Stability constants of mixed ligand complexes of lead(II) with 1-(aminomethyl) cyclohexane acetic acid and α-amino acids

Formation of binary and ternary complexes of lead(II) ions with 1-(aminomethyl) cyclohexane acetic acid and some biologically important α-amino acids, such as glycine, l-alanine, l-valine, l-leucine, l-isoleucine, l-phenylalanine and l-proline was investigated using the potentiometric technique at 32 °C. The properties of mixed ligands were investigated and discussed. The acidity constants of the ligands and their stability constants were determined in 50% (v/v) DMSO-water medium under experimental conditions. The ternary complex formation was found to occur in a stepwise manner. The stability of ternary complexes was investigated and compared with that of the corresponding binary complex in terms of the parameters, Δ log K and log X. The concentration distribution of various species formed in the mixed ligand systems was evaluated.