University of Illinois Urbana-Champaign

ROTATIONAL AND INFRARED SPECTRA OF PYRIMIDINE: VIBRATIONAL GROUND STATE AND NINE VIBRATIONALLY EXCITED STATES

Styers, William

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6921.pdf
WE09_1.pptx

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https://hdl.handle.net/2142/122371

Description

Title
ROTATIONAL AND INFRARED SPECTRA OF PYRIMIDINE: VIBRATIONAL GROUND STATE AND NINE VIBRATIONALLY EXCITED STATES
Author(s)
Styers, William
Contributor(s)
  • McMahon, Robert J.
  • Woods, R. Claude
  • Zhao, Jianbao
  • Billinghurst, Brant E.
  • Amberger, Brent K.
  • Heim, Zachary N.
  • Esselman, Brian J.
Issue Date
2023-06-21
Keyword(s)
Rotational structure/frequencies
Abstract
Pyrimidine is an aromatic heterocycle in which meta C-H units of benzene are replaced by nitrogen atoms. Its detection in the ISM has been sought for decades as it is not only a building block of many biologically relevant molecules, but it could serve as a valuable tracer molecule for other aromatic and polycyclic aromatic compounds. In this work, we collected the millimeter-wave spectrum of pyrimidine from 130-750 GHz. This extended range greatly increases the range of rotational transitions we can observe in the ground and its nine lowest-energy vibrationally excited states. Over 10,000 transitions for the vibrational ground state have been least-squares fit to a A- and S-reduced sextic distorted-rotor Hamiltonians. To supplement the millimeter-wave spectrum, high-resolution infrared spectra were obtained from the Canadian Light Source and provide highly accurate and precise band origins for the vibrationally excited states. The three lowest energy fundamentals (ν₁₆, ν₁₁, and ν₂₄) have been fit to single-state Hamiltonians. The remaining vibrationally excited states presented in this work have perturbed frequencies due to Coriolis, Darling-Dennison, and Fermi coupling. The current progress toward a satisfactory treatment of these interactions will be presented.
Publisher
International Symposium on Molecular Spectroscopy
Type of Resource
Text
Genre of Resource
Conference Paper / Presentation
Language
eng
Handle URL
https://hdl.handle.net/2142/122371
DOI
https://doi.org/10.15278/isms.2023.6921

Owning Collections

Abstracts & Presentations - 2023 International Symposium on Molecular Spectroscopy PRIMARY