Synthesis and Characterization of Fe- or Cu-Substituted Molybdenum-Enriched Tungstodiphosphates

Abstract

Stereospecific routes were followed to synthesize five new Fe3+ and Cu2+-substituted Mo-enriched Dawson-type heteropolyanions as aqueous soluble potassium salts: α2-K7[Fe(OH2)P2W12Mo5O61] and α2-K7[Fe(OH2)P2W13Mo4O61], α1- and α2-K8[Cu(OH2)P2W12Mo5O61] and α2-K8[Cu(OH2)P2W13Mo4O61]. The substituted species as well as their immediate lacunary precursors were characterized by IR, UV/Visible and 31P NMR spectroscopy. In particular 31P NMR spectroscopy indicates that isomerically pure compounds were obtained. The activity of these chemicals in electrocatalysis is illustrated by the reduction of nitrite for Fe3+ derivatives and the reduction of nitrate for Cu2+ compounds. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)