Absolute rate constants and products of secondary steps in the atmospheric degradation of aromatics

Consecutive reactions of the adducts, aromatic-OH, with the atmospheric scavengers NO, NO2 and O2 are studied for aniline and with O2 for naphthalene by flash photolysis/resonance fluorescence (FP/RF). As with benzene, toluene, p-xylene, phenol, and m-cresol, the reaction of the adducts with O2 predominates under tropospheric conditions for aniline and naphthalene. The rate constant of the reaction of aniline-OH with NO2 at 330 K is 5X10-11 cm3s-1. the reaction aniline-OH + NO was found to be slower than 1X10-13 cm3s-1. The formation of HO2 following benzene-OH + O2 is studied by cycling experiments where HO2 is detected via HO2 + NO - OH + NO2. In contrast to the complex behaviour in the case of phenol a direct formation of HO2 from benzene-OH + O2 is consistent with our data.