STRUCTURES OF 4,5-BIS(METHYLTHIO)-3H-1,2-DITHIOLE-3-THIONE AND 1,2-DITHIOLE-3-THIONE-(5,4-B)-5,6-DIHYDRO-1,4-DITHIIN

4,5-Bis(methylthio)-3H-1,2-dithiole-3-thione, C5H6OS4 (BMDT), M(r) = 210.34, monoclinic, P2(1)/c, a = 8.975 (1), b = 14.727 (1), c = 13.151 (3) angstrom, beta = 93.46 (1)-degrees, V = 1735 (1) angstrom 3, Z = 8, D(m) = 1.62 (1), D(x) = 1.610 Mg m-3, lambda(Mo K-alpha) = 0.71073 angstrom, mu = 0.99 mm-1, F(000) = 864, T = 295 K, R = 0.033, wR = 0.051 for 3712 unique observed reflections with I > 2.5-sigma(I). 1,2-Dithiole-3-thione-[5,4-b]-5,6-dihydro-1,4-dithiin, C5H4S5 (DTDD), M(r) = 224.39, monoclinic, P2(1)/c, a = 12.099 (2), b = 17.613 (2), c = 8.201 (3) angstrom, beta = 108.43 (2)-degrees, V = 1658 (1) angstrom 3, Z = 8, D(m) = 1.79 (1), D(x) = 1.798 Mg m-3, lambda(Mo K-alpha) = 0.71073 angstrom, mu = 1.26 mm-1, F(000) = 912, T = 295 K, R = 0.044, wR = 0.044 for 3271 unique observed reflections with I > 2.5-sigma(I). The two BMDT molecules in the asymmetric unit have nearly identical bond lengths and bond angles, whereas the two symmetry independent DTDD molecules differ with respect to the -S-CH2-CH2-S fragment. The carbonyl O atom in BMDT and the thione S atom in DTDD are involved in rather short intermolecular contact distances probably due to delocalization of pi-electron density in the all-trans system (S,O) = [GRAPHICS]