Vibrational spectra of C2ν deuterium substituted pyridines. 3—pyridine‐3,5‐d2 and pyridine‐3,4,5‐d3

Abstract

AbstractPyridine‐3,5‐d2 and pyridine‐3,4,5‐d3 have been prepared. Isotopic constitution and label specificity of each of several preparations were verified by mass spectrometry and proton NMR. Liquid phase Raman and both liquid and vapor phase infrared spectra of these molecules are reported. Vibrational assignments consistent with frequency sum and product rule constraints are proposed. The relative rates of base‐catalyzed exchange of hydrogen with deuterium for the ring positions of pyridine‐N‐oxide were estimated during the course of the synthetic work. It is found that the 2 and 6 positions exchange very readily, that the 3 and 5 positions exchange slowly, and that the 4 position exchanges very slowly.