Study by high-temperature photoelectron spectroscopy of the electronic structure of the transition metal difluorides, CuF2 and ZnF2

Abstract

The He I and He II photoelectron spectra of ZnF₂ and CuF₂ have been recorded and interpreted with the aid of ab initio molecular orbital calculations and a configuration interaction method. In copper difluoride configurations derived from metal 3d and ligand 2p ionizations make significant contributions to the low-lying states of CuF₂⁺. In contrast, however, in the case of zinc difluoride the first four ionic states arise from F 2p ionization and are well separated from the ionic states arising from metal 3d ionization. All the evidence suggests that the 3d orbitals in CuF₂ are valence in character whereas in ZnF₂ they behave as core orbitals.