H-Detected Heteronuclear Multiple-Quantum Coherence HMQC Spectra

1 H-Detected Heteronuclear Multiple-Quantum Coherence (HMQC) Spectra 

The HMQC experiment is about 16 or 100 times more sensitive for C and N detections, respectively, than the conventional heteronuclear shift-correlated experiment. The sensitivity advantt e in this experiment (as well as in the HMBC experiment described later) is due to the fact that it relies on the equilibrium magnetizations derived from protons. Since this magnetization is proportional to the latter population difference in proton energy levels (rather than the smaller population difference of C enei levels), a stronger NMR signal is obtained. Moreover, since the strength of the NMR signal 

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