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Formation of dimethylketene and methacrolein by reaction of the CH radical with acetone
Faculty of Science, Medicine and Health - Papers
  • Fabien Goulay, West Virginia University
  • Adeeb Derakhshan, West Virginia University
  • Eamonn Maher, West Virginia University
  • Adam J Trevitt, University of Wollongong
  • John D Savee, Sandia National Laboratories,Combustion Research Facility
  • Adam M Scheer, Sandia National Laboratories
  • David L Osborn, Sandia National Laboratories
  • Craig A Taatjes, Sandia National Laboratories
RIS ID
75818
Publication Date
1-1-2013
Publication Details

Goulay, F., Derakhshan, A., Maher, E., Trevitt, A. J., Savee, J. D., Scheer, A. M., Osborn, D. L. & Taatjes, C. A. (2013). Formation of dimethylketene and methacrolein by reaction of the CH radical with acetone. Physical Chemistry Chemical Physics, 15 (11), 4049-4058.

Abstract
The reaction of the methylidyne radical (CH) with acetone ((CH3)2CO) is studied at room temperature and at a pressure of 4 Torr (533.3 Pa) using a multiplexed photoionization mass spectrometer coupled to the tunable vacuum ultraviolet synchrotron radiation of the Advanced Light Source at Lawrence Berkeley National Laboratory. The CH radicals are generated by 248 nm multiphoton photolysis of bromoform and react with acetone in an excess of helium and nitrogen gas flow. The main observed reaction exit channel is elimination of a hydrogen atom to form C4H6O isomers. Analysis of photoionization spectra identifies dimethylketene and methacrolein as the only H-elimination products. The best fit to the data gives branching ratios of 0.68 ± 0.14 for methacrolein and 0.32 ± 0.07 for dimethylketene. A methylketene spectrum measured here is used to reanalyze the photoionization spectrum obtained at m/z = 56 for the CH + acetaldehyde reaction, (Goulay et al., J. Phys. Chem. A, 2012, 116, 6091) yielding new H-loss branching ratios of 0.61 ± 0.12 for acrolein and 0.39 ± 0.08 for methylketene. The contribution from methyleneoxirane to the reaction product distribution is revised to be negligible. Coupled with additional product detection for the CD + acetone reaction, these observations pave the way for development of general set of reaction mechanisms for the addition of CH to compounds containing an acetyl subgroup.
Grant Number
ARC/DP1094135
Citation Information
Fabien Goulay, Adeeb Derakhshan, Eamonn Maher, Adam J Trevitt, et al.. "Formation of dimethylketene and methacrolein by reaction of the CH radical with acetone" (2013)
Available at: http://works.bepress.com/adam_trevitt/11/