1
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Pamungkas KKP, Fureraj I, Assies L, Sakai N, Mercier V, Chen XX, Vauthey E, Matile S. Core-Alkynylated Fluorescent Flippers: Altered Ultrafast Photophysics to Track Thick Membranes. Angew Chem Int Ed Engl 2024:e202406204. [PMID: 38758302 DOI: 10.1002/anie.202406204] [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: 04/01/2024] [Revised: 05/06/2024] [Accepted: 05/16/2024] [Indexed: 05/18/2024]
Abstract
Fluorescent flippers have been introduced as small-molecule probes to image membrane tension in living systems. This study describes the design, synthesis, spectroscopic and imaging properties of flippers that are elongated by one and two alkynes inserted between the push and the pull dithienothiophene domains. The resulting mechanophores combine characteristics of flippers, reporting on physical compression in the ground state, and molecular rotors, reporting on torsional motion in the excited state, to take their photophysics to new level of sophistication. Intensity ratios in broadened excitation bands from differently twisted conformers of core-alkynylated flippers thus report on mechanical compression. Lifetime boosts from ultrafast excited-state planarization and lifetime drops from competitive intersystem crossing into triplet states report on viscosity. In standard lipid bilayer membranes, core-alkynylated flippers are too long for one leaflet and tilt or extend into disordered interleaflet space, which preserves rotor-like torsional disorder and thus weak, blue-shifted fluorescence. Flipper-like planarization occurs only in highly ordered membranes of matching leaflet thickness, where they light up and selectively report on these thick membranes with red-shifted, sharpened excitation maxima, high intensity and long lifetime.
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Affiliation(s)
| | - Ina Fureraj
- Department of Physical Chemistry, University of Geneva, Geneva, Switzerland
| | - Lea Assies
- Department of Organic Chemistry, University of Geneva, Geneva, Switzerland
| | - Naomi Sakai
- Department of Organic Chemistry, University of Geneva, Geneva, Switzerland
| | | | - Xiao-Xiao Chen
- Department of Organic Chemistry, University of Geneva, Geneva, Switzerland
| | - Eric Vauthey
- Department of Physical Chemistry, University of Geneva, Geneva, Switzerland
| | - Stefan Matile
- Department of Organic Chemistry, University of Geneva, Geneva, Switzerland
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2
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Roy R, Chawla S, Sharma V, Pal AK, Silori Y, Datta A, De AK, Koner AL. Ultrafast symmetry-breaking charge separation in Perylenemonoimide-embedded multichromophores: impact of regioisomerism. Chem Sci 2024; 15:6363-6377. [PMID: 38699268 PMCID: PMC11062123 DOI: 10.1039/d3sc05325c] [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: 10/09/2023] [Accepted: 03/20/2024] [Indexed: 05/05/2024] Open
Abstract
Symmetry-breaking charge separation (SB-CS) has recently evolved as an emerging concept offering its potential to the latest generation of organic photovoltaics. However there are several concerns that need to be addressed to reach the state-of-the-art in SB-CS chemistry, for instance, the desirable molecular geometry, interchromophoric distance and extent of electronic coupling. To shed light on those features, it is reported herein, that ortho-functionalized perylene monoimide (PMI) constituted regioisomeric dimer and trimer derivatives with varied molecular twisting and electronic conjugation have been synthesized. In steady-state photophysical studies, all the dimers and trimer derivatives exhibit a larger bathochromic shift in the emission spectra and a significant reduction of fluorescence quantum yield in polar DMF. Among the series of multichromophores, ortho- and self-coupled dimers display the strikingly different optical feature of SB-CS with a very fast charge separation rate (τCS = 80.2 ps) upon photoexcitation in DMF, which is unveiled by femtosecond transient absorption (fs-TA) studies. The SB-CS for two dimers is well-supported by the formation of PMI˙+ and PMI˙- bands in the fs-TA spectra. Further analysis of fs-TA data revealed that, among the other multichromophores the trimer also exhibits a clear charge separation, whereas SB-CS signatures are less prominent, but can not be completely disregarded, for the meta- and para-dimers. Additionally, the charge separation dynamics of those above-mentioned PMI derivatives are devoid of a kinetically favorable excimer or triplet formation. The evidence of a profound charge transfer phenomenon in the ortho-dimer is characterized by density functional theory (DFT) calculations on excited state electronic structures. The excitonic communications in the excited state electronic arrangements unravel the key role of dihedral twisting in SB-CS. The thermodynamic feasibility of CS (ΔGCS) and activation barrier (ΔG≠) of the derivatives in DMF are established from the Rehm-Weller equation and Marcus's theory, respectively. This work is an in-depth study of the effect of mutual orientation of PMIs and regioisomerism in determining sustainable guidelines for using SB-CS.
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Affiliation(s)
- Rupam Roy
- Bionanotechnology Lab, Department of Chemistry, Indian Institute of Science Education and Research Bhopal Bhopal Bypass Road, Bhauri Bhopal Madhya Pradesh 462066 India
| | - Sakshi Chawla
- Condensed Phase Dynamics Group, Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali Knowledge City, Sector 81, SAS Nagar Punjab 140 306 India
| | - Vikas Sharma
- Bionanotechnology Lab, Department of Chemistry, Indian Institute of Science Education and Research Bhopal Bhopal Bypass Road, Bhauri Bhopal Madhya Pradesh 462066 India
| | - Arun K Pal
- School of Chemical Sciences, Indian Association for the Cultivation of Science 2A and 2B Raja S. C. Mullick Road, Jadavpur Kolkata West Bengal 700032 India
| | - Yogita Silori
- Condensed Phase Dynamics Group, Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali Knowledge City, Sector 81, SAS Nagar Punjab 140 306 India
- Department of Physics, University of Michigan Ann Arbor Michigan 48109 USA
| | - Ayan Datta
- School of Chemical Sciences, Indian Association for the Cultivation of Science 2A and 2B Raja S. C. Mullick Road, Jadavpur Kolkata West Bengal 700032 India
| | - Arijit K De
- Condensed Phase Dynamics Group, Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali Knowledge City, Sector 81, SAS Nagar Punjab 140 306 India
| | - Apurba Lal Koner
- Bionanotechnology Lab, Department of Chemistry, Indian Institute of Science Education and Research Bhopal Bhopal Bypass Road, Bhauri Bhopal Madhya Pradesh 462066 India
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3
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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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4
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Wega J, Zhang KF, Lacour J, Vauthey E. Controlling Symmetry-Breaking Charge Separation in Pyrene Bichromophores. J Phys Chem Lett 2024:2834-2840. [PMID: 38442038 DOI: 10.1021/acs.jpclett.4c00337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
So far, symmetry-breaking charge separation (SB-CS) has been observed with a limited number of chromophores and is usually inhibited by the formation of an excimer. , We show here that thanks to of fine-tuning of the interchromophore coupling via structural control, SB-CS can be operative with pyrene, despite its high propensity to form an excimer. This is realized with a bichromophoric system consisting of two pyrenes attached to a crown ether macrocycle, which can bind cations of different sizes. By combining stationary and time-resolved spectroscopy together with molecular dynamics simulations, we demonstrate that the excited-state dynamics can be totally changed depending on the binding cation. Whereas strong coupling leads to rapid excimer formation, too weak coupling results in noninteracting chromophores. However, intermediate coupling, achieved upon binding of Mg2+, allows for SB-CS to be operative.
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5
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Jing R, Li Y, Tajima K, Wan Y, Fukui N, Shinokubo H, Kuang Z, Xia A. Excimer Formation Driven by Excited-State Structural Relaxation in a Covalent Aminonaphthalimide Dimer. J Phys Chem Lett 2024; 15:1469-1476. [PMID: 38295158 DOI: 10.1021/acs.jpclett.3c03337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2024]
Abstract
Strongly coupled excimer formation from interchromophoric charge transfer driven by the ultrafast excited-state structural dynamics of a 5,5'-linked 4-amino-1,8-naphthalimide covalent homodimer was investigated by ultrafast transient spectroscopy and chemical calculations. Theoretical calculations indicate that the structural relaxation associated with the dihedral motion leads to significantly enhanced interchromophoric charge transfer (CT) coupling, which favors the formation of an excimer-like symmetry-broken CT state. The formation and relaxation dynamics of the excimer state in the dimer are identified via ultrafast transient absorption and fluorescence spectroscopy. The structural relaxation following the photoexcitation occurs in tens of picoseconds and stabilizes the dimer to the strongly coupled excimer state. The highly polar solvents further stabilize the excimer state and enhance the CT character, which enable efficient electron and excitation energy transport in covalent molecular aggregates.
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Affiliation(s)
- Rui Jing
- State Key Laboratory of Information Photonic and Optical Communications and School of Science, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876, P. R. China
| | - Yang Li
- State Key Laboratory of Information Photonic and Optical Communications and School of Science, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876, P. R. China
| | - Keita Tajima
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
| | - Yan Wan
- College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Norihito Fukui
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
| | - Hiroshi Shinokubo
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
| | - Zhuoran Kuang
- State Key Laboratory of Information Photonic and Optical Communications and School of Science, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876, P. R. China
| | - Andong Xia
- State Key Laboratory of Information Photonic and Optical Communications and School of Science, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876, P. R. China
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6
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Verma P, Budkina DS, Vauthey E. Photoinduced Electron Transfer between Dipolar Reactants: Solvent and Excitation Wavelength Effects. J Phys Chem B 2024; 128:1231-1240. [PMID: 38265415 DOI: 10.1021/acs.jpcb.3c07922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2024]
Abstract
Electron transfer (ET) quenching in nonpolar media is not as well understood as in polar environments. Here, we investigate the effect of dipole-dipole interactions between the reactants using ultrafast broadband electronic spectroscopy combined with molecular dynamics simulations. We find that the quenching of the S1 state of two polar dyes, coumarin 152a and Nile red, by the polar N,N-dimethylaniline (DMA) in cyclohexane is faster by a factor up to 3 when exciting on the red edge rather than at the maximum of their S1 ← S0 absorption band. This originates from the inhomogeneous broadening of the band due to a distribution of the number of quencher molecules around the dyes. As a consequence, red-edge excitation photoselects dyes in a DMA-rich environment. Such broadening is not present in acetonitrile, and no excitation wavelength dependence of the ET dynamics is observed. The quenching of both dyes is markedly faster in nonpolar than polar solvents, independently of the excitation wavelength. According to molecular dynamics simulations, this is due to the preferential solvation of the dyes by DMA in cyclohexane. The opposite preferential solvation is predicted in acetonitrile. Consequently, close contact between the reactants in acetonitrile requires partial desolvation. By contrast, the recombination of the quenching product is slower in nonpolar than in polar solvents and exhibits much smaller dependence, if any, on the excitation wavelength.
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Affiliation(s)
- Pragya Verma
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, 1211 Geneva, Switzerland
| | - Darya S Budkina
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, 1211 Geneva, Switzerland
| | - Eric Vauthey
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, 1211 Geneva, Switzerland
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7
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Pál D, Lacour J. Pfeiffer effect on configurationally labile dyes within ternary complexes with metal ions and enantiopure macrocycles. Dalton Trans 2024; 53:2665-2669. [PMID: 38224291 PMCID: PMC10845008 DOI: 10.1039/d3dt04098d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 01/10/2024] [Indexed: 01/16/2024]
Abstract
A configurationally-labile helical dye, 2,4,5,7-tetranitrofluorenone oximate, is used to probe complexes made of enantiopure macrocycles and mono/divalent metal ions. Induced electronic circular dichroism (ECD) and 1H NMR responses are amplified at room temperature only in the presence of K+ and Na+ ions despite larger binding efficiency with alkaline earth metal ions.
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Affiliation(s)
- Dávid Pál
- Department of Organic Chemistry, University of Geneva, Quai Ernest Ansermet 30, CH-1211 Geneva, Switzerland.
| | - Jérôme Lacour
- Department of Organic Chemistry, University of Geneva, Quai Ernest Ansermet 30, CH-1211 Geneva, Switzerland.
