Kinetics teach that electronic coupling lowers the free-energy change that accompanies electron transfer

Journal Article · 25 June 2018 · Proceedings of the National Academy of Sciences of the United States of America

DOI: https://doi.org/10.1073/pnas.1722401115 · OSTI ID:1457096

Sampaio, Renato N.  ^[1]; Piechota, Eric J. ^[1]; Troian-Gautier, Ludovic ^[1]; Maurer, Andrew B. ^[1]; Hu, Ke ^[2]; Schauer, Phil A. ^[3]; Blair, Amber D. ^[3]; Berlinguette, Curtis P. ^[3]; Meyer, Gerald J. ^[1]

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1. Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3290,
2. Department of Chemistry, Fudan University, 200433 Shanghai, People’s Republic of China,
3. Department of Chemistry, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada,, Department of Chemical &, Biological Engineering, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada,, The Stewart Blusson Quantum Matter Institute, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada

Significance Nature’s use of electronic coupling (H _DA ) and free-energy (ΔG ^o ) gradients to vectorially control electron transport provides inspiration for artificial photosynthesis. Theoretical predictions indicate that H _DA and ΔG ^o are not independent parameters, and are instead linked. Reported here is a broadly applicable kinetic approach that was utilized to demonstrate such behavior for four acceptor–bridge–donor compounds. When the electronic coupling was large and electron transfer was adiabatic, the free energy of the reaction |ΔG ^o | was less than that for nonadiabatic transfer. This finding should be taken into account in the design of hybrid materials for solar energy conversion and has broad implications to the many classes of electron-transfer reactions in biology and chemistry.

• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: SC0013461
• OSTI ID: 1457096
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America, Journal Name: Proceedings of the National Academy of Sciences of the United States of America Journal Issue: 28 Vol. 115; ISSN 0027-8424
• Publisher: Proceedings of the National Academy of SciencesCopyright Statement
• Country of Publication: United States
• Language: English