Abstract
Covalency is often considered to be an influential factor in driving An3+ vs. Ln3+ selectivity invoked by soft donor ligands. This is intensely debated, particularly the extent to which An3+/Ln3+ covalency differences prevail and manifest as the f-block is traversed, and the effects of periodic breaks beyond Pu. Herein, two Am complexes, [Am{N(E=PPh2)2}3] (1-Am, E=Se; 2-Am, E=O) are compared to isoradial [Nd{N(E=PPh2)2}3] (1-Nd, 2-Nd) complexes. Covalent contributions are assessed and compared to U/La and Pu/Ce analogues. Through ab initio calculations grounded in UV-vis-NIR spectroscopy and single-crystal X-ray structures, we observe differences in f orbital involvement between Am–Se and Nd–Se bonds, which are not present in O-donor congeners.
Original language | English |
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Pages (from-to) | 9459-9466 |
Number of pages | 8 |
Journal | Angewandte Chemie - International Edition |
Volume | 60 |
Issue number | 17 |
DOIs | |
State | Published - Apr 19 2021 |
Externally published | Yes |
Funding
We thank the U.S. Department of Energy, Office of Science, Basic Energy Sciences (DOE-BES), Heavy Element Chemistry Program at Los Alamos National Laboratory (LANL) (A.J.G., E.R.B., P.Y., B.L.S., S.A.K., F.D.W.; DE-AC52-06NA25396) for experimental Se donor work and theory, and the Center for Actinide Science and Technology (CAST), an Energy Frontier Research Center (EFRC) funded by DOE-BES for experimental O donor work (A.J.G., T.E.A.S.; DE-SC0016568). C.A.P.G. thanks a distinguished J. R. Oppenheimer Postdoctoral Fellowship (20180703PRD1) and L.M.S. the Exploratory Research program (20190091ER) both under LANL-LDRD (Laboratory Directed Research and Development). A.W.S. thanks a G.T. Seaborg Postdoctoral Fellowship at LANL. During manuscript preparation, we became aware of complementary solution spectroscopic studies on Am3+ with the LO ligand by Natrajan and Kaden (S. D. Woodall, Ph.D. Thesis, 2014, The University of Manchester), to be published separately.
Keywords
- actinides
- americium
- covalency
- spectroscopy
- structure