Shock Tube Investigation of CH₃ + CH₃OCH₃

Abstract

The title reaction has been investigated in a diaphragmless shock tube by laser schlieren densitometry over the temperature range 1163–1629 K and pressures of 60, 120, and 240 Torr. Methyl radicals were produced by dissociation of 2,3-butanedione in the presence of an excess of dimethyl ether. Rate coefficients for CH₃ + CH₃OCH₃ were obtained from simulations of the experimental data yielding the following expression which is valid over the range 1100–1700 K: <i>k</i> = (10.19 ± 3.0)<i>T</i>^3.78 exp^(−4878/T) cm³ mol^–1s^–1. The experimental results are in good agreement with estimates by Curran and co-workers [Fischer, S. L.; Dryer, F. L.; Curran, H. J. <i>Int. J. Chem. Kinet.</i> <b>2000</b>, <i>32</i> (12), 713–740. Curran, H. J.; Fischer, S. L.; Dryer, F. L. <i>Int. J. Chem. Kinet.</i> <b>2000</b>, <i>32</i> (12), 741–759] but about a factor of 2.6 lower than those of Zhao et al. [Zhao, Z.; Chaos, M.; Kazakov, A.; Dryer, F. L. <i>Int. J. Chem. Kinet.</i> <b>2008</b>, <i>40</i> (1), 1–18]