Flux Crystal Growth, Crystal Structure, and Magnetic Properties of a Ternary Chromium Disulfide BaCrS with Unusual CrS Tetramer Units.

A new ternary chromium disulfide, BaCrS, has been grown out of BaCl molten salt. Single-crystal structure analysis revealed that it crystallizes in the centrosymmetric space group 2/ with lattice parameters: = 12.795(3) Å, = 11.3269(2) Å, = 23.2057(6) Å, β = 104.041(3)°, and = 4. BaCrS comprises four face-sharing Cr-centered octahedra with disulfide ions occupying sites on each terminal face. The resulting CrS tetramer units are isolated by nonmagnetic Ba-centered polyhedra in the plane and barium disulfide (=Ba(S)) layers along the -axis. Following the structure analysis, the title compound should be expressed as [Ba][Cr][(S)][S], which is also consistent with Cr2p X-ray photoemission spectra showing trivalent states of the Cr atoms. The unique Cr-based zero-dimensional structure with the formation of these disulfide ions can be achieved for the first time in ternary chromium sulfides, which adopt 1-3 dimensional frameworks of Cr-centered polyhedra.