1
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Rode AJ, Arpin PC, Turner DB. Theoretical model of femtosecond coherence spectroscopy of vibronic excitons in molecular aggregates. J Chem Phys 2024; 160:164101. [PMID: 38647298 DOI: 10.1063/5.0200570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Accepted: 04/03/2024] [Indexed: 04/25/2024] Open
Abstract
When used as pump pulses in transient absorption spectroscopy measurements, femtosecond laser pulses can produce oscillatory signals known as quantum beats. The quantum beats arise from coherent superpositions of the states of the sample and are best studied in the Fourier domain using Femtosecond Coherence Spectroscopy (FCS), which consists of one-dimensional amplitude and phase plots of a specified oscillation frequency as a function of the detection frequency. Prior works have shown ubiquitous amplitude nodes and π phase shifts in FCS from excited-state vibrational wavepackets in monomer samples. However, the FCS arising from vibronic-exciton states in molecular aggregates have not been studied theoretically. Here, we use a model of vibronic-exciton states in molecular dimers based on displaced harmonic oscillators to simulate FCS for dimers in two important cases. Simulations reveal distinct spectral signatures of excited-state vibronic-exciton coherences in molecular dimers that may be used to distinguish them from monomer vibrational coherences. A salient result is that, for certain relative orientations of the transition dipoles, the key resonance condition between the electronic coupling and the frequency of the vibrational mode may yield strong enhancement of the quantum-beat amplitude and, perhaps, also cause a significant decrease of the oscillation frequency to a value far lower than the vibrational frequency. Future studies using these results will lead to new insights into the excited-state coherences generated in photosynthetic pigment-protein complexes.
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Affiliation(s)
- Alexander J Rode
- Micron School for Materials Science and Engineering, Boise State University, Boise, Idaho 83725, USA
| | - Paul C Arpin
- Department of Physics, California State University, Chico, Chico, California 95929, USA
| | - Daniel B Turner
- Micron School for Materials Science and Engineering, Boise State University, Boise, Idaho 83725, USA
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2
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Erić V, Li X, Dsouza L, Huijser A, Holzwarth AR, Buda F, Sevink GJA, de Groot HJM, Jansen TLC. Observation of Dark States in Two-Dimensional Electronic Spectra of Chlorosomes. J Phys Chem B 2024; 128:3575-3584. [PMID: 38569137 PMCID: PMC11033866 DOI: 10.1021/acs.jpcb.4c00067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 02/27/2024] [Accepted: 03/19/2024] [Indexed: 04/05/2024]
Abstract
Observations of low-lying dark states in several photosynthetic complexes challenge our understanding of the mechanisms behind their efficient energy transfer processes. Computational models are necessary for providing novel insights into the nature and function of dark states, especially since these are not directly accessible in spectroscopy experiments. Here, we will focus on signatures of dark-type states in chlorosomes, a light-harvesting complex from green sulfur bacteria well-known for uniting a broad absorption band with very efficient energy transfer. In agreement with experiments, our simulations of two-dimensional electronic spectra capture the ultrafast exciton transfer occurring in 100s of femtoseconds within a single chlorosome cylinder. The sub-100 fs process corresponds to relaxation within the single-excitation manifold in a single chlorosome tube, where all initially created populations in the bright exciton states are quickly transferred to dark-type exciton states. Structural inhomogeneities on the local scale cause a redistribution of the oscillator strength, leading to the emergence of these dark-type exciton states, which dominate ultrafast energy transfer. The presence of the dark-type exciton states suppresses energy loss from an isolated chlorosome via fluorescence quenching, as observed experimentally. Our results further question whether relaxation to dark-exciton states is a leading process or merely competes with transfer to the baseplate within the photosynthetic apparatus of green sulfur bacteria.
