Conducting complexes of TTF and TSF derivatives fused with selenium-containing five-membered rings

Electrocrystallization of bis(ethylcneseleno)-tetrathiafulvalene (BES-TTF) and -tetraselenafulvalene (BES-TSF) gave a variety of radical cation salts which had high room-temperature conductivities (60-280 S cm−1) and displayed a metal-to-semiconductor (insulator) transition at low temperature. Among them, however, the ClO4− and AsF6− salts of BES-TSF remained highly conducting even at cryogenic temperature. An X-ray crystallographic analysis of (BES-TTF)2SbF6, revealed that the complex carries a considerably two-dimensional interactive electronic structure.