Investigation of the Gas-Phase Reaction of Nopinone with OH Radicals: Experimental and Theoretical Study

Monoterpenes are the most essential reactive biogenic volatile organic compounds. Their removal from atmosphere leads to formation of oxygenated compounds, such as nopinone (C9H14O), one important first-generation β-pinene oxidation products that play a pivotal role in environmental and biological applications. In this study, experimental theoretical rate coefficients were determined for gas-phase reaction with hydroxyl radicals (OH). The absolute coefficient was measured first time using cryogenically cooled cell along pulsed laser photolysis–laser-induced fluorescence technique at 298 K 7 Torr. hydrogen abstraction pathways found by electronic structure calculations determine favourable H-abstraction position. Pathway 5 (bridgehead position) more favourable, small barrier height −1.23 kcal/mol. calculated based on canonical variational transition state theory small-curvature tunnelling method (CVT/SCT) function temperature. average (1.74 × 10−11 cm3 molecule−1 s−1) good agreement value (2.2 s−1). Conclusively, results study pave way understand atmospheric chemistry OH radicals.