Syntheses,Characterization And Properties Of Novel Inorganic-organic Hybrid Based On Polyoxomolybdates And Nitrogen Heterocycle

The aim of this thesis is the synthesis of a new series of hybrid compounds based on the inorganic building block of molybdenum clusters via aqueous solution synthesis.We explored the synthesis conditions of such compounds,reaction law,and the relationship between structure and properties.Eleven new polyoxomolybdates cluster compounds have been isolated by using one-pot self-assembly method.These eleven compounds were characterized by elemental analyses,IR,UV-Vis,TG and XPS.The thermal stabilities,electrocatalytic activities and semiconducting properties of these compounds have been studied.1.Three new α-Keggin-type isopolyoxomolybdate 1-3,was successfully synthesized under conventional conditions.The crystal structure of compound 1 contains Keggin isopolyanions [Mo_0.5Mo₁₂O₄₀]^5-and imidazole cations.（C₃H5N₂）₄H[Mo_0.5Mo₁₂O₄₀]·H₂O（1）（C₄H₇N₂）₅[Mo_0.5Mo₁₂O₄₀]·10H₂O（2）（C₃H5N₂）₄H[Mo_0.5Mo₁₂O₄₀]·1.5H₂O（3）The three compounds 1-3 are isomorphous.In compound 1-3,a disordered Mo O₄ tetrahedral is surrounded by 12 Mo O6 octahedra,where the valences of Mo atoms are all in their highest valence of +6.To the best of our knowledge,it is the first observation of oxidation state Keggin-type complex in isopolymolybdates system.The p H value of the system is a vital factor in the syntheses of the three compounds.The electrocatalytic experiments show that compound 1-3 possess good electrocatalytic activity for nitrite and peroxydisulfate reduction.2.Bias the starting materials,combining a conventional self-assembly reaction in aqueous solution,three new compounds 4-6 have been synthesized by lanthanide ions and [Mo_0.5Mo₁₂O₄₀]^5-units.:(C₅₆H₃₉N₁₆O₃₅Bi₄)[Mo_0.5Mo₁₂O₄₀]·25H₂O（4）[（C₇H₅N₂O₄）₂SbH₂] [Mo_0.5Mo₁₂O₄₀]·17H₂O（5）[（C₇H₅N₂O₄）₃LaH₂] [Mo_0.5Mo₁₂O₄₀]·15H₂O（6）Complexs 4-6 contain a [Mo_0.5Mo₁₂O₄₀]^5-moiety with Bi3+ or Ln 3+ coordinated by 2,6-PDC.The semi-conducting property of compound 4 was investigated by photophysical measurements,showing the characteristics of n-type semiconductor.In the antibacterial experiments of staphylococcus aureus,complexs 4 showed positive results.3.An inorganic-organic hybrid compound 7 based on both the new molybdovanadate species [VMo7O26]^5-and the isoniazid dimer was synthesized.In compound 7,twelve surface oxygen atoms of [VMo7O26]^5-cluster are exploited to make coordination linkage with other components;creating the highest coordination connection in molybdovanadates subfamily.Interestingly,the in situ isoniazid dimerization reaction could react during the synthesis process.H4K2Na2（H₂O）₄（C12H12N4O2）（VMo7O26）2·10H₂O（7）Structural refinement of the population parameters indicates that a vanadium atom is of disordered occupy over three different positions of metal center.The structure of anion [VMo7O26]^5-is the same as that of anion β-[Mo8O26]4-.4.Three new heteropoly blue compounds are synthesised by heteropolymolybdates and isoniazid.The heteropolymolybdates are reduced by isoniazid.（C6H5NO2）₃（H₂PMo12O₄0）·9H₂O（8）（C6H₇N3O）₄（H₂SiMo12O₄0）·8H₂O（9）（C6H₇N3O）₃（H₃GeMo12O₄0）·10H₂O（10）The electrocatalytic experiments show that compound 8-10 possess good electrocatalytic activity for nitrite and bromate reduction.In the antibacterial experiments of staphylococcus aureus,compound 9 showed positive results.