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Pawlak K, Paul S, Liu C, Reus M, Yang C, Holzwarth AR. On the PsbS-induced quenching in the plant major light-harvesting complex LHCII studied in proteoliposomes. PHOTOSYNTHESIS RESEARCH 2020; 144:195-208. [PMID: 32266611 DOI: 10.1007/s11120-020-00740-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 03/24/2020] [Indexed: 06/11/2023]
Abstract
Non-photochemical quenching (NPQ) in photosynthetic organisms provides the necessary photoprotection that allows them to cope with largely and quickly varying light intensities. It involves deactivation of excited states mainly at the level of the antenna complexes of photosystem II using still largely unknown molecular mechanisms. In higher plants the main contribution to NPQ is the so-called qE-quenching, which can be switched on and off in a few seconds. This quenching mechanism is affected by the low pH-induced activation of the small membrane protein PsbS which interacts with the major light-harvesting complex of photosystem II (LHCII). We are reporting here on a mechanistic study of the PsbS-induced LHCII quenching using ultrafast time-resolved chlorophyll (Chl) fluorescence. It is shown that the PsbS/LHCII interaction in reconstituted proteoliposomes induces highly effective and specific quenching of the LHCII excitation by a factor ≥ 20 via Chl-Chl charge-transfer (CT) state intermediates which are weakly fluorescent. Their characteristics are very broad fluorescence bands pronouncedly red-shifted from the typical unquenched LHCII fluorescence maximum. The observation of PsbS-induced Chl-Chl CT-state emission from LHCII in the reconstituted proteoliposomes is highly reminiscent of the in vivo quenching situation and also of LHCII quenching in vitro in aggregated LHCII, indicating a similar quenching mechanism in all those situations. The PsbS mutant lacking the two proton sensing Glu residues induced significant, but much smaller, quenching than wild type. Added zeaxanthin had only minor effects on the yield of quenching in the proteoliposomes. Overall our study shows that PsbS co-reconstituted with LHCII in liposomes represents an excellent in vitro model system with characteristics that are reflecting closely the in vivo qE-quenching situation.
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Affiliation(s)
- Krzysztof Pawlak
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, 45470, Mülheim, Germany
| | - Suman Paul
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, 45470, Mülheim, Germany
- Department of Biochemistry and Biophysics, Stockholm University, Svante Arrhenius väg 16C, 10691, Stockholm, Sweden
| | - Cheng Liu
- Key Laboratory of Plant Resources, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Michael Reus
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, 45470, Mülheim, Germany
| | - Chunhong Yang
- Key Laboratory of Plant Resources, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Alfred R Holzwarth
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, 45470, Mülheim, Germany.
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2
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Cox RP, Sandanayake S, Langford SJ, Bell TDM. Electron Transfer in a Naphthalene Diimide System Studied by Single-Molecule Delayed Fluorescence. Aust J Chem 2020. [DOI: 10.1071/ch19555] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Electron transfer (ET) is a key chemical reaction in nature and has been extensively studied in bulk systems, but remains challenging to investigate at the single-molecule level. A previously reported naphthalene diimide (NDI)-based system (Higginbotham et al., Chem. Commun. 2013, 49, 5061–5063) displays delayed fluorescence with good quantum yield (~0.5) and long-lived (nanoseconds) prompt and delayed fluorescence lifetimes, providing an opportunity to interrogate the underlying ET processes in single molecules. Time-resolved single-molecule fluorescence measurements enabled forward and reverse ET rate constants to be calculated for 45 individual molecules embedded in poly(methylmethacrylate) (PMMA) film. Interpretation of the results within the framework of Marcus–Hush theory for ET demonstrates that variation in both the electronic coupling and the driving force for ET is occurring from molecule to molecule within the PMMA film and over time for individual molecules.
