Unveiling the Reaction Dynamics of Electron-Induced Chemical Reactions: A Femtosecond Time-Resolved Mass-Spectrometry Approach

ORAL

Abstract

Electron-induced chemical reactions represent a fundamental yet complex phenomenon with significant implications in various fields such as astrochemistry, atmospheric chemistry, and plasma processing. When energetic electrons collide with molecules, they impart sufficient energy to induce electron loss and bond breakage, forming multiple ions. Our understanding of the mechanisms underlying the formation of tens to hundreds of ions from medium-sized molecules, as it occurs in mass spectrometry, remains limited, primarily due to challenges in tracking the reaction dynamics with femtosecond time resolution. In this presentation, we introduce a novel approach based on the strong-field electron recollision processes, recognized by the 2023 Physics Nobel Prize, to achieve time-resolved electron-induced chemical reactions. Leveraging femtosecond time-resolved electron-ionization mass spectrometry, our laboratory has investigated various molecular rearrangements, including the McLafferty rearrangement, retro-Diels Alder reaction, and neutral species roaming. Our experimental observations shed light on the ultrafast dynamics following electron-induced reactions, providing insights into high-energy chemical processes characterized by multiple ionization and fragmentation pathways. Moreover, our findings contribute to validating quantum mechanical models aimed at predicting product ion distributions, thus advancing our understanding of electron-molecule interactions and their broader implications.

*Time-resolved electron ionization mass spectrometry is based upon work supported by the Air Force Office of Scientific Research under award number FA9550-21-1-0428. The initial work on strong field ionization and development of disruptive probing is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Atomic, Molecular and Optical Sciences Program under Award Number SISGR (DE-SC0002325).

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Publication: J. Stamm, S. Kwon, S. Sandhu, B. G. Levine and M. Dantus. "Coherence mapping to identify the intermediates of multi-channel dissociative ionization." J. Chem. Phys. 7, 103 (2024).
M. Dantus " Tracking Molecular Fragmentation in Electron-Ionization Mass Spectrometry with Ultrafast Time Resolution," Acc. Chem. Res. 033003 (2024).
J. Stamm, S. Kwon, S. Sandhu, M. Shaik, R. Das, J. Sandhu, B. Curenton, C. Wicka, B. G. Levine, L. Sun, M. Dantus, "The Surprising Dynamics of the McLafferty Rearrangement ," J. Phys. Chem. Lett. 14,44, 10088-10093 (2023).
S. Kwon, S. Sandhu, M. Shaik, J. Stamm, J. Sandhu, R. Das, C. V. Hetherington, B. G. Levine, M. Dantus, "What is the mechanism of H3+ Formation from Cyclopropane?," J. Phys. Chem. A. 127,41, 8633-8638 (2023).
J. Stamm, S. Li, B. Jochim, S. Yuwono, S. Priyadarsini, P. Piecuch, M. Dantus, "Femtosecond intramolecular rearrangement of the CH3NCS radical cation", J. Chem. Phys. 157, 214304 (2022).
B. Jochim, L. DeJesus, M. Dantus, "Ultrafast disruptive probing: simultaneously keeping track of tens of reaction pathways,", Rev. Sci. Instr. 93, 033003 (2022).
S. Li, B. Jochim, J. E. Jackson, and M. Dantus "Femtosecond dynamics and coherence of ionic retro-Diels–Alder reactions," J. Chem. Phys. 155, 044303 (2021).
N. Ekanayake, T. Severt, M. Nairat, N. P. Weingartz, B. M. Farris, B. Kaderiya, P. Feizollah, B. Jochim, F. Ziaee, K. Borne, K. Raju P., K. D. Carnes, D. Rolles, A. Rudenko, B. G. Levine, J. E. Jackson, I. Ben-Itzhak, and M. Dantus, "H2 roaming chemistry and the formation of H3+ from organic molecules in strong laser fields," Nat. Commun. 9, 5186 (2018).
N. Ekanayake, M. Nairat, B. Kaderiya, P. Feizollah, B. Jochim, T. Severt, B. Berry, K. Raju P., K.D. Carnes, S. Pathak, D. Rolles, A. Rudenko, I. Ben-Itzhak, C.A. Mancuso, B.S. Fales, J.E. Jackson, B.G. Levine, and M. Dantus, "Mechanisms and time-resolved dynamics for trihydrogen cation (H3+) formation from organic molecules in strong laser fields," Sci. Rep. 7, 4703 (2017).

Presenters

  • Marcos Dantus

    • Michigan State University

Authors

  • Marcos Dantus

    • Michigan State University