University of Illinois Urbana-Champaign

Improvements To New Program For Spin-torsion-rotation & The Methyl-phenoxyl Radicals

Westerfield, J. H.

Content Files
TN04_1.pdf
6193.pdf

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https://hdl.handle.net/2142/116672

Description

Title
Improvements To New Program For Spin-torsion-rotation & The Methyl-phenoxyl Radicals
Author(s)
Westerfield, J. H.
Contributor(s)
  • Crabtree, Kyle N.
  • Zwier, Timothy S.
  • Welsh, Blair
Issue Date
2022-06-21
Keyword(s)
Radicals
Abstract
A new program, written in Julia, has been written to simulate and fit spectra of radicals with 3-fold internal rotors. The program now uses a single diagonalization stage implementation of the Rho Axis Method to provide more direct usage of the wavefunction symmetries for the $A$ states. The three different methyl positions provided test cases of potential spin-torsion coupling with varying internal barrier heights of about $V_{3} \approx 206$ \wn in ortho, $V_{3} \approx 64$ \wn in meta, and $V_{6} \approx 7$ \wn in para. Spectroscopic parameters determined from CCSD(T)/ANO0 calculations provided test cases for assigning states and simulating the spectra. The rotational spectra of ortho-, meta-, and para-methyl-phenoxyl radicals was collected through Chirped-Pulse Fourier Transform Microwave Spectroscopy. The radicals were produced from the appropriate methyl anisole precursors through pyrolysis in a SiC pyrolysis source attached to a pulsed valve. The temperature of the reactor was monitored with an infrared camera and the production of the radicals was monitored with 118 nm photoionization -Time of Flight Mass Spectrometry. Once the optimal temperature of the pyrolysis source was determined, the rotational spectrum was recorded from 7.5 -- 17.5 GHz. Each radical was fit as a closed-shell species using RAM36 and as an open-shell species using the new program which also included spin-torsion coupling terms.
Publisher
International Symposium on Molecular Spectroscopy
Type of Resource
text
Genre of Resource
Conference Paper / Presentation
Language
eng
Handle URL
https://hdl.handle.net/2142/116672
DOI
https://doi.org/10.15278/isms.2022.TN04
Copyright and License Information
Copyright 2022 held by the authors

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Abstracts & Presentations - 2022 International Symposium on Molecular Spectroscopy PRIMARY