Synthesis, characterization and crystal structure of dicesium bis(1,2-dithiole-3,5-dithiolato-4-yl)disulfide

Dicesium bis(1,2-dithiole-3,5-dithiolato-4-yl)disulfide, 3, was obtained by aerial oxidation of dicesium 1,3-dithiole-3-thione-4,5-dithiolate in aqueous ethanol. The dianion in 3, in the 4e special positions of the space group Pbcn, lies on a crystallographic twofold axis and has, therefore, C2 molecular symmetry. As a consequence the asymmetric unit consists of, in addition to one cesium atom, precisely one half of the anion. The negative charges of the dianion are sustained by 1,3-dithiolate groups. The cesium atom has 11 nearest sulfur atoms with CsS distances in the range 3.5762(11)–4.1383(11) Å, from five different anions and as a result provides complete three-dimensional connectivity throughout the structure. The vibrational spectra of 3 and related compounds, including dicesium 1,3-dithiole-3-thione-4,5-dithiolate are presented as are RHF calculations on [dmt]2− and [dmt–dmt]2− species.