Improved Synthesis of Double‐Bridged Tetraselenafulvalenophanes and Formation of Their Conductive Radical Cation Salts

The double-bridged tetraselenafulvalenophanes (TSF-phanes, 4) were efficiently synthesized by a new method using the deprotection/realkylation sequence of the TSF bisthiolate building block 7. Electrocrystallization of 4b with the Au(CN)2− counter-anion gave a radical cation salt that showed a very high conductivity of 53 S cm−1 at room temperature. X-ray crystallographic analysis revealed that the crystal structure contained many intra- and intermolecular Se−Se contacts; favorable for high conductivity.