Solvent extraction and separation of thorium(IV) and uranium(VI) by an ether-amide type tripodand

Summary 1,1,1-tris(N,N-diisobutylcarbamoyl-methyleneoxymethyl)propane (L) has been prepared and characterized by using IR, 1H NMR and positive-ion FAB mass spectra. The extraction of Th4+ and UO2 2+ with L was studied as a function of concentration of free extractant in an organic phase and of picrate in an aqueous phase from a picrate-nitrate medium at 293±1K. It was found that the extractability of L for Th4+ is larger than that for UO2 2+. Both extraction % of Th4+ and UO2 2+ decreased with an increase in the concentration of HNO3. The mechanism of extraction of Th4+ with L was proposed. The composition of extracted species of L with Th4+ in the organic phase is ThL(Pic)2(NO3)2. The results of extraction of trace 234Th4+ with L from the picrate-nitrate medium containing UO2 2+ (the initial concentration of UO2 2+, C 0 UO₂²⁺=1.23×10-4mol/dm3 (M)) agreed well with those from the extraction of single component solutions. The tripodand is useful in separation of Th4+ and UO2 2+ from each other in picrate-nitrate media with a relatively high separation factor.