Ultrahigh resolution 19F and 31P NMR spectroscopy

Abstract NMR analyses of systems highly abundant in fluorine and phosphorus are becoming increasingly common in many areas, including pharmaceutical and environmental science. Often, such analyses can be challenging because overlap between multiplets degrades spectral resolution. Pure shift NMR methods overcome this problem by suppressing the effects of homonuclear scalar couplings in spectra. However, existing methods have insufficient bandwidth to cover the large chemical shift ranges commonly observed in fluorine and phosphorus NMR. Here, we report an ultra-broadband, ultrahigh resolution NMR experiment for measuring pure shift spectra of nuclei such as fluorine and phosphorus. Its usefulness is demonstrated in the analysis of complex systems highly abundant in these nuclei with far-reaching applications in pharmaceuticals, environmental sciences and synthetic chemistry. The method is simple to set up and does not require special NMR equipment.