Long-range proton-carbon coupling constants can be extracted from selective 1D inverse experiments

Selective 1D HMBC and Selective ge-1D HMBC experiments. 1D proton peaks show anti-phase pattern with respect to the active heteronuclear coupling.

Selective 1D HSQC-TOCSY, selective 1D HMQC-TOCSY , selective ge-1D HMQC-TOCSY and selective ge-1D HSQC-TOCSY experiments. 1D proton peaks show in-phase pattern with respect to the active heteronuclear coupling ( 94JMRA119-106 ).

A number of approaches have been also reported for accurate measurement by recording two separate 1D alpha/beta HMQC-TOCSY and 1D alpha/beta HSQC-TOCSY spectra, one from the alpha and one from beta 13C spin states. The relative displacement of these two signals affords directly the magnitude and the sign of the specific coupling.

Selective 1D pulse sequences based on heteronuclear cross polarization ( 96JMRA101-119 and 99MRC631 ). Values are extracted from in-phase multiplets.