XPS photoelectron lines, satellite structures and Wagner plot of Cu(II) β-diketonato complexes explained in terms of its electronic environment

Abstract

A series of copper(II) β-diketonato complexes [Cu(R1CHCOCHR2)2], with R1 = R2 = C6H5 (1); R1 = C6H5 and R2 = CH3 (2); R1 = R2 = CH3 (3); R1 = C6H5 and R2 = CF3 (4); R1 = CH3 and R2 = CF3 (5) and R1 = R2 = CF3 (6), was subjected to a systematic XPS study of the Cu 2p core-level photoelectron lines, their satellite structures and the LMM Auger lines. The binding energies of the main Cu 2p core-level photoelectron lines are sensitive towards chemical environment (initial state effects) and are described by linear correlations with the combined Gordy scale group electronegativity of the R-groups on the β-diketonato ligands, ΣχR, and the first electrochemical reduction potential, Epc, of the Cu compounds. The modified Auger parameters were determined from the constructed Wagner plot of the copper(II) β-diketonato complexes, which also showed that the initial state effects are dominant during the photoemission process.