Barluzzi, L., Giblin, S. R., Mansikkamäki, A., & Layfield, R. A. (2022). Identification of oxidation state +1 in a molecular uranium complex. Journal of the American Chemical Society, 144(40), 18229–18233. https://doi.org/10.1021/jacs.2c06519
Identification of oxidation state +1 in a molecular uranium complex
|Author:||Barluzzi, Luciano1; Giblin, Sean R.2; Mansikkamäki, Akseli3;|
1Department of Chemistry, School of Life Sciences, University of Sussex, Brighton BN1 9JQ, U.K.
2School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA, U.K.
3NMR Research Group, University of Oulu, P.O. Box 8000, FI-90014 Oulu, Finland
|Online Access:||PDF Full Text (PDF, 3.1 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe2022102462783
American Chemical Society,
|Publish Date:|| 2022-10-24
The concept of oxidation state plays a fundamentally important role in defining the chemistry of the elements. In the f block of the periodic table, well-known oxidation states in compounds of the lanthanides include 0, +2, +3 and +4, and oxidation states for the actinides range from +7 to +2. Oxidation state +1 is conspicuous by its absence from the f-block elements. Here we show that the uranium(II) metallocene [U(η⁵-C₅ⁱPr₅)₂] and the uranium(III) metallocene [IU(η⁵-C₅ⁱPr₅)₂] can be reduced by potassium graphite in the presence of 2.2.2-cryptand to the uranium(I) metallocene [U(η⁵-C₅ⁱPr₅)₂]− (𝟏) (C₅ⁱPr₅ = pentaisopropylcyclopentadienyl) as the salt of [K(2.2.2-cryptand)]⁺. An X-ray crystallographic study revealed that 𝟏 has a bent metallocene structure, and theoretical studies and magnetic measurements confirmed that the electronic ground state of uranium(I) adopts a 5f³(7s/6dz²)¹(6dx²–y²/6dxy)¹ configuration. The metal–ligand bonding in 𝟏 consists of contributions from uranium 5f, 6d, and 7s orbitals, with the 6d orbitals engaging in weak but non-negligible covalent interactions. Identification of the oxidation state +1 for uranium expands the range of isolable oxidation states for the f-block elements and potentially signposts a synthetic route to this elusive species for other actinides and the lanthanides.
Journal of the American Chemical Society
|Pages:||18229 - 18233|
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
116 Chemical sciences
114 Physical sciences
The authors thank the EPSRC (Grants EP/V003089/1 and EP/V046659/1) and the Academy of Finland (Grant 332294) for funding, the U.K. National Crystallography Service for providing X-ray diffraction data on [K(2.2.2-crypt)] (EPSRC Grant EP/W02098X/1), Dr. R. Thorogate for providing access to a PPMS at the London Centre for Nanotechnology, Dr. A. Collauto at the Centre for Pulse EPR at Imperial College London for providing EPR data (EPSRC Grant EP/T031425/1), the University of Oulu (Kvantum Institute), and the CSC-IT Center for Science in Finland and the Finnish Grid and Cloud Infrastructure (persistent identifier urn:nbn:fi:research-infras-2016072533).
|Academy of Finland Grant Number:||
332294 (Academy of Finland Funding decision)
© 2022 The Authors. Published by American Chemical Society.