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Guidry LM, Bardash LA, Yigiter A, Ravi S, Marchetti B, Karsili TNV. The role of solar photolysis in the atmospheric removal of methacrolein oxide and the methacrolein oxide-water van-der Waals complex in pristine environments. Photochem Photobiol 2024. [PMID: 39095969 DOI: 10.1111/php.14007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2024] [Revised: 07/04/2024] [Accepted: 07/15/2024] [Indexed: 08/04/2024]
Abstract
Biogenic hydrocarbons are emitted into the Earth's atmosphere by terrestrial vegetation as by-products of photosynthesis. Isoprene is one such hydrocarbon and is the second most abundant volatile organic compound emitted into the atmosphere (after methane). Reaction with ozone represents an important atmospheric sink for isoprene removal, forming carbonyl oxides (Criegee intermediates) with extended conjugation. In this manuscript, we argue that the extended conjugation of these Criegee intermediates enables electronic excitation of these compounds, on timescales that are competitive with their slow unimolecular decay and bimolecular chemistry. We show that the complexation of methacrolein oxide with water enhances the absorption cross section of the otherwise dark S1 state, potentially revealing a new avenue for forming lower volatility compounds via tropospherically relevant photochemistry.
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Affiliation(s)
- Lily M Guidry
- University of Louisiana at Lafayette, Lafayette, Louisiana, USA
| | | | - Aylin Yigiter
- University of Louisiana at Lafayette, Lafayette, Louisiana, USA
- St. Thomas More Catholic High School, Lafayette, Louisiana, USA
| | - Satyam Ravi
- School of Advanced Science and Languages, VIT Bhopal University, Sehore, Madhya Pradesh, India
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2
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Lee HK, Chantanapongvanij P, Schmidt RR, Stephenson TA. Master Equation Studies of the Unimolecular Decay of Thermalized Methacrolein Oxide: The Impact of Atmospheric Conditions. J Phys Chem A 2023; 127:4492-4502. [PMID: 37163697 DOI: 10.1021/acs.jpca.3c00542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Master equation simulations of the unimolecular reaction dynamics of the Criegee intermediate methacrolein oxide (MACR oxide) have been performed under a variety of temperature and pressure conditions. These simulations provide insight into how the unimolecular kinetics vary across temperatures spanning the range 288-320 K. This work has incorporated a new potential energy surface and includes the anti-to-syn and cis-to-trans conformational dynamics of MACR oxide, as well as the unimolecular reactions to form dioxirane and dioxole species. The competition between the unimolecular reactivity of MACR oxide and previously documented bimolecular reactivity of MACR oxide with water vapor is explored, focusing on how this competition is affected by changes in atmospheric conditions. The impact on the role of MACR oxide as an atmospheric oxidant of SO2 is noted.
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Affiliation(s)
- Hyun Kyung Lee
- Department of Chemistry and Biochemistry, Swarthmore College, 500 College Avenue, Swarthmore, Pennsylvania 19081, United States
| | - Pitchaya Chantanapongvanij
- Department of Chemistry and Biochemistry, Swarthmore College, 500 College Avenue, Swarthmore, Pennsylvania 19081, United States
| | - Rory R Schmidt
- Department of Chemistry and Biochemistry, Swarthmore College, 500 College Avenue, Swarthmore, Pennsylvania 19081, United States
| | - Thomas A Stephenson
- Department of Chemistry and Biochemistry, Swarthmore College, 500 College Avenue, Swarthmore, Pennsylvania 19081, United States
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3
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Yang J, Li Y, Makroni L, Liu F. The photoisomerization mechanism of methacrolein oxide (MACR-OO): the cyclic dioxole formation pathway revealed. Phys Chem Chem Phys 2022; 24:22531-22537. [PMID: 36111632 DOI: 10.1039/d2cp03028d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Methacrolein oxide (MACR-OO), the isopropenyl substituted Criegee intermediate (CI), is one product of isoprene ozonolysis. In this work, we report MACR-OO's photo-isomerization paths with electronic structure calculation at the CASSCF and MS-CASPT2 levels and trajectory surface-hopping (TSH) nonadiabatic dynamics simulation at the CASSCF level. Our calculated results show that the ring-closure is the dominant photo-induced unimolecular isomerization of MACR-OO in the S1 state. In addition, a new photo-induced ring-closure to heterocyclopentane dioxole in syn_syn-MACR-OO is found. The findings of MACR-OO are expected to deepen the understanding of the substituted CIs and their photochemistry.
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Affiliation(s)
- Jiawei Yang
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education, Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an, Shaanxi 710119, People's Republic of China.
| | - Yazhen Li
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education, Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an, Shaanxi 710119, People's Republic of China.
| | - Lily Makroni
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education, Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an, Shaanxi 710119, People's Republic of China.
| | - Fengyi Liu
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education, Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an, Shaanxi 710119, People's Republic of China.
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4
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Formation reaction mechanism and infrared spectra of anti-trans-methacrolein oxide and its associated precursor and adduct radicals. Commun Chem 2022; 5:26. [PMID: 36697653 PMCID: PMC9814089 DOI: 10.1038/s42004-022-00644-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 02/10/2022] [Indexed: 01/28/2023] Open
Abstract
Methacrolein oxide (MACRO) is an important carbonyl oxide produced in ozonolysis of isoprene, the most abundantly-emitted non-methane hydrocarbon in the atmosphere. We employed a step-scan Fourier-transform infrared spectrometer to investigate the source reaction of MACRO in laboratories. Upon UV irradiation of precursor CH2IC(CH3)CHI (1), the CH2C(CH3)CHI radical (2) was detected, confirming the fission of the allylic C‒I bond rather than the vinylic C‒I bond. Upon UV irradiation of (1) and O2 near 21 Torr, anti-trans-MACRO (3a) was observed to have an intense OO-stretching band near 917 cm-1, much greater than those of syn-CH3CHOO and (CH3)2COO, supporting a stronger O‒O bond in MACRO because of resonance stabilization. At increased pressure (86‒346 Torr), both reaction adducts CH2C(CH3)CHIOO (4) and (CHI)C(CH3)CH2OO (5) radicals were observed, indicating that O2 can add to either carbon of the delocalized propenyl radical moiety of (2). The yield of MACRO is significantly smaller than other carbonyl oxides.
