Fourier transform spectra of the ν16, 2ν16, and 2ν16–ν16 bands of pyrrole taken with synchrotron radiationThis article is part of a Special Issue on Spectroscopy at the University of New Brunswick in honour of Colan Linton and Ron Lees.

TLDR: In this article, a rotationally-resolved vibrational spectra of three bands related to the lowest frequency vibration of the five-membered heterocycle pyrrole (C4H4NH) have been recorded using infrared light from the Canadian Light Source synchrotron as the source.

Abstract: Rotationally-resolved vibrational spectra of three bands related to the lowest frequency vibration of the five-membered heterocycle pyrrole (c-C4H4NH) have been recorded using infrared light from the Canadian Light Source synchrotron as the source. The N-H out-of-plane wagging fundamental band ν16 (474.6 cm–1) was recorded with 0.001 cm–1 resolution along with the first hot band 2ν16–ν16 (488.1 cm–1). Both are governed by c-type selection rules. The first overtone 2ν16 (962.7 cm–1) was recorded with 0.0013 cm–1 resolution and has a-type rotational structure. A total of 9103 lines were assigned and included in a simultaneous fit of all three bands. The band origins and excited state rotational parameters were well-determined using Watson’s S-reduced Hamiltonian, Ir representation as seen by the low rms error of the global fit: 0.000 172 cm–1.