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 cm 3 molecule −1 s −1 and k 1, nonane = (6.64 ± 1.36) × 10 −12 cm 3 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 k 2 = (4.95 ± 0.40) × 10 −12 cm 3 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 k 2 = (2.43 ± 0.52) × 10 −11 exp[(−481.2 ± 60)/T], respectively. © 2011 Wiley Periodicals, Inc. Int J Chem Kinet 43: 489–497, 2011