Influence of Ionization and Spin Transitions on Electron Delocalization in the Molecules of Transition Metal Sandwich Complexes

Abstract

A quantum-chemical study of the structures of symmetric 3d metal sandwich complexes with benzene and cyclopentadienyl ligands has been carried out within the framework of the electron density of delocalized bonds (EDDB) model. Neutral and ionized molecules in various spin states were considered. It is shown that successive population of the d-electron shell by varying the metal atom in a series of similar complexes, as a rule, leads to a decrease in the degree of electron density delocalization. The detachment of an electron from neutral molecules also reduces the number of delocalized electrons in the sandwich system, butthe contribution of the metal atom to delocalization increases in most cases. Singlet-triplet transitions in metallocenes and bis-benzene complexes decrease the electron density of delocalized bonds, but to a lesser extent than in the free and C6H6 ligands.