Criegee Intermediates in Autoxidation Reactions: Mechanistic Considerations

2021 ◽  
Author(s):  
J. Philipp Wagner
Keyword(s):  
Criegee Intermediates

scholarly journals Open questions on the reactivity of Criegee intermediates

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Rebecca L. Caravan ◽  
Michael F. Vansco ◽  
Marsha I. Lester
Keyword(s):  
Criegee Intermediates ◽  
Open Questions

scholarly journals Deep tunneling in the unimolecular decay of CH3CHOO Criegee intermediates to OH radical products

2016 ◽  
Vol 145 (23) ◽  
pp. 234308 ◽  
Author(s):  
Yi Fang ◽  
Fang Liu ◽  
Victoria P. Barber ◽  
Stephen J. Klippenstein ◽  
Anne B. McCoy ◽  
...  
Keyword(s):  
Oh Radical ◽  
Criegee Intermediates

scholarly journals Tunneling effects in the unimolecular decay of (CH3)2COO Criegee intermediates to OH radical products

2017 ◽  
Vol 146 (13) ◽  
pp. 134307 ◽  
Author(s):  
Yi Fang ◽  
Victoria P. Barber ◽  
Stephen J. Klippenstein ◽  
Anne B. McCoy ◽  
Marsha I. Lester
Keyword(s):  
Oh Radical ◽  
Criegee Intermediates

scholarly journals Direct observation of unimolecular decay of CH3CH2CHOO Criegee intermediates to OH radical products

2016 ◽  
Vol 145 (4) ◽  
pp. 044312 ◽  
Author(s):  
Yi Fang ◽  
Fang Liu ◽  
Stephen J. Klippenstein ◽  
Marsha I. Lester
Keyword(s):  
Direct Observation ◽  
Oh Radical ◽  
Criegee Intermediates

scholarly journals The oxidation regime and SOA composition in limonene ozonolysis: roles of different double bonds, radicals, and water

2018 ◽  
Vol 18 (20) ◽  
pp. 15105-15123 ◽  
Author(s):  
Yiwei Gong ◽  
Zhongming Chen ◽  
Huan Li
Keyword(s):  
Mass Fraction ◽  
Reaction Pathway ◽  
Performic Acid ◽  
Oh Radicals ◽  
Double Bonds ◽  
Criegee Intermediates ◽  
Volatile Organic ◽  
Partitioning Coefficients ◽  
Reaction With Water ◽  
Partitioning Behavior

Abstract. Volatile organic compounds play an important role in air quality and climate change, largely because they contribute to the formation of oxidizing compounds and secondary organic aerosol (SOA). In this study, a series of products, including peroxides and carbonyl compounds in both gaseous and particulate phases, were simultaneously detected to investigate the oxidation regime and SOA composition in limonene ozonolysis. The roles of different double bonds (DBs), radicals, and water were also examined. In our first investigation, we focused on representative oxidizing compounds produced in limonene ozonolysis, including stabilized Criegee intermediates (SCIs), OH radicals, and peroxides. The dependence of H2O2 and hydroxymethyl hydroperoxide (HMHP) formation on RH demonstrates that the reaction with water is an important reaction pathway for limonene SCIs, and the lower limit SCI yields of endocyclic and exocyclic DBs were estimated to be ∼0.24 and ∼0.43, respectively. The OH yield was determined by adding sufficient amounts of an OH scavenger, and the OH yields of endocyclic and exocyclic DBs were ∼0.65 and ∼0.24, respectively. These results indicate that in limonene ozonolysis the endocyclic DB is inclined to generate OH radicals through the hydroperoxide channel, while the exocyclic DB has a higher fraction of forming SCIs. Additionally, other gas-phase and particle-phase peroxides were also studied in this work. The formation of performic acid (PFA) and peracetic acid (PAA) was promoted significantly by increasing RH and the degree of oxidation, and the discrepancy between the experimental and model results suggested some missing formation pathways. Considerable generation of H2O2 from SOA in the aqueous phase was observed, especially at a high [O3] ∕ [limonene] ratio, which was mainly attributed to the hydration and decomposition of unstable peroxides in SOA such as peroxycarboxylic acids and peroxyhemiacetals. Different DBs and OH scavengers had a large impact on the particulate peroxides, and their stability indicated that the types of peroxides in SOA changed under different conditions. As for the contribution of peroxides to SOA, the results demonstrated that the mass fraction of particulate peroxides in limonene SOA was less than 0.2 at a low [O3] ∕ [limonene] ratio, while the mass fraction was 0.4–0.6 at a high [O3] ∕ [limonene] ratio. The partitioning behavior of peroxides showed that multi-generation oxidation helped produce more low-volatility peroxides, which partially explained the higher SOA yield. The partitioning behavior of carbonyls was also examined and the experimental partitioning coefficients (Kp) were found to be typically several orders of magnitude higher than the theoretical values. This study provided new insights into the oxidation regime and SOA composition in limonene ozonolysis, and limonene showed its specificity in many aspects when both endocyclic and exocyclic DBs were ozonated. We suggest that the atmospheric implications of terpenes containing more than one DB and the SOA composition, especially particulate peroxides, need further study.

