Selective extraction of Pu(IV) by several substituted diamide ligands dissolved in a room temperature ionic liquid

The present paper deals with the selective extraction of Pu(IV) employing several novel diamide ligands dissolved in room temperature ionic liquids. The ligands containing iso-butyl, n-butyl, n-octyl and 2-ethylhexyl substituents to the diamides appended to a 2,4,6-tri-phenyl pyridine moiety were termed as L_I, L_II, L_III, and L_IV, respectively and were evaluated for the extraction of Pu(IV). The extraction of Pu(IV) follows the order L_III > L_II ≈ L_I > L_IV. The extraction of Am(III), Eu(III), Cs(I) and Sr(II) was negligible while marginally higher extraction of U(VI) was observed. Different parameters like extraction and stripping kinetics, metal - ligand stoichiometry were studied for all the ligands. (author)