title: High-Resolution Far-Infrared Spectroscopy of N-Substituted Two-Ring Polycyclic Aromatic Hydrocarbons: An Extended Study.
abstract: Polycyclic aromatic hydrocarbons (PAHs) and their N-substituted derivatives are among the largest species for which gas-phase high-resolution spectroscopy can be performed nowadays. In this paper we report the observation and analysis of spectra from several N-substituted two-ring PAHs, all taken in the "fingerprint" far-infrared region (<850 cm(-1)). Together with accurate measurements of their pure rotational transitions in the millimeter and submillimeter ranges, these synchrotron-based Fourier transform infrared (FTIR) measurements provide an accurate description of the rotational energy levels in the ground and low-energy excited vibrational states of these species. To complement the experimental data, anharmonic DFT calculations were performed to obtain relatively accurate rotational and vibrational parameters. The calculated results strongly support the rotational analysis and provide a good estimate of the equilibrium structures for each species. Extended measurements, analysis, and calculations are presented here for the far-IR bands of quinoline (C9H7N), isoquinoline (C9H7N), quinoxaline (C8H6N2), quinazoline (C8H6N2), [1,5]-naphthyridine (C8H6N2), [1,6]-naphthyridine (C8H6N2), and indole (C8H7N) molecules.
authors.affiliation: AILES beamline Synchrotron SOLEIL, L'Orme des Merisiers , 91190 Saint-Aubin, France.|Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS , Université Paris-Sud, Université Paris-Saclay, F-91405 Orsay, France.
authors.forename: S
authors.initials: S
authors.lastname: Gruet
authors.affiliation: AILES beamline Synchrotron SOLEIL, L'Orme des Merisiers , 91190 Saint-Aubin, France.|Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS , Université Paris-Sud, Université Paris-Saclay, F-91405 Orsay, France.
authors.forename: O
authors.initials: O
authors.lastname: Pirali
authors.affiliation: Université Lille, CNRS , UMR 8523 - PhLAM - Physique des Lasers Atomes et Molécules, F-59000 Lille, France.
authors.forename: M
authors.initials: M
authors.lastname: Goubet
authors.affiliation: Physics Department, University of New Brunswick , Fredericton E3B 5A3, Canada.
authors.forename: D W
authors.initials: DW
authors.lastname: Tokaryk
authors.affiliation: Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS , Université Paris-Sud, Université Paris-Saclay, F-91405 Orsay, France.
authors.forename: P
authors.initials: P
authors.lastname: Brechignac