Temperature Quenching of Uranyl Ion Photoluminescence in Frozen Deuterated Aqueous Solutions of Sulfuric Acid

The effect of solvent deuteration revealed as a difference in the shape of temperature dependence curves for the lifetime of uranyl ion in the electronically excited state () upon warming H₂SO₄ solutions in ₂ and D₂SO₄ solutions in D₂O frozen at 77 K was detected. The value of in the case of D₂SO₄ was shown to be shorter in the glassy solution than in the polycrystalline sample, whereas the reverse was observed in frozen H₂SO₄ solutions. This effect was explained by dissimilar occurrence of phase transitions in H₂SO₄ and D₂SO₄ solutions, as well as by a decrease in the probability of nonradiative deactivation of *(UO²⁺₂) adsorbed on the surface of the crystal hydrate D₂SO₄·4D₂O as compared with that on the surface of the crystal hydrates H₂SO₄·4H₂O and H₂SO₄·6.5H₂O.