University of Illinois Urbana-Champaign

The Study Of Direct D Atom Incorporation In Radicals At Low Temperature Probed By Chirped Pulse Mm-wave Spectroscopy

Dias, Nureshan

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5548.pdf
WC11_5548.pdf

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https://hdl.handle.net/2142/111334

Description

Title
The Study Of Direct D Atom Incorporation In Radicals At Low Temperature Probed By Chirped Pulse Mm-wave Spectroscopy
Author(s)
Dias, Nureshan
Contributor(s)
  • Suits, Arthur
  • Broderick, Bernadette M.
  • Gurusinghe, Ranil
Issue Date
2021-06-23
Keyword(s)
Dynamics and kinetics
Date of Ingest
  • 2021-09-24T21:09:32Z
  • 2022-01-21T16:09:07Z
Abstract
We are utilizing chirped pulse mm-wave spectroscopy in quasi-uniform supersonic flows at low temperature to probe isomer-specific product branching and kinetics. Earlier we have studied the photodissociation of the propargyl radical and monitored the branching between the three isomers of \chem{C_3H_2} and noted efficient conversion of \chem{H_2CCC} and HCCCH to the cyclic form induced by H addition/elimination, a process termed H-catalyzed isomerization. We will show that by adding a D atom source to the flow we observe very efficient D atom enrichment in the products through an analogous process of D addition/H elimination to \chem{C_3H_2} isomers occurring at 40K or below. Cyclic \chem{C_3HD} is the only deuterated isomer observed consistent with the expected addition/elimination yielding the lowest energy product. In the high-density region of the flow, we also observe singly deuterated propyne formed following stabilization of the D + \chem{C_3H_3} adduct, and both isotopomers \chem{CH_2DCCH} and \chem{CH_3CCD} are observed in nearly equal abundance. The implications of this for deuterium fractionation in astrochemical environments will be further discussed with the support of monodeuterated dark cloud model developed by Millar et al. Recent results for low temperature radical-radical reactions relevant to planetary atmospheres will also be highlighted.
Publisher
International Symposium on Molecular Spectroscopy
Type of Resource
Text
Genre of Resource
Conference Paper / Presentation
Language
eng
Permalink
http://hdl.handle.net/2142/111334
DOI
10.15278/isms.2021.WC11

Owning Collections

Abstracts & Presentations - 2021 International Symposium on Molecular Spectroscopy PRIMARY