1
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Chaudhry S, Wu Y, Cao Z, Li S, Canada JL, Gu X, Risko C, Mei J. Evolution of Chain Dynamics and Oxidation States with Increasing Chain Length for a Donor–Acceptor-Conjugated Oligomer Series. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c00963] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Saadia Chaudhry
- Department of Chemistry, Purdue University West Lafayette, Indiana 47907, United States
| | - Yukun Wu
- Department of Chemistry, Purdue University West Lafayette, Indiana 47907, United States
| | - Zhiqiang Cao
- School of Polymer Science and Engineering, The University of Southern Mississippi, Hattiesburg, Mississippi 39406, United States
| | - Shi Li
- Department of Chemistry & Center for Applied Energy Research (CAER), University of Kentucky, Lexington, Kentucky 40506, United States
| | - Jodie L. Canada
- Department of Chemistry & Center for Applied Energy Research (CAER), University of Kentucky, Lexington, Kentucky 40506, United States
| | - Xiaodan Gu
- School of Polymer Science and Engineering, The University of Southern Mississippi, Hattiesburg, Mississippi 39406, United States
| | - Chad Risko
- Department of Chemistry & Center for Applied Energy Research (CAER), University of Kentucky, Lexington, Kentucky 40506, United States
| | - Jianguo Mei
- Department of Chemistry, Purdue University West Lafayette, Indiana 47907, United States
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2
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Kim W, Tahara S, Kuramochi H, Takeuchi S, Kim T, Tahara T, Kim D. Mode‐Specific Vibrational Analysis of Exciton Delocalization and Structural Dynamics in Conjugated Oligomers. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202102168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Woojae Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional, π-Electronic Systems Yonsei University Seoul 03722 Korea
- Current address: Department of Chemistry and Chemical Biology Cornell University Ithaca NY 14853 USA
| | - Shinya Tahara
- Molecular Spectroscopy Laboratory RIKEN 2-1 Hirosawa Wako 351-0198 Japan
- Current address: Graduate School of Pharmaceutical Sciences Tohoku University 6-3 Aramaki-aza-Aoba, Aoba-ku Sendai 980-8578 Japan
| | - Hikaru Kuramochi
- Molecular Spectroscopy Laboratory RIKEN 2-1 Hirosawa Wako 351-0198 Japan
- Ultrafast Spectroscopy Research Team RIKEN Center for Advanced Photonics (RAP) 2-1 Hirosawa Wako 351-0198 Japan
- JST PRESTO 4-1-8 Honcho Kawaguchi 332-0012 Japan
- Current address: Research Center of Integrative Molecular Systems (CIMoS) Institute for Molecular Science 38 Nishigo-Naka, Myodaji Okazaki 444-8585 Japan
| | - Satoshi Takeuchi
- Molecular Spectroscopy Laboratory RIKEN 2-1 Hirosawa Wako 351-0198 Japan
- Ultrafast Spectroscopy Research Team RIKEN Center for Advanced Photonics (RAP) 2-1 Hirosawa Wako 351-0198 Japan
- Current address: Graduate School of Material Science University of Hyogo 3-2-1 Koto Kamigori Ako 678-1297 Japan
| | - Taeyeon Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional, π-Electronic Systems Yonsei University Seoul 03722 Korea
- Current address: Department of Chemistry and Institute for Sustainability and Energy at Northwestern Northwestern University Evanston IL 60208-3113 USA
| | - Tahei Tahara
- Molecular Spectroscopy Laboratory RIKEN 2-1 Hirosawa Wako 351-0198 Japan
- Ultrafast Spectroscopy Research Team RIKEN Center for Advanced Photonics (RAP) 2-1 Hirosawa Wako 351-0198 Japan
| | - Dongho Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional, π-Electronic Systems Yonsei University Seoul 03722 Korea
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3
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Kim W, Tahara S, Kuramochi H, Takeuchi S, Kim T, Tahara T, Kim D. Mode-Specific Vibrational Analysis of Exciton Delocalization and Structural Dynamics in Conjugated Oligomers. Angew Chem Int Ed Engl 2021; 60:16999-17008. [PMID: 33730430 DOI: 10.1002/anie.202102168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Indexed: 11/09/2022]
Abstract
Exciton delocalization in organic semiconducting polymers, affected by structures at a molecular level, plays a crucial role in modulating relaxation pathways, such as charge generation and singlet fission, which can boost device efficiency. However, the structural diversity of polymers and broad signals from typical electronic spectroscopy have their limits when it comes to revealing the interplay between local structures and exciton delocalization. To tackle these problems, we apply femtosecond stimulated Raman spectroscopy in archetypical conjugated oligothiophenes with different chain lengths. We observed Raman frequency dispersions of symmetric bond stretching modes and mode-specific kinetics in the S1 Raman spectra, which underpins the subtle and complex interplay between exciton delocalization and bond length alternation along the conjugation coordinate. Our results provide a more general picture of exciton delocalization in the context of molecular structures for conjugated materials.