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Affiliation(s)
- Vesna Erić
- Zernike
Institute for Advanced Materials, University
of Groningen, 9747 AG Groningen, The Netherlands
| | - Xinmeng Li
- Department
of Chemistry and Hylleraas Centre for Quantum Molecular Sciences, University of Oslo, Sem Sælands vei 26, 0315 Oslo, Norway
| | - Lolita Dsouza
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2300 RA Leiden, The Netherlands
| | - Annemarie Huijser
- MESA+
Institute for Nanotechnology, University
of Twente, Drienerlolaan
5, 7522 NB Enschede, The Netherlands
| | - Alfred R. Holzwarth
- Department
of Biophysical Chemistry, Max Planck Institute
for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim, Germany
| | - Francesco Buda
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2300 RA Leiden, The Netherlands
| | - G. J. Agur Sevink
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2300 RA Leiden, The Netherlands
| | - Huub J. M. de Groot
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2300 RA Leiden, The Netherlands
| | - Thomas L. C. Jansen
- Zernike
Institute for Advanced Materials, University
of Groningen, 9747 AG Groningen, The Netherlands
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3
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Frehan SK, Dsouza L, Li X, Eríc V, Jansen TLC, Mul G, Holzwarth AR, Buda F, Sevink GJA, de Groot HJM, Huijser A. Photon Energy-Dependent Ultrafast Exciton Transfer in Chlorosomes of Chlorobium tepidum and the Role of Supramolecular Dynamics. J Phys Chem B 2023; 127:7581-7589. [PMID: 37611240 PMCID: PMC10493955 DOI: 10.1021/acs.jpcb.3c05282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 08/09/2023] [Indexed: 08/25/2023]
Abstract
The antenna complex of green sulfur bacteria, the chlorosome, is one of the most efficient supramolecular systems for efficient long-range exciton transfer in nature. Femtosecond transient absorption experiments provide new insight into how vibrationally induced quantum overlap between exciton states supports highly efficient long-range exciton transfer in the chlorosome of Chlorobium tepidum. Our work shows that excitation energy is delocalized over the chlorosome in <1 ps at room temperature. The following exciton transfer to the baseplate occurs in ∼3 to 5 ps, in line with earlier work also performed at room temperature, but significantly faster than at the cryogenic temperatures used in previous studies. This difference can be attributed to the increased vibrational motion at room temperature. We observe a so far unknown impact of the excitation photon energy on the efficiency of this process. This dependency can be assigned to distinct optical domains due to structural disorder, combined with an exciton trapping channel competing with exciton transfer toward the baseplate. An oscillatory transient signal damped in <1 ps has the highest intensity in the case of the most efficient exciton transfer to the baseplate. These results agree well with an earlier computational finding of exciton transfer driven by low-frequency rotational motion of molecules in the chlorosome. Such an exciton transfer process belongs to the quantum coherent regime, for which the Förster theory for intermolecular exciton transfer does not apply. Our work hence strongly indicates that structural flexibility is important for efficient long-range exciton transfer in chlorosomes.
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Affiliation(s)
- Sean K. Frehan
- MESA+
Institute for Nanotechnology, University
of Twente, 7500 AE Enschede, The Netherlands
| | - Lolita Dsouza
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2300 RA Leiden, The Netherlands
| | - Xinmeng Li
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2300 RA Leiden, The Netherlands
- Department
of Chemistry and Hylleraas Centre for Quantum Molecular Sciences, University of Oslo, 0315 Oslo, Norway
| | - Vesna Eríc
- Zernike
Institute of Advanced Materials, University
of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Thomas L. C. Jansen
- Zernike
Institute of Advanced Materials, University
of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Guido Mul
- MESA+
Institute for Nanotechnology, University
of Twente, 7500 AE Enschede, The Netherlands
| | - Alfred R. Holzwarth
- Max
Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Francesco Buda
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2300 RA Leiden, The Netherlands
| | - G. J. Agur Sevink
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2300 RA Leiden, The Netherlands
| | - Huub J. M. de Groot
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2300 RA Leiden, The Netherlands
| | - Annemarie Huijser
- MESA+
Institute for Nanotechnology, University
of Twente, 7500 AE Enschede, The Netherlands
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4
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Erić V, Castro JL, Li X, Dsouza L, Frehan SK, Huijser A, Holzwarth AR, Buda F, Sevink GJA, de Groot HJM, Jansen TLC. Ultrafast Anisotropy Decay Reveals Structure and Energy Transfer in Supramolecular Aggregates. J Phys Chem B 2023; 127:7487-7496. [PMID: 37594912 PMCID: PMC10476209 DOI: 10.1021/acs.jpcb.3c04719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 07/20/2023] [Indexed: 08/20/2023]
Abstract
Chlorosomes from green bacteria perform the most efficient light capture and energy transfer, as observed among natural light-harvesting antennae. Hence, their unique functional properties inspire developments in artificial light-harvesting and molecular optoelectronics. We examine two distinct organizations of the molecular building blocks as proposed in the literature, demonstrating how these organizations alter light capture and energy transfer, which can serve as a mechanism that the bacteria utilize to adapt to changes in light conditions. Spectral simulations of polarization-resolved two-dimensional electronic spectra unravel how changes in the helicity of chlorosomal aggregates alter energy transfer. We show that ultrafast anisotropy decay presents a spectral signature that reveals contrasting energy pathways in different chlorosomes.
