1
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Jing H, Magdaong NCM, Diers JR, Kirmaier C, Bocian DF, Holten D, Lindsey JS. Dyads with tunable near-infrared donor-acceptor excited-state energy gaps: molecular design and Förster analysis for ultrafast energy transfer. Phys Chem Chem Phys 2023; 25:1827-1847. [PMID: 36601996 DOI: 10.1039/d2cp04689j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Bacteriochlorophylls, nature's near-infrared absorbers, play an essential role in energy transfer in photosynthetic antennas and reaction centers. To probe energy-transfer processes akin to those in photosynthetic systems, nine synthetic bacteriochlorin-bacteriochlorin dyads have been prepared wherein the constituent pigments are joined at the meso-positions by a phenylethyne linker. The phenylethyne linker is an unsymmetric auxochrome, which differentially shifts the excited-state energies of the phenyl- or ethynyl-attached bacteriochlorin constituents in the dyad. Molecular designs utilized known effects of macrocycle substituents to engineer bacteriochlorins with S0 → S1 (Qy) transitions spanning 725-788 nm. The design-predicted donor-acceptor excited-state energy gaps in the dyads agree well with those obtained from time dependent density functional theory calculations and with the measured range of 197-1089 cm-1. Similar trends with donor-acceptor excited-state energy gaps are found for (1) the measured ultrafast energy-transfer rates of (0.3-1.7 ps)-1, (2) the spectral overlap integral (J) in Förster energy-transfer theory, and (3) donor-acceptor electronic mixing manifested in the natural transition orbitals for the S0 → S1 transition. Subtle outcomes include the near orthogonal orientation of the π-planes of the bacteriochlorin macrocycles, and the substituent-induced shift in transition-dipole moment from the typical coincidence with the NH-NH axis; the two features together afforded the Förster orientation term κ2 ranging from 0.55-1.53 across the nine dyads, a value supportive of efficient excited-state energy transfer. The molecular design and collective insights on the dyads are valuable for studies relevant to artificial photosynthesis and other processes requiring ultrafast energy transfer.
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Affiliation(s)
- Haoyu Jing
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, USA.
| | | | - James R Diers
- Department of Chemistry, University of California, Riverside, California 92521-0403, USA.
| | - Christine Kirmaier
- Department of Chemistry, Washington University, St. Louis, Missouri 63130-4889, USA.
| | - David F Bocian
- Department of Chemistry, University of California, Riverside, California 92521-0403, USA.
| | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, Missouri 63130-4889, USA.
| | - Jonathan S Lindsey
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, USA.
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2
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From antenna to reaction center: Pathways of ultrafast energy and charge transfer in photosystem II. Proc Natl Acad Sci U S A 2022; 119:e2208033119. [PMID: 36215463 PMCID: PMC9586314 DOI: 10.1073/pnas.2208033119] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The photosystem II core complex (PSII-CC) is a photosynthetic complex that contains antenna proteins, which collect energy from sunlight, and a reaction center, which converts the collected energy to redox potential. Understanding the interplay between the antenna proteins and the reaction center will facilitate the development of more efficient solar energy conversion technologies. Here, we study the sub-100-ps dynamics of PSII-CC with two-dimensional electronic-vibrational spectroscopy, which connects energy flows with physical space, allowing a direct mapping of energy transfer pathways. Our results reveal a complex dynamical scheme which includes a specific pathway that connects CP43 to the reaction center. Resolving this pathway experimentally provides insights into the energy conversion processes in natural photosynthesis. The photosystem II core complex (PSII-CC) is the smallest subunit of the oxygenic photosynthetic apparatus that contains core antennas and a reaction center, which together allow for rapid energy transfer and charge separation, ultimately leading to efficient solar energy conversion. However, there is a lack of consensus on the interplay between the energy transfer and charge separation dynamics of the core complex. Here, we report the application of two-dimensional electronic-vibrational (2DEV) spectroscopy to the spinach PSII-CC at 77 K. The simultaneous temporal and spectral resolution afforded by 2DEV spectroscopy facilitates the separation and direct assignment of coexisting dynamical processes. Our results show that the dominant dynamics of the PSII-CC are distinct in different excitation energy regions. By separating the excitation regions, we are able to distinguish the intraprotein dynamics and interprotein energy transfer. Additionally, with the improved resolution, we are able to identify the key pigments involved in the pathways, allowing for a direct connection between dynamical and structural information. Specifically, we show that C505 in CP43 and the peripheral chlorophyll ChlzD1 in the reaction center are most likely responsible for energy transfer from CP43 to the reaction center.
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3
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Magdaong NCM, Jing H, Diers JR, Kirmaier C, Lindsey JS, Bocian DF, Holten D. Probing the Effects of Electronic-Vibrational Resonance on the Rate of Excited-State Energy Transfer in Bacteriochlorin Dyads. J Phys Chem Lett 2022; 13:7906-7910. [PMID: 35980198 DOI: 10.1021/acs.jpclett.2c02154] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The impact of vibrational-electronic resonances on the rate of excited-state energy transfer is examined in a set of bacteriochlorin dyads that employ the same phenylethyne linker. The donor/acceptor excited-state energy gap is tuned from ∼200 to ∼1100 cm-1 using peripheral substituents on the donor and acceptor bacteriochlorin macrocycles. Ultrafast energy transfer is observed with rate constants of (0.3 ps)-1 to (1.7 ps)-1, which agree with those predicted by Förster theory to within a factor of 2. Furthermore, the measured rates follow a trend-line with only small deviations that do not correlate with the density of vibrations at the donor/acceptor excited-state energy gap. Thus, if vibrational-electronic resonances occur in any of these dyads, which seems likely, the impact on the rate of energy transfer is small.
