1
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Lin LC, Dill RD, Thorley KJ, Parkin SR, Anthony JE, Johnson JC, Damrauer NH. Revealing the Singlet Fission Mechanism for a Silane-Bridged Thienotetracene Dimer. J Phys Chem A 2024; 128:3982-3992. [PMID: 38717589 PMCID: PMC11129308 DOI: 10.1021/acs.jpca.4c01463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 04/25/2024] [Accepted: 04/26/2024] [Indexed: 05/24/2024]
Abstract
Tetraceno[2,3-b]thiophene is regarded as a strong candidate for singlet fission-based solar cell applications due to its mixed characteristics of tetracene and pentacene that balance exothermicity and triplet energy. An electronically weakly coupled tetraceno[2,3-b]thiophene dimer (Et2Si(TIPSTT)2) with a single silicon atom bridge has been synthesized, providing a new platform to investigate the singlet fission mechanism involving the two acene chromophores. We study the excited state dynamics of Et2Si(TIPSTT)2 by monitoring the evolution of multiexciton coupled triplet states, 1TT to 5TT to 3TT to T1 + S0, upon photoexcitation with transient absorption, temperature-dependent transient absorption, and transient/pulsed electron paramagnetic resonance spectroscopies. We find that the photoexcited singlet lifetime is 107 ps, with 90% evolving to form the TT state, and the complicated evolution between the multiexciton states is unraveled, which can be an important reference for future efforts toward tetraceno[2,3-b]thiophene-based singlet fission solar cells.
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Affiliation(s)
- Liang-Chun Lin
- Department
of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Ryan D. Dill
- Department
of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Karl J. Thorley
- Department
of Chemistry & Center for Applied Energy Research, University of Kentucky, Lexington, Kentucky 40506-0055, United States
| | - Sean R. Parkin
- Department
of Chemistry & Center for Applied Energy Research, University of Kentucky, Lexington, Kentucky 40506-0055, United States
| | - John E. Anthony
- Department
of Chemistry & Center for Applied Energy Research, University of Kentucky, Lexington, Kentucky 40506-0055, United States
| | - Justin C. Johnson
- National
Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
- Renewable
and Sustainable Energy Institute (RASEI), University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Niels H. Damrauer
- Department
of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
- Renewable
and Sustainable Energy Institute (RASEI), University of Colorado Boulder, Boulder, Colorado 80309, United States
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2
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Pompetti N, Smyser KE, Feingold B, Owens R, Lama B, Sharma S, Damrauer NH, Johnson JC. Tetracene Diacid Aggregates for Directing Energy Flow toward Triplet Pairs. J Am Chem Soc 2024; 146. [PMID: 38606884 PMCID: PMC11046478 DOI: 10.1021/jacs.4c02058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 03/27/2024] [Accepted: 03/28/2024] [Indexed: 04/13/2024]
Abstract
A comprehensive investigation of the solution-phase photophysics of tetracene bis-carboxylic acid [5,12-tetracenepropiolic acid (Tc-DA)] and its related methyl ester [5,12-tetracenepropynoate (Tc-DE)], a non-hydrogen-bonding counterpart, reveals the role of the carboxylic acid moiety in driving molecular aggregation and concomitant excited-state behavior. Low-concentration solutions of Tc-DA exhibit similar properties to the popular 5,12-bis((triisopropylsilyl)ethynl)tetracene, but as the concentration increases, evidence for aggregates that form excimers and a new mixed-state species with charge-transfer (CT) and correlated triplet pair (TT) character is revealed by transient absorption and fluorescence experiments. Aggregates of Tc-DA evolve further with concentration toward an additional phase that is dominated by the mixed CT/TT state which is the only state present in Tc-DE aggregates and can be modulated with the solvent polarity. Computational modeling finds that cofacial arrangement of Tc-DA and Tc-DE subunits is the most stable aggregate structure and this agrees with results from 1H NMR spectroscopy. The calculated spectra of these cofacial dimers replicate the observed broadening in ground-state absorption as well as accurately predict the formation of a near-UV transition associated with a CT between molecular subunits that is unique to the specific aggregate structure. Taken together, the results suggest that the hydrogen bonding between Tc-DA molecules and the associated disruption of hydrogen bonding with solvent produce a regime of dimer-like behavior, absent in Tc-DE, that favors excimers rather than CT/TT mixed states. The control of aggregate size and structure using distinct functional groups, solute concentration, and solvent in tetracene promises new avenues for its use in light-harvesting schemes.
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Affiliation(s)
- Nicholas
F. Pompetti
- National
Renewable Energy Laboratory, 15013 Denver West Pkwy, Golden, Colorado 80401, United States
- University
of Colorado, Boulder, Colorado 80401, United States
| | - Kori E. Smyser
- University
of Colorado, Boulder, Colorado 80401, United States
| | | | - Raythe Owens
- University
of Colorado, Boulder, Colorado 80401, United States
| | - Bimala Lama
- University
of Colorado, Boulder, Colorado 80401, United States
| | - Sandeep Sharma
- University
of Colorado, Boulder, Colorado 80401, United States
| | - Niels H. Damrauer
- University
of Colorado, Boulder, Colorado 80401, United States
- Renewable
and Sustainable Energy Institute, University
of Colorado Boulder, Boulder, Colorado 80401, United States
| | - Justin C. Johnson
- National
Renewable Energy Laboratory, 15013 Denver West Pkwy, Golden, Colorado 80401, United States
- Renewable
and Sustainable Energy Institute, University
of Colorado Boulder, Boulder, Colorado 80401, United States
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3
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Gilligan AT, Owens R, Miller EG, Pompetti NF, Damrauer NH. Enhancing NIR-to-visible upconversion in a rigidly coupled tetracene dimer: approaching statistical limits for triplet-triplet annihilation using intramolecular multiexciton states. Chem Sci 2024; 15:1283-1296. [PMID: 38274080 PMCID: PMC10806848 DOI: 10.1039/d3sc04795d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 12/11/2023] [Indexed: 01/27/2024] Open
Abstract
Important applications of photon upconversion through triplet-triplet annihilation require conversion of near-IR photons to visible light. Generally, however, efficiencies in this spectral region lag behind bluer analogues. Herein we consider potential benefits from a conformationally well-defined covalent dimer annihilator TIPS-BTX in studies that systematically compare function to a related monomer model TIPS-tetracene (TIPS-Tc). TIPS-BTX exhibits weak electronic coupling between chromophores juxtaposed about a polycyclic bridge. We report an upconversion yield ϕUC for TIPS-BTX that is more than 20× larger than TIPS-Tc under comparable conditions (0.16%). While the dimer ϕUC is low compared to bluer champion systems, this yield is amongst the largest so-far reported for a tetracenic dimer system and is achieved under unoptimized conditions suggesting a significantly higher ceiling. Further investigation shows the ϕUC enhancement for the dimer is due exclusively to the TTA process with an effective yield more that 30× larger for TIPS-BTX compared to TIPS-Tc. The ϕTTA enhancement for TIPS-BTX relative to TIPS-Tc is indicative of participation by intramolecular multiexciton states with evidence presented in spin statistical arguments that the 5TT is involved in productive channels. For TIPS-BTX we report a spin-statistical factor f = 0.42 that matches or exceeds values found in champion annihilator systems such as DPA. At the same time, the poor relative efficiency of TIPS-Tc suggests involvement of non-productive bimolecular channels and excimeric states are suspected. Broadly these studies indicate that funneling of photogenerated electronic states into productive pathways, and avoiding parasitic ones, remains central to the development of champion upconversion systems.
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Affiliation(s)
- Alexander T Gilligan
- Department of Chemistry, University of Colorado Boulder Boulder Colorado 80309 USA
| | - Raythe Owens
- Department of Chemistry, University of Colorado Boulder Boulder Colorado 80309 USA
| | - Ethan G Miller
- Department of Chemistry, University of Colorado Boulder Boulder Colorado 80309 USA
| | - Nicholas F Pompetti
- Department of Chemistry, University of Colorado Boulder Boulder Colorado 80309 USA
| | - Niels H Damrauer
- Department of Chemistry, University of Colorado Boulder Boulder Colorado 80309 USA
- Renewable and Sustainable Energy Institute (RASEI), University of Colorado Boulder Boulder Colorado 80309 USA
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4
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Pradhan E, Zeng T. The Lack of Triplet Fusion for an Intramolecular Singlet Fission Chromophore: The Expected, the Unexpected, and a Reconciliation. J Phys Chem Lett 2024; 15:43-50. [PMID: 38127796 DOI: 10.1021/acs.jpclett.3c03238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
Singlet fission (SF) has the potential to play a key role in photovoltaics since it generates a larger number of longer-lived triplet excitons after photoabsorption. Intramolecular SF (iSF) is of special interest since it enables tuning of SF efficiency by adjusting interchromophore configuration through covalent interaction. However, as elaborated in the present work, iSF chromophores are doomed to dissatisfy one general thermodynamic criterion for all SF chromophores, intramolecular or not: E(T2) ≥ 2E(T1), and therefore, the fusion of two triplet excitons to one triplet exciton is thermodynamically favorable. In our nonadiabatic quantum dynamics simulation for a model iSF chromophore, this expected fusion does not occur, because of the inefficient intersystem crossing hidden under the cover of internal conversion of the triplet fusion. A reconciliation is achieved between the dissatisfaction of E(T2) ≥ 2E(T1) and the large tetraradical character for general iSF chromophores.