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Affiliation(s)
- Vesna Erić
- Zernike
Institute for Advanced Materials, University
of Groningen, 9747 AG Groningen, The Netherlands
| | - Jorge Luis Castro
- Zernike
Institute for Advanced Materials, University
of Groningen, 9747 AG Groningen, The Netherlands
| | - Xinmeng Li
- Department
of Chemistry and Hylleraas Centre for Quantum Molecular Sciences, University of Oslo, Sem Sælands vei 26, 0315 Oslo, Norway
| | - Lolita Dsouza
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2300 RA Leiden, The Netherlands
| | - Sean K. Frehan
- MESA+
Institute for Nanotechnology, University
of Twente, Drienerlolaan 5, 7522 NB Enschede, The Netherlands
| | - Annemarie Huijser
- MESA+
Institute for Nanotechnology, University
of Twente, Drienerlolaan 5, 7522 NB Enschede, The Netherlands
| | - Alfred R. Holzwarth
- Department
of Biophysical Chemistry, Max Planck Institute
for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim, Germany
| | - Francesco Buda
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2300 RA Leiden, The Netherlands
| | - G. J. Agur Sevink
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2300 RA Leiden, The Netherlands
| | - Huub J. M. de Groot
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2300 RA Leiden, The Netherlands
| | - Thomas L. C. Jansen
- Zernike
Institute for Advanced Materials, University
of Groningen, 9747 AG Groningen, The Netherlands
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5
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Erić V, Li X, Dsouza L, Frehan SK, Huijser A, Holzwarth AR, Buda F, Sevink GJA, de Groot HJM, Jansen TLC. Manifestation of Hydrogen Bonding and Exciton Delocalization on the Absorption and Two-Dimensional Electronic Spectra of Chlorosomes. J Phys Chem B 2023; 127:1097-1109. [PMID: 36696537 PMCID: PMC9923760 DOI: 10.1021/acs.jpcb.2c07143] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Chlorosomes are supramolecular aggregates that contain thousands of bacteriochlorophyll molecules. They perform the most efficient ultrafast excitation energy transfer of all natural light-harvesting complexes. Their broad absorption band optimizes light capture. In this study, we identify the microscopic sources of the disorder causing the spectral width and reveal how it affects the excited state properties and the optical response of the system. We combine molecular dynamics, quantum chemical calculations, and response function calculations to achieve this goal. The predicted linear and two-dimensional electronic spectra are found to compare well with experimental data reproducing all key spectral features. Our analysis of the microscopic model reveals the interplay of static and dynamic disorder from the molecular perspective. We find that hydrogen bonding motifs are essential for a correct description of the spectral line shape. Furthermore, we find that exciton delocalization over tens to hundreds of molecules is consistent with the two-dimensional electronic spectra.
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Affiliation(s)
- Vesna Erić
- University
of Groningen, Zernike Institute
for Advanced Materials, 9747
AG Groningen, The Netherlands
| | - Xinmeng Li
- Department
of Chemistry and Hylleraas Centre for Quantum Molecular Sciences, University of Oslo, Sem Sælands vei 26, 0315 Oslo, Norway
| | - Lolita Dsouza
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2300 RA Leiden, The Netherlands
| | - Sean K. Frehan
- MESA+
Institute for Nanotechnology, University
of Twente, Drienerlolaan 5, 7522 NB Enschede, The Netherlands
| | - Annemarie Huijser
- MESA+
Institute for Nanotechnology, University
of Twente, Drienerlolaan 5, 7522 NB Enschede, The Netherlands
| | - Alfred R. Holzwarth
- Department
of Biophysical Chemistry, Max Planck Institute
for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim, Germany
| | - Francesco Buda
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2300 RA Leiden, The Netherlands
| | - G. J. Agur Sevink
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2300 RA Leiden, The Netherlands
| | - Huub J. M. de Groot
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2300 RA Leiden, The Netherlands
| | - Thomas L. C. Jansen
- University
of Groningen, Zernike Institute
for Advanced Materials, 9747
AG Groningen, The Netherlands,
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6
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Kim J, Jeon J, Yoon TH, Cho M. Two-dimensional electronic spectroscopy of bacteriochlorophyll a with synchronized dual mode-locked lasers. Nat Commun 2020; 11:6029. [PMID: 33247112 PMCID: PMC7699642 DOI: 10.1038/s41467-020-19912-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 10/28/2020] [Indexed: 11/09/2022] Open
Abstract
How atoms and electrons in a molecule move during a chemical reaction and how rapidly energy is transferred to or from the surroundings can be studied with flashes of laser light. However, despite prolonged efforts to develop various coherent spectroscopic techniques, the lack of an all-encompassing method capable of both femtosecond time resolution and nanosecond relaxation measurement has hampered various applications of studying correlated electron dynamics and vibrational coherences in functional materials and biological systems. Here, we demonstrate that two broadband (>300 nm) synchronized mode-locked lasers enable two-dimensional electronic spectroscopy (2DES) study of chromophores such as bacteriochlorophyll a in condensed phases to measure both high-resolution coherent vibrational spectrum and nanosecond electronic relaxation. We thus anticipate that the dual mode-locked laser-based 2DES developed and demonstrated here would be of use for unveiling the correlation between the quantum coherence and exciton dynamics in light-harvesting protein complexes and semiconducting materials.
