Kinetic study of OH radical reaction with n‐heptane and n‐hexane at 240–340K using the relative rate/discharge flow/mass spectrometry (RR/DF/MS) technique

The kinetics of reactions of OH radical with n‐heptane and n‐hexane over a temperature range of 240–340K has been investigated using the relative rate combined with discharge flow/mass spectrometry (RR/DF/MS) technique. The rate constant for the reaction of OH radical with n‐heptane was measured with both n‐octane and n‐nonane as references. At 298K, these rate constants were determined to be k_{1, octane} = (6.68 ± 0.48) × 10^?12 cm³ molecule^?1 s^?1 and k_{1, nonane} = (6.64 ± 1.36) × 10^?12 cm³ molecule^?1 s^?1, respectively, which are in very good agreement with the literature values. The rate constant for reaction of n‐hexane with the OH radical was determined to be k₂ = (4.95 ± 0.40) × 10^?12 cm³ molecule^?1 s^?1 at 298K using n‐heptane as a reference. The Arrhenius expression for these chemical reactions have been determined to be k_{1, octane} = (2.25 ± 0.21) × 10^?11 exp(?293 ± 37)/T] and k₂ = (2.43 ± 0.52) × 10^?11 exp(?481.2 ± 60)/T], respectively. © 2011 Wiley Periodicals, Inc. Int J Chem Kinet 43: 489–497, 2011