The Torsional Spectrum Of Doubly Deuterated Methanol Chd2oh

Coudert, L.H.

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https://hdl.handle.net/2142/50782 Copy

Description

Title

The Torsional Spectrum Of Doubly Deuterated Methanol Chd2oh

Author(s)

Coudert, L.H.

Contributor(s)

• Roy, P.
• Manceron, Laurent
• Margulès, L.
• Barros, J.
• Kwabia Tchana, F.
• Ndao, M.

Issue Date

2014-06-20

Keyword(s)

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

Abstract

Although the torsional spectrum of several isotopic species of methanol with a symmetrical \chem{CH_3} or \chem{CD_3} was analyzed some time ago, it is recently,\footnote{El Hilali, Coudert, Konov, and Klee, {\em J.\ Chem.\ Phys.}~{\bf 135} (2011) 194309} and only for the monodeuterated species \chem{CH_2DOH}, that such an analysis was extended to the case of an asymmetrical methyl group. In this talk, based on a Fourier transform high-resolution spectrum recorded in the 20 to 670~\wn\ region, the first analysis of the torsional spectrum of doubly deuterated methanol \chem{CHD_2OH} will be presented. The $Q$ branch of many torsional subbands could be observed and their assignment was initiated using a theoretical torsion-rotation spectrum computed with an approach accounting for the torsion-rotation Coriolis coupling and for the dependence of the generalized inertia tensor on the angle of internal rotation.\footnote{Lauvergnat, Coudert, Klee, and Smirnov, {\em J.\ Mol.\ Spectrosc.}~{\bf 256} (2009) 204} 46 torsional subbands were thus assigned. For 28 of them, their rotational structure could be assigned and fitted using an effective Hamiltonian expressed as a $J(J+1)$ expansion; and for 2 of them microwave transitions within the lower torsional level could also be included in the analysis.\footnote{Quade, Liu, Mukhopadhyay, and Su, {\em J.\ Mol.\ Spectrosc.}~{\bf 192} (1998) 378} In several cases these analysis revealed that the torsional levels are strongly perturbed.\footnote{Pearson, Yu, and Drouin, {\em J.\ Mol.\ Spectrosc.}~{\bf 280} (2012) 119} In the talk, the torsional parameters retrieved in the analysis of the torsional subband centers will be discussed. The results of the analysis of the rotational structure of the torsional subbands will be presented and we will also try to understand the nature of the perturbations. At last, preliminary results about the analysis of the microwave spectrum will be presented.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

English

Permalink

http://hdl.handle.net/2142/50782

DOI

https://doi.org/10.15278/isms.2014.FA06

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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