Radical Intermediates In The Addition Of Oh To Propene: Photolytic Precursors And Angular Momentum Effects

Brynteson, Matthew D.

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https://hdl.handle.net/2142/50780 Copy

Description

Title

Radical Intermediates In The Addition Of Oh To Propene: Photolytic Precursors And Angular Momentum Effects

Author(s)

Brynteson, Matthew D.

Contributor(s)

• Butler, Laurie
• Lin, Jim J.
• Lee, Shih-H
• Booth, Ryan S.
• Womack, Carrie C.

Issue Date

2014-06-18

Keyword(s)

Mini-symposium: Spectroscopy in Kinetics and Dynamics

Abstract

We investigate the photolytic production of two radical intermediates in the reaction of OH with propene, one from addition of the hydroxyl radical to the terminal carbon and the other from addition to the center carbon. In a collision-free environment, we photodissociate a mixture of 1-bromo-2-propanol and 2-bromo-1-propanol at 193 nm to produce these radical intermediates. Using a velocity map imaging apparatus, we measured the speed distribution of the recoiling bromine atoms, yielding the distribution of kinetic energies of the nascent C$_{3}$H$_{6}$OH radicals + Br. Resolving the velocity distributions of Br($^{2}$P$_{1/2}$) and Br($^{2}$P$_{3/2}$) separately with 2+1 REMPI allows us to determine the total (vibrational + rotational) internal energy distribution in the nascent radicals. Using an impulsive model to estimate the rotational energy imparted to the nascent C$_{3}$H$_{6}$OH radicals, we predict the percentage of radicals having vibrational energy above and below the lowest dissociation barrier, that to OH + propene; it accurately predicts the measured velocity distribution of the stable C$_{3}$H$_{6}$OH radicals. In addition, we use photofragment translational spectroscopy to detect several dissociation products of the unstable C$_{3}$H$_{6}$OH radicals: OH + propene, methyl + acetaldehyde, and ethyl + formaldehyde. We also use the angular momenta of the unstable radicals to estimate the energy partitioned to relative kinetic energy when they dissociate to OH + propene, which agrees very well with the data.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

English

Permalink

http://hdl.handle.net/2142/50780

DOI

https://doi.org/10.15278/isms.2014.WH05

Copyright and License Information

Copyright 2014 by the authors. Licensed under a Creative Commons Attribution 4.0 International License. http://creativecommons.org/licenses/by/4.0/

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