Selectivity of extraction of trivalent transplutonium elements with neutral organophosphorus compounds from halogenide solutions

Selectivity of extraction of americium, curium, californium, and einsteinium with some neutral organophosphorus compounds (tri-n-heptylphosphate, diisooctylmethylphosphonate, dibutyldecylphosphosphinate, triisohyptylphospineoxide) from chloride and bromide solutions. Extraction has been conducted with a mixture of 241Am, 244Cm, 252Cf, and 254Es taken in trace amounts. The separation factors have been determined directly from spectra of α radiation of aqueous and organic phases. Experimental and calculated separation factors in these systems have been compared. The calculation points out that a higher extrability of californium and einsteinium as compared with that of americium and curium is attained with a rise in the number of halogenide ions entering the inner coordination sphere of the actinoide atom in the complex being extracted at a simultaneous decrease of a complexing degree in an aqueous phase. The difference in extraction selectivity of chlorides and bromides of f-elements is due to a decrease of inner-sphere complexing when passing from chloride complexes to bromides