K absorption spectral studies of mixed ligand copper complexes with imidazole as one of the ligands

Abstract

The copper K absorption spectra of nine copper(II) mixed ligand complexes with imidazole (ImH) as primary ligand have been recorded in the X-ray absorption near edge structure (XANES) region using 400 mm Cauchois spectrograph. The various parameters determined were position of inflection point of the absorption edge, principal absorption maximum and edge-width. The data for chemical shift of the absorption edge have been interpreted to yield the effective nuclear charge and the oxidation state of the metal ion in the complexes. The edge-widths have been correlated with the coordination geometry of the complexes. The main absorption edge has been found to split into two components and this has also been explained. The present results have been compared with those reported earlier from chemical studies. The effects of variation of the secondary ligands on the various parameters have also been discussed.