The electronic structure of tricarbonyl(norbornadiene)iron. A semiempirical INDO MO study

Abstract

The electronic structure of tricarbonyl(norbornadiene)iron ( 1) in the ground state and in the cationic hole-states has been investigated by means of semiempirical INDO calculations. The bonding characteristics of 1 can be rationalized in terms of Hoffmann's fragment approach for the Fe(CO) 3 moiety. The vertical ionization potentials of 1 in the outer valence region are calculated by a perturbational expansion based on the Green's function formalism. The strong correspondence between calculated reorganization energies and the localization properties of the orbital wavefunction leads to a dramatic breakdown of Koopmans' theorem.