Simulation of Solution Phase Electron Transfer in a Compact Donor-Acceptor Dyad
Name
KowalczykVanVoorhis11b.pdf
Size
1.25 MB
Format
Adobe PDF
Checksum (MD5)
3a351195d45a80f90867446e9c14cb7a
Author(s)
Kowalczyk, Timothy Daniel
Wang, Lee-Ping
Van Voorhis, Troy
Date Issued
September 2011
Journal
Journal of Physical Chemistry B
Publisher
American Chemical Society
Citation
Kowalczyk, Tim, Lee-Ping Wang, and Troy Van Voorhis. “Simulation of Solution Phase Electron Transfer in a Compact Donor–Acceptor Dyad.” The Journal of Physical Chemistry B 115.42 (2011): 12135–12144. Web.
Version
Author's final manuscript
Abstract
Charge separation (CS) and charge recombination (CR) rates in photosynthetic architectures are difficult to control, yet their ratio can make or break photon-to-current conversion efficiencies. A rational design approach to the enhancement of CS over CR requires a mechanistic understanding of the underlying electron-transfer (ET) process, including the role of the environment. Toward this goal, we introduce a QM/MM protocol for ET simulations and use it to characterize CR in the formanilide–anthraquinone dyad (FAAQ). Our simulations predict fast recombination of the charge-transfer excited state, in agreement with recent experiments. The computed electronic couplings show an electronic state dependence and are weaker in solution than in the gas phase. We explore the role of cis–trans isomerization on the CR kinetics, and we find strong correlation between the vertical energy gaps of the full simulations and a collective solvent polarization coordinate. Our approach relies on constrained density functional theory to obtain accurate diabatic electronic states on the fly for molecular dynamics simulations, while orientational and electronic polarization of the solvent is captured by a polarizable force field based on a Drude oscillator model. The method offers a unified approach to the characterization of driving forces, reorganization energies, electronic couplings, and nonlinear solvent effects in light-harvesting systems.
MIT Department
Massachusetts Institute of Technology. Department of Chemistry
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1021/jp204962k
