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

作者：Iali Wissam; Olaru Alexandra M; Green Gary G R; Duckett Simon B

来源：Chemistry - A European Journal, 2017, 23(44): 10491-10495.

DOI：10.1002/chem.201702716

• hyperpolarization
• NMR spectroscopy
• parahydrogen
• SABRE

Signal amplification by reversible exchange (SABRE) is shown to allow access to strongly enhanced H-1 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 V 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 1H 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.

• 出版日期2017-8-4