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Greißel PM, Thiel D, Gotfredsen H, Chen L, Krug M, Papadopoulos I, Miskolzie M, Torres T, Clark T, Brøndsted Nielsen M, Tykwinski RR, Guldi DM. Intramolecular Triplet Diffusion Facilitates Triplet Dissociation in a Pentacene Hexamer. Angew Chem Int Ed Engl 2024; 63:e202315064. [PMID: 38092707 DOI: 10.1002/anie.202315064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Indexed: 01/26/2024]
Abstract
Triplet dynamics in singlet fission depend strongly on the strength of the electronic coupling. Covalent systems in solution offer precise control over such couplings. Nonetheless, efficient free triplet generation remains elusive in most systems, as the intermediate triplet pair 1 (T1 T1 ) is prone to triplet-triplet annihilation due to its spatial confinement. In the solid state, entropically driven triplet diffusion assists in the spatial separation of triplets, resulting in higher yields of free triplets. Control over electronic coupling in the solid state is, however, challenging given its sensitivity to molecular packing. We have thus developed a hexameric system (HexPnc) to enable solid-state-like triplet diffusion at the molecular scale. This system is realized by covalently tethering three pentacene dimers to a central subphthalocyanine scaffold. Transient absorption spectroscopy, complemented by theoretical structural optimizations and steady-state spectroscopy, reveals that triplet diffusion is indeed facilitated due to intramolecular cluster formation. The yield of free triplets in HexPnc is increased by a factor of up to 14 compared to the corresponding dimeric reference (DiPnc). Thus, HexPnc establishes crucial design aspects for achieving efficient triplet dissociation in strongly coupled systems by providing avenues for diffusive separation of 1 (T1 T1 ), while, concomitantly, retaining strong interchromophore coupling which preserves rapid formation of 1 (T1 T1 ).
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Affiliation(s)
- Phillip M Greißel
- Department of Chemistry and Pharmacy &, Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-University Erlangen-Nuremberg, Egerlandstraße 3, 91058, Erlangen, Germany
| | - Dominik Thiel
- Department of Chemistry and Pharmacy &, Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-University Erlangen-Nuremberg, Egerlandstraße 3, 91058, Erlangen, Germany
| | - Henrik Gotfredsen
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, T6G 2G2, Canada
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen Ø, Denmark
- Current address: Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford, OX1 3TA, UK
| | - Lan Chen
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, T6G 2G2, Canada
| | - Marcel Krug
- Department of Chemistry and Pharmacy &, Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-University Erlangen-Nuremberg, Egerlandstraße 3, 91058, Erlangen, Germany
| | - Ilias Papadopoulos
- Department of Chemistry and Pharmacy &, Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-University Erlangen-Nuremberg, Egerlandstraße 3, 91058, Erlangen, Germany
- Department of Applied Chemistry, Graduate School of Engineering, Center for Molecular Systems (CMS), Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Mark Miskolzie
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, T6G 2G2, Canada
| | - Tomás Torres
- Department of Organic Chemistry, Institute for Advanced Research in Chemical Sciences (IAdChem), Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain
- IMDEA Nanociencia, C/Faraday 9, Cantoblanco, 28049, Madrid, Spain
| | - Timothy Clark
- Department of Chemistry and Pharmacy &, Computer-Chemie-Center (CCC), Friedrich-Alexander-University Erlangen-Nuremberg, Nägelsbachstraße 25, 91052, Erlangen, Germany
| | - Mogens Brøndsted Nielsen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen Ø, Denmark
| | - Rik R Tykwinski
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, T6G 2G2, Canada
| | - Dirk M Guldi
- Department of Chemistry and Pharmacy &, Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-University Erlangen-Nuremberg, Egerlandstraße 3, 91058, Erlangen, Germany