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Affiliation(s)
- Woojae Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional, π-Electronic Systems, Yonsei University, Seoul, 03722, Korea.,Current address: Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Shinya Tahara
- Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako, 351-0198, Japan.,Current address: Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aramaki-aza-Aoba, Aoba-ku, Sendai, 980-8578, Japan
| | - Hikaru Kuramochi
- Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako, 351-0198, Japan.,Ultrafast Spectroscopy Research Team, RIKEN Center for Advanced Photonics (RAP), 2-1 Hirosawa, Wako, 351-0198, Japan.,JST PRESTO, 4-1-8 Honcho, Kawaguchi, 332-0012, Japan.,Current address: Research Center of Integrative Molecular Systems (CIMoS), Institute for Molecular Science, 38 Nishigo-Naka, Myodaji, Okazaki, 444-8585, Japan
| | - Satoshi Takeuchi
- Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako, 351-0198, Japan.,Ultrafast Spectroscopy Research Team, RIKEN Center for Advanced Photonics (RAP), 2-1 Hirosawa, Wako, 351-0198, Japan.,Current address: Graduate School of Material Science, University of Hyogo, 3-2-1 Koto, Kamigori, Ako, 678-1297, Japan
| | - Taeyeon Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional, π-Electronic Systems, Yonsei University, Seoul, 03722, Korea.,Current address: Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, IL, 60208-3113, USA
| | - Tahei Tahara
- Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako, 351-0198, Japan.,Ultrafast Spectroscopy Research Team, RIKEN Center for Advanced Photonics (RAP), 2-1 Hirosawa, Wako, 351-0198, Japan
| | - Dongho Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional, π-Electronic Systems, Yonsei University, Seoul, 03722, Korea
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4
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Peterhans L, Nicolaidou E, Diamantis P, Alloa E, Leclerc M, Surin M, Clément S, Rothlisberger U, Banerji N, Hayes SC. Structural and Photophysical Templating of Conjugated Polyelectrolytes with Single-Stranded DNA. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2020; 32:7347-7362. [PMID: 33122875 PMCID: PMC7587141 DOI: 10.1021/acs.chemmater.0c02251] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 08/06/2020] [Indexed: 06/11/2023]
Abstract
A promising approach to influence and control the photophysical properties of conjugated polymers is directing their molecular conformation by templating. We explore here the templating effect of single-stranded DNA oligomers (ssDNAs) on cationic polythiophenes with the goal to uncover the intermolecular interactions that direct the polymer backbone conformation. We have comprehensively characterized the optical behavior and structure of the polythiophenes in conformationally distinct complexes depending on the sequence of nucleic bases and addressed the effect on the ultrafast excited-state relaxation. This, in combination with molecular dynamics simulations, allowed us a detailed atomistic-level understanding of the structure-property correlations. We find that electrostatic and other noncovalent interactions direct the assembly with the polymer, and we identify that optimal templating is achieved with (ideally 10-20) consecutive cytosine bases through numerous π-stacking interactions with the thiophene rings and side groups of the polymer, leading to a rigid assembly with ssDNA, with highly ordered chains and unique optical signatures. Our insights are an important step forward in an effective approach to structural templating and optoelectronic control of conjugated polymers and organic materials in general.
