University of Illinois Urbana-Champaign

Polycyclic Aromatic Hydrocarbon Growth In A Plasma Revealed By Ir-uv Action Spectroscopy

Lemmens, Alexander Karel

Content Files
WA05_1.pptx
5989.pdf

Permalink

https://hdl.handle.net/2142/116515

Description

Title
Polycyclic Aromatic Hydrocarbon Growth In A Plasma Revealed By Ir-uv Action Spectroscopy
Author(s)
Lemmens, Alexander Karel
Contributor(s)
  • Rijs, Anouk
  • Buma, Wybren Jan
  • Brünken, Sandra
  • Rap, Daniel
Issue Date
2022-06-22
Keyword(s)
Mini-symposium: Spectroscopy meets Chemical Dynamics
Abstract
\begin{wrapfigure}{l}{0pt} \includegraphics[scale=0.22]{Picture1.eps} \end{wrapfigure} The bottom-up formation of polycyclic aromatic hydrocarbons (PAHs) in combustion and interstellar gas-phase environments is still subject of extensive debate. As a result, accounting for PAH abundance in soot and the interstellar medium is far from trivial. Over the past years, a number of new reaction mechanisms have been proposed, spectroscopically identified and added as possible growth routes for larger PAHs.\footnote{Kaiser, R. I., Hansen, N. (2021), JPC A, 125(18), 3826-3840} These include reactions with radical phenyl rings and several small hydrocarbon radicals. We show here that a combination of these barrierless reactions is necessary to fully describe the chemistry leading to PAH growth. To this purpose we follow and characterize in our experiments the formation of PAHs in an electrical discharge. The fragments, products and reactive intermediates that are produced in this discharge are entrained in a molecular beam and structurally identified by mass selective IR-UV spectroscopy using an IR Free Electron Laser. Comparison of the mass-selected IR absorption spectra with IR spectra calculated for potential species associated with each of these spectra enables us to identify products including larger PAHs, radicals, and intermediates. The assigned structures serve as promising candidates for radio astronomical searches and highlight the necessity of describing PAH growth by an interconnected network of pathways.\footnote{Lemmens, A. K., Rap, D. B., Thunnissen, J. M., Willemsen, B., Rijs, A. M. (2020), Nat. Comm., 11(1), 1-7}
Publisher
International Symposium on Molecular Spectroscopy
Type of Resource
text
Genre of Resource
Conference Paper / Presentation
Language
eng
Handle URL
https://hdl.handle.net/2142/116515
DOI
https://doi.org/10.15278/isms.2022.WA05
Copyright and License Information
Copyright 2022 held by the authors

Owning Collections

Abstracts & Presentations - 2022 International Symposium on Molecular Spectroscopy PRIMARY