| It is reported that nine transition-metal complexes based on Keggin-polyoxotungstates anions have been synthesized under hydrothermal and solvothermal conditions. To the best of our knowledge, seven of them have not been reported until now. Their structures have been characterized by single crystal X-ray diffraction analysis et al. and photocatalytic H2 evolution, fluorescent properties and electrochemical properties have been studied for some of them .1. Seven 3D complexes based on Keggin-polyoxotungstates anions, 2-Hpzc and Cu(II)/Ag(I) have been synthesized hydrothermally: [Cu6(2-pzc)5(H2O)2(SiW12O40)]·H2O 1 [Cu3(pz)3(HSiW12O40)] 2 [Cu6(2-pzc)5(H2O)2(GeW12O40)]·H2O 3 [Cu10(pz)12Cl2(H2O)2(GeW12O40)][GeW12O40] 4 [Cu10(pz)12Cl2(H2O)2(SiW12O40)][SiW12O40] 5 [Ag4(pz)3(H2O)2(GeW12O40)]·2H2O 6 [Ag4(pz)3(H2O)2(SiW12O40)] 7 Comlexes 1 and 3 are isomorphous. There are channels in the 3D cation framework formed by Cu(I/II) and 2-pzc and the [XW12O40]4- anions are filled in the channels. In complex 2, each [SiW12O40]4- anion act as a six-connected ligand link six adjacent 1D chains of [Cu(pz)]nn+ into 3D structure. Complexes 4 and 5 are isomorphous. A-[XW12O40]4- anions act as building blocks link adjacent double layers into 3D structure with nano-size channels and B-[XW12O40]4- anions act as counter-ions are filled in the channels. Complexes 6 and 7 are isomorphous, {Ag2(pz)(H2O)2}2+ fragments are linked with [XW12O40]4- polyoxoanions into a 2D layer. Furthermore, the layers are linked into a 3D architechture via the infinite [Ag(pz)]nn+ chains.2. Two 1D double-chain complexes based on Keggin-polyoxotungstates anions, Cu(II) and different ligands dpa/4,4'-bipy have been synthesized solvothermally: [Cu2(dpa)2(H2O)2(GeW12O40)]·0.5CH3COOH 8 [Cu2(bipy)2(SiW12O40)]·H2bipy 9In complex 8, the [GeW12O40]4- anions are linked through [Cu(2)(dpa)(H2O)2]2+ fragments into a row. Furthermore, two rows of [GeW12O40]4- anions are linked through [Cu(1)(dpa)]2+ cations into a 1D double-breasted chain. In complex 9,the [SiW12O40]4- anions are linked through two [Cu(4,4'-bipy)]n2n+ chains into a 1D double-chain.3. Photocatalytic H2 evolution have been studied for complex 1 and complexes 3-9. They exhibit the photocatalytic activity for H2 evolution. Average H2 evolution rates are 2.29, 2.70, 3.87, 4.35, 7.56, 6.96, 1.17 and 1.24μmol/h, respectively. |
PDF Full Text Request