Novel organic metal of α-(BETS)2Cu5I6 with a two-dimensional polymeric anion network; synthesis, structure and properties

Abstract

The α-(BETS) ₂ Cu ₅ I ₆ radical cation salt was obtained by electrocrystallization and its crystal structure has been determined by single crystal X-ray diffraction. The salt has a layered crystal structure and shows an unusual two dimensional polymeric anionic network. Crystal resistance and optical properties were studied. At ambient pressure the electrical conductivity of this salt shows metallic behaviour down to 25-30 K and then an M-I transition takes place. It was found this transition was completely suppressed at pressures above ca. 10 kbar. After release of pressure the salt shows metallic behaviour down to 1.3 K.