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Affiliation(s)
- Ekadashi Pradhan
- Department of Chemistry, York University, Toronto, Ontario M3J1P3, Canada
| | - Tao Zeng
- Department of Chemistry, York University, Toronto, Ontario M3J1P3, Canada
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5
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Bhattacharyya A, Sahu A, Patra S, Tiwari V. Low- and high-frequency vibrations synergistically enhance singlet exciton fission through robust vibronic resonances. Proc Natl Acad Sci U S A 2023; 120:e2310124120. [PMID: 38019862 PMCID: PMC10710028 DOI: 10.1073/pnas.2310124120] [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: 06/19/2023] [Accepted: 10/14/2023] [Indexed: 12/01/2023] Open
Abstract
Singlet exciton fission (SEF) is initiated by ultrafast internal conversion of a singlet exciton into a correlated triplet pair [Formula: see text]. The "reaction coordinates" for ultrafast SEF even in archetypal systems such as pentacene thin film remain unclear. Couplings between fast electrons and slow nuclei are ubiquitous across a range of phenomena in chemistry. Accordingly, spectroscopic detection of vibrational coherences in the [Formula: see text] photoproduct motivated investigations into a possible role of vibronic coupling, akin to that reported in several photosynthetic proteins. However, acenes are very different from chlorophylls with 10× larger vibrational displacements upon photoexcitation and low-frequency vibrations modulating intermolecular orbital overlaps. Whether (and if so how) these unique features carry any mechanistic significance for SEF remains a poorly understood question. Accordingly, synthetic design of new molecules aiming to mimic this process across the solar spectrum has broadly relied on tuning electronic couplings. We address this gap and identify previously unrecognized synergistic interplay of vibrations, which in striking contrast to photosynthesis, vitally enhances SEF across a broad, nonselective and, therefore, unavoidable range of vibrational frequencies. We argue that attaching mechanistic significance to spectroscopically observed prominent quantum beats is misleading. Instead, we show that vibronic mixing leads to anisotropic quantum beats and propose readily implementable polarization-based two-dimensional electronic spectroscopy experiments which uniquely distinguish vibrations which drive vibronic mixing and promote SEF, against spectator vibrations simply accompanying ultrafast internal conversion. Our findings introduce crucial ingredients in synthetic design of SEF materials and spectroscopy experiments aiming to decipher mechanistic details from quantum beats.
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Affiliation(s)
- Atandrita Bhattacharyya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore560012, India
| | - Amitav Sahu
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore560012, India
| | - Sanjoy Patra
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore560012, India
| | - Vivek Tiwari
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore560012, India
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6
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Lin LC, Smith T, Ai Q, Rugg BK, Risko C, Anthony JE, Damrauer NH, Johnson JC. Multiexciton quintet state populations in a rigid pyrene-bridged parallel tetracene dimer. Chem Sci 2023; 14:11554-11565. [PMID: 37886089 PMCID: PMC10599476 DOI: 10.1039/d3sc03153e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 10/01/2023] [Indexed: 10/28/2023] Open
Abstract
The multiexciton quintet state, 5TT, generated as a singlet fission intermediate in pairs of molecular chromophores, is a promising candidate as a qubit or qudit in future quantum information science schemes. In this work, we synthesize a pyrene-bridged parallel tetracene dimer, TPT, with an optimized interchromophore coupling strength to prevent the dissociation of 5TT to two decorrelated triplet (T1) states, which would contaminate the spin-state mixture. Long-lived and strongly spin-polarized pure 5TT state population is observed via transient absorption spectroscopy and transient/pulsed electron paramagnetic resonance spectroscopy, and its lifetime is estimated to be >35 µs, with the dephasing time (T2) for the 5TT-based qubit measured to be 726 ns at 10 K. Direct relaxation from 1TT to the ground state does diminish the overall excited state population, but the exclusive 5TT population at large enough persistent density for pulsed echo determination of spin coherence time is consistent with recent theoretical models that predict such behavior for strict parallel chromophore alignment and large exchange coupling.
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Affiliation(s)
- Liang-Chun Lin
- Department of Chemistry, University of Colorado Boulder Boulder CO 80309 USA
| | - Tanner Smith
- Department of Chemistry & Center for Applied Energy Research, University of Kentucky Lexington Kentucky 40506-0055 USA
| | - Qianxiang Ai
- Department of Chemistry & Center for Applied Energy Research, University of Kentucky Lexington Kentucky 40506-0055 USA
| | - Brandon K Rugg
- National Renewable Energy Laboratory 15013 Denver West Parkway Golden Colorado 80401 USA
| | - Chad Risko
- Department of Chemistry & Center for Applied Energy Research, University of Kentucky Lexington Kentucky 40506-0055 USA
| | - John E Anthony
- Department of Chemistry & Center for Applied Energy Research, University of Kentucky Lexington Kentucky 40506-0055 USA
| | - Niels H Damrauer
- Department of Chemistry, University of Colorado Boulder Boulder CO 80309 USA
- Renewable and Sustainable Energy Institute (RASEI), University of Colorado Boulder Boulder CO 80309 USA
| | - Justin C Johnson
- National Renewable Energy Laboratory 15013 Denver West Parkway Golden Colorado 80401 USA
- Renewable and Sustainable Energy Institute (RASEI), University of Colorado Boulder Boulder CO 80309 USA
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7
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Majumder K, Mukherjee S, Panjwani NA, Lee J, Bittl R, Kim W, Patil S, Musser AJ. Controlling Intramolecular Singlet Fission Dynamics via Torsional Modulation of Through-Bond versus Through-Space Couplings. J Am Chem Soc 2023; 145:20883-20896. [PMID: 37705333 DOI: 10.1021/jacs.3c06075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/15/2023]
Abstract
Covalent dimers, particularly pentacenes, are the dominant platform for developing a mechanistic understanding of intramolecular singlet fission (iSF). Numerous studies have demonstrated that a photoexcited singlet state in these structures can rapidly and efficiently undergo exciton multiplication to form a correlated pair of triplets within a single molecule, with potential applications from photovoltaics to quantum information science. One of the most significant barriers limiting such dimers is the fast recombination of the triplet pair, which prevents spatial separation and the formation of long-lived triplet states. There is an ever-growing need to develop general synthetic strategies to control the evolution of triplets following iSF and enhance their lifetime. Here, we rationally tune the dihedral angle and interchromophore separation between pairs of pentacenes in a systematic series of bridging units to facilitate triplet separation. Through a combination of transient optical and spin-resonance techniques, we demonstrate that torsion within the linker provides a simple synthetic handle to tune the fine balance between through-bond and through-space interchromophore couplings that steer iSF. We show that the full iSF pathway from femtosecond to microsecond timescales is tuned through the static coupling set by molecular design and structural fluctuations that can be biased through steric control. Our approach highlights a straightforward design principle to generate paramagnetic spin pair states with higher yields.
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Affiliation(s)
- Kanad Majumder
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - Soham Mukherjee
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Naitik A Panjwani
- Berlin Joint EPR Lab, Fachbereich Physik, Freie Universität, Berlin, Berlin 14195, Berlin, Germany
| | - Jieun Lee
- Department of Chemistry, Yonsei University, Seoul 03722, Republic of Korea
| | - Robert Bittl
- Berlin Joint EPR Lab, Fachbereich Physik, Freie Universität, Berlin, Berlin 14195, Berlin, Germany
| | - Woojae Kim
- Department of Chemistry, Yonsei University, Seoul 03722, Republic of Korea
| | - Satish Patil
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - Andrew J Musser
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
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8
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Jung S, Wang L, Sugiyama H, Uekusa H, Katayama T, Kamada K, Hamura T, Tamai N. Intramolecular Singlet Fission in Pentacene Oligomers via an Intermediate State. J Phys Chem B 2023; 127:4554-4561. [PMID: 37191388 DOI: 10.1021/acs.jpcb.3c00516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Intramolecular singlet fission (iSF) is an efficient strategy of multiexciton generation via a singlet exciton splitting into a correlated triplet pair in one organic molecule with more than two chromophores. Propeller-shaped iptycene-linked triisopropylsilyl(TIPS)-ethynyl functionalized pentacene oligomers (pent-monomer, pent-dimer, and pent-trimer) were synthesized, and the iSF dynamics of pent-dimer and -trimer were monitored by a visible-near-IR transient absorption (TA) spectroscopy. Quantum yields of the triplet pair, ∼80%, of both estimated by near-IR TA spectral analysis are in good agreement with the results of global analysis and triplet sensitization experiments. The iSF rate of pent-trimer is slightly faster than that of pent-dimer even with one more chromophore site. The unexpectedly weak difference indicates the existence of an intermediate process to realize iSF. The intermediate process might be determined by through-bond electronic coupling of the homoconjugation bridge in the pentacene oligomers. Our results suggest the importance of the rigid bridge to the fast iSF rate and the elongated lifetime of the correlated triplet pair in pentacene oligomers.
