Interpretation and relation between chemical shift and percentage covalency of Cu(II) complexes with Schiff base ligand

The nature of the electronic structure and bonding in transition metal compounds is matter of intrinsic interest. High-energy spectroscopic are well suited to provide information on these points. Among them, X-ray absorption spectroscopy (XAS) has been revealed to be a potential tool for determining the electronic and geometrical structure of complex compounds. In particular, K edge and XANES spectra of transition metal complexes have been the topic of several studies. The position and shape of X-ray absorption discontinuities have been used to deduce structural and chemical bonding information on transition metal complexes. The K-absorption spectra were recorded on the synchrotron radiation, i.e., on beamline BL-8 at RRCAT, Indore . XANES reveal to identify the allowed transitions and also the mixing or splitting of the final state orbital. [1, 2] Using known structural data, informative deductions on structure-bonding relations have been made. copper K-edge XANES spectra have been used since they probe 1s→3d, 1s→4p transitions respectively. Since the spectra can be influenced by the state of the d orbital, which is primarily responsible for the bonding with ligands. For Cu-containing complexes, Cu K-edge XANES has been widely used to derive information on the electronic and geometrical structure.