2D and 3D Polymeric Wells-Dawson polyoxometelates: synthesis, crystal structures, and cyclic voltammetry of [(M(H(2)O)(4))(x)][H(6-2x)P(2)W(18-n)Mo(n)O(62)] (M = Cu(II), Co(II), Ni(II)).

The synthesis, X-ray crystal structures, cyclic voltammetry, and IR and (31)P NMR characterizations of five new Wells-Dawson-type polyoxometalates are reported, the formulas of which being [(Cu(H(2)O)(4))(2.5)][HP(2)W(18)O(62)].11.

Cooperativity of copper and molybdenum centers in polyoxometalate-based electrocatalysts: cyclic voltammetry, EQCM, and AFM characterization.

Electrochemical behaviors of selected Dawson-type polytungstates including 2-K10[P2W15Mo2O61box] where the symbol [box] designates a vacant site, alpha2-K7[Fe(OH2)P2W15Mo2O61], alpha2-K8[Cu(OH2)P2W15Mo2O61], alpha1- and alpha2-K8[Cu(OH2)P2W17O61], alpha2-K8[Cu(OH2)P2W13Mo4O61], and alpha2-K8[Cu(OH2)P2W12Mo5O61] were investigated by cyclic voltammetry (CV) coupled with the electrochemical quartz microbalance (EQCM), and the results were completed by atomic force microscopy (AFM) observations of the electrodeposited films. The electrocatalytic abilities of these polyoxometalates (POMs) in the reduction of dioxygen, hydrogen peroxide, and NOx were also assessed by CV and EQCM. It turns out that the remarkable electrocatalysis obtained at the reduction potential of Mo centers within alpha2-K8[Cu(OH2)P2W15Mo2O61], but in a domain where Cu2+ is not deposited, benefits from the assistance of the copper center because such catalysis could not be observed in the absence of Cu2+.