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Affiliation(s)
- Sunna Jung
- Department of Applied Chemistry for Environment, Graduate School of Science and Technology, Kwansei Gakuin University, 669-1330 Sanda, Japan
| | - Li Wang
- Department of Chemistry, Graduate School of Science and Technology, Kwansei Gakuin University, 669-1330 Sanda, Japan
| | - Haruki Sugiyama
- Department of Chemistry, Tokyo Institute of Technology, 2-12-1 Ookayama, Megro-ku, 152-8551 Tokyo, Japan
| | - Hidehiro Uekusa
- Department of Chemistry, Tokyo Institute of Technology, 2-12-1 Ookayama, Megro-ku, 152-8551 Tokyo, Japan
| | - Tetsuro Katayama
- Department of Chemistry, Graduate School of Science and Technology, Kwansei Gakuin University, 669-1330 Sanda, Japan
| | - Kenji Kamada
- IFMRI, National Institute of Advanced Industrial Science and Technology (AIST), 563-8577 Osaka, Japan
| | - Toshiyuki Hamura
- Department of Applied Chemistry for Environment, Graduate School of Science and Technology, Kwansei Gakuin University, 669-1330 Sanda, Japan
| | - Naoto Tamai
- Department of Chemistry, Graduate School of Science and Technology, Kwansei Gakuin University, 669-1330 Sanda, Japan
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9
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Pradhan E, Zeng T. Triplet Separation after the Fastest Intramolecular Singlet Fission in the Smallest Chromophore. J Chem Theory Comput 2023; 19:2092-2101. [PMID: 36966419 DOI: 10.1021/acs.jctc.3c00096] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/27/2023]
Abstract
Singlet fission is of key importance in harvesting solar energy in solar cells, as it generates a pair of triplet excitons on the incidence of a photon. This phenomenon is not yet widely employed in the organic photovoltaics industry mostly because of the rarity of singlet fission chromophores. Pyrazino[2,3-g]quinoxaline-1,4,6,9-tetraoxide was recently designed as the smallest intramolecular singlet fission chromophore, and it undergoes the fastest singlet fission with a 16 fs time scale. The subsequent separation of the generated triplet-pair is of likewise importance as their efficient generation. Through quantum chemistry calculations and quantum dynamics simulations, we show that the triplet-pair separates to residing on two chromophores with an ∼80% probability on each collision between a chromophore with the triplet-pair and a ground state chromophore. Avoided crossing, instead of conical intersection, is involved in the efficient exciton separation.
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Affiliation(s)
- Ekadashi Pradhan
- Department of Chemistry, York University, Toronto, Ontario M3J1P3, Canada
| | - Tao Zeng
- Department of Chemistry, York University, Toronto, Ontario M3J1P3, Canada
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10
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Pradhan E, Zeng T. Design of the Smallest Intramolecular Singlet Fission Chromophore with the Fastest Singlet Fission. J Phys Chem Lett 2022; 13:11076-11085. [PMID: 36417555 DOI: 10.1021/acs.jpclett.2c03131] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
We designed an intramolecular singlet fission (iSF) chromophore, pyrazino[2,3-g]quinoxaline-1,4,6,9-tetraoxide. Appropriate substitutions into anthracene enhance the tetraradical character, so that the molecule accommodates a pair of triplet excitons in its lowest singlet excited state. Our simulation showed a 16 fs fast iSF of the design, which is a new record. The design also sets a new record of small size iSF chromophore and high exciton density. The design can be synthesized by oxidizing the tertiary N centers of the existent pyrazino[2,3-g]quinoxaline.
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Affiliation(s)
- Ekadashi Pradhan
- Department of Chemistry, York University, Toronto, Ontario M3J1P3, Canada
| | - Tao Zeng
- Department of Chemistry, York University, Toronto, Ontario M3J1P3, Canada
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11
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Ringström R, Edhborg F, Schroeder ZW, Chen L, Ferguson MJ, Tykwinski RR, Albinsson B. Molecular rotational conformation controls the rate of singlet fission and triplet decay in pentacene dimers. Chem Sci 2022; 13:4944-4954. [PMID: 35655894 PMCID: PMC9067590 DOI: 10.1039/d1sc06285a] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 04/03/2022] [Indexed: 12/02/2022] Open
Abstract
Three pentacene dimers have been synthesized to investigate the effect of molecular rotation and rotational conformations on singlet fission (SF). In all three dimers, the pentacene units are linked by a 1,4-diethynylphenylene spacer that provides almost unimpeded rotational freedom between the pentacene- and phenylene-subunits in the parent dimer. Substituents on the phenylene spacer add varying degrees of steric hindrance that restricts both the rotation and the equilibrium distribution of different conformers; the less restricted conformers exhibit faster SF and more rapid subsequent triplet-pair recombination. Furthermore, the rotational conformers have small shifts in their absorption spectra and this feature has been used to selectively excite different conformers and study the resulting SF. Femtosecond transient absorption studies at 100 K reveal that the same dimer can have orders of magnitude faster SF in a strongly coupled conformer compared to a more weakly coupled one. Measurements in polystyrene further show that the SF rate is nearly independent of viscosity whereas the triplet pair lifetime is considerably longer in a high viscosity medium. The results provide insight into design criteria for maintaining high initial SF rate while suppressing triplet recombination in intramolecular singlet fission.
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Affiliation(s)
- Rasmus Ringström
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology Kemigården 4 SE-412 96 Göteborg Sweden
| | - Fredrik Edhborg
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology Kemigården 4 SE-412 96 Göteborg Sweden
| | - Zachary W Schroeder
- Department of Chemistry, University of Alberta Edmonton Alberta T6G 2G2 Canada
| | - Lan Chen
- Department of Chemistry, University of Alberta Edmonton Alberta T6G 2G2 Canada
| | - Michael J Ferguson
- Department of Chemistry, University of Alberta Edmonton Alberta T6G 2G2 Canada
| | - Rik R Tykwinski
- Department of Chemistry, University of Alberta Edmonton Alberta T6G 2G2 Canada
| | - Bo Albinsson
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology Kemigården 4 SE-412 96 Göteborg Sweden
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12
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Mohamed Abdelmoniem A, Abdelshafy Abdelhamid I, Butenschön H. Bidirectional Synthesis, Photophysical and Electrochemical Characterization of Polycyclic Quinones Using Benzocyclobutenes and Benzodicyclobutenes as Precursors. European J Org Chem 2021. [DOI: 10.1002/ejoc.202100848] [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)
- Amr Mohamed Abdelmoniem
- Institut für Organische Chemie Leibniz Universität Hannover Schneiderberg 1B 30167 Hannover Germany
- Department of Chemistry Faculty of Science Cairo University 12613 Giza A. R. Egypt
| | | | - Holger Butenschön
- Institut für Organische Chemie Leibniz Universität Hannover Schneiderberg 1B 30167 Hannover Germany
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13
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Hoche J, Flock M, Miao X, Philipp LN, Wenzel M, Fischer I, Mitric R. Excimer formation dynamics in the isolated tetracene dimer. Chem Sci 2021; 12:11965-11975. [PMID: 34667562 PMCID: PMC8457379 DOI: 10.1039/d1sc03214c] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Accepted: 08/01/2021] [Indexed: 12/20/2022] Open
Abstract
The understanding of excimer formation and its interplay with the singlet-correlated triplet pair state 1(TT) is of high significance for the development of efficient organic electronics. Here, we study the photoinduced dynamics of the tetracene dimer in the gas phase by time-resolved photoionisation and photoion imaging experiments as well as nonadiabatic dynamics simulations in order to obtain mechanistic insight into the excimer formation dynamics. The experiments are performed using a picosecond laser system for excitation into the S2 state and reveal a biexponential time dependence. The time constants, obtained as a function of excess energy, lie in the range between ≈10 ps and 100 ps and are assigned to the relaxation of the excimer on the S1 surface and to its deactivation to the ground state. Simulations of the quantum-classical photodynamics are carried out in the frame of the semi-empirical CISD and TD-lc-DFTB methods. Both theoretical approaches reveal a dominating relaxation pathway that is characterised by the formation of a perfectly stacked excimer. TD-lc-DFTB simulations have also uncovered a second relaxation channel into a less stable dimer conformation in the S1 state. Both methods have consistently shown that the electronic and geometric relaxation to the excimer state is completed in less than 10 ps. The inclusion of doubly excited states in the CISD dynamics and their diabatisation further allowed to observe a transient population of the 1(TT) state, which, however, gets depopulated on a timescale of 8 ps, leading finally to the trapping in the excimer minimum. The understanding of excimer formation and its interplay with the singlet-correlated triplet pair state 1(TT) is of high significance for the development of efficient organic electronics.![]()
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Affiliation(s)
- Joscha Hoche
- Institut für Physikalische und Theoretische Chemie, Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Marco Flock
- Institut für Physikalische und Theoretische Chemie, Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Xincheng Miao
- Institut für Physikalische und Theoretische Chemie, Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Luca Nils Philipp
- Institut für Physikalische und Theoretische Chemie, Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Michael Wenzel
- Institut für Physikalische und Theoretische Chemie, Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Ingo Fischer
- Institut für Physikalische und Theoretische Chemie, Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Roland Mitric
- Institut für Physikalische und Theoretische Chemie, Universität Würzburg Am Hubland 97074 Würzburg Germany
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14
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Shizu K, Adachi C, Kaji H. Correlated Triplet Pair Formation Activated by Geometry Relaxation in Directly Linked Tetracene Dimer (5,5'-Bitetracene). ACS OMEGA 2021; 6:2638-2643. [PMID: 33553881 PMCID: PMC7859935 DOI: 10.1021/acsomega.0c04809] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 11/17/2020] [Indexed: 06/12/2023]
Abstract
Singlet fission (SF) materials have the potential to overcome the traditional external quantum efficiency limits of organic light-emitting diodes (OLEDs). In this study, we theoretically designed an intramolecular SF molecule, 5,5'-bitetracene (55BT), in which two tetracene units were directly connected through a C-C bond. Using quantum chemical calculation and the Fermi golden rule, we show that 55BT undergoes efficient SF induced by geometry relaxation in a locally excited singlet state, 1(S0S1). Compared with another high-performing SF system, the tetracene dimer in the crystalline state, 55BT has advantages when used in doped systems owing to covalent bonding of the two tetracene units. This feature makes 55BT a promising candidate triplet sensitizer for near-infrared OLEDs.
