Equilibrium studies on ternary Cu(U) complexes containing tripolyphosphate, pyrophophate or adenosine-5' -triphosphate and a series of secondary ligands

407-411Ternary metal complexes of the type MLA where M = Cu(II); L= tripolyphosphate (TPP), pyrophosphate (PP) or adenosine-5'-triphosphate (ATP) and A= alanine, serine, methionine, phenylalanine, tryptophan, histidine, aspartic acid, ethylenediamine, 2,2'-bipyridyl, 1,10-phenanthroline, malonic acid and pyrocatechol have been investigated potentiometrically at 35°C and I=0.2 mol dm-3 (KNO3). The stabilities of the ternary metal complexes have been quantitatively compared with the stabilities of the corresponding binary metal complexes(MA) determined under identical experimental conditions Ternary complexes containing PP or ATP are found to be more stable than the corresponding complexes containing TPP. Various factors leading to differences in the relative stabilities of the ternary complexes are discussed