(TM)2X organic superconductors: prototypes of one-dimensional conductors

Abstract Organic superconductivity has been discovered in 1979 in the one-dimensional organic conductor (TMTSF) 2 PF 6 . This discovery has to be considered in the framework of a long quest for new superconductors which started 15 years earlier with the suggestion made by W. Little for a new pairing mechanism in organic conductors. The extensive studies carried out over the last 20 years have revealed the existence of a vast series of isostructural compounds, (TM) 2 X , exhibiting signatures of a non-Fermi behavior at high temperature and a variety of ground states at low temperature. Besides superconductivity, low dimensional organic conductors have brought a wealth of new concepts in physics.