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Vereecken L, Novelli A, Kiendler-Scharr A, Wahner A. Unimolecular and water reactions of oxygenated and unsaturated Criegee intermediates under atmospheric conditions. Phys Chem Chem Phys 2022; 24:6428-6443. [DOI: 10.1039/d1cp05877k] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ozonolysis of unsaturated hydrocarbons (VOCs) is one of the main oxidation processes in the atmosphere. The stabilized Criegee intermediates (SCI) formed are highly reactive oxygenated species that potentially influence the...
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6
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Barber VP, Kroll JH. Chemistry of Functionalized Reactive Organic Intermediates in the Earth's Atmosphere: Impact, Challenges, and Progress. J Phys Chem A 2021; 125:10264-10279. [PMID: 34846877 DOI: 10.1021/acs.jpca.1c08221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The gas-phase oxidation of organic compounds is an important chemical process in the Earth's atmosphere. It governs oxidant levels and controls the production of key secondary pollutants, and hence has major implications for air quality and climate. Organic oxidation is largely controlled by the chemistry of a few reactive intermediates, namely, alkyl (R) radicals, alkoxy (RO) radicals, peroxy (RO2) radicals, and carbonyl oxides (R1R2COO), which may undergo a number of unimolecular and bimolecular reactions. Our understanding of these intermediates, and the reaction pathways available to them, is based largely on studies of unfunctionalized intermediates, formed in the first steps of hydrocarbon oxidation. However, it has become increasingly clear that intermediates with functional groups, which are generally formed later in the oxidation process, can exhibit fundamentally different reactivity than unfunctionalized ones. In this Perspective, we explore the unique chemistry available to functionalized organic intermediates in the Earth's atmosphere. After a brief review of the canonical chemistry available to unfunctionalized intermediates, we discuss how the addition of functional groups can introduce new reactions, either by changing the energetics or kinetics of a given reaction or by opening up new chemical pathways. We then provide examples of atmospheric reaction classes that are available only to functionalized intermediates. Some of these, such as unimolecular H-shift reactions of RO2 radicals, have been elucidated only relatively recently, and can have important impacts on atmospheric chemistry (e.g., on radical cycling or organic aerosol formation); it seems likely that other, as-yet undiscovered reactions of (multi)functional intermediates may also exist. We discuss the challenges associated with the study of the chemistry of such intermediates and review novel experimental and theoretical approaches that have recently provided (or hold promise for providing) new insights into their atmospheric chemistry. The continued use and development of such techniques and the close collaboration between experimentalists and theoreticians are necessary for a complete, detailed understanding of the chemistry of functionalized intermediates and their impact on major atmospheric chemical processes.
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Affiliation(s)
- Victoria P Barber
- Departments of Civil and Environmental Engineering and Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Jesse H Kroll
- Departments of Civil and Environmental Engineering and Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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7
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Vansco MF, Zuraski K, Winiberg FAF, Au K, Trongsiriwat N, Walsh PJ, Osborn DL, Percival CJ, Klippenstein SJ, Taatjes CA, Lester MI, Caravan RL. Functionalized Hydroperoxide Formation from the Reaction of Methacrolein-Oxide, an Isoprene-Derived Criegee Intermediate, with Formic Acid: Experiment and Theory. Molecules 2021; 26:3058. [PMID: 34065491 PMCID: PMC8161369 DOI: 10.3390/molecules26103058] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 05/11/2021] [Accepted: 05/13/2021] [Indexed: 11/16/2022] Open
Abstract
Methacrolein oxide (MACR-oxide) is a four-carbon, resonance-stabilized Criegee intermediate produced from isoprene ozonolysis, yet its reactivity is not well understood. This study identifies the functionalized hydroperoxide species, 1-hydroperoxy-2-methylallyl formate (HPMAF), generated from the reaction of MACR-oxide with formic acid using multiplexed photoionization mass spectrometry (MPIMS, 298 K = 25 °C, 10 torr = 13.3 hPa). Electronic structure calculations indicate the reaction proceeds via an energetically favorable 1,4-addition mechanism. The formation of HPMAF is observed by the rapid appearance of a fragment ion at m/z 99, consistent with the proposed mechanism and characteristic loss of HO2 upon photoionization of functional hydroperoxides. The identification of HPMAF is confirmed by comparison of the appearance energy of the fragment ion with theoretical predictions of its photoionization threshold. The results are compared to analogous studies on the reaction of formic acid with methyl vinyl ketone oxide (MVK-oxide), the other four-carbon Criegee intermediate in isoprene ozonolysis.
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Affiliation(s)
- Michael F. Vansco
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, USA; (M.F.V.); (N.T.); (P.J.W.)
- Argonne National Laboratory, Chemical Sciences and Engineering Division, Lemont, IL 60439, USA;
| | - Kristen Zuraski
- NASA Postdoctoral Program Fellow, NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA;
| | - Frank A. F. Winiberg
- NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA; (F.A.F.W.); (C.J.P.)
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Kendrew Au
- Combustion Research Facility, Mailstop 9055, Sandia National Laboratories, Livermore, CA 94551, USA; (K.A.); (D.L.O.)
| | - Nisalak Trongsiriwat
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, USA; (M.F.V.); (N.T.); (P.J.W.)
| | - Patrick J. Walsh
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, USA; (M.F.V.); (N.T.); (P.J.W.)
| | - David L. Osborn
- Combustion Research Facility, Mailstop 9055, Sandia National Laboratories, Livermore, CA 94551, USA; (K.A.); (D.L.O.)
- Department of Chemical Engineering, University of California, Davis, CA 95616, USA
| | - Carl J. Percival
- NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA; (F.A.F.W.); (C.J.P.)
| | - Stephen J. Klippenstein
- Argonne National Laboratory, Chemical Sciences and Engineering Division, Lemont, IL 60439, USA;
| | - Craig A. Taatjes
- Combustion Research Facility, Mailstop 9055, Sandia National Laboratories, Livermore, CA 94551, USA; (K.A.); (D.L.O.)
| | - Marsha I. Lester
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, USA; (M.F.V.); (N.T.); (P.J.W.)
