Adduct formation of OH radicals with Benzene, Toluene, and Phenol and consecutive reactions of the adducts with NOx and O2

The formation of the adducts of OH with benzene, toluene and phenol and consecutive reactions of the adducts with NO, NO2 and 02 are investigated in the temperature range from 298-374 K employing the flash photolysis/resonance fluorescence technique in Ar at 133 mbar. Three reaction channels: abstraction of H by OH, addition of OH and unimolecular decomposition of the adduct are distinguished in overlapping temperature ranges. Rate constants and preliminary Arrhenius parameters are obtained for these channels for benzene, toluene and phenol. The reactions of the adducts with NO are very slow and can be neglected in all three cases. Preliminary determinations of the adduct reactivities against 02 for benzene and toluene near room temperature indicate that this path predominates under tropospheric conditions. The results for 02 are confirmed by direct observations of the adduct benzene-OH by the cw UV-laser longpath absorption technique.