University of Illinois Urbana-Champaign

The z-1-cyano-1,3-butadiene (c5h5n) millimeter-wave rotational spectrum of the ground vibrational state and first two excited vibrational states (ν19 and ν27): a molecule of astrochemical importance

Dorman, P. Matisha

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4562.pdf

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https://hdl.handle.net/2142/107483

Description

Title
The z-1-cyano-1,3-butadiene (c5h5n) millimeter-wave rotational spectrum of the ground vibrational state and first two excited vibrational states (ν19 and ν27): a molecule of astrochemical importance
Author(s)
Dorman, P. Matisha
Contributor(s)
  • McMahon, Robert J.
  • Woods, R. Claude
  • McCarthy, Michael C.
  • Lee, Kelvin
  • Hyland, Grace E.
  • Kougias, Samuel M.
  • Esselman, Brian J.
Issue Date
2020-06-25
Keyword(s)
  • Perturbations
  • Resonances
  • *-Teller
Date of Ingest
2020-06-26T03:04:28Z
Abstract
We have synthesized and collected the 135 – 375 GHz rotational spectrum of Z-1-cyano-1,3-butadiene (\chem{C_5H_5N}), an open-chain isomer of pyridine. Its substantial dipole moments ($\mu_a$ = 3.3 D, $\mu_b$ = 2.3 D, B3LYP/6-311+G(2d,p)) make it an attractive species for detection by radioastronomy. We have fit the ground vibrational state to a low-error ($\sigma_{fit}$ = 0.039 MHz), partial octic, distorted-rotor Hamiltonian with 5,500+ distinct transitions in our frequency region, along with 34 hyperfine-resolved microwave transitions collected by the McCarthy Group in both a benzene/\chem{N_2} discharge and in a butadiene/\chem{CH_3CN} discharge. In collaboration, we were able to determine the nuclear hyperfine coupling constants and confirm the presence of Z-1-cyano-1,3-butadiene in the discharge experiments. This analysis provides the fundamental spectroscopic constants needed to support an astronomical search of Z-1-cyano-1,3-butadiene in the interstellar medium. Presently, we are analyzing the two lowest-energy fundamentals, \nub{19} and \nub{27} ($\Delta$E = 7.5 \wn, B3LYP/6-311+G(2d,p)). These fundamental states comprise a Coriolis-coupled dyad exhibiting $\it{a}-$ and $\it{b}$-type coupling, and this presentation will describe the progress of the dyad least-squares fit in the millimeter-wave analysis of Z-1-cyano-1,3-butadiene.
Publisher
International Symposium on Molecular Spectroscopy
Type of Resource
Text
Genre of Resource
Conference Paper / Presentation
Language
eng
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http://hdl.handle.net/2142/107483
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Copyright 2020 is held by the Author(s)

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Abstracts & Presentations - 2020 International Symposium on Molecular Spectroscopy PRIMARY