The Synthesis And Properties Research Of Metal Organic Coordination Compounds Based On Polyoxovanadates With High Core

This paper prepared a series of new metal organic coordination compounds by the reaction between transition metal or alkaline-earth metals and polyoxometallate or dicarboxylic acid ligands under hydrothermal conditions. At the same time, the reacton conditons, the topology types of the network as well as its intermolecular forces, the ligand geometry and other laws were analyzed and summarized. On the other hand, we also explored the relationship between the structures of the new materials and their properties.With the exploration of the reaction solution pH, temperatures and ingredients, we used situ synthesis method and room temperature aqueous solution synthesis technology successfully preparing five new metal-organic framework complexes; these compounds were characterized by single crystal X-ray diffraction, elemental analysis, IR spectra and powder X-ray diffraction. Furthermore, the electrochemical property, water solubility and catalytic activity of these substances were studied deeply.1. Under hydrothermal conditions, By using copper nitrate, ammonium metavanadate and sodium dihydrogen phosphate as the additives and adding ethylenediamine to adjust the pH, two new polyoxovanadates cluster were obtained:[Cu(en)2]4[Na2V16O42(VO4)]·2H2O (1)[Cu(en)2]5[V18O42(VO4)]·2H2O (en=ethylenediamine)(2)Compound1contains a novel bisodium-substituted [Na2V16O42(VO4)] cluster (Na2V16) with an encapsulated [VO4] core. The Na2V16cluster exhibits a eight-connected model by providing eight terminal O atoms to link eight [Cu(en)2] units, generating a three-dimensional (3D) network. Compound2is formed from classical V18cluster encapsulating [VO4]. And constructed a three-dimensional network which similar with Compound1via [Cu(en)2] linking units, Furthermore, the electrochemical property of1has been studied.2. By using NH4VO3, NaH2PO4and H2O in hydrothermal reaction. A new polyoxovanadates cluster encapsulating [VO4] core:[Na(H2O)4][H4V18O42(VO4)]·16H2O (3)with good water-soluble properties was obtained.(H2O)32-shell structure constructed by two unique water molecules in high symmetry crystal leads to the good water-solubility of compound3.3. Choosing dicarboxylic and transition metal or alkaline-earth metal as the starting materials, two metal organic coordination compounds:[Co(C11H11ClO4)2]·2H2O (4)[Zn(C11H11ClO4)2]·2H2O (L=3-(4-Chlorophenyl) glutaric acid)(5)were obtained and it was found that compound4had good behaviors in selecting oxidation of cyclohexane. Compound4are excellent catalysts not only in conversion but in selectivity for the reaction of cyclohexane oxidation (selectivity:90.32%, conversion:26.58%). And the catalyst yielded the highest conversion of26.58%for cyclohexane, comparing with other coordination polymer type catalysts.