High Resolved <sup>2</sup>H NMR Spectroscopy at Deuterium Natural Abundance Level
The spin-lattice relaxation times T <sub>1</sub> for deuterium nuclei in several deuterated compounds (methanol-d <sub>4</sub>, ethanol-d <sub>6</sub>, benzene-d <sub>1</sub>, dimethylsulfoxide-d <sub>6</sub>) were measured at higher temperatures (in the range 300-375 K). In all cases almost linear increase of times T <sub>1 </sub>with temperature was observed revealing increase of molecular mobility and decrease of the correlation times. One may expect relaxation times of order 2-3 s for deuteriums in small organic molecules at temperatures above 350 K. Thus for the standard magnetic field inhomogeneity of order 0.5 Hz in NMR <sup>1</sup>H one can obtain linewidths of order 0.1-0.2 Hz in <sup>2</sup>H NMR spectra. Such “high resolved” <sup>2</sup>H NMR spectra give the information about chemical shifts and coupling constants J(H-D) (or J(H-H)= ( <sub>H</sub>/ <sub>D</sub>) J(H-D)) including those between magnetically equivalent protons unobservable in <sup>1</sup>H NMR spectra. New or more exact data on coupling constants were obtained for ethanol, propanol, 1,2-dichloroethane and 1,4-dioxane.