Uranyl to uranium(IV) conversion through manipulation of axial and equatorial ligands

Bell, N. L. , Shaw, B., Arnold, P. L. and Love, J. B. (2018) Uranyl to uranium(IV) conversion through manipulation of axial and equatorial ligands. Journal of the American Chemical Society, 140(9), pp. 3378-3384. (doi: 10.1021/jacs.7b13474)

Abstract

The controlled manipulation of the axial oxo and equatorial halide ligands in the uranyl dipyrrin complex, UO2Cl(L), allows the uranyl reduction potential to be shifted by 1.53 V into the range accessible to naturally occurring reductants that are present during uranium remediation and storage processes. Abstraction of the equatorial halide ligand to form the uranyl cation causes a 780 mV positive shift in the UV/UIV reduction potential. Borane functionalization of the axial oxo groups causes the spontaneous homolysis of the equatorial U–Cl bond and a further 750 mV shift of this potential. The combined effect of chloride loss and borane coordination to the oxo groups allows reduction of UVI to UIV by H2 or other very mild reductants such as Cp*2Fe. The reduction with H2 is accompanied by a B–C bond cleavage process in the oxo-coordinated borane.

• Item Type: Articles
• Additional Information: The authors thank the University of Edinburgh and the EPSRC (Grant No. EP/M010554/1) for funding. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant Agreement No. 740311).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Bell, Dr Nicola
• Authors: Bell, N. L., Shaw, B., Arnold, P. L., and Love, J. B.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Journal of the American Chemical Society
• Publisher: American Chemical Society
• ISSN: 0002-7863
• ISSN (Online): 1520-5126
• Published Online: 18 February 2018
• Copyright Holders: Copyright © 2018 American Chemical Society
• First Published: First published in Journal of the American Chemical Society 140(9): 3378-3384
• Publisher Policy: Reproduced in accordance with the publisher copyright policy