OPTIMIZED HETERONUCLEAR CROSS POLARIZATION IN LIQUIDS

It is demonstrated by theory, simulation, and experiment that it is possible to optimize heteronuclear cross-polarization experiments in liquids to such an extent that it becomes possible to transfer polarization uniformly through heteronuclear one-bond and long-range couplings. It is found that cross polarization is competitive with pulsed transfers, such as INEPT or DEPT, for the preparation of directly detected low-gamma nuclei. However for proton detection after two-way transfer, experiments employing heteronuclear multiple quantum coherence are usually more sensitive than cross-polarization experiments.