Extraction of europium and americium into phenyltrifluoromethyl sulfone by using hydrogen dicarbollylcobaltate in the presence of N,N′-diethyl-N,N′-diphenyl-2,6-dipicolinamide

Extraction of microamounts of europium and americium by a phenyltrifluoromethyl sulfone (FS 13) solution of hydrogen dicarbollylcobaltate (H + B − ) in the presence of N , N ′-diethyl- N , N ′-diphenyl-2,6-dipicolinamide (EtPhDPA, L) has been investigated. The equilibrium data have been explained assuming that the species HL + , HL 2 + , ML 2 3+ , ML 3 3+ and ML 4 3+ (M 3+ = Eu 3+ , Am 3+ ) are extracted into the organic phase. The values of extraction and stability constants of the cationic complexes in FS 13 saturated with water have been determined. It was found that the stability constants of the corresponding complexes EuL n 3+ and AmL n 3+ , where n = 2, 3, 4 and L is EtPhDPA, in water-saturated FS 13 are comparable.