Synthesis,structure and electrochemical behavior of an organic-inorganic hybrid compound based on Dawson-type polyoxometalates

An organic-inorganic hybrid compound constructed from Wells-Dawson polyanion clusters and metal-organic complex subunits, Cu(phen)₃]Cu(phen)₂Cu(phen)₂(P₂W₁₈O₆₂)]·2H₂O (1) has been prepared hydrothermally and characterized by elemental analysis, IR, UV, cyclic voltammetry (CV) and single-crystal X-ray diffraction. Crystal structural analysis indicates that two terminal oxygen atoms of the Wells-Dawson polyanion located in the “belt” site coordinate with Cu²⁺. Three Cu ions have different coordination environments: Cu1 and Cu2 are five-coordinate, while Cu3 is six-coordinate. The bisupporting polyoxoanions Cu(phen)₂Cu(phen)₂(P₂W₁₈O₆₂)]^2? are polymerized into a 1D chain by hydrogen bonding interactions, then the chains are stacked into a two-dimensional structure via offset, face-to-face, π ··· π stacking interactions. CV reveals that 1 exhibits three chemically-reversible processes.