Phosphorganic N-heterocyclic ligands for selective binding of An(III): phosphinoxides, phosphine sulfides, and phosphonic esters

High-level waste (HLW) fractionation is one of the key tasks for complete closure of the nuclear fuel cycle. Extraction of target cations from HLW in individual form, in particular americium (III), is a complicated chemical and technological task, since HLW contain lanthanides (III) and curium (III) with extremely similar chemical properties. Finding new selective extractants for americium (III) isolation and understanding their mechanisms is an important fundamental task requiring the application of organic, inorganic chemistry and radiochemistry. The talk will reflect the main results on the study of new extraction systems based on four classes of organophosphorus N-heterocycles: phosphinoxides, phosphine sulfides, phosphonic esters and acids. On this set of compounds the dependence 'ligand structure - extraction properties with respect to An (IIII) and Ln (III)' will be shown when changing the extractant core, type of functional group and binding center. Based on the results obtained using modern physicochemical methods of analysis, the nature of the observed properties for the ligands that showed the best extraction characteristics will be discussed. (author)