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8
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Yahagh A, Kaswan RR, Kazemi S, Karr PA, D'Souza F. Symmetry breaking charge transfer leading to charge separation in a far-red absorbing bisstyryl-BODIPY dimer. Chem Sci 2024; 15:906-913. [PMID: 38239676 PMCID: PMC10793208 DOI: 10.1039/d3sc05034c] [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: 09/23/2023] [Accepted: 12/14/2023] [Indexed: 01/22/2024] Open
Abstract
Symmetry breaking charge transfer is one of the important photo-events occurring in photosynthetic reaction centers that is responsible for initiating electron transfer leading to a long-lived charge-separated state and has been successfully employed in light-to-electricity converting optoelectronic devices. In the present study, we report a newly synthesized, far-red absorbing and emitting BODIPY-dimer to undergo symmetry-breaking charge transfer leading to charge-separated states of appreciable lifetimes in polar solvents. Compared to its monomer analog, both steady-state and time-resolved fluorescence originating from the S1 state of the dimer revealed quenching which increased with an increase in solvent polarity. The electrostatic potential map from DFT and the time-dependent DFT calculations suggested the existence of a quadrupolar type charge transfer state in polar solvents, and the singlet excited state to be involved in the charge separation process. The electrochemically determined redox gap being smaller than the energy of the S1 state supported the thermodynamic feasibility of the envisioned symmetry-breaking charge transfer and separation. The spectrum of the charge-separated state arrived from spectroelectrochemical studies, revealing diagnostic peaks helpful for transient spectral interpretation. Finally, ultrafast transient pump-probe spectroscopy provided conclusive evidence of diabatic charge separation in polar solvents by far-red pulsed laser light irradiation. The measured lifetime of the final charge-separated states was found to be 165 ps in dichlorobenzene, 140 ps in benzonitrile, and 43 ps in dimethyl sulfoxide, revealing their significance in light energy harvesting, especially from the less-explored far-red region.
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Affiliation(s)
- Aida Yahagh
- Department of Chemistry, University of North Texas 1155 Union Circle #305070 Denton TX 76203-5017 USA
| | - Ram R Kaswan
- Department of Chemistry, University of North Texas 1155 Union Circle #305070 Denton TX 76203-5017 USA
| | - Shahrzad Kazemi
- Department of Chemistry, University of North Texas 1155 Union Circle #305070 Denton TX 76203-5017 USA
| | - Paul A Karr
- Department of Physical Sciences and Mathematics, Wayne State College 111 Main Street Wayne NE 68787 USA
| | - Francis D'Souza
- Department of Chemistry, University of North Texas 1155 Union Circle #305070 Denton TX 76203-5017 USA
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9
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Wega J, Vauthey E. Bimolecular photoinduced symmetry-breaking charge separation of perylene in solution. Photochem Photobiol Sci 2024; 23:93-105. [PMID: 38133700 PMCID: PMC10834668 DOI: 10.1007/s43630-023-00504-3] [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: 09/25/2023] [Accepted: 11/05/2023] [Indexed: 12/23/2023]
Abstract
Photoinduced symmetry-breaking charge separation (SB-CS) results in the generation of charge carriers through electron transfer between two identical molecules, after photoexcitation of one of them. It is usually studied in systems where the two reacting moieties are covalently linked. Examples of photoinduced bimolecular SB-CS with organic molecules yielding free ions remain scarce due to solubility or aggregation issues at the high concentrations needed to study this diffusion-assisted process. Here we investigate the excited-state dynamics of perylene (Pe) at high concentrations in solvents of varying polarity. Transient absorption spectroscopy on the subnanosecond to microsecond timescales reveal that self-quenching of Pe in the lowest singlet excited state leads to excimer formation in all solvents used. Additionally, bimolecular SB-CS, resulting in the generation of free ions, occurs concurrently to excimer formation in polar media, with a relative efficiency that increases with the polarity of the solvent. Moreover, we show that SB-CS is most efficient in room-temperature ionic liquids due to a charge-shielding effect leading to a larger escape of ions and due to the high viscosity that disfavours excimer formation.
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Affiliation(s)
- Johannes Wega
- Department of Physical Chemistry, University of Geneva, Quai Ernest Ansermet 30, 1205, Geneva, Switzerland
| | - Eric Vauthey
- Department of Physical Chemistry, University of Geneva, Quai Ernest Ansermet 30, 1205, Geneva, Switzerland.
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10
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Bradley JM, Coleman AF, Brown PJ, Huang Y, Young RM, Wasielewski MR. Harvesting electrons and holes from photodriven symmetry-breaking charge separation within a perylenediimide photosynthetic model dimer. Proc Natl Acad Sci U S A 2023; 120:e2313575120. [PMID: 37983509 PMCID: PMC10691211 DOI: 10.1073/pnas.2313575120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 10/11/2023] [Indexed: 11/22/2023] Open
Abstract
Understanding how to utilize symmetry-breaking charge separation (SB-CS) offers a path toward increasingly efficient light-harvesting technologies. This process plays a central role in the first step of photosynthesis, in which the dimeric "special pair" of the photosynthetic reaction center enters a coherent SB-CS state after photoexcitation. Previous research on SB-CS in both biological and synthetic chromophore dimers has focused on increasing the efficiency of light-driven processes. In a chromophore dimer undergoing SB-CS, the energy of the radical ion pair product is nearly isoenergetic with that of the lowest excited singlet (S1) state of the dimer. This means that very little energy is lost from the absorbed photon. In principle, the relatively high energy electron and hole generated by SB-CS within the chromophore dimer can each be transferred to adjacent charge acceptors to extend the lifetime of the electron-hole pair, which can increase the efficiency of solar energy conversion. To investigate this possibility, we have designed a bis-perylenediimide cyclophane (mPDI2) covalently linked to a secondary electron donor, peri-xanthenoxanthene (PXX) and a secondary electron acceptor, partially fluorinated naphthalenediimide (FNDI). Upon selective photoexcitation of mPDI2, transient absorption spectroscopy shows that mPDI2 undergoes SB-CS, followed by two secondary charge transfer reactions to generate a PXX•+-mPDI2-FNDI•- radical ion pair having a nearly 3 µs lifetime. This strategy has the potential to increase the efficiency of molecular systems for artificial photosynthesis and photovoltaics.
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Affiliation(s)
- Jillian M. Bradley
- Department of Chemistry, Northwestern University, Evanston, IL60208-3113
- Paula M. Trienens Institute for Sustainability and Energy, Northwestern University, Evanston, IL60208-3113
| | - Adam F. Coleman
- Department of Chemistry, Northwestern University, Evanston, IL60208-3113
- Paula M. Trienens Institute for Sustainability and Energy, Northwestern University, Evanston, IL60208-3113
| | - Paige J. Brown
- Department of Chemistry, Northwestern University, Evanston, IL60208-3113
- Paula M. Trienens Institute for Sustainability and Energy, Northwestern University, Evanston, IL60208-3113
| | - Yuheng Huang
- Department of Chemistry, Northwestern University, Evanston, IL60208-3113
- Paula M. Trienens Institute for Sustainability and Energy, Northwestern University, Evanston, IL60208-3113
| | - Ryan M. Young
- Department of Chemistry, Northwestern University, Evanston, IL60208-3113
- Paula M. Trienens Institute for Sustainability and Energy, Northwestern University, Evanston, IL60208-3113
| | - Michael R. Wasielewski
- Department of Chemistry, Northwestern University, Evanston, IL60208-3113
- Paula M. Trienens Institute for Sustainability and Energy, Northwestern University, Evanston, IL60208-3113
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11
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Maret PD, Sasikumar D, Sebastian E, Hariharan M. Symmetry-Breaking Charge Separation in a Chiral Bis(perylenediimide) Probed at Ensemble and Single-Molecule Levels. J Phys Chem Lett 2023; 14:8667-8675. [PMID: 37733055 DOI: 10.1021/acs.jpclett.3c01889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
Chiral molecular assemblies exhibiting symmetry-breaking charge separation (SB-CS) are potential candidates for the development of chiral organic semiconductors. Herein, we explore the excited-state dynamics of a helically chiral perylenediimide bichromophore (Cy-PDI2) exhibiting SB-CS at the ensemble and single-molecule levels. Solvent polarity-tunable interchromophoric excitonic coupling in chiral Cy-PDI2 facilitates the interplay of SB-CS and excimer formation in the ensemble domain. Analogous to the excited-state dynamics of Cy-PDI2 at the ensemble level, single-molecule fluorescence lifetime traces of Cy-PDI2 depicted long-lived off-states characteristic of the radical ion pair-mediated dark states. The discrete electron transfer and charge separation dynamics in Cy-PDI2 at the single-molecule level are governed by the distinct influence of the local environment. The present study aims at understanding the fundamental excited-state dynamics in chiral organic bichromophores for designing efficient chiral organic semiconductors and applications toward charge transport materials.
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Affiliation(s)
- Philip Daniel Maret
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala P.O., Vithura, Thiruvananthapuram, Kerala 695551, India
| | - Devika Sasikumar
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala P.O., Vithura, Thiruvananthapuram, Kerala 695551, India
| | - Ebin Sebastian
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala P.O., Vithura, Thiruvananthapuram, Kerala 695551, India
| | - Mahesh Hariharan
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala P.O., Vithura, Thiruvananthapuram, Kerala 695551, India
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12
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Zhang M, Johnson CE, Ilic A, Schwarz J, Johansson MB, Lomoth R. High-Efficiency Photoinduced Charge Separation in Fe(III)carbene Thin Films. J Am Chem Soc 2023; 145:19171-19176. [PMID: 37616472 PMCID: PMC10485928 DOI: 10.1021/jacs.3c05404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Indexed: 08/26/2023]
Abstract
Symmetry-breaking charge separation in molecular materials has attracted increasing attention for optoelectronics based on single-material active layers. To this end, Fe(III) complexes with particularly electron-donating N-heterocyclic carbene ligands offer interesting properties with a 2LMCT excited state capable of oxidizing or reducing the complex in its ground state. In this Communication, we show that the corresponding symmetry-breaking charge separation occurs in amorphous films of pristine [Fe(III)L2]PF6 (L = [phenyl(tris(3-methylimidazol-2-ylidene))borate]-). Excitation of the solid material with visible light leads to ultrafast electron transfer quenching of the 2LMCT excited state, generating Fe(II) and Fe(IV) products with high efficiency. Sub-picosecond charge separation followed by recombination in about 1 ns could be monitored by transient absorption spectroscopy. Photoconductivity measurements of films deposited on microelectrode arrays demonstrated that photogenerated charge carriers can be collected at external contacts.
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Affiliation(s)
- Minli Zhang
- Department
of Chemistry - Ångström Laboratory, Uppsala University, Box 523, SE-75120 Uppsala, Sweden
| | - Catherine E. Johnson
- Department
of Chemistry - Ångström Laboratory, Uppsala University, Box 523, SE-75120 Uppsala, Sweden
| | - Aleksandra Ilic
- Center
for Analysis and Synthesis, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Jesper Schwarz
- Center
for Analysis and Synthesis, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Malin B. Johansson
- Department
of Chemistry - Ångström Laboratory, Uppsala University, Box 523, SE-75120 Uppsala, Sweden
| | - Reiner Lomoth
- Department
of Chemistry - Ångström Laboratory, Uppsala University, Box 523, SE-75120 Uppsala, Sweden
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13
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Del Pino Rosendo E, Yildiz O, Pisula W, Marszalek T, Blom PWM, Ramanan C. Symmetry-breaking charge transfer and intersystem crossing in copper phthalocyanine thin films. Phys Chem Chem Phys 2023; 25:6847-6856. [PMID: 36799358 DOI: 10.1039/d2cp05240g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Intermolecular interactions in π-stacked chromophores strongly influence their photophysical properties, and thereby also their function in photonic applications. Mixed electronic and vibrational coupling interactions lead to complex potential energy landscapes with competitive photophysical pathways. Here, we characterize the photoexcited dynamics of the small molecule semiconductor copper pthalocyanine (CuPc) in solution and in thin film, the latter comprising two different π-stacked architectures, α-CuPc and β-CuPc. In solution, CuPc undergoes ultrafast intersytem crossing (ISC) to the triplet excited state. In the solid state, both α-CuPc and β-CuPc morphologies exhibit a mixing between Frenkel and charge-transfer excitons (Frenkel-CT mixing). We find that this mixing influences the photophysical properties differently, based on morphology. In addition to ISC, α-CuPc demonstrates symmetry-breaking charge transfer, which furthermore depends on excitation wavelength. This mechanism is not observed in β-CuPc. These results elucidate how molecular organization mediates the balance of competitive photexcited decay mechanisms in organic semiconductors.
