Sodium Ionophore III as Very Effective Receptor for Trivalent Europium and Americium

Abstract

Solvent extraction of micro amounts of europium and americium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H+B−) in the presence of Sodium ionophore III (L) was investigated. The equilibrium data were explained assuming that the species HL+, $$ \text{HL}_{2}^{ + } $$ , ML3+, $$ \text{ML}_{\text{2}}^{{\text{3} + }} $$ , and $$ \text{ML}_{\text{3}}^{{\text{3} + }} $$ (M3+ = Eu3+, Am3+; L = Sodium ionophore III) are extracted into the organic phase. The values of extraction and stability constants of the cationic complex species were determined in nitrobenzene saturated with water. It was found that the values of the stability constants of the corresponding complexes $$ {\text{EuL}}_{n}^{ 3+ } $$ and $$ {\text{AmL}}_{n}^{ 3+ } $$ , where n = 1, 2, 3 and L is Sodium ionophore III, in water-saturated nitrobenzene are comparable. Finally, it was proven experimentally that in the considered nitrobenzene medium, the investigated Sodium ionophore III ligand is a very effective receptor for the Eu3+ and Am3+ cations. It means that this receptor can be considered as a potential extraction agent for nuclear waste treatment.