New potentialities of the UNEX process using polyheterocyclic diamides

Abstract

The possibilities of using 2,2′-bipyridine-6,6′-dicarboxamides in modified versions of the UNEX process were examined. The stability constants of complexes of Eu(III), Am(III), Th(IV), U(VI), and Np(V) ions with certain diamides substituted in the amide moiety or pyridine ring in acetonitrile were determined. The logarithms of the stability constants exceeded 7 for Eu(III) and reached 9 for 5f elements. The ability of the selected diamides in nitrobenzene and trifluoromethyl phenyl sulfone (FS-13) diluents to extract Am(III), Th(IV), U(VI), and Eu(III) was studied.