Crystal structures of 4,4′-(disulfane-1,2-diyl)bis(5-methyl-2H-1,3-dithiol-2-one) and 4,4′-(diselanane-1,2-diyl)bis(5-methyl-2H-1,3-dithiol-2-one)

The two title compounds, C8H6O2S6 and C8H6O2S4Se2, are isotypic with very similar cell parameters. The complete molecules constitute the asymmetric units, despite being chemically perfectly symmetric. The most prominant differences in the metrical parameters arise from the distinct sizes of sulfur and selenium in the dichalcogenide bridges, with C—S—S—C and C—Se—Se—C torsion angles of 70.70 (5) and 68.88 (3)°, respectively. The crystal packing is determined by weak non-classical hydrogen-bonding interactions. One carbonyl oxygen but not the other participates in C—H...O interactions zigzagging along the b axis, forming infinite chains. This is complemented by an intramolecular C—H...S interaction and further intermolecular C—H...S (C—H...Se) interactions, resulting in a three-dimensional network. The interactions involving the bridging chalcogenides form chains protruding along the c axis