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Fujiwara E, Orita R, Vyšniauskas A, Franckevičius M, Ishige R, Gulbinas V, Ando S. Ultrafast Spectroscopic Analysis of Pressure-Induced Variations of Excited-State Energy and Intramolecular Proton Transfer in Semi-Aliphatic Polyimide Films. J Phys Chem B 2021; 125:2425-2434. [PMID: 33629863 DOI: 10.1021/acs.jpcb.0c11500] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The relationship between the photoexcitation dynamics and the structures of semi-aliphatic polyimides (3H-PIs) was investigated using ultrafast fluorescent emission spectroscopy at atmospheric and increased pressures of up to 4 GPa. The 3H-PI films exhibited prominent fluorescence with extremely large Stokes shifts (Δν > 10 000 cm-1) through an excited-state intramolecular proton transfer (ESIPT) induced by keto-enol tautomerism at the isolated dianhydride moiety. The incorporation of bulky -CH3 and -CF3 side groups at the diamine moiety of the PIs increased the quantum yields of the ESIPT fluorescence owing to an enhanced interchain free volume. In addition, 3H-PI films emitted another fluorescence at shorter wavelengths originating from closely packed polyimide (PI) chains (in aggregated forms), which was mediated through a Förster resonance energy transfer (FRET) from an isolated enol form into aggregated forms. The FRET process became more dominant than the ESIPT process at higher pressures owing to an enhancement of the FRET efficiency caused by the increased dipole-dipole interactions associated with a densification of the PI chain packing. The efficiency of the FRET rapidly increased by applying pressure up to 1 GPa owing to an effective compression of the interchain free volume and additionally gradually increased at higher pressures owing to structural and/or conformational changes in the main chains.
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Affiliation(s)
- Eisuke Fujiwara
- Department of Chemical Science and Engineering, Tokyo Institute of Technology, Ookayama 2-12-1-E4-5, Meguro-ku, Tokyo 152-8552, Japan
| | - Ryoji Orita
- Department of Chemical Science and Engineering, Tokyo Institute of Technology, Ookayama 2-12-1-E4-5, Meguro-ku, Tokyo 152-8552, Japan
| | - Aurimas Vyšniauskas
- Center for Physical Sciences and Technology, Sauletekio av. 3, Vilnius 10257, Lithuania
| | - Marius Franckevičius
- Center for Physical Sciences and Technology, Sauletekio av. 3, Vilnius 10257, Lithuania
| | - Ryohei Ishige
- Department of Chemical Science and Engineering, Tokyo Institute of Technology, Ookayama 2-12-1-E4-5, Meguro-ku, Tokyo 152-8552, Japan
| | - Vidmantas Gulbinas
- Center for Physical Sciences and Technology, Sauletekio av. 3, Vilnius 10257, Lithuania
| | - Shinji Ando
- Department of Chemical Science and Engineering, Tokyo Institute of Technology, Ookayama 2-12-1-E4-5, Meguro-ku, Tokyo 152-8552, Japan
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Perevedentsev A, Francisco-López A, Shi X, Braendle A, Caseri WR, Goñi AR, Campoy-Quiles M. Homoconjugation in Light-Emitting Poly(phenylene methylene)s: Origin and Pressure-Enhanced Photoluminescence. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c01153] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Aleksandr Perevedentsev
- Institute of Materials Science of Barcelona (ICMAB-CSIC), Campus of the UAB, 08193 Bellaterra, Spain
| | - Adrián Francisco-López
- Institute of Materials Science of Barcelona (ICMAB-CSIC), Campus of the UAB, 08193 Bellaterra, Spain
| | - Xingyuan Shi
- Department of Physics and Centre for Plastic Electronics, Imperial College London, SW7 2AZ London, U.K
| | - Andreas Braendle
- Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
| | - Walter R. Caseri
- Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
| | - Alejandro R. Goñi
- Institute of Materials Science of Barcelona (ICMAB-CSIC), Campus of the UAB, 08193 Bellaterra, Spain
- ICREA, Passeig Lluís Companys 23, 08010 Barcelona, Spain
| | - Mariano Campoy-Quiles
- Institute of Materials Science of Barcelona (ICMAB-CSIC), Campus of the UAB, 08193 Bellaterra, Spain
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Muto K, Fujiwara E, Ishige R, Ando S. Analysis of Pressure-induced Variations in the Crystalline Structures of Polyimides Having Flexible Linkages by Wide-Angle X-ray Diffraction. J PHOTOPOLYM SCI TEC 2020. [DOI: 10.2494/photopolymer.33.583] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Koichiro Muto
- Department of Chemical Science and Engineering, Tokyo Institute of Technology
| | - Eisuke Fujiwara
- Department of Chemical Science and Engineering, Tokyo Institute of Technology
| | - Ryohei Ishige
- Department of Chemical Science and Engineering, Tokyo Institute of Technology
| | - Shinji Ando
- Department of Chemical Science and Engineering, Tokyo Institute of Technology