| | - Rebecca L. Caravan
- Argonne National Laboratory, Chemical Sciences and Engineering Division, Lemont, IL 60439, USA;
- NASA Postdoctoral Program Fellow, NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA;
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8
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Surprisingly long lifetime of methacrolein oxide, an isoprene derived Criegee intermediate, under humid conditions. Commun Chem 2021; 4:12. [PMID: 36697547 PMCID: PMC9814537 DOI: 10.1038/s42004-021-00451-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 01/05/2021] [Indexed: 02/07/2023] Open
Abstract
Ozonolysis of isoprene, the most abundant alkene, produces three distinct Criegee intermediates (CIs): CH2OO, methyl vinyl ketone oxide (MVKO) and methacrolein oxide (MACRO). The oxidation of SO2 by CIs is a potential source of H2SO4, an important precursor of aerosols. Here we investigated the UV-visible spectroscopy and reaction kinetics of thermalized MACRO. An extremely fast reaction of anti-MACRO with SO2 has been found, kSO2 = (1.5 ± 0.4) × 10-10 cm3 s-1 (±1σ, σ is the standard deviation of the data) at 298 K (150 - 500 Torr), which is ca. 4 times the value for syn-MVKO. However, the reaction of anti-MACRO with water vapor has been observed to be quite slow with an effective rate coefficient of (9 ± 5) × 10-17 cm3 s-1 (±1σ) at 298 K (300 to 500 Torr), which is smaller than current literature values by 1 or 2 orders of magnitude. Our results indicate that anti-MACRO has an atmospheric lifetime (best estimate ca. 18 ms at 298 K and RH = 70%) much longer than previously thought (ca. 0.3 or 3 ms), resulting in a much higher steady-state concentration. Owing to larger reaction rate coefficient, the impact of anti-MACRO on the oxidation of atmospheric SO2 would be substantial, even more than that of syn-MVKO.
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9
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Mayorov AV, Krisyuk BE, Sokolova N. Kinetics and mechanisms of the first step of ozonolysis of trans-isoprene. COMPUT THEOR CHEM 2020. [DOI: 10.1016/j.comptc.2020.112904] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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10
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Kumar M, Shee J, Rudshteyn B, Reichman DR, Friesner RA, Miller CE, Francisco JS. Multiple Stable Isoprene-Ozone Complexes Reveal Complex Entrance Channel Dynamics in the Isoprene + Ozone Reaction. J Am Chem Soc 2020; 142:10806-10813. [PMID: 32431151 DOI: 10.1021/jacs.0c02360] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Accurately characterizing isoprene ozonolysis continues to challenge atmospheric chemists. The reaction is believed to be a spontaneous, concerted cycloaddition. However, little information is available about the entrance channel and isoprene-ozone complexes thought to define the long-range portion of the reaction coordinate. Our coupled cluster and auxiliary field quantum Monte Carlo calculations predict multiple stable isoprene-ozone van der Waals complexes for trans-isoprene in the gas phase with moderate association energies. These results indicate that long-range dynamics in the isoprene-ozone entrance channel can impact the overall reaction in the troposphere and provide the spectroscopic information necessary to extend the microwave characterization of isoprene ozonolysis to prereactive complexes. At the air-water interface, Born-Oppenheimer molecular dynamics simulations indicate that the cycloaddition reaction between ozone and trans-isoprene follows a stepwise mechanism, which is quite distinct from our proposed gas-phase mechanism and occurs on a femtosecond time scale. The stepwise nature of isoprene ozonolysis on the aqueous surface is more consistent with the DeMore mechanism than with the Criegee mechanism suggested by the gas-phase calculations, suggesting that the reaction media may play an important role in the reaction. Overall, these predictions aim to provide a missing fundamental piece of molecular insight into isoprene ozonolysis, which has broad tropospheric implications due to its critical role as a nighttime source of hydroxyl radicals.
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Affiliation(s)
- Manoj Kumar
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - James Shee
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Benjamin Rudshteyn
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - David R Reichman
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Richard A Friesner
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Charles E Miller
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, United States
| | - Joseph S Francisco
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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Hansen AS, Liu Z, Chen S, Schumer MG, Walsh PJ, Lester MI. Unraveling Conformer-Specific Sources of Hydroxyl Radical Production from an Isoprene-Derived Criegee Intermediate by Deuteration. J Phys Chem A 2020; 124:4929-4938. [PMID: 32449860 DOI: 10.1021/acs.jpca.0c02867] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Ozonolysis of isoprene, the most abundant volatile organic compounds emitted into the Earth's troposphere after methane, yields three distinct Criegee intermediates. Among these, methyl vinyl ketone oxide (MVK-oxide) is predicted to be the major source of atmospheric hydroxyl radicals (OH) from isoprene ozonolysis. Previously, Barber et al. [ J. Am. Chem. Soc., 2018, 140, pp 10866-10880] demonstrated that syn-MVK-oxide conformers undergo unimolecular decay via 1,4-hydrogen (H) transfer from the methyl group to the adjacent terminal oxygen atom, followed by the prompt release of OH radical products. Here, we selectively deuterate the methyl group of MVK-oxide (d3-MVK-oxide) and record its IR action spectrum in the vinyl CH stretch overtone (2νCH) region. The resultant time-dependent appearance of OD radical products, detected by laser-induced fluorescence, demonstrates that a unimolecular decay of d3-MVK-oxide proceeds by an analogous 1,4-deuterium (D) atom transfer mechanism anticipated for syn conformers. The experimental spectral and temporal results are compared with the calculated IR absorption spectrum and unimolecular decay rates predicted by the Rice-Ramsperger-Kassel-Marcus (RRKM) theory for syn-d3-MVK-oxide, as well as the prior study on syn-MVK-oxide. The d3-MVK-oxide IR action spectrum is similar to that for MVK-oxide, yet exhibits notable changes as the overtone and combination transitions involving CD stretch shift to a lower frequency. The unimolecular decay rate for d3-MVK-oxide is predicted to be a factor of 40 times slower than that for MVK-oxide in the 2νCH region. Experimentally, the temporal profile of the OD products reflects the slower unimolecular decay of d3-MVK-oxide compared to that for MVK-oxide to OH products as well as experimental factors. Both experiment and theory demonstrate that quantum mechanical tunneling plays a very important role in the 1,4-H/D-transfer processes at energies in the vicinity of the transition-state barrier. The similarities of the IR action spectra and changes in the unimolecular decay dynamics upon deuteration indicate that syn conformers make the main contribution to the IR action spectra of MVK-oxide and d3-MVK-oxide.