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Gotfredsen H, Thiel D, Greißel PM, Chen L, Krug M, Papadopoulos I, Ferguson MJ, Nielsen MB, Torres T, Clark T, Guldi DM, Tykwinski RR. Sensitized Singlet Fission in Rigidly Linked Axial and Peripheral Pentacene-Subphthalocyanine Conjugates. J Am Chem Soc 2023; 145:9548-9563. [PMID: 37083447 DOI: 10.1021/jacs.2c13353] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
Abstract
The goal of harnessing the theoretical potential of singlet fission (SF), a process in which one singlet excited state is split into two triplet excited states, has become a central challenge in solar energy research. Covalently linked dimers provide crucial models for understanding the role of chromophore arrangement and coupling in SF. Sensitizers can be integrated into these systems to expand the absorption bandwidth through which SF can be accessed. Here, we define the role of the sensitizer-chromophore geometry in a sensitized SF model system. To this end, two conjugates have been synthesized consisting of a pentacene dimer (SF motif) connected via a rigid alkynyl bridge to a subphthalocyanine (the sensitizer motif) in either an axial or a peripheral arrangement. Steady-state and time-resolved photophysical measurements are used to confirm that both conjugates operate as per design, displaying near unity energy transfer efficiencies and high triplet quantum yields from SF. Decisively, energy transfer between the subphthalocyanine and pentacene dimer occurs ca. 26 times faster in the peripheral conjugate, even though the two chromophores are ca. 3 Å farther apart than in the axial conjugate. Following a theoretical evaluation of the dipolar coupling, Vdip2, and the orientation factor, κ2, of both the axial (Vdip2 = 140 cm-2; κ2 = 0.08) and the peripheral (Vdip2 = 724 cm-2; κ2 = 1.46) arrangements, we establish that this rate acceleration is due to a more favorable (nearly co-planar) relative orientation of the transition dipole moments of the subphthalocyanine and pentacenes in the peripheral constellation.
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Affiliation(s)
- Henrik Gotfredsen
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, Copenhagen Ø 2100, Denmark
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford OX1 3TA, U.K
| | - Dominik Thiel
- Department of Chemistry and Pharmacy and Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-University Erlangen-Nuremberg, Egerlandstraße 3, 91058 Erlangen, Germany
| | - Phillip M Greißel
- Department of Chemistry and Pharmacy and Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-University Erlangen-Nuremberg, Egerlandstraße 3, 91058 Erlangen, Germany
| | - Lan Chen
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
| | - Marcel Krug
- Department of Chemistry and Pharmacy and Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-University Erlangen-Nuremberg, Egerlandstraße 3, 91058 Erlangen, Germany
| | - Ilias Papadopoulos
- Department of Chemistry and Pharmacy and Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-University Erlangen-Nuremberg, Egerlandstraße 3, 91058 Erlangen, Germany
- Department of Applied Chemistry, Graduate School of Engineering, Center for Molecular Systems (CMS), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka819-0395, Japan
| | - Michael J Ferguson
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
| | - Mogens Brøndsted Nielsen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, Copenhagen Ø 2100, Denmark
| | - Tomás Torres
- Department of Organic Chemistry and Institute for Advanced Research in Chemical Sciences (IAdChem), Universidad Autónoma de Madrid, Campus de Cantoblanco, Madrid 28049, Spain
- IMDEA Nanociencia, C/Faraday 9, Cantoblanco, Madrid 28049, Spain
| | - Timothy Clark
- Department of Chemistry and Pharmacy and Computer-Chemie-Center (CCC), Friedrich-Alexander-University Erlangen-Nuremberg, Nägelsbachstraße 25, Erlangen 91052, Germany
| | - Dirk M Guldi
- Department of Chemistry and Pharmacy and Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-University Erlangen-Nuremberg, Egerlandstraße 3, 91058 Erlangen, Germany
| | - Rik R Tykwinski
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
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Wang T, Zhang BY, Zhang HL. Singlet Fission Materials for Photovoltaics: from Small Molecules to Macromolecules. Macromol Rapid Commun 2022; 43:e2200326. [PMID: 35703581 DOI: 10.1002/marc.202200326] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 05/29/2022] [Indexed: 11/08/2022]
Abstract
