Characterizing pressure-induced uranium C-H agostic bonds

Arnold, P. L., Prescimone, A., Farnaby, J. H. , Mansell, S. M., Parsons, S. and Kaltsoyannis, N. (2015) Characterizing pressure-induced uranium C-H agostic bonds. Angewandte Chemie (International Edition), 54(23), pp. 6735-6739. (doi: 10.1002/anie.201411250) (PMID:25882329) (PMCID:PMC4515102)

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 metalCH 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.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Farnaby, Dr Joy
• Authors: Arnold, P. L., Prescimone, A., Farnaby, J. H., Mansell, S. M., Parsons, S., and Kaltsoyannis, N.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Angewandte Chemie (International Edition)
• Publisher: Wiley
• ISSN: 1433-7851
• ISSN (Online): 1521-3773
• Published Online: 16 April 2015
• Copyright Holders: Copyright © 2015 The Authors
• First Published: First published in Angewandte Chemie (International Edition) 54(23): 6735-6739
• Publisher Policy: Reproduced under a Creative Commons License