[Cu(4,4′-bipy)]2[H4P2W18O62] · 2H2O: The first three-dimensional framework based on saturated Wells–Dawson POMs modified by multi-track Cu–N coordination polymeric chains

A new double bitrack Cu–N coordination polymeric chain-modified Wells–Dawson POMs, [Cu(4,4′-bipy)]2[H4P2W18O62] · 2H2O (1), has been synthesized and characterized by IR, TG and single crystal X-ray diffraction. It represents the first example that saturated Wells–Dawson POMs are covalently linked by transition metal coordination polymers into a 3D structure. Additionally, its electrochemical property has been studied, undergoing three two-electron reversible redox processes.