Potentiometric Study of Mixed Ligand Complexes of Sulphur Containing Ligands and Amino Acids with Zn(II)

Abstract

The pH-metric study of ZnAB mixed ligand system [A = mercaptosuccinic acid (MSA), 2- mercaptopropionylglycine (2-MPG) and B = glycine (gly), alanine (ala), valine (val), cysteine (cys) and penicillamine (pen)] in aqueous solution at 26 ± 0.5ºC and 0.1 M (NaClO₄) ionic strength shows the presence of mixed ligand complexes. In ZnAB complexes five-membered rings are formed due to the coordination of ligands with metal. The value of Δ log K shows the preferential formation of ternary complexes.