+ and L in an H2O/dmf/CH3OH/CH3CN mixture at room temperature, and the product was characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction analysis. X-ray diffraction analysis revealed that the title complex presents a 3D network constructed from CuII-Schiff-base cations, 1D POM-MOF chains and solvent water molecules. Its water vapour adsorption isotherm at room temperature and pressure shows that the water vapour adsorbed by the complex is 51.67 cm3 g-1 at the maximum allowable humidity, which corresponds to 7.1 water molecules per unit formula. In addition, it exhibits good proton conductivity (>10-4 S cm-1) at 100 °C in the relative humidity range 35-98 %. The corresponding activation energy (Ea) of conductivity was estimated to be 0.32 eV. A 3D metal-Schiff-base-POM-MOF has been constructed by combining in situ two traditional building blocks, a metal-Schiff-base and POM-MOF, and its structure was determined by single-crystal X-ray diffraction. Due to the bonding of H2O to otherwise open coordination sites on Cu2+ ions, it shows good proton conductivities of 10-5-10-4 S cm-1 in the temperature range of 25-100 °C under 98 % RH. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Tang X.,Xiamen University | Zeng X.,Xiamen University | Li Z.,Xiamen University | Hu L.,Huaiyin Normal University | And 4 more authors.
Renewable and Sustainable Energy Reviews | Year: 2014

Recently, valorization of lignocellulosic biomass, the most abundantly available biomass raw material on the Earth, to biofuels and chemicals has attracted great attention worldwide for the purpose of reducing our overwhelming reliance on the non-renewable petroleum resources. γ-Valerolactone (GVL) has recently been hailed as a versatile building block which can be derived from renewable lignocellulosic biomass resource for energy, chemical and material sectors. In this review, focus was principally put on the applications of GVL as a renewable carbon source for green solvents and transportation fuels. In addition, advances in the GVL production through selective reduction of commercial or biomass-derived levulinic acid (LA) and its esters using various hydrogen sources, mainly including molecule H2, formic acid (FA) and alcohols, have been carefully summarized. Moreover, assessment of the relative merits of different hydrogen sources for the GVL production has also been performed. © 2014 Elsevier Ltd. Source

Wei M.,Henan Normal University | Wang X.,Henan Normal University | Sun J.,Henan Normal University | Duan X.,Henan Academy of science
Journal of Solid State Chemistry | Year: 2013

We have succeeded in constructing a 3D POM-MOF, {H[Ni(Hbpdc)(H 2O)2]2[PW12O40] ·8H2O}n (H2bpdc=2,2′-bipyridyl-3, 3′-dicarboxylic acid), by the controllable self-assembly of H 2bpdc, Keggin-anions and Ni2+ ions based on the electrostatic and coordination interactions. Interestingly, Hbpdc- as polydentate organic ligands and Keggin-anion as polydentate inorganic ligands are covalently linked transition-metal nickel at the same time. The title complex represents a new example of introducing the metal N-heterocyclic multi-carboxylic acid frameworks into POMs chemistry. Based on Keggin-anions being immobilized as part of the metal N-heterocyclic multi-carboxylic acid framework, the title complex realizes four approaches in the 1D hydrophilic channel used to engender proton conductivity in MOFs. Its water adsorption isotherm at room temperature and pressure shows that the water content in it was 31 cm3 g-1 at the maximum allowable humidity, corresponding to 3.7 water molecules per unit formula. It exhibits good proton conductivities (10-4-10-3 S cm-1) at 100 C in the relative humidity range 35-98%. The corresponding activation energy (E a) of conductivity was estimated to be 1.01 eV. © 2013 Elsevier Inc. Source

Hou D.N.,Henan Academy of science
Structural Chemistry | Year: 2014

The O 4-methylthymine (m4T) is a nucleobase lesion induced by the action of ionizing radiation on thymine residue in DNA. In this study, we present the hydrogen-bonding base pairs involving m4T bound to the four bases in DNA: adenine (A), cytosine (C), guanine (G), and thymine (T). Full geometry optimizations have been performed for the studied complexes by MP2 method. The interaction energies were corrected for the basis-set superposition error, using the full Boys-Bernardi counterpoise correction scheme. Hydrogen-bonding patterns of these base pairs were characterized using NBO analysis and AIM analysis. According to the calculated binding energies and structural parameters, the stability of the base pairs decrease in the following order: m4T:G > m4T:A > m4T:C > m 4T:T. © 2013 Springer Science+Business Media New York. Source

Duan J.,Tianjin Institute of Urban Construction | Liu R.,Zhengzhou University | Chen T.,Henan Academy of science | Zhang B.,Zhengzhou University | Liu J.,Zhengzhou University
Desalination | Year: 2012

The magnetic composite of Fe 3O 4-halloysite nanotube (HNT) was prepared by chemical precipitation method. The prepared adsorbents were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), and multipoint Brunauer-Emmett-Teller (MBET). The results revealed that Fe 3O 4 particles with diameter of 3-5nm dispersed on the nanotube surface and formed a composite with halloysite. The Fe 3O 4-HNTs composite exhibited fine magnetic property (Ms=8.47emu/g) and could be easily separated from aqueous solution by the application of an external magnetic field. Adsorption results showed that Fe 3O 4-HNTs composite could maintain a high adsorption capacity for methyl violet (MV) when the pH, concentration of metal ion and temperature varied. Adsorption kinetics was best described by the pseudo-second-order model. Equilibrium data fitted well with the Langmuir isotherm. The used Fe 3O 4-HNTs could be regenerated by simple calcinations. The recovered adsorbents could be used again for MV removal and magnetic separation. Because of the excellent adsorption capacity at different conditions, reproducibility and separability, Fe 3O 4-HNTs composite is a promising candidate for removing cationic dye from waste water. © 2012 Elsevier B.V. Source

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