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Affiliation(s)
- JunWoo Kim
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Seoul, 02841, Republic of Korea.,Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA
| | - Jonggu Jeon
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Seoul, 02841, Republic of Korea
| | - Tai Hyun Yoon
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Seoul, 02841, Republic of Korea. .,Department of Physics, Korea University, Seoul, 02841, Republic of Korea.
| | - Minhaeng Cho
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Seoul, 02841, Republic of Korea. .,Deparment of Chemistry, Korea University, Seoul, 02841, Republic of Korea.
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7
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Sardjan AS, Westerman FP, Ogilvie JP, Jansen TLC. Observation of Ultrafast Coherence Transfer and Degenerate States with Polarization-Controlled Two-Dimensional Electronic Spectroscopy. J Phys Chem B 2020; 124:9420-9427. [PMID: 32990439 PMCID: PMC7586392 DOI: 10.1021/acs.jpcb.0c08126] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
![]()
Optical
spectroscopy is a powerful tool to interrogate quantum
states of matter. We present simulation results for the cross-polarized
two-dimensional electronic spectra of the light-harvesting system
LH2 of purple bacteria. We identify a spectral feature on the diagonal,
which we assign to ultrafast coherence transfer between degenerate
states. The implication for the interpretation of previous experiments
on different systems and the potential use of this feature are discussed.
In particular, we foresee that this kind of feature will be useful
for identifying mixed degenerate states and for identifying the origin
of symmetry breaking disorder in systems like LH2. Furthermore, this
may help identify both vibrational and electronic states in biological
systems such as proteins and solid-state materials such as hybrid
perovskites.
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Affiliation(s)
- Andy S Sardjan
- Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Floris P Westerman
- Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Jennifer P Ogilvie
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Thomas L C Jansen
- Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, The Netherlands
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8
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Li X, Buda F, de Groot HJM, Sevink GJA. Dynamic Disorder Drives Exciton Transfer in Tubular Chlorosomal Assemblies. J Phys Chem B 2020; 124:4026-4035. [PMID: 32343578 PMCID: PMC7246976 DOI: 10.1021/acs.jpcb.0c00441] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Chlorosomes stand out for their highly efficient excitation energy transfer (EET) in extreme low light conditions. Yet, little is known about the EET when a chlorosome is excited to a pure state that is an eigenstate of the exciton Hamiltonian. In this work, we consider the dynamic disorder in the intermolecular electronic coupling explicitly by calculating the electronic coupling terms in the Hamiltonian using nuclear coordinates that are taken from molecular dynamics simulation trajectories. We show that this dynamic disorder is capable of driving the evolution of the exciton, being a stationary state of the initial Hamiltonian. In particular, long-distance excitation energy transfer between domains of high exciton population and oscillatory behavior of the population in the site basis are observed, in line with two-dimensional electronic spectroscopy studies. We also found that in the high exciton population domains, their population variation is correlated with their overall coupling strength. Analysis in a reference state basis shows that such dynamic disorder, originating from thermal energy, creates a fluctuating landscape for the exciton and promotes the EET process. We propose such dynamic disorder as an important microscopic origin for the high efficient EET widely observed in different types of chlorosomes, bioinspired tubular aggregates, or other light-harvesting complexes.
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Affiliation(s)
- Xinmeng Li
- Leiden University, Leiden Institute of Chemistry, Einsteinweg 55, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Francesco Buda
- Leiden University, Leiden Institute of Chemistry, Einsteinweg 55, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Huub J M de Groot
- Leiden University, Leiden Institute of Chemistry, Einsteinweg 55, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - G J Agur Sevink
- Leiden University, Leiden Institute of Chemistry, Einsteinweg 55, P.O. Box 9502, 2300 RA Leiden, The Netherlands
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9
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Cao J, Cogdell RJ, Coker DF, Duan HG, Hauer J, Kleinekathöfer U, Jansen TLC, Mančal T, Miller RJD, Ogilvie JP, Prokhorenko VI, Renger T, Tan HS, Tempelaar R, Thorwart M, Thyrhaug E, Westenhoff S, Zigmantas D. Quantum biology revisited. SCIENCE ADVANCES 2020; 6:eaaz4888. [PMID: 32284982 PMCID: PMC7124948 DOI: 10.1126/sciadv.aaz4888] [Citation(s) in RCA: 184] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 01/06/2020] [Indexed: 05/21/2023]
Abstract
Photosynthesis is a highly optimized process from which valuable lessons can be learned about the operating principles in nature. Its primary steps involve energy transport operating near theoretical quantum limits in efficiency. Recently, extensive research was motivated by the hypothesis that nature used quantum coherences to direct energy transfer. This body of work, a cornerstone for the field of quantum biology, rests on the interpretation of small-amplitude oscillations in two-dimensional electronic spectra of photosynthetic complexes. This Review discusses recent work reexamining these claims and demonstrates that interexciton coherences are too short lived to have any functional significance in photosynthetic energy transfer. Instead, the observed long-lived coherences originate from impulsively excited vibrations, generally observed in femtosecond spectroscopy. These efforts, collectively, lead to a more detailed understanding of the quantum aspects of dissipation. Nature, rather than trying to avoid dissipation, exploits it via engineering of exciton-bath interaction to create efficient energy flow.
