Removal of Residual Splitting in Nuclear Magnetic Double Resonance

Abstract

Double resonance experiments have been used as an aid in simplifying complex nuclear magnetic resonance spectra. However, in all except the simplest cases there is a residual splitting due to the coupling to the irradiated group even at relatively large irradiating fields. It is shown that this residual splitting can be greatly reduced or eliminated by a modulation of the frequency of the irradiating field. The conditions necessary to minimize the residual splitting are derived and discussed. The technique is illustrated with two examples.