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Affiliation(s)
- Anne S Hansen
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Ziao Liu
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Shuguang Chen
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Mac G Schumer
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Patrick J Walsh
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Marsha I Lester
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
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12
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Vansco MF, Caravan RL, Zuraski K, Winiberg FAF, Au K, Trongsiriwat N, Walsh PJ, Osborn DL, Percival CJ, Khan MAH, Shallcross DE, Taatjes CA, Lester MI. Experimental Evidence of Dioxole Unimolecular Decay Pathway for Isoprene-Derived Criegee Intermediates. J Phys Chem A 2020; 124:3542-3554. [PMID: 32255634 DOI: 10.1021/acs.jpca.0c02138] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Ozonolysis of isoprene, one of the most abundant volatile organic compounds emitted into the Earth's atmosphere, generates two four-carbon unsaturated Criegee intermediates, methyl vinyl ketone oxide (MVK-oxide) and methacrolein oxide (MACR-oxide). The extended conjugation between the vinyl substituent and carbonyl oxide groups of these Criegee intermediates facilitates rapid electrocyclic ring closures that form five-membered cyclic peroxides, known as dioxoles. This study reports the first experimental evidence of this novel decay pathway, which is predicted to be the dominant atmospheric sink for specific conformational forms of MVK-oxide (anti) and MACR-oxide (syn) with the vinyl substituent adjacent to the terminal O atom. The resulting dioxoles are predicted to undergo rapid unimolecular decay to oxygenated hydrocarbon radical products, including acetyl, vinoxy, formyl, and 2-methylvinoxy radicals. In the presence of O2, these radicals rapidly react to form peroxy radicals (ROO), which quickly decay via carbon-centered radical intermediates (QOOH) to stable carbonyl products that were identified in this work. The carbonyl products were detected under thermal conditions (298 K, 10 Torr He) using multiplexed photoionization mass spectrometry (MPIMS). The main products (and associated relative abundances) originating from unimolecular decay of anti-MVK-oxide and subsequent reaction with O2 are formaldehyde (88 ± 5%), ketene (9 ± 1%), and glyoxal (3 ± 1%). Those identified from the unimolecular decay of syn-MACR-oxide and subsequent reaction with O2 are acetaldehyde (37 ± 7%), vinyl alcohol (9 ± 1%), methylketene (2 ± 1%), and acrolein (52 ± 5%). In addition to the stable carbonyl products, the secondary peroxy chemistry also generates OH or HO2 radical coproducts.
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Affiliation(s)
- Michael F Vansco
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Rebecca L Caravan
- NASA Postdoctoral Program, NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, United States.,Combustion Research Facility, Sandia National Laboratories, Mailstop 9055, Livermore, California 94551, United States.,Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Kristen Zuraski
- NASA Postdoctoral Program, NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, United States
| | - Frank A F Winiberg
- NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, United States.,California Institute of Technology, Pasadena, California 91125, United States
| | - Kendrew Au
- Combustion Research Facility, Sandia National Laboratories, Mailstop 9055, Livermore, California 94551, United States
| | - Nisalak Trongsiriwat
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Patrick J Walsh
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - David L Osborn
- Combustion Research Facility, Sandia National Laboratories, Mailstop 9055, Livermore, California 94551, United States
| | - Carl J Percival
- NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, United States.,California Institute of Technology, Pasadena, California 91125, United States
| | - M Anwar H Khan
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - Dudley E Shallcross
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - Craig A Taatjes
- Combustion Research Facility, Sandia National Laboratories, Mailstop 9055, Livermore, California 94551, United States
| | - Marsha I Lester
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
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13
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Barber VP, Hansen AS, Georgievskii Y, Klippenstein SJ, Lester MI. Experimental and theoretical studies of the doubly substituted methyl-ethyl Criegee intermediate: Infrared action spectroscopy and unimolecular decay to OH radical products. J Chem Phys 2020; 152:094301. [PMID: 33480748 DOI: 10.1063/5.0002422] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The infrared (IR) action spectrum of the doubly substituted methyl-ethyl Criegee intermediate (MECI) is observed in the CH stretch overtone region with detection of OH products. The MECI exhibits four conformers, all of which undergo unimolecular decay via a 1,4 H-atom transfer mechanism, followed by the rapid release of OH products. Conformers with different orientations of the carbonyl oxide group with respect to the methyl and ethyl substituents (i.e., anti and syn) decay via distinct transition state barriers (16.1 kcal mol-1 and 15.4 kcal mol-1, respectively). The observed IR action spectrum is in good agreement with the predicted anharmonic IR absorption spectrum, but exhibits significant congestion, which is attributed to couplings between spectroscopic bright states and nearby dark states. Energy-dependent OH appearance rates are measured upon IR excitation of the strongest features in the IR action spectrum and are found to be on the order of 106-107 s-1. The experimental rates are in good agreement with computed Rice-Ramsperger-Kassel-Marcus rates for the unimolecular decay of MECI at these energies, which incorporate quantum mechanical tunneling and sophisticated hindered rotor treatments, as well as high-level theoretical calculations of the TS barrier heights, rovibrational properties, and torsional barriers associated with the MECI conformers. Master equation modeling is used to predict thermal rates for the unimolecular decay of anti- and syn-MECI of 473 s-1 and 660 s-1, respectively. Comparison with other previously studied Criegee intermediate systems provides insights into substituent effects on unimolecular decay under both energy-dependent and thermal conditions.
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Affiliation(s)
- Victoria P Barber
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
| | - Anne S Hansen
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
| | - Yuri Georgievskii
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Stephen J Klippenstein
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Marsha I Lester
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
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14
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15
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Stephenson TA, Lester MI. Unimolecular decay dynamics of Criegee intermediates: Energy-resolved rates, thermal rates, and their atmospheric impact. INT REV PHYS CHEM 2019. [DOI: 10.1080/0144235x.2020.1688530] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Thomas A. Stephenson
- Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore, PA, USA
| | - Marsha I. Lester
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, USA
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16
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Vansco MF, Marchetti B, Trongsiriwat N, Bhagde T, Wang G, Walsh PJ, Klippenstein SJ, Lester MI. Synthesis, Electronic Spectroscopy, and Photochemistry of Methacrolein Oxide: A Four-Carbon Unsaturated Criegee Intermediate from Isoprene Ozonolysis. J Am Chem Soc 2019; 141:15058-15069. [PMID: 31446755 DOI: 10.1021/jacs.9b05193] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Ozonolysis of isoprene, one of the most abundant volatile organic compounds in the earth's atmosphere, generates the four-carbon unsaturated methacrolein oxide (MACR-oxide) Criegee intermediate. The first laboratory synthesis and direct detection of MACR-oxide is achieved through reaction of photolytically generated, resonance-stabilized iodoalkene radicals with oxygen. MACR-oxide is characterized on its first π* ← π electronic transition using a ground-state depletion method. MACR-oxide exhibits a broad UV-visible spectrum peaked at 380 nm with weak oscillatory structure at long wavelengths ascribed to vibrational resonances. Complementary theory predicts two strong π* ← π transitions arising from extended conjugation across MACR-oxide with overlapping contributions from its four conformers. Electronic promotion to the 11ππ* state agrees well with experiment, and results in nonadiabatic coupling and prompt release of O 1D products observed as anisotropic velocity-map images. This UV-visible detection scheme will enable study of its unimolecular and bimolecular reactions under thermal conditions of relevance to the atmosphere.
