Pentapotassium μ-arsenato-bis(hydroxytetramolybdate) dihydrate

Abstract

The title arsenatomolybdate, K5[Mo8O24(OH)2(AsO4)]·2H2O, which was obtained hydrothermally, features an [AsMo8O28(OH)2]5− anion, which is formed by two Mo4O14(OH) units that are linked by As in a sandwich-like fashion. The overall symmetry of the anion is m2m. The {Mo4O14(OH)} core is composed of two pairs of confacial bioctahedral {Mo2O9} units with two μ4-O atoms which have been characterized as hydroxyl groups. The anions are further interconnected by potassium cations, forming a three-dimensional network structure with the uncoordinated water molecules occupying the channels. The structure is further stabilized by O—H...O hydrogen bonding.