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Affiliation(s)
- Katsuyuki Shizu
- Institute
for Chemical Research, Kyoto University, Uji, Kyoto]611-0011, Japan
| | - Chihaya Adachi
- Center
for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395, Japan
- International
Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395, Japan
- Japan
Science and Technology Agency (JST), ERATO, Adachi Molecular Exciton
Engineering Project, 744 Motooka, Nishi, Fukuoka 819-0395, Japan
| | - Hironori Kaji
- Institute
for Chemical Research, Kyoto University, Uji, Kyoto]611-0011, Japan
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15
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Walwark DJ, Grey JK. Dynamic emissive signatures of intramolecular singlet fission during equilibration to steady state revealed from stochastic kinetic simulations. J Chem Phys 2020; 153:234102. [PMID: 33353319 DOI: 10.1063/5.0027579] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We investigate the ability of dynamic fluorescence probes to accurately track populations of multi-excitonic states in molecular dyads based on conjugated acenes capable of intramolecular singlet fission (iSF). Stochastic simulations of reported photophysical models from time-resolved spectroscopic studies of iSF dyads based on large acenes (e.g., tetracene and pentacene) are used to extrapolate population and fluorescence yield dynamics. The approach entails the use of repetitive rectangular-shaped excitation waveforms as a stimulus, with durations comparable to triplet lifetimes. We observe unique dynamics signatures that can be directly related to relaxation of multi-exciton states involved over the entire effective time of singlet fission in the presence and absence of an excitation light stimulus. In particular, time-dependent fluorescence yields display an abrupt decay followed by slower rise dynamics appearing as a prominent "dip" feature in responses. The initial fast decrease in the fluorescence yield arises from the formation of triplet pairs and separated triplets that do not produce emission resembling a complete ground state bleach effect. However, relaxation of one separated triplet allows the system to absorb, and in some cases, this increases the fluorescence yield, causing rise dynamics in the emissive response. Our approach also permits extrapolation of all multi-exciton state population dynamics up to steady state conditions in addition to the ability to explore consequences of alternative relaxation channels. The results demonstrate that it is possible to resolve unique signatures of singlet fission events from dynamic fluorescence studies, which can augment detection capabilities and extend sensitivity limits and accessible time scales.
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Affiliation(s)
- David J Walwark
- Department of Chemistry, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - John K Grey
- Department of Chemistry, University of New Mexico, Albuquerque, New Mexico 87131, USA
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16
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Cruz CD, Chronister EL, Bardeen CJ. Using temperature dependent fluorescence to evaluate singlet fission pathways in tetracene single crystals. J Chem Phys 2020; 153:234504. [PMID: 33353314 DOI: 10.1063/5.0031458] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The temperature-dependent fluorescence spectrum, decay rate, and spin quantum beats are examined in single tetracene crystals to gain insight into the mechanism of singlet fission. Over the temperature range of 250 K-500 K, the vibronic lineshape of the emission indicates that the singlet exciton becomes localized at 400 K. The fission process is insensitive to this localization and exhibits Arrhenius behavior with an activation energy of 550 ± 50 cm-1. The damping rate of the triplet pair spin quantum beats in the delayed fluorescence also exhibits an Arrhenius temperature dependence with an activation energy of 165 ± 70 cm-1. All the data for T > 250 K are consistent with direct production of a spatially separated 1(T⋯T) state via a thermally activated process, analogous to spontaneous parametric downconversion of photons. For temperatures in the range of 20 K-250 K, the singlet exciton continues to undergo a rapid decay on the order of 200 ps, leaving a red-shifted emission that decays on the order of 100 ns. At very long times (≈1 µs), a delayed fluorescence component corresponding to the original S1 state can still be resolved, unlike in polycrystalline films. A kinetic analysis shows that the redshifted emission seen at lower temperatures cannot be an intermediate in the triplet production. When considered in the context of other results, our data suggest that the production of triplets in tetracene for temperatures below 250 K is a complex process that is sensitive to the presence of structural defects.
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Affiliation(s)
- Chad D Cruz
- Department of Chemistry, University of California Riverside, Riverside, California 92521, USA
| | - Eric L Chronister
- Department of Chemistry and Biochemistry, University of Nevada, Las Vegas, 4505 S. Maryland Parkway, Las Vegas, Nevada 89154, USA
| | - Christopher J Bardeen
- Department of Chemistry, University of California Riverside, Riverside, California 92521, USA
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17
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Alagna N, Lustres JLP, Roozbeh A, Han J, Hahn S, Berger FJ, Zaumseil J, Dreuw A, Bunz UHF, Buckup T. Ultrafast Singlet Fission in Rigid Azaarene Dimers with Negligible Orbital Overlap. J Phys Chem B 2020; 124:9163-9174. [DOI: 10.1021/acs.jpcb.0c07096] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Nicolò Alagna
- Physikalisch Chemisches Institut, Universität Heidelberg, D-69120 Heidelberg, Germany
- Centre for Advanced Materials, Universität Heidelberg, D-69120 Heidelberg, Germany
| | - Jose Luis Pérez Lustres
- Physikalisch Chemisches Institut, Universität Heidelberg, D-69120 Heidelberg, Germany
- Centre for Advanced Materials, Universität Heidelberg, D-69120 Heidelberg, Germany
| | - Ashkan Roozbeh
- Physikalisch Chemisches Institut, Universität Heidelberg, D-69120 Heidelberg, Germany
- Centre for Advanced Materials, Universität Heidelberg, D-69120 Heidelberg, Germany
| | - Jie Han
- Interdisziplinäres Zentrum für Wissenschaftliches Rechnen, Universität Heidelberg, D-69120 Heidelberg, Germany
- Centre for Advanced Materials, Universität Heidelberg, D-69120 Heidelberg, Germany
| | - Sebastian Hahn
- Organisch Chemisches Institut, Universität Heidelberg, D-69120 Heidelberg, Germany
| | - Felix J. Berger
- Physikalisch Chemisches Institut, Universität Heidelberg, D-69120 Heidelberg, Germany
- Centre for Advanced Materials, Universität Heidelberg, D-69120 Heidelberg, Germany
| | - Jana Zaumseil
- Physikalisch Chemisches Institut, Universität Heidelberg, D-69120 Heidelberg, Germany
- Centre for Advanced Materials, Universität Heidelberg, D-69120 Heidelberg, Germany
| | - Andreas Dreuw
- Interdisziplinäres Zentrum für Wissenschaftliches Rechnen, Universität Heidelberg, D-69120 Heidelberg, Germany
- Centre for Advanced Materials, Universität Heidelberg, D-69120 Heidelberg, Germany
| | - Uwe H. F. Bunz
- Organisch Chemisches Institut, Universität Heidelberg, D-69120 Heidelberg, Germany
- Centre for Advanced Materials, Universität Heidelberg, D-69120 Heidelberg, Germany
| | - Tiago Buckup
- Physikalisch Chemisches Institut, Universität Heidelberg, D-69120 Heidelberg, Germany
- Centre for Advanced Materials, Universität Heidelberg, D-69120 Heidelberg, Germany
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18
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Hong Y, Kim J, Kim W, Kaufmann C, Kim H, Würthner F, Kim D. Efficient Multiexciton State Generation in Charge-Transfer-Coupled Perylene Bisimide Dimers via Structural Control. J Am Chem Soc 2020; 142:7845-7857. [DOI: 10.1021/jacs.0c00870] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Yongseok Hong
- Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul 03722, Korea
| | - Juno Kim
- Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul 03722, Korea
| | - Woojae Kim
- Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul 03722, Korea
| | - Christina Kaufmann
- Universitat Würzburg, Institut für Organische Chemie & Center for Nanosystems Chemistry, Am Hubland, Würzburg 97074, Germany
| | - Hyungjun Kim
- Department of Chemistry, Incheon National University, 119 Academy-ro, Yeonsu-gu, Incheon 22012, Korea
- Research Institute of Basic Sciences, Incheon National University, 119 Academy-ro, Yeonsu-gu, Incheon 22012, Korea
| | - Frank Würthner
- Universitat Würzburg, Institut für Organische Chemie & Center for Nanosystems Chemistry, Am Hubland, Würzburg 97074, Germany
| | - Dongho Kim
- Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul 03722, Korea
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19
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Spatial separation of triplet excitons drives endothermic singlet fission. Nat Chem 2020; 12:391-398. [PMID: 32123340 DOI: 10.1038/s41557-020-0422-7] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 01/14/2020] [Indexed: 11/08/2022]
Abstract
Molecules that undergo singlet fission, converting singlet excitons into pairs of triplet excitons, have potential as photovoltaic materials. The possible advantages of endothermic singlet fission (enhanced use of photon energy and larger triplet energies for coupling with common absorbers) motivated us to assess the role of exciton delocalization in the activation of this process. Here we report the synthesis of a series of linear perylene oligomers that undergo endothermic singlet fission and have endothermicities in the range 5-10 kBT at room temperature in solution. We study these compounds using transient spectroscopy and modelling to unravel the singlet and triplet dynamics. We show that the minimal number of coupled chromophores needed to undergo endothermic singlet fission is three, which provides sufficient statistical space for triplet excitons to separate and avoid annihilation-and a subsequent fast return to the singlet state. Our data additionally suggest that torsional motion of chromophores about the molecular axis following triplet-pair separation contributes to the increase in entropy, thus lengthening the triplet lifetime in longer oligomers.
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20
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Korovina NV, Pompetti NF, Johnson JC. Lessons from intramolecular singlet fission with covalently bound chromophores. J Chem Phys 2020; 152:040904. [PMID: 32007061 DOI: 10.1063/1.5135307] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Molecular dimers, oligomers, and polymers are versatile components in photophysical and optoelectronic architectures that could impact a variety of applications. We present a perspective on such systems in the field of singlet fission, which effectively multiplies excitons and produces a unique excited state species, the triplet pair. The choice of chromophore and the nature of the attachment between units, both geometrical and chemical, play a defining role in the dynamical scheme that evolves upon photoexcitation. Specific final outcomes (e.g., separated and uncorrelated triplet pairs) are being sought through rational design of covalently bound chromophore architectures built with guidance from recent fundamental studies that correlate structure with excited state population flow kinetics.
