Achieving High Levels of NMR-Hyperpolarization in Aqueous Media With Minimal Catalyst Contamination Using SABRE.

Autor: Iali W; Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK., Olaru AM; Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK., Green GGR; York Neuroimaging Centre, The Biocentre, York Science Park Innovation Way, Heslington, York, YO10 5DD, UK., Duckett SB; Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK.
Jazyk: angličtina
Zdroj: Chemistry (Weinheim an der Bergstrasse, Germany) [Chemistry] 2017 Aug 04; Vol. 23 (44), pp. 10491-10495. Date of Electronic Publication: 2017 Jul 19.
DOI: 10.1002/chem.201702716
Abstrakt: Signal amplification by reversible exchange (SABRE) is shown to allow access to strongly enhanced 1 H NMR signals in a range of substrates in aqueous media. To achieve this outcome, phase-transfer catalysis is exploited, which leads to less than 1.5×10 -6  mol dm -3 of the iridium catalyst in the aqueous phase. These observations reflect a compelling route to produce a saline-based hyperpolarized bolus in just a few seconds for subsequent in vivo MRI monitoring. The new process has been called catalyst separated hyperpolarization through signal amplification by reversible exchange or CASH-SABRE. We illustrate this method for the substrates pyrazine, 5-methylpyrimidine, 4,6-d 2 -methyl nicotinate, 4,6-d 2 -nicotinamide and pyridazine achieving 1 H signal gains of approximately 790-, 340-, 3000-, 260- and 380-fold per proton at 9.4 T at the time point at which phase separation is complete.
(© 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.)
Databáze: MEDLINE
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