Attochemistry Regulation of Charge Migration
Aderonke S. Folorunso, François Mauger, Kyle Hamer, Denawakage D. Jayasinghe, Imam S. Wahyutama, Justin R. Ragains, R. R. Jones, Louis F. DiMauro, Mette B. Gaarde, Kenneth J. Schäfer, Kenneth A. Lopata
Abstract
High Resolution Image Download MS PowerPoint Slide 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–C 6 H 4 –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 → C 6 H 4 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 σ 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.