Recombination of methyl radicals. 1. New data between 1175 and 1750 K in the falloff region
- Argonne National Lab., IL (United States)
- Earlham College, Richmond, IN (United States)
The rate coefficient for the recombination of methyl radicals, CH{sub 3} + CH{sub 3} {yields} C{sub 2}H{sub 6}, was measured in incident shock-wave experiments on azomethane (0.12-1.3%) in argon. Methyl radicals were detected at 46294 cm{sup -1} (215.94 nm in air) by the tunable-laser flash absorption technique. Postshock pressures between 114 and 230 kPa (1.13-2.27 atm) produced buffer gas concentrations between 5.4 x 10{sup 18} and 1.1 x 10{sup 19} cm{sup -3}. The cross section for optical absorption, the rate of dissociation of azomethane, and the rate coefficient of the recombinational reaction were determined simultaneously by least-squares analysis of methyl absorption profiles. The rate coefficient for the dissociation of azomethane from 850 to 1430 K is k{sub dis}(T) = 2.22 x 10{sup 39}T{sup -7.99} exp[C@-25920/T(K)] s{sup -1}. The temperature- dependent rate of recombination at 1.2 atm compares favorably with previous measurements. In terms of the phenomenological three-parameter equation of Kooji and the asymmetric Lorentzian broadening function of Gilbert et al., the recombination data from 296 to 1800 K is described by the equation given here. 37 refs., 6 figs., 3 tabs.
- OSTI ID:
- 199404
- Journal Information:
- Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 3 Vol. 100; ISSN JPCHAX; ISSN 0022-3654
- Country of Publication:
- United States
- Language:
- English
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