Singlet fission (SF) is a spin-allowed process in which a singlet state splits into two triplet states. Materials that enable SF have attracted great attention in the last decade, mainly stemming from the potential of overcoming the Shockley-Queisser (SQ) limit in photoenergy conversion. In the past decade, a large number of new molecules exhibiting SF have been explored and many devices based on SF materials have been studied, though the mechanistic understanding is still obscure. This review focuses on the recent developments of SF materials, including small molecules, oligomers and polymers. The molecular design strategies and related mechanisms of SF are discussed. Then the dynamics of charge transfer and energy transfer between SF materials and other materials are introduced. Further, we discuss the progresses of implementing SF in photovoltaics. It is hoped that a comprehensive understanding to the SF materials, devices and mechanism may pave a new way for the design of next generation photovoltaics. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Ting Wang
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), Key Laboratory of Special Function Materials and Structure Design, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, P. R. China
| | - Bo-Yang Zhang
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), Key Laboratory of Special Function Materials and Structure Design, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, P. R. China
| | - Hao-Li Zhang
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), Key Laboratory of Special Function Materials and Structure Design, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, P. R. China.,Prof. H. L. Zhang, Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin, 300072, P. R. China
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Singh G, Chandra S. Unravelling the structural‐property relations of porphyrinoids with respect to photo‐ and electro‐chemical activities. ELECTROCHEMICAL SCIENCE ADVANCES 2021. [DOI: 10.1002/elsa.202100149] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Affiliation(s)
- Gita Singh
- School of Chemistry University College Dublin Dublin 4 Ireland
| | - Sudeshna Chandra
- Department of Chemistry Sunandan Divatia School of Science SVKM's NMIMS (Deemed to be) University Mumbai India
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Manna B, Nandi A, Vats BG. Role of nanosize and defect trapping upon singlet fission yield and singlet fission dynamics of 1,6-Diphenyl-1,3,5-hexatriene nanoaggregates. J Photochem Photobiol A Chem 2021. [DOI: 10.1016/j.jphotochem.2021.113262] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Medina DP, Fernández-Ariza J, Urbani M, Sauvage F, Torres T, Rodríguez-Morgade MS. Tuning the Acceptor Unit of Push-Pull Porphyrazines for Dye-Sensitized Solar Cells. Molecules 2021; 26:molecules26082129. [PMID: 33917225 PMCID: PMC8068076 DOI: 10.3390/molecules26082129] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 03/19/2021] [Accepted: 03/30/2021] [Indexed: 11/18/2022] Open
Abstract
A family of four push–pull porphyrazines of A3B type, where each unit A contains two peripheral propyl chains and the unit B is endowed with a carboxylic acid, were prepared. The carboxylic acid was attached to the β-position of the pyrrolic unit, either directly (Pz 10), or through cyanovinyl (Pz 11) and phenyl (Pz 7) groups. The fourth Pz (14) consisted in a pyrazinoporphyrazine wherein the dinitrogenated heterocycle provided intrinsic donor–acceptor character to the macrocycle and contained a carboxyphenyl substituent. The direct attachment of the carboxylic acid functions and their linkers to the porphyrazine core produces stronger perturbation on the electronic properties of the macrocycle, with respect to their connection through fused benzene or pyrazine rings in TT112 and 14, respectively. The HOMO and LUMO energies of the Pzs, which were estimated with DFT calculations, show little variation within the series, except upon introduction of the cyanovinyl spacer, which produces a decrease in both frontier orbital energetic levels. This effective interaction of cyanovinyl substitution with the macrocycle is also evidenced in UV/Vis spectroscopy, where a large splitting of the Q-band indicates strong desymmetrization of the Pz. The performance of the four Pzs as photosensitizers in DSSCs were also investigated.
