Computation of multimetalmultiligand complex formation equilibria in aqueous medium involving glutamic acid as primary ligand and Uracil as secondary ligand

Metallic complexes of multimetal and multiligand systems are complicated for calculating equilibrium concentrations in solution. Complexation equilibria have been deduced on the basis of speciation curves obtained through SCGOS computer program. The formation constants of ternary(1:1:1) quaternary(1:1:1:1) complexes of CuII, PbII, HgII, CdII, ZnII, CoII and NiII with Glutamic acid(A) and Uracil(B) as ligands have been determined potentiometrically in aqueous medium.Study of metal complexes of said ligands with respect to their stability, solution structure and quantitative aspects has been done. Acid dissociation constants of the ligands used and the formation constants of the ternary and quaternary complexes were determined at 37±1°C and in ionic strength I = 0.1 M NaNO3. Different concentration of species as a function of pH was examined and sequence of overall stability constants for MA, MB, MAB and M₁M₂AB type of complexes have been discussed which seem to follow Irving William order.