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Affiliation(s)
| | - Okan Yildiz
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, DE, Germany
| | - Wojciech Pisula
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, DE, Germany.,Department of Molecular Physics, Faculty of Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland
| | - Tomasz Marszalek
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, DE, Germany.,Department of Molecular Physics, Faculty of Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland
| | - Paul W M Blom
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, DE, Germany
| | - Charusheela Ramanan
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, DE, Germany.,Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
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14
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Swathi K, Sujith M, Divya PS, P MV, Delledonne A, Phan Huu DKA, Di Maiolo F, Terenziani F, Lapini A, Painelli A, Sissa C, Thomas KG. From symmetry breaking to symmetry swapping: is Kasha's rule violated in multibranched phenyleneethynylenes? Chem Sci 2023; 14:1986-1996. [PMID: 36845926 PMCID: PMC9945429 DOI: 10.1039/d2sc05206g] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Accepted: 01/12/2023] [Indexed: 01/15/2023] Open
Abstract
The phenomenon of excited-state symmetry breaking is often observed in multipolar molecular systems, significantly affecting their photophysical and charge separation behavior. As a result of this phenomenon, the electronic excitation is partially localized in one of the molecular branches. However, the intrinsic structural and electronic factors that regulate excited-state symmetry breaking in multibranched systems have hardly been investigated. Herein, we explore these aspects by adopting a joint experimental and theoretical investigation for a class of phenyleneethynylenes, one of the most widely used molecular building blocks for optoelectronic applications. The large Stokes shifts observed for highly symmetric phenyleneethynylenes are explained by the presence of low-lying dark states, as also established by two-photon absorption measurements and TDDFT calculations. In spite of the presence of low-lying dark states, these systems show an intense fluorescence in striking contrast to Kasha's rule. This intriguing behavior is explained in terms of a novel phenomenon, dubbed "symmetry swapping" that describes the inversion of the energy order of excited states, i.e., the swapping of excited states occurring as a consequence of symmetry breaking. Thus, symmetry swapping explains quite naturally the observation of an intense fluorescence emission in molecular systems whose lowest vertical excited state is a dark state. In short, symmetry swapping is observed in highly symmetric molecules having multiple degenerate or quasi-degenerate excited states that are prone to symmetry breaking.
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Affiliation(s)
- K. Swathi
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di ParmaParco Area delle Scienze 17A43124ParmaItaly,School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM)VithuraThiruvananthapuram695 551India
| | - Meleppatt Sujith
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM) Vithura Thiruvananthapuram 695 551 India
| | - P. S. Divya
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM)VithuraThiruvananthapuram695 551India
| | - Merin Varghese P
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM) Vithura Thiruvananthapuram 695 551 India
| | - Andrea Delledonne
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma Parco Area delle Scienze 17A 43124 Parma Italy
| | - D. K. Andrea Phan Huu
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di ParmaParco Area delle Scienze 17A43124ParmaItaly
| | - Francesco Di Maiolo
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma Parco Area delle Scienze 17A 43124 Parma Italy
| | - Francesca Terenziani
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma Parco Area delle Scienze 17A 43124 Parma Italy
| | - Andrea Lapini
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma Parco Area delle Scienze 17A 43124 Parma Italy
| | - Anna Painelli
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma Parco Area delle Scienze 17A 43124 Parma Italy
| | - Cristina Sissa
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma Parco Area delle Scienze 17A 43124 Parma Italy
| | - K. George Thomas
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM)VithuraThiruvananthapuram695 551India
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15
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Ma L, Kuang Z, Wang Z, Zhao H, Wan Y, Zhang XF, Li Y, Xia A. Ultrafast Charge Separation Driven by Torsional Motion in Orthogonal Boron Dipyrromethene Dimer. J Phys Chem Lett 2023; 14:702-708. [PMID: 36646067 DOI: 10.1021/acs.jpclett.2c03581] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
In this work, the photoinduced charge separation (CS) via symmetry breaking in an orthogonal meso-β-linked boron dipyrromethene (BODIPY) dimer was investigated by polarized transient absorption spectroscopy. The time constant about 0.76 ps of the CS reaction determined in dimethyl sulfoxide is much faster than the solvation dynamics. The observed transient anisotropy of the BODIPY anion band implies that both hole and electron transfers occur with similar probabilities. The bidirectional charge transfer processes suggest that the locally excited state is weakly coupled to the polar solvent, and the solvation coupled excited-state structural relaxation within the BODIPY monomeric unit is rather limited. In combination with the electronic excitation analysis based on time-dependent density-functional theory calculations, we deduced that the CS in the orthogonal BODIPY dimer is enabled via the torsional motion associated with covalently connected BODIPY units, promoting the electronic coupling, and irrelevant to the dynamic solvent relaxation.
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Affiliation(s)
- Lin Ma
- State Key Laboratory of Information Photonic and Optical Communications and School of Science, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876, People's Republic of China
| | - Zhuoran Kuang
- State Key Laboratory of Information Photonic and Optical Communications and School of Science, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876, People's Republic of China
| | - Zeming Wang
- State Key Laboratory of Information Photonic and Optical Communications and School of Science, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876, People's Republic of China
| | - Hongmei Zhao
- State Key Laboratory of Information Photonic and Optical Communications and School of Science, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876, People's Republic of China
| | - Yan Wan
- College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Xian-Fu Zhang
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, People's Republic of China
| | - Yang Li
- State Key Laboratory of Information Photonic and Optical Communications and School of Science, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876, People's Republic of China
| | - Andong Xia
- State Key Laboratory of Information Photonic and Optical Communications and School of Science, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876, People's Republic of China
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16
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Hart SM, Banal JL, Castellanos MA, Markova L, Vyborna Y, Gorman J, Häner R, Willard AP, Bathe M, Schlau-Cohen GS. Activating charge-transfer state formation in strongly-coupled dimers using DNA scaffolds. Chem Sci 2022; 13:13020-13031. [PMID: 36425503 PMCID: PMC9667922 DOI: 10.1039/d2sc02759c] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 10/04/2022] [Indexed: 09/16/2023] Open
Abstract
Strongly-coupled multichromophoric assemblies orchestrate the absorption, transport, and conversion of photonic energy in natural and synthetic systems. Programming these functionalities involves the production of materials in which chromophore placement is precisely controlled. DNA nanomaterials have emerged as a programmable scaffold that introduces the control necessary to select desired excitonic properties. While the ability to control photophysical processes, such as energy transport, has been established, similar control over photochemical processes, such as interchromophore charge transfer, has not been demonstrated in DNA. In particular, charge transfer requires the presence of close-range interchromophoric interactions, which have a particularly steep distance dependence, but are required for eventual energy conversion. Here, we report a DNA-chromophore platform in which long-range excitonic couplings and short-range charge-transfer couplings can be tailored. Using combinatorial screening, we discovered chromophore geometries that enhance or suppress photochemistry. We combined spectroscopic and computational results to establish the presence of symmetry-breaking charge transfer in DNA-scaffolded squaraines, which had not been previously achieved in these chromophores. Our results demonstrate that the geometric control introduced through the DNA can access otherwise inaccessible processes and program the evolution of excitonic states of molecular chromophores, opening up opportunities for designer photoactive materials for light harvesting and computation.
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Affiliation(s)
- Stephanie M Hart
- Department of Chemistry, Massachusetts Institute of Technology Cambridge MA 02139 USA
| | - James L Banal
- Department of Biological Engineering, Massachusetts Institute of Technology Cambridge MA 02139 USA
| | - Maria A Castellanos
- Department of Chemistry, Massachusetts Institute of Technology Cambridge MA 02139 USA
| | - Larysa Markova
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern Freiestrasse 3, CH-3012 Bern Switzerland
| | - Yuliia Vyborna
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern Freiestrasse 3, CH-3012 Bern Switzerland
| | - Jeffrey Gorman
- Department of Biological Engineering, Massachusetts Institute of Technology Cambridge MA 02139 USA
| | - Robert Häner
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern Freiestrasse 3, CH-3012 Bern Switzerland
| | - Adam P Willard
- Department of Chemistry, Massachusetts Institute of Technology Cambridge MA 02139 USA
| | - Mark Bathe
- Department of Biological Engineering, Massachusetts Institute of Technology Cambridge MA 02139 USA
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17
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Homberg A, Navazio F, Le Tellier A, Zinna F, Fürstenberg A, Besnard C, Di Bari L, Lacour J. Circularly polarized luminescence from Tb(III) interacting with chiral polyether macrocycles. Dalton Trans 2022; 51:16479-16485. [PMID: 36218085 PMCID: PMC9641584 DOI: 10.1039/d2dt02627a] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 10/04/2022] [Indexed: 10/14/2023]
Abstract
A straightforward two-step synthesis protocol affords a series of chiral amide-based bis-pyridine substituted polyether macrocycles. One ligand is particularly able to complex terbium(III) ions spontaneously. Upon complexation, interesting chiroptical properties are observed both in absorbance (ECD) and in fluorescence (CPL). In ligand-centered electronic circular dichroism, a sign inversion coupled with a signal enhancement is measured; while an easily detectable metal-centered circularly polarized luminescence with a glum of 0.05 is obtained for the main 5D4 → 7F5 terbium transition. The coordination mode and structure of the complex was studied using different analysis methods (NMR analysis, spectrophotometric titration and solid-state elucidation).
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Affiliation(s)
- Alexandre Homberg
- Department of Organic Chemistry, University of Geneva, Quai Ernest Ansermet 30, 1211 Geneva 4, Switzerland.
| | - Federica Navazio
- Department of Organic Chemistry, University of Geneva, Quai Ernest Ansermet 30, 1211 Geneva 4, Switzerland.
- School of Science and Technology, Chemistry Division, University of Camerino, via S. Agostino n. 1, 62032 Camerino, Italy
| | - Antoine Le Tellier
- Department of Organic Chemistry, University of Geneva, Quai Ernest Ansermet 30, 1211 Geneva 4, Switzerland.
| | - Francesco Zinna
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Moruzzi 13, 56124 Pisa, Italy
| | - Alexandre Fürstenberg
- Department of Inorganic and Analytical Chemistry, University of Geneva, 1211 Geneva, Switzerland
- Department of Physical Chemistry, University of Geneva, 1211 Geneva, Switzerland
| | - Céline Besnard
- Laboratory of Crystallography, University of Geneva, Quai Ernest Ansermet 24, 1211 Geneva 4, Switzerland
| | - Lorenzo Di Bari
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Moruzzi 13, 56124 Pisa, Italy
| | - Jérôme Lacour
- Department of Organic Chemistry, University of Geneva, Quai Ernest Ansermet 30, 1211 Geneva 4, Switzerland.
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18
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Fureraj I, Budkina DS, Vauthey E. Torsional disorder and planarization dynamics: 9,10-bis(phenylethynyl)anthracene as a case study. Phys Chem Chem Phys 2022; 24:25979-25989. [PMID: 36263805 PMCID: PMC9627944 DOI: 10.1039/d2cp03909e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 10/04/2022] [Indexed: 06/14/2023]
Abstract
Conjugated molecules with phenylethynyl building blocks are usually characterised by torsional disorder at room temperature. They are much more rigid in the electronic excited state due to conjugation. As a consequence, the electronic absorption and emission spectra do not present a mirror-image relationship. Here, we investigate how torsional disorder affects the excited state dynamics of 9,10-bis(phenylethynyl)anthracene in solvents of different viscosities and in polymers, using both stationary and ultrafast electronic spectroscopies. Temperature-dependent measurements reveal inhomogeneous broadening of the absorption spectrum at room temperature. This is confirmed by ultrafast spectroscopic measurements at different excitation wavelengths. Red-edge irradiation excites planar molecules that return to the ground state without significant structural dynamics. In this case, however, re-equilibration of the torsional disorder in the ground state can be observed. Higher-energy irradiation excites torsionally disordered molecules, which then planarise, leading to important spectral dynamics. The latter is found to occur partially via viscosity-independent inertial motion, whereas it is purely diffusive in the ground state. This dissimilarity is explained in terms of the steepness of the potential along the torsional coordinate.
