Discovery and Isolation of Two Arsenotungastate Species: [As₄W₄₈O₁₆₈]^36– and [As₂W₂₁O₇₇(H₂O)₃]^22–

Abstract

Two novel arsenotungstate species, [As₄W₄₈O₁₆₈]^36- (<b>1a</b>) and [As₂W₂₁O₇₇(H₂O)₃]^22- (<b>2a</b>), have been successfully isolated under a one-pot synthetic method. <b>1a</b> is the second largest arsenotungstate cluster and is constructed from four {AsW₁₂} clusters combined together. <b>2a</b> can be described as lacunary sites of {As₂W₁₉} filled by {W₂O₈} units. Compounds <b>1</b> and <b>2</b> exhibit proton conductivity properties, and the conductivity value of <b>1</b> is 5.0 × 10^-3 S cm^-1 at 98% relative humidity and 75 °C. This work proves that the lattice water molecules and polyoxoanions can participate in the formation of a hydrogen bond, acting as effective pathway for intermolecular proton conduction.