Abstract
We have designed and synthesized a molecular dyad comprising a carotenoid pigment linked to a fullerene derivative (C-C60) in which the carotenoid acts both as an antenna for the fullerene and as an electron transfer partner. Ultrafast transient absorption spectroscopy was carried out on the dyad in order to investigate energy transfer and charge separation pathways and efficiencies upon excitation of the carotenoid moiety. When the dyad is dissolved in hexane energy transfer from the carotenoid S2 state to the fullerene takes place on an ultrafast (sub 100 fs) timescale and no intramolecular electron transfer was detected. When the dyad is dissolved in toluene, the excited carotenoid decays from its excited states both by transferring energy to the fullerene and by forming a charge-separated C•+-C60•−. The charge-separated state is also formed from the excited fullerene following energy transfer from the carotenoid. These pathways lead to charge separation on the subpicosecond time scale (possibly from the S2 state and the vibrationally excited S1 state of the carotenoid), on the ps time scale (5.5 ps) from the relaxed S1 state of the carotenoid, and from the excited state of C60 in 23.5 ps. The charge-separated state lives for 1.3 ns and recombines to populate both the low-lying carotenoid triplet state and the dyad ground state.
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H. A. Frank and R. J. Cogdell, Carotenoids in photosynthesis, Photochem. Photobiol., 1996, 63, 257–264.
T. Polívka, V. Sundström, Ultrafast dynamics of carotenoid excited states—from solution to natural and artificial systems, Chem. Rev., 2004, 104, 2021–2071.
N. E. Holt, G. R. Fleming and K. K. Niyogi, Toward an understanding of the mechanism of nonphotochemical quenching in green plants, Biochemistry, 2004, 43, 8281–8289.
N. E. Holt, D. Zigmantas, L. Valkunas, X. P. Li, K. K. Niyogi and G. R. Fleming, Carotenoid cation formation and the regulation of photosynthetic light harvesting, Science, 2005, 307, 433–436.
R. Berera, C. Herrero, I. H. M. van Stokkum, M. Vengris, G. Kodis, R. E. Palacios, H. van Amerongen, R. van Grondelle, D. Gust, T. A. Moore, A. L. Moore, J. T. M. Kennis, A simple artificial light-harvesting dyad as a model for excess energy dissipation in oxygenic photosynthesis, Proc. Natl. Acad. Sci. U. S. A., 2006, 103, 5343–5348.
J. S. Vretos, D. H. Steward, J. D. de Paula and G. W. Brudvig, Low-temperature optical and resonance Raman spectra of a carotenoid cation radical in photosystem II, J. Phys. Chem. B, 1999, 103, 6403–6406.
P. Faller, A. Pascal and A. W. Rutherford, ß-Carotene redox reactions in photosystem II: electron transfer pathway, Biochemistry, 2001, 40, 6431–6440.
P. A. Liddell, J. P. Sumida, A. N. Macpherson, L. Noss, G. R. Seely, K. N. Clark, A. L. Moore, T. A. Moore and D. Gust, Preparation and photophysical studies of porphyrin C-60 dyads, Photochem. Photobiol., 1994, 60, 537–541.
R. M. Williams, J. M. Zwier and J. W. Verhoeven, Photoinduced intramolecular electron-transfer in a bridged C60 (acceptor) aniline (donor) system-photophysical properties of the first active fullerene diad, J. Am. Chem. Soc., 1995, 117, 4093–4099.
D. Kuciauskas, P. A. Liddell, S. Lin, S. G. Stone, A. L. Moore, T. A. Moore and D. Gust, Photoinduced electron transfer in carotenoporphyrin–fullerene triads: temperature and solvent effects, J. Phys. Chem. B, 2000, 104, 4307–4321.
D. M. Guldi, Fullerene-porphyrin architectures; photosynthetic antenna and reaction center models, Chem. Soc. Rev., 2002, 31, 22–36.
H. Imahori, K. Hagiwara, T. Akiyama, M. Aoki, S. Taniguchi, T. Okada, M. Shirakawa and Y. Sakata, The small reorganization energy of C-60 in electron transfer, Chem. Phys. Lett., 1996, 263, 545–550.
D. Gust, T. A. Moore and A. L. Moore, Mimicking photosynthetic solar energy transduction, Acc. Chem. Res., 2001, 34, 40–48.
C. C. Gradinaru, I. H. M. van Stokkum, A. A. Pascal, R. van Grondelle and H. van Amerongen, Identifying the pathways of energy transfer between carotenoids and chlorophylls in LHCII and CP29. A multicolor, femtosecond pump–probe study, J. Phys. Chem. B, 2000, 104, 9330–9342.