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Affiliation(s)
- Ina Fureraj
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, CH-1211 Geneva 4, Switzerland.
| | - Darya S Budkina
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, CH-1211 Geneva 4, Switzerland.
| | - Eric Vauthey
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, CH-1211 Geneva 4, Switzerland.
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19
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Brückmann J, Müller C, Friedländer I, Mengele AK, Peneva K, Dietzek‐Ivanšić B, Rau S. Photocatalytic Reduction of Nicotinamide Co-factor by Perylene Sensitized Rh III Complexes. Chemistry 2022; 28:e202201931. [PMID: 35920047 PMCID: PMC9825842 DOI: 10.1002/chem.202201931] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Indexed: 01/11/2023]
Abstract
The ambitious goal of artificial photosynthesis is to develop active systems that mimic nature and use light to split water into hydrogen and oxygen. Intramolecular design concepts are particularly promising. Herein, we firstly present an intramolecular photocatalyst integrating a perylene-based light-harvesting moiety and a catalytic rhodium center (RhIII phenPer). The excited-state dynamics were investigated by means of steady-state and time-resolved absorption and emission spectroscopy. The studies reveal that photoexcitation of RhIII phenPer yields the formation of a charge-separated intermediate, namely RhII phenPer⋅+ , that results in a catalytically active species in the presence of protons.
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Affiliation(s)
- Jannik Brückmann
- Institute of Inorganic Chemistry IUlm UniversityAlbert-Einstein-Allee 1189081UlmGermany
| | - Carolin Müller
- Institute of Physical ChemistryFriedrich Schiller University JenaHelmholtzweg 407743JenaGermany,Research Department Functional InterfacesLeibniz Institute of Photonic Technology JenaAlbert-Einstein-Straße 907745JenaGermany
| | - Ilse Friedländer
- Institute of Physical ChemistryFriedrich Schiller University JenaHelmholtzweg 407743JenaGermany
| | - Alexander K. Mengele
- Institute of Inorganic Chemistry IUlm UniversityAlbert-Einstein-Allee 1189081UlmGermany
| | - Kalina Peneva
- Institute of Organic Chemistry and Macromolecular ChemistryFriedrich Schiller University JenaLessingstraße 807743JenaGermany,Center for Energy and Environmental Chemistry Jena (CEEC Jena)Friedrich Schiller University JenaPhilosophenweg 7a07743JenaGermany
| | - Benjamin Dietzek‐Ivanšić
- Institute of Physical ChemistryFriedrich Schiller University JenaHelmholtzweg 407743JenaGermany,Research Department Functional InterfacesLeibniz Institute of Photonic Technology JenaAlbert-Einstein-Straße 907745JenaGermany,Center for Energy and Environmental Chemistry Jena (CEEC Jena)Friedrich Schiller University JenaPhilosophenweg 7a07743JenaGermany
| | - Sven Rau
- Institute of Inorganic Chemistry IUlm UniversityAlbert-Einstein-Allee 1189081UlmGermany
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20
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Sebastian E, Sunny J, Hariharan M. Excimer evolution hampers symmetry-broken charge-separated states. Chem Sci 2022; 13:10824-10835. [PMID: 36320683 PMCID: PMC9491171 DOI: 10.1039/d2sc04387d] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Accepted: 08/18/2022] [Indexed: 08/26/2023] Open
Abstract
Achieving long-lived symmetry-broken charge-separated states in chromophoric assemblies is quintessential for enhanced performance of artificial photosynthetic mimics. However, the occurrence of energy trap states hinders exciton and charge transport across photovoltaic devices, diminishing power conversion efficiency. Herein, we demonstrate unprecedented excimer formation in the relaxed excited-state geometry of bichromophoric systems impeding the lifetime of symmetry-broken charge-separated states. Core-annulated perylenediimide dimers (SC-SPDI2 and SC-NPDI2) prefer a near-orthogonal arrangement in the ground state and a π-stacked foldamer structure in the excited state. The prospect of an excimer-like state in the foldameric arrangement of SC-SPDI2 and SC-NPDI2 has been rationalized by fragment-based excited state analysis and temperature-dependent photoluminescence measurements. Effective electronic coupling matrix elements in the Franck-Condon geometry of SC-SPDI2 and SC-NPDI2 facilitate solvation-assisted ultrafast symmetry-breaking charge-separation (SB-CS) in a high dielectric environment, in contrast to unrelaxed excimer formation (Ex*) in a low dielectric environment. Subsequently, the SB-CS state dissociates into an undesired relaxed excimer state (Ex) due to configuration mixing of a Frenkel exciton (FE) and charge-separated state in the foldamer structure, downgrading the efficacy of the charge-separated state. The decay rate constant of the FE to SB-CS (k FE→SB-CS) in polar solvents is 8-17 fold faster than that of direct Ex* formation (k FE→Ex*) in non-polar solvent (k FE→SB-CS≫k FE→Ex*), characterized by femtosecond transient absorption (fsTA) spectroscopy. The present investigation establishes the impact of detrimental excimer formation on the persistence of the SB-CS state in chromophoric dimers and offers the requisite of conformational rigidity as one of the potential design principles for developing advanced molecular photovoltaics.
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Affiliation(s)
- Ebin Sebastian
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram Maruthamala P.O., Vithura Thiruvananthapuram Kerala 695551 India
| | - Jeswin Sunny
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram Maruthamala P.O., Vithura Thiruvananthapuram Kerala 695551 India
| | - Mahesh Hariharan
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram Maruthamala P.O., Vithura Thiruvananthapuram Kerala 695551 India
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21
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Hong Y, Schlosser F, Kim W, Würthner F, Kim D. Ultrafast Symmetry-Breaking Charge Separation in a Perylene Bisimide Dimer Enabled by Vibronic Coupling and Breakdown of Adiabaticity. J Am Chem Soc 2022; 144:15539-15548. [PMID: 35951363 DOI: 10.1021/jacs.2c03916] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Perylene bisimides (PBIs) have received great attention in their applicability to optoelectronics. Especially, symmetry-breaking charge separation (SB-CS) in PBIs has been investigated to mimic the efficient light capturing and charge generation in natural light-harvesting systems. However, unlike ultrafast CS dynamics in donor-acceptor heterojunction materials, ultrafast SB-CS in a stacked homodimer has still been challenging due to excimer formation in the absence of rigidifying surroundings such as a special pair in the natural systems. Herein, we present the detailed mechanism of ultrafast photoinduced SB-CS occurring in a 1,7-bis(N-pyrrolidinyl) PBI dimer within a cyclophane. Through narrow-band and broad-band transient absorption spectroscopy, we demonstrate that ultrafast SB-CS in the dimer is enabled by the combination of (1) vibrationally coherent charge-transfer resonance-enhanced excimer formation and (2) breakdown of adiabaticity (formation of SB-CS diabats) in the excimer state via structural and solvent fluctuation. Quantum chemical calculations also underpin that the participation of strong electron-donating substituents in overall vibrational modes plays a crucial role in triggering the ultrafast SB-CS. Therefore, our work provides an alternative route to facilitate ultrafast SB-CS in PBIs and thereby establishes a novel strategy for the design of optoelectronic materials.
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Affiliation(s)
- Yongseok Hong
- Department of Chemistry, Yonsei University, Seoul 03722, Korea
| | - Felix Schlosser
- Institut für Organische Chemie & Center for Nanosystems Chemistry, Universitat Würzburg, Am Hubland, Würzburg 97074, Germany
| | - Woojae Kim
- Department of Chemistry, Yonsei University, Seoul 03722, Korea
| | - Frank Würthner
- Institut für Organische Chemie & Center for Nanosystems Chemistry, Universitat Würzburg, Am Hubland, Würzburg 97074, Germany
| | - Dongho Kim
- Department of Chemistry, Yonsei University, Seoul 03722, Korea.,Division of Energy Materials, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
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22
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Phan Huu DKA, Saseendran S, Dhali R, Franca LG, Stavrou K, Monkman A, Painelli A. Thermally Activated Delayed Fluorescence: Polarity, Rigidity, and Disorder in Condensed Phases. J Am Chem Soc 2022; 144:15211-15222. [PMID: 35944182 PMCID: PMC9413221 DOI: 10.1021/jacs.2c05537] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We present a detailed and comprehensive picture of the photophysics of thermally activated delayed fluorescence (TADF). The approach relies on a few-state model, parametrized ab initio on a prototypical TADF dye, that explicitly accounts for the nonadiabatic coupling between electrons and vibrational and conformational motion, crucial to properly address (reverse) intersystem crossing rates. The Onsager model is exploited to account for the medium polarity and polarizability, with careful consideration of the different time scales of relevant degrees of freedom. TADF photophysics is then quantitatively addressed in a coherent and exhaustive approach that accurately reproduces the complex temporal evolution of emission spectra in liquid solvents as well as in solid organic matrices. The different rigidity of the two environments is responsible for the appearance in matrices of important inhomogeneous broadening phenomena that are ascribed to the intertwined contribution from (quasi)static conformational and dielectric disorder.
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Affiliation(s)
- D K Andrea Phan Huu
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | - Sangeeth Saseendran
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | - Rama Dhali
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | | | - Kleitos Stavrou
- Department of Physics, Durham University, South Road, Durham DH1 3LE, U.K
| | - Andrew Monkman
- Department of Physics, Durham University, South Road, Durham DH1 3LE, U.K
| | - Anna Painelli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
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23
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Niu X, Tajima K, Kong J, Tao M, Fukui N, Kuang Z, Shinokubo H, Xia A. Symmetry-breaking charge separation in a nitrogen-bridged naphthalene monoimide dimer. Phys Chem Chem Phys 2022; 24:14007-14015. [PMID: 35635531 DOI: 10.1039/d2cp00295g] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The photophysical properties of 4-aminonaphthalene-1,8-imide-based derivatives, bis-ANI, consisting of two naphthalimide (NI) units linked by a butylamine bridge and its monomer ANI have been intensively investigated by steady-state and transient spectroscopy combined with quantum chemical calculations. The excited state relaxation dynamics of the two molecules are studied in three solvents of varying polarity - from hexane to tetrahydrofuran to acetone. A strong reduction in the fluorescence quantum yields and larger red shifts of the emission spectra are observed when going from the monomer ANI to dimer bis-ANI with increasing solvent polarity. It is found that the presence of the central amino linker in bis-ANI facilitates the formation of an asymmetric CS state between the ANI and NI moieties in bis-ANI, where NI˙- is the dominant radical anion unit after CS, evidenced by the femtosecond transient absorption measurements and spectroelectrochemistry in polar solvents. Femtosecond transient absorption spectra and quantum chemical calculations reveal the conformational change after the formation of the symmetry-breaking charge separation (SBCS) state upon photoexcitation, while a near-orthogonal structure in the excited state of bis-ANI retards charge recombination. In addition, it is evidenced that the rate of SBCS can be tuned by changing the different polar solvents.
