Structural Study of Cu(II):Glycine Solution by X-ray Absorption Spectroscopy

Abstract

This work investigated the Cu K-edged XANES spectra of copper(II) chloride aqueous solution mixed with glycine aqueous solution by varying Cu(II):Glycine molar ratio with the XANES spectra of standard reference of copper and starting solution of CuCl 2 . Structural changes in these solutions are probed by X-ray absorption near-edge structure (XANES) spectra recorded in the vicinity of the copper K-edge for various Cu(II):Glycine molar ratios and for different pH. Comparison of spectra recorded for low and high concentrations of CuCl 2 in the mixed solutions show rather different XANES profiles. Low concentration of CuCl 2 in the mixed solutions without pH adjustment give also different XANES profiles from those obtained at a pH adjusted to 5.0. This highlights the importance of controlling these parameters for a proper determination of the various forms of metal complexes present in the mixed solutions.