Line broadening in high-resoln. NMR spectra caused by heteronuclear scalar coupling is described, and various adiabatic frequency-modulated decoupling schemes in high-resoln. NMR spectroscopy are compared. The CHRIP-95 decoupling scheme, which uses a linear frequency-swept pulse for adiabatic inversion of the magnetization, combined with an 80-step phase cycle that is derived from a 5-step phase cycle and a 16-step supercycle, allows on to cover very broad bandwidths with a great tolerance for variation in the RF amplitude. [on SciFinder (R)]