Synthesis and preliminary characterization of new conducting salts derived from bis(ethylenedithio)tetraselenafulvalene (BETS)

Nine new conducting salts of BETS have been synthesized by electrocrystallization. The resistivities of these materials have been monitored to low temperatures. The resistivities of α-(BETS)2MHg(SCN)4 (M = NH4 and K), which are isostructural with well known BEDT-TTF (ET) compounds, decrease smoothly and monotonically from room temperature to 0.4 K, but neither are superconductors. X-ray structural data are reported.