title: A theoretical study of the inner-sphere disproportionation reaction mechanism of the pentavalent actinyl ions.
abstract: The inner-sphere mechanisms of the disproportionation reactions of U(V), Np(V), and Pu(V) ions have been studied using a quantum mechanical approach. The U(V) disproportionation proceeds via the formation of a dimer (a cation-cation complex) followed by two successive protonations at the axial oxygens of the donor uranyl ion. Bond lengths and spin multiplicities indicate that electron transfer occurs after the first protonation. A solvent water molecule then breaks the complex into solvated U(OH)2(2+) and UO2(2+) ions. Pu(V) behaves similarly, but Np(V) appears not to follow this path. The observations from quantum modeling are consistent with existing experimental data on actinyl(V) disproportionation reactions.
authors.affiliation: Nexia Solutions, Hinton House, Warrington, UK. helen.steele@nexiasolutions.com
authors.forename: Helen
authors.initials: H
authors.lastname: Steele
authors.forename: Robin J
authors.initials: RJ
authors.lastname: Taylor