Uranyl solutions, absorption spectra

At room temperature, the electronically excited uranyl ion has an unusually long lifetime with respect to that of excited states of organic molecules. The excited state absorption spectrum (e.s.a.) of UO2 in aqueous solution has been observed at X niax 590 nm using laser flash... 

The majority of the photochemical studies with actinide ions have been carried out with the uranyl (UC ion. This ion is yellow in color both in the solid and solution states. The early photochemistry of this ion has been reviewed. " Excitation of this ion results in an LMCT absorption that involves a transition from an essentially nonbonding 7r-orbital on oxygen into an empty 5/orbital on uranium. This LMCT assignment is that given to the weak visible bands in the absorption spectrum at 500 nm and 360 nm. The absorption spectrum also shows a series of bands of increasing intensity to higher energy. The positions of the absorption bands of are very sensitive to both temperature and the chemical environment... 

The negative character of the complex has been demonstrated by electrolytic transference experiments. Its ccanposltlon has been deduced by the isolation of solid compounds from solutions of the type described abovo and by the similarity of the absorption spectrum of such solutions with that of crystalline cesium uranyl nitrate, CsUOg(NOg)g ... 

Figure 9.1. Spectra of uranyl nitrate. A The corrected emission spectrum of 10 M uranyl nitrate in 0.1 N ff2

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