Aderonke S. Folorunso [1], François Mauger [1], Kyle A. Hamer [1], Denawakage Jayasinghe [1], Imam Setiawan Wahyutama [2], Justin Ragains [1], Robert R. Jones [3], Louis F. DiMauro [4], Mette B. Gaarde [2], Kenneth J. Schafer [2], and Kenneth Lopata [2,3]
[1] Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, USA
[2] Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
[3] Department of Physics, University of Virginia, Charlottesville, Virginia 22904, USA
[4] Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
[5] Center for Computation and Technology, Louisiana State University, Baton Rouge, Louisiana 70808, US
Abstract:Charge migration (CM) is a coherent attosecond process that involves the movement of localized holes across a molecule. To determine the relationship between a molecule’s structure and the CM dynamics it exhibits, we perform systematic studies of para-functionalized bromobenzene molecules(X-C6H4-R) using real-time time-dependent density functional theory. We initiate valence-electron dynamics by emulating rapid strong-field ionization leading to a localized hole on the bromine atom. The resulting CM, which takes on the order of 1 fs, occurs via an X localized ? C6H4 delocalized ? R localized mechanism. Interestingly, the hole contrast on the acceptor functional group increases with increasing electron-donating strength. This trend is well-described by the Hammett s value of the group, which is a commonly used metric for quantifying the effect of functionalization on the chemical reactivity of benzene derivatives. These results suggest that simple attochemistry principles and a density-based picture can be used to predict and understand CM.
Published: J. Phys. Chem. A 127, 1894 (2023).
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