Spectroscopy of UO2Cl42− in basic aluminum chloride: 1-ethyl-3-methylimidazolium chloride

In this study we focus on the spectroscopic characterization of UO2Cl42− in 40:60 AlCl3:EMIC using multiple techniques. A combination of absorption, emission, excitation, two-photon excitation, Fourier transform Raman, and time-resolved emission spectra for solution (298 K) and frozen glass (75 K) samples have been measured and analyzed in terms of the electronic and vibrational structures of the UO2Cl42− ion. The spectroscopic properties of UO2Cl42− in single crystals are well known, and the analyses of the spectra of UO2Cl42− in 40:60 AlCl3:EMIC rely heavily on single crystal studies. Results are also compared with absorption spectra from a previous study of UO2Cl42− in 48:52 AlCl3:EMIC (a basic ionic liquid). The results from multiple spectroscopic measurements and their comparison with previous results help provide a picture of the structure and environment of UO2Cl42− in 40:60 AlCl3:EMIC.