Investigations of the higher oxidation states of americium

INOR 541

Leigh R Martin, Leigh.Martin@inl.gov1, Bruce J. Mincher, bruce.mincher@inl.gov1, and Nicholas C. Schmitt, nicholas.schmitt@inl.gov2. (1) Aqueous Separations and Radiochemistry Department, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-2208, (2) Chemistry Department, Idaho National Laboratory, PO Box 1625, Idaho Falls, ID 83415-7113
Since the discovery of the transplutonium elements, the separation of trivalent actinides (An(III)) from the trivalent lanthanides (Ln(III)) has been of significant interest. Despite advances in this area neither soft donor extractants or size selective separations systems have reliably demonstrated the separation factors to required separate An(III) from Ln(III). However, the availability of higher oxidation states of Am may provide a pathway to achieve the separation of Am from Cm(III) and Ln(III) simultaneously using more conventional means. With reduction potentials of E°(III/IV) = +2.62V, E°(III/V) = +1.72V, E°(III/VI) = +1.68V in 1.0 M HClO4 oxidized Am species are powerful oxidants themselves. However, our investigations have shown that the stability of the oxidized species of Am may well be related to the method of preparation. Using different methods of oxidation may well lead to an oxidized Am species suitable for an effective separation from Am(III) and Ln(III).
 

Chemistry of Lanthanides and Actinides
2:00 PM-5:20 PM, Tuesday, August 21, 2007 BCEC -- 212, Oral

Division of Inorganic Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007