Use of Diethanolamine as a Viscous Solvent for Mixture Analysis by Multidimensional Heteronuclear ViscY NMR Experiments

ABSTRACT: Diethanolamine/DMSO-d6 as a viscous binary solvent is first reported for the individualization of low-polarity mixture components by multidimensional heteronuclear ViscY viscosity induces the slowing down of molecular tumbling, hence promoting magnetization transfer by dipolar longitudinal crossrelaxation. As a result, all 1H nuclei resonances within the same molecule may correlate in a 2D nuclear Overhauser effect spectroscopy (NOESY) spectrum, giving access to mixture analysis. We offer a new way to analyze mixtures by considering 3D heteronuclear heteronuclear single-quantum coherence-NOESY (HSQC-NOESY) experiments under viscous conditions. We state the individualization of four low-polarity chemical compounds dissolved in the diethanolamine/DMSO-d6 solvent blend using homonuclear selective 1D, 2D 1H-1H NOESY experiments and heteronuclear 1D, 2D 1H-19F heteronuclear Overhauser effect spectroscopy, 2D 1H-19F, 1H-31P HSQC-NOESY, and 3D 1H-19F-1H, 1H-31P-1H HSQC-NOESY experiments by taking profit from spin diffusion.

Automated summary

This study presents the use of diethanolamine/DMSO-d6 as a binary solvent for the individualization of low-polarity mixture components. The viscosity of the solvent induces molecular tumbling, which promotes magnetization transfer and allows for mixture analysis. Various experiments, including NOESY and HSQC-NOESY experiments, were performed to separate four low-polarity chemical compounds dissolved in the solvent blend.