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Nair AG, Das A, Chathoth NE, Pratim Sarmah M, Anjukandi P. Chemical Tailoring Assisted non-TADF to TADF Switching in Carbazole-Benzophenone Emitter - An In-silico Investigation. Chemphyschem 2023; 24:e202300445. [PMID: 37608522 DOI: 10.1002/cphc.202300445] [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: 06/24/2023] [Revised: 08/22/2023] [Accepted: 08/22/2023] [Indexed: 08/24/2023]
Abstract
Organic light-emitting diodes (OLEDs) have become one of the most popular lighting technologies since they offer several advantages over conventional devices. In carbazole-benzophenone (CzBP) OLED devices, the polymeric form of the compound is previously reported to be Thermally Activated Delayed Fluorescence (TADF)-active (ΔEST ≈0.12 eV), while the monomer (CzBP) (ΔEST ≈0.39 eV) does not. The present study examines the effect of chemical tailoring on the optical and photophysical properties of CzBP using DFT and TDDFT methods. The introduction of a single -NO2 group or di-substitution (-NO2 , -COOH or -CN) in the selected LUMO region of the reference CzBP monomer significantly reduces ΔEST ≈0.01 eV, projecting these systems as potential TADF-active emitters. Furthermore, the chemical modification of CzBP-LUMO alters the two-step TADF mechanism (T1 →T2 →S1 ) in CzBP (ES₁ >ET2 >ET₁ ) to the Direct Singlet Harvesting (T1 →S1 ) mechanism (ET2 >ES₁ >ET₁ ), which has recently been identified in the fourth-generation OLED materials.
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Affiliation(s)
- Aparna G Nair
- Department of Chemistry, Indian Institute of Technology, Palakkad, Kerala, 678557, India
| | - Arathi Das
- Department of Chemistry, Pondicherry University, Kalapet, 605014, Puducherry, India
| | - Nayana Edavan Chathoth
- Department of Chemistry, Indian Institute of Technology, Palakkad, Kerala, 678557, India
| | - Manash Pratim Sarmah
- Department of Chemistry, Indian Institute of Technology, Palakkad, Kerala, 678557, India
| | - Padmesh Anjukandi
- Department of Chemistry, Indian Institute of Technology, Palakkad, Kerala, 678557, India
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Duda E, Madayanad Suresh S, Hall D, Bagnich S, Saxena R, Cordes DB, Slawin AMZ, Beljonne D, Olivier Y, Köhler A, Zysman-Colman E. An Oligomer Approach for Blue Thermally Activated Delayed Fluorescent Emitters Based on Twisted Donor-Acceptor Units. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2023; 35:2027-2037. [PMID: 36936179 PMCID: PMC10018739 DOI: 10.1021/acs.chemmater.2c03438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 02/14/2023] [Indexed: 06/18/2023]
Abstract
The development of efficient blue donor-acceptor thermally activated delayed fluorescence (TADF) emitters remains a challenge. To enhance the efficiency of TADF-related processes of the emitter, we targeted a molecular design that would introduce a large number of intermediate triplet states between the lowest energy excited triplet (T1) and singlet (S1) excited states. Here, we introduce an oligomer approach using repetitive donor-acceptor units to gradually increase the number of quasi-degenerate states. In our design, benzonitrile (BN) moieties were selected as acceptors that are connected together via the amine donors, acting as bridges to adjacent BN acceptors. To preserve the photoluminescence emission wavelength across the series, we employed a design based on an ortho substitution pattern of the donors about the BN acceptor that induces a highly twisted conformation of the emitters, limiting the conjugation. Via a systematic photophysical study, we show that increasing the oligomer size allows for enhancement of the intersystem crossing and reverse intersystem crossing rates. We attribute the increasing intersystem crossing rate to the increasing number of intermediate triplet states along the series, confirmed by the time-dependent density functional theory. Overall, we report an approach to enhance the efficiency of TADF-related processes without changing the blue photoluminescence color.
