Hydroxyl radical initiated oxidation of s-triazine: Hydrogen abstraction is faster than hydroxyl addition

Abstract

Reaction with the hydroxyl radical (HȮ) is the primary removal mechanism for organic compounds in the atmosphere, and an important process in combustion. Molecules with unsaturated carbon sites are thought to react with HȮ via a rapid addition mechanism, with little or no barrier; this results in short lifetimes relative to the saturated alkanes, which undergo slower abstraction reactions. Computational chemistry and reaction rate theory are used in this study to investigate the s-triazine + HȮ reaction. We report that HȮ addition at a carbon ring site proceeds with the largest known barrier for addition to an unsaturated carbon (9.8 kcal mol -1 at the G3X level of theory). Abstraction of a ..