Formation of Glycinate Complexes of Iron(II) in Solutions of Different Ionic Strengths

Abstract

Processes of complexation in the Fe(0)–Fe(II)–glycine–Na(H)ClO4–H2O system at a temperature of 298.15 K, an ionic strength of solutions of 0.1–1.0 (NaClO4), СFe(II) = 1 × 10−3, and in the pH range of 0.8–8.0 are studied according to the Clark–Nikolsky oxidation potential. Experimental curves are obtained for the dependences of EMF on concentration, рН, pCFe(II), рСHL. Successive approximation of theoretical and experimental oxidative potential functions is used to calculate the constants of complexation. The dependence of the constant of complexation on the ionic strength of the solution is calculated on the basis of the Debye–Huckel theory. It is found that the formation constants of coordination compounds fall as the ionic strength of a solution rises.