STRUCTURAL EFFECT OF N,N-DIALKYLAMIDE IN TOLUENE ON THE EXTRACTION OFURANIUM(VI)

N,N-dialkylamides having ethyl (DEDOA), butyl (DBDOA) and octyl (DODOA ) groups as the alkyl substituents were synthesized in order to invest igate their selectivity and capability in the extraction from acidic n itrate media in nuclear reprocessing. The extraction distribution coef ficients of U(VI) with the amides in toluene decrease in the order of DODOA > DBDOA > DEDOA. The structure of the extracted species was sugg ested from the dependence of the distribution ratio on the concentrati on of the extractant, with the aid of FT-IR spectra. The structural ef fect on the extraction capability of U(VI) was discussed in terms of t he molecular modelling. The effects of temperature on the distribution ratios were also considered, and the extraction reaction enthalpy was calculated.