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

Diethanolamine/DMSO- d 6 as a viscous binary solvent is first reported for the individualization of low-polarity mixture components by multidimensional heteronuclear ViscY NMR experiments under spin diffusion conditions. Solvent viscosity induces the slowing down of molecular tumbling, hence promoting magnetization transfer by dipolar longitudinal cross-relaxation. As a result, all 1 H 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- d 6 solvent blend using homonuclear selective 1D, 2D 1 H- 1 H NOESY experiments and heteronuclear 1D, 2D 1 H- 19 F heteronuclear Overhauser effect spectroscopy, 2D 1 H- 19 F, 1 H- 31 P HSQC-NOESY, and 3D 1 H- 19 F- 1 H, 1 H- 31 P- 1 H HSQC-NOESY experiments by taking profit from spin diffusion.