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Affiliation(s)
- Lisa Peterhans
- Department
of Chemistry and Biochemistry, University
of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Eliana Nicolaidou
- Department
of Chemistry, University of Cyprus, P.O. Box 20537, 1678, Nicosia, Cyprus
| | - Polydefkis Diamantis
- Laboratory
of Computational Chemistry and Biochemistry, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Elisa Alloa
- Department
of Chemistry, University of Cyprus, P.O. Box 20537, 1678, Nicosia, Cyprus
| | - Mario Leclerc
- Department
of Chemistry, Université Laval, G1K 7P4 Quebec
City, Quebec, Canada
| | - Mathieu Surin
- Laboratory
for Chemistry of Novel Materials, Center for Innovation in Materials
and Polymers, University of Mons −
UMONS, 20 Place du Parc, B-7000 Mons, Belgium
| | - Sébastien Clément
- Institut
Charles Gerhardt Montpellier, ICGM, UMR 5253 CNRS, Université de Montpellier, Place Eugène Bataillon, F-34095 Montpellier, Cedex
05, France
| | - Ursula Rothlisberger
- Laboratory
of Computational Chemistry and Biochemistry, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Natalie Banerji
- Department
of Chemistry and Biochemistry, University
of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Sophia C. Hayes
- Department
of Chemistry, University of Cyprus, P.O. Box 20537, 1678, Nicosia, Cyprus
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5
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Hestand NJ, Spano FC. Expanded Theory of H- and J-Molecular Aggregates: The Effects of Vibronic Coupling and Intermolecular Charge Transfer. Chem Rev 2018; 118:7069-7163. [PMID: 29664617 DOI: 10.1021/acs.chemrev.7b00581] [Citation(s) in RCA: 719] [Impact Index Per Article: 119.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The electronic excited states of molecular aggregates and their photophysical signatures have long fascinated spectroscopists and theoreticians alike since the advent of Frenkel exciton theory almost 90 years ago. The influence of molecular packing on basic optical probes like absorption and photoluminescence was originally worked out by Kasha for aggregates dominated by Coulombic intermolecular interactions, eventually leading to the classification of J- and H-aggregates. This review outlines advances made in understanding the relationship between aggregate structure and photophysics when vibronic coupling and intermolecular charge transfer are incorporated. An assortment of packing geometries is considered from the humble molecular dimer to more exotic structures including linear and bent aggregates, two-dimensional herringbone and "HJ" aggregates, and chiral aggregates. The interplay between long-range Coulomb coupling and short-range charge-transfer-mediated coupling strongly depends on the aggregate architecture leading to a wide array of photophysical behaviors.
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Affiliation(s)
- Nicholas J Hestand
- Department of Chemistry , Temple University , Philadelphia , Pennsylvania 19122 , United States
| | - Frank C Spano
- Department of Chemistry , Temple University , Philadelphia , Pennsylvania 19122 , United States
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6
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Shimizu H, Park KH, Otani H, Aoyagi S, Nishinaga T, Aso Y, Kim D, Iyoda M. A Saturn-Like Complex Composed of Macrocyclic Oligothiophene and C 60 Fullerene: Structure, Stability, and Photophysical Properties in Solution and the Solid State. Chemistry 2018; 24:3793-3801. [PMID: 29315942 DOI: 10.1002/chem.201705565] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Indexed: 11/11/2022]
Abstract
A Saturn-like 1:1 complex composed of macrocyclic oligothiophene E-8T7A and C60 fullerene (C60 ) was synthesized to investigate the interaction between macrocyclic oligothiophenes and C60 in solution and the solid state. Because the Saturn-like 1:1 complex E-8T7A⋅C60 is mainly stabilized by van der Waals interactions between C60 and the sulfur atoms of the E-8T7A macrocycle, C60 is rather weakly incorporated inside the macro-ring in solution. However, in the solid state the Saturn-like 1:1 complex preferentially formed single crystals or nanostructured polymorphs. Interestingly, X-ray analysis and theoretical calculations exhibited hindered rotation of C60 in the Saturn-like complex due to interactions between C60 and the sulfur atoms. Furthermore, the photoinduced charge transfer (CT) interaction between E-8T7A and C60 in solution was investigated by using femtosecond transient absorption (TA) spectroscopy. The ultrafast TA spectral changes in the photoinduced absorption bands were attributed to the CT process in the Saturn-like structure.