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Affiliation(s)
- Nadezhda V Korovina
- National Renewable Energy Laboratory, 15013 Denver West Pkwy, Golden, Colorado 80401, USA
| | - Nicholas F Pompetti
- National Renewable Energy Laboratory, 15013 Denver West Pkwy, Golden, Colorado 80401, USA
| | - Justin C Johnson
- National Renewable Energy Laboratory, 15013 Denver West Pkwy, Golden, Colorado 80401, USA
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21
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Imperiale CJ, Green PB, Miller EG, Damrauer NH, Wilson MWB. Triplet-Fusion Upconversion Using a Rigid Tetracene Homodimer. J Phys Chem Lett 2019; 10:7463-7469. [PMID: 31751145 DOI: 10.1021/acs.jpclett.9b03115] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We demonstrate that a structurally rigid, weakly coupled molecular dimer can replace traditional monomeric annihilators for triplet fusion upconversion (TUC) in solution by observing emitted photons (λ = 540 nm) from a norbornyl-bridged tetracene homodimer following excitation of a triplet sensitizer at λ = 730 nm. Intriguingly, steady-state spectroscopy, kinetic simulations, and Stern-Volmer quenching experiments show that the dimer exhibits qualitatively different photophysics than its parent monomer: it is less effective at diffusion-mediated triplet exciton transfer, but it fuses extracted triplets more efficiently. Our results support the development of composite triplet-fusion platforms that go beyond diffusion-mediated triplet extraction, ultimately circumventing the concentration dependence of solution-phase TUC.
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Affiliation(s)
| | - Philippe B Green
- Department of Chemistry , University of Toronto , Toronto , Ontario M5S3H6 , Canada
| | - Ethan G Miller
- Department of Chemistry and Biochemistry , University of Colorado, Boulder , Boulder , Colorado 80302 , United States
| | - Niels H Damrauer
- Department of Chemistry and Biochemistry , University of Colorado, Boulder , Boulder , Colorado 80302 , United States
| | - Mark W B Wilson
- Department of Chemistry , University of Toronto , Toronto , Ontario M5S3H6 , Canada
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22
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Collins MI, McCamey DR, Tayebjee MJY. Fluctuating exchange interactions enable quintet multiexciton formation in singlet fission. J Chem Phys 2019; 151:164104. [PMID: 31675884 DOI: 10.1063/1.5115816] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Several recent electron spin resonance studies have observed a quintet multiexciton state during the singlet fission process. Here, we provide a general theoretical explanation for the generation of this state by invoking a time-varying exchange coupling between pairs of triplet excitons and subsequently solving the relevant time-varying spin Hamiltonian for different rates at which the exchange coupling varies. We simulate experimental ESR spectra and draw qualitative conclusions about the adiabatic and diabatic transitions between triplet pair spin states.
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Affiliation(s)
- Miles I Collins
- ARC Centre of Excellence in Exciton Science, School of Physics, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Dane R McCamey
- ARC Centre of Excellence in Exciton Science, School of Physics, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Murad J Y Tayebjee
- School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney, New South Wales 2052, Australia
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23
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Wang Z, Zhang C, Wang R, Wang G, Wang X, Xiao M. Weakly coupled triplet pair states probed by quantum beating in delayed fluorescence in tetracene crystals. J Chem Phys 2019; 151:134309. [DOI: 10.1063/1.5110188] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Zhiwei Wang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Chunfeng Zhang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Rui Wang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Guodong Wang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Xiaoyong Wang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Min Xiao
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701, USA
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24
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Sun D, Deng GH, Xu B, Xu E, Li X, Wu Y, Qian Y, Zhong Y, Nuckolls C, Harutyunyan AR, Dai HL, Chen G, Chen H, Rao Y. Anisotropic Singlet Fission in Single Crystalline Hexacene. iScience 2019; 19:1079-1089. [PMID: 31522118 PMCID: PMC6745488 DOI: 10.1016/j.isci.2019.08.053] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 07/01/2019] [Accepted: 08/26/2019] [Indexed: 11/25/2022] Open
Abstract
Singlet fission is known to improve solar energy utilization by circumventing the Shockley-Queisser limit. The two essential steps of singlet fission are the formation of a correlated triplet pair and its subsequent quantum decoherence. However, the mechanisms of the triplet pair formation and decoherence still remain elusive. Here we examined both essential steps in single crystalline hexacene and discovered remarkable anisotropy of the overall singlet fission rate along different crystal axes. Since the triplet pair formation emerges on the same timescale along both crystal axes, the quantum decoherence is likely responsible for the directional anisotropy. The distinct quantum decoherence rates are ascribed to the notable difference on their associated energy loss according to the Redfield quantum dissipation theory. Our hybrid experimental/theoretical framework will not only further our understanding of singlet fission, but also shed light on the systematic design of new materials for the third-generation solar cells.
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Affiliation(s)
- Dezheng Sun
- Department of Physics, Columbia University, New York, NY 10027, USA
| | - Gang-Hua Deng
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322, USA
| | - Bolei Xu
- Department of Chemistry, Temple University, Philadelphia, PA 19122, USA
| | - Enshi Xu
- Department of Chemistry, George Washington University, Washington, DC 20052, USA
| | - Xia Li
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322, USA
| | - Yajing Wu
- Department of Chemistry, Temple University, Philadelphia, PA 19122, USA
| | - Yuqin Qian
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322, USA
| | - Yu Zhong
- Department of Chemistry, Columbia University, New York, NY 10027, USA
| | - Colin Nuckolls
- Department of Chemistry, Columbia University, New York, NY 10027, USA
| | | | - Hai-Lung Dai
- Department of Chemistry, Temple University, Philadelphia, PA 19122, USA
| | - Gugang Chen
- Honda Research Institute USA, Inc., San Jose, CA 95134, USA.
| | - Hanning Chen
- Department of Chemistry, George Washington University, Washington, DC 20052, USA.
| | - Yi Rao
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322, USA.
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25
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Sanders SN, Pun AB, Parenti KR, Kumarasamy E, Yablon LM, Sfeir MY, Campos LM. Understanding the Bound Triplet-Pair State in Singlet Fission. Chem 2019. [DOI: 10.1016/j.chempr.2019.05.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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26
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Japahuge A, Lee S, Choi CH, Zeng T. Design of singlet fission chromophores with cyclic (alkyl)(amino) carbene building blocks. J Chem Phys 2019; 150:234306. [PMID: 31228896 DOI: 10.1063/1.5099062] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
We use MRSF-TDDFT and NEVPT2 methods to design singlet fission chromophores with the building blocks of cyclic (alkyl)(amino)carbenes (CAACs). CAAC dimers with C2, C4, and p-phenylene spacers are considered. The substitutions with trifluoromethyls and fluorine atoms at the α C position are investigated. The electronegative substituents enhance the π accepting capability of the α C while maintaining it as a quaternary C atom. The phenylene-connected dimers with the two substitutions are identified as promising candidates for singlet fission chromophores. The cylindrically symmetric C2 and C4 spacers allow for substantial structural reorganizations in the S0-to-S1 and S0-to-T1 excitations. Although the two substituted dimers with the C4 spacer satisfy (or very close to satisfy) the primary thermodynamics criterion for singlet fission, the significant structural reorganizations result in high barriers so that the fission is kinetically unfavorable.
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Affiliation(s)
- Achini Japahuge
- Department of Chemistry, Carleton University, Ottawa, Ontario K1S5B6, Canada
| | - Seunghoon Lee
- Department of Chemistry, Seoul National University, Seoul 151-747, South Korea
| | - Cheol Ho Choi
- Department of Chemistry, Kyungpook National University, Daegu 702-701, South Korea
| | - Tao Zeng
- Department of Chemistry, Carleton University, Ottawa, Ontario K1S5B6, Canada
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27
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Buchanan EA, Kaleta J, Wen J, Lapidus SH, Císařová I, Havlas Z, Johnson JC, Michl J. Molecular Packing and Singlet Fission: The Parent and Three Fluorinated 1,3-Diphenylisobenzofurans. J Phys Chem Lett 2019; 10:1947-1953. [PMID: 30883125 DOI: 10.1021/acs.jpclett.8b03875] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Crystal structures, singlet fission (SF) rate constants, and other photophysical properties are reported for three fluorinated derivatives of 1,3-diphenylisobenzofuran and compared with those of the two crystal forms of the parent. The results place constraints on the notion that the effects of molecular packing on SF rates could be studied separately from effects of chromophore structural changes by examining groups of chromophores related by weakly perturbing substitution if their crystal structures are different. The results further provide experimental evidence that dimer-based models of SF are not sufficiently general and that trimer- and possibly even higher oligomer-based or many-body models need to be formulated.
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Affiliation(s)
- Eric A Buchanan
- Department of Chemistry , University of Colorado , Boulder , Colorado 80309 , United States
| | - Jiří Kaleta
- Department of Chemistry , University of Colorado , Boulder , Colorado 80309 , United States
- Institute of Organic Chemistry and Biochemistry , Academy of Sciences of the Czech Republic , Flemingovo nám. 2 , 16610 Prague 6 , Czech Republic
| | - Jin Wen
- Institute of Organic Chemistry and Biochemistry , Academy of Sciences of the Czech Republic , Flemingovo nám. 2 , 16610 Prague 6 , Czech Republic
| | - Saul H Lapidus
- Advanced Photon Source , Argonne National Laboratory , 9700 South Cass Avenue, Building 433/D002 , Argonne , Illinois 60439 , United States
| | - Ivana Císařová
- Department of Inorganic Chemistry, Faculty of Science , Charles University , Hlavova 2030 , 12840 Prague , Czech Republic
| | - Zdeněk Havlas
- Institute of Organic Chemistry and Biochemistry , Academy of Sciences of the Czech Republic , Flemingovo nám. 2 , 16610 Prague 6 , Czech Republic
| | - Justin C Johnson
- National Renewable Energy Laboratory , Golden , Colorado 80401 , United States
| | - Josef Michl
- Department of Chemistry , University of Colorado , Boulder , Colorado 80309 , United States
- Institute of Organic Chemistry and Biochemistry , Academy of Sciences of the Czech Republic , Flemingovo nám. 2 , 16610 Prague 6 , Czech Republic
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28
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Basel BS, Hetzer C, Zirzlmeier J, Thiel D, Guldi R, Hampel F, Kahnt A, Clark T, Guldi DM, Tykwinski RR. Davydov splitting and singlet fission in excitonically coupled pentacene dimers. Chem Sci 2019; 10:3854-3863. [PMID: 31015927 PMCID: PMC6461118 DOI: 10.1039/c9sc00384c] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 02/21/2019] [Indexed: 11/21/2022] Open
Abstract
Singlet fission (SF) allows two charges to be generated from the absorption of a single photon and is, therefore, potentially transformative toward improving solar energy conversion. Key to the present study of SF is the design of pentacene dimers featuring a xanthene linker that strictly places two pentacene chromophores in a rigid arrangement and, in turn, enforces efficient, intramolecular π-overlap that mimics interactions typically found in condensed state (e.g., solids, films, etc.). Inter-chromophore communication ensures Davydov splitting, which plays an unprecedented role toward achieving SF in pentacene dimers. Transient absorption measurements document that intramolecular SF evolves upon excitation into the lower Davydov bands to form a correlated triplet pair at cryogenic temperature. At room temperature, the two spin-correlated triplets, one per pentacene moiety within the dimers, are electronically coupled to an excimer state. The presented results are transferable to a broad range of acene morphologies including aggregates, crystals, and films.
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Affiliation(s)
- Bettina Sabine Basel
- Department of Chemistry and Pharmacy , Interdisciplinary Center for Molecular Materials (ICMM) , Friedrich-Alexander-Universität (FAU) , Egerlandstrasse 3 , 91058 Erlangen , Germany .
| | - Constantin Hetzer
- Department of Chemistry and Pharmacy , Interdisciplinary Center for Molecular Materials (ICMM) , Friedrich-Alexander-Universität (FAU) , Nikolaus-Fiebiger-Strasse 10 , 91058 Erlangen , Germany
| | - Johannes Zirzlmeier
- Department of Chemistry and Pharmacy , Interdisciplinary Center for Molecular Materials (ICMM) , Friedrich-Alexander-Universität (FAU) , Egerlandstrasse 3 , 91058 Erlangen , Germany .
| | - Dominik Thiel
- Department of Chemistry and Pharmacy , Interdisciplinary Center for Molecular Materials (ICMM) , Friedrich-Alexander-Universität (FAU) , Egerlandstrasse 3 , 91058 Erlangen , Germany .
| | - Rebecca Guldi
- Department of Chemistry and Pharmacy , Interdisciplinary Center for Molecular Materials (ICMM) , Friedrich-Alexander-Universität (FAU) , Nikolaus-Fiebiger-Strasse 10 , 91058 Erlangen , Germany
| | - Frank Hampel
- Department of Chemistry and Pharmacy , Interdisciplinary Center for Molecular Materials (ICMM) , Friedrich-Alexander-Universität (FAU) , Nikolaus-Fiebiger-Strasse 10 , 91058 Erlangen , Germany
| | - Axel Kahnt
- Leibniz Institute of Surface Engineering (IOM) , Permoserstr. 15 , D-04318 Leipzig , Germany
| | - Timothy Clark
- Department of Chemistry and Pharmacy , Computer-Chemistry-Center (CCC) , Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) , Nägelsbachstrasse 25 , 91052 Erlangen , Germany .
| | - Dirk Michael Guldi
- Department of Chemistry and Pharmacy , Interdisciplinary Center for Molecular Materials (ICMM) , Friedrich-Alexander-Universität (FAU) , Egerlandstrasse 3 , 91058 Erlangen , Germany .
| | - Rik R Tykwinski
- Department of Chemistry , University of Alberta , Edmonton , Alberta, T6G 2G2 , Canada .
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29
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Gilligan AT, Miller EG, Sammakia T, Damrauer NH. Using Structurally Well-Defined Norbornyl-Bridged Acene Dimers to Map a Mechanistic Landscape for Correlated Triplet Formation in Singlet Fission. J Am Chem Soc 2019; 141:5961-5971. [PMID: 30888804 DOI: 10.1021/jacs.9b00904] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Structurally well-defined TIPS-acetylene substituted tetracene (TIPS-BT1') and pentacene (TIPS-BP1') dimers utilizing a [2.2.1] bicyclic norbornyl bridge have been studied-primarily using time-resolved spectroscopic methods-to uncover mechanistic details about primary steps in singlet fission leading to formation of the biexcitonic 1TT state as well as decay pathways to the ground state. For TIPS-BP1' in room-temperature toluene, 1TT formation is rapid and complete, occurring in 4.4 ps. Decay to the ground state in 100 ns is the primary loss pathway for 1TT in this system. For TIPS-BT1', the 1TT is also observed to form rapidly (with a time constant of 5 ps), but in this case it occurs in concert with establishment of an excited-state equilibrium ( K ∼ 1) with the singlet exciton state S1 at an energy of 2.3 eV above the ground state. The equilibrated states survive for 36 ns and are lost to ground state through both radiative and nonradiative pathways via the S1 and nonradiative pathways via the 1TT. The rapidity of 1TT formation in TIPS-BT1' is at first glance surprising. However, our analysis suggests that the few-parameter rate constant expression of Marcus theory explains both individual and comparative findings in the set of systems, thus establishing benchmarks for diabatic coupling and reorganization energy needed for efficient 1TT formation. Finally, a comparison of TIPS-BT1' with previous results obtained for a close constitutional isomer (TIPS-BT1) differing in the placement of TIPS-acetylene side groups suggests that the magnitude of exchange interaction in the correlated triplet manifold plays a critical role dictating 1TT yield in the tetracenic systems.
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Affiliation(s)
- Alexander T Gilligan
- Department of Chemistry and Biochemistry , University of Colorado Boulder , Boulder , Colorado 80309 , United States
| | - Ethan G Miller
- Department of Chemistry and Biochemistry , University of Colorado Boulder , Boulder , Colorado 80309 , United States
| | - Tarek Sammakia
- Department of Chemistry and Biochemistry , University of Colorado Boulder , Boulder , Colorado 80309 , United States
| | - Niels H Damrauer
- Department of Chemistry and Biochemistry , University of Colorado Boulder , Boulder , Colorado 80309 , United States
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30
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Hele TJH, Fuemmeler EG, Sanders SN, Kumarasamy E, Sfeir MY, Campos LM, Ananth N. Anticipating Acene-Based Chromophore Spectra with Molecular Orbital Arguments. J Phys Chem A 2019; 123:2527-2536. [PMID: 30802051 DOI: 10.1021/acs.jpca.8b12222] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Recent synthetic studies on the organic molecules tetracene and pentacene have found certain dimers and oligomers to exhibit an intense absorption in the visible region of the spectrum that is not present in the monomer or many previously studied dimers. In this article we combine experimental synthesis with electronic structure theory and spectral computation to show that this absorption arises from an otherwise dark charge-transfer excitation "borrowing intensity" from an intense UV excitation. Further, by characterizing the role of relevant monomer molecular orbitals, we arrive at a design principle that allows us to predict the presence or absence of an additional absorption based on the bonding geometry of the dimer. We find this rule correctly explains the spectra of a wide range of acene derivatives and solves an unexplained structure-spectrum phenomenon first observed over 70 years ago. These results pave the way for the design of highly absorbent chromophores with applications ranging from photovoltaics to liquid crystals.
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Affiliation(s)
- Timothy J H Hele
- Cavendish Laboratory , Cambridge University , JJ Thomson Avenue , Cambridge CB3 0HE , U.K
| | - Eric G Fuemmeler
- Baker Laboratory , Cornell University , 259 East Avenue , Ithaca , New York 14850 , United States
| | - Samuel N Sanders
- Department of Chemistry , Columbia University , New York , New York 10027 , United States
| | - Elango Kumarasamy
- Department of Chemistry , Columbia University , New York , New York 10027 , United States
| | - Matthew Y Sfeir
- Center for Functional Nanomaterials , Brookhaven National Laboratory , Upton , New York 11973 , United States
| | - Luis M Campos
- Department of Chemistry , Columbia University , New York , New York 10027 , United States
| | - Nandini Ananth
- Baker Laboratory , Cornell University , 259 East Avenue , Ithaca , New York 14850 , United States
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31
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Korovina NV, Joy J, Feng X, Feltenberger C, Krylov AI, Bradforth SE, Thompson ME. Linker-Dependent Singlet Fission in Tetracene Dimers. J Am Chem Soc 2018; 140:10179-10190. [PMID: 30016102 DOI: 10.1021/jacs.8b04401] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Separation of triplet excitons produced by singlet fission is crucial for efficient application of singlet fission materials. While earlier works explored the first step of singlet fission, the formation of the correlated triplet pair state, the focus of recent studies has been on understanding the second step of singlet fission, the formation of independent triplets from the correlated pair state. We present the synthesis and excited-state dynamics of meta- and para-bis(ethynyltetracenyl)benzene dimers that are analogues to the ortho-bis(ethynyltetracenyl)benzene dimer reported by our groups previously. A comparison of the excited-state properties of these dimers allows us to investigate the effects of electronic conjugation and coupling on singlet fission between the ethynyltetracene units within a dimer. In the para isomer, in which the two chromophores are conjugated, the singlet exciton yields the correlated triplet pair state, from which the triplet excitons can decouple via molecular rotations. In contrast, the meta isomer in which the two chromophores are cross-coupled predominantly relaxes via radiative decay. We also report the synthesis and excited-state dynamics of two para dimers with different bridging units joining the ethynyltetracenes. The rate of singlet fission is found to be faster in the dimer with the bridging unit that has orbitals closer in energy to that of the ethynyltetracene chromophores.