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Affiliation(s)
- Jianshu Cao
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Richard J. Cogdell
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Science, University of Glasgow, Glasgow G12 8QQ, UK
| | - David F. Coker
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, MA 02215, USA
| | - Hong-Guang Duan
- Atomically Resolved Dynamics Department, Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany
- I. Institut für Theoretische Physik, Universität Hamburg, Jungiusstrasse 9, 20355 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, 22761 Hamburg, Germany
| | - Jürgen Hauer
- Technische Universität München, Dynamische Spektroskopien, Fakultät für Chemie, Lichtenbergstr. 4, 85748 Garching, Germany, and Photonics Institute, TU Wien, 1040 Vienna, Austria
| | - Ulrich Kleinekathöfer
- Department of Physics and Earth Science, Jacobs University Bremen, Campus Ring 1, 28759 Bremen, Germany
| | - Thomas L. C. Jansen
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, Netherlands
| | - Tomáš Mančal
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, CZ-12116 Prague 2, Czech Republic
| | - R. J. Dwayne Miller
- Atomically Resolved Dynamics Department, Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, 22761 Hamburg, Germany
- Departments of Chemistry and Physics, University of Toronto, Toronto, ON M5S 3H6, Canada
| | | | - Valentyn I. Prokhorenko
- Atomically Resolved Dynamics Department, Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany
| | - Thomas Renger
- Institute of Theoretical Physics, Department of Theoretical Biophysics, Johannes Kepler University Linz, Altenberger Str. 69, 4040 Linz, Austria
| | - Howe-Siang Tan
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Roel Tempelaar
- Department of Chemistry, Columbia University, 3000 Broadway, New York, NY 10027, USA
| | - Michael Thorwart
- I. Institut für Theoretische Physik, Universität Hamburg, Jungiusstrasse 9, 20355 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, 22761 Hamburg, Germany
| | - Erling Thyrhaug
- Technische Universität München, Dynamische Spektroskopien, Fakultät für Chemie, Lichtenbergstr. 4, 85748 Garching, Germany, and Photonics Institute, TU Wien, 1040 Vienna, Austria
| | - Sebastian Westenhoff
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg 40530, Sweden
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10
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11
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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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12
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Treatment of Herzberg-Teller and non-Condon effects in optical spectra with Hierarchical Equations of Motion. Chem Phys 2018. [DOI: 10.1016/j.chemphys.2018.08.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Rathbone HW, Davis JA, Michie KA, Goodchild SC, Robertson NO, Curmi PMG. Coherent phenomena in photosynthetic light harvesting: part two-observations in biological systems. Biophys Rev 2018; 10:1443-1463. [PMID: 30242555 PMCID: PMC6233342 DOI: 10.1007/s12551-018-0456-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 09/06/2018] [Indexed: 10/28/2022] Open
Abstract
Considerable debate surrounds the question of whether or not quantum mechanics plays a significant, non-trivial role in photosynthetic light harvesting. Many have proposed that quantum superpositions and/or quantum transport phenomena may be responsible for the efficiency and robustness of energy transport present in biological systems. The critical experimental observations comprise the observation of coherent oscillations or "quantum beats" via femtosecond laser spectroscopy, which have been observed in many different light harvesting systems. Part Two of this review aims to provide an overview of experimental observations of energy transfer in the most studied light harvesting systems. Length scales, derived from crystallographic studies, are combined with energy and time scales of the beats observed via spectroscopy. A consensus is emerging that most long-lived (hundreds of femtoseconds) coherent phenomena are of vibrational or vibronic origin, where the latter may result in coherent excitation transport within a protein complex. In contrast, energy transport between proteins is likely to be incoherent in nature. The question of whether evolution has selected for these non-trivial quantum phenomena may be an unanswerable question, as dense packings of chromophores will lead to strong coupling and hence non-trivial quantum phenomena. As such, one cannot discern whether evolution has optimised light harvesting systems for high chromophore density or for the ensuing quantum effects as these are inextricably linked and cannot be switched off.
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Affiliation(s)
- Harry W Rathbone
- School of Physics, The University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - Jeffery A Davis
- Centre for Quantum and Optical Science, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, Victoria, 3122, Australia
| | - Katharine A Michie
- School of Physics, The University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - Sophia C Goodchild
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Neil O Robertson
- 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.