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Affiliation(s)
- Michael F Vansco
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Barbara Marchetti
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Nisalak Trongsiriwat
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Trisha Bhagde
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Guanghan Wang
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Patrick J Walsh
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Stephen J Klippenstein
- Chemical Sciences and Engineering Division , Argonne National Laboratory , Lemont , Illinois 60439 , United States
| | - Marsha I Lester
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104-6323 , United States
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17
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Almatarneh MH, Elayan IA, Abu‐Saleh AAA, Altarawneh M, Ariya PA. The gas‐phase ozonolysis reaction of methylbutenol: A mechanistic study. INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY 2019; 119:e25888. [DOI: 10.1002/qua.25888] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Affiliation(s)
- Mansour H. Almatarneh
- Department of ChemistryUniversity of Jordan Amman Jordan
- Department of ChemistryMemorial University St. John's NL Canada
| | | | | | - Mohammednoor Altarawneh
- School of Engineering and Information TechnologyMurdoch University Perth Australia
- Chemical Engineering DepartmentAl‐Hussein Bin Talal University Ma'an Jordan
| | - Parisa A. Ariya
- Department of ChemistryMcGill University Montreal Canada
- Department of Atmospheric and Oceanic SciencesMcGill University Montreal Canada
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18
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Rapid unimolecular reaction of stabilized Criegee intermediates and implications for atmospheric chemistry. Nat Commun 2019; 10:2003. [PMID: 31043594 PMCID: PMC6494847 DOI: 10.1038/s41467-019-09948-7] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 04/03/2019] [Indexed: 11/10/2022] Open
Abstract
Elucidating atmospheric oxidation mechanisms is necessary for estimating the lifetimes of atmospheric species and understanding secondary organic aerosol formation and atmospheric oxidation capacity. We report an unexpectedly fast mechanistic pathway for the unimolecular reactions of large stabilized Criegee intermediates, which involves the formation of bicyclic structures from large Criegee intermediates containing an aldehyde group. The barrier heights of the mechanistic pathways are unexpectedly low – about 2–3 kcal/mol – and are at least 10 kcal/mol lower than those of hydrogen shift processes in large syn Criegee intermediates; and the calculated rate constants show that the mechanistic pathways are 105-109 times faster than those of the corresponding hydrogen shift processes. The present findings indicate that analogous low-energy pathways can now also be expected in other large Criegee intermediates and that oxidative capacity of some Criegee intermediates is smaller than would be predicted by existing models. Criegee intermediates have received much attention in atmospheric chemistry because of their importance in ozonolysis mechanisms. Here, using quantum mechanical kinetics, the authors reveal an unexpectedly fast mechanistic pathway for unimolecular reactions of large stabilized Criegee intermediates.
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19
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Porterfield JP, Westerfield JH, Satterthwaite L, Patterson D, Changala PB, Baraban JH, McCarthy MC. Rotational Characterization of the Elusive gauche-Isoprene. J Phys Chem Lett 2019; 10:1981-1985. [PMID: 30897904 DOI: 10.1021/acs.jpclett.9b00411] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Isoprene (2-methyl-1,3-butadiene) is highly abundant in the atmosphere, second only to methane in hydrocarbon emissions. In contrast to the most stable trans rotamer, structural characterization of gauche-isoprene has proven challenging: it is weakly polar, present at the level of only a few percent at room temperature, and structurally complex due to both torsional and methyl tunneling motions. gauche-Isoprene has been observed by two distinct but complementary experimental approaches: chirped-pulse Fourier transform microwave (CP-FTMW) spectroscopy coupled with cryogenic buffer gas cooling, and cavity-enhanced FTMW spectroscopy with a pulsed discharge source. Thermal enhancement of the gauche population (from 1.7% to 10.3%) was observed in the cryogenic buffer gas cell when the sample was preheated from 300 to 450 K, demonstrating that high-energy rotamers can be efficiently isolated under our experimental conditions. Rotational parameters for the inversion states (0+/0-) have been determined for the first time, aided by calculations at increasing levels of theoretical sophistication. From this combined analysis, the inversion splitting Δ E and the Fbc Coriolis coupling constant between the two inversion states have been derived.
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Affiliation(s)
- Jessica P Porterfield
- Harvard-Smithsonian Center for Astrophysics , Cambridge , Massachusetts 02138 , United States
| | - J H Westerfield
- Department of Chemistry , New College of Florida , Sarasota , Florida 34243 , United States
| | - Lincoln Satterthwaite
- Department of Physics , University of California , Santa Barbara , California 93106 , United States
| | - David Patterson
- Department of Physics , University of California , Santa Barbara , California 93106 , United States
| | - P Bryan Changala
- Department of Physics , University of Colorado , Boulder , Colorado 80302 , United States
| | - Joshua H Baraban
- Department of Chemistry , Ben-Gurion University of the Negev , Beersheva 84105 , Israel
| | - Michael C McCarthy
- Harvard-Smithsonian Center for Astrophysics , Cambridge , Massachusetts 02138 , United States
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20
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Vansco MF, Marchetti B, Lester MI. Electronic spectroscopy of methyl vinyl ketone oxide: A four-carbon unsaturated Criegee intermediate from isoprene ozonolysis. J Chem Phys 2019; 149:244309. [PMID: 30599734 DOI: 10.1063/1.5064716] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Ozonolysis of isoprene, one of the most abundant volatile organic compounds in the atmosphere, proceeds through methyl vinyl ketone oxide (MVK-oxide), methacrolein oxide, and formaldehyde oxide (CH2OO) Criegee intermediates. The present study focuses on MVK-oxide, a four-carbon unsaturated carbonyl oxide intermediate, using vacuum ultraviolet photoionization at 118 nm and UV-visible induced depletion of the m/z = 86 mass channel to characterize its first π* ← π electronic transition. The electronic spectrum is broad and unstructured with its peak at 388 nm (3.2 eV). The MVK-oxide spectrum is shifted to a significantly longer wavelength than CH2OO and alkyl-substituted Criegee intermediates studied previously due to extended conjugation across the vinyl and carbonyl oxide groups. Electronic excitation results in rapid dissociation at λ ≤ 430 nm to methyl vinyl ketone and O 1D products, the latter detected by 2 + 1 resonance enhanced multiphoton ionization using velocity map imaging. Complementary electronic structure calculations (CASPT2(12,10)/AVDZ) predict two π* ← π transitions with significant oscillator strength for each of the four conformers of MVK-oxide with vertical excitation energies (and corresponding wavelengths) in the 3.1-3.6 eV (350-400 nm) and 4.5-5.5 eV (220-280 nm) regions. The computed electronic absorption profile of MVK-oxide, based on a Wigner distribution of ground state configurations and summed over the four conformers, is predicted to peak at 397 nm. UV-visible spectroscopy on the first π* ← π transition is shown by a combination of experiment and theory to provide a sensitive method for detection of the MVK-oxide Criegee intermediate that will enable further studies of its photochemistry and unimolecular and bimolecular reaction dynamics.
