Molecular metals with ferromagnetic interaction between localized magnetic moments

New charge-transfer salts (EDO-TTFI2)(2)M(mnt)(2) (M = Ni, Pt) are the first organic metals with strong ferromagnetic interactions. These salts consist of one-dimensional chains of EDO-TTFI2 donors and M(mnt)(2) accepters aligned 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 ferromagnet, which interact with conduction electrons. The origin of the ferromagnetic interactions are orthogonality of the molecular orbitals of M(mnt)(2) and spin polarization effect which is explained by McConnell's first model. (C) 2000 Published by Elsevier Science Ltd.