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Affiliation(s)
- Nikki Cecil M Magdaong
- Department of Chemistry, Washington University, St. Louis, Missouri63130-4889, United States
| | - Haoyu Jing
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina27695-8204, United States
| | - James R Diers
- Department of Chemistry, University of California, Riverside, Riverside, California92521-0403, United States
| | - Christine Kirmaier
- Department of Chemistry, Washington University, St. Louis, Missouri63130-4889, United States
| | - Jonathan S Lindsey
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina27695-8204, United States
| | - David F Bocian
- Department of Chemistry, University of California, Riverside, Riverside, California92521-0403, United States
| | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, Missouri63130-4889, United States
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4
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Roy P, Kundu S, Valdiviezo J, Bullard G, Fletcher JT, Liu R, Yang SJ, Zhang P, Beratan DN, Therien MJ, Makri N, Fleming GR. Synthetic Control of Exciton Dynamics in Bioinspired Cofacial Porphyrin Dimers. J Am Chem Soc 2022; 144:6298-6310. [PMID: 35353523 PMCID: PMC9011348 DOI: 10.1021/jacs.1c12889] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Indexed: 11/29/2022]
Abstract
Understanding how the complex interplay among excitonic interactions, vibronic couplings, and reorganization energy determines coherence-enabled transport mechanisms is a grand challenge with both foundational implications and potential payoffs for energy science. We use a combined experimental and theoretical approach to show how a modest change in structure may be used to modify the exciton delocalization, tune electronic and vibrational coherences, and alter the mechanism of exciton transfer in covalently linked cofacial Zn-porphyrin dimers (meso-beta linked ABm-β and meso-meso linked AAm-m). While both ABm-β and AAm-m feature zinc porphyrins linked by a 1,2-phenylene bridge, differences in the interporphyrin connectivity set the lateral shift between macrocycles, reducing electronic coupling in ABm-β and resulting in a localized exciton. Pump-probe experiments show that the exciton dynamics is faster by almost an order of magnitude in the strongly coupled AAm-m dimer, and two-dimensional electronic spectroscopy (2DES) identifies a vibronic coherence that is absent in ABm-β. Theoretical studies indicate how the interchromophore interactions in these structures, and their system-bath couplings, influence excitonic delocalization and vibronic coherence-enabled rapid exciton transport dynamics. Real-time path integral calculations reproduce the exciton transfer kinetics observed experimentally and find that the linking-modulated exciton delocalization strongly enhances the contribution of vibronic coherences to the exciton transfer mechanism, and that this coherence accelerates the exciton transfer dynamics. These benchmark molecular design, 2DES, and theoretical studies provide a foundation for directed explorations of nonclassical effects on exciton dynamics in multiporphyrin assemblies.
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Affiliation(s)
- Partha
Pratim Roy
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Molecular
Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Kavli
Energy Nanoscience Institute at Berkeley, Berkeley, California 94720, United States
| | - Sohang Kundu
- Department
of Chemistry, University of Illinois, Urbana, Illinois 61801, United States
| | - Jesús Valdiviezo
- Department
of Chemistry, Duke University, Durham, North Carolina 27708, United States
- Department
of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, United States
| | - George Bullard
- Department
of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - James T. Fletcher
- Department
of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Rui Liu
- Department
of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Shiun-Jr Yang
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Molecular
Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Peng Zhang
- Department
of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - David N. Beratan
- Department
of Chemistry, Duke University, Durham, North Carolina 27708, United States
- Department
of Physics, Duke University, Durham, North Carolina 27708, United States
- Department
of Biochemistry, Duke University, Durham, North Carolina 27710, United States
| | - Michael J. Therien
- Department
of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Nancy Makri
- Department
of Chemistry, University of Illinois, Urbana, Illinois 61801, United States
- Department
of Physics, University of Illinois, Urbana, Illinois 61801, United States
- Illinois
Quantum Information Science & Technology Center, University of Illinois, Urbana, Illinois 61801, United States
| | - Graham R. Fleming
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Molecular
Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Kavli
Energy Nanoscience Institute at Berkeley, Berkeley, California 94720, United States
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5
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Ma F, Romero E, Jones MR, Novoderezhkin VI, Yu LJ, van Grondelle R. Dynamics of diverse coherences in primary charge separation of bacterial reaction center at 77 K revealed by wavelet analysis. PHOTOSYNTHESIS RESEARCH 2022; 151:225-234. [PMID: 34709567 DOI: 10.1007/s11120-021-00881-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 10/01/2021] [Indexed: 06/13/2023]
Abstract
To uncover the mechanism behind the high photo-electronic conversion efficiency in natural photosynthetic complexes it is essential to trace the dynamics of electronic and vibrational quantum coherences. Here we apply wavelet analysis to two-dimensional electronic spectroscopy data for three purple bacterial reaction centers with mutations that produce drastically different rates of primary charge separation. From the frequency distribution and dynamic evolution features of the quantum beating, electronic coherence with a dephasing lifetime of ~50 fs, vibronic coherence with a lifetime of ~150 fs and vibrational/vibronic coherences with a lifetime of 450 fs are distinguished. We find that they are responsible for, or couple to, different specific steps during the primary charge separation process, i.e., intradimer charge transfer inside the special bacteriochlorophyll pair followed by its relaxation and stabilization of the charge-transfer state. The results enlighten our understanding of how quantum coherences participate in, and contribute to, a biological electron transfer reaction.
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Affiliation(s)
- Fei Ma
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Nanxincun 20, Xiangshan, Beijing, 100093, China.
- Department of Biophysics, Faculty of Sciences, VU University Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands.
| | - Elisabet Romero
- Department of Biophysics, Faculty of Sciences, VU University Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
- Institute of Chemical Research of Catalonia, Barcelona Institute of Science and Technology, E-43007, Tarragona, Spain
| | - Michael R Jones
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK
| | - Vladimir I Novoderezhkin
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Leninskie Gory, Moscow, Russia, 119992
| | - Long-Jiang Yu
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Nanxincun 20, Xiangshan, Beijing, 100093, China.
| | - Rienk van Grondelle
- Department of Biophysics, Faculty of Sciences, VU University Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
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6
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Biswas S, Kim J, Zhang X, Scholes GD. Coherent Two-Dimensional and Broadband Electronic Spectroscopies. Chem Rev 2022; 122:4257-4321. [PMID: 35037757 DOI: 10.1021/acs.chemrev.1c00623] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Over the past few decades, coherent broadband spectroscopy has been widely used to improve our understanding of ultrafast processes (e.g., photoinduced electron transfer, proton transfer, and proton-coupled electron transfer reactions) at femtosecond resolution. The advances in femtosecond laser technology along with the development of nonlinear multidimensional spectroscopy enabled further insights into ultrafast energy transfer and carrier relaxation processes in complex biological and material systems. New discoveries and interpretations have led to improved design principles for optimizing the photophysical properties of various artificial systems. In this review, we first provide a detailed theoretical framework of both coherent broadband and two-dimensional electronic spectroscopy (2DES). We then discuss a selection of experimental approaches and considerations of 2DES along with best practices for data processing and analysis. Finally, we review several examples where coherent broadband and 2DES were employed to reveal mechanisms of photoinitiated ultrafast processes in molecular, biological, and material systems. We end the review with a brief perspective on the future of the experimental techniques themselves and their potential to answer an even greater range of scientific questions.