scholarly journals Role of Criegee intermediates in the formation of sulfuric acid at a Mediterranean (Cape Corsica) site under influence of biogenic emissions

2021 ◽  
Vol 21 (17) ◽  
pp. 13333-13351
Author(s):  
Alexandre Kukui ◽  
Michel Chartier ◽  
Jinhe Wang ◽  
Hui Chen ◽  
Sébastien Dusanter ◽  
...  
Keyword(s):  
Steady State ◽  
Sulfuric Acid ◽  
Organic Compounds ◽  
Rate Coefficients ◽  
Oh Radicals ◽  
Additional Source ◽  
So2 Oxidation ◽  
Criegee Intermediates ◽  
Volatile Organic

Abstract. Reaction of stabilized Criegee intermediates (SCIs) with SO2 was proposed as an additional pathway of gaseous sulfuric acid (H2SO4) formation in the atmosphere, supplementary to the conventional mechanism of H2SO4 production by oxidation of SO2 in reaction with OH radicals. However, because of a large uncertainty in mechanism and rate coefficients for the atmospheric formation and loss reactions of different SCIs, the importance of this additional source is not well established. In this work, we present an estimation of the role of SCIs in H2SO4 formation at a western Mediterranean (Cape Corsica) remote site, where comprehensive field observations including gas-phase H2SO4, OH radicals, SO2, volatile organic compounds (VOCs) and aerosol size distribution measurements were performed in July–August 2013 as a part of the project ChArMEx (Chemistry-Aerosols Mediterranean Experiment). The measurement site was under strong influence of local emissions of biogenic volatile organic compounds, including monoterpenes and isoprene generating SCIs in reactions with ozone, and, hence, presenting an additional source of H2SO4 via SO2 oxidation by the SCIs. Assuming the validity of a steady state between H2SO4 production and its loss by condensation on existing aerosol particles with a unity accommodation coefficient, about 90 % of the H2SO4 formation during the day could be explained by the reaction of SO2 with OH. During the night the oxidation of SO2 by OH radicals was found to contribute only about 10 % to the H2SO4 formation. The accuracy of the derived values for the contribution of OH + SO2 reaction to the H2SO4 formation is limited mostly by a large, at present factor of 2, uncertainty in the OH + SO2 reaction rate coefficient. The contribution of the SO2 oxidation by SCIs to the H2SO4 formation was evaluated using available measurements of unsaturated VOCs and steady-state SCI concentrations estimated by adopting rate coefficients for SCI reactions based on structure–activity relationships (SARs). The estimated concentration of the sum of SCIs was in the range of (1–3) × 103 molec. cm−3. During the day the reaction of SCIs with SO2 was found to account for about 10 % and during the night for about 40 % of the H2SO4 production, closing the H2SO4 budget during the day but leaving unexplained about 50 % of the H2SO4 formation during the night. Despite large uncertainties in used kinetic parameters, these results indicate that the SO2 oxidation by SCIs may represent an important H2SO4 source in VOC-rich environments, especially during nighttime.

