Synergic extraction of lanthanoids (III) with 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione in the presence of 1,10-phenanthroline or 2,9-dimethyl-1,10-phenanthroline

The synergic extraction of various tervalent lanthanoids (Ln(III)), La, Ce, Nd, Sm, Gd, Tb, Yb, and Lu, with 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione (Htta) in the presence of a bidentate heterocyclic amine, 1, 10-phenanthroline (phen) or 2,9-dimethyl-1,10-phenanthroline (dmp), in benzene was investigated. In the phen system, a synergic enhancement occurred by the formation of the adducts, Ln(tta)3phen; the higher adduct, Ln(tta)3(phen)2, was found for La and Ce. In the dmp system, the formation of only one adduct, Ln(tta)3dmp, was observed. The values of the adduct formation constants (βs,1) for phen increase with increasing atomic number of Ln(III); those for dmp, however, decrease with increasing atomic number of Ln(III) were lower than those for phen. (author)