Synthesis and X-ray crystal structure of a selenophenoquinonoid-extended donor, BEDT–BDTS, affording highly conducting tetracyanoquinodimethaneand I3 complexes

Abstract

2,5-Bis(4,5-ethylenedithio-1,3-dithiol-2-ylidene)-2,5-dihydroselenophe++ne (BEDT–BDTS), a selenophenoquinonoid-extended analogue of bis(ethylenedithio)tetrathiafulvalenes (BEDT–TTF), has been synthesized as a promising candidate for an electron-donating component of highT_c organic superconductors. BEDT–BDTS is air-stable and has a significantly enhanced electron-donating ability compared with that of BEDT–TTF. The molecular and crystal structures of BEDT–BDTS have been determined by single crystal X-ray analysis in which short intermolecular SS contacts have been found in the side-by-side directions of the donor arrangements. A 1:1 TCNQ complex and a 3:1 I₃^– radical cation salt of BEDT–BDTS have been obtained and proved to exhibit fairly high room temperature conductivities.