$talk$ - Investigation of pure rotational spectroscopy of ethynylbenzonitrile isomers using chirped-pulse W-band spectroscopy

Abstract

Simple aromatic molecules may be precursors for polycyclic aromatic hydrocarbons in space, and some of the simplest ones are now detected in the earliest stages of star formation [1]. Evidence of benzonitrile (C6H5-CN) in the interstellar medium [2] questions the presence of related aromatic nitriles and their ring-chain derivatives. In light of previous work [3] on phenylpropiolonitrile (C6H5-C3N), we are investigating, by laboratory high-resolution studies, its ethynylbenzonitrile (HCC-C6H4-CN) derivatives where a -CN and a -CCH groups lie in ortho (2-ETB), meta (3-ETB) or para (4-ETB) positions.

The pure rotational spectrum of these compounds has been recorded at room temperature in the millimeter-wave domain using a chirped-pulse W-band (75–110 GHz) spectrometer. To facilitate spectral assignments, quantum chemical calculations have been performed using density functional theory at the $\omega$B97X-D/cc-pVQZ level of theory (geometry optimization, harmonic frequencies).

We will report a description of the experimental set-up and of our assignment procedure.

[1] A.Burkhardt et al., Nature Astronomy 5, 181-187 (2021)

[2] McGuire et al., Science 359, 202-205 (2018)

[3] Z.Buchanan et al., Journal of Molecular Spectroscopy 377, 111425 (2021)

Date
Jun 21, 2021 — Jun 25, 2021
Location
Virtual Conference
University of Illinois, USA
Jean-Thibaut Spaniol
Jean-Thibaut Spaniol
Master Student

Master 2 student with a passion for teaching that overpassed his love for spectroscopy.

Olivier Pirali
Olivier Pirali
Director of Research

My research interests includes high resolution molecular spectroscopy, laboratory astrophysics, and THz generation.

Marie-Aline Martin-Drumel
Marie-Aline Martin-Drumel
Researcher

My research interests focus on molecular spectroscopy of stable molecules and reactive species, and its applications for astrophysics and physical-chemistry.