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Affiliation(s)
- Eimantas Duda
- Soft
Matter Optoelectronics, BIMF & BPI, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany
| | - Subeesh Madayanad Suresh
- Organic
Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews KY16 9ST, UK
| | - David Hall
- Organic
Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews KY16 9ST, UK
- Laboratory
for Chemistry of Novel Materials, Materials Research Institute, University of Mons, Place du Parc 20, 7000 Mons, Belgium
| | - Sergey Bagnich
- Soft
Matter Optoelectronics, BIMF & BPI, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany
| | - Rishabh Saxena
- Soft
Matter Optoelectronics, BIMF & BPI, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany
| | - David B. Cordes
- Organic
Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews KY16 9ST, UK
| | - Alexandra M. Z. Slawin
- Organic
Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews KY16 9ST, UK
| | - David Beljonne
- Laboratory
for Chemistry of Novel Materials, Materials Research Institute, University of Mons, Place du Parc 20, 7000 Mons, Belgium
| | - Yoann Olivier
- Laboratory
for Chemistry of Novel Materials, Materials Research Institute, University of Mons, Place du Parc 20, 7000 Mons, Belgium
- Unité
de Chimie Physique Théorique et Structurale & Laboratoire
de Physique du Solide, Namur Institute of Structured Matter, Université de Namur, Rue de Bruxelles, 61, 5000 Namur, Belgium
| | - Anna Köhler
- Soft
Matter Optoelectronics, BIMF & BPI, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany
| | - Eli Zysman-Colman
- Organic
Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews KY16 9ST, UK
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Lee S, Lee Y, Lee K, Lee S, Wang KK, Han WS. Effect of bulkiness on the triplet state of carbazole-benzophenone-based dyad systems. J Photochem Photobiol A Chem 2023. [DOI: 10.1016/j.jphotochem.2022.114347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Franceschini M, Crosta M, Ferreira RR, Poletto D, Demitri N, Zobel JP, González L, Bonifazi D. peri-Acenoacene Ribbons with Zigzag BN-Doped Peripheries. J Am Chem Soc 2022; 144:21470-21484. [DOI: 10.1021/jacs.2c06803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Marco Franceschini
- Institute of Organic Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 38, 1090, Vienna, Austria
| | - Martina Crosta
- Institute of Organic Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 38, 1090, Vienna, Austria
| | - Rúben R. Ferreira
- Institute of Organic Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 38, 1090, Vienna, Austria
| | - Daniele Poletto
- Institute of Organic Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 38, 1090, Vienna, Austria
| | - Nicola Demitri
- Elettra − Sincrotrone Trieste, S.S. 14 Km 163.5 in Area Science Park, 34149 Basovizza, Trieste, Italy
| | - J. Patrick Zobel
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 17, 1090, Vienna, Austria
| | - Leticia González
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 17, 1090, Vienna, Austria
| | - Davide Bonifazi
- Institute of Organic Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 38, 1090, Vienna, Austria
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Wu W, Liu B. Modulating the optical properties and functions of organic molecules through polymerization. MATERIALS HORIZONS 2022; 9:99-111. [PMID: 34498024 DOI: 10.1039/d1mh01030a] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Organic functional materials with advanced optical properties have attracted much attention due to their broad applications, such as in light-emitting diodes, solar cells, anti-counterfeiting, photocatalysis, and even disease diagnosis and treatment. Recent research has revealed that many optical properties of organic molecules can be improved through simple polymerization. In this review, we discuss the phenomenon, mechanism, and impact of polymerization on the properties of materials, including the polymerization-induced spectral shift, polymerization-enhanced photosensitization, polymerization-enhanced two-photon absorption, polymerization-enhanced photocatalytic efficiency, polymerization-induced room temperature phosphorescence, polymerization-induced thermally activated delayed fluorescence, and polymerization-induced emission using specific examples with different applications. The new opportunities arising from polymerization in designing high performance optical materials are summarized in the future perspective.
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Affiliation(s)
- Wenbo Wu
- Institute of Molecular Aggregation Science, Tianjin University, Tianjin 300072, China.
| | - Bin Liu
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585, Singapore.
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou 350207, China
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Cheng J, Zhou Y, Xu S, Xie Y, Mao D, Wu W, Li Z. From main chain conjugated polymer photosensitizer to hyperbranched one: the expansion of polymerization-enhanced photosensitization effect for photodynamic therapy. J Mater Chem B 2022; 10:5008-5015. [DOI: 10.1039/d2tb00679k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Three conjugated polymers with the same donor-acceptor structure but totally different architectures are design to show both Type-I and Type-II photosensitization abilities simultaneously, among which the hyperbranched polymer shows the...
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