High-Energy Charge-Separated States by Reductive Electron Transfer Followed by Electron Shift in the Tetraphenylethylene–Aluminum(III) Porphyrin–Fullerene Triad

Zarrabi, Niloofar; Agatemor, Christian; Lim, Gary N.; Matula, Adam J.; Bayard, Brandon J.; Batista, Victor S.; D’Souza, Francis; Poddutoori, Prashanth K.

doi:10.1021/acs.jpcc.8b09500

Title: High-Energy Charge-Separated States by Reductive Electron Transfer Followed by Electron Shift in the Tetraphenylethylene–Aluminum(III) Porphyrin–Fullerene Triad

Journal Article · 06 December 2018 · Journal of Physical Chemistry. C

DOI: https://doi.org/10.1021/acs.jpcc.8b09500 · OSTI ID:1543657

Zarrabi, Niloofar ^[1]; Agatemor, Christian ^[2]; Lim, Gary N. ^[3]; Matula, Adam J. ^[4]; Bayard, Brandon J. ^[1];

^[4];

^[3];

^[1]

Univ. of Minnesota at Duluth, Duluth, MN (United States)
Johns Hopkins Univ. School of Medicine, Baltimore, MD (United States)
Univ. of North Texas, Denton, TX (United States)
Yale Univ., New Haven, CT (United States)

A high-potential supramolecular triad (TPE-AlPor ← Im-C₆₀) composed of aluminum(III) porphyrin (AlPor), fullerene (C₆₀), and tetraphenylethylene (TPE) has been constructed. The fullerene and tetraphenylethylene units are bound axially to opposite faces of the porphyrin plane via coordination and covalent bonds, respectively. The ground and excited-state properties of the triad and reference dyads are studied using steady-state and time-resolved spectroscopic techniques. The transient data show that photoexcitation results in charge separation from tetraphenylethylene to the excited singlet state of the porphyrin (¹AlPor*), generating a high-energy (2.14 eV) charge-separated state, (TPE)^•+-(AlPor)^•–, in toluene. A subsequent electron migration from the AlPor^–• to fullerene generates a second high-energy (1.78 eV) charge-separated state (TPE)^•+-AlPor ← Im-(C60)^•–. The lifetime of the charge separation is about 25 ns. Here, the high energy stored in the form of charge-separated states along with their reasonable lifetimes makes these donor–acceptor systems potential electron-transporting catalysts to carry out energy-demanding photochemical reactions, especially in artificial photosynthesis for conversion of solar energy into chemical energy.

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Research Organization:: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Energy Frontier Research Centers (EFRC) (United States); Northwestern Univ., Evanston, IL (United States)

Sponsoring Organization:: National Science Foundation; USDOE Office of Science (SC)

Grant/Contract Number:: SC0001059

OSTI ID:: 1543657

Journal Information:: Journal of Physical Chemistry. C, Journal Name: Journal of Physical Chemistry. C Journal Issue: 1 Vol. 123; ISSN 1932-7447

Publisher:: American Chemical SocietyCopyright Statement

Country of Publication:: United States

Language:: English

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Title: High-Energy Charge-Separated States by Reductive Electron Transfer Followed by Electron Shift in the Tetraphenylethylene–Aluminum(III) Porphyrin–Fullerene Triad

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