A potentiometric titration technique has been used to determine the stability constants of complexes of promazine in aqueous medium. The proton-ligand and metal-ligand stability constants of Fe (III), Cd (II), Pb (II), Cu (II) and Zn(II) metal ions with PMZ have been performed at different temperatures 2980K and 308 0K at 0.1 M ionic strength. The Metal ligand stability constants are determined by different Computational Methods. The thermodynamic parameters (ΔG, ΔH and ΔS) and the thermodynamic stability constants for all of the investigated complexes were determined potentiometrically.
