Flux Crystal Growth, Crystal Structure, and Magnetic Properties of a Ternary Chromium Disulfide Ba₉Cr₄S₁₉ with Unusual Cr₄S₁₅ Tetramer Units.

ABSTRACT: A new ternary chromium disulfide, Ba₉Cr₄S₁₉, has been grown out of BaCl₂ molten salt. Single-crystal structure analysis revealed that it crystallizes in the centrosymmetric space group C 2/c with lattice parameters: a = 12.795(3) Å, b = 11.3269(2) Å, c = 23.2057(6) Å, β = 104.041(3)°, and Z = 4. Ba₉Cr₄S₁₉ comprises four face-sharing Cr-centered octahedra with disulfide ions occupying sites on each terminal face. The resulting Cr₄S₁₅ tetramer units are isolated by nonmagnetic Ba-centered polyhedra in the ab plane and barium disulfide (=Ba₄(S₂)₂) layers along the c-axis. Following the structure analysis, the title compound should be expressed as [Ba²⁺]₉[Cr³⁺]₄[(S₂)^2-]₄[S^2-]₁₁, 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.

SUBMITTER: Yan H 

PROVIDER: S-EPMC7970544 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature