An adaptable NMR broadband decoupling scheme

A broadband heteronuclear decoupling scheme for high resolution liquid phase NMR spectroscopy is described, based on adiabatic fast passage with a linear frequency sweep. It is shown that the flexible choice of shaping function for the radiofrequency amplitude profile allows the method to be adapted to fit a wide range of sample parameters and experimental conditions. The practical limitations on phase cycling are emphasized. Expressions are derived to guide the choice of operating parameters so as to achieve a large effective bandwidth, low radiofrequency power dissipation, or weak cycling sidebands in the decoupled spectrum.