Formation constants of ternary complexes of some bivalent metal ions with schiff base as primary ligand and O-, O-; N,O– or N,N donor as a secondary ligand

Abstract

Formation constants of ternary complexes of Cu(II), Ni(II), Co(II), Zn(II) and Cd(II) with 2-[{(¹H-benzimidazol- 2-ylmethyl)imino}methyl]phenol (BMIMP) as primary ligand and glycine, β-alanine, ethylenediamine, 1,3-diaminopropane, catechol and salicylic acid as secondary ligands have been determined <em>p</em>H-metrically in 60% (v/v) aq. methanol at 30°C and <em>1=</em>0.1 <em>M</em> (NaClO₄). The comparison of Dlog <em>K </em>and percentage of relative stabilisation [(%) R.S.] values reveals that the order of stability of ternary complexes with respect to the secondary ligands in terms of donor atoms is 0 O^-, O^-; N,O^– or N,N; the order with respect to the metal ions is in conformity with Irving-Williams natural order of stabilities.