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Fujiwara E, Fukudome H, Takizawa K, Ishige R, Ando S. Pressure-Induced Variations of Aggregation Structures in Colorless and Transparent Polyimide Films Analyzed by Optical Microscopy, UV–Vis Absorption, and Fluorescence Spectroscopy. J Phys Chem B 2018; 122:8985-8997. [DOI: 10.1021/acs.jpcb.8b06423] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Eisuke Fujiwara
- Department of Chemical Science and Engineering, Tokyo Institute of Technology, Ookayama 2-12-1-E4-5, Meguro-ku, Tokyo 152-8552, Japan
| | - Hiroshi Fukudome
- Department of Chemical Science and Engineering, Tokyo Institute of Technology, Ookayama 2-12-1-E4-5, Meguro-ku, Tokyo 152-8552, Japan
| | - Kazuhiro Takizawa
- Department of Chemical Science and Engineering, Tokyo Institute of Technology, Ookayama 2-12-1-E4-5, Meguro-ku, Tokyo 152-8552, Japan
| | - Ryohei Ishige
- Department of Chemical Science and Engineering, Tokyo Institute of Technology, Ookayama 2-12-1-E4-5, Meguro-ku, Tokyo 152-8552, Japan
| | - Shinji Ando
- Department of Chemical Science and Engineering, Tokyo Institute of Technology, Ookayama 2-12-1-E4-5, Meguro-ku, Tokyo 152-8552, Japan
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Knaapila M, Guha S. Blue emitting organic semiconductors under high pressure: status and outlook. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2016; 79:066601. [PMID: 27116082 DOI: 10.1088/0034-4885/79/6/066601] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
This review describes essential optical and emerging structural experiments that use high GPa range hydrostatic pressure to probe physical phenomena in blue-emitting organic semiconductors including π-conjugated polyfluorene and related compounds. The work emphasizes molecular structure and intermolecular self-organization that typically determine transport and optical emission in π-conjugated oligomers and polymers. In this context, hydrostatic pressure through diamond anvil cells has proven to be an elegant tool to control structure and interactions without chemical intervention. This has been highlighted by high pressure optical spectroscopy whilst analogous x-ray diffraction experiments remain less frequent. By focusing on a class of blue-emitting π-conjugated polymers, polyfluorenes, this article reviews optical spectroscopic studies under hydrostatic pressure, addressing the impact of molecular and intermolecular interactions on optical excitations, electron-phonon interaction, and changes in backbone conformations. This picture is connected to the optical high pressure studies of other π-conjugated systems and emerging x-ray scattering experiments from polyfluorenes which provides a structure-property map of pressure-driven intra- and interchain interactions. Key obstacles to obtain further advances are identified and experimental methods to resolve them are suggested.
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Affiliation(s)
- Matti Knaapila
- Department of Physics, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
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Shi J, Liu Y, Guo R, Li X, He A, Gao Y, Wei Y, Liu C, Zhao Y, Xu Y, Noda I, Wu J. Design of a New Concentration Series for the Orthogonal Sample Design Approach and Estimation of the Number of Reactions in Chemical Systems. APPLIED SPECTROSCOPY 2015; 69:1229-1242. [PMID: 26647046 DOI: 10.1366/14-07759] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A new concentration series is proposed for the construction of a two-dimensional (2D) synchronous spectrum for orthogonal sample design analysis to probe intermolecular interaction between solutes dissolved in the same solutions. The obtained 2D synchronous spectrum possesses the following two properties: (1) cross peaks in the 2D synchronous spectra can be used to reflect intermolecular interaction reliably, since interference portions that have nothing to do with intermolecular interaction are completely removed, and (2) the two-dimensional synchronous spectrum produced can effectively avoid accidental collinearity. Hence, the correct number of nonzero eigenvalues can be obtained so that the number of chemical reactions can be estimated. In a real chemical system, noise present in one-dimensional spectra may also produce nonzero eigenvalues. To get the correct number of chemical reactions, we classified nonzero eigenvalues into significant nonzero eigenvalues and insignificant nonzero eigenvalues. Significant nonzero eigenvalues can be identified by inspecting the pattern of the corresponding eigenvector with help of the Durbin-Watson statistic. As a result, the correct number of chemical reactions can be obtained from significant nonzero eigenvalues. This approach provides a solid basis to obtain insight into subtle spectral variations caused by intermolecular interaction.
