Atmospheric Oxidation of C ₁₂ –C ₁₄ n -Alkylcyclohexanes Initiated by Cl Atoms and OH Radicals: Mechanistic Insights, Kinetics, and the Inhibiting Effect of Water

, respectively, showing a slight increasing trend with carbon-chain length. Notably, the presence of a single water molecule was found to significantly increase the energy barriers for H-abstraction, indicating that water vapor exerts a negative catalytic effect on these atmospheric oxidation reactions. This finding suggests that under high-humidity conditions, the gas-phase oxidation of such IVOCs may be slower than currently predicted, with potential implications for SOA formation estimates. By elucidating the mechanistic details and kinetic parameters for this important class of IVOCs, this work provides a theoretical foundation for improving chemical mechanisms in atmospheric models.