Preparation, characterization and electrochemical investigation of a new inorganic–organic hybrid material based on Keggin-type polyoxometalate and organic imidazole cation

A new soluble inorganic–organic hybrid based on polyoxotungstate, [Himi]4[SiW12O40].H2O 1 (imi = Imidazole), has been successfully synthesized and characterized by using elemental analysis, infrared spectrum, 1H NMR technique and single-crystal X-ray diffraction. X-ray crystallography reveals that 1 displays an organic–inorganic hybrid frameworks constructed by [SiW12O40]4−α-Keggin-type polyoxoanion and four {(Himi)}+ monocationic hydrogen-bonded fragments. Redox activities for the tungsten centers have been observed using cyclic voltammetry. It was found that 1 presents good electrocatalytic activities for the reduction of −NO2NO2− rather than H4SiW12O40 heteropolyacid.

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