A new 3D polyoxometalate based on saturated Wells-Dawson polyanions and calcium cations

A new polyoxometalate based on saturated Wells-Dawson polyanions and calcium cations, H-2[Ca-2(P2W18O62)(H2O)(5)] center dot 7.5H(2)O (1), has been synthesized in aqueous solution and characterized by single-crystal X-ray diffraction and IR. Compound 1 is a new example of 3D framework based on Wells-Dawson anions that act as chelate ligands to coordinate with calcium cations. Cyclic voltammetry reveals that the pH of the supporting electrolytic solution has a marked effect on the electrochemical behavior.