Crystal structure of bis(ethylenedithio)tetrathiafulvalenium μ2-acetato-bis[tribromidorhenate(III)] 1,1,2-trichloroethane hemisolvate

Abstract

The asymmetric unit of the title salt, (C10H8S8)[Re2Br6(CH3COO)]·0.5C2H3Cl3, contains one bis(ethylenedithio)tetrathiafulvalene (ET) radical cation, one μ2-acetato-bis[tribromidorhenate(III)] anion and a 1,1,2-trichloroethane molecule with half-occupancy disordered about a twofold rotation axis. The tetrathiafulvalene fragment adopts an almost planar configuration typical of the ET radical cation. The C atoms of both ethylenedithio fragments in the cation are disordered over two orientations with occupancy factors 0.65:0.35 and 0.77:0.23. In the anion, six Br atoms and a μ2-acetate ligand form a strongly distorted cubic O2Br6 coordination polyhedron around the Re2 dinuclear centre. In the crystal, centrosymmetrically related ET cations and Re2O2Br6 anions are linked into dimers by π–π stacking interactions [centroid-to-centroid distance = 3.826 (8) Å] and by pairs of additional Re...Br contacts [3.131 (3) Å], respectively. The dimers are further packed into a three-dimensional network by non-directional interionic electrostatic forces and by C—H...Br and C—H...S hydrogen bonds. The disordered 1,1,2-trichloroethane molecules occupy solvent-accessible channels along the b axis.

Keywords

• crystal structure
• radical cation salt
• bis(ethylenedithio)tetrathiafulvalene
• rhenium
• quadruple metal–metal bond