Time-resolved laser fluorescence spectroscopy of UO₂(CO₃)₃⁴⁻

Abstract

The objective of the present study is to examine the luminescence characteristics of UO2(CO3)3(4-) in detail using time-resolved laser fluorescence spectroscopy. The peak wavelengths and lifetime of UO2(CO3)3(4-) were determined at room temperature using the two excitation laser wavelengths of 266 and 448 nm. The peak wavelengths in the luminescence spectrum exhibited hypsochromic shifts compared with those of UO2(2+). The lifetime determined from several samples containing various uranium concentrations was 8.9 ± 0.8 ns. Explanations for the hindrance to the observation of the luminescence spectrum of UO2(CO3)3(4-) in previous investigations are discussed. The representative experimental parameters, which might interrupt the measurement of weak luminescence, are the insertion delay time of the detection device, the overlapped luminescence of the background materials and the primary inner filter effect in the sample solution.

Structural and spectroscopic studies of spontaneously formed crystalline Eu(iii)–aliphatic dicarboxylates at room temperature

“…An intensified CCD (ICCD) (iStar, Andor Technology) was used as the detector and its insertion delay time was managed relative to the incident laser pulse. 26 A long-path filter (500 nm cutoff) was placed in front of the detector to protect it from the scattered excitation light. The ICCD was set with a gate width of 5 ms and a gain of 1.…”

Influence of Alkaline Earth Metal Ions on Structures and Luminescent Properties of NamMnUO2(CO3)3(4–m–2n)– (M = Mg, Ca; m, n = 0–2): Time-Resolved Fluorescence Spectroscopy and Ab Initio Studies

“…4 Conversely, recent works have shown that the use of modern TRLFS set-up allows measuring UO2(CO3)3 4at ambient temperature. 21,24 It has been shown that the U(VI) luminescence is increasing when alkaline earth metal ions are added into a solution that contains UO2(CO3)3 4-, i.e., in the presence of dissolved bicarbonate. The repartition of these species (and solids) can be described in e.g.…”

“…The case of the carbonate species is particularly interesting. ,,,− Both anionic complexes UO 2 (CO 3 ) 2 2– and UO 2 (CO 3 ) 3 4– are characterized by an absorption spectrum shifted to longer wavelengths as compared with UO 2 2+ aqua ion and its hydrolyzed species. , Meinrath et al reported 20 years ago that the luminescence of UO 2 (CO 3 ) 2 2– seemed to be too weak to be easily observed . Conversely, recent works have shown that the use of modern TRLFS setup allows measuring UO 2 (CO 3 ) 3 4– at ambient temperature. , It has been shown that the U­(VI) luminescence is increasing when alkaline earth metal ions are added into a solution that contains UO 2 (CO 3 ) 3 4– , i.e. , in the presence of dissolved bicarbonate.…”

Determination of formation constants and specific ion interaction coefficients for CanUO2(CO3)3(4−2n)−complexes in NaCl solution by time-resolved laser-induced luminescence spectroscopy

“…[26][27][28] However, uranyl complexation by carbonate has been considered faintly detectable by TRLS for a long time, which was attributable to the weak luminescence of UO2-CO3 at room temperature as a result of the quenching effects of carbonates. 29 More recently, authors have been able to collect the luminescence emission spectra of uranyl carbonate complexes and measure their decay-time, 6,30 even in a pronounced quenching environment like seawater. 17 The achievable acquisition of binary species spectrum permitted determining quantitatively the stability constants of ternary species with steadily enhanced luminescence intensity upon the association with alkaline earth cations.…”