Halse, Meghan E. orcid.org/0000-0002-3605-5551, Procacci, Barbara orcid.org/0000-0001-7044-0560, Henshaw, Sarah Louise et al. (2 more authors) (2017) Coherent evolution of parahydrogen induced polarisation using laser pump, NMR probe spectroscopy : Theoretical framework and experimental observation. Journal of Magnetic Resonance. pp. 25-38. ISSN 1090-7807
Abstract
We recently reported a pump-probe method that uses a single laser pulse to introduce parahydrogen (p-H2) into a metal dihydride complex and then follows the time-evolution of the p-H2-derived nuclear spin states by NMR. We present here a theoretical framework to describe the oscillatory behaviour of the resultant hyperpolarised NMR signals using a product operator formalism. We consider the cases where the p-H2-derived protons form part of an AX, AXY, AXYZ or AA′XX′ spin system in the product molecule. We use this framework to predict the patterns for 2D pump-probe NMR spectra, where the indirect dimension represents the evolution during the pump-probe delay and the positions of the cross-peaks depend on the difference in chemical shift of the p-H2-derived protons and the difference in their couplings to other nuclei. The evolution of the NMR signals of the p-H2-derived protons, as well as the transfer of hyperpolarisation to other NMR-active nuclei in the product, is described. The theoretical framework is tested experimentally for a set of ruthenium dihydride complexes representing the different spin systems. Theoretical predictions and experimental results agree to within experimental error for all features of the hyperpolarised 1H and 31P pump-probe NMR spectra. Thus we establish the laser pump, NMR probe approach as a robust way to directly observe and quantitatively analyse the coherent evolution of p-H2-derived spin order over micro-to-millisecond timescales.
Metadata
Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2017 The Authors. | ||||
Keywords: | Hyperpolarisation, Long-lived states, Parahydrogen-induced polarisation, Photochemistry, Spin dynamics | ||||
Dates: |
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Institution: | The University of York | ||||
Academic Units: | The University of York > Faculty of Sciences (York) > Chemistry (York) | ||||
Funding Information: |
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Depositing User: | Pure (York) | ||||
Date Deposited: | 04 Apr 2017 14:20 | ||||
Last Modified: | 04 Feb 2024 00:47 | ||||
Published Version: | https://doi.org/10.1016/j.jmr.2017.03.005 | ||||
Status: | Published | ||||
Refereed: | Yes | ||||
Identification Number: | https://doi.org/10.1016/j.jmr.2017.03.005 | ||||
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