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3
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Piatkowski L, Schanbacher C, Wackenhut F, Jamrozik A, Meixner AJ, Waluk J. Nature of Large Temporal Fluctuations of Hydrogen Transfer Rates in Single Molecules. J Phys Chem Lett 2018; 9:1211-1215. [PMID: 29470087 DOI: 10.1021/acs.jpclett.8b00299] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Double hydrogen transfer was monitored in single molecules of parent porphycene and its tetra- t-butyl derivative using confocal fluorescence microscopy. The molecules have been embedded in a polymer matrix. Under such conditions, a significant fraction of the population reveals a huge decrease of the tautomerization rate with respect to the value obtained from ensemble studies in solution. This effect is explained by a model that assumes that the rate is determined by the reorganization coordinate that involves slow relaxation of the polymer matrix. The model provides indirect evidence for the dominant role of tunneling. It is proposed that tautomerization in single molecules of the porphycene family can be used to probe polymer relaxation dynamics on the time scale ranging from picoseconds to minutes.
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Affiliation(s)
- Lukasz Piatkowski
- Institute of Physical Chemistry , Polish Academy of Sciences , Kasprzaka 44/52 , 01-224 Warsaw , Poland
| | - Christina Schanbacher
- Institute of Physical and Theoretical Chemistry , University of Tübingen , Auf der Morgenstelle 18 , D-72076 Tübingen , Germany
| | - Frank Wackenhut
- Institute of Physical and Theoretical Chemistry , University of Tübingen , Auf der Morgenstelle 18 , D-72076 Tübingen , Germany
| | - Agnieszka Jamrozik
- Institute of Physical Chemistry , Polish Academy of Sciences , Kasprzaka 44/52 , 01-224 Warsaw , Poland
| | - Alfred J Meixner
- Institute of Physical and Theoretical Chemistry , University of Tübingen , Auf der Morgenstelle 18 , D-72076 Tübingen , Germany
| | - Jacek Waluk
- Institute of Physical Chemistry , Polish Academy of Sciences , Kasprzaka 44/52 , 01-224 Warsaw , Poland
- Faculty of Mathematics and Science , Cardinal Stefan Wyszyński University , Dewajtis 5 , 01-815 Warsaw , Poland
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4
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Piwoński H, Sokołowski A, Waluk J. In Search for the Best Environment for Single Molecule Studies: Photostability of Single Terrylenediimide Molecules in Various Polymer Matrices. J Phys Chem Lett 2015; 6:2477-2482. [PMID: 26266722 DOI: 10.1021/acs.jpclett.5b01060] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Photobleaching is the main limiting factor in single molecule studies by optical techniques. We investigated the dependence of photostability of terrylene diimide (TDI) derivative on its environment using confocal fluorescence microscopy. Seven different polymers were tested. Depending on the matrix, photobleaching quantum yields vary by 2 orders of magnitude. Their values correlate with parameters characterizing oxygen mobility in polymers: diffusion coefficient and permeability. Poly(vinyl chloride) (PVC) and poly(methyl methacrylate) (PMMA) exhibit the lowest photodestruction quantum yields. Additional enhancement of photostability can be achieved by aging of PVC or by flushing the sample with nitrogen, which confirms the involvement of oxygen in photodestruction. Different character of the time traces of the intensity of emission from single TDI molecules is observed for different polymer matrices, ranging from intense blinking in the least stable polycarbonate, to practically no blinking in the most stable PVC. These results suggest a photodegradation mechanism involving self-sensitized photooxidation in oxygen complexes of TDI.
