1
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Beck WF. Intramolecular charge transfer and the function of vibronic excitons in photosynthetic light harvesting. PHOTOSYNTHESIS RESEARCH 2024:10.1007/s11120-024-01095-5. [PMID: 38656684 DOI: 10.1007/s11120-024-01095-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Accepted: 03/15/2024] [Indexed: 04/26/2024]
Abstract
A widely discussed explanation for the prevalence of pairs or clusters of closely spaced electronic chromophores in photosynthetic light-harvesting proteins is the presence of ultrafast and highly directional excitation energy transfer pathways mediated by vibronic excitons, the delocalized optical excitations derived from mixing of the electronic and vibrational states of the chromophores. We discuss herein the hypothesis that internal conversion processes between exciton states on the <100 fs timescale are possible when the excitonic potential energy surfaces are controlled by the vibrational modes that induce charge transfer character in a strongly coupled system of chromophores. We discuss two examples, the peridinin-chlorophyll protein from marine dinoflagellates and the intact phycobilisome from cyanobacteria, in which the intramolecular charge-transfer (ICT) character arising from out-of-plane distortion of the conjugation of carotenoid or bilin chromophores also results in localization of the initially delocalized optical excitation on the vibrational timescale. Tuning of the ground state conformations of the chromophores to manipulate their ICT character provides a natural photoregulatory mechanism, which would control the overall quantum yield of excitation energy transfer by turning on and off the delocalized character of the optical excitations.
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Affiliation(s)
- Warren F Beck
- Department of Chemistry, Michigan State University, East Lansing, MI, 48824, USA.
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2
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The Energy Transfer Yield between Carotenoids and Chlorophylls in Peridinin Chlorophyll a Protein Is Robust against Mutations. Int J Mol Sci 2022; 23:ijms23095067. [PMID: 35563456 PMCID: PMC9099807 DOI: 10.3390/ijms23095067] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 04/29/2022] [Accepted: 04/29/2022] [Indexed: 12/12/2022] Open
Abstract
The energy transfer (ET) from carotenoids (Cars) to chlorophylls (Chls) in photosynthetic complexes occurs with almost unitary efficiency thanks to the synergistic action of multiple finely tuned channels whose photophysics and dynamics are not fully elucidated yet. We investigated the energy flow from the Car peridinin (Per) to Chl a in the peridinin chlorophyll a protein (PCP) from marine algae Amphidinium carterae by using two-dimensional electronic spectroscopy (2DES) with a 10 fs temporal resolution. Recently debated hypotheses regarding the S2-to-S1 relaxation of the Car via a conical intersection and the involvement of possible intermediate states in the ET were examined. The comparison with an N89L mutant carrying the Per donor in a lower-polarity environment helped us unveil relevant details on the mechanisms through which excitation was transferred: the ET yield was conserved even when a mutation perturbed the optimization of the system thanks to the coexistence of multiple channels exploited during the process.
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Kosumi D, Kusumoto T, Hashimoto H. Unique ultrafast excited states dynamics of artificial short-polyene carotenoid analog 2-(all-trans-β-ionylideneetinylidene)-indan-1,3-dione. J Photochem Photobiol A Chem 2021. [DOI: 10.1016/j.jphotochem.2021.113424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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4
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Mohan T M N, Leslie CH, Sil S, Rose JB, Tilluck RW, Beck WF. Broadband 2DES detection of vibrational coherence in the S x state of canthaxanthin. J Chem Phys 2021; 155:035103. [PMID: 34293883 DOI: 10.1063/5.0055598] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The nonadiabatic mechanism that mediates nonradiative decay of the bright S2 state to the dark S1 state of carotenoids involves population of a bridging intermediate state, Sx, in several examples. The nature of Sx remains to be determined definitively, but it has been recently suggested that Sx corresponds to conformationally distorted molecules evolving along out-of-plane coordinates of the isoprenoid backbone near a low barrier between planar and distorted conformations on the S2 potential surface. In this study, the electronic and vibrational dynamics accompanying the formation of Sx in toluene solutions of the ketocarotenoid canthaxanthin (CAN) are characterized with broadband two-dimensional electronic spectroscopy (2DES) with 7.8 fs excitation pulses and detection of the linear polarization components of the third-order nonlinear optical signal. A stimulated-emission cross peak in the 2DES spectrum accompanies the formation of Sx in <20 fs following excitation of the main absorption band. Sx is prepared instantaneously, however, with excitation of hot-band transitions associated with distorted conformations of CAN's isoprenoid backbone in the low frequency onset of the main absorption band. Vibrational coherence oscillation maps and modulated anisotropy transients show that Sx undergoes displacements from the Franck-Condon S2 state along out-of-plane coordinates as it passes to the S1 state. The results are consistent with the conclusion that CAN's carbonyl-substituted β-ionone rings impart an intramolecular charge-transfer character that frictionally slows the passage from Sx to S1 compared to carotenoids lacking carbonyl substitution. Despite the longer lifetime, the S1 state of CAN is formed with retention of vibrational coherence after passing through a conical intersection seam with the Sx state.