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Affiliation(s)
- Diana-Paola Medina
- Departamento de Química Orgánica, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain; (D.-P.M.); (J.F.-A.)
| | - Javier Fernández-Ariza
- Departamento de Química Orgánica, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain; (D.-P.M.); (J.F.-A.)
| | - Maxence Urbani
- Instituto Madrileño de Estudios Avanzados (IMDEA)-Nanociencia, c/ Faraday, 9, Cantoblanco, 28049 Madrid, Spain;
| | - Frédéric Sauvage
- Laboratoire de Réactivité et Chimie des Solides, Université de Picardie Jules Verne, CNRS UMR7314, Hub de L’énergie, 15 rue Baudelocque, 80039 Amiens, France;
| | - Tomás Torres
- Departamento de Química Orgánica, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain; (D.-P.M.); (J.F.-A.)
- Instituto Madrileño de Estudios Avanzados (IMDEA)-Nanociencia, c/ Faraday, 9, Cantoblanco, 28049 Madrid, Spain;
- Correspondence: (T.T.); (M.S.R.-M.)
| | - M. Salomé Rodríguez-Morgade
- Departamento de Química Orgánica, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain; (D.-P.M.); (J.F.-A.)
- Correspondence: (T.T.); (M.S.R.-M.)
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Bottari G, de la Torre G, Guldi DM, Torres T. An exciting twenty-year journey exploring porphyrinoid-based photo- and electro-active systems. Coord Chem Rev 2021. [DOI: 10.1016/j.ccr.2020.213605] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Guzmán D, Papadopoulos I, Lavarda G, Rami PR, Tykwinski RR, Rodríguez‐Morgade MS, Guldi DM, Torres T. Controlling Intramolecular Förster Resonance Energy Transfer and Singlet Fission in a Subporphyrazine-Pentacene Conjugate by Solvent Polarity. Angew Chem Int Ed Engl 2021; 60:1474-1481. [PMID: 33002284 PMCID: PMC7839765 DOI: 10.1002/anie.202011197] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Indexed: 11/24/2022]
Abstract
Due its complementary absorptions in the range of 450 and 600 nm, an energy-donating hexaaryl-subporphyrazine has been linked to a pentacene dimer, which acts primarily as an energy acceptor and secondarily as a singlet fission enabler. In the corresponding conjugate, efficient intramolecular Förster resonance energy transfer (i-FRET) is the modus operandi to transfer energy from the subporphyrazine to the pentacene dimer. Upon energy transfer, the pentacene dimer undergoes intramolecular singlet fission (i-SF), that is, converting the singlet excited state, via an intermediate state, into a pair of correlated triplet excited states. Solvatochromic fluorescence of the subporphyrazine is a key feature of this system and features a red-shift as large as 20 nm in polar media. Solvent is thus used to modulate spectral overlap between the fluorescence of subporphyrazine and absorption of the pentacene dimer, which controls the Förster rate constant, on one hand, and the triplet quantum yield, on the other hand. The optimum spectral overlap is realized in xylene, leading to Förster rate constant of 3.52×1011 s-1 and a triplet quantum yield of 171 % ±10 %. In short, the solvent polarity dependence, which is a unique feature of subporphyrazines, is decisive in terms of adjusting spectral overlap, ensuring a sizable Förster rate constant, and maximizing triplet quantum yields. Uniquely, this optimization can be achieved without a need for synthetic modification of the subporphyrazine donor.
