Neptunium photochemistry

Neptunium Valence Control Photochemistry and Heterogeneous Catalysis 461... 

The recent photochemistry interests at Oak Ridge have been turned to an examination of these aspects for neptunium in perchloric (15) and nitric acid (16) solutions. A perchloric acid medium provides a much simpler starting point because the CIO ion is not subject to photolysis as is the NO ion when exposed to light of 250-360 nm wavelength. Nevertheless, nitric acid media were ultimately examined because of their obvious practical importance. 

The solution photochemistry of the actinides begins with uranium none has been reported for actinium, thorium, and protactinium. Spectra have been obtained for most of the actinide ions through curium in solution (5). Most studies in actinide photochemistry have been done on uranyl compounds, largely to elucidate the nature of the excited electronic states of the uranyl ion and the details of the mechanisms of its photochemical reactions (5a). Some studies have also been done on the photochemistry of neptunium (6) and plutonium (7). Although not all of these studies are directed specifically toward separations, the chemistry they describe may be applicable. 

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