Photoelectron spectroscopy of Ce(η-C5H5)3 - Accessing two ion states on 4f ionization

PE spectroscopy of Ce(η-C5H5)3 provides evidence that the ground state of the [Ce(η-C5H5)3]+ cation is described as a mixture of two configurations of 1A1 symmetry, one with no 4f electron, Lf0and one with a single 4f electron interacting strongly with a hole of the same symmetry in the ligand shell, L−1f1.