Effect of Ionic Liquid on the Extraction of Lanthanides(III) from Nitric Acid Solutions with Phosphoryl-Containing Podands

The effect of the ionic liquid, 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide, on the extraction of lanthanides(III) from nitric acid solutions with phosphoryl-containing podands (2-(2-diphenylphosphoryl)-4-ethylphenoxy)methyl)diphenylphosphine oxide (1), (2-(2-diphenylphosphoryl)-4-ethylphenoxy)ethyl)diphenylphosphine oxide (2), and 2-[2-(diphenylphosphoryl)-4-ethylphenoxy]-N,N-dioctylacetamide (3) was studied. The stoichiometry of the extracted complexes was determined. The efficiency of extraction of lanthanides(III) with solutions of compounds 1-3 in dichloroethane from nitric acid solutions increases in the order 3 < 2 < 1. It has been established that, when replacing dichloroethane with an ionic liquid as a diluent, the extraction efficiency enhances. The magnitude of this effect decreases in the series of compounds 3 > 2 > 1. In the case of compound 1, the replacement of dichloroethane with an ionic liquid as a solvent is accompanied by a decrease in the extraction of lanthanides(III) at [HNO3] > 1.5 M.