Kinetics of the C3H7O2 + NO reaction: Temperature dependence of the overall rate constant and the i-C3H7ONO2 branching channel

Abstract

The temperature dependence of the overall rate constant for the C3H7O2 + NO reaction and the rate constant for the minor branching channel resulting in the production of i-C3H7ONO2 have been measured using the turbulent flow technique with high-pressure chemical ionization mass spectrometry for the detection of reactants and products. The temperature dependence of the overall rate constant for the C3H7O2 + NO reaction was investigated between 298 and 213 K at 100 Torr pressure, and the data were fit by the following Arrhenius expression (with 2 standard deviation error limits indicated):  × 10-12 exp[(268 ± 56)/T] cm3 molecule-1 s-1. This expression agrees well with previous isomer-specific measurements of the n-C3H7ONO2 and i-C3H7O2 + NO rate constants made at lower pressures. The temperature dependence of the rate constant for the minor reaction channel i-C3H7O2 + NO → i-C3H7ONO2 was investigated between 298 and 213 K at 100 Torr pressure. The following Arrhenius expression was determined for the minor channel:  × 10-16 exp[(1380 ± 230)/T] cm3 molecule-1 s-1. The Arrhenius expressions for the overall rate and the i-C3H7ONO2 producing channel indicate a branching ratio of about 0.006 at 298 K and 0.020 at 213 K at 100 Torr pressure, which is in good agreement with the predictions of a recently revised empirical model for alkyl nitrate branching ratios.

Publisher

American Chemical Society

Publication Date

5-1-2003

Publication Title

Journal of Physical Chemistry A

Department

Chemistry and Biochemistry

Document Type

Article

DOI

https://dx.doi.org/10.1021/jp026134b

Keywords

Nox-air photooxidations, Alkyl nitrate formation, Peroxy radicals, N-alkanes

Language

English

Format

text

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