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Affiliation(s)
- Somnath Biswas
- Department of Chemistry, Princeton University, Princeton, New Jersey 08 544, United States
| | - JunWoo Kim
- Department of Chemistry, Princeton University, Princeton, New Jersey 08 544, United States
| | - Xinzi Zhang
- Department of Chemistry, Princeton University, Princeton, New Jersey 08 544, United States
| | - Gregory D Scholes
- Department of Chemistry, Princeton University, Princeton, New Jersey 08 544, United States
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7
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Policht VR, Niedringhaus A, Willow R, Laible PD, Bocian DF, Kirmaier C, Holten D, Mančal T, Ogilvie JP. Hidden vibronic and excitonic structure and vibronic coherence transfer in the bacterial reaction center. SCIENCE ADVANCES 2022; 8:eabk0953. [PMID: 34985947 PMCID: PMC8730630 DOI: 10.1126/sciadv.abk0953] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
We report two-dimensional electronic spectroscopy (2DES) experiments on the bacterial reaction center (BRC) from purple bacteria, revealing hidden vibronic and excitonic structure. Through analysis of the coherent dynamics of the BRC, we identify multiple quasi-resonances between pigment vibrations and excitonic energy gaps, and vibronic coherence transfer processes that are typically neglected in standard models of photosynthetic energy transfer and charge separation. We support our assignment with control experiments on bacteriochlorophyll and simulations of the coherent dynamics using a reduced excitonic model of the BRC. We find that specific vibronic coherence processes can readily reveal weak exciton transitions. While the functional relevance of such processes is unclear, they provide a spectroscopic tool that uses vibrations as a window for observing excited state structure and dynamics elsewhere in the BRC via vibronic coupling. Vibronic coherence transfer reveals the upper exciton of the “special pair” that was weakly visible in previous 2DES experiments.
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Affiliation(s)
- Veronica R. Policht
- Department of Physics, University of Michigan, 450 Church St, Ann Arbor, MI 48109, USA
| | - Andrew Niedringhaus
- Department of Physics, University of Michigan, 450 Church St, Ann Arbor, MI 48109, USA
| | - Rhiannon Willow
- Department of Physics, University of Michigan, 450 Church St, Ann Arbor, MI 48109, USA
| | - Philip D. Laible
- Biosciences Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - David F. Bocian
- Department of Chemistry, University of California, Riverside, CA 92521, USA
| | - Christine Kirmaier
- Department of Chemistry, Washington University, St. Louis, MO 63130, USA
| | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, MO 63130, USA
| | - Tomáš Mančal
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, CZ-12116 Prague 2, Czech Republic
| | - Jennifer P. Ogilvie
- Department of Physics, University of Michigan, 450 Church St, Ann Arbor, MI 48109, USA
- Corresponding author.
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8
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Bubilaitis V, Rancova O, Abramavicius D. Vibration-mediated energy transport in bacterial reaction center: Simulation study. J Chem Phys 2021; 154:214115. [PMID: 34240965 DOI: 10.1063/5.0048815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Exciton energy relaxation in a bacterial Reaction Center (bRC) pigment-protein aggregate presumably involves emission of high energy vibrational quanta to cover wide energy gaps between excitons. Here, we assess this hypothesis utilizing vibronic two-particle theory in modeling of the excitation relaxation process in bRC. Specific high frequency molecular vibrational modes are included explicitly one at a time in order to check which high frequency vibrations are involved in the excitation relaxation process. The low frequency bath modes are treated perturbatively within Redfield relaxation theory. The analysis of the population relaxation rate data indicates energy flow pathways in bRC and suggests that specific vibrations may be responsible for the excitation relaxation process.
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Affiliation(s)
- Vytautas Bubilaitis
- Institute of Chemical Physics, Vilnius University, Sauletekio al. 9-III, Vilnius 10222, Lithuania
| | - Olga Rancova
- Institute of Chemical Physics, Vilnius University, Sauletekio al. 9-III, Vilnius 10222, Lithuania
| | - Darius Abramavicius
- Institute of Chemical Physics, Vilnius University, Sauletekio al. 9-III, Vilnius 10222, Lithuania
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9
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Sahu A, Kurian JS, Tiwari V. Vibronic resonance is inadequately described by one-particle basis sets. J Chem Phys 2020; 153:224114. [DOI: 10.1063/5.0029027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Affiliation(s)
- Amitav Sahu
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - Jo Sony Kurian
- Department of Chemistry, Indian Institute of Science Education and Research, Bhopal, Madhya Pradesh 462066, India
| | - Vivek Tiwari
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, Karnataka 560012, India
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10
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Lim J, Bösen CM, Somoza AD, Koch CP, Plenio MB, Huelga SF. Multicolor Quantum Control for Suppressing Ground State Coherences in Two-Dimensional Electronic Spectroscopy. PHYSICAL REVIEW LETTERS 2019; 123:233201. [PMID: 31868446 DOI: 10.1103/physrevlett.123.233201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Indexed: 06/10/2023]
Abstract
The measured multidimensional spectral response of different light harvesting complexes exhibits oscillatory features which suggest an underlying coherent energy transfer. However, making this inference rigorous is challenging due to the difficulty of isolating excited state coherences in highly congested spectra. In this work, we provide a coherent control scheme that suppresses ground state coherences, thus making rephasing spectra dominated by excited state coherences. We provide a benchmark for the scheme using a model dimeric system and numerically exact methods to analyze the spectral response. We argue that combining temporal and spectral control methods can facilitate a second generation of experiments that are tailored to extract desired information and thus significantly advance our understanding of complex open many-body structure and dynamics.