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14
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Li X, Buda F, de Groot HJ, Sevink GJA. Contrasting Modes of Self-Assembly and Hydrogen-Bonding Heterogeneity in Chlorosomes of Chlorobaculum tepidum. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2018; 122:14877-14888. [PMID: 30258522 PMCID: PMC6150686 DOI: 10.1021/acs.jpcc.8b01790] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 05/30/2018] [Indexed: 06/08/2023]
Abstract
Chlorosome antennae form an interesting class of materials for studying the role of structural motifs and dynamics in nonadiabatic energy transfer. They perform robust and highly quantum-efficient transfer of excitonic energy while allowing for compositional variation and completely lacking the usual regulatory proteins. Here, we first cast the geometrical analysis for ideal tubular scaffolding models into a formal framework, to relate effective helical properties of the assembly structures to established characterization data for various types of chlorosomes. This analysis shows that helicity is uniquely defined for chlorosomes composed of bacteriochlorophyll (BChl) d and that three chiral angles are consistent with the nuclear magnetic resonance (NMR) and electron microscope data for BChl c, including two novel ones that are at variance with current interpretations of optical data based on perfect cylindrical symmetry. We use this information as a starting point for investigating dynamic and static heterogeneity at the molecular level by unconstrained molecular dynamics. We first identify a rotational degree of freedom, along the Mg-OH coordination bond, that alternates along the syn-anti stacks and underlies the (flexible) curvature on a larger scale. Because rotation directly relates to the formation or breaking of interstack hydrogen bonds of the O-H···O=C structural motif along the syn-anti stacks, we analyzed the relative fractions of hydrogen-bonded and the nonbonded regions, forming stripe domains in otherwise spectroscopically homogeneous curved slabs. The ratios 7:3 for BChl c and 9:1 for BChl d for the two distinct structural components agree well with the signal intensities determined by NMR. In addition, rotation with curvature-independent formation of stripe domains offers a viable explanation for the localization and dispersion of exciton states over two fractions, as observed in single chlorosome fluorescence decay studies.
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15
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Dostál J, Fennel F, Koch F, Herbst S, Würthner F, Brixner T. Direct observation of exciton-exciton interactions. Nat Commun 2018; 9:2466. [PMID: 29941915 PMCID: PMC6018121 DOI: 10.1038/s41467-018-04884-4] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 06/01/2018] [Indexed: 12/11/2022] Open
Abstract
Natural light harvesting as well as optoelectronic and photovoltaic devices depend on efficient transport of energy following photoexcitation. Using common spectroscopic methods, however, it is challenging to discriminate one-exciton dynamics from multi-exciton interactions that arise when more than one excitation is present in the system. Here we introduce a coherent two-dimensional spectroscopic method that provides a signal only in case that the presence of one exciton influences the behavior of another one. Exemplarily, we monitor exciton diffusion by annihilation in a perylene bisimide-based J-aggregate. We determine quantitatively the exciton diffusion constant from exciton–exciton-interaction 2D spectra and reconstruct the annihilation-free dynamics for large pump powers. The latter enables for ultrafast spectroscopy at much higher intensities than conventionally possible and thus improves signal-to-noise ratios for multichromophore systems; the former recovers spatio–temporal dynamics for a broad range of phenomena in which exciton interactions are present. Some photo-physical processes in multichromophore systems might get triggered only if two excitations are present. Here, the authors introduce exciton–exciton-interaction 2D spectroscopy, which is a non-linear optical method that can selectively track the time evolution of such effects.
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Affiliation(s)
- Jakub Dostál
- Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Franziska Fennel
- Institut für Organische Chemie, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.,Center for Nanosystems Chemistry (CNC), Universität Würzburg, Theodor-Boveri-Weg, 97074, Würzburg, Germany
| | - Federico Koch
- Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Stefanie Herbst
- Institut für Organische Chemie, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Frank Würthner
- Institut für Organische Chemie, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany. .,Center for Nanosystems Chemistry (CNC), Universität Würzburg, Theodor-Boveri-Weg, 97074, Würzburg, Germany.
| | - Tobias Brixner
- Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany. .,Center for Nanosystems Chemistry (CNC), Universität Würzburg, Theodor-Boveri-Weg, 97074, Würzburg, Germany.
