Oxidization states of metal atoms in linear bimetallic multi-sandwich molecules V(n)(FeCp2)(n+1) and magnetic moment enhancement mechanism of its 1D wire

Phys Chem Chem Phys. 2010 May 14;12(18):4555-9. doi: 10.1039/b927272k. Epub 2010 Mar 15.

Abstract

Using density functional theory calculations, we demonstrate that one-dimensional bimetallic molecular ferromagnets (FeCpMCp)(infinity) (M = Sc, Ti, V, Cr and Mn, Cp = cyclopentadienyl) exhibit significant enhancement in local and global atomic magnetic moments as well as relatively large spin-polarization energy as compared to their monometallic counterparts. These yield an unusual charge configuration for one of the wires: (Fe(0)Cp(-1)V(+2)Cp(-1))(infinity). Hückel's rule and double-exchange interaction model are used to illustrate the details of local charge transfer and long-range ferromagnetic order. We then propose a growth mechanism for V(n)(FeCp(2))(n+1) (n = 1-4) clusters, which is supported unambiguously with time-of-flight mass spectroscopy data.