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Affiliation(s)
- David Guzmán
- Departamento de Química OrgánicaUniversidad Autónoma de MadridCantoblanco28049MadridSpain
| | - Ilias Papadopoulos
- Department of Chemistry and PharmacyInterdisciplinary Center for Molecular Materials (ICMM)Friedrich-Alexander-Universität Erlangen-NürnbergEgerlandstr. 391058ErlangenGermany
| | - Giulia Lavarda
- Departamento de Química OrgánicaUniversidad Autónoma de MadridCantoblanco28049MadridSpain
| | - Parisa R. Rami
- Department of ChemistryUniversity of AlbertaEdmontonAlbertaT6G 2G2Canada
| | - Rik R. Tykwinski
- Department of ChemistryUniversity of AlbertaEdmontonAlbertaT6G 2G2Canada
| | - M. Salomé Rodríguez‐Morgade
- Departamento de Química OrgánicaUniversidad Autónoma de MadridCantoblanco28049MadridSpain
- Institute for Advanced Research in Chemical Sciences (IAdChem)Universidad Autónoma de MadridCantoblanco28049MadridSpain
| | - Dirk M. Guldi
- Department of Chemistry and PharmacyInterdisciplinary Center for Molecular Materials (ICMM)Friedrich-Alexander-Universität Erlangen-NürnbergEgerlandstr. 391058ErlangenGermany
| | - Tomás Torres
- Departamento de Química OrgánicaUniversidad Autónoma de MadridCantoblanco28049MadridSpain
- IMDEA-NanocienciaCampus de Cantoblanco28049MadridSpain
- Institute for Advanced Research in Chemical Sciences (IAdChem)Universidad Autónoma de MadridCantoblanco28049MadridSpain
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Guzmán D, Papadopoulos I, Lavarda G, Rami PR, Tykwinski RR, Rodríguez‐Morgade MS, Guldi DM, Torres T. Kontrolle des intramolekularen Förster‐Resonanzenergietransfers und der Singulettspaltung in einem Subporphyrazin‐Pentacen‐Konjugat mittels Lösungsmittelpolarität. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202011197] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- David Guzmán
- Departamento de Química Orgánica Universidad Autónoma de Madrid Cantoblanco 28049 Madrid Spanien
| | - Ilias Papadopoulos
- Department of Chemistry and Pharmacy Interdisciplinary Center for Molecular Materials (ICMM) Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstr. 3 91058 Erlangen Deutschland
| | - Giulia Lavarda
- Departamento de Química Orgánica Universidad Autónoma de Madrid Cantoblanco 28049 Madrid Spanien
| | - Parisa R. Rami
- Department of Chemistry University of Alberta Edmonton Alberta T6G 2G2 Kanada
| | - Rik R. Tykwinski
- Department of Chemistry University of Alberta Edmonton Alberta T6G 2G2 Kanada
| | - M. Salomé Rodríguez‐Morgade
- Departamento de Química Orgánica Universidad Autónoma de Madrid Cantoblanco 28049 Madrid Spanien
- Institute for Advanced Research in Chemical Sciences (IAdChem) Universidad Autónoma de Madrid Cantoblanco 28049 Madrid Spanien
| | - Dirk M. Guldi
- Department of Chemistry and Pharmacy Interdisciplinary Center for Molecular Materials (ICMM) Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstr. 3 91058 Erlangen Deutschland
| | - Tomás Torres
- Departamento de Química Orgánica Universidad Autónoma de Madrid Cantoblanco 28049 Madrid Spanien
- IMDEA-Nanociencia Campus de Cantoblanco 28049 Madrid Spanien
- Institute for Advanced Research in Chemical Sciences (IAdChem) Universidad Autónoma de Madrid Cantoblanco 28049 Madrid Spanien
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R S L, Kurup GB, Vennapusa SR. Identification of a receiver triplet state in the ultrafast intersystem crossing of carbonylpyrenes. Phys Chem Chem Phys 2020; 22:6145-6153. [PMID: 32124884 DOI: 10.1039/c9cp06857k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The near-unity triplet quantum yield of photoexcited carbonyl functionalized pyrenes is theoretically investigated. The estimated energetics of singlet-triplet manifolds and relevant spin-orbit coupling parameters strongly suggest triplet state formation via the S1→ T4/T5 pathway. Quantum wavepacket dynamics of triplet manifolds within the linear vibronic coupling approach reveal that the receiver triplet state would undergo rapid internal conversion decay to the lower triplet state(s), facilitating efficient triplet generation by minimizing the reverse intersystem crossing possibilities. On the basis of these results, a unified mechanism is proposed to describe the ultrafast intersystem crossing process in these molecules.
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Affiliation(s)
- Lekshmi R S
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM), Maruthamala P.O., Vithura, Thiruvananthapuram 695551, Kerala, India.
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