Synergistic Effects of Tris(4-isopropyltropolonato)cobalt(III) on the Extraction of Lanthanum(III) and Lutetium(III) with Acetylacetone into Benzene

抄録

The synergistic effects of tris(4-isopropyltropolonato)cobalt(III) (Co(ipt)₃) on the extraction of lanthanum(III) and lutetium(III) with acetylacetone (Hacac) into benzene were investigated. A synergistic enhancement of the extraction of trivalent lanthanides was found in the presence of Co(ipt)₃. From equilibrium analysis, it was found that Ln(acac)₃ forms a 1:1 adduct, i.e., a binuclear complex, with the Co(ipt)₃ in benzene. The adduct formation constants (β_s,1) of Ln(acac)₃ with Co(ipt)₃ in benzene were determined, discussed, and compared with those reported previously. The β_s,1 values in the Ln(acac)₃ system became smaller than those in the Ln(tta)₃ system. The Lewis acidity of the Ln chelate had a significant effect on the adduct formation in the La(III) system and a relatively small effect in the Lu(III) system.