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Affiliation(s)
- Hideyuki Shimizu
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Hachioji, Tokyo, 192-0397, Japan
| | - Kyu Hyung Park
- Department of Chemistry and Spectroscopy Laboratory for, Functional π-Electronic Systems, Yonsei University, Seoul, 03722, Korea
| | - Hiroyuki Otani
- Graduate School of Environment and Information Sciences, Yokohama National University, Hodogaya-ku, Yokohama, Kanagawa, 240-8501, Japan
| | - Shinobu Aoyagi
- Department of Information and Basic Science, Nagoya City University, Nagoya, 467-8501, Japan
| | - Tohru Nishinaga
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Hachioji, Tokyo, 192-0397, Japan
| | - Yoshio Aso
- The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka, 767-0047, Japan
| | - Dongho Kim
- Department of Chemistry and Spectroscopy Laboratory for, Functional π-Electronic Systems, Yonsei University, Seoul, 03722, Korea
| | - Masahiko Iyoda
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Hachioji, Tokyo, 192-0397, Japan
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7
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Hu Z, Shao B, Geberth GT, Vanden Bout DA. Effects of molecular architecture on morphology and photophysics in conjugated polymers: from single molecules to bulk. Chem Sci 2018; 9:1101-1111. [PMID: 29675155 PMCID: PMC5887865 DOI: 10.1039/c7sc03465b] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 12/30/2017] [Indexed: 01/16/2023] Open
Abstract
A definitive comprehension of morphology and photophysics in conjugated polymers at multiple length scales demands both single molecule spectroscopy and well-controlled molecular architectures.
Conjugated polymers (CPs) possess a wide range of desirable properties, including accessible energetic bandgaps, synthetic versatility, and mechanical flexibility, which make them attractive for flexible and wearable optoelectronic devices. An accurate and comprehensive understanding about the morphology–photophysics relations in CPs lays the groundwork for their development in these applications. However, due to the complex roles of chemical structure, side-chains, backbone, and intramolecular interactions, CPs can exhibit heterogeneity in both their morphology and optoelectronic properties even at the single chain level. This molecular level heterogeneity together with complicated intermolecular interactions found in bulk CP materials severely obscures the deterministic information about the morphology and photophysics at different hierarchy levels. To counter this complexity and offer a clearer picture for the properties of CP materials, we highlight the approach of probing material systems with specific structural features via single molecule/aggregate spectroscopy (SMS). This review article covers recent advances achieved through such an approach regarding the important morphological and photophysical properties of CPs. After a brief review of the typical characteristics of CPs, we present detailed discussions of structurally well-defined model systems of CPs, from manipulated backbones and side-chains, up to nano-aggregates, studied with SMS to offer deterministic relations between morphology and photophysics from single chains building up to bulk states.
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Affiliation(s)
- Zhongjian Hu
- Department of Chemistry , University of Texas at Austin , USA .
| | - Beiyue Shao
- Department of Chemistry , University of Texas at Austin , USA .
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8
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Park KH, Kim W, Yang J, Kim D. Excited-state structural relaxation and exciton delocalization dynamics in linear and cyclic π-conjugated oligothiophenes. Chem Soc Rev 2018; 47:4279-4294. [DOI: 10.1039/c7cs00605e] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
π-Conjugated oligothiophene is considered a chain segment of its polymeric counterpart with simper excited-state dynamics and spectral signatures.
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Affiliation(s)
- Kyu Hyung Park
- Department of Chemistry and Spectroscopy Laboratory for Functional π-Electronic Systems
- Yonsei University
- Seoul 03722
- Korea
| | - Woojae Kim
- Department of Chemistry and Spectroscopy Laboratory for Functional π-Electronic Systems
- Yonsei University
- Seoul 03722
- Korea
| | - Jaesung Yang
- Department of Chemistry and Medical Chemistry
- Yonsei University
- Wonju
- Korea
| | - Dongho Kim
- Department of Chemistry and Spectroscopy Laboratory for Functional π-Electronic Systems
- Yonsei University
- Seoul 03722
- Korea
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9
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Simine L, Rossky PJ. Relating Chromophoric and Structural Disorder in Conjugated Polymers. J Phys Chem Lett 2017; 8:1752-1756. [PMID: 28350467 DOI: 10.1021/acs.jpclett.7b00290] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The optoelectronic properties of amorphous conjugated polymers are sensitive to the details of the conformational disorder, and spectroscopy provides the means for structural characterization of the fragments of the chain that interact with light-"chromophores". A faithful interpretation of spectroscopic conformational signatures, however, presents a theoretical challenge. Here we investigate the relationship between the ground-state optical gaps, the properties of the excited states, and the structural features of chromophores of a single molecule poly(3-hexyl)-thiophene (P3HT) using quantum-classical atomistic simulations. Our results demonstrate that chromophoric disorder arises through the interplay between excited-state delocalization and electron-hole polarization, controlled by the torsional disorder introduced by side chains. Within this conceptual framework, we predict and explain the counterintuitive spectral behavior of P3HT, a red-shifted absorption, despite shortening of chromophores, with increasing temperature. This discussion introduces the concept of disorder-induced separation of charges in amorphous conjugated polymers.
