A new two-dimensional NMR carbon−proton chemical shift correlation experiment, the MAS-J-HMQC experiment, is proposed for natural abundance rotating solids. The magnetization transfer used to obtain the correlations is based on scalar heteronuclear J couplings. The 2D map provides through-bond chemical shift correlations between directly bonded proton−carbon pairs in a way similar to that in corresponding high-resolution liquid-state experiments. The transfer through J coupling is shown to be efficient and more selective than those based on heteronuclear dipolar couplings. The experiment, which works at high MAS spinning frequencies, yields the unambiguous assignment of the proton resonances. The experiment is demonstrated on several organic compounds.

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Nuclear magnetic resonance (NMR) experiments are typically performed with samples immersed in a magnet shimmed to high homogeneity. However, there are many circumstances in which it is impractical or undesirable to insert objects or subjects into the bore of a high-field magnet. Here we present a methodology based on an adaptation of nutation echoes that provides resolved spectra in the presence of matched inhomogeneous static and radiofrequency fields, thereby opening the way to high-resolution ex situ NMR. The observation of chemical shifts is regained through the use of multiple-pulse sequences of correlated, composite z-rotation pulses, producing resolved NMR spectra of liquid samples.