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Affiliation(s)
- J Lim
- Institut für Theoretische Physik and IQST, Albert-Einstein-Allee 11, Universität Ulm, 89081 Ulm, Germany
| | - C M Bösen
- Institut für Theoretische Physik and IQST, Albert-Einstein-Allee 11, Universität Ulm, 89081 Ulm, Germany
| | - A D Somoza
- Institut für Theoretische Physik and IQST, Albert-Einstein-Allee 11, Universität Ulm, 89081 Ulm, Germany
| | - C P Koch
- Theoretische Physik, Universität Kassel, Heinrich-Plett-Strasse 40, 34132 Kassel, Germany
| | - M B Plenio
- Institut für Theoretische Physik and IQST, Albert-Einstein-Allee 11, Universität Ulm, 89081 Ulm, Germany
| | - S F Huelga
- Institut für Theoretische Physik and IQST, Albert-Einstein-Allee 11, Universität Ulm, 89081 Ulm, Germany
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11
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Paleček D, Edlund P, Gustavsson E, Westenhoff S, Zigmantas D. Potential pitfalls of the early-time dynamics in two-dimensional electronic spectroscopy. J Chem Phys 2019; 151:024201. [DOI: 10.1063/1.5079817] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- David Paleček
- Department of Chemical Physics, Lund University, P.O. Box 124, SE-22100 Lund, Sweden
- Department of Chemical Physics, Charles University in Prague, Ke Karlovu 3, 121 16 Praha 2, Czech Republic
| | - Petra Edlund
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE-40530 Gothenburg, Sweden
| | - Emil Gustavsson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE-40530 Gothenburg, Sweden
| | - Sebastian Westenhoff
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE-40530 Gothenburg, Sweden
| | - Donatas Zigmantas
- Department of Chemical Physics, Lund University, P.O. Box 124, SE-22100 Lund, Sweden
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12
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Wang L, Allodi MA, Engel GS. Quantum coherences reveal excited-state dynamics in biophysical systems. Nat Rev Chem 2019. [DOI: 10.1038/s41570-019-0109-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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13
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Ma F, Romero E, Jones MR, Novoderezhkin VI, van Grondelle R. Both electronic and vibrational coherences are involved in primary electron transfer in bacterial reaction center. Nat Commun 2019; 10:933. [PMID: 30804346 PMCID: PMC6389996 DOI: 10.1038/s41467-019-08751-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 01/15/2019] [Indexed: 11/09/2022] Open
Abstract
Understanding the mechanism behind the near-unity efficiency of primary electron transfer in reaction centers is essential for designing performance-enhanced artificial solar conversion systems to fulfill mankind’s growing demands for energy. One of the most important challenges is distinguishing electronic and vibrational coherence and establishing their respective roles during charge separation. In this work we apply two-dimensional electronic spectroscopy to three structurally-modified reaction centers from the purple bacterium Rhodobacter sphaeroides with different primary electron transfer rates. By comparing dynamics and quantum beats, we reveal that an electronic coherence with dephasing lifetime of ~190 fs connects the initial excited state, P*, and the charge-transfer intermediate \documentclass[12pt]{minimal}
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\begin{document}$${\mathrm{P}}_{\mathrm{A}}^ + {\mathrm{P}}_{\mathrm{B}}^ -$$\end{document}PA+PB-; this \documentclass[12pt]{minimal}
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\begin{document}$${\mathrm{P}}^ \ast \to {\mathrm{P}}_{\mathrm{A}}^ + {\mathrm{P}}_{\mathrm{B}}^ -$$\end{document}P*→PA+PB- step is associated with a long-lived quasi-resonant vibrational coherence; and another vibrational coherence is associated with stabilizing the primary photoproduct, \documentclass[12pt]{minimal}
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\begin{document}$${\mathrm{P}}^ + {\mathrm{B}}_{\mathrm{A}}^ -$$\end{document}P+BA-. The results show that both electronic and vibrational coherences are involved in primary electron transfer process and they correlate with the super-high efficiency. Distinguishing electronic and vibrational coherences helps to clarify the near-unity efficiency of primary electron transfer in reaction centres. Here, the authors report their respective correlation with the electron transfer rate by comparing the 2D electronic spectra of three mutant reaction centres.
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Affiliation(s)
- Fei Ma
- Department of Biophysics, Faculty of Sciences, VU University Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands.
| | - Elisabet Romero
- Department of Biophysics, Faculty of Sciences, VU University Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
| | - Michael R Jones
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK
| | - Vladimir I Novoderezhkin
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Leninskie Gory, Moscow, 119992, Russia
| | - Rienk van Grondelle
- Department of Biophysics, Faculty of Sciences, VU University Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
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14
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Paleček D, Zigmantas D. Double-crossed polarization transient grating for distinction and characterization of coherences. OPTICS EXPRESS 2018; 26:32900-32907. [PMID: 30645450 DOI: 10.1364/oe.26.032900] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 08/28/2018] [Indexed: 06/09/2023]
Abstract
Coherent phenomena have been widely suggested to play a role in efficient photosynthetic light harvesting and charge separation processes. To substantiate these ideas, separation of intramolecular vibrational coherences from purely electronic or mixed vibronic coherences is essential. To this end, polarization-controlled two-dimensional electronic spectroscopy has been shown to provide an effective selectivity. We show that analogous discrimination can be achieved in a transient grating experiment by employing the double-crossed polarization scheme. This is demonstrated in a study of bacterial reaction centers. Significantly faster acquisition times of these experiments make longer population time scans feasible, thereby achieving improved frequency resolution and allowing for accurate extraction of coherence frequencies and dephasing times. These parameters are crucial for the discussion on relevance of the measured coherences to energy or electron transfer phenomena.
