An X-ray photoelectron spectroscopy and quantum chemical study of copper(II) β-diketonates and Cu(HFA)2 complexes with imidazoline ligands

An X-ray photoelectron spectroscopy study of the charge and spin state of copper(II) β-diketonates and Cu(hfa)2 (hfa-hexafluoroacetylacetonate) complexes with imidazoline ligands is performed with comparison to the data of quantum chemical calculations. It is shown that the structure of the spectra of copper is described by a superposition of the |2p53d9> and | 2p53d10L> electronic states determined by electron transfer processes between copper and L ligand atoms. It is found that during the coordination of imidazoline ligands to the Cu(hfa)2 complex the spin density is redistributed through the chain of chemical bonds from the ligand nitroxyl group to the copper atom.