Abstract
A series of structurally related novel derivatives of unsymmetrical diglycolamides (UDGA) were designed, synthesized, and applied to the extraction of uranium(VI), thorium(IV) and certain fission and activation products such as Zr(IV), Ba(II), Co(II), and Cs(I) from nitric acid solutions. The structure–reactivity relationship for the extraction of U(VI) and Th(IV) was studied. A symmetrical diglycolamide (DGA),
N
,
N
,
N
',
N
'-tetradodecyldiglycolamide (TD
2
DGA), was synthesized for comparison. The extraction of U(VI) and Th(IV) with
N
,
N
′-diisobutyl-
N
,
N
′-didodecyldiglycolamide (DiBD
2
DGA) from nitric acid medium was studied systematically. The distribution ratios of U(VI) and Th(IV) were determined in relation to the nitric acid concentration, salting-out agents, DiBD
2
DGA concentration, and temperature. The stoichiometry of the U(VI) and Th(IV) extractable species was determined to be UO
2
(NO
3
)
2
·2DiBD
2
DGA and Th(NO
3
)
4
·2DiBD
2
DGA, respectively, and the complexation was found to be exothermic. The FT-IR spectra of these extracted species were studied.