I. H. M. van Stokkum, D. S. Larsen and R. van Grondelle, Global and target analysis of time-resolved spectra, Biochim. Biophys. Acta, 2004, 1657, 82–104.
D. Gust, T. A. Moore, A. L. Moore and P. A. Liddell, Synthesis of carotenoporphyrin models for photosynthetic energy and electron-transfer, Methods Enzymol., 1992, 213, 87–100.
H. H. Billsten, D. Zigmantas, V. Sundström, T. Polívka, Dynamics of vibrational relaxation in the S1 state of carotenoids having 11 conjugated C?C bonds, Chem. Phys. Lett., 2002, 355, 465–470.
F. L. de Weerd, I. H. M. van Stokkum and R. van Grondelle, Subpicosecond dynamics in the excited state absorption of all-trans-ß-Carotene, Chem. Phys. Lett., 2002, 354, 38–43.
R. J. Cogdell, E. J. Land and T. G. Truscott, The triplet extinction coefficients of some bacterial carotenoids, Photochem. Photobiol., 1983, 38, 723–725.
B. R. Nielsen, K. J?rgensen and L. H. Skibsted, Triplet–triplet extinction coefficients, rate constants of triplet decay and rate constants of antracene triplet sensitization by laser flash photolysis of astaxanthin, ß-carotene, canthaxanthin and zeaxanthin in deaerated toluene at 298 K, J. Photochem. Photobiol., A, 1998, 112, 127–133.
E. Papagiannakis, I. H. M. van Stokkum, R. van Grondelle, R. A. Niederman, D. Zigmantas, V. Sundström, T. Polívka, A near-infrared transient absorption study of the excited-state dynamics of the carotenoid spirilloxanthin in solution and in the LH1 complex of Rhodospirillum rubrum, J. Phys. Chem. B, 2003, 107, 11216–11223.
E. J. Land, D. Lexa, R. V. Bensasson, D. Gust, T. A. Moore, A. L. Moore, P. A. Liddell and G. A. Nemeth, Pulse radiolytic and electrochemical investigations of intramolecular electron-transfer in carotenoporphyrins and carotenoporphyrin quinone triads, J. Phys. Chem., 1987, 91, 4831–4835.
M. A. Greaney and S. M. Gorun, Production, spectroscopy, and electronic structure of soluble fullerene ions, J. Phys. Chem., 1991, 95, 7142–7144.
E. Papagiannakis, J. T. M. Kennis, I. H. M. van Stokkum, R. J. Cogdell and R. van Grondelle, An alternative carotenoid-to-bacteriochlorophyll energy transfer pathway in photosynthetic light harvesting, Proc. Natl. Acad. Sci. U. S. A., 2002, 99, 6017–6022.
G. Kodis, C. Herrero, R. Palacios, E. Marino-Ochoa, S. Gould, L. de la Garza, R. van Grondelle, D. Gust, T. A. Moore, A. L. Moore, J. T. M. Kennis, Light harvesting and photoprotective functions of carotenoids in compact artificial photosynthetic antenna designs, J. Phys. Chem. B, 2004, 108, 414–425.
G. D. Scholes, X. J. Jordanides and G. R. Fleming, Adapting the Förster theory of energy transfer for modeling dynamics in aggregated molecular assemblies, J. Phys. Chem. B, 2001, 105, 1640–1651.
N. E. Holt, J. T. M. Kennis and G. R. Fleming, Femtosecond fluorescence upconversion studies of light harvesting by ß-carotene in oxygenic photosynthetic core proteins, J. Phys. Chem. B, 2004, 108, 19029–19035.
J. Pan, G. Benko, Y. H. Xu, T. Pascher, L. Sun, V. Sundström, T. Polívka, Photoinduced electron transfer between a carotenoid and TiO2 nanoparticle, J. Am. Chem. Soc., 2002, 124, 13949–13957.
H. Imahori, S. Cardoso, D. Tatman, S. Lin, L. Noss, G. R. Seely, L. Sereno, J. C. de Silber, T. A. Moore, A. L. Moore and D. Gust, Photoinduced electron transfer in a carotenobuckminsterfullerene dyad, Photochem. Photobiol., 1995, 62, 1009–1014.
R. M. Hermant, P. A. Liddell, S. Lin, R. G. Alden, H. K. Kang, A. L. Moore, T. A. Moore and D. Gust, Mimicking carotenoid quenching of chlorophyll fluorescence, J. Am. Chem. Soc., 1993, 115, 2080–2081.
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Berera, R., Moore, G.F., van Stokkum, I.H.M. et al. Charge separation and energy transfer in a caroteno—C60 dyad: photoinduced electron transfer from the carotenoid excited states. Photochem Photobiol Sci 5, 1142–1149 (2006). https://doi.org/10.1039/b613971j
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DOI: https://doi.org/10.1039/b613971j