## Abstract

Laser photolysis/laser-induced fluorescence (LIF) is employed to investigate the kinetics of the reactions, OH+CH_{3}NO_{2}, OD+CH_{3}NO_{2}, and OD+CD_{3}NO_{2} over the temperature range 296-671 K. Photolysis of nitromethane at 266 nm generates OH or OD radicals. Rate constants are independent of pressure over the range 100-300 Torr. The following Arrhenius equations are calculated: k =(1.1±0.4)x10^{-12} exp[-(2730±290 cal/mol)/RT] cm^{3} s^{-1} for OH, OD+CH_{3}NO_{2} and k =(5.3±2.4)×10^{-13} exp[-(2860±340 cal/mol)/RT] cm^{3} s^{-1} for OD+CD_{3}NO_{2}. A hydrogen atom abstraction mechanism is supported by evidence from isotopic studies, transition-state theory calculations, absence of pressure effects, known energetics, and measured activation energies. Transition-state theory (TST) calculations predict non-Arrhenius behavior as temperatures approach the combustion regime. The TST calculation is fit by the equation, k = 4.37 × 10^{-20} T^{2.4} exp(- 340/T) cm^{3} s^{-1} over the temperature range 200-2000 K.

Original language | English |
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Pages (from-to) | 319-325 |

Number of pages | 7 |

Journal | Chemical Physics |

Volume | 120 |

Issue number | 2 |

DOIs | |

State | Published - 15 Feb 1988 |