title: Radiolytic yield of U(IV) oxidation into U(VI): a new mechanism for U(V) reactivity in acidic solution.
abstract: The yields of the radiolytic oxidation of U(IV) and of the U(VI) formation, measured by spectrophotometry, are found to be the same (G(-U(IV))(N2O) = G(U(VI))(N2O) = 8.4 x 10(-7) mol J(-1)) and almost double the H(2) formation yield (G(H(2)) = 4.4 x 10(-7) mol J(-1)) in the (60)Co gamma radiolysis of N(2)O-aqueous solutions in the presence of 2 mol L(-1) Cl(-) at pH = 0 (HCl). According to the mechanism of U(IV) radiolytic oxidation, we show that under the conditions of our experiments the U(V) ions do not disproportionate, but undergo a stoichiometric oxidation into U(VI) by H(+) with forming H(2).
authors.affiliation: Laboratoire de Chimie Physique/ELYSE, CNRS-Université Paris-Sud, Orsay, France.
authors.forename: E
authors.initials: E
authors.lastname: Atinault
authors.forename: V
authors.initials: V
authors.lastname: De Waele
authors.forename: J
authors.initials: J
authors.lastname: Belloni
authors.forename: C
authors.initials: C
authors.lastname: Le Naour
authors.forename: M
authors.initials: M
authors.lastname: Fattahi
authors.forename: M
authors.initials: M
authors.lastname: Mostafavi