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Affiliation(s)
- Hubert Piwoński
- †Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44, 01-224 Warsaw, Poland
| | - Adam Sokołowski
- †Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44, 01-224 Warsaw, Poland
| | - Jacek Waluk
- †Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44, 01-224 Warsaw, Poland
- ‡Faculty of Mathematics and Science, Cardinal Stefan Wyszyński University, Dewajtis 5, 01-815 Warsaw, Poland
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5
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Hooley EN, Jones DJ, Greenham NC, Ghiggino KP, Bell TDM. Charge Transfer in Single Chains of a Donor–Acceptor Conjugated Tri-Block Copolymer. J Phys Chem B 2014; 119:7266-74. [DOI: 10.1021/jp510769p] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Emma N. Hooley
- School
of Chemistry, University of Melbourne, Parkville, Victoria 3010, Australia
| | - David J. Jones
- School
of Chemistry, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Neil C. Greenham
- Cavendish
Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 OHE, United Kingdom
| | - Kenneth P. Ghiggino
- School
of Chemistry, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Toby D. M. Bell
- School
of Chemistry, Monash University, Clayton, Victoria 3800, Australia
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6
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Yoo H, Bahng HW, Wasielewski MR, Kim D. Polymer matrix dependence of conformational dynamics within a π-stacked perylenediimide dimer and trimer revealed by single molecule fluorescence spectroscopy. Phys Chem Chem Phys 2012; 14:2001-7. [DOI: 10.1039/c2cp22377e] [Citation(s) in RCA: 20] [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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7
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Habuchi S, Fujita H, Michinobu T, Vacha M. Twist Angle Plays an Important Role in Photophysical Properties of a Donor–Acceptor-Type Conjugated Polymer: A Combined Ensemble and Single-Molecule Study. J Phys Chem B 2011; 115:14404-15. [DOI: 10.1021/jp209405k] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Satoshi Habuchi
- Department of Organic and Polymeric Materials, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8552, Japan
| | - Hiroyuki Fujita
- Department of Organic and Polymeric Materials, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8552, Japan
| | - Tsuyoshi Michinobu
- Global Edge Institute, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Martin Vacha
- Department of Organic and Polymeric Materials, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8552, Japan
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8
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Bag SS, Kundu R. Installation/Modulation of the Emission Response via Click Reaction. J Org Chem 2011; 76:3348-56. [DOI: 10.1021/jo200231k] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Subhendu Sekhar Bag
- Bioorganic Chemistry Laboratory, Department of Chemistry, Indian Institute of Technology, Guwahati-781039, India
| | - Rajen Kundu
- Bioorganic Chemistry Laboratory, Department of Chemistry, Indian Institute of Technology, Guwahati-781039, India
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9
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Fron E, Puhl L, Oesterling I, Li C, Müllen K, De Schryver FC, Hofkens J, Vosch T. Energy Transfer Pathways in a Rylene‐Based Triad. Chemphyschem 2010; 12:595-608. [DOI: 10.1002/cphc.201000665] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Indexed: 11/05/2022]
Affiliation(s)
- Eduard Fron
- Department of Chemistry and Institute for Nanoscale Physics and Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, 3001 Heverlee (Belgium)
| | - Larissa Puhl
- Max‐Planck‐Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz (Germany)
| | - Ingo Oesterling
- Max‐Planck‐Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz (Germany)
| | - Chen Li
- Max‐Planck‐Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz (Germany)
| | - Klaus Müllen
- Max‐Planck‐Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz (Germany)
| | - Frans C. De Schryver
- Department of Chemistry and Institute for Nanoscale Physics and Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, 3001 Heverlee (Belgium)
| | - Johan Hofkens
- Department of Chemistry and Institute for Nanoscale Physics and Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, 3001 Heverlee (Belgium)
| | - Tom Vosch
- Nano‐Science Center, Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen (Denmark), Fax: (+45) 353‐20‐322