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Affiliation(s)
- Nila Mohan T M
- Department of Chemistry, Michigan State University, 578 S. Shaw Lane, East Lansing, Michigan 48824, USA
| | - Chase H Leslie
- Department of Chemistry, Michigan State University, 578 S. Shaw Lane, East Lansing, Michigan 48824, USA
| | - Sourav Sil
- Department of Chemistry, Michigan State University, 578 S. Shaw Lane, East Lansing, Michigan 48824, USA
| | - Justin B Rose
- Department of Chemistry, Michigan State University, 578 S. Shaw Lane, East Lansing, Michigan 48824, USA
| | - Ryan W Tilluck
- Department of Chemistry, Michigan State University, 578 S. Shaw Lane, East Lansing, Michigan 48824, USA
| | - Warren F Beck
- Department of Chemistry, Michigan State University, 578 S. Shaw Lane, East Lansing, Michigan 48824, USA
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Marcolin G, Collini E. Solvent-Dependent Characterization of Fucoxanthin through 2D Electronic Spectroscopy Reveals New Details on the Intramolecular Charge-Transfer State Dynamics. J Phys Chem Lett 2021; 12:4833-4840. [PMID: 33999637 PMCID: PMC8279730 DOI: 10.1021/acs.jpclett.1c00851] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 05/12/2021] [Indexed: 05/27/2023]
Abstract
The electronic state manifolds of carotenoids and their relaxation dynamics are the object of intense investigation because most of the subtle details regulating their photophysics are still unknown. In order to contribute to this quest, here, we present a solvent-dependent 2D Electronic Spectroscopy (2DES) characterization of fucoxanthin, a carbonyl carotenoid involved in the light-harvesting process of brown algae. The 2DES technique allows probing its ultrafast relaxation dynamics in the first 1000 fs after photoexcitation with a 10 fs time resolution. The obtained results help shed light on the dynamics of the first electronic state manifold and, in particular, on an intramolecular charge-transfer state (ICT), whose photophysical properties are particularly elusive given its (almost) dark nature.
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6
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Khan T, Litvín R, Šebelík V, Polívka T. Excited-State Evolution of Keto-Carotenoids after Excess Energy Excitation in the UV Region. Chemphyschem 2021; 22:471-480. [PMID: 33373476 DOI: 10.1002/cphc.202000982] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 12/23/2020] [Indexed: 11/10/2022]
Abstract
Carotenoids are molecules with rich photophysics that are in many biological systems involved in photoprotection. Yet, their response to excess energy excitation is only scarcely studied. Here we have explored excited state properties of three keto-carotenoids, echinenone, canthaxanthin and rhodoxanthin after excess energy excitation to a singlet state absorbing in UV. Though the basic spectral features and kinetics of S2 , hot S1 , relaxed S1 states remain unchanged upon UV excitation, the clear increase of the S* signal is observed after excess energy excitation, associated with increased S* lifetime. A multiple origin of the S* signal, originating either from specific conformations in the S1 state or from a non-equilibrated ground state, is confirmed in this work. We propose that the increased amount of energy stored in molecular vibrations, induced by the UV excitation, is the reason for the enhanced S* signal observed after UV excitation. Our data also suggest that a fraction of the UV excited state population may proceed through a non-sequential pathway, bypassing the S2 state.
