Standard thermodynamic functions of complex formation between Cu2+ and glycine in aqueous solution

Heat effects of the interaction of copper(II) solutions with aminoacetic acid (glycine) are measured by the direct calorimetry at 298.15 K and ionic strengths of 0.5, 1.0, and 1.5 against a background of potassium nitrate. Standard enthalpy values for reactions of the formation of aminoacetic acid copper complexes in aqueous solutions are obtained using an equation with a single individual parameter by extrapolating it to zero ionic strength. The standard thermodynamic characteristics of complex formation in the Cu²⁺-glycine system are calculated. It is shown that glycine-like coordination is most likely in Cu(II) complexes with L-asparagine, L-glutamine, and L-valine.