Highly Efficient Solvent Extraction of Americium and Europium by Using Hydrogen Dicarbollylcobaltate and N,N′-Diethyl-N,N′-bis(4-ethylphenyl)-1,10-phenanthroline-2,9-dicarboxamide

Solvent extraction of microamounts of Eu 3+ and Am 3+ from water into nitrobenzene by means of a mixture of hydrogen dicarbollylcobaltate (H + B − ) and N,N′ -diethyl- N,N′ -bis(4-ethylphenyl)-1,10-phenanthroline-2,9-dicarboxamide (L) was studied. The equilibrium data were explained assuming that the species HL + , HL 2 + , ML 2 3 + , and ML 3 3 + (M 3+ = Eu 3+ , Am 3+ ; L = N,N′ -diethyl- N,N′ -bis(4-ethylphenyl)-1,10-phenanthroline-2,9-dicarboxamide) are extracted into the organic phase. Extraction and stability constants of the cationic complex species in nitrobenzene saturated with water were determined and are discussed. The reached separation factors SF Am/Eu in this two-phase system are in the range of 19–99. From the experimental results it is apparent that this very effective N,N′ -diethyl- N,N′ -bis(4-ethylphenyl)-1,10-phenanthroline-2,9-dicarboxamide receptor for the Eu 3+ and Am 3+ cations could be considered as a potential extraction agent for nuclear waste treatment. Graphical Abstract