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15
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Policht VR, Niedringhaus A, Ogilvie JP. Characterization of Vibrational Coherence in Monomeric Bacteriochlorophyll a by Two-Dimensional Electronic Spectroscopy. J Phys Chem Lett 2018; 9:6631-6637. [PMID: 30376340 DOI: 10.1021/acs.jpclett.8b02691] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Bacteriochlorophyll a (BChla) is the most abundant pigment found in the Bacterial Reaction Center (BRC) and light-harvesting proteins of photosynthetic purple and green bacteria. Recent two-dimensional electronic spectroscopy (2DES) studies of photosynthetic pigment-protein complexes including the BRC and the Fenna-Matthews-Olson (FMO) complex have shown oscillatory signals, or coherences, whose physical origin has been hotly debated. To better understand the observations of coherence in larger photosynthetic systems, it is important to carefully characterize the spectroscopic signatures of the monomeric pigments. Prior spectroscopic studies of BChla have differed significantly in their observations, with some studies reporting little to no coherence. Here we present evidence of strong coherences in monomeric BChla in isopropanol using 2DES at 77 K. We resolve many modes with frequencies that correspond well with known vibrational modes. We confirm their vibrational origin by comparing the 2D spectroscopic signatures with expectations based on a purely vibrational model.
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Affiliation(s)
- Veronica R Policht
- Department of Physics , University of Michigan , Ann Arbor , Michigan 48108 , United States
| | - Andrew Niedringhaus
- Department of Physics , University of Michigan , Ann Arbor , Michigan 48108 , United States
| | - Jennifer P Ogilvie
- Department of Physics , University of Michigan , Ann Arbor , Michigan 48108 , United States
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16
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Jonas DM. Vibrational and Nonadiabatic Coherence in 2D Electronic Spectroscopy, the Jahn–Teller Effect, and Energy Transfer. Annu Rev Phys Chem 2018; 69:327-352. [DOI: 10.1146/annurev-physchem-052516-050602] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- David M. Jonas
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, USA
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17
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Primary processes in the bacterial reaction center probed by two-dimensional electronic spectroscopy. Proc Natl Acad Sci U S A 2018; 115:3563-3568. [PMID: 29555738 DOI: 10.1073/pnas.1721927115] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
In the initial steps of photosynthesis, reaction centers convert solar energy to stable charge-separated states with near-unity quantum efficiency. The reaction center from purple bacteria remains an important model system for probing the structure-function relationship and understanding mechanisms of photosynthetic charge separation. Here we perform 2D electronic spectroscopy (2DES) on bacterial reaction centers (BRCs) from two mutants of the purple bacterium Rhodobacter capsulatus, spanning the Q y absorption bands of the BRC. We analyze the 2DES data using a multiexcitation global-fitting approach that employs a common set of basis spectra for all excitation frequencies, incorporating inputs from the linear absorption spectrum and the BRC structure. We extract the exciton energies, resolving the previously hidden upper exciton state of the special pair. We show that the time-dependent 2DES data are well-represented by a two-step sequential reaction scheme in which charge separation proceeds from the excited state of the special pair (P*) to P+HA- via the intermediate P+BA- When inhomogeneous broadening and Stark shifts of the B* band are taken into account we can adequately describe the 2DES data without the need to introduce a second charge-separation pathway originating from the excited state of the monomeric bacteriochlorophyll BA*.
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18
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Rancova O, Jankowiak R, Abramavicius D. Role of Bath Fluctuations in the Double-Excitation Manifold in Shaping the 2DES of Bacterial Reaction Centers at Low Temperature. J Phys Chem B 2018; 122:1348-1366. [DOI: 10.1021/acs.jpcb.7b08905] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Olga Rancova
- Institute
of Chemical Physics, Vilnius University, Sauletekio al 9-III, 10222 Vilnius, Lithuania
| | - Ryszard Jankowiak
- Department
of Chemistry and Department of Physics, Kansas State University, 213 CBC Building, Manhattan, Kansas 66506-0401, United States
| | - Darius Abramavicius
- Institute
of Chemical Physics, Vilnius University, Sauletekio al 9-III, 10222 Vilnius, Lithuania
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19
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Tiwari V, Peters WK, Jonas DM. Electronic energy transfer through non-adiabatic vibrational-electronic resonance. I. Theory for a dimer. J Chem Phys 2017; 147:154308. [DOI: 10.1063/1.5005835] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Vivek Tiwari
- Department of Chemistry and Biochemistry, University of Colorado, 215 UCB, Boulder, Colorado 80309, USA
| | - William K. Peters
- Department of Chemistry and Biochemistry, University of Colorado, 215 UCB, Boulder, Colorado 80309, USA
| | - David M. Jonas
- Department of Chemistry and Biochemistry, University of Colorado, 215 UCB, Boulder, Colorado 80309, USA
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20
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Paleček D, Edlund P, Westenhoff S, Zigmantas D. Quantum coherence as a witness of vibronically hot energy transfer in bacterial reaction center. SCIENCE ADVANCES 2017; 3:e1603141. [PMID: 28913419 PMCID: PMC5587020 DOI: 10.1126/sciadv.1603141] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 08/08/2017] [Indexed: 05/25/2023]
Abstract
Photosynthetic proteins have evolved over billions of years so as to undergo optimal energy transfer to the sites of charge separation. On the basis of spectroscopically detected quantum coherences, it has been suggested that this energy transfer is partially wavelike. This conclusion depends critically on the assignment of the coherences to the evolution of excitonic superpositions. We demonstrate that, for a bacterial reaction center protein, long-lived coherent spectroscopic oscillations, which bear canonical signatures of excitonic superpositions, are essentially vibrational excited-state coherences shifted to the ground state of the chromophores. We show that the appearance of these coherences arises from a release of electronic energy during energy transfer. Our results establish how energy migrates on vibrationally hot chromophores in the reaction center, and they call for a reexamination of claims of quantum energy transfer in photosynthesis.
