CaltechAUTHORS
Published May 5, 2020 | Version Published + Supplemental Material
Journal Article Open

Direct kinetic measurements and theoretical predictions of an isoprene-derived Criegee intermediate

Creators

  • 1. ROR icon Jet Propulsion Lab
  • 2. ROR icon Sandia National Laboratories California
  • 3. ROR icon Argonne National Laboratory
  • 4. ROR icon University of Pennsylvania
  • 5. ROR icon University of Bristol
  • 6. ROR icon Institute of Atomic and Molecular Sciences, Academia Sinica
  • 7. ROR icon National Taiwan University
  • 8. ROR icon California Institute of Technology

Abstract

Isoprene has the highest emission into Earth's atmosphere of any nonmethane hydrocarbon. Atmospheric processing of alkenes, including isoprene, via ozonolysis leads to the formation of zwitterionic reactive intermediates, known as Criegee intermediates (CIs). Direct studies have revealed that reactions involving simple CIs can significantly impact the tropospheric oxidizing capacity, enhance particulate formation, and degrade local air quality. Methyl vinyl ketone oxide (MVK-oxide) is a four-carbon, asymmetric, resonance-stabilized CI, produced with 21 to 23% yield from isoprene ozonolysis, yet its reactivity has not been directly studied. We present direct kinetic measurements of MVK-oxide reactions with key atmospheric species using absorption spectroscopy. Direct UV-Vis absorption spectra from two independent flow cell experiments overlap with the molecular beam UV-Vis-depletion spectra reported recently [M. F. Vansco, B. Marchetti, M. I. Lester, J. Chem. Phys. 149, 44309 (2018)] but suggest different conformer distributions under jet-cooled and thermal conditions. Comparison of the experimental lifetime herein with theory indicates only the syn-conformers are observed; anti-conformers are calculated to be removed much more rapidly via unimolecular decay. We observe experimentally and predict theoretically fast reaction of syn-MVK-oxide with SO₂ and formic acid, similar to smaller alkyl-substituted CIs, and by contrast, slow removal in the presence of water. We determine products through complementary multiplexed photoionization mass spectrometry, observing SO₃ and identifying organic hydroperoxide formation from reaction with SO₂ and formic acid, respectively. The tropospheric implications of these reactions are evaluated using a global chemistry and transport model.

Additional Information

© 2020 National Academy of Sciences. Published under the PNAS license. Contributed by Marsha I. Lester, March 10, 2020 (sent for review October 1, 2019; reviewed by Keith Kuwata and A. R. Ravishankara). PNAS first published April 22, 2020. This material is based upon work supported by the Division of Chemical Sciences, Geosciences and Biosciences, Office of Basic Energy Sciences (BES), US Department of Energy (USDOE). Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the USDOE's National Nuclear Security Administration under contract DE-NA0003525. This paper describes objective technical results and analysis. Any subjective views or opinions that might be expressed in the paper do not necessarily represent the views of the USDOE or the US Government. This material is based in part on research at Argonne supported by the USDOE, Office of Science, BES, Division of Chemical Sciences, Geosciences, and Biosciences under contract DE-AC02-06CH11357. The Advanced Light Source is supported by the Director, Office of Science, BES/USDOE under contract DE- AC02-05CH11231 at Lawrence Berkeley National Laboratory. This research was carried out in part by the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA, supported by the Upper Atmosphere Research and Tropospheric Chemistry program. The contributions of R.L.C. and K.Z. were in part supported by appointments to the NASA Postdoctoral Program at the NASA Jet Propulsion Laboratory, administered by Universities Space Research Association under contract with NASA. This research was also supported by the USDOE-BES under grant DE-FG02-87ER13792 (M.I.L.). P.J.W. thanks the NSF (CHE-1902509). Y.-L.L., Y.-H.L., W.C., and J.J.-M.L. were supported by Academia Sinica and Ministry of Science and Technology, Taiwan (MOST 106-2113-M-001-026-MY3 [J.J.-M.L.]). D.E.S. and M.A.H.K. thank the Natural Environment Research Council (NERC, Grant Code NE/K004905/1), Bristol ChemLabS, and Primary Science Teaching Trust under whose auspices various aspects of this work were funded. We gratefully acknowledge Stanley Sander for useful discussions. The authors also thank Luc Vereecken for his careful reading and thoughtful insights on this manuscript. Data Availability Statement: All data discussed in the paper are available in the main text and SI Appendix. Author contributions: R.L.C., M.F.V., W.C., D.L.O., C.J.P., J.J.-M.L., C.A.T., and M.I.L. designed research; R.L.C., M.F.V., K.A., M.A.H.K., Y.-L.L., F.A.F.W., K.Z., Y.-H.L., D.L.O., C.J.P., D.E.S., L.S., S.J.K., C.A.T., and M.I.L. performed research; N.T. and P.J.W. contributed new reagents/analytic tools; R.L.C., M.F.V., M.A.H.K., Y.-L.L., Y.-H.L., L.S., C.A.T., and M.I.L. analyzed data; and R.L.C., M.F.V., M.A.H.K., J.J.-M.L., S.J.K., C.A.T., and M.I.L. wrote the paper. Reviewers: K.K., Macalester College; and A.R.R., Colorado State University. Competing interest statement: R.L.C., C.A.T., and A. R. Ravishankara are amongst numerous coauthors in the General Discussion associated with the 2017 Faraday Discussion of Atmospheric Chemistry in the Anthropocene [Faraday Discuss. 200, 353–378 (2017)]. This article contains supporting information online at https://www.pnas.org/lookup/suppl/doi:10.1073/pnas.1916711117/-/DCSupplemental.

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Additional details

Identifiers

PMCID
PMC7211945
Eprint ID
102742
DOI
10.1073/pnas.1916711117
Resolver ID
CaltechAUTHORS:20200423-082321588

Related works

Describes
10.1073/pnas.1916711117 (DOI)

Funding

Department of Energy (DOE)
DE-NA0003525
Department of Energy (DOE)
DE-AC02-06CH11357
Department of Energy (DOE)
DE-AC02-05CH11231
NASA/JPL/Caltech
NASA Postdoctoral Program
Department of Energy (DOE)
DE-FG02-87ER13792
NSF
CHE-1902509
Academia Sinica
Ministry of Science and Technology (Taipei)
106-2113-M-001-026-MY3
Natural Environment Research Council (NERC)
NE/K004905/1
Bristol ChemLabS
Primary Science Teaching Trust

Dates

Created
2020-04-23
Created from EPrint's datestamp field
Updated
2021-11-16
Created from EPrint's last_modified field