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Affiliation(s)
- Nadezhda V Korovina
- Department of Chemistry , University of Southern California , Los Angeles , California 90089 , United States
| | - Jimmy Joy
- Department of Chemistry , University of Southern California , Los Angeles , California 90089 , United States
| | - Xintian Feng
- Department of Chemistry , University of Southern California , Los Angeles , California 90089 , United States
| | - Cassidy Feltenberger
- Department of Chemistry , University of Southern California , Los Angeles , California 90089 , United States
| | - Anna I Krylov
- Department of Chemistry , University of Southern California , Los Angeles , California 90089 , United States
| | - Stephen E Bradforth
- Department of Chemistry , University of Southern California , Los Angeles , California 90089 , United States
| | - Mark E Thompson
- Department of Chemistry , University of Southern California , Los Angeles , California 90089 , United States
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32
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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: 742] [Impact Index Per Article: 123.7] [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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33
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Yamakado T, Takahashi S, Watanabe K, Matsumoto Y, Osuka A, Saito S. Conformational Planarization versus Singlet Fission: Distinct Excited‐State Dynamics of Cyclooctatetraene‐Fused Acene Dimers. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201802185] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Takuya Yamakado
- Department of Chemistry Graduate School of Science Kyoto University Sakyo-ku Kyoto 606-8502 Japan
| | - Shota Takahashi
- Department of Chemistry Graduate School of Science Kyoto University Sakyo-ku Kyoto 606-8502 Japan
| | - Kazuya Watanabe
- Department of Chemistry Graduate School of Science Kyoto University Sakyo-ku Kyoto 606-8502 Japan
| | - Yoshiyasu Matsumoto
- Department of Chemistry Graduate School of Science Kyoto University Sakyo-ku Kyoto 606-8502 Japan
| | - Atsuhiro Osuka
- Department of Chemistry Graduate School of Science Kyoto University Sakyo-ku Kyoto 606-8502 Japan
| | - Shohei Saito
- Department of Chemistry Graduate School of Science Kyoto University Sakyo-ku Kyoto 606-8502 Japan
- JST-PRESTO FRONTIER Japan
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34
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Yamakado T, Takahashi S, Watanabe K, Matsumoto Y, Osuka A, Saito S. Conformational Planarization versus Singlet Fission: Distinct Excited-State Dynamics of Cyclooctatetraene-Fused Acene Dimers. Angew Chem Int Ed Engl 2018. [PMID: 29516597 DOI: 10.1002/anie.201802185] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A set of flapping acene dimers fused with an 8π cyclooctatetraene (COT) ring showed distinct excited-state dynamics in solution. While the anthracene dimer showed a fast V-shaped-to-planar conformational change within 10 ps in the lowest excited singlet state, reminding us of extended Baird aromaticity, the tetracene dimer and the pentacene dimer underwent intramolecular singlet fission (SF) in different manners: A fast and reversible SF with a characteristic delayed fluorescence (FL), and a fast and quantitative SF, respectively. Conformational flexibility of the fused COT linkage plays an important role in these ultrafast dynamics, demonstrating the utility of the flapping molecular series as a versatile platform for designing photofunctional systems.
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Affiliation(s)
- Takuya Yamakado
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Shota Takahashi
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Kazuya Watanabe
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Yoshiyasu Matsumoto
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Atsuhiro Osuka
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Shohei Saito
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan.,JST-PRESTO, FRONTIER, Japan
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35
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Structure and dynamics of triplet-exciton pairs generated from singlet fission studied via magnetic field effects. Commun Chem 2018. [DOI: 10.1038/s42004-018-0008-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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36
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Pace NA, Arias DH, Granger DB, Christensen S, Anthony JE, Johnson JC. Dynamics of singlet fission and electron injection in self-assembled acene monolayers on titanium dioxide. Chem Sci 2018; 9:3004-3013. [PMID: 29732084 PMCID: PMC5915837 DOI: 10.1039/c7sc04688j] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 02/15/2018] [Indexed: 12/11/2022] Open
Abstract
We employ a combination of linear spectroscopy, electrochemistry, and transient absorption spectroscopy to characterize the interplay between electron transfer and singlet fission dynamics in polyacene-based dyes attached to nanostructured TiO2. For triisopropyl silylethynyl (TIPS)-pentacene, we find that the singlet fission time constant increases to 6.5 ps on a nanostructured TiO2 surface relative to a thin film time constant of 150 fs, and that triplets do not dissociate after they are formed. In contrast, TIPS-tetracene singlets quickly dissociate in 2 ps at the molecule/TiO2 interface, and this dissociation outcompetes the relatively slow singlet fission process. The addition of an alumina layer slows down electron injection, allowing the formation of triplets from singlet fission in 40 ps. However, the triplets do not inject electrons, which is likely due to a lack of sufficient driving force for triplet dissociation. These results point to the critical balance required between efficient singlet fission and appropriate energetics for interfacial charge transfer.
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Affiliation(s)
- Natalie A Pace
- National Renewable Energy Laboratory , Golden , CO 80401 , USA .
- Department of Chemistry and Biochemistry , University of Colorado , Boulder , CO 80309 , USA
| | - Dylan H Arias
- National Renewable Energy Laboratory , Golden , CO 80401 , USA .
| | - Devin B Granger
- Department of Chemistry , University of Kentucky , Lexington , KY 40506 , USA
| | | | - John E Anthony
- Department of Chemistry , University of Kentucky , Lexington , KY 40506 , USA
| | - Justin C Johnson
- National Renewable Energy Laboratory , Golden , CO 80401 , USA .
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37
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Hetzer C, Guldi DM, Tykwinski RR. Pentacene Dimers as a Critical Tool for the Investigation of Intramolecular Singlet Fission. Chemistry 2018; 24:8245-8257. [DOI: 10.1002/chem.201705355] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Constantin Hetzer
- Department of Chemistry and Pharmacy; Interdisciplinary Center for Molecular Materials (ICMM); Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU); Nikolaus-Fiebiger-Straße 10 91058 Erlangen Germany
| | - Dirk M. Guldi
- Department of Chemistry and Pharmacy; Interdisciplinary Center for Molecular Materials (ICMM); Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU); Egerlandstrasse 3 91058 Erlangen Germany
| | - Rik R. Tykwinski
- Department of Chemistry; University of Alberta; Edmonton Alberta T6G 2G2 Canada
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38
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Ito S, Nagami T, Nakano M. Molecular design for efficient singlet fission. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS 2018. [DOI: 10.1016/j.jphotochemrev.2018.01.002] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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39
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Carey TJ, Miller EG, Gilligan AT, Sammakia T, Damrauer NH. Modular Synthesis of Rigid Polyacene Dimers for Singlet Fission. Org Lett 2018; 20:457-460. [DOI: 10.1021/acs.orglett.7b03817] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Thomas J. Carey
- Department of Chemistry and
Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Ethan G. Miller
- Department of Chemistry and
Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Alexander T. Gilligan
- Department of Chemistry and
Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Tarek Sammakia
- Department of Chemistry and
Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Niels H. Damrauer
- Department of Chemistry and
Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
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40
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Le AK, Bender JA, Arias DH, Cotton DE, Johnson JC, Roberts ST. Singlet Fission Involves an Interplay between Energetic Driving Force and Electronic Coupling in Perylenediimide Films. J Am Chem Soc 2018; 140:814-826. [DOI: 10.1021/jacs.7b11888] [Citation(s) in RCA: 136] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Aaron K. Le
- Department
of Chemistry, The University of Texas at Austin, Austin, Texas 78712-1224, United States
| | - Jon A. Bender
- Department
of Chemistry, The University of Texas at Austin, Austin, Texas 78712-1224, United States
| | - Dylan H. Arias
- National Renewable Energy Laboratory, Golden, Colorado 80401-3305, United States
| | - Daniel E. Cotton
- Department
of Chemistry, The University of Texas at Austin, Austin, Texas 78712-1224, United States
| | - Justin C. Johnson
- National Renewable Energy Laboratory, Golden, Colorado 80401-3305, United States
| | - Sean T. Roberts
- Department
of Chemistry, The University of Texas at Austin, Austin, Texas 78712-1224, United States
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41
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Wang X, Wang R, Shen L, Tang Z, Wen C, Dong B, Liu H, Zhang C, Li X. Intramolecular singlet fission in a face-to-face stacked tetracene trimer. Phys Chem Chem Phys 2018; 20:6330-6336. [DOI: 10.1039/c7cp07841b] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Efficient intramolecular singlet fission can be achieved in a “face-to-face” stacked tetracene trimer.