scholarly journals Measurements of the OH radical yield from the ozonolysis of biogenic alkenes: A potential interference with laser-induced fluorescence measurements of ambient OH

2017 ◽  
Author(s):  
Pamela Rickly ◽  
Philip S. Stevens
Keyword(s):  
Flow Reactor ◽  
Laser Induced Fluorescence ◽  
Fluorescence Measurements ◽  
Criegee Intermediates ◽  
Volatile Organic ◽  
Forested Areas ◽  
Rigorous Test ◽  
Reactor Operating ◽  
Gas Expansion ◽  
Radical Yield

Abstract. Reactions of the hydroxyl radical (OH) play a central role in the chemistry of the atmosphere, and measurements of its concentration can provide a rigorous test of our understanding of atmospheric oxidation. Several recent studies have shown large discrepancies between measured and modeled OH concentrations in forested areas impacted by emissions of biogenic volatile organic compounds (BVOCs), where modeled concentrations were significantly lower than measurements. A potential reason for some of these discrepancies involves interferences associated with the measurement of OH using the Laser-Induced Fluorescence – Fluorescence Assay with Gas Expansion (LIF-FAGE) technique in these environments. In this study, a turbulent flow reactor operating at atmospheric pressure was coupled to a LIF-FAGE cell and the OH signal produced from the ozonolysis of several BVOCs was measured. To distinguish between OH produced from the ozonolysis reactions and any OH artefact produced inside the LIF-FAGE cell, an external chemical scrubbing technique was used, allowing for the direct measurement of any interference. An interference under high ozone and BVOC concentrations was observed that was not laser generated and was independent of the ozonolysis reaction time. Addition of acetic acid to the reactor eliminated the interference, suggesting that the source of the interference in these experiments involved the decomposition of stabilized Criegee intermediates inside the FAGE detection cell.

scholarly journals The ozonolysis of primary aliphatic amines in fine particles

2008 ◽  
Vol 8 (5) ◽  
pp. 1181-1194 ◽  
Author(s):  
J. Zahardis ◽  
S. Geddes ◽  
G. A. Petrucci
Keyword(s):  
Fine Particles ◽  
Reaction System ◽  
Tropospheric Chemistry ◽  
Ozone Exposure ◽  
Surface Barrier ◽  
Secondary Amide ◽  
Tertiary Amide ◽  
Aerosol Mass ◽  
Criegee Intermediates ◽  
Species Specific

Abstract. The oxidative processing by ozone of the particulate amines octadecylamine (ODA) and hexadecylamine (HDA) is reported. Ozonolysis of these amines resulted in strong NO2– and NO3– ion signals that increased with ozone exposure as monitored by photoelectron resonance capture ionization aerosol mass spectrometry. These products suggest a mechanism of progressive oxidation of the particulate amines to nitroalkanes. Additionally, a strong ion signal at 125 m/z is assigned to the ion NO3– (HNO3). For ozonized mixed particles containing ODA or HDA + oleic acid (OL), with pO3≥3×10–7 atm, imine, secondary amide, and tertiary amide products were measured. These products most likely arise from reactions of amines with aldehydes (for imines) and stabilized Criegee intermediates (SCI) or secondary ozonides (for amides) from the fatty acid. The routes to amides via SCI and/or secondary ozonides were shown to be more important than comparable amide forming reactions between amines and organic acids, using azelaic acid as a test compound. Finally, direct evidence is provided for the formation of a surface barrier in the ODA + OL reaction system that resulted in the retention of OL at high ozone exposures (up to 10−3 atm for 17 s). This effect was not observed in HDA + OL or single component OL particles, suggesting that it may be a species-specific surfactant effect from an in situ generated amide or imine. Implications to tropospheric chemistry, including particle bound amines as sources of oxidized gas phase nitrogen species (e.g.~NO2, NO3), formation of nitrogen enriched HULIS via ozonolysis of amines and source apportionment are discussed.

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