Characterizing Pressure-Induced Uranium CH Agostic Bonds

DOI: 10.1002/anie.201411250
PMID: 25882329

Authors: Polly L. Arnold (The University of Edinburgh) , Alessandro Prescimone (The University of Edinburgh) , Joy H. Farnaby (Imperial College London) , Stephen M. Mansell (Heriot-Watt University) , Simon Parsons (The University of Edinburgh) , Nikolas Kaltsoyannis (University of Manchester)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Angewandte Chemie International Edition , VOL 54 , PAGES 6735 - 6739

State: Published (Approved)
Published: June 2015
Diamond Proposal Number(s): 9205

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[BOND]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.

Journal Keywords: Ensity Functional Calculations; High-Pressure Chemistry; Uranium; X-Ray Diffraction

Subject Areas: Chemistry


Instruments: I19-Small Molecule Single Crystal Diffraction

Added On: 12/01/2016 13:35

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