19F 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 ¹⁹F nuclei in MAS DNP enhanced NMR spectroscopy. We identified trifluoroethanol‐d₃ as a versatile glassy matrix and show that 12 mm AMUPol (with microcrystalline KBr) provides direct ¹⁹F DNP enhancements of over 100 at 9.4 T. We applied this protocol to obtain DNP‐enhanced ¹⁹F and ¹⁹F–¹³C 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 ¹⁹F MAS spectra from fluorinated materials.