Organic metals and superconductors based on BETS (BETS = bis(ethylenedithio)tetraselenafulvalene)

The development of unprecedented magnetic organic metals and superconductors with novel electromagnetic properties produced by the interplay between π conduction electrons of organic layers and localized magnetic moments of the inorganic anions became one of the main targets in the field of chemistry of molecular conductors. Well-known achievements include the discoveries of a paramagnetic organic superconductor and a ferromagnetic metal. When using BETS molecules and typical magnetic anions such as FeCl4 - and FeBr4-, various types of new magnetic conductors including the first antiferromagnetic conductors were discovered. The existence of considerable π-d interactions in magnetic organic metals was proved. Furthermore, the conductors exhibiting unprecedented superconductor-insulator transitions and field-induced organic superconductors were also disclosed.