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Affiliation(s)
- Michael F Vansco
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
| | - Barbara Marchetti
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
| | - Marsha I Lester
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
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21
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Barber VP, Pandit S, Green AM, Trongsiriwat N, Walsh PJ, Klippenstein SJ, Lester MI. Four-Carbon Criegee Intermediate from Isoprene Ozonolysis: Methyl Vinyl Ketone Oxide Synthesis, Infrared Spectrum, and OH Production. J Am Chem Soc 2018; 140:10866-10880. [PMID: 30074392 DOI: 10.1021/jacs.8b06010] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The reaction of ozone with isoprene, one of the most abundant volatile organic compounds in the atmosphere, produces three distinct carbonyl oxide species (RR'COO) known as Criegee intermediates: formaldehyde oxide (CH2OO), methyl vinyl ketone oxide (MVK-OO), and methacrolein oxide (MACR-OO). The nature of the substituents (R,R' = H, CH3, CH═CH2) and conformations of the Criegee intermediates control their subsequent chemistry in the atmosphere. In particular, unimolecular decay of MVK-OO is predicted to be the major source of hydroxyl radicals (OH) in isoprene ozonolysis. This study reports the initial laboratory synthesis and direct detection of MVK-OO through reaction of a photolytically generated, resonance-stabilized monoiodoalkene radical with O2. MVK-OO is characterized utilizing infrared (IR) action spectroscopy, in which IR activation of MVK-OO with two quanta of CH stretch at ca. 6000 cm-1 is coupled with ultraviolet detection of the resultant OH products. MVK-OO is identified by comparison of the experimentally observed IR spectral features with theoretically predicted IR absorption spectra. For syn-MVK-OO, the rate of appearance of OH products agrees with the unimolecular decay rate predicted using statistical theory with tunneling. This validates the hydrogen atom transfer mechanism and computed transition-state barrier (18.0 kcal mol-1) leading to OH products. Theoretical calculations reveal an additional roaming pathway between the separating radical fragments, which results in other products. Master equation modeling yields a thermal unimolecular decay rate for syn-MVK-OO of 33 s-1 (298 K, 1 atm). For anti-MVK-OO, theoretical exploration of several unimolecular decay pathways predicts that isomerization to dioxole is the most likely initial step to products.
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Affiliation(s)
- Victoria P Barber
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Shubhrangshu Pandit
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Amy M Green
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Nisalak Trongsiriwat
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Patrick J Walsh
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Stephen J Klippenstein
- Chemical Sciences and Engineering Division , Argonne National Laboratory , Argonne , Illinois 60439 , United States
| | - Marsha I Lester
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104-6323 , United States
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22
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Porterfield JP, Eibenberger S, Patterson D, McCarthy MC. The ozonolysis of isoprene in a cryogenic buffer gas cell by high resolution microwave spectroscopy. Phys Chem Chem Phys 2018; 20:16828-16834. [PMID: 29892741 DOI: 10.1039/c8cp02055h] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have developed a method to quantify reaction product ratios using high resolution microwave spectroscopy in a cryogenic buffer gas cell. We demonstrate the power of this method with the study of the ozonolysis of isoprene, CH2[double bond, length as m-dash]C(CH3)-CH[double bond, length as m-dash]CH2, the most abundant, non-methane hydrocarbon emitted into the atmosphere by vegetation. Isoprene is an asymmetric diene, and reacts with O3 at the 1,2 position to produce methyl vinyl ketone (MVK), formaldehyde, and a pair of carbonyl oxides: [CH3CO-CH[double bond, length as m-dash]CH2 + CH2[double bond, length as m-dash]OO] + [CH2[double bond, length as m-dash]O + CH3COO-CH[double bond, length as m-dash]CH2]. Alternatively, O3 could attack at the 3,4 position to produce methacrolein (MACR), formaldehyde, and two carbonyl oxides [CH2[double bond, length as m-dash]C(CH3)-CHO + CH2[double bond, length as m-dash]OO] + [CH2[double bond, length as m-dash]O + CH2[double bond, length as m-dash]C(CH3)-CHOO]. Purified O3 and isoprene were mixed for approximately 10 seconds under dilute (1.5-4% in argon) continuous flow conditions in an alumina tube held at 298 K and 5 Torr. Products exiting the tube were rapidly slowed and cooled within the buffer gas cell by collisions with cryogenic (4-7 K) He. High resolution chirped pulse microwave detection between 12 and 26 GHz was used to achieve highly sensitive (ppb scale), isomer-specific product quantification. We observed a ratio of MACR to MVK of 2.1 ± 0.4 under 1 : 1 ozone to isoprene conditions and 2.1 ± 0.2 under 2 : 1 ozone to isoprene conditions, a finding which is consistent with previous experimental results. Additionally, we discuss relative quantities of formic acid (HCOOH), an isomer of CH2[double bond, length as m-dash]OO, and formaldehyde (CH2[double bond, length as m-dash]O) under varying experimental conditions, and characterize the spectroscopic parameters of the singly-substituted 13C trans-isoprene and 13C anti-periplanar-methacrolein species. This work has the potential to be extended towards a complete branching ratio analysis, as well towards the ability to isolate, identify, and quantify new reactive intermediates in the ozonolysis of alkenes.
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Affiliation(s)
- Jessica P Porterfield
- Harvard-Smithsonian Center for Astrophysics, Harvard University, Cambridge, MA 02138, USA.