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Affiliation(s)
- Jiajia Shi
- College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang 050024, China
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Takizawa K, Fukudome H, Kozaki Y, Ando S. Pressure-Induced Changes in Crystalline Structures of Polyimides Analyzed by Wide-Angle X-ray Diffraction at High Pressures. Macromolecules 2014. [DOI: 10.1021/ma500236z] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kazuhiro Takizawa
- Department of Chemistry & Materials Science, Tokyo Institute of Technology, Ookayama 2-12-1-E4-5, Meguro-ku, Tokyo 152-8552, Japan
| | - Hiroshi Fukudome
- Department of Chemistry & Materials Science, Tokyo Institute of Technology, Ookayama 2-12-1-E4-5, Meguro-ku, Tokyo 152-8552, Japan
| | - Yukiko Kozaki
- Department of Chemistry & Materials Science, Tokyo Institute of Technology, Ookayama 2-12-1-E4-5, Meguro-ku, Tokyo 152-8552, Japan
| | - Shinji Ando
- Department of Chemistry & Materials Science, Tokyo Institute of Technology, Ookayama 2-12-1-E4-5, Meguro-ku, Tokyo 152-8552, Japan
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Knaapila M, Konôpková Z, Torkkeli M, Haase D, Liermann HP, Guha S, Scherf U. Structural study of helical polyfluorene under high quasihydrostatic pressure. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 87:022602. [PMID: 23496539 DOI: 10.1103/physreve.87.022602] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 12/27/2012] [Indexed: 05/24/2023]
Abstract
We report on an x-ray diffraction (XRD) study of helical poly[9,9-bis(2-ethylhexyl)fluorene] (PF2/6) under high quasihydrostatic pressure and show an effect of pressure on the torsion angle (dihedral angle) between adjunct repeat units and on the hexagonal unit cell. A model for helical backbone conformation is constructed. The theoretical position for the most prominent 00l x-ray reflection is calculated as a function of torsion angle. The XRD of high molecular weight PF2/6 (M(n)=30 kg/mol) is measured through a diamond anvil cell upon pressure increase from 1 to 10 GPa. The theoretically considered 00l reflection is experimentally identified, and its shift with the increasing pressure is found to be consistent with the decreasing torsion angle between 2 and 6 GPa. This indicates partial backbone planarization towards a more open helical structure. The h00 peak is identified, and its shift together with the broadening of 00l implies impairment of the ambient hexagonal order, which begins at or below 2 GPa. Previously collected high-pressure photoluminescence data are reanalyzed and are found to be qualitatively consistent with the XRD data. This paper provides an example of how the helical π-conjugated backbone structure can be controlled by applying high quasihydrostatic pressure without modifications in its chemical structure. Moreover, it paves the way for wider use of high-pressure x-ray scattering in the research of π-conjugated polymers.
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Affiliation(s)
- M Knaapila
- Physics Department, Institute for Energy Technology, Kjeller NO-2027, Norway.
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Takizawa K, Wakita J, Sekiguchi K, Ando S. Variations in Aggregation Structures and Fluorescence Properties of a Semialiphatic Fluorinated Polyimide Induced by Very High Pressure. Macromolecules 2012. [DOI: 10.1021/ma300497a] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kazuhiro Takizawa
- Department
of Chemistry and Materials Science, Tokyo Institute of Technology, Ookayama, Meguro-ku,
Tokyo 152-8552, Japan
| | - Junji Wakita
- Department
of Chemistry and Materials Science, Tokyo Institute of Technology, Ookayama, Meguro-ku,
Tokyo 152-8552, Japan
| | - Kenji Sekiguchi
- Department
of Chemistry and Materials Science, Tokyo Institute of Technology, Ookayama, Meguro-ku,
Tokyo 152-8552, Japan
| | - Shinji Ando
- Department
of Chemistry and Materials Science, Tokyo Institute of Technology, Ookayama, Meguro-ku,
Tokyo 152-8552, Japan
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Knaapila M, Stepanyan R, Haase D, Carlson S, Torkkeli M, Cerenius Y, Scherf U, Guha S. Evidence for structural transition in hairy-rod poly[9,9-bis(2-ethylhexyl)fluorene] under high pressure conditions. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2010; 82:051803. [PMID: 21230493 DOI: 10.1103/physreve.82.051803] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Indexed: 05/30/2023]
Abstract
We report on an x-ray scattering experiment of bulk poly[9,9-bis(2-ethylhexyl)fluorene] under quasihydrostatic pressure from 1 to 11 GPa at room temperature. The scattering pattern of high molecular weight (HMW) polyfluorene (>10 kg/mol) undergoes significant changes between 2 and 4 GPa in the bulk phase. The 110 reflection of the hexagonal unit cell disappears, indicating a change in equatorial intermolecular order. The intensity of the 00 21 reflection drops, with a sudden move toward higher scattering angles. Beyond these pressures, the diminished 00 21 reflection tends to return toward lower angles. These changes may be interpreted as a transition from crystalline hexagonal to glassy nematic phase (perceiving order only in one direction). This transition may be rationalized by density arguments and the underlying theory of phase behavior of hairy-rod polyfluorene. Also the possible alteration of the 21-helical main chain toward more planar main chain conformation is discussed. The scattering of low molecular weight polyfluorene (<10 kg/mol) , which is glassy nematic in ambient pressure, is reminiscent with that of HMW polymer above 2-4 GPa.
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Affiliation(s)
- M Knaapila
- Physics Department, Institute for Energy Technology, NO-2027 Kjeller, Norway and MAX-lab, Lund University, SE-22100 Lund, Sweden.
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