Synergic extraction of lanthanide(III) ions with 2-thenoyltrifluoroacetone in the presence of 2,2′-bipyridine or pyridine

Abstract

The synergic extraction of various tervalent lanthanides (Ln), La, Ce, Nd, Sm, Gd, Tb, Yb and Lu, with 2-thenoyltrifluoroacetone (Htta) in the presence of a bidentate heterocyclic amine, 2,2′-bipyridine (bipy), in benzene was investigated. The synergic enhancement was attributed to the formation of the adducts, Ln(tta)3(bipy). The synergic extraction of La(III), Sm(III) and Lu(III) with Htta and a unidentate amine, pyridine (py), was also studied and the formation of the adducts, Ln(tta)3py and Ln(tta)3(py)2, was observed. The adduct formation constants, βs,1 and βs,2, were determined. The βs,2 values for py decrease with increasing atomic number of Ln(III), but βs,1 values for bipy increase with increasing atomic number of Ln(III). The synergic extraction constants and the separation factors in the bipy system were also determined.