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Affiliation(s)
- Xinmiao Niu
- State Key Laboratory of Information Photonic and Optical Communications, School of Science, Beijing University of Posts and Telecommunications (BUPT), Beijing 100176, P. R. China. .,Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Keita Tajima
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan.
| | - Jie Kong
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Min Tao
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Norihito Fukui
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan.
| | - Zhuoran Kuang
- State Key Laboratory of Information Photonic and Optical Communications, School of Science, Beijing University of Posts and Telecommunications (BUPT), Beijing 100176, P. R. China.
| | - Hiroshi Shinokubo
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan.
| | - Andong Xia
- State Key Laboratory of Information Photonic and Optical Communications, School of Science, Beijing University of Posts and Telecommunications (BUPT), Beijing 100176, P. R. China. .,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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24
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Estergreen L, Mencke AR, Cotton DE, Korovina NV, Michl J, Roberts ST, Thompson ME, Bradforth SE. Controlling Symmetry Breaking Charge Transfer in BODIPY Pairs. Acc Chem Res 2022; 55:1561-1572. [PMID: 35604637 DOI: 10.1021/acs.accounts.2c00044] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
ConspectusSymmetry breaking charge transfer (SBCT) is a process in which a pair of identical chromophores absorb a photon and use its energy to transfer an electron from one chromophore to the other, breaking the symmetry of the chromophore pair. This excited state phenomenon is observed in photosynthetic organisms where it enables efficient formation of separated charges that ultimately catalyze biosynthesis. SBCT has also been proposed as a means for developing photovoltaics and photocatalytic systems that operate with minimal energy loss. It is known that SBCT in both biological and artificial systems is in part made possible by the local environment in which it occurs, which can move to stabilize the asymmetric SBCT state. However, how environmental degrees of freedom act in concert with steric and structural constraints placed on a chromophore pair to dictate its ability to generate long-lived charge pairs via SBCT remain open topics of investigation.In this Account, we compare a broad series of dipyrrin dimers that are linked by distinct bridging groups to discern how the spatial separation and mutual orientation of linked chromophores and the structural flexibility of their linker each impact SBCT efficiency. Across this material set, we observe a general trend that SBCT is accelerated as the spatial separation between dimer chromophores decreases, consistent with the expectation that the electronic coupling between these units varies exponentially with their separation. However, one key observation is that the rate of charge recombination following SBCT was found to slow with decreasing interchromophore separation, rather than speed up. This stems from an enhancement of the dimer's structural rigidity due to increasing steric repulsion as the length of their linker shrinks. This rigidity further inhibits charge recombination in systems where symmetry has already enforced zero HOMO-LUMO overlap. Additionally, for the forward transfer, the active torsion is shown to increase LUMO-LUMO coupling, allowing for faster SBCT within bridging groups.By understanding trends for how rates of SBCT and charge recombination depend on a dimer's internal structure and its environment, we identify design guidelines for creating artificial systems for driving sustained light-induced charge separation. Such systems can find application in solar energy technologies and photocatalytic applications and can serve as a model for light-induced charge separation in biological systems.
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Affiliation(s)
- Laura Estergreen
- Department of Chemistry, University of Southern California, Los Angeles California 90089, United States
| | - Austin R. Mencke
- Department of Chemistry, University of Southern California, Los Angeles California 90089, United States
| | - Daniel E. Cotton
- Department of Chemistry, University of Texas at Austin, Austin Texas 78712, United States
| | - Nadia V. Korovina
- Department of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Josef Michl
- Department of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Sean T. Roberts
- Department of Chemistry, University of Texas at Austin, Austin Texas 78712, United States
| | - Mark E. Thompson
- 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
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25
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Wang K, Shao G, Peng S, You X, Chen X, Xu J, Huang H, Wang H, Wu D, Xia J. Achieving Symmetry-Breaking Charge Separation in Perylenediimide Trimers: The Effect of Bridge Resonance. J Phys Chem B 2022; 126:3758-3767. [PMID: 35559687 DOI: 10.1021/acs.jpcb.2c02387] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Symmetry-breaking charge separation (SB-CS) provides a very promising option to engineer a novel light conversion scheme, while it is still a challenge to realize SB-CS in a nonpolar environment. The strength of electronic coupling plays a crucial role in determining the exciton dynamics of organic semiconductors. Herein, we describe how to mediate interchromophore coupling to achieve SB-CS in a nonpolar solvent by the use of two perylenediimide (PDI)-based trimers, 1,7-tri-PDI and 1,6-tri-PDI. Although functionalization at the N-atom decreases electronic coupling between PDI units, our strategy takes advantage of "bridge resonance", in which the frontier orbital energies are nearly degenerate with those of the covalently linked PDI units, leading to enhanced interchromophore electronic coupling. Tunable electronic coupling was realized by the judicious combination of "bridge resonance" with N-functionalization. The enhanced mixing between the S1 state and CT/CS states results in direct observation of the CT band in the steady-state UV-vis absorption and negative free energy of charge separation (ΔGCS) in both chloroform and toluene for the two trimers. Using transient absorption spectroscopy, we demonstrated that photoinduced SB-CS in a nonpolar solvent is feasible. This work highlights that the use of "bridge resonance" is an effective way to control exciton dynamics of organic semiconductors.
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Affiliation(s)
- Kangwei Wang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan 430070, China
| | - Guangwei Shao
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan 430070, China
| | - Shaoqian Peng
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan 430070, China
| | - Xiaoxiao You
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan 430070, China
| | - Xingyu Chen
- International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China
| | - Jingwen Xu
- International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China
| | - Huaxi Huang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan 430070, China.,School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070, China
| | - Huan Wang
- International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China
| | - Di Wu
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan 430070, China.,School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070, China
| | - Jianlong Xia
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan 430070, China.,School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070, China
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26
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Hong Y, Kim W, Kim T, Kaufmann C, Kim H, Würthner F, Kim D. Real-time Observation of Structural Dynamics Triggering Excimer Formation in a Perylene Bisimide Folda-dimer by Ultrafast Time-Domain Raman Spectroscopy. Angew Chem Int Ed Engl 2022; 61:e202114474. [PMID: 35075813 PMCID: PMC9306572 DOI: 10.1002/anie.202114474] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Indexed: 01/31/2023]
Abstract
In π‐conjugated organic photovoltaic materials, an excimer state has been generally regarded as a trap state which hinders efficient excitation energy transport. But despite wide investigations of the excimer for overcoming the undesirable energy loss, the understanding of the relationship between the structure of the excimer in stacked organic compounds and its properties remains elusive. Here, we present the landscape of structural dynamics from the excimer formation to its relaxation in a co‐facially stacked archetypical perylene bisimide folda‐dimer using ultrafast time‐domain Raman spectroscopy. We directly captured vibrational snapshots illustrating the ultrafast structural evolution triggering the excimer formation along the interchromophore coordinate on the complex excited‐state potential surfaces and following evolution into a relaxed excimer state. Not only does this work showcase the ultrafast structural dynamics necessary for the excimer formation and control of excimer characteristics but also provides important criteria for designing the π‐conjugated organic molecules.
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Affiliation(s)
- Yongseok Hong
- Department of Chemistry, Spectroscopy Laboratory for Functional π-Electronic Systems, Yonsei University, 03722, Seoul, Republic of Korea
| | - Woojae Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional π-Electronic Systems, Yonsei University, 03722, Seoul, Republic of Korea.,Department of Chemistry and Chemical Biology, Cornell University, Ithaca, 14853, New York, USA
| | - Taeyeon Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional π-Electronic Systems, Yonsei University, 03722, Seoul, Republic of Korea.,The Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, 60208, Illinois, USA
| | - Christina Kaufmann
- Institut für Organische Chemie & Center for Nanosystems Chemistry, Universitat Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Hyungjun Kim
- Department of Chemistry, Incheon National University, 119 Academy-ro, Yeonsu-gu, 22012, Incheon, Republic of Korea
| | - Frank Würthner
- Institut für Organische Chemie & Center for Nanosystems Chemistry, Universitat Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Dongho Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional π-Electronic Systems, Yonsei University, 03722, Seoul, Republic of Korea
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27
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Seetharaman S, Zink‐Lorre N, Gutiérrez‐Moreno D, Karr PA, Fernández‐Lázaro F, D'Souza F. Quadrupolar Ultrafast Charge Transfer in Diaminoazobenzene‐Bridged Perylenediimide Triads. Chemistry 2022; 28:e202104574. [DOI: 10.1002/chem.202104574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Indexed: 11/06/2022]
Affiliation(s)
- Sairaman Seetharaman
- Department of Chemistry University of North Texas 1155 Union Circle, #305070 Denton TX 76203-5017 USA
| | - Nathalie Zink‐Lorre
- Área de Química Orgánica Instituto de Bioingeniería Universidad Miguel Hernández Avda. de la Universidad s/n 03202 Elche Spain
| | - David Gutiérrez‐Moreno
- Área de Química Orgánica Instituto de Bioingeniería Universidad Miguel Hernández Avda. de la Universidad s/n 03202 Elche Spain
| | - Paul A. Karr
- Department of Physical Sciences and Mathematics Wayne State College Wayne Nebraska 68787 USA
| | - Fernando Fernández‐Lázaro
- Área de Química Orgánica Instituto de Bioingeniería Universidad Miguel Hernández Avda. de la Universidad s/n 03202 Elche Spain
| | - Francis D'Souza
- Department of Chemistry University of North Texas 1155 Union Circle, #305070 Denton TX 76203-5017 USA
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28
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Hong Y, Kim W, Kim T, Kaufmann C, Kim H, Würthner F, Kim D. Real‐time Observation of Structural Dynamics Triggering Excimer Formation in a Perylene Bisimide Folda‐dimer by Ultrafast Time‐Domain Raman Spectroscopy. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202114474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Yongseok Hong
- Department of Chemistry Spectroscopy Laboratory for Functional π-Electronic Systems Yonsei University 03722 Seoul Republic of Korea
| | - Woojae Kim
- Department of Chemistry Spectroscopy Laboratory for Functional π-Electronic Systems Yonsei University 03722 Seoul Republic of Korea
- Department of Chemistry and Chemical Biology Cornell University Ithaca 14853 New York USA
| | - Taeyeon Kim
- Department of Chemistry Spectroscopy Laboratory for Functional π-Electronic Systems Yonsei University 03722 Seoul Republic of Korea
- The Institute for Sustainability and Energy at Northwestern Northwestern University Evanston 60208 Illinois USA
| | - Christina Kaufmann
- Institut für Organische Chemie & Center for Nanosystems Chemistry Universitat Würzburg Am Hubland 97074 Würzburg Germany
| | - Hyungjun Kim
- Department of Chemistry Incheon National University 119 Academy-ro, Yeonsu-gu 22012 Incheon Republic of Korea
| | - Frank Würthner
- Institut für Organische Chemie & Center for Nanosystems Chemistry Universitat Würzburg Am Hubland 97074 Würzburg Germany
| | - Dongho Kim
- Department of Chemistry Spectroscopy Laboratory for Functional π-Electronic Systems Yonsei University 03722 Seoul Republic of Korea
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29
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Beckwith JS, Aster A, Vauthey E. The excited-state dynamics of the radical anions of cyanoanthracenes. Phys Chem Chem Phys 2021; 24:568-577. [PMID: 34904984 PMCID: PMC8694058 DOI: 10.1039/d1cp04014f] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 11/29/2021] [Indexed: 12/03/2022]
Abstract
The radical anion of 9,10-dicyanoanthracene (DCA) has been suggested to be a promising chromophore for photoredox chemistry, due to its nanosecond excited-state lifetime determined from indirect measurements. Here, we investigate the excited-state dynamics of the radical anion of three cyanoanthracenes, including DCA˙-, produced by photoinduced electron transfer in liquid using both pump-probe and pump-pump probe transient electronic absorption spectroscopy. All three excited radical ions are characterised by a 3-5 ps lifetime, due to efficient non-radiative deactivation to the ground state. The decay pathway most probably involves D1/D0 conical intersection(s), whose presence is favoured by the enhanced flexibility of the radical anions relative to their neutral counterparts. The origin of the discrepancy with the nanosecond lifetime of DCA˙-* reported previously is discussed. These very short lifetimes limit, but do not preclude, photochemical applications of the cyanoanthracene anions.
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Affiliation(s)
- Joseph S Beckwith
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, CH-1211 Geneva 4, Switzerland.
| | - Alexander Aster
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, CH-1211 Geneva 4, Switzerland.
| | - Eric Vauthey
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, CH-1211 Geneva 4, Switzerland.
