Characterizing Pressure‐Induced Uranium CH Agostic Bonds |
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| Authors: | Prof Polly L Arnold Dr Alessandro Prescimone Dr Joy H Farnaby Dr Stephen M Mansell Prof Simon Parsons Prof Nikolas Kaltsoyannis |
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| Institution: | 1. EaStCHEM School of Chemistry, University of Edinburgh, The King's Buildings, Edinburgh, EH9 3FJ (UK);2. Current address: Department of Chemistry, University of Basel, Spitalstrasse 51, 4056 Basel (Switzerland);3. Current address: Department of Chemistry, Imperial College London, South Kensington Campus, London, SW7 2AZ (UK);4. Current address: Institute of Chemical Sciences, Heriot‐Watt University, Edinburgh, EH14 4AS (UK);5. Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ (UK) |
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| Abstract: | The diuranium(III) compound UN′′2]2(μ‐η6:η6‐C6H6) (N′′=N(SiMe3)2) has been studied using variable, high‐pressure single‐crystal X‐ray crystallography, and density functional theory . In this compound, the low‐coordinate metal cations are coupled through π‐ and δ‐symmetric arene overlap and show close metal? CH contacts with the flexible methyl CH groups of the sterically encumbered amido ligands. The metal–metal separation decreases with increasing pressure, but the most significant structural changes are to the close contacts between ligand CH bonds and the U centers. Although the interatomic distances are suggestive of agostic‐type interactions between the U and ligand peripheral CH groups, QTAIM (quantum theory of atoms‐in‐molecules) computational analysis suggests that there is no such interaction at ambient pressure. However, QTAIM and NBO analyses indicate that the interaction becomes agostic at 3.2 GPa. |
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| Keywords: | actinides density functional calculations high‐pressure chemistry uranium X‐ray diffraction |
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