Extraction Of Actinides And Lanthanides From Nitric Acid Solutions With Mixtures of 1,5-N,N′- Bis[(Diphenylphosphoryl)Acetyl(Hexyl)Amino]Pentane And New Asymmetrical Phosphonium- And Imidazolium Based Ionic Liquid

Abstract

A new dicationic ionic liquid 1-methyl-3-(4-(tributylphosphonio)butyl)-1H-imidazol-3-ium di[bis(trifluoromethanesulfonul)imide] [ImP][Tf2N]2, characterized by high hydrophobicity (solubility in water 9.2 × 10-4 mol/l) was synthesized. The extraction of U(VI), Th(IV), and lanthanides(III) from nitric acid solutions with mixtures of 1,5-N,N’-bis[(diphenylphosphoryl)acety(hexyl)amino]pentane (L), containing two bidentate fragments Ph2P(O)CH2C(O)N(Hex)- interconnected by pentamethylene spacer through amide nitrogen atoms, and [ImP][Tf2N]2 in 1,2-dichloroethane (DCE) was studied. During the extraction of metal ions in this system, a significant synergistic effect is observed. The influence of the composition of the aqueous and organic phases on the efficiency of the extraction of metal ions into the organic phase is considered, and the stoichiometry of the extracted complexes is determined. The synergistic effect at the extraction of Ln(III) from 3 M HNO3 solutions with a mixture of L and [ImP][Tf2N]2 in DCE is an order of magnitude higher than in the L–[C8mim][Tf2N]–DCE system.