Convection compensation in 3D iDOSY-HMBC 1H-13C-correlation experiments

3D iDOSY-HMBC (3D incorporated Diffusion Ordered SpectroscopY-Heteronuclear Multiple Bond Correlation) pulse sequences were modified to incorporate convection compensation element. No additional delays were required, and convection compensation was directly constructed within the existing delay periods in 3D iDOSYHMBC pulse sequence. Convection compensation was achieved by pulsed field gradient double echo, thus avoiding the intensity loss normally related to stimulated echo methods. The incorporated convection compensation element improves the usability of 3D iDOSY-HMBC. In case of elevated temperatures, thermal convection leads to loss of resolution in DOSY-dimension or even to severe decrease of signal intensity, thus making convection uncompensated 3D iDOSY-HMBC infeasible. Aforementioned problems can be circumvented via utilization of the presented convection compensated 3D iDOSY-HMBC-versions.

Automated summary

In this study, 3D iDOSY-HMBC pulse sequences were modified to incorporate convection compensation element, which improved its usability. Convection compensation was achieved using the pulsed field gradient double echo method, avoiding intensity loss issues. This provides a new solution for the resolution decrease and signal intensity decrease problems at elevated temperatures.