Bis[4-(trimethylammonio)phenyl] disulfide diiodide acetone solvate

The title compound, C(18)H(26)N(2)S(2)(2+).2I(-).2C(3)H(6)O, is an intermediate in the design of the zwitterionic thiolate 4-(trimethylammonio)benzenethiolate (Tab), in which a pair of aryl-substituted S atoms are linked by a covalent bond. The central S-S bond length is 2.020 (3) A and the C(ar)-S-S-C(ar) torsion angle is -84.1 (2) degrees . The crystal structure is stabilized by nonclassical hydrogen bonds which occur as intramolecular C-H...I interactions and intermolecular C-H...S and C-H...O contacts. In the crystal structure, both the dication and the two symmetrically independent iodide counter-anions are located on twofold crystallographic axes, whereas the acetone solvent molecule occupies a general position.