Crystal structure of the mixed-metal trisulfide BaCu1/3Ta2/3S3

Abstract

The mixed-metal title compound, BaCu1/3Ta2/3S3 [barium copper(II) tantalum(V) trisulfide], was prepared through solid-state reactions. The crystal structure adopts the BaTaS3 structure type and consists of face-sharing [MS6] (M = Ta,Cu) octahedra (point-group symmetry -3m.) that are condensed into infinite chains along [001]. Adjacent chains are linked through the barium cations (site symmetry -6m2), which exhibit a coordination number of twelve. The M site is occupied by 2/3 of TaV and 1/3 of CuII, whereby the average M - S distances are slightly longer than those of ordered BaTaS3. The classical charge balance of the title compound can be represented by [Ba2+] [(Ta/Cu)4+] [S2-]3.