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Sutherland G, Pidgeon JP, Lee HKH, Proctor MS, Hitchcock A, Wang S, Chekulaev D, Tsoi WC, Johnson MP, Hunter CN, Clark J. Twisted Carotenoids Do Not Support Efficient Intramolecular Singlet Fission in the Orange Carotenoid Protein. J Phys Chem Lett 2023; 14:6135-6142. [PMID: 37364284 PMCID: PMC10331831 DOI: 10.1021/acs.jpclett.3c01139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 06/22/2023] [Indexed: 06/28/2023]
Abstract
Singlet exciton fission is the spin-allowed generation of two triplet electronic excited states from a singlet state. Intramolecular singlet fission has been suggested to occur on individual carotenoid molecules within protein complexes provided that the conjugated backbone is twisted out of plane. However, this hypothesis has been forwarded only in protein complexes containing multiple carotenoids and bacteriochlorophylls in close contact. To test the hypothesis on twisted carotenoids in a "minimal" one-carotenoid system, we study the orange carotenoid protein (OCP). OCP exists in two forms: in its orange form (OCPo), the single bound carotenoid is twisted, whereas in its red form (OCPr), the carotenoid is planar. To enable room-temperature spectroscopy on canthaxanthin-binding OCPo and OCPr without laser-induced photoconversion, we trap them in a trehalose glass. Using transient absorption spectroscopy, we show that there is no evidence of long-lived triplet generation through intramolecular singlet fission despite the canthaxanthin twist in OCPo.
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Affiliation(s)
- George
A. Sutherland
- Plants,
Photosynthesis and Soil, School of Biosciences, University of Sheffield, Sheffield S10 2TN, U.K.
| | - James P. Pidgeon
- Department
of Physics and Astronomy, University of
Sheffield, Sheffield S3 7RH, U.K.
| | - Harrison Ka Hin Lee
- SPECIFIC,
Faculty of Science and Engineering, Swansea
University, Swansea SA1 8EN, U.K.
| | - Matthew S. Proctor
- Plants,
Photosynthesis and Soil, School of Biosciences, University of Sheffield, Sheffield S10 2TN, U.K.
| | - Andrew Hitchcock
- Plants,
Photosynthesis and Soil, School of Biosciences, University of Sheffield, Sheffield S10 2TN, U.K.
| | - Shuangqing Wang
- Department
of Physics and Astronomy, University of
Sheffield, Sheffield S3 7RH, U.K.
| | - Dimitri Chekulaev
- Department
of Chemistry, University of Sheffield, Sheffield S3 7HF, U.K.
| | - Wing Chung Tsoi
- SPECIFIC,
Faculty of Science and Engineering, Swansea
University, Swansea SA1 8EN, U.K.
| | - Matthew P. Johnson
- Plants,
Photosynthesis and Soil, School of Biosciences, University of Sheffield, Sheffield S10 2TN, U.K.
| | - C. Neil Hunter
- Plants,
Photosynthesis and Soil, School of Biosciences, University of Sheffield, Sheffield S10 2TN, U.K.
| | - Jenny Clark
- Department
of Physics and Astronomy, University of
Sheffield, Sheffield S3 7RH, U.K.
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Vogeler F, Siegert S, Marian CM, Weinkauf R. T1, T2 State Energies and Electron Affinities of Small α,ω-Diphenylpolyenes Investigated by Anion Photodetachment Photoelectron Spectroscopy and Excited-State Theory. Chemphyschem 2011; 12:1948-56. [DOI: 10.1002/cphc.201001083] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2010] [Revised: 04/04/2011] [Indexed: 11/08/2022]
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Weiss V, Port H, Wolf HC. Excitonic and Molecular Properties of the TripletT1-State in Diphenylpolyene Single Crystals. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/10587259708045102] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- V. Weiss
- a Physikalisches Institut der Universität Stuttgart , Pfaffenwaldring 57, 70550 , Stuttgart , Germany
| | - H. Port
- a Physikalisches Institut der Universität Stuttgart , Pfaffenwaldring 57, 70550 , Stuttgart , Germany
| | - H. C. Wolf
- a Physikalisches Institut der Universität Stuttgart , Pfaffenwaldring 57, 70550 , Stuttgart , Germany
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Barbon A, Bortolus M, Brustolon M, Maniero AL, Zanrè R. Photoexcited triplets of nitrodiphenylpolyenes hosted in channel cavities. A time resolved EPR study. Phys Chem Chem Phys 2004. [DOI: 10.1039/b400902a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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