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23
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Wennberg PO, Bates KH, Crounse JD, Dodson LG, McVay RC, Mertens LA, Nguyen TB, Praske E, Schwantes RH, Smarte MD, St Clair JM, Teng AP, Zhang X, Seinfeld JH. Gas-Phase Reactions of Isoprene and Its Major Oxidation Products. Chem Rev 2018. [PMID: 29522327 DOI: 10.1021/acs.chemrev.7b00439] [Citation(s) in RCA: 145] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Isoprene carries approximately half of the flux of non-methane volatile organic carbon emitted to the atmosphere by the biosphere. Accurate representation of its oxidation rate and products is essential for quantifying its influence on the abundance of the hydroxyl radical (OH), nitrogen oxide free radicals (NO x), ozone (O3), and, via the formation of highly oxygenated compounds, aerosol. We present a review of recent laboratory and theoretical studies of the oxidation pathways of isoprene initiated by addition of OH, O3, the nitrate radical (NO3), and the chlorine atom. From this review, a recommendation for a nearly complete gas-phase oxidation mechanism of isoprene and its major products is developed. The mechanism is compiled with the aims of providing an accurate representation of the flow of carbon while allowing quantification of the impact of isoprene emissions on HO x and NO x free radical concentrations and of the yields of products known to be involved in condensed-phase processes. Finally, a simplified (reduced) mechanism is developed for use in chemical transport models that retains the essential chemistry required to accurately simulate isoprene oxidation under conditions where it occurs in the atmosphere-above forested regions remote from large NO x emissions.
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24
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Vereecken L, Novelli A, Taraborrelli D. Unimolecular decay strongly limits the atmospheric impact of Criegee intermediates. Phys Chem Chem Phys 2018; 19:31599-31612. [PMID: 29182168 DOI: 10.1039/c7cp05541b] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Stabilized Criegee intermediates (SCI) are reactive oxygenated species formed in the ozonolysis of hydrocarbons. Their chemistry could influence the oxidative capacity of the atmosphere by affecting the HOx and NOx cycles, or by the formation of low-volatility oxygenates enhancing atmospheric aerosols known to have an important impact on climate. The concentration of SCI in the atmosphere has hitherto not been determined reliably, and very little is known about their speciation. Here we show that the concentration of biogenic SCI is strongly limited by their unimolecular decay, based on extensive theory-based structure-activity relationships (SARs) for the reaction rates for decomposition. Reaction with water vapor, H2O and (H2O)2 molecules, is the second most important loss process; SARs are also proposed for these reactions. For SCI derived from the most common biogenic VOCs, we find that unimolecular decay is responsible for just over half of the loss, with reaction with water vapor the main remaining loss process. Reactions with SO2, NO2, or acids have negligible impact on the atmospheric SCI concentration. The ambient SCI concentrations are further characterized by analysis of field data with speciated hydrocarbon information, and by implementation of the chemistry in a global chemistry model. The results show a highly complex SCI speciation, with an atmospheric peak SCI concentrations below 1 × 105 molecule cm-3, and annual average SCI concentrations less than 7 × 103 molecule cm-3. We find that SCI have only a negligible impact on the global gas phase H2SO4 formation or removal of oxygenates, though some contribution around the equatorial belt, and in select regions, cannot be excluded.
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Affiliation(s)
- L Vereecken
- Forschungszentrum Jülich GmbH, Institute for Energy and Climate, IEK-8 Troposphere, 52428 Jülich, Germany.
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25
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Li M, Liu Y, Wang L. Gas-phase ozonolysis of furans, methylfurans, and dimethylfurans in the atmosphere. Phys Chem Chem Phys 2018; 20:24735-24743. [DOI: 10.1039/c8cp04947e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ozonolysis of methylfurans contributes significantly to their atmospheric degradation.
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Affiliation(s)
- Mengke Li
- School of Chemistry & Chemical Engineering
- South China University of Technology
- Guangzhou 510640
- China
| | - Yuhong Liu
- School of Chemistry & Chemical Engineering
- South China University of Technology
- Guangzhou 510640
- China
| | - Liming Wang
- School of Chemistry & Chemical Engineering
- South China University of Technology
- Guangzhou 510640
- China
- Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control
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26
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Sakamoto Y, Yajima R, Inomata S, Hirokawa J. Water vapour effects on secondary organic aerosol formation in isoprene ozonolysis. Phys Chem Chem Phys 2017; 19:3165-3175. [DOI: 10.1039/c6cp04521a] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A portion of stabilized Criegee intermediates formed in isoprene ozonolysis can be involved in SOA formation even under humid conditions.
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Affiliation(s)
- Yosuke Sakamoto
- Graduate School of Global Environmental Studies
- Kyoto University
- Kyoto
- Japan
- Graduate School of Human and Environmental Studies
| | - Ryoji Yajima
- Graduate School of Environmental Science
- Hokkaido University
- Sapporo
- Japan
| | - Satoshi Inomata
- Center for Global Environmental Research
- National Institute for Environmental Studies
- Tsukuba
- Japan
| | - Jun Hirokawa
- Faculty of Environmental Earth Science
- Hokkaido University
- Sapporo
- Japan
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27
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Yin C, Takahashi K. How does substitution affect the unimolecular reaction rates of Criegee intermediates? Phys Chem Chem Phys 2017; 19:12075-12084. [DOI: 10.1039/c7cp01091e] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Unimolecular reaction rates of Criegee intermediates show substitution effect.
