4,5-Bis[(triorganotin)thiolato]-1,3-dithiole-2-thione, (R3Sn)2(dmit), 4,5-bis[(triorganotin)thiolato]-1,3-dithiole-2-one, (R3Sn)2(dmio), compounds: Crystal structures of (cyclohexyl3Sn)2(dmio), (Ph3Sn)2(dmit) and (Ph3Sn)2(dmio)

The synthesis and crystal structures of 4,5-bis[(triorganotin)thiolato]-1,3-dithiole-2-thione, (R3Sn)2(dmit), 1, and 4,5-bis[(triorganotin)thiolato]-1,3-dithiole-2-one, (R3Sn)2(dmio), 2, compounds are reported. Compounds, (1 or 2: R = Ph or cyclohexyl, Cy), have been obtained from reaction of R3SnCl with Cs2dmit or Na2dmio. The presence of the two tin centres in (2: R = Ph) is shown in the 13C NMR spectrum by the couplings of both Sn atoms to the dmio olefinic carbons with J values of 29.4 and 24.7 Hz. The δ119 Sn values for (1: R = Ph) and (2: R = Ph) differ by about 30 ppm, values being −20.7 and −50.1 ppm, respectively, in CDCl3 solution. X-ray structure determinations for (1: R = Ph) and (2: R = Ph or Cy) reveal the compounds to have 4-coordinate, distorted tetrahedral tin centres. The dithiolato ligands, dmit and dmio, act as bridging ligands, in contrast to their chelating roles in R2Sn(dmit) and R2Sn(dmio). A further difference between R2Sn(dmit) and R2Sn(dmio), on one hand, and 1 and 2 on the other, is that intermolecular Sn–S and Sn–O interactions are absent in 1 and 2. However, weak intermolecular hydrogen bonding interactions are found in (1: R = Ph) [C–H⋯π] and in (2: R = Ph) [C–H⋯π and C–H⋯O].