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Affiliation(s)
- Tuhin Khan
- Institute of Physics, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic
| | - Radek Litvín
- Institute of Chemistry, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic.,Biology Centre, Czech Academy of Sciences, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Václav Šebelík
- Institute of Physics, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic
| | - Tomáš Polívka
- Institute of Physics, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic
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7
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Gurchiek JK, Rose JB, Guberman-Pfeffer MJ, Tilluck RW, Ghosh S, Gascón JA, Beck WF. Fluorescence Anisotropy Detection of Barrier Crossing and Ultrafast Conformational Dynamics in the S 2 State of β-Carotene. J Phys Chem B 2020; 124:9029-9046. [PMID: 32955881 DOI: 10.1021/acs.jpcb.0c06961] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Carotenoids are usually only weakly fluorescent despite being very strong absorbers in the mid-visible region because their first two excited singlet states, S1 and S2, have very short lifetimes. To probe the structural mechanisms that promote the nonradiative decay of the S2 state to the S1 state, we have carried out a series of fluorescence lineshape and anisotropy measurements with a prototype carotenoid, β-carotene, in four aprotic solvents. The anisotropy values observed in the fluorescence emission bands originating from the S2 and S1 states reveal that the large internal rotations of the emission transition dipole moment, as much as 50° relative to that of the absorption transition dipole moment, are initiated during ultrafast evolution on the S2 state potential energy surface and persist upon nonradiative decay to the S1 state. Electronic structure calculations of the orientation of the transition dipole moment account for the anisotropy results in terms of torsional and pyramidal distortions near the center of the isoprenoid backbone. The excitation wavelength dependence of the fluorescence anisotropy indicates that these out-of-plane conformational motions are initiated by passage over a low-activation energy barrier from the Franck-Condon S2 structure. This conclusion is consistent with detection over the 80-200 K range of a broad, red-shifted fluorescence band from a dynamic intermediate evolving on a steep gradient of the S2 state potential energy surface after crossing the activation barrier. The temperature dependence of the oscillator strength and anisotropy indicate that nonadiabatic passage from S2 through a conical intersection seam to S1 is promoted by the out-of-plane motions of the isoprenoid backbone with strong hindrance by solvent friction.
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Affiliation(s)
- J K Gurchiek
- Department of Chemistry, Michigan State University, 578 S. Shaw Lane, East Lansing, Michigan 48824, United States
| | - Justin B Rose
- Department of Chemistry, Michigan State University, 578 S. Shaw Lane, East Lansing, Michigan 48824, United States
| | - Matthew J Guberman-Pfeffer
- Department of Chemistry, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06268-1712, United States
| | - Ryan W Tilluck
- Department of Chemistry, Michigan State University, 578 S. Shaw Lane, East Lansing, Michigan 48824, United States
| | - Soumen Ghosh
- Department of Physics, Politecnico di Milano, Piazza Leonardo da Vinci, 32, Milan, Lombardy 20133, Italy
| | - José A Gascón
- Department of Chemistry, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06268-1712, United States
| | - Warren F Beck
- Department of Chemistry, Michigan State University, 578 S. Shaw Lane, East Lansing, Michigan 48824, United States
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8
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Taffet EJ, Fassioli F, Toa ZSD, Beljonne D, Scholes GD. Uncovering dark multichromophoric states in Peridinin-Chlorophyll-Protein. J R Soc Interface 2020; 17:20190736. [PMID: 32183641 PMCID: PMC7115236 DOI: 10.1098/rsif.2019.0736] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 02/28/2020] [Indexed: 01/02/2023] Open
Abstract
It has long been recognized that visible light harvesting in Peridinin-Chlorophyll-Protein is driven by the interplay between the bright (S2) and dark (S1) states of peridinin (carotenoid), along with the lowest-lying bright (Qy) and dark (Qx) states of chlorophyll-a. Here, we analyse a chromophore cluster in the crystal structure of Peridinin-Chlorophyll-Protein, in particular, a peridinin-peridinin and a peridinin-chlorophyll-a dimer, and present quantum chemical evidence for excited states that exist beyond the confines of single peridinin and chlorophyll chromophores. These dark multichromophoric states, emanating from the intermolecular packing native to Peridinin-Chlorophyll-Protein, include a correlated triplet pair comprising neighbouring peridinin excitations and a charge-transfer interaction between peridinin and the adjacent chlorophyll-a. We surmise that such dark multichromophoric states may explain two spectral mysteries in light-harvesting pigments: the sub-200-fs singlet fission observed in carotenoid aggregates, and the sub-200-fs chlorophyll-a hole generation in Peridinin-Chlorophyll-Protein.