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Affiliation(s)
- Cangtao Yin
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei
- Taiwan
| | - Kaito Takahashi
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei
- Taiwan
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28
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Nguyen TB, Tyndall GS, Crounse JD, Teng AP, Bates KH, Schwantes RH, Coggon MM, Zhang L, Feiner P, Milller DO, Skog KM, Rivera-Rios JC, Dorris M, Olson KF, Koss A, Wild RJ, Brown SS, Goldstein AH, de Gouw JA, Brune WH, Keutsch FN, Seinfeld JH, Wennberg PO. Atmospheric fates of Criegee intermediates in the ozonolysis of isoprene. Phys Chem Chem Phys 2016; 18:10241-54. [PMID: 27021601 DOI: 10.1039/c6cp00053c] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We use a large laboratory, modeling, and field dataset to investigate the isoprene + O3 reaction, with the goal of better understanding the fates of the C1 and C4 Criegee intermediates in the atmosphere. Although ozonolysis can produce several distinct Criegee intermediates, the C1 stabilized Criegee (CH2OO, 61 ± 9%) is the only one observed to react bimolecularly. We suggest that the C4 Criegees have a low stabilization fraction and propose pathways for their decomposition. Both prompt and non-prompt reactions are important in the production of OH (28% ± 5%) and formaldehyde (81% ± 16%). The yields of unimolecular products (OH, formaldehyde, methacrolein (42 ± 6%) and methyl vinyl ketone (18 ± 6%)) are fairly insensitive to water, i.e., changes in yields in response to water vapor (≤4% absolute) are within the error of the analysis. We propose a comprehensive reaction mechanism that can be incorporated into atmospheric models, which reproduces laboratory data over a wide range of relative humidities. The mechanism proposes that CH2OO + H2O (k(H2O)∼ 1 × 10(-15) cm(3) molec(-1) s(-1)) yields 73% hydroxymethyl hydroperoxide (HMHP), 6% formaldehyde + H2O2, and 21% formic acid + H2O; and CH2OO + (H2O)2 (k(H2O)2∼ 1 × 10(-12) cm(3) molec(-1) s(-1)) yields 40% HMHP, 6% formaldehyde + H2O2, and 54% formic acid + H2O. Competitive rate determinations (kSO2/k(H2O)n=1,2∼ 2.2 (±0.3) × 10(4)) and field observations suggest that water vapor is a sink for greater than 98% of CH2OO in a Southeastern US forest, even during pollution episodes ([SO2] ∼ 10 ppb). The importance of the CH2OO + (H2O)n reaction is demonstrated by high HMHP mixing ratios observed over the forest canopy. We find that CH2OO does not substantially affect the lifetime of SO2 or HCOOH in the Southeast US, e.g., CH2OO + SO2 reaction is a minor contribution (<6%) to sulfate formation. Extrapolating, these results imply that sulfate production by stabilized Criegees is likely unimportant in regions dominated by the reactivity of ozone with isoprene. In contrast, hydroperoxide, organic acid, and formaldehyde formation from isoprene ozonolysis in those areas may be significant.
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Affiliation(s)
- Tran B Nguyen
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA.
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29
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Oliveira RCDM, Bauerfeldt GF. Ozonolysis reactions of monoterpenes: a variational transition state investigation. J Phys Chem A 2015; 119:2802-12. [PMID: 25734376 DOI: 10.1021/jp5129222] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The O3-initiated oxidation reactions of α-pinene ([1S,5S]-2,6,6-trimethylbicyclo[3.1.1]hept-2-ene), β-pinene ([1R,5R]-6,6-dimethyl-2-methylenebicyclo[3.1.1]heptane), camphene ([1R,4S]-2,2-dimethyl-3-methylenebicyclo[2.2.1]heptane) and sabinene ([1R,5R]-4-methylene-1-(1-methylethyl)bicycle[3.1.0]hexane), four monoterpenes typically emitted into the atmosphere, were studied at the B3LYP/6-31+G(2d,2p) level of theory. The rate coefficients were calculated on the basis of the variational transition state theory for two kinetic models, in order to investigate the reaction mechanism: first assuming a direct bimolecular reaction and the second, assuming the formation of a prebarrier-complex, which further reacts forming the corresponding molozonide. The barrier heights leading to the formation of exo-conformers of the molozonides of α-pinene and camphene are lower than the barrier heights for the formation of the endo-conformers of these molozonides, whereas the inverse trend is observed for β-pinene and sabinene. The canonical variational rate coefficients are found in reasonable agreement with the experimental data, especially when the prebarrier complexes are considered. Microcanonical variational rate coefficients are also calculated, as a final validation test, being found in an expected agreement with the canonical rate coefficients. The best predictions for the rate coefficients at 298 K, based on the microcanonical variational method, for α-pinene, β-pinene, camphene, and sabine are (in units cm(3) molecule(-1) s(-1)): 6.92 × 10(-17), 1.06 × 10(-17), 4.61 × 10(-19), and 4.81 × 10(-17), respectively. Our results suggest that the prebarrier complex is an important specie in the ozone addition mechanism and should be taken into account for the proper description of the overall kinetics.
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Affiliation(s)
- R C de M Oliveira
- Departamento de Química, Universidade Federal Rural do Rio de Janeiro, Rodovia BR465, Km 7, Seropédica, RJ 23890-000, Brazil
| | - G F Bauerfeldt
- Departamento de Química, Universidade Federal Rural do Rio de Janeiro, Rodovia BR465, Km 7, Seropédica, RJ 23890-000, Brazil
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30
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Oliveira RCDM, Bauerfeldt GF. Thermochemical analysis and kinetics aspects for a chemical model for camphene ozonolysis. J Chem Phys 2012; 137:134306. [DOI: 10.1063/1.4757150] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
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Anglada JM, González J, Torrent-Sucarrat M. Effects of the substituents on the reactivity of carbonyl oxides. A theoretical study on the reaction of substituted carbonyl oxides with water. Phys Chem Chem Phys 2011; 13:13034-45. [PMID: 21687896 DOI: 10.1039/c1cp20872a] [Citation(s) in RCA: 158] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reactions between fifteen carbonyl oxides and water have been investigated with the aim of contributing to a better understanding of the effects of the substituents in the reactivity of carbonyl oxides. We have employed density functional theory and large scale ab initio methods (CCSD(T), CASSCF, and CASPT2), combined with transition state theory, to investigate the addition of water to carbonyl oxide and, for those carbonyl oxides having a methyl substituent in syn, the hydrogen transfer from the methyl group to the terminal oxygen of carbonyl oxide. In this case, the water acts as a catalyst and this reaction can contribute to the atmospheric formation of a hydroxyl radical. Carbonyl oxides with electron withdrawing substituents and zwitterionic character have low energy barriers and react fast, whereas carbonyl oxides with electron releasing substituents have high energy barriers and react slowly. The position of the substituents plays also an important role and carbonyl oxides having a hydrogen atom substituent in syn react faster than carbonyl oxides having a hydrogen atom substituent in anti. The differences in the reactivity of different substituted carbonyl oxides raise up to ten orders of magnitude and the branching ratios for the two different reactions investigated are also reported.
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Affiliation(s)
- J M Anglada
- Departament de Química Biològica i Modelització Molecular (IQAC-CSIC), c/Jordi Girona 18, E-08034 Barcelona, Spain.
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Zhang X, Li X, Qin W. Investigation of the catalytic activity for ozonation on the surface of NiO nanoparticles. Chem Phys Lett 2009. [DOI: 10.1016/j.cplett.2009.08.029] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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