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30
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Zink‐Lorre N, Seetharaman S, Gutiérrez‐Moreno D, Fernández‐Lázaro F, Karr PA, D'Souza F. Excited State Charge Separation in an Azobenzene-Bridged Perylenediimide Dimer - Effect of Photochemical Trans-Cis Isomerization. Chemistry 2021; 27:14996-15005. [PMID: 34405918 PMCID: PMC8596671 DOI: 10.1002/chem.202102903] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Indexed: 01/26/2023]
Abstract
Photoinduced charge transfer and separation events in a newly synthesized azobenzene-bridged perylenediimide-dimer (PDI-dimer) are demonstrated. Trans-to-cis conversion (∼50 % efficiency) from the initial trans PDI-dimer by 355 nm pulsed laser light, and its reversal, cis-to-trans, process by 435 nm laser light irradiation has been possible to accomplish. Efficient fluorescence quenching in the PDI-dimer, more so for the cis isomer was witnessed, and such quenching increased with increasing solvent polarity. DFT-calculated geometry and electronic structures helped in visualizing the charge transfer in the PDI-dimer in both isomeric forms, and also revealed certain degree of participation of the azobenzene entity in the charge transfer events. Femtosecond transient absorption spectral studies confirmed occurrence of both charge transfer followed by charge separation in the studied PDI-dimer in both trans and cis forms in polar solvents, and the evaluated time constants from Global target analysis revealed accelerated events in the cis PDI-dimer due to proximity effects. The present study offers key insights on the role of the azobenzene bridge, and the dimer geometry in governing the excited state charge transfer and separation in symmetrically linked PDI dimer.
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Affiliation(s)
- Nathalie Zink‐Lorre
- Área de Química Orgánica, Instituto de BioingenieríaUniversidad Miguel Hernández de ElcheAvda. de la Universidad s/n03202ElcheSpain
| | - Sairaman Seetharaman
- Department of ChemistryUniversity of North Texas1155 Union Circle, #305070DentonTX 76203-5017USA
| | - David Gutiérrez‐Moreno
- Área de Química Orgánica, Instituto de BioingenieríaUniversidad Miguel Hernández de ElcheAvda. de la Universidad s/n03202ElcheSpain
| | - Fernando Fernández‐Lázaro
- Área de Química Orgánica, Instituto de BioingenieríaUniversidad Miguel Hernández de ElcheAvda. de la Universidad s/n03202ElcheSpain
| | - Paul A. Karr
- Department of Physical Sciences and MathematicsWayne State College1111 Main StreetWayneNebraska68787USA
| | - Francis D'Souza
- Department of ChemistryUniversity of North Texas1155 Union Circle, #305070DentonTX 76203-5017USA
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31
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Sebastian E, Hariharan M. Null Exciton-Coupled Chromophoric Dimer Exhibits Symmetry-Breaking Charge Separation. J Am Chem Soc 2021; 143:13769-13781. [PMID: 34370481 DOI: 10.1021/jacs.1c05793] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A comprehensive understanding of the structure-property relationships in multichromophoric architectures has pushed the limits for developing robust photosynthetic mimics and molecular photovoltaics. The elusive phenomenon of null exciton splitting has gathered immense attention in recent years owing to the occurrence in unique chromophoric architectures and consequent emergent properties. Herein, we unveil the hitherto unobserved null exciton coupling assisted highly efficient photoinduced symmetry-breaking charge separation (SB-CS) in a Greek cross (+)-oriented spiro-conjugated perylenediimide dimer (Sp-PDI2). Quantum chemical calculations have rationalized the infrequent manifestation of null exciton coupling behavior in Sp-PDI2. Negligible contribution of long-range Coulombic and short-range charge-transfer mediated coupling renders a monomer-like spectroscopic signature for Sp-PDI2 in toluene. The Greek cross (+)-arranged Sp-PDI2 possesses a selective hole-transfer coupling, facilitating the ultrafast dissociation of null excitons and evolution of the charge-separated state in polar solvents. Radical cationic and anionic spectroscopic signatures were characterized by employing femtosecond transient absorption spectroscopy. The substantial hole transfer electronic coupling and lower activation energy barrier of Sp-PDI2 accelerated the charge separation rate. The rate of charge recombination (CR) markedly decelerated due to falling into the inverted region of the Marcus parabola, where the driving force of CR is larger than the total reorganization energy for CR. Hence, the ratio of the rates for SB-CS over CR of Sp-PDI2 exhibited an unprecedently high value of 2647 in acetonitrile. The current study provides impeccable evidence for the role of selective charge filtering in governing efficient SB-CS and thereby novel insights towards the design of biomimics and advanced functional materials.
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Affiliation(s)
- Ebin Sebastian
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM), Maruthamala P.O., Vithura, Thiruvananthapuram 695551, Kerala, India
| | - Mahesh Hariharan
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM), Maruthamala P.O., Vithura, Thiruvananthapuram 695551, Kerala, India
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32
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Kaul N, Lomoth R. The Carbene Cannibal: Photoinduced Symmetry-Breaking Charge Separation in an Fe(III) N-Heterocyclic Carbene. J Am Chem Soc 2021; 143:10816-10821. [PMID: 34264638 PMCID: PMC8397313 DOI: 10.1021/jacs.1c03770] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
![]()
Photoinduced symmetry-breaking
charge separation (SB-CS) processes
offer the possibility of harvesting solar energy by electron transfer
between identical molecules. Here, we present the first case of direct
observation of bimolecular SB-CS in a transition metal complex, [FeIIIL2](PF6) (L = [phenyl(tris(3-methylimidazol-1-ylidene))borate]−). Photoexcitation of the complex in the visible region
results in the formation of a doublet ligand-to-metal charge transfer
(2LMCT) excited state (E0–0 = 2.13 eV), which readily reacts with the doublet ground state to
generate charge separated products, [FeIIL2]
and [FeIVL2]2+, with a measurable
cage escape yield. Known spectral signatures allow for unambiguous
identification of the products, whose formation and recombination
are monitored with transient absorption spectroscopy. The unusual
energetic landscape of [FeIIIL2]+, as reflected in its ground and excited state reduction potentials,
results in SB-CS being intrinsically exergonic (ΔGCS° ∼ −0.7 eV). This is in contrast
to most systems investigated in the literature, where ΔGCS° is close to zero, and the charge transfer
driven primarily by solvation effects. The study is therefore illustrative
for the utilization of the rich redox chemistry accessible in transition
metal complexes for the realization of SB-CS.
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Affiliation(s)
- Nidhi Kaul
- Department of Chemistry-Ångström Laboratory, Uppsala University, Box 523, SE-75120 Uppsala, Sweden
| | - Reiner Lomoth
- Department of Chemistry-Ångström Laboratory, Uppsala University, Box 523, SE-75120 Uppsala, Sweden
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33
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Bradley SJ, Chi M, White JM, Hall CR, Goerigk L, Smith TA, Ghiggino KP. The role of conformational heterogeneity in the excited state dynamics of linked diketopyrrolopyrrole dimers. Phys Chem Chem Phys 2021; 23:9357-9364. [PMID: 33885111 DOI: 10.1039/d1cp00541c] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Diketopyrrolopyrrole (DPP) derivatives have been proposed for both singlet fission and energy upconversion as they meet the energetic requirements and exhibit superior photostability compared to many other chromophores. In this study, both time-resolved electronic and IR spectroscopy have been applied to investigate excited state relaxation processes competing with fission in dimers of DPP derivatives with varying linker structures. A charge-separated (CS) state is shown to be an important intermediate with dynamics that are both solvent and linker dependent. The CS state is found for a subset of the total population of excited molecules and it is proposed that CS state formation requires suitably aligned dimers within a broader distribution of conformations available in solution. No long-lived triplet signatures indicative of singlet fission were detected, with the CS state likely acting as an alternative relaxation pathway for the excitation energy. This study provides insight into the role of molecular conformation in determining excited state relaxation pathways in DPP dimer systems.
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34
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Baghdasaryan A, Brun E, Wang Y, Salassa G, Lacour J, Bürgi T. Combined spectroscopic studies on post-functionalized Au 25 cluster as an ATR-FTIR sensor for cations. Chem Sci 2021; 12:7419-7427. [PMID: 34163832 PMCID: PMC8171333 DOI: 10.1039/d1sc01654g] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 04/20/2021] [Indexed: 11/21/2022] Open
Abstract
Recently, significant research activity has been devoted to thiolate-protected gold clusters due to their attractive optical and electronic properties. These properties as well as solubility and stability can be controlled by post-synthetic modification strategies. Herein, the ligand exchange reaction between Au25(2-PET)18 cluster (where 2-PET is 2-phenylethanethiol) and di-thiolated crown ether (t-CE) ligands bearing two chromophores was studied. The post-functionalization aimed to endow the cluster with ion binding properties. The exchange reaction was followed in situ by UV-vis, 1H NMR and HPLC. MALDI mass analysis revealed the incorporation of up to 5 t-CE ligands into the ligand shell. Once functionalized MALDI furthermore showed complexation of sodium ions to the cluster. ATR-FTIR spectroscopic studies using aqueous solutions of K+, Ba2+, Gd3+ and Eu3+ showed noticeable spectral shifts of the C-O stretching band around 1100 cm-1 upon complexation. Further spectral changes point towards a conformational change of the two chromophores that are attached to the crown ether. Density functional theory calculations indicate that the di-thiol ligand bridges two staple units on the cluster. The calculations furthermore reproduce the spectral shift of the C-O stretching vibrations upon complex formation and reveal a conformational change that involves the two chromophores attached to the crown ether. The functionalized clusters have therefore attractive ion sensing properties due to the combination of binding properties, mainly due to the crown ether, and the possibility for signal transduction via an induced conformational change involving chromophore units.
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Affiliation(s)
- Ani Baghdasaryan
- Department of Physical Chemistry, University of Geneva 30 Quai Ernest-Ansermet 1211 Geneva 4 Switzerland
| | - Elodie Brun
- Department of Organic Chemistry, University of Geneva 30 Quai Ernest-Ansermet 1211 Geneva 4 Switzerland
| | - Yuming Wang
- Department of Physical Chemistry, University of Geneva 30 Quai Ernest-Ansermet 1211 Geneva 4 Switzerland
| | - Giovanni Salassa
- Department of Physical Chemistry, University of Geneva 30 Quai Ernest-Ansermet 1211 Geneva 4 Switzerland
| | - Jérôme Lacour
- Department of Organic Chemistry, University of Geneva 30 Quai Ernest-Ansermet 1211 Geneva 4 Switzerland
| | - Thomas Bürgi
- Department of Physical Chemistry, University of Geneva 30 Quai Ernest-Ansermet 1211 Geneva 4 Switzerland
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35
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Shibasaki Y, Suenobu T, Nakagawa T, Katoh R. Effect of Deuteration on Relaxation Dynamics of the Perylene Excimer Studied by Subnanosecond Transient Absorption Spectroscopy. J Phys Chem A 2021; 125:1359-1366. [PMID: 33541078 DOI: 10.1021/acs.jpca.0c10683] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We studied the effect of deuteration on the relaxation dynamics of the excimer of perylene in solution using subnanosecond time-resolved transient absorption spectroscopy based on the randomly interleaved pulse-train method. We found that the deuterated perylene excimer in solution had a longer lifetime than the undeuterated excimer but that deuteration had a little effect on the ground-state and transient absorption spectra of the excimer, suggesting that deuteration altered the relaxation dynamics by inducing small changes in vibrational properties. To confirm the origin of the deuteration effect, we quantitatively analyzed the kinetics of transient absorption decay, including the decay of triplet-triplet absorption. In addition, we evaluated the effects of temperature on the lifetime of the excimers. On the basis of these results, we concluded that the rate of internal conversion was suppressed by deuteration. By comparing our results with previously reported results on the effect of deuteration on the fluorescence properties of crystalline perylene, we proposed a model that may explain the effect of deuteration on the lifetime of the perylene excimer in solution.
