Low-volatility poly-oxygenates in the OH-initiated atmospheric oxidation of alpha-pinene: impact of non-traditional peroxyl radical chemistry.
Following new insights on non-traditional peroxyl radical chemistry, we present an update to our earlier OH-initiated alpha-pinene degradation mechanism (Peeters et al., Phys. Chem. Chem. Phys., 2001, 3, 5489), incorporating ring closure reactions and a fast H-shift isomerization in certain key peroxyl and oxy radical intermediates. These changes, affecting only a single branch of the comprehensive mechanism and based on extensive quantum-chemical and theoretical kinetic calculations, show significant formation, approximately 20% overall, of poly-oxygenated (hydro)peroxides in atmospheric conditions. These low-volatility compounds are expected to have a significant impact on aerosol formation, and are believed to be the high-mass product compounds observed in available experimental work. The proposed changes also affect the predicted acetone yield, matching the experimental data closely.
Vereecken
L
L
University of Leuven, Department of Chemistry, Celestijnenlaan 200F, B-3001 Leuven, Belgium. Luc.Vereecken@chem.kuleuven.be
Müller
J F
JF
Peeters
J
J
D000096:Acetone / Q000737:chemistry; D001272:Atmosphere / Q000737:chemistry*; D000081008:Bicyclic Monoterpenes; D006878:Hydroxides / Q000737:chemistry*; D039821:Monoterpenes / Q000737:chemistry*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D010545:Peroxides / Q000737:chemistry*; D014835:Volatilization
D000081008:Bicyclic Monoterpenes; D006878:Hydroxides; D039821:Monoterpenes; D010545:Peroxides; D000096:Acetone; C049375:perhydroxyl radical; C031356:hydroxide ion; C005451:alpha-pinene; D010100:Oxygen