Understanding the unique paradigm in the extraction of tri- and tetravalent actinide/lanthanide ions by a diglycolamide-functionalized dendrimer in RTIL medium

A dendrimer of tris(2-aminoethyl)amine (TREN), containing six diglycolamide (DGA) pendent arms (TREN-G1-DGA), was evaluated for the extraction of different actinides and Eu³⁺ ions in a methylimidazolium-based room temperature ionic liquid (RTIL; C₄mim.NTf₂). The results indicated a significant enhancement of the extraction of the trivalent metal ions Am³⁺ and Eu³⁺ in the RTIL medium as compared to that in molecular diluents, whereas in the case of the tetravalent actinides Pu⁴⁺ and Np⁴⁺ the extraction was least affected by the diluent media. This is explained based on a different extraction mechanism for the trivalent and the tetravalent metal ions. The extraction behaviour was well corroborated with the help of a luminescence study. (authors)