Rebecca L. Caravan

• Chemist (2025-present), Argonne National Laboratory.
• Assistant Chemist (2020-2025), Argonne National Laboratory.
• NASA NPP postdoctoral fellow (2019) with Dr. Carl J. Percival, NASA Jet Propulsion Laboratory, California Institute of Technology.
• Postdoc (2015-2019) with Dr. Craig A. Taatjes, Sandia National Laboratories.

Education

• Ph.D. (2015) Chemistry, University of Leeds, United Kingdom.
• B.Sc. (2011) Chemistry, University of Bristol, United Kingdom.

Research

We study the reaction kinetics and mechanisms of gas-phase reactive intermediates to understand their roles in driving change in complex chemical environments, such as Earth’s lower atmosphere. Recently, our work has focused on interrogating the role of oxygenated zwitterions and radicals in molecular weight growth processes that lead to gas-particle transformations in Earth’s troposphere. Through a combination of experimental work and theory, we interrogate the fundamental chemical physics that drives and influences these reactions. 

Our experimental techniques include tabletop broadband UV-Vis transient absorption spectroscopy at Argonne, and multiplexed photoionization mass spectrometry experiments at the Advanced Light Source at Lawrence Berkeley National Laboratory, in collaboration with research teams from Sandia National Laboratories, NASA Jet Propulsion Laboratory, University of Pennsylvania, and Coastal Carolina University. We also collaborate with atmospheric chemists, including modellers at the University of Bristol, and field scientists at the University of Manchester to address the wider impacts of individual reactions, and reaction sequences, that we have studied in the lab. 

News 

• RLC awarded inaugural Wing Tsang Early Career Award at the 13^th International Conference on Chemical Kinetics. Press release here.
• Our paper on Criegee intermediate oligomerization reactions is published in Nature Geoscience. Press release here.
• RLC selected for PSE Early Investigator Named Award.
• Our paper demonstrating the dramatic conformer dependent reactivity of CH₃CHOO with dimethyl amine is featured on the cover of Journal of Physical Chemistry A, and as a Department of Energy, Basic Energy Sciences highlight.
• Our paper on the reaction of OH with CH₃OO is published in Nature Communications. Press release here. 

Select publications

Observational evidence for Criegee intermediate oligomerization reactions relevant to aerosol formation in the troposphere, R. L. Caravan, T. J. Bannan, F. A. F. Winiberg, M. A. H. Khan, A. C. Rousso, A. W. Jasper, S. D. Worrall, A. Bacak, P. Artaxo, J. Brito, M. Priestley, J. D. Allan, H. Coe, Y. Ju, D. L. Osborn, N. Hansen, S. J. Klippenstein, D. E. Shallcross, C. A. Taatjes & C. J. Percival,  Nature Geoscience (2024) Link

Bimolecular reaction of methyl-ethyl-substituted Criegee intermediate with SO₂ ​‚M . Zou, T. Liu, M. F. Vansco, C. A. Sojdak, C. R. Markus, R. Almeida, K. Au, L. Sheps, D. L. Osborn, F. A. F. Winiberg, C. J. Percival, C. A. Taatjes, S. J. Klippenstein, M. I. Lester & R. L. Caravan, Journal of Physical Chemistry A (2023) Link

OH Roaming and Beyond in the Unimolecular Decay of the Methyl-Ethyl-Substituted Criegee Intermediate: Observations and Predictions, T. Liu, S. N. Elliott, M. Zou, M. F. Vansco, C. A. Sojdak, C. R. Markus, R. Almeida, K. Au, L. Sheps, D. L. Osborn, F. A. F. Winiberg, C. J. Percival, C. A. Taatjes, R. L. Caravan, S. J. Klippenstein & M. I. Lester, Journal of the American Chemical Society (2023) Link

Formation of Organic Acids and Carbonyl Compounds in n-Butane Oxidation via γ-Ketohydroperoxide Decomposition,D. M. Popolan-Vaida, A. J. Eskola, B. Rotavera, J. F. Lockyear, Z. Wang, S. M. Sarathy, R. L. Caravan, J. Zádor, L. Sheps, A. Lucassen, K. Moshammer, P. Dagaut, D. L. Osborn, N. Hansen, S. R. Leone & C. A. Taatjes, Angewandte Chemie International Edition (2022) Link

Open questions on the reactivity of Criegee intermediates, R. L. Caravan, M. F. Vansco, M. I. Lester,  Communications Chemistry (2021) Link

Direct kinetic measurements and theoretical predictions of an isoprene-derived Criegee intermediate, R. L. Caravan, M. F. Vansco, K. Au, M. A. H. Khan, Y.-L. Li, F. A. F. Winiberg, K. Zuraski, Y.-H. Lin, W. Chao, N. Trongsiriwat, P. J. Walsh, D. L. Osborn, C. J. Percival, J. Jr-M. Lin, D. E. Shallcross, L. Sheps, S. J. Klippenstein, C. A. Taatjes & M. I. Lester, Proceedings of the National Academy of Sciences (2020) Link 

The reaction of hydroxyl and methylperoxy radicals is not a major source of atmospheric methanol, R. L. Caravan, M. A. H. Khan, J. Zádor, L. Sheps, I. O. Antonov, B. Rotavera, K. Ramasesha, K. Au, M.-W. Chen, D. Rösch, D. L. Osborn, C. Fittschen, C. Schoemaecker, M. Duncianu, A. Grira, S. Dusanter, A. Tomas, C. J. Percival, D. E. Shallcross & C. A. Taatjes, Nature Communications (2018) Link

Criegee intermediates and their impacts on the troposphere, M. A. H. Khan, C. J. Percival, R. L. Caravan, C. A. Taatjes & D. E. Shallcross, Environmental Science: Processes & Impacts (2018) Link

Products of Criegee intermediate reactions with NO₂: experimental measurements and tropospheric implications,  R. L. Caravan, M. A. H. Khan, B. Rotavera, E. Papajak, I. O. Antonov, M.-W. Chen, K. Au, W. Chao, D. L. Osborn, J. Jr-M. Lin, C. J. Percival, D. E. Shallcross & C. A. Taatjes, Faraday Discussions (2017) Link

A combined experimental and theoretical study of reactions between the hydroxyl radical and oxygenated hydrocarbons relevant to astrochemical environments, R. J. Shannon, R. L. Caravan, M. A. Blitz & D. E. Heard, Physical Chemistry Chemical Physics (2014) Link