The rate constants for the reaction of the hydroxyl radical with benzene

Values of the pressure-dependent second-order rate constant for the reaction OH + C6H6+ M → C6H6OH + M have been measured using a discharge-flow system operating at 295 K over a pressure range of 60–1200 Pa. The OH concentration was monitored by resonance fluorescence and helium was used as the carrier gas. This is the first application of discharge-flow methods to this reaction. The results are in general agreement with those from other techniques. Extrapolation to obtain the low-pressure limiting value of the rate constant is difficult because of the scatter in the data at higher pressures. A range of values is obtained leading to a recommended value of (1 ± 0.8)× 1013 dm6 mol–2 s–1 for k°.