Theoretical Study on Sandwich-Like Transition-Metal–Cyclooctatetraene Clusters and One-Dimensional Infinite Molecular Wires

[Image: see text] Using density functional theory calculations, we investigated the structure and electronic properties of cyclooctatetraene (C(8)H(8), COT)-ligand mono- or bi-transition-metal (M) sandwich clusters, M(n)(COT)(n+1) (M = Sc, Ti, Cr, Mn, n = 1, 2) or (COT)M(1)(COT)M(2)(COT), as well as their one-dimensional infinite molecular wires. All the sandwich M–COT clusters and molecular wires are rather stable with their binding energies ranging from 3.20 to 7.48 eV per transition-metal atom. Superior to M(n)Bz(n+1) complexes, most sandwich M–COT complexes are in their high spin states with ultrahigh magnetic moments. Moreover, one-dimensional infinite molecular wires, [Cr(COT)](∞), [(COT)V(COT)Ti](∞) and [(COT)Sc(COT)Cr](∞), are predicted to be ferromagnetic half-metals. Our findings suggest that such M–COT sandwich complexes may be potential candidates for applications in spintronics.