Ionization energies of the cations of metallocene (M(C 5H 5) +2), their half-sandwich complexes MC 5H +5 and the bare transition-metal ions M + (M = Fe, Co, Ni)

Abstract

Charge stripping experiments indicate that in the reaction M + → M 2 + e − the doublycharged transition-metal ions M 2+ (M = Fe, Co, Ni) are formed in excited states. Introduction of one or two C 5H 5 ligands drastically reduces the Q min values of the reaction M(C 5H 5) + x → M(C 5H 5) 2+) x + e − (x = 1, 2) by at least 3.5 eV. The experimental findings support existing molecular orbital concepts of metallocene compounds.