A mixed-addenda Nb/W polyoxometalate containing dimeric Dawson subunit: Synthesis, structure, and characterization

By reaction of [Nb6O19]8 − and hexavacant [H2P2W12O48]12 − under acidic condition, a mixed-addenda Nb/W polyoxometalate, K4Na4[H6P2W12Nb4O59(NbO2)2]2 · 48H2O, was obtained. The polyoxoanion contains a dimeric structure which is constructed by joining two {P2W12Nb6} monomers through two Nb-O-Nb bridges. The peroxo groups of the {P2W12Nb6} monomers were partial eliminated during the formation of the dimeric structure. The electrochemical property of the title compound was studied by CV and its electrochemical reduction of nitrite was also evaluated.