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Affiliation(s)
- Xuemin Wang
- College of Science
- China University of Petroleum (East China)
- Qingdao
- China
| | - Rui Wang
- National Laboratory of Solid State Microstructures & School of Physics
- Nanjing University
- Nanjing 210093
- China
| | - Li Shen
- College of Science
- China University of Petroleum (East China)
- Qingdao
- China
| | - Zhaofeng Tang
- College of Science
- China University of Petroleum (East China)
- Qingdao
- China
| | - Congying Wen
- College of Science
- China University of Petroleum (East China)
- Qingdao
- China
| | - Bin Dong
- College of Science
- China University of Petroleum (East China)
- Qingdao
- China
| | - Heyuan Liu
- College of Science
- China University of Petroleum (East China)
- Qingdao
- China
| | - Chunfeng Zhang
- National Laboratory of Solid State Microstructures & School of Physics
- Nanjing University
- Nanjing 210093
- China
| | - Xiyou Li
- College of Science
- China University of Petroleum (East China)
- Qingdao
- China
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42
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Tokoro Y, Ohtsuka N, Fukuzawa SI, Oyama T. Intra- and intermolecular interaction of anthracene moieties in 7,8-disilabicyclo[3.3.0]octadienyl-bridged bisanthracenes. RSC Adv 2018; 8:25177-25180. [PMID: 35542129 PMCID: PMC9082342 DOI: 10.1039/c8ra05293j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 07/06/2018] [Indexed: 11/21/2022] Open
Abstract
V-shaped 9-anthrylarylsilane dimers prepared through ruthenium-catalyzed C–H cleavage showed excimer emission and bathochromic shifts by promoted contact of π-orbitals.
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Affiliation(s)
- Yuichiro Tokoro
- Department of Advanced Materials Chemistry
- Faculty of Engineering
- Yokohama National University
- Hodogaya-ku, Yokohama
- 240-8501 Japan
| | - Nobuhiko Ohtsuka
- Department of Applied Chemistry
- Institute of Science and Engineering
- Chuo University
- Tokyo
- Japan
| | - Shin-ichi Fukuzawa
- Department of Applied Chemistry
- Institute of Science and Engineering
- Chuo University
- Tokyo
- Japan
| | - Toshiyuki Oyama
- Department of Advanced Materials Chemistry
- Faculty of Engineering
- Yokohama National University
- Hodogaya-ku, Yokohama
- 240-8501 Japan
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43
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Cook JD, Carey TJ, Arias DH, Johnson JC, Damrauer NH. Solvent-Controlled Branching of Localized versus Delocalized Singlet Exciton States and Equilibration with Charge Transfer in a Structurally Well-Defined Tetracene Dimer. J Phys Chem A 2017; 121:9229-9242. [DOI: 10.1021/acs.jpca.7b09458] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jasper D. Cook
- Department
of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - Thomas J. Carey
- Department
of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - Dylan H. Arias
- National Renewable Energy Laboratory, Golden, Colorado 80401, United States
| | - Justin C. Johnson
- National Renewable Energy Laboratory, Golden, Colorado 80401, United States
| | - Niels H. Damrauer
- Department
of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, United States
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44
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Kumarasamy E, Sanders SN, Tayebjee MJY, Asadpoordarvish A, Hele TJH, Fuemmeler EG, Pun AB, Yablon LM, Low JZ, Paley DW, Dean JC, Choi B, Scholes GD, Steigerwald ML, Ananth N, McCamey DR, Sfeir MY, Campos LM. Tuning Singlet Fission in π-Bridge-π Chromophores. J Am Chem Soc 2017; 139:12488-12494. [PMID: 28799752 DOI: 10.1021/jacs.7b05204] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
We have designed a series of pentacene dimers separated by homoconjugated or nonconjugated bridges that exhibit fast and efficient intramolecular singlet exciton fission (iSF). These materials are distinctive among reported iSF compounds because they exist in the unexplored regime of close spatial proximity but weak electronic coupling between the singlet exciton and triplet pair states. Using transient absorption spectroscopy to investigate photophysics in these molecules, we find that homoconjugated dimers display desirable excited-state dynamics, with significantly reduced recombination rates as compared to conjugated dimers with similar singlet fission rates. In addition, unlike conjugated dimers, the time constants for singlet fission are relatively insensitive to the interplanar angle between chromophores, since rotation about σ bonds negligibly affects the orbital overlap within the π-bonding network. In the nonconjugated dimer, where the iSF occurs with a time constant >10 ns, comparable to the fluorescence lifetime, we used electron spin resonance spectroscopy to unequivocally establish the formation of triplet-triplet multiexcitons and uncoupled triplet excitons through singlet fission. Together, these studies enable us to articulate the role of the conjugation motif in iSF.
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Affiliation(s)
| | | | - Murad J Y Tayebjee
- Cavendish Laboratory, University of Cambridge , J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | | | - Timothy J H Hele
- Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14850, United States.,Jesus College, Cambridge University , Cambridge CB5 8BL, United Kingdom
| | - Eric G Fuemmeler
- Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14850, United States
| | | | | | | | | | - Jacob C Dean
- Department of Chemistry, Princeton University , Princeton, New Jersey 08544, United States
| | | | - Gregory D Scholes
- Department of Chemistry, Princeton University , Princeton, New Jersey 08544, United States
| | | | - Nandini Ananth
- Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14850, United States
| | | | - Matthew Y Sfeir
- Center for Functional Nanomaterials, Brookhaven National Laboratory , Upton, New York 11973, United States
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45
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Carey TJ, Snyder JL, Miller EG, Sammakia T, Damrauer NH. Synthesis of Geometrically Well-Defined Covalent Acene Dimers for Mechanistic Exploration of Singlet Fission. J Org Chem 2017; 82:4866-4874. [DOI: 10.1021/acs.joc.7b00602] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Thomas J. Carey
- Department of Chemistry and
Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Jamie L. Snyder
- Department of Chemistry and
Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Ethan G. Miller
- Department of Chemistry and
Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Tarek Sammakia
- Department of Chemistry and
Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Niels H. Damrauer
- Department of Chemistry and
Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
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46
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Liu H, Wang R, Shen L, Xu Y, Xiao M, Zhang C, Li X. A Covalently Linked Tetracene Trimer: Synthesis and Singlet Exciton Fission Property. Org Lett 2017; 19:580-583. [DOI: 10.1021/acs.orglett.6b03739] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Heyuan Liu
- College
of Science, China University of Petroleum (East China), Qingdao, Shandong 266580, China
| | - Rui Wang
- National
Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
| | - Li Shen
- College
of Science, China University of Petroleum (East China), Qingdao, Shandong 266580, China
| | - Yanqing Xu
- National
Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
| | - Min Xiao
- National
Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
- Synergetic
Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Chunfeng Zhang
- National
Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
- Synergetic
Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiyou Li
- College
of Science, China University of Petroleum (East China), Qingdao, Shandong 266580, China
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47
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Bettinger HF, Einholz R, Göttler A, Junge M, Sättele MS, Schnepf A, Schrenk C, Schundelmeier S, Speiser B. 6,6′,11,11′-Tetra((triisopropylsilyl)ethynyl)-anti-[2.2](1,4)tetracenophane: a covalently coupled tetracene dimer and its structural, electrochemical, and photophysical characterization. Org Chem Front 2017. [DOI: 10.1039/c7qo00117g] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
[2.2]-Acenophanes are a class of compounds with two acene units interconnected by two ethano bridges.
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Affiliation(s)
| | - Ralf Einholz
- Institut für Organische Chemie
- Universität Tübingen
- 72076 Tübingen
- Germany
| | - Andreas Göttler
- Institut für Organische Chemie
- Universität Tübingen
- 72076 Tübingen
- Germany
| | - Marc Junge
- Institut für Organische Chemie
- Universität Tübingen
- 72076 Tübingen
- Germany
| | | | - Andreas Schnepf
- Institut für Anorganische Chemie
- Universität Tübingen
- 72076 Tübingen
- Germany
| | - Claudio Schrenk
- Institut für Anorganische Chemie
- Universität Tübingen
- 72076 Tübingen
- Germany
| | | | - Bernd Speiser
- Institut für Organische Chemie
- Universität Tübingen
- 72076 Tübingen
- Germany
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48
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Ito S, Nagami T, Nakano M. Rational design of doubly-bridged chromophores for singlet fission and triplet–triplet annihilation. RSC Adv 2017. [DOI: 10.1039/c7ra06032g] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A novel multiple-bridging realizes rational molecular design for efficient singlet fission and triplet–triplet annihilation.
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Affiliation(s)
- S. Ito
- Department of Materials Engineering Science
- Graduate School of Engineering Science
- Osaka University
- Toyonaka
- Japan
| | - T. Nagami
- Department of Materials Engineering Science
- Graduate School of Engineering Science
- Osaka University
- Toyonaka
- Japan
| | - M. Nakano
- Department of Materials Engineering Science
- Graduate School of Engineering Science
- Osaka University
- Toyonaka
- Japan
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49
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Zeng T. Through-Linker Intramolecular Singlet Fission: General Mechanism and Designing Small Chromophores. J Phys Chem Lett 2016; 7:4405-4412. [PMID: 27759395 DOI: 10.1021/acs.jpclett.6b02131] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We perform quantum chemistry calculations and quantum dynamics simulations to investigate the covalent linker's through-bond effects in intramolecular singlet fission. A model molecule with two diazadiborine chromophore units and the para-phenylene linker is proposed. A general, step-by-step picture for the conversion from the single- to the multiexcitonic state through the linker is presented. On the basis of the picture, we discuss the triplet-pair delocalization into the linker and design two more chromophores with higher fission efficiency. All three designed chromophores have promising picosecond fission time scales and make good candidates for azaborine synthesis.
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Affiliation(s)
- Tao Zeng
- Department of Chemistry, Carleton University , Ottawa, Ontario K1S5B6, Canada
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