The Study Of The Polyoxometalate-based Inorganic-organic Hybrids And Coordination Compounds Assembled With Pyridyl Calix[4]Arenes

Self-assembly of 4-pyridyl-functionalized calix[4]arene ligand?L?and Ag?I?/Cd?II?/Cu?II?/Co?II?cations obtained four polyoxometalate-based inorganic-organic hybrids [Ag₃?L?₂][PMo₁₂O₄₀]·CH₃CN·4H₂O?1?,[Ag₃?L?₂][PMo₁₂O₄₀]·2DMA·0.5EtOH?2?,[CoL][SiW₁₂O₄₀]_0.5·2H₂O?3?,[CuLCl₂][SiW₁₂O₄₀]_0.5·2H₃O?4?and two complexes [Cd₃?L?₂Cl₆]·4CH₃CN·4H₂O?5?and [Ag₃L]·3NO₃^-·2H₂O?6??DMA = N,N-dimethylacetamide?.1 and 2 are one-dimensional chains which are linked by hydrogen bonds between the C atom of L ligands and the O atom of [PMo₁₂O₄₀]^3-anions to generate supramolecular layers.3 is a two-dimensional structure and 4 is a single molecule structure.5 displays a layer containing trinuclear Cd?II?clusters.6 is a one-dimensional chains.1 has good stability in strong acid or base solutions and in these organic solvents?acetonitrile,DMA,ethanol,methanol and acetone solutions?.5 showed good stability only in acetonitrile solvent.Therefore,organic catalytic reactions of 1 and 5 were tested.Complex 1 has good heterogeneous catalytic activity for oxidation and desulfurization reaction,and the conversion rate of thiophene substrates is much lower than that of thioether substrates.Catalytic oxidation of oxidation desulfurization is mainly affected by steric hindrance,but less by electron acceptor or donor groups.Hybrid 1 exhibits obvious electrocatalytic activity for oxidize ascorbic acid and reduce NaBrO₃.Complex 5 shows heterogeneous catalytic ability for Knoevenagel condensation reaction.