Chemical Speciation study of Ternary complexes of Zn(II)-Azelaic acid dihydrazide-L-Proline and Zn(II)-Azelaic acid dihydrazide-L-Lysine in aqueous medium

Abstract

Chemometric speciation study of ternary complexes containing Zn(II) with a non toxic and ditopic ligand L= Azelaic acid dihydrazide (AZDH) and X= α-amino acids (L - Proline and L – Lysine) of type [MmLlX xHh], (where m=1, 2; l=1; x=1, 2 and h= -2 to 5) in different ratios of M:L:X= 1:1:1, 1:2:1, 2:1:1and 2:1:2 was carried out using potentiometric method of data acquisition followed by chemometric modelling methods of analysis using SOPHD program and MINIQUAD-75 program. The stability constants of the ternary complexes were determined at 303± 0.1 K and 0.1M ionic strength. Best-fit chemical models were selected on the basis of statistical parameters like standard deviation (SD), U (sum of the residual squares in mass balance equations) and chi-square test etc. Zn(II)-AZDHLysine ternary complexes were found to be more stable due to side chain presence in the lysine. Comparitive stabilities of ternary complexes and binary species were evaluated quantitatively using  log K formulation.