Synthesis, X-ray structure and molecular orbital study of a radical cationsalt of a S-position isomer of an EDT-TTF derivative: C.I-3 where C=6,7-dimethylsulfanyl-2,3-(dithiabutane-1,4-diyl)tetrathiafulvalene

The X-ray crystalline structure at 293 K and 150 K of the radical cation sa lt (C10H10S8I3) obtained from a disulfide tetrathiafulvalene (TTF) derivati ve, is described. The title compound crystallizes in the P1 space group wit h the lattice constants at 293 K: a = 9.7634(12) Angstrom, b = 9.9311(13) A ngstrom, c = 12.780(2) Angstrom, alpha = 72.94(1)degrees, beta = 74.51(1)de grees, gamma = 63.08(3)degrees, V = 1043.1(6) Angstrom(3), Z = 2. The struc tural study at low temperature indicates a similar crystal structure withou t any apparent symmetry and structural modifications. Donors are stacked in a zig-zag mode along a-axis with a strong dimerizatio n, confirmed by the molecular orbital calculations, The structural particul arity of the new pi-donor C engaged in the described salt bring the termina l disulfide bridge, we discuss here the influence of outer sulfur atoms on the structural organization.