Photochemical Reactions of Plutonium Ions in Perchloric Acid Solutions

Photochemical reactions of Pu(V), Pu(VI) in 0.01-1.00 M HClO₄ and of Pu(III), Pu(VI) in 9.4 M HClO₄ were studied. In the course of UV irradiation Pu(III) and Pu(V) are oxidized and Pu(VI) is reduced. With increasing acid concentration the oxidation rate increases, whereas the reduction rate decreases. The reaction mechanisms involving formation of excimers, i.e., dimers of plutonium ions occurring in the excited and ground states, are discussed.