The Vibrational Spectra of Pyridine and Pyridine-<i>d</i>5

Abstract

Pyridine-d5 has been prepared by exchange between pyridine vapor and heavy water in the presence of a palladium catalyst. Infrared and Raman spectra are reported for pyridine and pyridine-d5 over the spectral range 300–4000 cm−1. Interpretation of the spectra with the help of the product rule and by analogy with the fundamental frequencies of benzene and benzene-d6 leads to complete sets of frequencies for the 27 vibrational degrees of freedom of pyridine and of pyridine-d5. The frequency assignment for pyridine does not differ greatly from previous ones, but is believed to be more reliable because of the additional spectroscopic data.