Spectroscopic study of the interaction of amino acids with copper(II) ions in aqueous solution

The interactions of copper(II) ions with some essential amino acids viz., L-leucine(Leu), L-glycylglycine (Gly.gly), L-methionine (meth), L-lysine (Lys) have been studied in aqueous solution at different temperatures by visible spectrophotometric method. The equilibrium constants of the process. [Cu(H2O)(4)](2+) + L = [Cu(H2O)(3)L](2+) + H2O (where L stands for the monodentate amino acid) have been determined and the thermodynamic parameters i.e., Delta G degrees, Delta H degrees and Delta S degrees have been calculated.