Supporting data for Formation of Highly Oxidized Molecules from NO3 Radical Oxidation of Δ-3-Carene: A Computational Mechanism

NO3 radical oxidation of most monoterpenes is a significant source of secondary organic aerosol (SOA) in many regions influenced by both biogenic and anthropogenic emissions, but there are very few published mechanistic studies of NO3 chemistry beyond simple 1st generation products. Here, we present a computationally-derived mechanism detailing the unimolecular pathways available to the 2nd generation of peroxy radicals following NO3 oxidation of Δ-3-carene, defining generations based on the sequence of peroxy radicals formed rather than number of oxidant attacks. We assess five different types of unimolecular reactions, including peroxy and alkoxy radical (RO2 and RO) hydrogen shifts, RO­2 and RO ring closing (e.g. endoperoxide formation), and RO decomposition. Rate constants calculated using quantum chemical methods indicate that this chemical system has significant contribution from both bimolecular and unimolecular pathways. The dominant unimolecular reactions are endoperoxide forma...