Molecular metals with ferromagnetic interaction between localized magneticmoments

New charge-transfer salts (EDO-TTFI2)(2)M(mnt)(2) (M = Ni, Pt) are the firs t organic metals with strong ferromagnetic interactions. These salts consis t of one-dimensional chains of EDO-TTFI2 donors and M(mnt)(2) accepters ali gned in parallel to each other. The metallic conductivity is due to the one dimensional chain of EDO-TTFI2, and a metal-insulator transition occurs at about 90 K. Localized spins of M(mnt)(2) behave as a one-dimensional ferro magnet, which interact with conduction electrons. The origin of the ferroma gnetic interactions are orthogonality of the molecular orbitals of M(mnt)(2 ) and spin polarization effect which is explained by McConnell's first mode l. (C) 2000 Published by Elsevier Science Ltd.