The Microwave Spectrum Of Monodeuterated Acetamide Ch2dc(=o)nh2

Coudert, L.H.

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https://hdl.handle.net/2142/51222 Copy

Description

Title

The Microwave Spectrum Of Monodeuterated Acetamide Ch2dc(=o)nh2

Author(s)

Coudert, L.H.

Contributor(s)

• Guillemin, J.-C.
• Møllendal, H.
• Motiyenko, R.A.
• Margulès, L.
• Huet, T.R.
• Gutle, C.
• Konov, I.A.

Issue Date

2014-06-20

Keyword(s)

Mini-symposium: Astronomical Molecular Spectroscopy in the Age of ALMA

Abstract

Acetamide is an oblate asymmetric top displaying almost free internal rotation of its methyl group. The microwave spectrum of the normal species (\chem{CH_3C(=O)NH_2}) has already been studied and a value\footnote{Ilyushin, Alekseev, Dyubko, Kleiner, and Hougen, {\em J.\ Molec.\ Spectrosc.}~{\bf 227} (2004) 115} of only 25~\wn\ was retrieved for the height of the potential barrier hindering the internal rotation. No spectroscopic results are available about the monodeutared species with a partially deuterated \chem{CH_2D} methyl group which will be the subject of the present talk. The effects of deuteration on the hindering potential\footnote{Lauvergnat, Coudert, Klee, and Smirnov, {\em J.\ Molec.\ Spectrosc.}~{\bf 256} (2009) 204} will be investigated first. They lead to qualitative changes of the hindering potential no longer resembling that of the normal species and displaying several inequivalent minima.\footnote{Margul\`es, Coudert, M\o llendal, Guillemin, Huet and Jane\v{c}kov\`a, {\em J.\ Molec.\ Spectrosc.}~{\bf 254} (2009) 55} A determination of the torsional potential will be attempted through an analysis of the microwave spectrum of the monodeuterated species in which torsion-rotation energies are calculated with the approach developed for monodeuterated methanol,\footnote{Coudert, Zemouli, Motiyenko, Margul\`es, and Klee, {\em J.\ Chem.\ Phys.}~{\bf 140} (2014) 064307} accounting for the torsion-rotation Coriolis coupling and for the dependence of the inertia tensor on the torsional angle. A low temperature spectrum, recorded with the MB-FTMW spectrometer in Lille, has already been analyzed and 14 transitions could be assigned up to $J=6$. Room temperature spectra have also been recorded in the 7--91 and 150--165~GHz frequency ranges and more than 100 transitions have been assigned up to $J=16$ for the ground torsional state. In the paper, deuteration effects will be discussed and we hope to assign a sufficient number of microwave transitions in order to obtain the first quantitative information about the hindering potential of monodeuterated acetamide.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

English

Permalink

http://hdl.handle.net/2142/51222

DOI

https://doi.org/10.15278/isms.2014.FA07

Copyright and License Information

Copyright 2014 by the authors. Licensed under a Creative Commons Attribution 4.0 International License. http://creativecommons.org/licenses/by/4.0/

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