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Affiliation(s)
- David Paleček
- Department of Chemical Physics, Lund University, Box 124, SE-22100 Lund, Sweden
- Department of Chemical Physics, Charles University, Ke Karlovu 3, CZ-121 16 Praha 2, Czech Republic
| | - Petra Edlund
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE-40530 Gothenburg, Sweden
| | - Sebastian Westenhoff
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE-40530 Gothenburg, Sweden
| | - Donatas Zigmantas
- Department of Chemical Physics, Lund University, Box 124, SE-22100 Lund, Sweden
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21
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Tsargorodska A, Cartron ML, Vasilev C, Kodali G, Mass OA, Baumberg JJ, Dutton PL, Hunter CN, Törmä P, Leggett GJ. Strong Coupling of Localized Surface Plasmons to Excitons in Light-Harvesting Complexes. NANO LETTERS 2016; 16:6850-6856. [PMID: 27689237 PMCID: PMC5135229 DOI: 10.1021/acs.nanolett.6b02661] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 09/28/2016] [Indexed: 05/24/2023]
Abstract
Gold nanostructure arrays exhibit surface plasmon resonances that split after attaching light harvesting complexes 1 and 2 (LH1 and LH2) from purple bacteria. The splitting is attributed to strong coupling between the localized surface plasmon resonances and excitons in the light-harvesting complexes. Wild-type and mutant LH1 and LH2 from Rhodobacter sphaeroides containing different carotenoids yield different splitting energies, demonstrating that the coupling mechanism is sensitive to the electronic states in the light harvesting complexes. Plasmon-exciton coupling models reveal different coupling strengths depending on the molecular organization and the protein coverage, consistent with strong coupling. Strong coupling was also observed for self-assembling polypeptide maquettes that contain only chlorins. However, it is not observed for monolayers of bacteriochlorophyll, indicating that strong plasmon-exciton coupling is sensitive to the specific presentation of the pigment molecules.
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Affiliation(s)
- Anna Tsargorodska
- Department
of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, U.K.
| | - Michaël L. Cartron
- Department
of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield S10 2TN, U.K.
| | - Cvetelin Vasilev
- Department
of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield S10 2TN, U.K.
| | - Goutham Kodali
- The
Johnson Research Foundation and Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 10104, United States
| | - Olga A. Mass
- Department
of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Jeremy J. Baumberg
- Cavendish
Laboratory, Dept. of Physics, University
of Cambridge, J. J. Thomson
Ave, Cambridge, CB3 0HE, U.K.
| | - P. Leslie Dutton
- The
Johnson Research Foundation and Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 10104, United States
| | - C. Neil Hunter
- Department
of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield S10 2TN, U.K.
| | - Päivi Törmä
- COMP Centre
of Excellence, Department of Applied Physics, Aalto University, School of Science,
P.O. Box 15100, 00076 Aalto, Finland
| | - Graham J. Leggett
- Department
of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, U.K.
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22
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Rather SR, Scholes GD. Slow Intramolecular Vibrational Relaxation Leads to Long-Lived Excited-State Wavepackets. J Phys Chem A 2016; 120:6792-9. [PMID: 27510098 DOI: 10.1021/acs.jpca.6b07796] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Broadband optical pump and compressed white light continuum probe were used to measure the transient excited-state absorption, ground-state bleach, and stimulated emission signals of cresyl violet solution in methanol. Amplitude oscillations caused by wavepacket motion in the ground and excited electronic states were analyzed. It was found that vibrational coherences in the excited state persist for more than the experimental waiting time window of 6 ps, and the strongest mode had a dephasing time constant of 2.4 ps. We hypothesize the dephasing of the wavepacket in the excited state is predominantly caused by intramolecular vibrational relaxation (IVR). Slow IVR indicates weak mode-mode coupling and therefore weak anharmonicity of the potential of this vibration. Thus, the initially prepared vibrational wavepacket in the excited state is not significantly perturbed by nonadiabatic coupling to other electronic states, and hence the diabatic and adiabatic representations of the system are essentially identical within the Born-Oppenheimer approximation. The wavepacket therefore evolves with time in an almost harmonic potential, slowly dephased by IVR and the pure vibrational decoherence. The consistency in the position of node (phase change in the wavepacket) in the excited-state absorption and stimulated emission signals without undergoing any frequency shift until the wavepacket is completely dephased conforms to the absence of any reactive internal conversion.
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Affiliation(s)
- Shahnawaz R. Rather
- Frick Chemistry Laboratory, Princeton University , Princeton, New Jersey 08544, United States
| | - Gregory D Scholes
- Frick Chemistry Laboratory, Princeton University , Princeton, New Jersey 08544, United States
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23
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Jankowiak R, Rancova O, Chen J, Kell A, Saer RG, Beatty JT, Abramavicius D. Mutation-Induced Changes in the Protein Environment and Site Energies in the (M)L214G Mutant of the Rhodobacter sphaeroides Bacterial Reaction Center. J Phys Chem B 2016; 120:7859-71. [PMID: 27458891 DOI: 10.1021/acs.jpcb.6b06151] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This work focuses on the low-temperature (5 K) photochemical (transient) hole-burned (HB) spectra within the P870 absorption band, and their theoretical analysis, for the (M)L214G mutant of the photosynthetic Rhodobacter sphaeroides bacterial reaction center (bRC). To provide insight into system-bath interactions of the bacteriochlorophyll a (BChl a) special pair, i.e., P870, in the mutated bRC, the optical line shape function for the P870 band is calculated numerically. On the basis of the modeling studies, we demonstrate that (M)L214G mutation leads to a heterogeneous population of bRCs with modified (increased) total electron-phonon coupling strength of the special pair BChl a and larger inhomogeneous broadening. Specifically, we show that after mutation in the (M)L214G bRC a large fraction (∼50%) of the bacteriopheophytin (HA) chromophores shifts red and the 800 nm absorption band broadens, while the remaining fraction of HA cofactors retains nearly the same site energy as HA in the wild-type bRC. Modeling using these two subpopulations allowed for fits of the absorption and nonresonant (transient) HB spectra of the mutant bRC in the charge neutral, oxidized, and charge-separated states using the Frenkel exciton Hamiltonian, providing new insight into the mutant's complex electronic structure. Although the average (M)L214G mutant quantum efficiency of P(+)QA(-) state formation seems to be altered in comparison with the wild-type bRC, the average electron transfer time (measured via resonant transient HB spectra within the P870 band) was not affected. Thus, mutation in the vicinity of the electron acceptor (HA) does not tune the charge separation dynamics. Finally, quenching of the (M)L214G mutant excited states by P(+) is addressed by persistent HB spectra burned within the B band in chemically oxidized samples.
