Investigation of actinide compounds by coupling X-ray absorption spectroscopy and quantum chemistry

X-ray absorption near edge structure (XANES) is a sensitive probe of the electronic structure, and can provide information about the valency, the unoccupied electronic states and the effective charge of the absorbing atom. In this work, XANES spectra are reported at the uranium L3, M5 thresholds and used to determined structural and electronic properties of actinide compounds. In addition, ligand K-edge spectra are analysed in order to better characterize the nature of the actinide-ligand bond. Experimental data analysis by simulating the absorption edge allows to compare the coordination polyhedrons, identify the electronic transitions and calculate the density of states associated with the absorption spectra. Moreover, a comparison between simulations of the experimental spectra and quantum chemical calculations is performed, in order to improve the model describing the final states and better understand the bonding properties of the cation with the ligand.