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Tickner BJ, Dennington M, Collins BG, Gater CA, Tanner TFN, Whitwood AC, Rayner PJ, Watts DP, Duckett SB. Metal-Mediated Catalytic Polarization Transfer from para Hydrogen to 3,5-Dihalogenated Pyridines. ACS Catal 2024; 14:994-1004. [PMID: 38269038 PMCID: PMC10804365 DOI: 10.1021/acscatal.3c05378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 12/13/2023] [Accepted: 12/15/2023] [Indexed: 01/26/2024]
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 (pH2) 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.
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Affiliation(s)
- Ben. J. Tickner
- Centre
for Hyperpolarisation in Magnetic Resonance, University of York, Heslington YO10 5NY, U.K.
- Department
of Chemistry, University of York, Heslington YO10 5DD, U.K.
| | - Marcus Dennington
- Centre
for Hyperpolarisation in Magnetic Resonance, University of York, Heslington YO10 5NY, U.K.
- Department
of Chemistry, University of York, Heslington YO10 5DD, U.K.
| | - Benjamin G. Collins
- Centre
for Hyperpolarisation in Magnetic Resonance, University of York, Heslington YO10 5NY, U.K.
- Department
of Chemistry, University of York, Heslington YO10 5DD, U.K.
- Department
of Physics, Engineering and Technology, University of York, Heslington YO10 5DD, U.K.
| | - Callum A. Gater
- Centre
for Hyperpolarisation in Magnetic Resonance, University of York, Heslington YO10 5NY, U.K.
- Department
of Chemistry, University of York, Heslington YO10 5DD, U.K.
| | - Theo F. N. Tanner
- Department
of Chemistry, University of York, Heslington YO10 5DD, U.K.
| | | | - Peter J. Rayner
- Centre
for Hyperpolarisation in Magnetic Resonance, University of York, Heslington YO10 5NY, U.K.
- Department
of Chemistry, University of York, Heslington YO10 5DD, U.K.
| | - Daniel P. Watts
- Department
of Physics, Engineering and Technology, University of York, Heslington YO10 5DD, U.K.
| | - Simon B. Duckett
- Centre
for Hyperpolarisation in Magnetic Resonance, University of York, Heslington YO10 5NY, U.K.
- Department
of Chemistry, University of York, Heslington YO10 5DD, U.K.
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Ullah MS, Mankinen O, Zhivonitko VV, Telkki VV. Ultrafast transverse relaxation exchange NMR spectroscopy. Phys Chem Chem Phys 2022; 24:22109-22114. [PMID: 36074123 PMCID: PMC9491048 DOI: 10.1039/d2cp02944h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Molecular exchange between different physical or chemical environments occurs due to either diffusion or chemical transformation. Nuclear magnetic resonance (NMR) spectroscopy provides a means of understanding the molecular exchange in a noninvasive way and without tracers. Here, we introduce a novel two dimensional, single-scan ultrafast Laplace NMR (UF LNMR) method to monitor molecular exchange using transverse relaxation as a contrast. The UF T2–T2 relaxation exchange spectroscopy (REXSY) method shortens the experiment time by one to two orders of magnitude compared to its conventional counterpart. Contrary to the conventional EXSY, the exchanging sites are distinguished based on T2 relaxation times instead of chemical shifts, making the method especially useful for systems including physical exchange of molecules. Therefore, the UF REXSY method offers an efficient means for quantification of exchange processes in various fields such as cellular metabolism and ion transport in electrolytes. As a proof of principle, we studied a halogen-free orthoborate based ionic liquid system and followed molecular exchange between molecular aggregates and free molecules. The results are in good agreement with the conventional exchange studies. Due to the single-scan nature, the method potentially significantly facilitates the use of modern hyperpolarization techniques to boost the sensitivity by several orders of magnitude. An ultrafast two-dimensional NMR method allows quantification of molecular exchange rates efficiently based on T2 relaxation contrast.![]()
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Affiliation(s)
- Md Sharif Ullah
- NMR Research Unit, Faculty of Science, University of Oulu, P.O.Box 3000, 90014 Oulu, Finland.
| | - Otto Mankinen
- NMR Research Unit, Faculty of Science, University of Oulu, P.O.Box 3000, 90014 Oulu, Finland.
| | - Vladimir V Zhivonitko
- NMR Research Unit, Faculty of Science, University of Oulu, P.O.Box 3000, 90014 Oulu, Finland.
| | - Ville-Veikko Telkki
- NMR Research Unit, Faculty of Science, University of Oulu, P.O.Box 3000, 90014 Oulu, Finland.
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Tickner BJ, Komulainen S, Palosaari S, Heikkinen J, Lehenkari P, Zhivonitko VV, Telkki VV. Hyperpolarised NMR to aid molecular profiling of electronic cigarette aerosols. RSC Adv 2022; 12:1479-1485. [PMID: 35425197 PMCID: PMC8979170 DOI: 10.1039/d1ra07376a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 12/15/2021] [Indexed: 11/21/2022] Open
Abstract
Signal amplification by reversible exchange (SABRE) hyperpolarisation is used to enhance the NMR signals of nicotine and acrolein in methanol-d4 solutions of electronic cigarette aerosols. Consequently, detection of 74 μM nicotine is possible in just a single scan 1H NMR spectrum. The first example of an aldehyde hyperpolarised using SABRE is demonstrated and we work towards novel real-world applications of SABRE-hyperpolarised NMR for chemical analysis.
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Affiliation(s)
- Ben J Tickner
- NMR Research Unit, Faculty of Science, University of Oulu 90014 Finland
| | - Sanna Komulainen
- NMR Research Unit, Faculty of Science, University of Oulu 90014 Finland
| | - Sanna Palosaari
- Cancer and Translational Medicine Research Unit, Faculty of Medicine, University of Oulu 90014 Finland
- Medical Research Center Oulu, Faculty of Medicine, University of Oulu and Oulu University Hospital 90014 Finland
| | - Janne Heikkinen
- Cancer and Translational Medicine Research Unit, Faculty of Medicine, University of Oulu 90014 Finland
| | - Petri Lehenkari
- Cancer and Translational Medicine Research Unit, Faculty of Medicine, University of Oulu 90014 Finland
- Medical Research Center Oulu, Faculty of Medicine, University of Oulu and Oulu University Hospital 90014 Finland
- Division of Orthopedic Surgery, Oulu University Hospital 90220 Finland
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