THE CRYSTAL-STRUCTURES OF 3 PRECURSORS TO ORGANIC DONORS BASED ON BEDT-TTF

Three precursors to organic donors based on BEDT-TTF have been prepared, 2,3-dihydro-1,3-dithiolo[4,5-e][1,4]dithiin-6-thione (1), 2,3-dihydro-2-oxo-3-phenyl-1,3-dithiolo[4,5][1,4]dithiin-6-thione (2) and 2,3-dihydro-2-phenyl-1,3-dithiolo-[4,5-e][1,4]dithiin-6-one (3). The crystal structures have been determined from low-temperature X-ray diffraction data. They crystallize in monoclinic space groups as follows. Compound 1 in P2(1)/n with a = 10.600(2), b = 5.7887(8), c = 13.436(3) angstrom, beta = 93.03(2)-degrees, Z = 4; 2801 reflections gave R = 0.030. Compound 2 in P2(1)/c with a = 10.0792(13), b = 6.059(2), c = 20.578(5) angstrom, beta = 105.87-degrees, Z = 4; 2490 reflections gave R = 0.031. Compound 3 in C2/c with a = 15.735(13), b = 9.1996(9), c = 16.487(14) angstrom, beta = 96.85(3)-degrees, Z = 8; 3510 reflections gave R = 0.044. Compound 3 displays disorder of the ethylene group. The molecular geometries of these compounds are similar to those found in the salts of the related dimers BEDT-TTF. Short S-S intermolecular interactions influence the packing in 1-3. These interactions are comparable to and even shorter than those found in BEDT-TTF salts.