Speciation of Binary Complexes of Co(II), Ni(II) and Cu(II) With Bidentate Ligand in Low Dielectric Medium

Abstract

Speciation of binary complexes of Co(II), Ni(II) and Cu(II) with Ethylenediamine in (0?60% v/v) Dioxan (Dox)-water mixtures was studied pH-metrically at 303?0.1 K and at an ionic strength of 0.16 mol L-1. The models contained ML, ML2 and ML3 species for Co(II), Ni(II) and Cu(II). The trend in the variation of stability constants with Dox content was explained on the basis of electrostatic and non electrostatic forces. Distribution of the species with pH at different compositions of Dox-water media was also presented.