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Affiliation(s)
- Elliot J. Taffet
- Department of Chemistry, Princeton University, Washington Road, Princeton, NJ 08540, USA
- Department of Chemistry, University of Mons, 7000 Mons, Belgium
| | - Francesca Fassioli
- Department of Chemistry, Princeton University, Washington Road, Princeton, NJ 08540, USA
- SISSA – Scuola Internazionale Superiore di Studi Avanzati, Trieste, Italy
| | - Zi S. D. Toa
- Department of Chemistry, Princeton University, Washington Road, Princeton, NJ 08540, USA
| | - David Beljonne
- Department of Chemistry, University of Mons, 7000 Mons, Belgium
| | - Gregory D. Scholes
- Department of Chemistry, Princeton University, Washington Road, Princeton, NJ 08540, USA
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9
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Taffet EJ, Lee BG, Toa ZSD, Pace N, Rumbles G, Southall J, Cogdell RJ, Scholes GD. Carotenoid Nuclear Reorganization and Interplay of Bright and Dark Excited States. J Phys Chem B 2019; 123:8628-8643. [PMID: 31553605 DOI: 10.1021/acs.jpcb.9b04027] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report quantum chemical calculations using multireference perturbation theory (MRPT) with the density matrix renormalization group (DMRG) plus photothermal deflection spectroscopy measurements to investigate the manifold of carotenoid excited states and establish their energies relative to the bright state (S2) as a function of nuclear reorganization. We conclude that the primary photophysics and function of carotenoids are determined by interplay of only the bright (S2) and lowest-energy dark (S1) states. The lowest-lying dark state, far from being energetically distinguishable from the lowest-lying bright state along the entire excited-state nuclear reorganization pathway, is instead computed to be either the second or first excited state depending on what equilibrium geometry is considered. This result suggests that, rather than there being a dark intermediate excited state bridging a non-negligible energy gap from the lowest-lying dark state to the lowest-lying bright state, there is in fact no appreciable energy gap to bridge following photoexcitation. Instead, excited-state nuclear reorganization constitutes the bridge from S2 to S1, in the sense that these two states attain energetic degeneracy along this pathway.
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Affiliation(s)
- Elliot J Taffet
- Department of Chemistry , Princeton University , Princeton , New Jersey 08544 , United States
| | - Benjamin G Lee
- Chemical and Materials Science Center , National Renewable Energy Laboratory , Golden , Colorado 80401 , United States
| | - Zi S D Toa
- Department of Chemistry , Princeton University , Princeton , New Jersey 08544 , United States
| | - Natalie Pace
- Chemical and Materials Science Center , National Renewable Energy Laboratory , Golden , Colorado 80401 , United States
| | - Garry Rumbles
- Chemical and Materials Science Center , National Renewable Energy Laboratory , Golden , Colorado 80401 , United States
| | - June Southall
- Institute of Molecular, Cell and Systems Biology, College of Medical Veterinary and Life Sciences , University of Glasgow , University Avenue, Glasgow G12 8QQ , U.K
| | - Richard J Cogdell
- Institute of Molecular, Cell and Systems Biology, College of Medical Veterinary and Life Sciences , University of Glasgow , University Avenue, Glasgow G12 8QQ , U.K
| | - Gregory D Scholes
- Department of Chemistry , Princeton University , Princeton , New Jersey 08544 , United States
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10
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Toa ZSD, deGolian MH, Jumper CC, Hiller RG, Scholes GD. Consistent Model of Ultrafast Energy Transfer in Peridinin Chlorophyll-a Protein Using Two-Dimensional Electronic Spectroscopy and Förster Theory. J Phys Chem B 2019; 123:6410-6420. [DOI: 10.1021/acs.jpcb.9b04324] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Zi S. D. Toa
- Department of Chemistry, Princeton University, Washington Road, Princeton, New Jersey 08540, United States
| | - Mary H. deGolian
- Department of Chemistry, Princeton University, Washington Road, Princeton, New Jersey 08540, United States
| | - Chanelle C. Jumper
- Department of Chemistry, Princeton University, Washington Road, Princeton, New Jersey 08540, United States
| | - Roger G. Hiller
- Department of Biology, Faculty of Science and Engineering, Macquarie University, Sydney NSW 2109, Australia
| | - Gregory D. Scholes
- Department of Chemistry, Princeton University, Washington Road, Princeton, New Jersey 08540, United States
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11
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Ghosh R, Nandi A, Kushwaha A, Das D. Ultrafast Conformational Relaxation Dynamics in Anthryl-9-benzothiazole: Dynamic Planarization Driven Delocalization and Protonation-Induced Twisting Dynamics. J Phys Chem B 2019; 123:5307-5315. [DOI: 10.1021/acs.jpcb.9b01373] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Rajib Ghosh
- Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - Amitabha Nandi
- Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - Archana Kushwaha
- Department of Chemistry, Institute of Chemical Technology, Nathalal Parekh Marg, Matunga, Mumbai 400019, India
| | - Dipanwita Das
- Department of Chemistry, Institute of Chemical Technology, Nathalal Parekh Marg, Matunga, Mumbai 400019, India
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12
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Li H, Han J, Zhao H, Liu X, Luo Y, Shi Y, Liu C, Jin M, Ding D. Lighting Up the Invisible Twisted Intramolecular Charge Transfer State by High Pressure. J Phys Chem Lett 2019; 10:748-753. [PMID: 30704239 DOI: 10.1021/acs.jpclett.9b00026] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The twisted intramolecular charge transfer (TICT) state plays an important role in determining the performance of optoelectronic devices. However, for some nonfluorescent TICT molecules, the "invisible" TICT state could only be visualized by modifying the molecular structure. Here, we introduce a new facile pressure-induced approach to light up the TICT state through the use of a pressure-related liquid-solid phase transition of the surrounding solvent. Combining ultrafast spectroscopy and quantum chemical calculations, it reveals that the "invisible" TICT state can emit fluorescence when the rotation of a donor group is restricted by the frozen acetonitrile solution. Furthermore, the TICT process can even be effectively regulated by the external pressure. Our study offers a unique strategy to achieve dual fluorescence behavior in charge transfer molecules and is of significance for optoelectronic and biomedical applications.
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Affiliation(s)
- Hui Li
- Institute of Atomic and Molecular Physics , Jilin University , Changchun 130012 , China
| | - Jianhui Han
- Institute of Atomic and Molecular Physics , Jilin University , Changchun 130012 , China
| | - Huifang Zhao
- Institute of Atomic and Molecular Physics , Jilin University , Changchun 130012 , China
| | - Xiaochun Liu
- Institute of Atomic and Molecular Physics , Jilin University , Changchun 130012 , China
| | - Yi Luo
- Hefei National Laboratory for Physical Sciences at the Microscale , University of Science and Technology of China , Hefei , Anhui 230026 , China
| | - Ying Shi
- Institute of Atomic and Molecular Physics , Jilin University , Changchun 130012 , China
| | - Cailong Liu
- Institute of Atomic and Molecular Physics , Jilin University , Changchun 130012 , China
| | - Mingxing Jin
- Institute of Atomic and Molecular Physics , Jilin University , Changchun 130012 , China
| | - Dajun Ding
- Institute of Atomic and Molecular Physics , Jilin University , Changchun 130012 , China
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13
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Toa ZS, Dean JC, Scholes GD. Revealing structural involvement of chromophores in algal light harvesting complexes using symmetry-adapted perturbation theory. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2019; 190:110-117. [DOI: 10.1016/j.jphotobiol.2018.11.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 10/17/2018] [Accepted: 11/13/2018] [Indexed: 01/25/2023]
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15
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Roscioli JD, Ghosh S, LaFountain AM, Frank HA, Beck WF. Structural Tuning of Quantum Decoherence and Coherent Energy Transfer in Photosynthetic Light Harvesting. J Phys Chem Lett 2018; 9:5071-5077. [PMID: 30118229 DOI: 10.1021/acs.jpclett.8b01919] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Photosynthetic organisms capture energy from solar photons by constructing light-harvesting proteins containing arrays of electronic chromophores. Collective excitations (excitons) arise when energy transfer between chromophores is coherent, or wavelike, in character. Here we demonstrate experimentally that coherent energy transfer to the lowest-energy excitons is principally controlled in a light-harvesting protein by the temporal persistence of quantum coherence rather than by the strength of vibronic coupling. In the peridinin-chlorophyll protein from marine dinoflagellates, broad-band two-dimensional electronic spectroscopy reveals that replacing the native chlorophyll a acceptor chromophores with chlorophyll b slows energy transfer from the carotenoid peridinin to chlorophyll despite narrowing the donor-acceptor energy gap. The formyl substituent on the chlorophyll b macrocycle hastens decoherence by sensing the surrounding electrostatic noise. These findings demonstrate how quantum coherence enhances the efficiency of energy transfer despite being very short lived in light-harvesting proteins at physiological temperatures.
