Equilibrium studies on transition metal binary and ternary complexes containing N-hydroxyphthalimide and other ligands in solution

摘要

The formation constants of binary, ML, ML_2 and ternary, MAL complexes where, M = Co(Ⅱ), Ni(Ⅱ); Cu(Ⅱ) and Zn(Ⅱ); L = N-hydroxyphthalimide (2-hydroxy-1,3-iso indoledione) and A = alanine, valine, ethylenediamine, 2,2'-bipyridyl, oxalic acid and catechol have been determined from solution equilibrium studies by pH-metric method at 30℃ and 0.1 M (KNO_3) ionic strength. The relative stabilities of the ternary complexes are quantitatively expressed in terms of the statistical parameter, Δlog K. The results are discussed in the light of both statistical and various astatistical factors. The stabilities of both the binary and ternary complexes were found to follow the Irving-Williams (natural) order.