Homonuclear decoupling for liquid-state NMR.

We present a solution to the problem of decoupling of a homonuclear two-spin system having weak isotropic scalar coupling. We describe non-selective pulse sequences that create an effective field perpendicular to the coupling interaction over a broad range of chemical shifts, with a magnitude proportional to the chemical shifts. Effective decoupling is achieved when the difference in chemical shifts imprinted on the perpendicular field is sufficiently larger than the coupling between the spins. The proposed methods scale down the chemical shifts. The pulse sequences may be useful in various applications in nuclear magnetic resonance spectroscopy.