Rate constants for the gas phase reactions of O 3 with the natural hydrocarbons isoprene and α- and β-pinene

Abstract

Rate constants have been determined for the gas phase reaction of ozone with the naturally emitted hydrocarbons isoprene and α-pinene over the temperature range ~ 276 to 324 K, and with β-pinene at 296K. At 296 K the rate constants obtained are ( × 10 17 cm 3 molecule −1s −1): isoprene, 1.17; α-pinene, 8.4 and β-pinene, 2.1. The rate constants for α- and β-pinene are significantly lower than previous literature values, thus increasing the importance of reaction with the OH radical as an atmospheric removal process for these two hydrocarbons.