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Pasik D, Frandsen BN, Meder M, Iyer S, Kurtén T, Myllys N. Gas-Phase Oxidation of Atmospherically Relevant Unsaturated Hydrocarbons by Acyl Peroxy Radicals. J Am Chem Soc 2024; 146:13427-13437. [PMID: 38712858 DOI: 10.1021/jacs.4c02523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
This study assesses the atmospheric impact of reactions between unsaturated hydrocarbons such as isoprene and monoterpenes and peroxy radicals containing various functional groups. We find that reactions between alkenes and acyl peroxy radicals have reaction rates high enough to be feasible in the atmosphere and lead to high molar mass accretion products. Moreover, the reaction between unsaturated hydrocarbons and acyl peroxy radicals leads to an alkyl radical, to which molecular oxygen rapidly adds. This finding is confirmed by both theoretical calculations and experiments. The formed perester peroxy radical may either undergo further H-shift reactions or react bimolecularly. The multifunctional oxygenated compounds formed through acyl peroxy radical + alkene reactions are potentially important contributors to particle formation and growth. Thus, acyl peroxy radical-initiated oxidation chemistry may need to be included in atmospheric models.
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Affiliation(s)
- Dominika Pasik
- Department of Chemistry, University of Helsinki, Helsinki 00014, Finland
- Institute for Atmospheric and Earth System Research, University of Helsinki, Helsinki 00014, Finland
| | - Benjamin N Frandsen
- Department of Chemistry, University of Helsinki, Helsinki 00014, Finland
- Aerosol Physics Laboratory, Tampere University, Tampere 33014, Finland
| | - Melissa Meder
- Institute for Atmospheric and Earth System Research, University of Helsinki, Helsinki 00014, Finland
| | - Siddharth Iyer
- Aerosol Physics Laboratory, Tampere University, Tampere 33014, Finland
| | - Theo Kurtén
- Department of Chemistry, University of Helsinki, Helsinki 00014, Finland
- Institute for Atmospheric and Earth System Research, University of Helsinki, Helsinki 00014, Finland
| | - Nanna Myllys
- Department of Chemistry, University of Helsinki, Helsinki 00014, Finland
- Institute for Atmospheric and Earth System Research, University of Helsinki, Helsinki 00014, Finland
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Abstract
The utility of high energy density materials (HEDMs) comes from their thermodynamic properties which arise from specific structural features that contribute to energy storage. Studies of such structural features seek to increase our understanding of these energy storage mechanisms in order to further enhance their properties. High-nitrogen-containing HEDMs are of particular interest because they are less toxic than traditional HEDMs. Pentazole is the largest of the nitrogen rings which has been synthesized and considered for an HEDM; however, few experimental studies exist due to the difficulty involved in the synthesis, and most previous theoretical studies employed composite methods where lower level geometries were used with higher level methods. Here, the decomposition reaction of pentazole is studied. Geometries, fundamental frequencies, and energies for each of the stationary points of the decomposition pathway are computed using ab initio methods up to CCSDT(Q). Decomposition rates are calculated over a range of temperatures using canonical transition state theory in order to determine the kinetic stability of pentazole. Based on the present results, it would be difficult for pentazole to act as an HEDM, requiring temperatures close to 200 K to achieve a suitable level of stability.
