TY - JOUR
T1 - Covalent bond shortening and distortion induced by pressurization of thorium, uranium, and neptunium tetrakis aryloxides
AU - Shephard, Jacob J.
AU - Berryman, Victoria E. J.
AU - Ochiai, Tatsumi
AU - Walter, Olaf
AU - Price, Amy N.
AU - Warren, Mark R.
AU - Arnold, Polly L.
AU - Kaltsoyannis, Nikolas
AU - Parsons, Simon
N1 - Funding Information:
We thank the University of Edinburgh and the EPSRC for funding through EP/H004823/1 and EP/M010554/1, EP/J018139/1. This project has also received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 740311). We thank Diamond Light Source and STFC for provision of synchrotron beam-time (MT16139), and the University of Manchester’s Computational Shared Facility for access to computing resources and associated support services. We thank the Japan Society for the Promotion of Science for International Fellowship funding to T.O. Additional discussion, analysis, and writing of this manuscript (PLA and ANP) was supported by the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division at the Lawrence Berkeley National Laboratory under Contract DE-AC02-05CH11231. Some of the experimental data used in this research were generated through access to the ActUsLab/FMR under the Framework of access to the Joint Research Centre Physical Research Infrastructures of the European Commission (Proposal AUL-2017-20-208, Pressure-induced covalency in neptunium organometallic molecules, Research Infrastructure Access Agreement No. 2018-05). We are grateful to Dr Roberto Caciuffo of the same organisation for insightful discussions on the manuscript.
Funding Information:
We thank the University of Edinburgh and the EPSRC for funding through EP/H004823/1 and EP/M010554/1, EP/J018139/1. This project has also received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 740311). We thank Diamond Light Source and STFC for provision of synchrotron beam-time (MT16139), and the University of Manchester’s Computational Shared Facility for access to computing resources and associated support services. We thank the Japan Society for the Promotion of Science for International Fellowship funding to T.O. Additional discussion, analysis, and writing of this manuscript (PLA and ANP) was supported by the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division at the Lawrence Berkeley National Laboratory under Contract DE-AC02-05CH11231. Some of the experimental data used in this research were generated through access to the ActUsLab/FMR under the Framework of access to the Joint Research Centre Physical Research Infrastructures of the European Commission (Proposal AUL-2017-20-208, Pressure-induced covalency in neptunium organometallic molecules, Research Infrastructure Access Agreement No. 2018-05). We are grateful to Dr Roberto Caciuffo of the same organisation for insightful discussions on the manuscript.
Publisher Copyright:
© 2022, The Author(s).
PY - 2022/10/7
Y1 - 2022/10/7
N2 - Covalency involving the 5f orbitals is regularly invoked to explain the reactivity, structure and spectroscopic properties of the actinides, but the ionic versus covalent nature of metal-ligand bonding in actinide complexes remains controversial. The tetrakis 2,6-di-tert-butylphenoxide complexes of Th, U and Np form an isostructural series of crystal structures containing approximately tetrahedral MO4 cores. We show that up to 3 GPa the Th and U crystal structures show negative linear compressibility as the OMO angles distort. At 3 GPa the angles snap back to their original values, reverting to a tetrahedral geometry with an abrupt shortening of the M-O distances by up to 0.1 Å. The Np complex shows similar but smaller effects, transforming above 2.4 GPa. Electronic structure calculations associate the M-O bond shortening with a change in covalency resulting from increased contributions to the M-O bonding by the metal 6d and 5f orbitals, the combination promoting MO4 flexibility at little cost in energy.
AB - Covalency involving the 5f orbitals is regularly invoked to explain the reactivity, structure and spectroscopic properties of the actinides, but the ionic versus covalent nature of metal-ligand bonding in actinide complexes remains controversial. The tetrakis 2,6-di-tert-butylphenoxide complexes of Th, U and Np form an isostructural series of crystal structures containing approximately tetrahedral MO4 cores. We show that up to 3 GPa the Th and U crystal structures show negative linear compressibility as the OMO angles distort. At 3 GPa the angles snap back to their original values, reverting to a tetrahedral geometry with an abrupt shortening of the M-O distances by up to 0.1 Å. The Np complex shows similar but smaller effects, transforming above 2.4 GPa. Electronic structure calculations associate the M-O bond shortening with a change in covalency resulting from increased contributions to the M-O bonding by the metal 6d and 5f orbitals, the combination promoting MO4 flexibility at little cost in energy.
U2 - 10.1038/s41467-022-33459-7
DO - 10.1038/s41467-022-33459-7
M3 - Article
SN - 2041-1723
VL - 13
JO - Nature Communications
JF - Nature Communications
IS - 1
ER -