Crystal structure of the mixed-metal thiophosphate Nb1.18V0.82PS10

Abstract

The mixed-metal thiophosphate, Nb1.18V0.82PS10 (niobium vanadium phosphorus decasulfide), has been prepared though solid state reactions using an alkali-metal halide flux. The title compound is isostructural with two-dimensional Nb2PS10. [M2S12] (M = Nb or V) dimers built up from two bicapped trigonal prisms and tetrahedral [PS4] units share sulfur atoms to construct 1∞[M2PS10] chains along the a axis. These chains are linked through the disulfide bonds between [PS4] units in adjacent chains to form layers parallel to the ab plane. These layers then stack on top of each other to complete the three-dimensional structure with van der Waals gaps. The M sites are occupied by 59% of Nb and 41% of V and the average M—S and M—M distances in the title compound are in between those of V2PS10 and Nb2PS10. The classical charge balance of the title compound can be represented by [(Nb/V)4+]2[P5+][S2−]3[S−]7.

Keywords

• crystal structure
• mixed-metallic thiophosphates
• layered structure