Single-crystal structure of Cs2Re6S6Br8 rhenium thiobromide with acentric Re6 octahedral cluster units

Cs2Re6S6Br8 (trigonal, a = 10.001(5) angstrom, c = 14.676(5) angstrom) exhibits the same structure as Cs2Mo6Cl8Br6 and Cs2Mo6Br14 that were described in a noncentro-and centrosymmetric space groups, respectively. The structure has been refined in P31c space group from a single crystal of actual composition Cs1.95(1)Re6S5.82(3)Br8.19(3) close to the cesium-rich end of the solid solution Cs2Re6S6Br8 - CsRe6S5Br9. The centrosymmetry is respected by almost all the atoms of the asymmetric unit, but it is clearly broken by significant differences in the S/Br statistical distribution of the disordered "inner" ligands around the Re-6 cluster. Structural refinements from data collected at 100 K revealed that the Cs cation disorder is static. From the structure refinements, the stable isomers of the [Re6S6Br2] and [Re6S5Br3] cluster cores have been unambiguously determined.