The quenching of excited uranyl ion by d6 metallocenes

Abstract

Quenching constants K_Q of uranyl luminescence by d⁶ metallocenes of Fe, Ru, and Os have been obtained both from luminescence intensity and lifetime measurements. The values of log₁₀K_Q are correlated with the oxidation potentials of metallocenes, in accordance with an elctron-transfer mechanism. This scheme is supported by photoreaction studies, where the formation of either the rather elusive [UO₂]⁺ ion or (in the case of osmocene solutions) uranium(IV) species has been observed: in the case of ferrocene solutions, ferricenium ion is also produced.