HO2˙ as a potential reactant for the bimolecular reaction of tert-butoxy radicals in the atmosphere.

Abstract

Alkoxy radicals are key intermediates in the atmospheric degradation of volatile organic compounds. For most alkoxy radicals, reaction with O2 is the primary loss mechanism; however, only α-hydrogen-bearing alkoxy radicals undergo a reaction with O2. Interestingly, if one considers an alkoxy radical that does not possess an α-hydrogen, reaction with O2 is unlikely. In the present work, we propose HO2˙ as a potential reactant for such alkoxy radicals. We have considered the tert-butoxy radical (tBuO˙) as a prototype for those alkoxy radicals that do not possess an α-hydrogen. By means of high-level quantum chemical calculations, we have studied the energetics of the tBuO˙ + HO2˙ reaction along with isomerization and decomposition pathways. Finally, we have discussed the possible atmospheric implications of all three paths in the atmosphere using reaction rate calculations.