Absorption spectrum and reaction kinetics of the photoreactive state of the uranyl ion

Abstract

µs and ns excitation of aqueous solution of uranyl salts produces a short-lived absorption (t_½ca. 1·05 µs) which is systematically quenched on addition of a variety of organic substrates known to photoreduce UO²⁺₂ ion; the isotope effect of 2·76 obtained with CH₃OH and CD₃OH exactly matches that found for quenching of the fluorescence of UO²⁺₂ by these substrates, and absolute rate constants have been determined for some photoreactions of UO²⁺₂ for the first time.