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Zarrabi N, Seetharaman S, Chaudhuri S, Holzer N, Batista VS, van der Est A, D'Souza F, Poddutoori PK. Decelerating Charge Recombination Using Fluorinated Porphyrins in N,N-Bis(3,4,5-trimethoxyphenyl)aniline-Aluminum(III) Porphyrin-Fullerene Reaction Center Models. J Am Chem Soc 2020; 142:10008-10024. [PMID: 32343561 DOI: 10.1021/jacs.0c01574] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
In supramolecular reaction center models, the lifetime of the charge-separated state depends on many factors. However, little attention has been paid to the redox potential of the species that lie between the donor and acceptor in the final charge separated state. Here, we report on a series of self-assembled aluminum porphyrin-based triads that provide a unique opportunity to study the influence of the porphyrin redox potential independently of other factors. The triads, BTMPA-Im→AlPorFn-Ph-C60 (n = 0, 3, 5), were constructed by linking the fullerene (C60) and bis(3,4,5-trimethoxyphenyl)aniline (BTMPA) to the aluminum(III) porphyrin. The porphyrin (AlPor, AlPorF3, or AlPorF5) redox potentials are tuned by the substitution of phenyl (Ph), 3,4,5-trifluorophenyl (PhF3), or 2,3,4,5,6-pentafluorophenyl (PhF5) groups in its meso positions. The C60 and BTMPA units are bound axially to opposite faces of the porphyrin plane via covalent and coordination bonds, respectively. Excitation of all of the triads results in sequential electron transfer that generates the identical final charge separated state, BTMPA•+-Im→AlPorFn-Ph-C60•-, which lies energetically 1.50 eV above the ground state. Despite the fact that the radical pair is identical in all of the triads, remarkably, the lifetime of the BTMPA•+-Im→AlPorFn-Ph-C60•- radical pair was found to be very different in each of them, that is, 1240, 740, and 56 ns for BTMPA-Im→AlPorF5-Ph-C60, BTMPA-Im→AlPorF3-Ph-C60, and BTMPA-Im→AlPor-Ph-C60, respectively. These results clearly suggest that the charge recombination is an activated process that depends on the midpoint potential of the central aluminum(III) porphyrin (AlPorFn).
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Affiliation(s)
- Niloofar Zarrabi
- Department of Chemistry & Biochemistry, University of Minnesota Duluth, 1038 University Drive, Duluth, Minnesota 55812, United States
| | - Sairaman Seetharaman
- Department of Chemistry, University of North Texas, 1155 Union Circle, # 305070, Denton, Texas 76203-5017, United States
| | - Subhajyoti Chaudhuri
- Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520-8107, United States
| | - Noah Holzer
- Department of Chemistry & Biochemistry, University of Minnesota Duluth, 1038 University Drive, Duluth, Minnesota 55812, United States
| | - Victor S Batista
- Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520-8107, United States
| | - Art van der Est
- Department of Chemistry, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON L2S 3A1, Canada
| | - Francis D'Souza
- Department of Chemistry, University of North Texas, 1155 Union Circle, # 305070, Denton, Texas 76203-5017, United States
| | - Prashanth K Poddutoori
- Department of Chemistry & Biochemistry, University of Minnesota Duluth, 1038 University Drive, Duluth, Minnesota 55812, United States
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Zarrabi N, Lim GN, Bayard BJ, D'Souza F, Poddutoori PK. Surface anchored self-assembled reaction centre mimics as photoanodes consisting of a secondary electron donor, aluminium(iii) porphyrin and TiO2 semiconductor. Phys Chem Chem Phys 2019; 21:19612-19622. [DOI: 10.1039/c9cp03400e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Vertically assembled photoanodes, consisting of aluminum(iii) porphyrin, an electron donor, and semiconductor TiO2, have been fabricated and their photophysical properties investigated.
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Affiliation(s)
- Niloofar Zarrabi
- Department of Chemistry & Biochemistry
- University of Minnesota Duluth
- Duluth
- USA
| | - Gary N. Lim
- Department of Chemistry
- University of North Texas
- Denton
- USA
| | - Brandon J. Bayard
- Department of Chemistry & Biochemistry
- University of Minnesota Duluth
- Duluth
- USA
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Buntkowsky G, Ivanov K, Vieth HM. From Free Radicals and Spin-Chemistry Over Spin-Dynamics and Hyperpolarization to Biology and Materials Science. Z PHYS CHEM 2017. [DOI: 10.1515/zpch-2016-5006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Gerd Buntkowsky
- Technische Universität Darmstadt, Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Alarich-Weiss-Straße 4, Darmstadt 64287, Germany
| | - Konstantin Ivanov
- International Tomography Center, Institutskaya 3A, Novosibirsk 630090, Russia
- Novosibirsk State University, Pirogova 2, Novosibirsk 630090, Russia
| | - Hans-Martin Vieth
- International Tomography Center, Institutskaya 3A, Novosibirsk 630090, Russia
- Freie Universität Berlin, Institut für Experimentalphysik, Arnimallee 14, Berlin 14195, Germany
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