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Affiliation(s)
- Jerome D Roscioli
- Department of Chemistry , Michigan State University , East Lansing , Michigan 48824 , United States
| | - Soumen Ghosh
- Department of Chemistry , Michigan State University , East Lansing , Michigan 48824 , United States
| | - Amy M LaFountain
- Department of Chemistry , University of Connecticut , Hartford , Connecticut 06103 , United States
| | - Harry A Frank
- Department of Chemistry , University of Connecticut , Hartford , Connecticut 06103 , United States
| | - Warren F Beck
- Department of Chemistry , Michigan State University , East Lansing , Michigan 48824 , United States
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16
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Taffet EJ, Scholes GD. Peridinin Torsional Distortion and Bond-Length Alternation Introduce Intramolecular Charge-Transfer and Correlated Triplet Pair Intermediate Excited States. J Phys Chem B 2018; 122:5835-5844. [DOI: 10.1021/acs.jpcb.8b02504] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Elliot J. Taffet
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Gregory D. Scholes
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
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17
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Gurchiek JK, Bao H, Domínguez-Martín MA, McGovern SE, Marquardt CE, Roscioli JD, Ghosh S, Kerfeld CA, Beck WF. Fluorescence and Excited-State Conformational Dynamics of the Orange Carotenoid Protein. J Phys Chem B 2018; 122:1792-1800. [DOI: 10.1021/acs.jpcb.7b09435] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | | | | | | | | | | | - Cheryl A. Kerfeld
- Molecular
Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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18
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Greco JA, Wagner NL, Frank HA, Birge RR. The Forbidden 1 1B u– Excited Singlet State in Peridinin and Peridinin Analogues. J Phys Chem A 2018; 122:130-139. [DOI: 10.1021/acs.jpca.7b10001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jordan A. Greco
- Department of Chemistry, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269-3060, United States
| | - Nicole L. Wagner
- Department of Chemistry, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269-3060, United States
| | - Harry A. Frank
- Department of Chemistry, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269-3060, United States
| | - Robert R. Birge
- Department of Chemistry, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269-3060, United States
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19
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Roscioli JD, Ghosh S, LaFountain AM, Frank HA, Beck WF. Quantum Coherent Excitation Energy Transfer by Carotenoids in Photosynthetic Light Harvesting. J Phys Chem Lett 2017; 8:5141-5147. [PMID: 28968122 DOI: 10.1021/acs.jpclett.7b01791] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
It remains an open question whether quantum coherence and molecular excitons created by delocalization of electronic excited states are essential features of the mechanisms that enable efficient light capture and excitation energy transfer to reaction centers in photosynthetic organisms. The peridinin-chlorophyll a protein from marine dinoflagellates is an example of a light-harvesting system with tightly clustered antenna chromophores in which quantum coherence has long been suspected, but unusually it features the carotenoid peridinin as the principal light absorber for mid-visible photons. We report that broad-band two-dimensional electronic spectroscopy indeed reveals the initial presence of exciton relaxation pathways that enable transfer of excitation from peridinin to chlorophyll a in <20 fs, but the quantum coherence that permits this is very short-lived. Strongly coupled excited-state vibrational distortions of the peridinins trigger a dynamic transition of the electronic structure of the system and a rapid conversion to incoherent energy transfer mechanisms.
