Stability of binary complexes of L-aspartic acid in dioxan–water mixtures

Abstract

Speciation of binary complexes of Co(II), Ni(II) and Cu(II) with L-aspartic acid  in (0–60% v/v) 1,4-dioxan (Dox)-water mixtures was studied pH metrically at 303±0.1 K and at an ionic strength of 0.16 M. The models contained ML, ML_2, ML₂H₂, ML₂H₃ and ML₂H₄ species. 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.

KEY WORDS: Binary complexes, Stability constants, Aspartic acid, Speciation, Dioxan

Bull. Chem. Soc. Ethiop. 2013, 27(3), 367-376.

DOI: http://dx.doi.org/10.4314/bcse.v27i3.5