Hunting the relatives of benzonitrile: Rotational spectroscopy of dicyanobenzenes

Abstract

The recent interstellar detections of -CN containing aromatic species, namely benzonitrile, 1-cyanonaphthalene, and 2-cyanonaphthalene, bring renewed interest in related molecules that could participate in similar reaction networks. To enable new interstellar searches for benzonitrile derivatives, the pure rotational spectra of several related species need to be investigated in the laboratory. We have recorded the pure rotational spectra of ortho- and meta-dicyanobenzene in the centimetre and millimetre-wave domains. Assignments were supported by high-level quantum chemical calculations. Using Markov chain Monte Carlo simulations, we also searched for evidence of these molecules towards TMC-1 using the GOTHAM survey. Accurate spectroscopic parameters are derived from the analysis of the experimental spectra, allowing for reliable predictions at temperatures of interest (i.e. 10–300 K) for astronomical searches. Our searches in TMC-1 for both ortho- and meta- isomers provide upper limits for the abundances of the species.

Publication
Astronomy and Astrophysics
Olivia Chitarra
Olivia Chitarra
PhD student

PhD student at Institut des Sciences Moléculaires d’Orsay (ISMO) under the direction of Olivier Pirali and Marie-Aline Martin-Drumel.

Zachary Buchanan
Zachary Buchanan
Chateaubriand Fellow

Zachary was a Chateaubriand Fellow at ISMO in 2019.

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.