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Affiliation(s)
- Jerome D Roscioli
- Department of Chemistry, Michigan State University , East Lansing, Michigan 48824-1322, United States
| | - Soumen Ghosh
- Department of Chemistry, Michigan State University , East Lansing, Michigan 48824-1322, United States
| | - Amy M LaFountain
- Department of Chemistry, University of Connecticut , Storrs, Connecticut 06269-3036, United States
| | - Harry A Frank
- Department of Chemistry, University of Connecticut , Storrs, Connecticut 06269-3036, United States
| | - Warren F Beck
- Department of Chemistry, Michigan State University , East Lansing, Michigan 48824-1322, United States
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20
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Kowalewski M, Fingerhut BP, Dorfman KE, Bennett K, Mukamel S. Simulating Coherent Multidimensional Spectroscopy of Nonadiabatic Molecular Processes: From the Infrared to the X-ray Regime. Chem Rev 2017; 117:12165-12226. [DOI: 10.1021/acs.chemrev.7b00081] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Markus Kowalewski
- Department
of Chemistry and Department of Physics and Astronomy, University of California, Irvine, California 92697-2025, United States
| | - Benjamin P. Fingerhut
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, D-12489 Berlin, Germany
| | - Konstantin E. Dorfman
- State
Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Kochise Bennett
- Department
of Chemistry and Department of Physics and Astronomy, University of California, Irvine, California 92697-2025, United States
| | - Shaul Mukamel
- Department
of Chemistry and Department of Physics and Astronomy, University of California, Irvine, California 92697-2025, United States
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21
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Nairat M, Webb M, Esch MP, Lozovoy VV, Levine BG, Dantus M. Time-resolved signatures across the intramolecular response in substituted cyanine dyes. Phys Chem Chem Phys 2017; 19:14085-14095. [PMID: 28518192 DOI: 10.1039/c7cp00119c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The optically populated excited state wave packet propagates along multidimensional intramolecular coordinates soon after photoexcitation. This action occurs alongside an intermolecular response from the surrounding solvent. Disentangling the multidimensional convoluted signal enables the possibility to separate and understand the initial intramolecular relaxation pathways over the excited state potential energy surface. Here we track the initial excited state dynamics by measuring the fluorescence yield from the first excited state as a function of time delay between two color femtosecond pulses for several cyanine dyes having different substituents. We find that when the high frequency pulse precedes the low frequency one and for timescales up to 200 fs, the excited state population can be depleted through stimulated emission with efficiency that is dependent on the molecular electronic structure. A similar observation at even shorter times was made by scanning the chirp (frequencies ordering) of a femtosecond pulse. The changes in depletion reflect the rate at which the nuclear coordinates of the excited state leave the Franck-Condon (FC) region and progress towards achieving equilibrium. Through functional group substitution, we explore these dynamic changes as a function of dipolar change following photoexcitation. Density functional theory calculations were performed to provide greater insight into the experimental spectroscopic observations. Complete active space (CAS) self-consistent field and CAS second order perturbation theory calculated potential energy surfaces tracking twisting and pyramidalization confirm that the steeper potential at the FC region leads to the observation of faster wave packet dynamics.
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Affiliation(s)
- Muath Nairat
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA.
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22
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Ghosh S, Bishop MM, Roscioli JD, LaFountain AM, Frank HA, Beck WF. Excitation Energy Transfer by Coherent and Incoherent Mechanisms in the Peridinin-Chlorophyll a Protein. J Phys Chem Lett 2017; 8:463-469. [PMID: 28042923 DOI: 10.1021/acs.jpclett.6b02881] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Excitation energy transfer from peridinin to chlorophyll (Chl) a is unusually efficient in the peridinin-chlorophyll a protein (PCP) from dinoflagellates. This enhanced performance is derived from the long intrinsic lifetime of 4.4 ps for the S2 (11Bu+) state of peridinin in PCP, which arises from the electron-withdrawing properties of its carbonyl substituent. Results from heterodyne transient grating spectroscopy indicate that S2 serves as the donor for two channels of energy transfer: a 30 fs process involving quantum coherence and delocalized peridinin-Chl states and an incoherent, 2.5 ps process initiated by dynamic exciton localization, which accompanies the formation of a conformationally distorted intermediate in 45 fs. The lifetime of the S2 state is lengthened in PCP by its intramolecular charge-transfer character, which increases the system-bath coupling and slows the torsional motions that promote nonradiative decay to the S1 (21Ag-) state.
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Affiliation(s)
- Soumen Ghosh
- Department of Chemistry, Michigan State University , East Lansing, Michigan 48824-1322, United States
| | - Michael M Bishop
- Department of Chemistry, Michigan State University , East Lansing, Michigan 48824-1322, United States
| | - Jerome D Roscioli
- Department of Chemistry, Michigan State University , East Lansing, Michigan 48824-1322, United States
| | - Amy M LaFountain
- Department of Chemistry, University of Connecticut , Storrs, Connecticut 06269-3036, United States
| | - Harry A Frank
- Department of Chemistry, University of Connecticut , Storrs, Connecticut 06269-3036, United States
| | - Warren F Beck
- Department of Chemistry, Michigan State University , East Lansing, Michigan 48824-1322, United States
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