The mixed-metal tris(disulfide) thiophosphate, KNb1.77Ta0.23PS10

Abstract

The title compound catena-poly[potassium [tri-μ-disulfido-μ-tetrathiophosphato-di[niobate(IV)/tantalate(IV)(0.885/0.115)]]], has been obtained through the reaction of the elements with KCl. The title compound is isostructural with KNb2PS10, with the Nb sites occupied by statistically disordered Nb (88.5%) and Ta (11.5%) atoms. The structure is composed of anionic ∞1[M2PS10]− chains along [100] (M = Nb/Ta) and K+ ions. This chain is built up from distorted bicapped trigonal prisms [MS8] and [PS4] tetrahedra. There are no interchain bonding interactions, except for electrostatic and van der Waals forces. The S22− and S2− anionic species and the M4+–M4+ pair [M—M = 2.8939 (3) Å] are observed. The classical charge balance is represented by [K+][M4+]2[PS43−][S22−]3.