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Affiliation(s)
- Yuuya Shibasaki
- College of Engineering, Nihon University, Koriyama, Fukushima 963-8642, Japan
| | - Tomoyoshi Suenobu
- Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan
| | | | - Ryuzi Katoh
- College of Engineering, Nihon University, Koriyama, Fukushima 963-8642, Japan
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36
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Aster A, Zinna F, Rumble C, Lacour J, Vauthey E. Singlet Fission in a Flexible Bichromophore with Structural and Dynamic Control. J Am Chem Soc 2021; 143:2361-2371. [PMID: 33512153 DOI: 10.1021/jacs.0c12384] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Singlet fission (SF), i.e., the splitting of a high-energy exciton into two lower-energy triplet excitons, has the potential to increase the efficiency for harvesting spectrally broad light. The path from the photopopulated singlet state to free triplets is complicated by competing processes that decrease the overall SF efficiency. A detailed understanding of the whole cascade and the nature of the photoexcited singlet state is still a major challenge. Here, we introduce a pentacene dimer with a flexible crown ether spacer enabling a control of the interchromophore coupling upon solvent-induced self-aggregation as well as cation binding. The systematic change of solvent polarity and viscosity and excitation wavelength, as well as the available conformational phase space, allows us to draw a coherent picture of the whole SF cascade from the femtosecond to microsecond time scales. High coupling leads to ultrafast SF (<2 ps), independent of the solvent polarity, and to highly coupled correlated triplet pairs. The absence of a polarity effect indicates that the solvent coordinate does not play a significant role and that SF is driven by intramolecular modes. Low coupling results in much slower SF (∼500 ps), which depends on viscosity, and leads to weakly coupled correlated triplet pairs. These two triplet pairs could be spectrally distinguished and their contribution to the overall SF efficiency, i.e., to the population of free triplets, could be determined. Our results reveal how the overall SF efficiency can be increased by conformational restrictions and control of the structural fluctuation dynamics.
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Affiliation(s)
- Alexander Aster
- Department of Physical Chemistry, University of Geneva, CH-1211 Geneva, Switzerland
| | - Francesco Zinna
- Department of Organic Chemistry, University of Geneva, CH-1211 Geneva, Switzerland
| | - Christopher Rumble
- Department of Physical Chemistry, University of Geneva, CH-1211 Geneva, Switzerland
| | - Jérôme Lacour
- Department of Organic Chemistry, University of Geneva, CH-1211 Geneva, Switzerland
| | - Eric Vauthey
- Department of Physical Chemistry, University of Geneva, CH-1211 Geneva, Switzerland
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Kong J, Zhang W, Li G, Huo D, Guo Y, Niu X, Wan Y, Tang B, Xia A. Excited-State Symmetry-Breaking Charge Separation Dynamics in Multibranched Perylene Diimide Molecules. J Phys Chem Lett 2020; 11:10329-10339. [PMID: 33232151 DOI: 10.1021/acs.jpclett.0c03210] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
As one of the most promising nonfullerene acceptors for organic photovoltaics, perylene diimide (PDI)-based multibranched molecules with twisted or three-dimensional (3D) geometric structures have been developed, which effectively increase the power conversion efficiency (PCE) of organic solar cells. Understanding the structure-property relationships in multichromophoric molecular architectures at molecular and ultrafast time levels is a crucial step in establishing new design principles in organic electronic materials. For this, photodriven excited-state symmetry-breaking charge separation (SB-CS) of PDI-based multichromophoric acceptors has been proposed to improve the PCE by reducing the self-aggregation of the planar PDI monomer. Herein, we investigated the intramolecular excited-state SB-CS and charge recombination (CR) dynamics of two symmetric phenyl-methane-based PDI derivatives, a twist dimer PM-PDI2 (phenyl-methane-based PDI dimer) and a 3D configuration tetramer PM-PDI4 (phenyl-methane-based PDI tetramer), in different solvents using ultrafast femtosecond transient absorption (fs-TA) spectroscopy and quantum chemical calculations. The quantum chemical calculations and steady-state spectra show that the two PDI derivatives undergo conformational changes upon excitation, leading to their emission states that have the characteristics of partial charge-transfer (CT) exciton in all solvents. Based on the evolution of the fs-TA data, it is observed that the evolution from the CT state to SB-CS state is disfavored in a weak polar solvent, whereas clear SB-CS spectroscopic signatures of cationic and anionic PDI are observed in polar solvents. Faster CS and slower CR processes of PM-PDI4 are observed in comparison to those of PM-PDI2. The crowded space in the 3D structure shortens the distance between the branches, leading to a stronger electronic coupling at the lowest excited state and a larger negative Gibbs free energy change of PM-PDI4 relative to that of PM-PDI2, which benefits the charge separation among PDI units in PM-PDI4. Besides, the 3D structure of PM-PDI4 also restricts rotation to a surface crossing region between the excited state and ground state, thus inhibiting nonradiative CR process and increasing the CS state lifetime. Our results suggest that the kinetics of CS and CR processes are strongly related to the molecular geometric structure, and the excited-state symmetry breaking in the 3D structure acceptor has superior photogenerated charge and photovoltaic properties from the perspective of ultrafast dynamics.
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Affiliation(s)
- Jie Kong
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Wei Zhang
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Gang Li
- College of Chemistry, Chemical Engineering and Materials Science, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Institute of Materials and Clean Energy, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan 250014, P.R. China
| | - Dayujia Huo
- College of Chemistry, Beijing Normal University, Beijing 100875, P.R. China
| | - Yuanyuan Guo
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Xinmiao Niu
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Yan Wan
- College of Chemistry, Beijing Normal University, Beijing 100875, P.R. China
| | - Bo Tang
- College of Chemistry, Chemical Engineering and Materials Science, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Institute of Materials and Clean Energy, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan 250014, P.R. China
| | - Andong Xia
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Sciences, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876, People's Republic of China
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Powers-Riggs NE, Zuo X, Young RM, Wasielewski MR. Solvent independent symmetry-breaking charge separation in terrylenediimide guanine-quadruplex nanoparticles. J Chem Phys 2020; 153:204302. [DOI: 10.1063/5.0027471] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Affiliation(s)
- Natalia E. Powers-Riggs
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, USA
| | - Xiaobing Zuo
- X-ray Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Ryan M. Young
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, USA
| | - Michael R. Wasielewski
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, USA
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Woon KL, Mustapa SAS, Mohd Jamel NS, Lee VS, Zakaria MZ, Ariffin A. Effect of Bulky Functional Groups on Donor and Acceptor Interactions and their Photoluminescence Properties. Chemphyschem 2020; 21:2620-2626. [PMID: 32940952 DOI: 10.1002/cphc.202000612] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 09/07/2020] [Indexed: 12/15/2022]
Abstract
Material designs that use donor and acceptor units are often found in organic optoelectronic devices. Molecular level insight into the interactions between donors and acceptors are crucial for understanding how such interactions can modify the optical properties of the organic optoelectronic materials. In this paper, tris(4-(tert-butyl)phenyl)amine (pTPA) was synthesized as a donor in order to compare with unmodified triphenylamine (TPA) in a donor-acceptor system by having 2,4,6-triphenyl-1,3,5-triazine (TRZ) as an acceptor. Dimerization of donors and acceptors occurred in solvent when the concentration of solute is high. At 0 K, using a polarizable continuum model, the nitrogen atom of TPA is found to stack on top of the center of triazine of TRZ, whereas such alignment is offset in pTPA and TRZ. We attributed such alignment in TPA-TRZ as the result of attractive interactions between partial localization of 2pz electrons at the nitrogen atom of TPA and the π deficiency of triazine in TPA-TRZ. By taking into account random motions of the solvent effect at 300 K in quantum molecular dynamics and classical molecular dynamics simulations to interpret the marked difference in emission spectra between TPA-TRZ and pTPA-TRZ, it was revealed that the attractive interaction between pTPA and TRZ in toluene is weaker than TPA and TRZ. Because of the weaker attractive interaction between pTPA and TRZ in toluene, the dimers adopted numerous ground state conformations resulting in broad emission bands superimposed with multiple small Gaussian peaks. This is in contrast to TPA-TRZ which has only one dominant dimer conformation. This study demonstrates that the strength of intermolecular interactions between donors and acceptors should be taken into consideration in designing supramolecular structures.
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Affiliation(s)
- Kai Lin Woon
- Low Dimensional Material Research Centre, Department of Physics, University Malaya, Kuala Lumpur, Malaysia
| | | | - Nor Shafiq Mohd Jamel
- Department of Chemistry, Faculty of Science, University Malaya, Kuala Lumpur, Malaysia
| | | | | | - Azhar Ariffin
- Department of Chemistry, Faculty of Science, University Malaya, Kuala Lumpur, Malaysia
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Young RM, Wasielewski MR. Mixed Electronic States in Molecular Dimers: Connecting Singlet Fission, Excimer Formation, and Symmetry-Breaking Charge Transfer. Acc Chem Res 2020; 53:1957-1968. [PMID: 32786248 DOI: 10.1021/acs.accounts.0c00397] [Citation(s) in RCA: 118] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
ConspectusChromophore aggregates are capable of a wide variety of excited-state dynamics that are potentially of great use in optoelectronic devices based on organic molecules. For example, singlet fission, the process by which a singlet exciton is down converted into two triplet excitons, holds promise for extending the efficiency of solar cells, while other processes, such as excimer formation, are commonly regarded as parasitic pathways or traps. Other processes, such as symmetry-breaking charge transfer, where the excited dimer charge separates into a radical ion pair, can be both a trap and potentially useful in devices, depending on the context. Thus, an understanding of the precise mechanisms of each of these processes is vital to designing tailor-made organic chromophores for molecular optoelectronics.These excited-state phenomena have each been well-studied in recent years and show tantalizing connections as the molecular systems and environments are subtly changed. These seemingly disparate phenomena can be described within the same unifying framework, where each case can be represented as one point in continuum of mixed states. The coherent mixed state is observed experimentally, and it collapses to each of the limiting cases under well-defined conditions. This framework is especially useful in demonstrating the connections between these different states so that we can determine the factors that control their evolution and may ultimately guide the state mixtures to the product state of choice. The emerging picture shows that tuning the electronic coupling through proper arrangement of the chromophores must accompany environmental tuning of the chromophore energies to produce a fully mixed state. Changes in either of these quantities leads to evolution of the admixture and ultimately collapsing the superposition onto a given state, producing one of the photophysical pathways discussed above.In our laboratory, we are utilizing covalent dimers to precisely arrange the chromophores in rigid, well-defined geometries to systematically study the factors that determine the degree of state mixing and its fate. We interrogate these dynamics with transient absorption spectroscopy from the UV continuously into the mid-infrared, along with time-resolved Raman and emission and magnetic resonance spectroscopies to build a complete and detailed molecular level picture of the dynamics of these dimers. The knowledge gained from dimer studies can also be applied to the understanding the dynamics in extended molecular solids. The insight afforded by these studies will help guide the creation of new designer chromophores with control over the fate of the excited state.
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Affiliation(s)
- Ryan M. Young
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Michael R. Wasielewski
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
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Zhang Z, Sun G, Chen W, Su J, Tian H. The endeavor of vibration-induced emission (VIE) for dynamic emissions. Chem Sci 2020; 11:7525-7537. [PMID: 32874525 PMCID: PMC7448294 DOI: 10.1039/d0sc01591a] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 05/05/2020] [Indexed: 12/12/2022] Open
Abstract
Organic chromophores with large Stokes shifts and dual emissions are fascinating because of their fundamental and applied interest. Vibration-induced emission (VIE) refers to a tunable multiple fluorescence exhibited by saddle-shaped N,N'-disubstituted-dihydribenzo[a,c]phenazines (DHPs), which involves photo-induced configuration vibrations from bent to planar form along the N-N axis. VIE-active molecules show intrinsic long-wavelength emissions in the unconstrained state (planar state) but bright short-wavelength emissions in the constrained state (bent state). The emission response for VIE-active luminogens is highly sensitive to steric hindrance encountered during the planarization process such that a tiny structural variation can induce an evident change in fluorescence. This can often be achieved by tuning the intensity ratio of short- and long-wavelength bands. In some special cases, the alterations in the emission wavelength of VIE fluorophores can be achieved step by step by harnessing the degree of bending angle motion in the excited state. In this perspective, we summarize the latest progress in the field of VIE research. New bent heterocyclic structures, as novel types of VIE molecules, are being developed, and the general features of the chemical structures are also being proposed. Technologically, novel emission color-tuning approaches and VIE-based probes for visualizing biological activity are presented to demonstrate how the dynamic VIE effect can be exploited for cutting-edge applications.
