Syntheses, structures, and electroconductivity of bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) and bis(methylenedithio)tetrathiafulvalene (BMDT-TTF) salts with cobalt 8,8′-dichloro-3,3′-bis(1,2-dicarbollide)

Radical cation salts of bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) and bis(methylenedithio)tetrathiafulvalene (BMDT-TTF) with the 8,8'-dichloro derivative of cobalt bis(1,2dicarbollide) (BEDT-TTF)2[8,8'-Cl-2-3,3'-Co(1,2-C2B9H10)(2)] (1) and (BMDT-TTF)(4)[8,8 Cl-2-3,3'-Co(1,2-C2B9H10)(2)] (2) were synthesized and their crystal structures and electroconducting properties were determined. The synthesized radical cation salts are semiconductors with the conductivity sigma(293) = 1.5 and 2.0 Ohm(-1) cm(-1), respectively. A decrease in the size of the substituent in a series of (BEDT-TTF)(2)[8,8'-X-2-3,3'-Co(1,2-C2B9H10)(2)] and (BMDT-TTF)4[8,8'-X-2-3,3'-Co(1,2-C2B9H10)(2)] (X = I, Br, Cl) results in the compression of the anion sublattice of the crystal and compaction of the radical cation packing of the conducting layer, which, in turn, increases the conductivity of the crystals.