The characterization and understanding of the nature of chemical bonds in 4f- and 5f-
complexes are of both fundamental and industrial interest. For instance, lanthanide / actinide
chemical separation processes, used in the reprocessing of spent nuclear fuel, are largely based
on the concept of covalency. This separation is possible due to the larger radial extension of the
5f orbitals compared to the 4f ones, making them more available to interact with ligand orbitals.
From a theoretical point of view, covalent effects can be evaluated using perturbation molecular
orbital theory and electron density analysis techniques. However, such approaches may suffer
from the nature of the orbitals used in these analyses and can lead to surprising situations where
covalent bonds are obtained without any overlap. In this talk we will present another way to probe
the nature of the chemical bond in lanthanide and actinide complexes by using multi-reference
calculations to characterize different magnetic properties such as magnetic susceptibility,1 paramagnetic
NMR chemical shifts,2 magnetic circular dichroism (MCD)3 and circularly polarized
luminescence (CPL).
References
(1) Gendron, F.; Autschbach, J. J. Phys. Chem. Lett. 2017, 8, 673-678.
(2) Gendron, F.; Autschbach, J. J. Chem. Theory Comput. 2016, 12, 5309-5321.
(3) Gendron, F.; Fleischauer, V. E.; Duignan, T. J.; Scott, B. L.; Löble, M. W.; Cary, S. K.;
Kozimor, S.; Bolvin, H.; Neidig, M. L.; Autschbach, J. Phys. Chem. Chem. Phys. 2017, 19,
17300-17313.