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Affiliation(s)
| | - Olga Rancova
- Department of Theoretical Physics, Vilnius University , 10222 Vilnius, Lithuania
| | | | | | - Rafael G Saer
- Department of Microbiology and Immunology, University of British Columbia , Vancouver, BC V6T 1Z3, Canada
| | - J Thomas Beatty
- Department of Microbiology and Immunology, University of British Columbia , Vancouver, BC V6T 1Z3, Canada
| | - Darius Abramavicius
- Department of Theoretical Physics, Vilnius University , 10222 Vilnius, Lithuania
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24
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Iles-Smith J, Dijkstra AG, Lambert N, Nazir A. Energy transfer in structured and unstructured environments: Master equations beyond the Born-Markov approximations. J Chem Phys 2016; 144:044110. [DOI: 10.1063/1.4940218] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Affiliation(s)
- Jake Iles-Smith
- Controlled Quantum Dynamics Theory, Imperial College London, London SW7 2PG, United Kingdom
- Photon Science Institute and School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
- Department of Photonics Engineering, DTU Fotonik, Ørsteds Plads, 2800 Kongens Lyngby, Denmark
| | - Arend G. Dijkstra
- Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761 Hamburg, Germany
| | | | - Ahsan Nazir
- Photon Science Institute and School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
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25
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Butkus V, Dong H, Fleming GR, Abramavicius D, Valkunas L. Disorder-Induced Quantum Beats in Two-Dimensional Spectra of Excitonically Coupled Molecules. J Phys Chem Lett 2016; 7:277-282. [PMID: 26720834 DOI: 10.1021/acs.jpclett.5b02642] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Quantum superposition of molecular electronic states is very fragile because of thermal energy fluctuations and the static conformational disorder induced by the intimate surrounding of constituent molecules of the system. However, the nature of the long-lived quantum beats, observed in time-resolved spectra of molecular aggregates at physiological conditions, is still being debated. We present our study of the conditions when long-lived electronic quantum coherences originating from recently proposed inhomogeneous broadening mechanism are enhanced and reflected in the two-dimensional electronic spectra of the excitonically coupled molecular dimer. We show that depending on the amount of inhomogeneous broadening, the excitonically coupled molecular system can establish long-lived electronic coherences, caused by a disordered subensemble, for which the dephasing due to static energy disorder becomes significantly reduced. On the basis of these considerations, we present explanations for why the electronic or vibrational coherences were or were not observed in a range of recent experiments.
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Affiliation(s)
- Vytautas Butkus
- Department of Theoretical Physics, Faculty of Physics, Vilnius University , Sauletekio 9-III, 10222 Vilnius, Lithuania
- Center for Physical Sciences and Technology, Gostauto 9, 01108 Vilnius, Lithuania
| | - Hui Dong
- Department of Chemistry, University of California , Berkeley, California 94720, United States
- Physical Biosciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Graham R Fleming
- Department of Chemistry, University of California , Berkeley, California 94720, United States
- Physical Biosciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Darius Abramavicius
- Department of Theoretical Physics, Faculty of Physics, Vilnius University , Sauletekio 9-III, 10222 Vilnius, Lithuania
| | - Leonas Valkunas
- Department of Theoretical Physics, Faculty of Physics, Vilnius University , Sauletekio 9-III, 10222 Vilnius, Lithuania
- Center for Physical Sciences and Technology, Gostauto 9, 01108 Vilnius, Lithuania
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26
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Abramavicius D, Valkunas L. Role of coherent vibrations in energy transfer and conversion in photosynthetic pigment-protein complexes. PHOTOSYNTHESIS RESEARCH 2016; 127:33-47. [PMID: 25618783 DOI: 10.1007/s11120-015-0080-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 01/05/2015] [Indexed: 06/04/2023]
Abstract
Oscillatory features of two-dimensional spectra of photosynthetic pigment-protein complexes during few picoseconds after electronic excitations of chlorophylls in various pigment-proteins were recently related to the coherent nuclear vibrations. It has been also speculated that the vibrations may assist the excitonic energy transfer and charge separation, hence contributing to energy transport and energy conversion efficiency. Here, we consider three theoretical approaches usually used for characterization of the excitation dynamics and charge separation, namely Redfield, Förster, and Marcus model descriptions, regarding this question. We show that two out of the three mechanisms require explicit resonances of excitonic splittings and the nuclear vibration frequencies. However, the third one related to the electron transfer is in principle off resonant.
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Affiliation(s)
- Darius Abramavicius
- Department of Theoretical Physics, Vilnius University, Sauletekio al. 9-III, 10222, Vilnius, Lithuania.
| | - Leonas Valkunas
- Department of Theoretical Physics, Vilnius University, Sauletekio al. 9-III, 10222, Vilnius, Lithuania.
- Center for Physical Sciences and Technology, A. Gostauto 11, 01108, Vilnius, Lithuania.
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27
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Flanagan ML, Long PD, Dahlberg PD, Rolczynski BS, Massey SC, Engel GS. Mutations to R. sphaeroides Reaction Center Perturb Energy Levels and Vibronic Coupling but Not Observed Energy Transfer Rates. J Phys Chem A 2015; 120:1479-87. [PMID: 26630123 DOI: 10.1021/acs.jpca.5b08366] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The bacterial reaction center is capable of both efficiently collecting and quickly transferring energy within the complex; therefore, the reaction center serves as a convenient model for both energy transfer and charge separation. To spectroscopically probe the interactions between the electronic excited states on the chromophores and their intricate relationship with vibrational motions in their environment, we examine coherences between the excited states. Here, we investigate this question by introducing a series of point mutations within 12 Å of the special pair of bacteriochlorophylls in the Rhodobacter sphaeroides reaction center. Using two-dimensional spectroscopy, we find that the time scales of energy transfer dynamics remain unperturbed by these mutations. However, within these spectra, we detect changes in the mixed vibrational-electronic coherences in these reaction centers. Our results indicate that resonance between bacteriochlorophyll vibrational modes and excitonic energy gaps promote electronic coherences and support current vibronic models of photosynthetic energy transfer.
