Infrared Predissociation Spectroscopy Of Protonated Methyl Cyanide

Marimuthu, Aravindh Nivas

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https://hdl.handle.net/2142/116732 Copy

Description

Title

Infrared Predissociation Spectroscopy Of Protonated Methyl Cyanide

Author(s)

Marimuthu, Aravindh Nivas

Contributor(s)

• Brünken, Sandra
• Redlich, Britta
• Thorwirth, Sven
• Huis in’t Veld , Frank

Issue Date

2022-06-22

Keyword(s)

Mini-symposium: Benchmarking in Spectroscopy

Abstract

\begin{wrapfigure}[19]{r}{2.5in} \vspace{-25pt} \includegraphics[scale=0.4]{CH3CNH+_figure.eps} \end{wrapfigure} Methyl cyanide (CH$_3$CN) was among the first polyatomic molecules detected by radio-astronomical observations of the interstellar medium (ISM)[1]. As methyl cyanide has a proton affinity much larger than that of H$_2$, its protonated version (CH$_3$CNH$^+$) is postulated to form efficiently via exothermic proton transfer from H$_3^+$ to CH$_3$CN in the interstellar medium. In this talk, we present a comprehensive experimental and quantum-chemical study of the gas phase vibrational spectrum of CH$_3$CNH$^+$ [2]. We employed the widely tuneable free electron lasers for infrared experiments (FELIX) coupled to a cryogenic ion trap instrument [3] for our measurements. The spectrum was recorded in the 300-1700 and 2000-3300 cm$^{-1}$ spectral regions using infrared predissociation (IRPD) action spectroscopy with neon as a weakly bound messenger atom. The assignment of the vibrational modes is based on anharmonic frequency calculations performed at the CCSD(T)/ANO2 level of theory. We demonstrate that the comparatively low-cost ANO0 basis-set provides accurate estimates on the influence of the weakly-bound neon atom as a tag in the IRPD experiments. The data presented here will support astronomical searches for the CH$_3$CNH$^+$ ion in space. \\\rule{5cm}{0.1mm}\\ \scriptsize{[1] P.M. Solomon, K.B. Jefferts, A.A. Penzias and R.W. Wilson, Astrophys. J. 168 (1971) L107}\\ \scriptsize{[2] A. N. Marimuthu, F. Huis in’t Veld, S. Thorwirth, B. Redlich and S. Br\"{u}nken, J. Mol. Spec. 379 (2021) 111477}\\ \scriptsize{[3] P. Jusko, S. Br\"{u}nken, O. Asvany, S. Thorwirth, A. Stoffels, L. van der Meer, G. Berden, B. Redlich, J. Oomens and S. Schlemmer, Faraday Discuss. 217, (2019), 172}

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Handle URL

https://hdl.handle.net/2142/116732

DOI

https://doi.org/10.15278/isms.2022.WB08

Copyright and License Information

Copyright 2022 held by the authors

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