Reaction of O(3 P) Atoms with Benzene

The gas-phase reaction of O(3 P) atoms with benzene was investigated in a flow system in the pressure range of 50–100mbar and a temperature of 295 ± 2K with a focus on the product formation. O2 concentrations in the carrier gas were in the range of (7.7–84) × 1014 molecule cm−3. The primary stable products detected were phenol, benzene oxide/oxepin and a not identified compound with the probable composition C5H6O. The yields of phenol and benzene oxide/oxepin were 0.12 ± 0.02 and 0.26 ± 0.06, respectively, being not affected by the experimental conditions. For benzene oxide/oxepin, a rapid consecutive reaction with O(3 P) atoms was observed with a rate coefficient of k (295K) = (1.1 ± 0.1) × 10−10cm3 molecule−1s−1 measured at a pressure of 100mbar. A substance with the formula C6H6O2 (likely oxepin 4,5-epoxide or oxepin 2,3-epoxide), the isomers of muconaldehyde, as well as formic acid, acrolein and trans-butenedial were identified as products of the reaction of O(3 P) atoms with benzene oxide/oxepin.