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16
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Identification and characterization of diverse coherences in the Fenna-Matthews-Olson complex. Nat Chem 2018; 10:780-786. [PMID: 29785033 DOI: 10.1038/s41557-018-0060-5] [Citation(s) in RCA: 137] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 04/04/2018] [Indexed: 11/08/2022]
Abstract
The idea that excitonic (electronic) coherences are of fundamental importance to natural photosynthesis gained popularity when slowly dephasing quantum beats (QBs) were observed in the two-dimensional electronic spectra of the Fenna-Matthews-Olson (FMO) complex at 77 K. These were assigned to superpositions of excitonic states, a controversial interpretation, as the strong chromophore-environment interactions in the complex suggest fast dephasing. Although it has been pointed out that vibrational motion produces similar spectral signatures, a concrete assignment of these oscillatory signals to distinct physical processes is still lacking. Here we revisit the coherence dynamics of the FMO complex using polarization-controlled two-dimensional electronic spectroscopy, supported by theoretical modelling. We show that the long-lived QBs are exclusively vibrational in origin, whereas the dephasing of the electronic coherences is completed within 240 fs even at 77 K. We further find that specific vibrational coherences are produced via vibronically coupled excited states. The presence of such states suggests that vibronic coupling is relevant for photosynthetic energy transfer.
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17
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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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18
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Du J, Yuan W, Xing X, Miyatake T, Tamiaki H, Kobayashi T, Leng Y. Spectral modulation observed in artificial photosynthetic complexes by real-time vibrational spectroscopy. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.05.050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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19
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Ma F, Yu LJ, Hendrikx R, Wang-Otomo ZY, van Grondelle R. Excitonic and Vibrational Coherence in the Excitation Relaxation Process of Two LH1 Complexes as Revealed by Two-Dimensional Electronic Spectroscopy. J Phys Chem Lett 2017; 8:2751-2756. [PMID: 28585830 DOI: 10.1021/acs.jpclett.7b00824] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Ultrafast excitation relaxation within a manifold exciton state and long-lived vibrational coherence are two universal characteristics of photosynthetic antenna complexes. In this work, we studied the two-dimensional electronic spectra of two core light-harvesting (LH1) complexes of Thermochromatium (Tch.) tepidum, native Ca2+-LH1 and modified Ba2+-LH1. The role of the vibrational coherence in the exciton relaxation was revealed by comparing the two LH1 with similar structures but different electronic properties and by the evolution of the exciton and vibrational coherence as a function of temperature.
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Affiliation(s)
- Fei Ma
- Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam , De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Long-Jiang Yu
- Faculty of Science, Ibaraki University , Mito, Ibaraki 310-8512, Japan
- Research Institute for Interdisciplinary Science, Okayama University , 3-1-1 Tsushima Naka, Okayama 700-8530, Japan
| | - Ruud Hendrikx
- Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam , De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | | | - Rienk van Grondelle
- Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam , De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
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20
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21
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Han D, Xue B, Du J, Kobayashi T, Miyatake T, Tamiaki H, Xing X, Yuan W, Li Y, Leng Y. Excitonic and vibrational coherence in artificial photosynthetic systems studied by negative-time ultrafast laser spectroscopy. Phys Chem Chem Phys 2016; 18:24252-60. [PMID: 27531576 DOI: 10.1039/c6cp03540j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Quantum coherences between excitonic states are believed to have a substantial impact on excitation energy transfer in photosynthetic systems. Here, the excitonic and vibrational coherence relaxation dynamics of artificially synthetic chlorosomes are studied by a sub 7 fs negative-time-delay laser spectroscopy at room temperature. The results provide direct evidence for the quantum coherence of the excitonic dephasing time of 23 ± 1 fs at physiologically relevant temperatures, which is significant in the initial step of energy transfer in chlorosome or chlorosome-like photosynthetic systems. Meanwhile, coherent molecular vibrations in the excited state are also detected without the effect of wave-packet motion in the ground state, which shows that the excited state wave-packet motion contributes greatly to the vibrational modes of ∼150 and ∼1340 cm(-1) in artificial chlorosome systems.
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Affiliation(s)
- Dongjia Han
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.
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22
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Somoza Márquez A, Chen L, Sun K, Zhao Y. Probing ultrafast excitation energy transfer of the chlorosome with exciton–phonon variational dynamics. Phys Chem Chem Phys 2016; 18:20298-311. [DOI: 10.1039/c5cp06491k] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Excitation energy transfer of the chlorosome is investigated using exciton–phonon variational dynamics revealing ultrafast energy relaxation and exciton delocalization on a 100 fs scale.
