Millimeter-wave spectrum of 2-cyanopyridine in its ground state and the dyad of its lowest energy vibrationally excited states, ν30 and ν21

Dorman, P. Matisha

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https://hdl.handle.net/2142/104235 Copy

Description

Title

Millimeter-wave spectrum of 2-cyanopyridine in its ground state and the dyad of its lowest energy vibrationally excited states, ν30 and ν21

Author(s)

Dorman, P. Matisha

Contributor(s)

• McMahon, Robert J.
• Woods, R. Claude
• Esselman, Brian J.

Issue Date

2019-06-20

Keyword(s)

Rotational structure/frequencies

Abstract

"In this study, we collected the 135-375 GHz rotational spectrum of 2-cyanopyridine, a N-heteroatom analog of the interstellar molecule, benzonitrile. 2-Cyanopyridine's strong dipole moment ($\mu_a = 5.5$ D, $\mu_b = 1.9$ D) and the fact that it is a cyano substituted aromatic molecule make it another attractive species for detection by radioastronomy. The ground state of 2-cyanopyridine was fit to a centrifugally distorted single state model using Kisiel’s ASFIT ($N_{lines} \sim 6500$, $\sigma = 0.043$) and primarily includes $^bR_{-1, 1}, ^aR_{0, 1},$ and $^bR_{1, 1}$ type lines. The two lowest fundamentals, $\nu_{30}$ and $\nu_{21}$, display effects of strong Coriolis interactions and require treatment \textit{via} a two-state model. Discreet local resonances with $\Delta K_a = 3$ perturbation have been seen along with the effects of a strong a-type global perturbation. Currently, using Pickett's SPFIT, around 16,000 distinct rotational transitions for these states have been measured, from $K_a = 0$ to 49 and J"" = 11 to 146, leading to an experimental energy difference of $\Delta E_{30,21}=793379.9$ MHz ($\sim 26.5 \hspace{0.5mm} cm^{-1}$, compared to a $30.6 \hspace{0.5mm} cm^{-1}$ B3LYP/6-311+G(2d,p) anharmonic frequency prediction). Six perturbation terms, including $G_a, G_b, F_{bc}$ and the higher order terms, $G_a^J, G_b^J, G_b^K$, are currently being treated; and those predicted agree to within 10\% of the prediction. This presentation will expand on the progress of the two state least squares fit and full results of the millimeter-wave analysis of 2-cyanopyridine."

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Permalink

http://hdl.handle.net/2142/104235

DOI

https://doi.org/10.15278/isms.2019.RI08

Copyright and License Information

Copyright 2019 P. Matisha Dorman

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