Magnetic and transport properties of organic radical ion salts containing tetrahalogenoferrate anion

A molecular antiferromagnet (TN = 4 K) crystal TMTSF·FeCl4 was prepared, in which antiferromagnetic interaction between localized spins on tetrachloroferrate anion are mediated by π-electrons on donor molecules. By contrast, in BMDT-TTF(MT)·FeCl4 crystal, d-spins and π-electrons are magnetically isolated from each other.