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.

[1]  Luc Vereecken,et al.  Nontraditional (Per)oxy Ring-Closure Paths in the Atmospheric Oxidation of Isoprene and Monoterpenes , 2004 .

[2]  C. N. Hewitt,et al.  A global model of natural volatile organic compound emissions , 1995 .

[3]  J. Müller,et al.  A group contribution method for estimating the vapour pressures of α-pinene oxidation products , 2005 .

[4]  J. Peeters,et al.  The 1,5-H-shift in 1-butoxy: A case study in the rigorous implementation of transition state theory for a multirotamer system , 2003 .

[5]  I. Hermans,et al.  Kinetics of alpha-hydroxy-alkylperoxyl radicals in oxidation processes. HO2*-initiated oxidation of ketones/aldehydes near the tropopause. , 2005, The journal of physical chemistry. A.

[6]  I. Hermans,et al.  Tropopause chemistry revisited: HO2*-initiated oxidation as an efficient acetone sink. , 2004, Journal of the American Chemical Society.

[7]  Jiwen Fan,et al.  Theoretical study of OH addition to α-pinene and β-pinene , 2005 .

[8]  C. Vinckier,et al.  Determination of the oxidation products of the reaction between alpha-pinene and hydroxyl radicals by high-performance liquid chromatography. , 2001, Journal of chromatography. A.

[9]  S. M. Aschmann,et al.  Products of reaction of OH radicals with α‐pinene , 2002 .

[10]  A. Wisthaler,et al.  Measurements of acetone and other gas phase product yields from the OH-initiated oxidation of terpenes by proton-transfer-reaction mass spectrometry (PTR-MS) , 2001 .

[11]  Y. Rudich,et al.  Product studies of the OH‐ and ozone‐initiated oxidation of some monoterpenes , 2000 .

[12]  J. Peeters,et al.  A Generalized Structure-Activity Relationship for the Decomposition of (Substituted) Alkoxy Radicals , 2004 .

[13]  J. Peeters,et al.  Alpha-pinene oxidation by OH: simulations of laboratory experiments , 2004 .

[14]  Erik Swietlicki,et al.  Organic aerosol and global climate modelling: a review , 2004 .

[15]  Luc Vereecken,et al.  The detailed mechanism of the OH-initiated atmospheric oxidation of α-pinene: a theoretical study , 2001 .

[16]  S. M. Aschmann,et al.  Alkyl Nitrate, Hydroxyalkyl Nitrate, and Hydroxycarbonyl Formation from the NOx−Air Photooxidations of C5−C8 n-Alkanes , 2001 .

[17]  S. M. Aschmann,et al.  Products of the gas phase reactions of the OH radical with α‐ and β‐pinene in the presence of NO , 1998 .

[18]  H. Hakola,et al.  Product formation from the gas-phase reactions of OH radicals and O3 with a series of monoterpenes , 1994 .

[19]  J. Peeters,et al.  Theoretical Study of the Formation of Acetone in the OH-Initiated Atmospheric Oxidation of α-Pinene , 2000 .

[20]  I. Barnes,et al.  Product study and mechanisms of the reactions of α‐pinene and of pinonaldehyde with OH radicals , 1999 .

[21]  W. Carter,et al.  Evaluation of alkene degradation in the detailed tropospheric chemistry mechanism, MCM v3, using environmental chamber data , 2006 .

[22]  M. Jenkin,et al.  The tropospheric degradation of volatile organic compounds: a protocol for mechanism development , 1997 .

[23]  H. Akimoto,et al.  Reactions of OH with α‐pinene and β‐pinene in air: Estimate of global CO production from the atmospheric oxidation of terpenes , 1991 .

[24]  John H. Seinfeld,et al.  Gas-Phase Ozone Oxidation of Monoterpenes: Gaseous and Particulate Products , 1999 .

[25]  Giuseppe A. Petrucci,et al.  Direct observation of polymerization in the oleic acid–ozone heterogeneous reaction system by photoelectron resonance capture ionization aerosol mass spectrometry , 2006 .

[26]  D. R. Worsnop,et al.  under a Creative Commons License. Atmospheric Chemistry , 2006 .

[27]  S. Koch,et al.  Formation of new particles in the gas phase ozonolysis of monoterpenes , 2000 .

[28]  W. Boullart,et al.  Structure-activity relationship for the addition of OH to (poly)alkenes: site-specific and total rate constants. , 2007, The journal of physical chemistry. A.