Influence of Alkaline Earth Metal Ions on Structures and Luminescent Properties of Na_mM_nUO₂(CO₃)₃^{(4–m–2n)–} (M = Mg, Ca; m, n = 0–2): Time-Resolved Fluorescence Spectroscopy and Ab Initio Studies

Abstract

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Influence of the First Coordination of Uranyl on Its Luminescence Properties: A Study of Uranyl Binitrate with N,N-Dialkyl Amide DEHiBA and Water

“…26 The shifts between the ground and excited state stretching frequencies ∆ν s are 65 and 49 cm −1 for the UO 2 (NO 3 ) 2 and UO 2 (NO 3 ) 2 (DEHiBA) 2 , respectively, while the theoretical shifts equal to 90 cm −1 in average. As it has been explained in previous works, 24,25 our theoretical methodology tends to overestimate the vibrational frequencies values; thus we can consider that the agreement between theoretical and experimental data is satisfactory. Moreover, it is difficult to estimate the degree of anharmonicity effects in experimental spectra, which might obviously decrease the band spacings in the higher energy region.…”

“…The choice of the used QM methods is justified in previous works. 24,25,29 The ground and excited-state molecular geometries were optimized with Gaussian 16 30 software including scalar relativistic effects and using the PBE0 functional of the density. 31 For the UO…”

Influence of the first coordination of uranyl on its luminescence properties: study of uranyl binitrate with N,N-dialkyl amide DEHiBA and water

“…26 The shifts between the ground and excited state stretching frequencies ∆ν s are 65 and 49 cm −1 for the UO 2 (NO 3 ) 2 and UO 2 (NO 3 ) 2 (DEHiBA) 2 , respectively, while the theoretical shifts equal to 90 cm −1 in average. As it has been explained in previous works, 24,25 our theoretical methodology tends to overestimate the vibrational frequencies values; thus we can consider that the agreement between theoretical and experimental data is satisfactory. Moreover, it is difficult to estimate the degree of anharmonicity effects in experimental spectra, which might obviously decrease the band spacings in the higher energy region.…”

Effect of temperature on the complexation of triscarbonatouranyl(vi) with calcium and magnesium in NaCl aqueous solution

“…The concentration of U(VI) varied from 50 to 250 μmol kgw -1 in order to increase the luminescence at the highest temperatures. Indeed, the emission spectra contain features originating from vibronic transitions from the lowest excited state to the ground state manifold, 11→00 of the hot band and 10→0ν (ν = 0, 1, 2, 3) of other peaks [53]. With the increase in temperature, the less-defined bands of UO2(CO3)3 4-were continuously red-shifted.…”