AN ADAPTABLE NMR BROAD-BAND 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 expe rimental conditions. The practical limitations on phase cycling are em phasized, Expressions are derived to guide the choice of operating par ameters so as to achieve a large effective bandwidth, low radiofrequen cy power dissipation, or weak cycling sidebands in the decoupled spect rum.