F-19 Magic Angle Spinning Dynamic Nuclear Polarization Enhanced NMR Spectroscopy

The introduction of high-frequency, high-power microwave sources, tailored biradicals, and low-temperature magic angle spinning (MAS) probes has led to a rapid development of hyperpolarization strategies for solids and frozen solutions, leading to large gains in NMR sensitivity. Here, we introduce a protocol for efficient hyperpolarization of F-19 nuclei in MAS DNP enhanced NMR spectroscopy. We identified trifluoroethanol-d(3) as a versatile glassy matrix and show that 12mm AMUPol (with microcrystalline KBr) provides direct F-19 DNP enhancements of over 100 at 9.4T. We applied this protocol to obtain DNP-enhanced F-19 and F-19-C-13 cross-polarization (CP) spectra for an active pharmaceutical ingredient and a fluorinated mesostructured hybrid material, using incipient wetness impregnation, with enhancements of approximately 25 and 10 in the bulk solid, respectively. This strategy is a general and straightforward method for obtaining enhanced F-19 MAS spectra from fluorinated materials.


Published in:
Angewandte Chemie-International Edition, 58, 22, 7249-7253
Year:
May 27 2019
Publisher:
Weinheim, WILEY-V C H VERLAG GMBH
ISSN:
1433-7851
1521-3773
Keywords:
Laboratories:




 Record created 2019-08-01, last modified 2019-08-07


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