Extraction of uranyl ion into ionic liquid by N,N,N ',N '-tetrabutylsuccinamide and spectroscopic study of uranyl complex

Interactions of uranyl with an amide ligand N,N,N',N'-tetrabutylsuccinamide (TBSA) in ionic liquid [Bmim][NTf2] was investigated. [UO2(TBSA)(3)](2+) is formed from uranyl and excess TBSA, with two TBSA ligands in bidentate mode and the third in monodentate mode. The efficiency of uranyl extraction by TBSA in [Bmim][NTf2] is dependent on the aqueous nitric acid concentrations. At low HNO3 concentration as 0.01 mol . L-1, the distribution ratio (D) is over 20 times larger than that in common organic solvents, and the extracted complex is [UO2(TBSA)(3)](2+). The D value decreases drastically with increase of HNO3 concentration.National Natural Science Foundation of China [91026011]SCI(E)ARTICLEtwchu@pku.edu.cn1161-16730