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10
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Diehl FP, Roos C, Jankowiak HC, Berger R, Köhn A, Diezemann G, Basché T. Combined Experimental and Theoretical Study of the Vibronic Spectra of Perylenecarboximides. J Phys Chem B 2010; 114:1638-47. [DOI: 10.1021/jp909862x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Florian P. Diehl
- Johannes Gutenberg-University, Institute of Physical Chemistry, Jakob-Welder-Weg 11, D-55099 Mainz, Germany, and Frankfurt Institute for Advanced Studies, Johann Wolfgang Goethe-University, Ruth-Moufang-Str. 1, D-60438 Frankfurt am Main, Germany
| | - Claudia Roos
- Johannes Gutenberg-University, Institute of Physical Chemistry, Jakob-Welder-Weg 11, D-55099 Mainz, Germany, and Frankfurt Institute for Advanced Studies, Johann Wolfgang Goethe-University, Ruth-Moufang-Str. 1, D-60438 Frankfurt am Main, Germany
| | - Hans-Christian Jankowiak
- Johannes Gutenberg-University, Institute of Physical Chemistry, Jakob-Welder-Weg 11, D-55099 Mainz, Germany, and Frankfurt Institute for Advanced Studies, Johann Wolfgang Goethe-University, Ruth-Moufang-Str. 1, D-60438 Frankfurt am Main, Germany
| | - Robert Berger
- Johannes Gutenberg-University, Institute of Physical Chemistry, Jakob-Welder-Weg 11, D-55099 Mainz, Germany, and Frankfurt Institute for Advanced Studies, Johann Wolfgang Goethe-University, Ruth-Moufang-Str. 1, D-60438 Frankfurt am Main, Germany
| | - Andreas Köhn
- Johannes Gutenberg-University, Institute of Physical Chemistry, Jakob-Welder-Weg 11, D-55099 Mainz, Germany, and Frankfurt Institute for Advanced Studies, Johann Wolfgang Goethe-University, Ruth-Moufang-Str. 1, D-60438 Frankfurt am Main, Germany
| | - Gregor Diezemann
- Johannes Gutenberg-University, Institute of Physical Chemistry, Jakob-Welder-Weg 11, D-55099 Mainz, Germany, and Frankfurt Institute for Advanced Studies, Johann Wolfgang Goethe-University, Ruth-Moufang-Str. 1, D-60438 Frankfurt am Main, Germany
| | - Thomas Basché
- Johannes Gutenberg-University, Institute of Physical Chemistry, Jakob-Welder-Weg 11, D-55099 Mainz, Germany, and Frankfurt Institute for Advanced Studies, Johann Wolfgang Goethe-University, Ruth-Moufang-Str. 1, D-60438 Frankfurt am Main, Germany
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11
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Curutchet C, Feist FA, Averbeke BV, Mennucci B, Jacob J, Müllen K, Basché T, Beljonne D. Superexchange-mediated electronic energy transfer in a model dyad. Phys Chem Chem Phys 2010; 12:7378-85. [DOI: 10.1039/c003496g] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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12
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Zoon PD, Brouwer AM. A push-pull aromatic chromophore with a touch of merocyanine. Photochem Photobiol Sci 2009; 8:345-53. [DOI: 10.1039/b818371f] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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13
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Wöll D, Braeken E, Deres A, De Schryver FC, Uji-i H, Hofkens J. Polymers and single molecule fluorescence spectroscopy, what can we learn? Chem Soc Rev 2009; 38:313-28. [PMID: 19169450 DOI: 10.1039/b704319h] [Citation(s) in RCA: 179] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Dominik Wöll
- Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200 F, 3001 Heverlee, Belgium
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14
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Burguete MI, Galindo F, Izquierdo MA, Luis SV, Vigara L. Novel peptidomimetic macrocycles showing exciplex fluorescence. Tetrahedron 2007. [DOI: 10.1016/j.tet.2007.06.087] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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15
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Lang E, Hildner R, Engelke H, Osswald P, Würthner F, Köhler J. Comparison of the Photophysical Parameters for Three Perylene Bisimide Derivatives by Single-Molecule Spectroscopy. Chemphyschem 2007; 8:1487-96. [PMID: 17526040 DOI: 10.1002/cphc.200700186] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Characterization of the photophysical parameters for three perylene bisimide derivatives is presented. We exploited time-resolved and steady-state spectroscopy on both ensembles and single molecules under ambient as well as cryogenic (1.4 K) conditions. The finding is that these chromophores show extraordinary high fluorescence-emission rates, low intersystem crossing yields to the triplet state, and relatively short triplet lifetimes.