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Affiliation(s)
| | | | | | - Brian S Rolczynski
- Department of Chemistry, The James Franck Institute and The Institute for Biophysical Dynamics, The University of Chicago , Chicago, Illinois 60637, United States
| | - Sara C Massey
- Department of Chemistry, The James Franck Institute and The Institute for Biophysical Dynamics, The University of Chicago , Chicago, Illinois 60637, United States
| | - Gregory S Engel
- Department of Chemistry, The James Franck Institute and The Institute for Biophysical Dynamics, The University of Chicago , Chicago, Illinois 60637, United States
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28
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Novelli F, Nazir A, Richards GH, Roozbeh A, Wilk KE, Curmi PMG, Davis JA. Vibronic resonances facilitate excited-state coherence in light-harvesting proteins at room temperature. J Phys Chem Lett 2015; 6:4573-4580. [PMID: 26528956 DOI: 10.1021/acs.jpclett.5b02058] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Until recently it was believed that photosynthesis, a fundamental process for life on earth, could be fully understood with semiclassical models. However, puzzling quantum phenomena have been observed in several photosynthetic pigment-protein complexes, prompting questions regarding the nature and role of these effects. Recent attention has focused on discrete vibrational modes that are resonant or quasi-resonant with excitonic energy splittings and strongly coupled to these excitonic states. Here we unambiguously identify excited state coherent superpositions in photosynthetic light-harvesting complexes using a new experimental approach. Decoherence on the time scale of the excited state lifetime allows low energy (56 cm(-1)) oscillations on the signal intensity to be observed. In conjunction with an appropriate model, these oscillations provide clear and direct experimental evidence that the persistent coherences observed originate from quantum superpositions among vibronic excited states.
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Affiliation(s)
- Fabio Novelli
- Centre for Quantum and Optical Science, Swinburne University of Technology , Victoria 3122, Australia
| | - Ahsan Nazir
- Photon Science Institute and School of Physics & Astronomy, The University of Manchester , Oxford Road, Manchester, M13 9PL, United Kingdom
| | - Gethin H Richards
- Centre for Quantum and Optical Science, Swinburne University of Technology , Victoria 3122, Australia
| | - Ashkan Roozbeh
- Centre for Quantum and Optical Science, Swinburne University of Technology , Victoria 3122, Australia
| | - Krystyna E Wilk
- School of Physics, The University of New South Wales , Sydney, New South Wales 2052, Australia
| | - Paul M G Curmi
- School of Physics, The University of New South Wales , Sydney, New South Wales 2052, Australia
| | - Jeffrey A Davis
- Centre for Quantum and Optical Science, Swinburne University of Technology , Victoria 3122, Australia
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29
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Senlik SS, Policht VR, Ogilvie JP. Two-Color Nonlinear Spectroscopy for the Rapid Acquisition of Coherent Dynamics. J Phys Chem Lett 2015; 6:2413-20. [PMID: 26266711 DOI: 10.1021/acs.jpclett.5b00861] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
There has been considerable recent interest in the observation of coherent dynamics in photosynthetic systems by 2D electronic spectroscopy (2DES). In particular, coherences that persist during the "waiting time" in a 2DES experiment have been attributed to electronic, vibrational, and vibronic origins in various systems. The typical method for characterizing these coherent dynamics requires the acquisition of 2DES spectra as a function of waiting time, essentially a 3DES measurement. Such experiments require lengthy data acquisition times that degrade the signal-to-noise of the recorded coherent dynamics. We present a rapid and high signal-to-noise pulse-shaping-based approach for the characterization of coherent dynamics. Using chlorophyll a, we demonstrate that this method retains much of the information content of a 3DES measurement and provides insight into the physical origin of the coherent dynamics, distinguishing between ground and excited state coherences. It also enables high resolution determination of ground and excited state frequencies.
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Affiliation(s)
- S Seckin Senlik
- †Department of Physics, University of Michigan, Ann Arbor, 48109, United States
| | - Veronica R Policht
- ‡Applied Physics Program, University of Michigan, Ann Arbor, 48109, United States
| | - Jennifer P Ogilvie
- †Department of Physics, University of Michigan, Ann Arbor, 48109, United States
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30
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Dong H, Fleming GR. Inhomogeneous Broadening Induced Long-Lived Integrated Two-Color Coherence Photon Echo Signal. J Phys Chem B 2014; 118:8956-61. [DOI: 10.1021/jp503045z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hui Dong
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Graham R. Fleming
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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31
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Vibronic coherence in oxygenic photosynthesis. Nat Chem 2014; 6:706-11. [DOI: 10.1038/nchem.2005] [Citation(s) in RCA: 303] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 06/16/2014] [Indexed: 01/05/2023]
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32
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Diers JR, Tang Q, Hondros CJ, Chen CY, Holten D, Lindsey JS, Bocian DF. Vibronic Characteristics and Spin-Density Distributions in Bacteriochlorins as Revealed by Spectroscopic Studies of 16 Isotopologues. Implications for Energy- and Electron-Transfer in Natural Photosynthesis and Artificial Solar-Energy Conversion. J Phys Chem B 2014; 118:7520-7532. [DOI: 10.1021/jp504286w] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- James R. Diers
- Department
of Chemistry, University of California, Riverside, California 92521-0403, United States
| | - Qun Tang
- Department
of Chemistry, University of California, Riverside, California 92521-0403, United States
| | - Christopher J. Hondros
- Department
of Chemistry, University of California, Riverside, California 92521-0403, United States
| | - Chih-Yuan Chen
- Department
of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - Dewey Holten
- Department
of Chemistry, Washington University, St. Louis, Missouri 63130-4889, United States
| | - Jonathan S. Lindsey
- Department
of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - David F. Bocian
- Department
of Chemistry, University of California, Riverside, California 92521-0403, United States
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