X-ray photoelectron spectroscopy of copper compounds

TLDR

X‑ray photoelectron spectra were measured for about 46 copper compounds and complexes. The study found that copper and ligand binding‑energy shifts depend on oxidation state, ligand type, and number, and that satellite line splitting in the 2p and 2s bands correlates with binding energies, explained by a 3d→4s,4p shake‑up mechanism.

Abstract

The X-ray photoelectron spectra of some forty-six copper compounds and complexes have been measured. The chemical shifts obtained from accurate determinations of the binding energies have been qualitatively explained on the basis of the Pauling electronegativity concept using the group electronegatives of Huheey for the polyatomic counter anions. The chemical shifts of the copper atoms as well as the atoms in the ligands were found to be dependent not only on the oxidation state but also on the kind and number of ligand atoms. Intense satellite lines were found in the 2p and 2s bands of the cupric compounds; the number and splitting of the satellites were found to be sensitive to the chemical environment. A correlation was found between the satellite splitting and the binding energies and this is explained by a 3d→4s, 4p 'shake-up' mechanism.