3d Transition Metal-Metallofullerene-Ligand Molecular Wires: Robust One-Dimensional Antiferromagnetic Semiconductors

Abstract

The structures and properties of one-dimensional (1D) sandwich molecular wires constructed with altering 3d transition metal (TM) and the metallofullerene (TM@C60) entities, [TM&(TM@C60)]∞, are studied using density functional theory calculations. Different from the bonding character insensitivity to TM of previously reported 1D [TMBz]∞ and [TMCp]∞ analogues, the bonding characters of the investigated 1D [TM&(TM@C60)]∞ molecular wires depend heavily on the identity of metal elements. In 1D [TM&(TM@C60)]∞, molecular wires with early TMs like Ti and V, TM-η5 coordinate bonds are favored. In contrast, TM-η6 bonding conformations are energetically preferred for those with later TMs, for example, Cr–Ni. Bader charge analysis reveals that valence electrons are transferred from both encapsulated and sandwiched TM atoms to the C60 ligand. More importantly, all the molecular wires in ground states are robust antiferromagnetic semiconductors because of the peierls distortion of the configurations and the moderate binding energies. Therefore, the fabrication of endohedral metallofullerenes offers an effective route to regulate the magnetism and electronic properties of C60–ligand sandwich complexes.