Photoinduced Electron Transfer Coupled to Donor Deprotonation and Acceptor Protonation in a Molecular Triad Mimicking Photosystem II

Published on 2017-09-14T15:20:04Z (GMT) by
The first artificial donor–sensitizer–acceptor compound in which photoinduced long-range electron transfer is coupled to donor deprotonation and acceptor protonation is reported. The long-lived photoproduct stores energy in the form of a radical pair state in which the charges of the donor and the acceptor remain unchanged, much in contrast to previously investigated systems that exhibit charge-separated states comprised of electron–hole pairs. This finding is relevant for light-driven accumulation of redox equivalents, because it exemplifies how the buildup of charge can be avoided yet light energy can be stored. Proton-coupled electron transfer (PCET) reactions at a phenol donor and a monoquat acceptor triggered by excitation of a Ru­(II) sensitizer enable this form of photochemical energy storage. Our triad emulates photosystem II more closely than previously investigated systems, because tyrosine Z is oxidized and deprotonated, whereas plastoquinone B is reduced and protonated.

Cite this collection

Pannwitz, Andrea; Wenger, Oliver S. (2017): Photoinduced

Electron Transfer Coupled to Donor Deprotonation

and Acceptor Protonation in a Molecular Triad Mimicking Photosystem

II. ACS Publications.

https://doi.org/10.1021/jacs.7b08761

Retrieved: 10:21, Sep 24, 2017 (GMT)