Dipole Effects on Electron Transfer are Enormous. Issue 38 (14th June 2018)

• Record Type: Journal Article
• Authors: Krzeszewski, Maciej; Espinoza, Eli M.; Červinka, Ctirad; Derr, James B.; Clark, John A.; Borchardt, Dan; Beran, Gregory J. O.; Gryko, Daniel T.; Vullev, Valentine I.
• Is Part Of: Angewandte Chemie international edition. Volume 57:Issue 38(2018)
• Page Start: 12365
• Page End: 12369
• Publication Date: 2018-06-14
• Subjects: charge transfer -- dipoles -- electron transfer -- kinetics -- Rehm-Weller equation; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201802637
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Molecular dipoles present important, but underutilized, methods for guiding electron transfer (ET) processes. While dipoles generate fields of Gigavolts per meter in their vicinity, reported differences between rates of ET along versus against dipoles are often small or undetectable. Herein we show unprecedentedly large dipole effects on ET. Depending on their orientation, dipoles either ensure picosecond ET, or turn ET completely off. Furthermore, favorable dipole orientation makes ET possible even in lipophilic medium, which appears counterintuitive for non‐charged donor–acceptor systems. Our analysis reveals that dipoles can substantially alter the ET driving force for low solvent polarity, which accounts for these unique trends. This discovery opens doors for guiding forward ET processes while suppressing undesired backward electron transduction, which is one of the holy grails of photophysics and energy science. Abstract : Live and let dipole : The electric dipole of a donor strongly affects the electron transfer (ET) to a photoexcited acceptor. Decreasing the polarity of the medium increases the rates of electron transfer along the dipole, while completely suppressing the electron transfer against it. A favorable dipole orientation makes ET possible even in lipophilic medium, which is counterintuitive for non‐charged donor–acceptor systems.