Kinetics of the gas‐phase reactions of OH radicals with alkyl nitrates at 299 ± 2 K

Abstract

AbstractRelative rate constants for the gas‐phase reactions of OH radicals with a series of alkyl nitrates have been determined at 299 ± 2 K, using methyl nitrite photolysis in air as a source of OH radicals. Using a rate constant for the reaction of OH radicals with cyclohexane of 7.57 × 10−12 cm3/molec·s, the rate constants obtained are (× 1012 cm3/molec·s): 2‐propyl nitrate, 0.18 ± 0.05; 1‐butyl nitrate, 1.42 ± 0.11; 2‐butyl nitrate, 0.69 ± 0.10; 2‐pentyl nitrate, 1.87 ± 0.12; 3‐pentyl nitrate, 1.13 ± 0.20; 2‐hexyl nitrate, 3.19 ± 0.16; 3‐hexyl nitrate, 2.72 ± 0.22; 3‐heptyl nitrate, 3.72 ± 0.43; and 3‐octyl nitrate, 3.91 ± 0.80. These rate constants, which are the first reported for the alkyl nitrates, are significantly lower than those for the parent alkanes, and a formula, based on the numbers of the various types of CH bonds in the alkyl nitrates, is derived for rate constant estimation purposes.