A Fluorous Biphasic Solvent Extraction System for Lanthanides with a Fluorophilic β-Diketone Type Extractant

Abstract

The properties of a fluorous solvent extraction system for trivalent lanthanide metal ions are reported. A fluorinated extractant, 4,4,5,5,6,6,7,7,8,8,9,9,9-tridecafluoro-1-(2-thienyl)-1,3-nonanedione, and HFE-7200 (C₄F₉OC₂H₅) as the extraction solvent were chosen. With this fluorous extractant/solvent combination, higher extraction ratios and separation factors compared to a conventional organic solvent system (thenoyltrifluoroacetone in CHCl₃) were achieved for 5 heavy lanthanide ions (Lu, Yb, Tm, Er and Ho). On the other hand, light lanthanide ions (Nd, Pr, Ce and La) are hardly extracted, therefore enabling the mutual separation of light lanthanides from middle or heavy lanthanide ions.