Rate coefficients for the gas-phase reaction of OH radicals with selected dihydroxybenzenes and benzoquinones

Abstract

Rate coefficients have been determined for the gas-phase reaction of the hydroxyl (OH) radical with the aromatic dihydroxy compounds 1,2-dihydroxybenzene, 1,2-dihydroxy-3-methylbenzene and 1,2-dihydroxy-4-methylbenzene as well as the two benzoquinone derivatives 1,4-benzoquinone and methyl-1,4-benzoquinone. The measurements were performed in a large-volume photoreactor at (300 ± 5) K in 760 Torr of synthetic air using the relative kinetic technique. The rate coefficients obtained using isoprene, 1,3-butadiene, and E-2-butene as reference hydrocarbons are kOH(1,2-dihydroxybenzene) = (1.04 ± 0.21) × 10−10 cm3 s−1, kOH(1,2-dihydroxy-3-methylbenzene) = (2.05 ± 0.43) × 10−10 cm3 s−1, kOH(1,2-dihydroxy-4-methylbenzene) = (1.56 ± 0.33) × 10−10 cm3 s−1, kOH(1,4-benzoquinone) = (4.6 ± 0.9) × 10−12 cm3 s−1, kOH(methyl-1,4-benzoquinone) = (2.35 ± 0.47) × 10−11 cm3 s−1. This study represents the first determination of OH radical reaction-rate coefficients for these compounds. © 2000 John Wiley & Sons, Inc. Int J Chem Kinet 32: 696–702, 2000