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Affiliation(s)
- Erwin Lang
- Experimental Physics IV and BIMF, University of Bayreuth, 95440 Bayreuth, Germany
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16
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Fron E, Schweitzer G, Jacob J, Van Vooren A, Beljonne D, Müllen K, Hofkens J, Van der Auweraer M, De Schryver FC. Singlet–Singlet Annihilation Leading to a Charge-Transfer Intermediate in Chromophore-End-Capped Pentaphenylenes. Chemphyschem 2007; 8:1386-93. [PMID: 17477340 DOI: 10.1002/cphc.200700136] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The excited-state properties of two peryleneimide chromophore end-capped pentaphenylene compounds were investigated in detail using femtosecond transient absorption and single-photon timing experiments. Singlet-singlet annihilation was found to promote one chromophore into a higher excited state and results in the formation of an ultra-short-living intermediate charge-transfer (CT) state in the S(n)-S(1) deactivation pathway. In low-polarity solvents, this CT state is found to be energetically higher than the first excited state and thus cannot be populated via one-photon excitation. The observed CT state decays with a time constant of about 1 ps to form the lowest singlet excited state. These results demonstrate the potential use of the singlet-singlet annihilation as a novel tool in studying reactions occurring in states that are energetically above the S(1).
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Affiliation(s)
- Eduard Fron
- Department of Chemistry, Katholieke Universiteit Leuven, Belgium
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17
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Neuteboom EE, Meskers SCJ, Beckers EHA, Chopin S, Janssen RAJ. Solvent Mediated Intramolecular Photoinduced Electron Transfer in a Fluorene-Perylene Bisimide Derivative. J Phys Chem A 2006; 110:12363-71. [PMID: 17091937 DOI: 10.1021/jp061905n] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Photoinduced electron transfer from fluorene to perylene bisimide has been studied for 2,7-bis(N-(1-hexylheptyl)-3,4:9,10-perylene-bisimide-N'-yl))-9,9-didodecylfluorene (PFP) in 11 different organic solvents. The intramolecular charge-separated state in PFP is almost isoenergetic with the locally excited state of the perylene bisimide. As a consequence of the small change in free energy for charge separation, the electron transfer rate strongly depends on subtle changes in the medium. The rate constant k(CS) for the electron transfer from fluorene to perylene bisimide moiety in the excited state varies over more than 2 orders of magnitude ( approximately 10(8)-10(10) s(-1)) with the solvent but does not show the familiar increase with polarity. The widely differing rate constants can be successfully explained by considering (1) the contribution of the polarization energy of the dipole moment in the transition state and by (2) the classical Marcus-Jortner model and assuming a spherical cavity for the charge-separated state. Using the first model, we show that lnk(CS) should vary linearly with Deltaf [Deltaf = (epsilon(r) - 1)/(2epsilon(r) + 1) - (n(2) - 1)/(2n(2) + 1), where epsilon(r) and n represent the static dielectric constant and the refractive index of the solvent, respectively], in accordance with experimental results. The second model, where the reorganization energy scales linearly with Deltaf, provides quantitative agreement with experimental rate constants within a factor of 2.
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Affiliation(s)
- Edda E Neuteboom
- Molecular Materials and Nanosystems, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
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18
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Schindler F, Lupton JM, Feldmann J. Spontaneous switching of permanent dipoles in single conjugated polymer molecules. Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2006.07.056] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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19
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Grey JK, Kim DY, Donley CL, Miller WL, Kim JS, Silva C, Friend RH, Barbara PF. Effect of Temperature and Chain Length on the Bimodal Emission Properties of Single Polyfluorene Copolymer Molecules. J Phys Chem B 2006; 110:18898-903. [PMID: 16986881 DOI: 10.1021/jp057361r] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Fluorescence emission spectra were recorded for isolated polymer chains of the polyfluorene copolymer, F8BT [poly(9,9-di-n-octylfluorene-alt-benzothiadiazole)], at 298 and 20 K for two molecular weights (chain lengths). For long-chain F8BT at 298 K, the observed distribution of single-molecule emission maxima G(Emax) is bimodal, with peaks at approximately 2.35 eV ("blue") and approximately 2.25 eV ("red"). Previously, the red forms have been assigned to polymer chains that possess intrachain contacts, which lowers the local singlet exciton energy. At approximately 20 K, G(Emax) collapses into a single broad distribution centered at approximately 2.3 eV for long-chain F8BT. However, this distribution can be further divided into a high-energy edge that is dominated by the "blue" form, while the remainder of the distribution is composed of the "red" form. Low-molecular-weight F8BT samples emit exclusively from the blue form, and no shift in peak maxima with low temperature was observed. A Franck-Condon analysis reveals a decrease in emitting state displacements between spectra measured at 298 and 20 K, suggesting that temperature-induced structural displacements are responsible for the change in the bimodal emission.
