Magnetism in Molecular Vanadium-Benzene Sandwiches

Abstract

The magnetic moments of the vanadium‐benzene sandwiches have been experimentally found to increase with the number of vanadium atoms in the molecule which suggests that the unpaired electrons on the metal atoms can couple ferromagnetically. We report on ab initio calculations of the equilibrium geometrical structures, electronic configurations and magnetic properties of complexes formed by vanadium and benzene, Vn(C6H6)n+1 (n < 5). Employing density functional theory, our results confirm the increase of the magnetic moment in the considered sandwiches with the number of V atoms that was found at higher temperatures (300 K). At lower temperatures, however for certain clusters (n = 3) an antiferromagnetic coupling can appear, that gives rise to a lower average moment in the cluster.