Ab Initio Study of Structural, Electronic and Magnetic Properties of TM&(B@C60) (TM = V, Cr) Sandwich Clusters and Infinite Molecular Wires

The geometrical structure, electronic and magnetic properties of B-endoped C-60 (B@C-60) ligand sandwich clusters, TM&(B@C-60)(2) (TM = V, Cr), and their one-dimensional (1D) infinite molecular wires, [TM&(B@C-60)](infinity), have been systematically studied using first-principles calculations. The calculations showed that the TM atoms can bond strongly to the pentagonal (eta(5)-coordinated) or hexagonal rings (eta(6)-coordinated) of the endoped C-60 ligands, with binding energies ranging from 1.90 to 3.81 eV. Compared to the configurations with contrast-bonding characters, the eta(6)- and eta(5)-coordinated bonding is energetically more favorable for V-(B@C-60) and Cr-(B@C-60) complexes, respectively. Interestingly, 1D infinite molecular wire [V&(B@C-60)-eta(6)](infinity) is an antiferromagnetic half-metal, and 1D [Cr&(B@C-60)-eta(5)](infinity) molecular wire is a ferromagnetic metal. The tunable electronic and magnetic properties of 1D [TM&(B@C-60)](infinity) SMWs are found under compressive and tensile stains. These findings provide additional possibilities for the application of C-60-based sandwich compounds in electronic and spintronic devices.