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

Styers, William

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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

Language

eng

Handle URL

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

DOI

https://doi.org/10.15278/isms.2023.6921

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