The electronic structures of formally d7 transition metal sandwich complexes

INDO SCF calculations have been carried out for the d6 sandwich species FeCp2, CrBz2, CpCrCh, CpMnBz, [CoCp2]+, [MnBz2]+, [CpMnCh]+, and [CpFeBz]+ (Cp = π-C5H5, Bz = π-C6H6, Ch = π-C7H7), and for systems obtained therefrom by the addition of one further electron. For all complexes except CoCp2 the extra electron is predicted to lie in a dominantly ligand level and the species generated to be less stable than the corresponding d6 systems.