Tickner, Ben J, Dennington, Marcus, Collins, Benjamin G et al. (6 more authors) (2024) Metal-mediated catalytic polarisation transfer from parahydrogen to 3,5-dihalogenated pyridines. ACS Catalysis. pp. 994-1004. ISSN 2155-5435
Abstract
The neutral catalysts [IrCl(H) 2(NHC)(substrate) 2] or [IrCl(H) 2(NHC)(substrate)(sulfoxide)] are used to transfer polarization from para hydrogen ( pH 2) to 3,5-dichloropyridine and 3,5-dibromopyridine substrates. This is achieved in a rapid, reversible, and low-cost process that relies on ligand exchange within the active catalyst. Notably, the sulfoxide-containing catalyst systems produced NMR signal enhancements between 1 and 2 orders of magnitude larger than its unmodified counterpart. Consequently, this signal amplification by reversible exchange hyperpolarization method can boost the 1H, 13C, and 15N nuclear magnetic resonance (NMR) signal intensities by factors up to 4350, 1550, and 46,600, respectively (14.0, 1.3, and 15.4% polarization). In this paper, NMR and X-ray crystallography are used to map the evolution of catalytically important species and provide mechanistic rational for catalytic efficiency. Furthermore, applications in spontaneous radiofrequency amplification by stimulated emission and NMR reaction monitoring are also shown.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2024 The Authors. Published by American Chemical Society. |
Dates: |
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Institution: | The University of York |
Academic Units: | The University of York > Faculty of Sciences (York) > Chemistry (York) The University of York > Faculty of Sciences (York) > Physics (York) |
Funding Information: | Funder Grant number EUROPEAN COMMISSION 101053248 |
Depositing User: | Pure (York) |
Date Deposited: | 20 Dec 2023 10:40 |
Last Modified: | 13 Feb 2025 05:30 |
Published Version: | https://doi.org/10.1021/acscatal.3c05378 |
Status: | Published |
Refereed: | Yes |
Identification Number: | 10.1021/acscatal.3c05378 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:206853 |
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Description: Metal-MediatedCatalyticPolarizationTransferfromparaHydrogento3,5-DihalogenatedPyridines
Licence: CC-BY 2.5