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Affiliation(s)
- John K Grey
- Center for Nano and Molecular Science and Technology and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712, USA
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Abstract
The development of nanotechnology using organic materials is one of the most intellectually and commercially exciting stories of our times. Advances in synthetic chemistry and in methods for the investigation and manipulation of individual molecules and small ensembles of molecules have produced major advances in the field of organic nanomaterials. The new insights into the optical and electronic properties of molecules obtained by means of single-molecule spectroscopy and scanning probe microscopy have spurred chemists to conceive and make novel molecular and supramolecular designs. Methods have also been sought to exploit the properties of these materials in optoelectronic devices, and prototypes and models for new nanoscale devices have been demonstrated. This Review aims to show how the interaction between synthetic chemistry and spectroscopy has driven the field of organic nanomaterials forward towards the ultimate goal of new technology.
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Affiliation(s)
- Andrew C Grimsdale
- Max-Planck-Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
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Bell TDM, Stefan A, Masuo S, Vosch T, Lor M, Cotlet M, Hofkens J, Bernhardt S, Müllen K, van der Auweraer M, Verhoeven JW, De Schryver FC. Electron Transfer at the Single-Molecule Level in a Triphenylamine-Perylene Imide Molecule. Chemphyschem 2005; 6:942-8. [PMID: 15884080 DOI: 10.1002/cphc.200400567] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Photoinduced electron transfer (ET) processes in a donor-acceptor system based on triphenylamine and perylene imide have been studied at the single-molecule (SM) and ensemble levels. The system exists as two isomers, one of which undergoes forward and reverse ET in toluene with decay constants of 3.0 and 2.2x10(9) s(-1), respectively, resulting in the dual emission of quenched and delayed fluorescence while the other isomer remains ET-inactive. The fluorescence of both isomers is heavily quenched in the more polar solvent, diethyl ether, by ET. A broad range of ET dynamics is seen at the SM level in polystryene with the two isomers nonresolvable indicating that the local nanoenvironment of the SMs varies considerably throughout the polymer matrix. Both the electronic coupling and the driving force for ET are shown to influence the ET dynamics. Many fluorescence trajectories of SMs show long periods (tens of milliseconds to seconds) where the count rate is attenuated either partly (a "dim" state) or to the background level (an "off-time"). During these periods, the reduction or interruption of emission is attributed to cycles of rapid charge separation followed by charge recombination to the ground state reducing the fluorescence quantum yield of the SM.
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Affiliation(s)
- Toby D M Bell
- Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, 3001 Heverlee, Belgium
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Bell TDM, Jacob J, Angeles-Izquierdo M, Fron E, Nolde F, Hofkens J, Müllen K, De Schryver FC. Charge transfer enhanced annihilation leading to deterministic single photon emission in rigid perylene end-capped polyphenylenes. Chem Commun (Camb) 2005:4973-5. [PMID: 16205818 DOI: 10.1039/b509651k] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two new peryleneimide end-capped polyphenylenes are shown to be deterministic single photon sources in PMMA films due to efficient annihilation between charge transfer states.
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Affiliation(s)
- Toby D M Bell
- Department of Chemistry, Celestijnenlaan 200F, Katholieke Universiteit Leuven, Heverlee, B-3001, Belgium
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