skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Dynamics of H abstraction from alcohols (CH3OH, C2H5OH and 2-C3H7OH) using velocity map imaging in crossed molecular beams

Abstract

The crossed beam reactions of ground state Cl ({sup 2}P{sub 3/2}) atoms with alcohols (CH{sub 3}OH, C{sub 2}H{sub 5}OH and 2-C{sub 3}H{sub 7}OH) have been studied using the technique of velocity map imaging (VELMI). The corresponding hydroxyalkyl radical was detected via single photon ionization using 157 nm laser light. The double differential cross sections were obtained at collision energies of 8.7 kcal/mol for methanol, 6.0 and 9.7 kcal/mol for ethanol, and 11.9 kcal/mol for 2-propanol. In all cases, the scattering was predominantly in the backward-sideways direction suggesting direct rebound dynamics, with varying amounts of sideways-scattering. In the case of methanol, the angular distributions were predominantly in the sideways-backward direction with respect to the incoming alcohol beam. Scattering was into the backward hemisphere at the lower collision energy for ethanol, with enhancement of sideways scattering with an increase in collision energy. Isoropanol gave scattering predominantly in the backward direction. Coupling between the translational energy and angular distributions was particularly significant for ethanol at the lower collision energy. All of the translational energy distributions peaked at about 6 kcal/mol and on average 30-40% of the available energy was deposited into product translation for all the alcohols studied. These results are contrasted withmore » previous H abstraction studies performed on Cl-hydrocarbon systems. A case is made for the technique of vacuum ultraviolet one-photon ionization in conjunction with VELMI being useful in studying the reaction dynamics for many polyatomic systems.« less

Authors:
; ;
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
Chemical Sciences Division
OSTI Identifier:
1008321
Report Number(s):
LBNL-44340
TRN: US201106%%399
DOE Contract Number:  
DE-AC02-05CH11231
Resource Type:
Journal Article
Journal Name:
Physical Chemistry Chemical Physics
Additional Journal Information:
Journal Name: Physical Chemistry Chemical Physics
Country of Publication:
United States
Language:
English
Subject:
43; ALCOHOLS; ANGULAR DISTRIBUTION; ATOMS; COLLIDING BEAMS; DIFFERENTIAL CROSS SECTIONS; ENERGY SPECTRA; ETHANOL; GROUND STATES; IONIZATION; LASERS; METHANOL; MOLECULAR BEAMS; PHOTONS; RADICALS; SCATTERING; VELOCITY

Citation Formats

Ahmed, M., Peterka, D.S., and Suits, A.G. Dynamics of H abstraction from alcohols (CH3OH, C2H5OH and 2-C3H7OH) using velocity map imaging in crossed molecular beams. United States: N. p., 1999. Web.
Ahmed, M., Peterka, D.S., & Suits, A.G. Dynamics of H abstraction from alcohols (CH3OH, C2H5OH and 2-C3H7OH) using velocity map imaging in crossed molecular beams. United States.
Ahmed, M., Peterka, D.S., and Suits, A.G. Wed . "Dynamics of H abstraction from alcohols (CH3OH, C2H5OH and 2-C3H7OH) using velocity map imaging in crossed molecular beams". United States. https://www.osti.gov/servlets/purl/1008321.
@article{osti_1008321,
title = {Dynamics of H abstraction from alcohols (CH3OH, C2H5OH and 2-C3H7OH) using velocity map imaging in crossed molecular beams},
author = {Ahmed, M. and Peterka, D.S. and Suits, A.G.},
abstractNote = {The crossed beam reactions of ground state Cl ({sup 2}P{sub 3/2}) atoms with alcohols (CH{sub 3}OH, C{sub 2}H{sub 5}OH and 2-C{sub 3}H{sub 7}OH) have been studied using the technique of velocity map imaging (VELMI). The corresponding hydroxyalkyl radical was detected via single photon ionization using 157 nm laser light. The double differential cross sections were obtained at collision energies of 8.7 kcal/mol for methanol, 6.0 and 9.7 kcal/mol for ethanol, and 11.9 kcal/mol for 2-propanol. In all cases, the scattering was predominantly in the backward-sideways direction suggesting direct rebound dynamics, with varying amounts of sideways-scattering. In the case of methanol, the angular distributions were predominantly in the sideways-backward direction with respect to the incoming alcohol beam. Scattering was into the backward hemisphere at the lower collision energy for ethanol, with enhancement of sideways scattering with an increase in collision energy. Isoropanol gave scattering predominantly in the backward direction. Coupling between the translational energy and angular distributions was particularly significant for ethanol at the lower collision energy. All of the translational energy distributions peaked at about 6 kcal/mol and on average 30-40% of the available energy was deposited into product translation for all the alcohols studied. These results are contrasted with previous H abstraction studies performed on Cl-hydrocarbon systems. A case is made for the technique of vacuum ultraviolet one-photon ionization in conjunction with VELMI being useful in studying the reaction dynamics for many polyatomic systems.},
doi = {},
journal = {Physical Chemistry Chemical Physics},
number = ,
volume = ,
place = {United States},
year = {1999},
month = {9}
}