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Affiliation(s)
| | - Lipeng Chen
- Division of Materials Science
- Nanyang Technological University
- Singapore 639798
- Singapore
| | - Kewei Sun
- School of Science
- Hangzhou Dianzi University
- Hangzhou 310018
- China
| | - Yang Zhao
- Division of Materials Science
- Nanyang Technological University
- Singapore 639798
- Singapore
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23
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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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24
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Han D, Du J, Kobayashi T, Miyatake T, Tamiaki H, Li Y, Leng Y. Excitonic Relaxation and Coherent Vibrational Dynamics in Zinc Chlorin Aggregates for Artificial Photosynthetic Systems. J Phys Chem B 2015; 119:12265-73. [PMID: 26307640 DOI: 10.1021/acs.jpcb.5b06214] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dongjia Han
- State
Key Laboratory of High Field Laser Physics, Shanghai Institute of
Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Juan Du
- State
Key Laboratory of High Field Laser Physics, Shanghai Institute of
Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Takayoshi Kobayashi
- Advanced
Ultrafast Laser Research Center, University of Electro-Communications, 1-5-1, Chofugaoka, Chofu, Tokyo 182-8585, Japan
- JST, CREST, K’s Gobancho, 7 Gobancho,
Chiyoda-ku, Tokyo, 102-0076 Japan
| | - Tomohiro Miyatake
- Department
of Materials Chemistry, Ryukoku University, Otsu, Shiga 520-2194, Japan
| | - Hitoshi Tamiaki
- Department
of Bioscience and Biotechnology, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
| | - Yanyan Li
- State
Key Laboratory of High Field Laser Physics, Shanghai Institute of
Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Yuxin Leng
- State
Key Laboratory of High Field Laser Physics, Shanghai Institute of
Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
- FSA
Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240, China
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25
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Vibronic origin of long-lived coherence in an artificial molecular light harvester. Nat Commun 2015; 6:7755. [PMID: 26158602 PMCID: PMC4510969 DOI: 10.1038/ncomms8755] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 06/04/2015] [Indexed: 01/11/2023] Open
Abstract
Natural and artificial light-harvesting processes have recently gained new interest. Signatures of long-lasting coherence in spectroscopic signals of biological systems have been repeatedly observed, albeit their origin is a matter of ongoing debate, as it is unclear how the loss of coherence due to interaction with the noisy environments in such systems is averted. Here we report experimental and theoretical verification of coherent exciton–vibrational (vibronic) coupling as the origin of long-lasting coherence in an artificial light harvester, a molecular J-aggregate. In this macroscopically aligned tubular system, polarization-controlled 2D spectroscopy delivers an uncongested and specific optical response as an ideal foundation for an in-depth theoretical description. We derive analytical expressions that show under which general conditions vibronic coupling leads to prolonged excited-state coherence. Two-dimensional spectroscopy revealed oscillatory signals in photosynthesis' exciton dynamics, but crowded spectra impede the identification of what sustains the oscillations. Here the authors probe an J-aggregate, whose uncongested response shows that vibronic coupling is responsible for the sustained coherence.
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26
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Camargo FVA, Anderson HL, Meech SR, Heisler IA. Full Characterization of Vibrational Coherence in a Porphyrin Chromophore by Two-Dimensional Electronic Spectroscopy. J Phys Chem A 2014; 119:95-101. [DOI: 10.1021/jp511881a] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Franco V. A. Camargo
- School
of Chemistry, Norwich Research Park, University of East Anglia, Norwich NR4 7TJ, U.K
- CAPES Foundation,
Ministry of Education of Brazil, Brasilia - DF 70040-202, Brazil
| | - Harry L. Anderson
- Department
of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford OX1 3TA, U.K
| | - Stephen R. Meech
- School
of Chemistry, Norwich Research Park, University of East Anglia, Norwich NR4 7TJ, U.K
| | - Ismael A. Heisler
- School
of Chemistry, Norwich Research Park, University of East Anglia, Norwich NR4 7TJ, U.K
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27
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Dostál J, Vácha F, Pšenčík J, Zigmantas D. 2D Electronic Spectroscopy Reveals Excitonic Structure in the Baseplate of a Chlorosome. J Phys Chem Lett 2014; 5:1743-1747. [PMID: 26270377 DOI: 10.1021/jz5005279] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In green photosynthetic bacteria, the chlorosome baseplate mediates excitation energy transfer from the interior of the light-harvesting chlorosome toward the reaction centers. However, the electronic states of the baseplate remain unexplored, hindering the mechanistic understanding of the baseplate as an excitation energy collector and mediator. Here we use two-dimensional spectroscopy to study the excited state structure and internal energy relaxation in the baseplate of green sulfur bacterium Chlorobaculum tepidum. We resolved an exciton system with four energy states, indicating that the organization of the pigments in the baseplate is more complex than was thought before and constitutes at least four bacteriochlorophyll molecules in a close contact. Based on the finding that the energy of the baseplate states is in the same range as in the adjacent Fenna-Matthews-Olson complex, we propose a "lateral" energy transfer pathway, where excitation energy can flow through the photosynthetic unit via all the states of individual complexes.
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Affiliation(s)
- Jakub Dostál
- †Department of Chemical Physics, Lund University, P.O. Box 124, 221 00 Lund, Sweden
- ‡Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 3, 121 16 Prague, Czech Republic
| | - František Vácha
- §Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic
| | - Jakub Pšenčík
- ‡Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 3, 121 16 Prague, Czech Republic
| | - Donatas Zigmantas
- †Department of Chemical Physics, Lund University, P.O. Box 124, 221 00 Lund, Sweden
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