Coordination mode in the binary systems of copper(II)/O-phospho-L-serine

Abstract

Results of equilibrium and spectral studies have shown that in the O-phospho-L-serine (Ser-P) with copper(II) system the complexes MHL, ML, ML2 and ML(OH) x are formed; overall stability constants of the Cu(II) species have been determined. Coordination mode in the complexes was concluded on the basis of spectral investigation (NMR, 31P NMR, 1H–15N NMR, IR, EPR and Vis). In the Cu/phosphoserine system at low pH, coordination mainly involves the phosphate group. At higher pH, the efficiency of– is low and coordination is by the amine and carboxyl groups. Differences in the coordination mode in the phosphoserine complex at low pH, compared to those of endogenic serine, in their reactions with copper(II) ions have been observed.