Halogen substituted tetraselenafulvalene derivatives

The synthesis and electrochemical properties of di- and tetra-halogenated tetraselenafulvalene (TSF) derivatives are presented. The synthetic method involves an efficient formation of halogen substituted 1,3-diselenole-2-selones from readily available starting materials. Electrochemical crystallization afforded several radical cation salts, and, of them, the ClO 4 salt of the dimethyl-dibromo-TSF showed a high conductivity of 400 S cm -1 at room temperature and retained metallic down to ca. 90 K.