DETERMINATION OF HYDRATION NUMBER OF URANYL ION BY ~1HNMR

The hydration number of uranyl ion is determined by 1HNMR at low temperature. In perchloric acid, the hydration number of uranyl ion varies from 4 to 5 with the increment of CH2O/CUO22+ mole ratio. In hydrochloric acid, the hydration number of uranyl ion decreases with the increment of CHCl/Cuo22+ mole ratio. When CHCl/CUO22+ =4. 0,uranyl ion is coordinated with no water molecule. In nitric acid,when CHNO3/CUO 22+≥2. 0 uranyl ion is coordinated with two water molecules and it is independent of the concentration of nitric acid. The probable structures of coordination compounds of U(VI) in solution are discussed.