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Affiliation(s)
- Lena Simine
- Department of Chemistry, Rice University , Houston, Texas 77005, United States
| | - Peter J Rossky
- Department of Chemistry, Rice University , Houston, Texas 77005, United States
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10
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Alfonso Hernandez L, Nelson T, Gelin MF, Lupton JM, Tretiak S, Fernandez-Alberti S. Interference of Interchromophoric Energy-Transfer Pathways in π-Conjugated Macrocycles. J Phys Chem Lett 2016; 7:4936-4944. [PMID: 27934058 DOI: 10.1021/acs.jpclett.6b02236] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The interchromophoric energy-transfer pathways between weakly coupled units in a π-conjugated phenylene-ethynylene macrocycle and its half-ring analogue have been investigated using the nonadiabatic excited-state molecular dynamics approach. To track the flow of electronic transition density between macrocycle units, we formulate a transition density flux analysis adapted from the statistical minimum flow method previously developed to investigate vibrational energy flow. Following photoexcitation, transition density is primarily delocalized on two chromophore units and the system undergoes ultrafast energy transfer, creating a localized excited state on a single unit. In the macrocycle, distinct chromophore units donate transition density to a single acceptor unit but do not interchange transition density among each other. We find that energy transfer in the macrocycle is slower than in the corresponding half ring because of the presence of multiple interfering energy-transfer pathways. Simulation results are validated by modeling the fluorescence anisotropy decay.
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Affiliation(s)
| | - Tammie Nelson
- Theoretical Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Maxim F Gelin
- Department of Chemistry, Technische Universität München , D-85747 Garching, Germany
| | - John M Lupton
- Institut für Angewandte und Experimentelle Physik, Universität Regensburg , Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Sergei Tretiak
- Theoretical Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
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11
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Park KH, Cho JW, Kim TW, Shimizu H, Nakao K, Iyoda M, Kim D. Defining Cyclic-Acyclic Exciton Transition at the Single-Molecule Level: Size-Dependent Conformational Heterogeneity and Exciton Delocalization in Ethynylene-Bridged Cyclic Oligothiophenes. J Phys Chem Lett 2016; 7:1260-1266. [PMID: 26983838 DOI: 10.1021/acs.jpclett.6b00360] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Conformational disorder in π-conjugated cyclic systems plays a crucial role in controlling the extent of exciton delocalization in much the same way as that in linear counterparts. However, to date, there have been no detailed spectroscopic investigations on the nature of excitons in π-conjugated cyclic systems at the single-molecule level. Herein, we studied the effect of conformational disorder on the excitonic behaviors of cyclic oligothiophenes composed of 6, 8, 10, and 12 subunits (C-6T, C-8T, C-10T, and C-12T, respectively) by employing single-molecule fluorescence spectroscopy. We found that, due to the cyclic symmetry constraint which suppresses S1-S0 transition, small and rigid C-6T and C-8T exhibit extremely long fluorescence lifetimes, while short lifetimes typical of linear systems are dominant in large, flexible C-10T and C-12T. Two-dimensional correlation maps between fluorescence lifetimes and spectral positions show that, by torsional defects created through continued photoexcitation, fully delocalized cyclic excitons shrink to form acyclic excitons in the case of C-10T, while localized acyclic excitons from initial states are maintained in the case of C-12T. The distribution of linear dichroism values from C-6T to C-10T gradually broadens but narrows in C-12T, suggesting a cyclic-to-acyclic transition in excitonic nature between C-10T and C-12T.
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Affiliation(s)
- Kyu Hyung Park
- Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University , Seoul 03722, Korea
| | - Jae-Won Cho
- Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University , Seoul 03722, Korea
| | - Tae-Woo Kim
- Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University , Seoul 03722, Korea
| | - Hideyuki Shimizu
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University , Hachioji, Tokyo 192-0397, Japan
| | - Kazumi Nakao
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University , Hachioji, Tokyo 192-0397, Japan
| | - Masahiko Iyoda
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University , Hachioji, Tokyo 192-0397, Japan
| | - Dongho Kim
- Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University , Seoul 03722, Korea
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