'Organic metals'. Isostructural tetrathia- and tetraselena-fulvalene salts of 2,5-diethyltetracyano-p-quinodimethane

Replacement of the sulphur atoms in the charge transfer salt tetrathiafulvalene (TTF)-2,5-diethyltetracyano-p-quinodimethane (DETCNQ) with selenium yields the isostructural and better conducting analogue tetraselenafulvalene (TSeF)-DETCNQ, in which the Peierls transition temperature is decreased.