Lighting up spin systems: enhancing characteristic 1H signal patterns of fluorinated molecules

Abstract

Fluorine is becoming increasingly prevalent in medicinal chemistry, both in drug molecules and in molecular probes. The presence of fluorine allows convenient monitoring of such molecules in complex environments by NMR spectroscopy. However, sensitivity is a persistent limitation of NMR, especially when molecules are present at low concentrations. Here, sensitivity issues with ¹H NMR are mitigated by sharing ¹⁹F photochemically-induced dynamic nuclear polarisation with ¹H nuclei. Unlike direct ¹H enhancement, this method enhances ¹H signals without significantly distorting multiplet intensities, and has the potential to enable the use of suitable molecules as low-concentration probes.