Molecular orbital-theoretical studies of a dinuclear Fe(II)-Fe(III) complex

摘要

A qualitative molecular orbital (MO) model for a dinuclear Fe(II)-Fe(III) complex 2, which can be considered as two edge-sharing octahedra, is evaluated on the basis of Extended-Huckel (EH) calculations. The MO picture derived is compared to the MO scheme suggested for a valence-delocalized Fe(II)-Fe(III) complex 1 studied recently, which represents two face-sharing octahedra. This comparison indicates that the iron-iron interaction plays an important role in 1 while this interaction is weaker in 2. In both molecules valence delocalization is provided by an in-phase combination of iron-d-orbitals of #sigma#-type with non-negligible ligand admixtures. The stronger intermetal coupling in 1 is mainly caused by the shorter iron-iron distance.