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Affiliation(s)
- Henry F Mull
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Justin M Turney
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Gary E Douberly
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Henry F Schaefer
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, United States
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Zuraski K, Hui AO, Grieman FJ, Darby E, Møller KH, Winiberg FAF, Percival CJ, Smarte MD, Okumura M, Kjaergaard HG, Sander SP. Acetonyl Peroxy and Hydro Peroxy Self- and Cross-Reactions: Kinetics, Mechanism, and Chaperone Enhancement from the Perspective of the Hydroxyl Radical Product. J Phys Chem A 2020; 124:8128-8143. [PMID: 32852951 DOI: 10.1021/acs.jpca.0c06220] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Pulsed laser photolysis coupled with infrared (IR) wavelength modulation spectroscopy and ultraviolet (UV) absorption spectroscopy was used to study the kinetics and branching fractions for the acetonyl peroxy (CH3C(O)CH2O2) self-reaction and its reaction with hydro peroxy (HO2) at a temperature of 298 K and pressure of 100 Torr. Near-IR and mid-IR lasers simultaneously monitored HO2 and hydroxyl, OH, respectively, while UV absorption measurements monitored the CH3C(O)CH2O2 concentrations. The overall rate constant for the reaction between CH3C(O)CH2O2 and HO2 was found to be (5.5 ± 0.5) × 10-12 cm3 molecule-1 s-1, and the branching fraction for OH yield from this reaction was directly measured as 0.30 ± 0.04. The CH3C(O)CH2O2 self-reaction rate constant was measured to be (4.8 ± 0.8) × 10-12 cm3 molecule-1 s-1, and the branching fraction for alkoxy formation was inferred from secondary chemistry as 0.33 ± 0.13. An increase in the rate of the HO2 self-reaction was also observed as a function of acetone (CH3C(O)CH3) concentration which is interpreted as a chaperone effect, resulting from hydrogen-bond complexation between HO2 and CH3C(O)CH3. The chaperone enhancement coefficient for CH3C(O)CH3 was determined to be kA″ = (4.0 ± 0.2) × 10-29 cm6 molecule-2 s-1, and the equilibrium constant for HO2·CH3C(O)CH3 complex formation was found to be Kc(R14) = (2.0 ± 0.89) × 10-18 cm3 molecule-1; from these values, the rate constant for the HO2 + HO2·CH3C(O)CH3 reaction was estimated to be (2 ± 1) × 10-11 cm3 molecule-1 s-1. Results from UV absorption cross-section measurements of CH3C(O)CH2O2 and prompt OH radical yields arising from possible oxidation of the CH3C(O)CH3-derived alkyl radical are also discussed. Using theoretical methods, no likely pathways for the observed prompt OH radical formation have been found and the prompt OH radical yields thus remain unexplained.
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Affiliation(s)
- Kristen Zuraski
- NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, United States
| | - Aileen O Hui
- Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, United States
| | - Fred J Grieman
- NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, United States.,Seaver Chemistry Laboratory, Pomona College, Claremont, California 91711, United States
| | - Emily Darby
- Seaver Chemistry Laboratory, Pomona College, Claremont, California 91711, United States
| | - Kristian H Møller
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, Copenhagen Ø DK-2100, Denmark
| | - Frank A F Winiberg
- NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, United States
| | - Carl J Percival
- NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, United States
| | - Matthew D Smarte
- Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, United States
| | - Mitchio Okumura
- Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, United States
| | - Henrik G Kjaergaard
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, Copenhagen Ø DK-2100, Denmark
| | - Stanley P Sander
- NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, United States
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Møller KH, Berndt T, Kjaergaard HG. Atmospheric Autoxidation of Amines. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:11087-11099. [PMID: 32786344 DOI: 10.1021/acs.est.0c03937] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Autoxidation has been acknowledged as a major oxidation pathway in a broad range of atmospherically important compounds including isoprene, monoterpenes, and very recently, dimethyl sulfide. Here, we present a high-level theoretical multiconformer transition-state theory study of the atmospheric autoxidation in amines exemplified by the atmospherically important trimethylamine (TMA) and dimethylamine and generalized by the study of the larger diethylamine. Overall, we find that the initial hydrogen shift reactions have rate coefficients greater than 0.1 s-1 and autoxidation is thus an important atmospheric pathway for amines. This autoxidation efficiently leads to the formation of hydroperoxy amides, a new type of atmospheric nitrogen-containing compounds, and for TMA, we experimentally confirm this. The conversion of amines to hydroperoxy amides may have important implications for nucleation and growth of atmospheric secondary organic aerosols and atmospheric OH recycling.
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Affiliation(s)
- Kristian H Møller
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark
| | - Torsten Berndt
- Atmospheric Chemistry Department (ACD), Leibniz Institute for Tropospheric Research (TROPOS), Permoserstraße 15, 04318 Leipzig, Germany
| | - Henrik G Kjaergaard
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark
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