Accurate and Precise Measurement of heteronuclear Long-Range Couplings by a Gradient-Enhanced Two-Dimensional Multiple-Bond Correlation Experiment

摘要

We propose a phase-sensitive gradient-enhanced two-dimensional heteronuclear multiple-bond correlation (psge-2D HMBC) experiment for speedy, accurate, and precise measurement of ~2J_(CH) and ~3J_(CH). The experiment does not suppress one-bond correlations. Rather, the value of a desired long-range J_(CH) is obtained from the pertinent cross-peak pattern in the HMBC spectrum, using the corresponding ~1J_(CH) correlation pattern as reference. The application of the proposed experiment is illustrated for the trisaccharide raffinose.