Structures and physical properties of magnetic organic conductors based on bent donor molecule EDT-EDSe-TTFVS

Abstract The preparation, crystal structures, and physical properties of magnetic organic conductors based on a new bent donor molecule ethylenedithio-ethylenediseleno-tetrathiafulvalene-thioquinone-1,3-dithiolemethide (EDT-EDSe-TTFVS 3 ) are reported. The single crystals of 3 2 FeCl 4 (EtOH) and 3 2 FeBr 4 are obtained by the electrochemical oxidation of 3 in the presence of ( n -Bu 4 N)FeX 4 (X = Cl, Br) at 45 °C. Semiconducting behavior is observed with moderate conductivities of 4.0 and 0.6 S cm −1 for 3 2 FeCl 4 (EtOH) and 3 2 FeBr 4 , respectively. In the crystal structures of both salts, the donor molecules and magnetic FeX 4 − ions form segregated layers. Within the organic layer, the donor molecules form columnar stacks, and the intra-columnar intermolecular overlap integrals are larger than the inter-columnar ones, resulting in the quasi one-dimensional electronic structures. There are atomic close contacts between the donor and FeX 4 ion layers, which gives rise to the antiferromagnetic interaction of Fe(III) d -spins in both salts. Moreover, the Fe(III) d -spins in 3 2 FeBr 4 are subject to the antiferromagnetic ordering at 5 K due to the strong π– d and d–d interactions.