THE COMPLETE ROTATIONAL SPECTRUM OF CH3NCO UP TO 376 GHz

Kisiel, Zbigniew

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https://hdl.handle.net/2142/79156 Copy

Description

Title

THE COMPLETE ROTATIONAL SPECTRUM OF CH3NCO UP TO 376 GHz

Author(s)

Kisiel, Zbigniew

Contributor(s)

• De Lucia, Frank C.
• Winnewisser, Manfred
• Fortman, Sarah
• Medvedev, Ivan
• Alonso, José L.
• Kolesniková, Lucie

Issue Date

23-Jun-15

Keyword(s)

Large amplitude motions, internal rotation

Abstract

The methylisocyanate molecule, CH$_3$NCO, is of interest as a potential astrophysical species and as a model system for the study of quasisymmetric behavior. The rotational spectrum is made very complex by the presence in CH$_3$NCO of two large-amplitude motions: an almost free internal rotation and a low barrier skeletal bending motion. This challenging spectrum has, nevertheless, been assigned at 8-38 GHz by Stark spectroscopyfootnote{J.Koput, {it J.~Mol.~Spectrosc.} {bf 115}, 131 (1986).} and has been measured at 117-376 GHz with the broadband FASSST technique.footnote{Z.Kisiel et al., 65$^{th}$ OSU Symposium on Molecular Spectroscopy, The Ohio State University, Ohio 2010, RC-13.} vspace{0.2cm} We presently report the results of measuring this spectrum also in supersonic expansion for the transitions below 40 GHz, and at room-temperature in the region between 40 and 120 GHz. In this way we are finally able to confirm the assignment of the ground state and of the internal rotation $m$=1 state and to analyse the nitrogen hyperfine splitting structure. It is also possible to confidently transfer the Stark-based assignment to the transition sequences measured in the mm-wave region, and to assign high $K_a$ sequences. Various models for fitting this spectrum are explored but, even without more extensive fits, we are now able to present temperature scalable linelists for astrophysical applications.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

English

Permalink

http://hdl.handle.net/2142/79156

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