Syntheses And Electrochemical Properties Of Keggin-type Polyoxometalate Supramolecular Materials

In this paper，we have synthesised five novel organic-inorganic compoundsbased on Keggin-type polyoxometalates （POMs forshort）:[Mn（H₂O）₂（bimb）₂][SiW₁₂O₄₀]₂bimb₂（1）,[Zn（H₂O）₂（bimb）₂]2[SiW₁₂O₄₀]（2）,[Ni（H₂O）₂（bimb）₂]2[SiW₁₂O₄₀]（3）,[Cd（H₂O）₂（bimb）₂]2[PW₁₂O₄₀]（4）,[Ag（phen）₂]₃[Ag（phen）₃][SiW₁₂O₄₀]（5）.Bimb=1,3-bis（1-imidazoly）benzene，phen=1,10-phenanthroline. The fivecompounds were characterized by IR spectra, single-crystal X-ray diffraction,elemental analysis and electrochemical study.A new orgnic-inorganic compounds1based on [SiW₁₂O₄₀]4-polyanion,organic molecule V-shaped bimb（bimb=1,3-bis（1-imidazoly）benzene） and l Mnatom, has been synthesized through modulating the reaction temperature, rationof reactants, reaction time, pH value. Compounds1belong to Triclinic system.The compounds2-4belong to isomorphic compounds. Bimb has chosen asthe ligand, and chose Zn, Ni, Cd as the metal cations respectively, two kinds ofKeggin-type POMs the building cell. Their structures have been characterized.All of the crystals belong to the triclinic space group, they are one-dimensionalchain structures through the gap between the polyanionic and metal-organicligand ring-like units.Phen （phen=1,10-phenanthroline） as a ligand used widely has been chosento built compound5with Ag and Keggin-type [SiW₁₂O₄₀]4+. to formone-dimensional waving chain structure. One outstanding characteristic of thestructure of compound5is the {[Ag（phen）₂]₃}³⁺unit which is very peculiarly,and the Ag-Ag bond that the structure containing rarely be reported in literatures.In addition, we also studied the electric catalytic properties of compound 1-3, the results show that they have good catalytic activities.