STRUCTURE OF 3,3'-HEXAMETHYLENEDITHIO-4,4'-DI-P-TOLYLTETRATHIAFULVALENE HEMIBENZENE SOLVATE

C26H26S6.1/2C6H6, M(r) = 569.94, monoclinic, C2/c, a = 28.454 (4), b = 10.524 (1), c = 19.337 (8) angstrom, beta = 98.63 (3)degrees, V = 5725.2 angstrom 3, Z = 8, D(x) = 1.32 Mg m-3, lambda(Mo K-alpha) = 0.71073 angstrom, mu = 0.475 mm-1, F(000) = 2392, room temperature, final R = 0.039 for 2389 observed reflections. The compound is in a cis configuration. The striking stereo-chemical molecular feature is the presence of a crown-type configuration which includes the tetrathiafulvalene (TTF) fragment. In order to adjust to this necklace configuration the latter distorts severely from planarity. Folding occurs around the sulfur-sulfur axis of each five-membered ring leaving three essentially planar moieties at dihedral angles of 46.6 and 34.4-degrees. The two five-membered rings have an envelope conformation leading to an overall boat conformation for the TTF moiety. The conformation of the alkyl fragment of the crown is sc(synclinal)-ap(antiperiplanar)-ap-sc-sc-ap-sc. The shortening of the C(sp3)-C(sp3) bond distances toward the middle of the alkyl chain in the crown [range 1.473 (7)-1.545 (7) angstrom] is probably due to the large thermal motion of C(7) and C(8) atoms involved in the bond. There are no intermolecular contacts shorter than normal van der Waals distances.