Harnessing polarisation transfer to indazole and imidazole through signal amplification by reversible exchange to improve their NMR detectability.
| Autor: | Fekete M; Centre for Hyperpolarization in Magnetic Resonance, Department of Chemistry, University of York, York, YO10 5NY, UK., Rayner PJ; Centre for Hyperpolarization in Magnetic Resonance, Department of Chemistry, University of York, York, YO10 5NY, UK., Green GGR; Centre for Hyperpolarization in Magnetic Resonance, Department of Chemistry, University of York, York, YO10 5NY, UK., Duckett SB; Centre for Hyperpolarization in Magnetic Resonance, Department of Chemistry, University of York, York, YO10 5NY, UK. |
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| Jazyk: | angličtina |
| Zdroj: | Magnetic resonance in chemistry : MRC [Magn Reson Chem] 2017 Oct; Vol. 55 (10), pp. 944-957. Date of Electronic Publication: 2017 Jun 20. |
| DOI: | 10.1002/mrc.4607 |
| Abstrakt: | The signal amplification by reversible exchange (SABRE) approach has been used to hyperpolarise the substrates indazole and imidazole in the presence of the co-ligand acetonitrile through the action of the precataysts [IrCl(COD)(IMes)] and [IrCl(COD)(SIMes)]. 2 H-labelled forms of these catalysts were also examined. Our comparison of the two precatalysts [IrCl(COD)(IMes)] and [IrCl(COD)(SIMes)], coupled with 2 H labelling of the N-heterocyclic carbene and associated relaxation and polarisation field variation studies, demonstrates the critical and collective role these parameters play in controlling the efficiency of signal amplification by reversible exchange. Ultimately, with imidazole, a 700-fold 1 H signal gain per proton is produced at 400 MHz, whilst for indazole, a 90-fold increase per proton is achieved. The co-ligand acetonitrile proved to optimally exhibit a 190-fold signal gain per proton in these measurements, with the associated studies revealing the importance the substrate plays in controlling this value. Copyright © 2017 The Authors. Magnetic Resonance in Chemistry published by John Wiley & Sons Ltd. (Copyright © 2017 The Authors. Magnetic Resonance in Chemistry published by John Wiley & Sons Ltd.) |
| Databáze: | MEDLINE |
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