Radical cation salts of BEDT-TTF, enantiopure tetramethyl-BEDT-TTF, and TTF-Oxazoline (TTF-Ox) donors with the homoleptic TRISPHAT anion

Abstract

The synthesis and crystal structures of five radical cation salts based on the organic donors bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF), racemic ethylenedithio-methyl-oxazoline-tetrathiafulvalene (EDT-TTF-MeOx) and the enantiopure (S,S,S,S) and (R,R,R,R) tetramethyl-bis(ethylenedithio)tetrathiafulvalene (TMBEDT-TTF) and the D₃-symmetric anion tris(tetrachlorobenzenediolato)phosphate(V) (TRISPHAT) are reported. The salts are formulated as [BEDT-TTF][(rac)-TRISPHAT]·CH₂Cl₂ (1), [BEDT-TTF][(rac)-TRISPHAT]·2CH₃CN (2), [(rac)-EDT-TTF-Ox][(rac)-TRISPHAT]·CH₃CN (3), [(S,S,S,S)-TMBEDT-TTF][(rac)-TRISPHAT]·2CH₃CN (4), and [(R,R,R,R)-TMBEDT-TTF][(rac)-TRISPHAT]·2CH₃CN (5). The donors are fully oxidized and self-assemble in dyads inserted in the channels generated by the packing of the TRISPHAT anions. Magnetic and EPR measurements performed on compounds 1 and 2 clearly indicate weak interactions within the dimers in compound 1, characterized by a very narrow line in the EPR spectrum, while the radicals are strongly coupled in compound 2.