N,N-dialkylamides having ethyl (DEDOA), butyl (DBDOA) and octyl (DODOA) groups as the alkyl substituents were synthesized
in order to investigate their selectivity and capability in the extraction from acidic nitrate media in nuclear reprocessing.
The extraction distribution coefficients of U(VI) with the amides in toluene decrease in the order of DODOA>DBDOA>DEDOA. The
structure of the extracted species was suggested from the dependence of the distribution ratio on the concentration of the
extractant, with the aid of FT-IR spectra. The structural effect on the extraction capability of U(VI) was discussed in terms
of the molecular modelling. The effects of temperature on the distribution ratios were also considered, and the extraction
reaction enthalpy was calculated.