R. P. Phase, A. G. Shankarwar, S. G. Shankarwar and T. K. Chondhekar
The stability constant of (1:1:1) ternary chelates of bivalent zinc (II) metal ion with some biomolecules (drugs) such as aspartame (L4) and ethambutol hydrochloride (L7) as primary ligands and amino acids, such as Leucine (R3) and phenylalanine (R6) as secondary ligands have been carried out in 20% (v/v) ethanol - water medium pH-metrically at 300C and 0.1 M (NaClO4) ionic strength. The stability constants of binary complexes ML and ML2 are also determined under similar experimental conditions. The stability constants of ternary complexes are evaluated and their relative stabilities compared to the corresponding binary complexes are expressed in terms of statistical parameters Δlog K, KR, KL and Kr. Formation of complex species with respect to pH have been discussed by Irving- Rossotti technique and evaluated by using the computer SCOGS program
