Magnetic circular dichroism of UCl6− in the ligand-to-metal charge-transfer spectral regionElectronic supplementary information (ESI) available: Additional information and data regarding the experimental MCD and EPR spectra, the calculated energies of the LF states and 6d states, and plots of MCD calculations. CCDC 1544486. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7cp02572f

• Main Authors: Gendron, Frédéric, Fleischauer, Valerie E, Duignan, Thomas J, Scott, Brian L, Löble, Matthias W, Cary, Samantha K, Kozimor, Stosh A, Bolvin, Hélène, Neidig, Michael L, Autschbach, Jochen
• Format: Article
• Language: English
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/c7cp02572f

We present a combined ab initio theoretical and experimental study of the magnetic circular dichroism (MCD) spectrum of the octahedral UCl 6 − complex ion in the UV-Vis spectral region. The ground state is an orbitally non-degenerate doublet E 5/2u and the MCD is a -term spectrum caused by spin-orbit coupling. Calculations of the electronic spectrum at various levels of theory indicate that differential dynamic electron correlation has a strong influence on the energies of the dipole-allowed transitions and the envelope of the MCD spectrum. The experimentally observed bands are assigned to dipole-allowed ligand-to-metal charge transfer into the 5f shell, and 5f to 6d transitions. Charge transfer excitations into the U 6d shell appear at much higher energies. The MCD-allowed transitions can be assigned via their signs of the -terms: Under O h double group symmetry, E 5/2u → E 5/2g transitions have negative -terms whereas E 5/2u → F 3/2g transitions have positive -terms if the ground state g -factor is negative, as it is the case for UCl 6 − . We present a combined ab initio theoretical and experimental study of the magnetic circular dichroism (MCD) spectrum of the octahedral UCl 6 − complex ion in the UV-Vis spectral region.