First salt of bis(ethylenedithio)tetrathiafulvalene containing mono- and dications

Abstract

The radical-cation salts of bis(ethylenedithio)tetrathiafulvalene (ET) hold interest since many of these species are organic metals and some are superconductors [i, 2]. We have synthesized a series of salts of ET with metal complex anions, (MX~) =-, where M = Zn, Mn, Co, and Cd and X = CI, Br having different physical properties. Among these compounds, we have found the salt (ET)3(ZnCI~) 2, which holds interest not so much for its physical properties but in light of the circumstance that it contains the previously undescribed ET 2+ dication. Crystals of this salt were obtained by the electrochemical oxidation of 0.002 mole/liter ET in benzonitrile on a platinum anode using direct current of 2 ~A at 80~ We used 0.005 mole/liter (Bu4N)2(ZnCI~) as the electrolyte.