Synthesis and characterization of bisdiglycolamides for comparable extraction of Th4+, UO2 2+ and Eu3+ from nitric acid solution

The novel ligand N,N,N′′′′,N′′′′-tetrabutyl-N′′′,N′′′-(N″,N″-diethyl)-ethidene bisdiglycolamide (TBEE-BisDGA) and other eight analogous extractants have been synthesized and characterized by NMR and HRMS. The solvent extraction of Th4+, UO2 2+ and Eu3+ from nitric acid solution using the above BisDGA extractants was investigated in 1-dodecanol at 30 ± 1 °C. The extractants exhibited higher affinity toward Th4+ than UO2 2+ and Eu3+ in the present system. The maximum value of separation factor SF Th(IV)/U(VI) and SF Th(IV)/Eu(III) is 78.5 and 53.3 respectively for TBEE-BisDGA, 88.1 and 69.5 respectively in the case of TB i-PE-BisDGA at 3 M HNO3 solution.