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Affiliation(s)
- Zhiyun Zhang
- Key Laboratory for Advanced Materials , Feringa Nobel Prize Scientist Joint Research Center , Institute of Fine Chemicals , School of Chemistry and Molecular Engineering , East China University of Science & Technology , 130 Meilong Road , Shanghai , 200237 , China .
| | - Guangchen Sun
- Key Laboratory for Advanced Materials , Feringa Nobel Prize Scientist Joint Research Center , Institute of Fine Chemicals , School of Chemistry and Molecular Engineering , East China University of Science & Technology , 130 Meilong Road , Shanghai , 200237 , China .
| | - Wei Chen
- Key Laboratory for Advanced Materials , Feringa Nobel Prize Scientist Joint Research Center , Institute of Fine Chemicals , School of Chemistry and Molecular Engineering , East China University of Science & Technology , 130 Meilong Road , Shanghai , 200237 , China .
| | - Jianhua Su
- Key Laboratory for Advanced Materials , Feringa Nobel Prize Scientist Joint Research Center , Institute of Fine Chemicals , School of Chemistry and Molecular Engineering , East China University of Science & Technology , 130 Meilong Road , Shanghai , 200237 , China .
| | - He Tian
- Key Laboratory for Advanced Materials , Feringa Nobel Prize Scientist Joint Research Center , Institute of Fine Chemicals , School of Chemistry and Molecular Engineering , East China University of Science & Technology , 130 Meilong Road , Shanghai , 200237 , China .
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42
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Cacioppo M, Scharl T, Đorđević L, Cadranel A, Arcudi F, Guldi DM, Prato M. Symmetry-Breaking Charge-Transfer Chromophore Interactions Supported by Carbon Nanodots. Angew Chem Int Ed Engl 2020; 59:12779-12784. [PMID: 32282973 PMCID: PMC7496469 DOI: 10.1002/anie.202004638] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Indexed: 11/10/2022]
Abstract
Carbon dots (CDs) and their derivatives are useful platforms for studying electron-donor/acceptor interactions and dynamics therein. Herein, we couple amorphous CDs with phthalocyanines (Pcs) that act as electron donors with a large extended π-surface and intense absorption across the visible range of the solar spectrum. Investigations of the intercomponent interactions by means of steady-state and pump-probe transient absorption spectroscopy reveal symmetry-breaking charge transfer/separation and recombination dynamics within pairs of phthalocyanines. The CDs facilitate the electronic interactions between the phthalocyanines. Thus, our findings suggest that CDs could be used to support electronic couplings in multichromophoric systems and further increase their applicability in organic electronics, photonics, and artificial photosynthesis.
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Affiliation(s)
- Michele Cacioppo
- Department of Chemical and Pharmaceutical SciencesUniversity of Trieste, and INSTM, unit of TriesteVia Licio Giorgieri 134127TriesteItaly
| | - Tobias Scharl
- Department of Chemistry and Pharmacy, Interdisciplinary Center for Molecular MaterialsFriedrich-Alexander Universität Erlangen-NürnbergEgerlandstrasse 391058ErlangenGermany
| | - Luka Đorđević
- Department of Chemical and Pharmaceutical SciencesUniversity of Trieste, and INSTM, unit of TriesteVia Licio Giorgieri 134127TriesteItaly
- Present address: Department of ChemistryNorthwestern University2145 Sheridan RoadEvanstonIL60208USA
- Present address: Simpson Querrey InstituteNorthwestern University303 E. SuperiorChicagoIL60611USA
| | - Alejandro Cadranel
- Department of Chemistry and Pharmacy, Interdisciplinary Center for Molecular MaterialsFriedrich-Alexander Universität Erlangen-NürnbergEgerlandstrasse 391058ErlangenGermany
- Universidad de Buenos AiresFacultad de Ciencias Exactas y NaturalesDepartamento de Química Inorgánica, Analítica y Química FísicaPabellón 2, Ciudad UniversitariaC1428EHABuenos AiresArgentina
- CONICET—Universidad de Buenos AiresInstituto de Química-Física de Materiales, Medio Ambiente y Energía (INQUIMAE)Pabellón 2, Ciudad UniversitariaC1428EHA BuenosAiresArgentina
| | - Francesca Arcudi
- Department of Chemical and Pharmaceutical SciencesUniversity of Trieste, and INSTM, unit of TriesteVia Licio Giorgieri 134127TriesteItaly
- Present address: Department of ChemistryNorthwestern University2145 Sheridan RoadEvanstonIL60208USA
| | - Dirk M. Guldi
- Department of Chemistry and Pharmacy, Interdisciplinary Center for Molecular MaterialsFriedrich-Alexander Universität Erlangen-NürnbergEgerlandstrasse 391058ErlangenGermany
| | - Maurizio Prato
- Department of Chemical and Pharmaceutical SciencesUniversity of Trieste, and INSTM, unit of TriesteVia Licio Giorgieri 134127TriesteItaly
- Center for Cooperative Research in Biomaterials (CIC biomaGUNE)Basque Research and Technology Alliance (BRTA)Paseo de Miramon 18220014Donostia San SebastiánSpain
- Basque Foundation for ScienceIkerbasqueBilbao48013Spain
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43
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Gutiérrez L, Mondal SS, Bucci A, Kandoth N, Escudero-Adán EC, Shafir A, Lloret-Fillol J. Crystal-to-Crystal Synthesis of Photocatalytic Metal-Organic Frameworks for Visible-Light Reductive Coupling and Mechanistic Investigations. CHEMSUSCHEM 2020; 13:3418-3428. [PMID: 32351031 DOI: 10.1002/cssc.202000465] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 04/03/2020] [Indexed: 06/11/2023]
Abstract
Postmodification of reticular materials with well-defined catalysts is an appealing approach to produce new catalytic functional materials with improved stability and recyclability, but also to study catalysis in confined spaces. A promising strategy to this end is the postfunctionalization of crystalline and robust metal-organic frameworks (MOFs) to exploit the potential of crystal-to-crystal transformations for further characterization of the catalysts. In this regard, two new photocatalytic materials, MOF-520-PC1 and MOF-520-PC2, are straightforwardly obtained by the postfunctionalization of MOF-520 with perylene-3-carboxylic acid (PC1) and perylene-3-butyric acid (PC2). The single crystal-to-crystal transformation yielded the X-ray diffraction structure of catalytic MOF-520-PC2. The well-defined disposition of the perylenes inside the MOF served as suitable model systems to gain insights into the photophysical properties and mechanism by combining steady-state, time-resolved, and transient absorption spectroscopy. The resulting materials are active organophotoredox catalysts in the reductive dimerization of aromatic aldehydes, benzophenones, and imines under mild reaction conditions. Moreover, MOF-520-PC2 can be applied for synthesizing gram-scale quantities of products in continuous-flow conditions under steady-state light irradiation. This work provides an alternative approach for the construction of well-defined, metal-free, MOF-based catalysts.
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Affiliation(s)
- Luis Gutiérrez
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Avinguda Païos Catalans 16, 43007, Tarragona, Spain
| | - Suvendu Sekhar Mondal
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Avinguda Païos Catalans 16, 43007, Tarragona, Spain
| | - Alberto Bucci
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Avinguda Païos Catalans 16, 43007, Tarragona, Spain
| | - Noufal Kandoth
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Avinguda Païos Catalans 16, 43007, Tarragona, Spain
| | - Eduardo C Escudero-Adán
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Avinguda Païos Catalans 16, 43007, Tarragona, Spain
| | - Alexandr Shafir
- Institute of Advanced Chemistry of Catalonia (IQAC-CSIC), c/Jordi Girona 18-26, 08034, Barcelona, Spain
| | - Julio Lloret-Fillol
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Avinguda Païos Catalans 16, 43007, Tarragona, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), Passeig Lluïs Companys, 23, 08010, Barcelona, Spain
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Szakács Z, Tasior M, Gryko DT, Vauthey E. Change of Quadrupole Moment upon Excitation and Symmetry Breaking in Multibranched Donor-Acceptor Dyes. Chemphyschem 2020; 21:1718-1730. [PMID: 32415748 DOI: 10.1002/cphc.202000253] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 05/11/2020] [Indexed: 02/04/2023]
Abstract
Upon photoexcitation, a majority of quadrupolar dyes, developed for large two-photon absorption, undergo excited-state symmetry breaking (ES-SB) and behave as dipolar molecules. We investigate how the change of quadrupole moment upon S1 ←S0 excitation, ΔQ, influences the propensity of a dye to undergo ES-SB using a series of molecules with a A-π-D-π-A motif where D is the exceptionally electron-rich pyrrolo[3,2-b]pyrrole and A are accepting groups. Tuning of ΔQ is achieved by appending a secondary acceptor group, A', on both sides of the D core and ES-SB is monitored using a combination of time-resolved IR and broadband fluorescence spectroscopy. The results reveal a clear correlation between ΔQ and the tendency to undergo ES-SB. When A is a stronger acceptor than A', ES-SB occurs already in non-dipolar but quadrupolar solvents. When A and A' are identical, ES-SB is only partial even in highly dipolar solvents. When A is a weaker acceptor than A', the orientation of ΔQ changes, ES-SB is observed in dipolar solvents only and involves major redistribution of the excitation over the D-π-A and D-A' branches of the dye.
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Affiliation(s)
- Zoltán Szakács
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, 1211, Genève 4, Switzerland
| | - Mariusz Tasior
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
| | - Daniel T Gryko
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
| | - Eric Vauthey
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, 1211, Genève 4, Switzerland
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45
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Cacioppo M, Scharl T, Đorđević L, Cadranel A, Arcudi F, Guldi DM, Prato M. Symmetry‐Breaking Charge‐Transfer Chromophore Interactions Supported by Carbon Nanodots. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202004638] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Michele Cacioppo
- Department of Chemical and Pharmaceutical Sciences University of Trieste, and INSTM, unit of Trieste Via Licio Giorgieri 1 34127 Trieste Italy
| | - Tobias Scharl
- Department of Chemistry and Pharmacy, Interdisciplinary Center for Molecular Materials Friedrich-Alexander Universität Erlangen-Nürnberg Egerlandstrasse 3 91058 Erlangen Germany
| | - Luka Đorđević
- Department of Chemical and Pharmaceutical Sciences University of Trieste, and INSTM, unit of Trieste Via Licio Giorgieri 1 34127 Trieste Italy
- Present address: Department of Chemistry Northwestern University 2145 Sheridan Road Evanston IL 60208 USA
- Present address: Simpson Querrey Institute Northwestern University 303 E. Superior Chicago IL 60611 USA
| | - Alejandro Cadranel
- Department of Chemistry and Pharmacy, Interdisciplinary Center for Molecular Materials Friedrich-Alexander Universität Erlangen-Nürnberg Egerlandstrasse 3 91058 Erlangen Germany
- Universidad de Buenos Aires Facultad de Ciencias Exactas y Naturales Departamento de Química Inorgánica, Analítica y Química Física Pabellón 2, Ciudad Universitaria C1428EHA Buenos Aires Argentina
- CONICET— Universidad de Buenos Aires Instituto de Química-Física de Materiales, Medio Ambiente y Energía (INQUIMAE) Pabellón 2, Ciudad Universitaria C1428EHA Buenos Aires Argentina
| | - Francesca Arcudi
- Department of Chemical and Pharmaceutical Sciences University of Trieste, and INSTM, unit of Trieste Via Licio Giorgieri 1 34127 Trieste Italy
- Present address: Department of Chemistry Northwestern University 2145 Sheridan Road Evanston IL 60208 USA
| | - Dirk M. Guldi
- Department of Chemistry and Pharmacy, Interdisciplinary Center for Molecular Materials Friedrich-Alexander Universität Erlangen-Nürnberg Egerlandstrasse 3 91058 Erlangen Germany
| | - Maurizio Prato
- Department of Chemical and Pharmaceutical Sciences University of Trieste, and INSTM, unit of Trieste Via Licio Giorgieri 1 34127 Trieste Italy
- Center for Cooperative Research in Biomaterials (CIC biomaGUNE) Basque Research and Technology Alliance (BRTA) Paseo de Miramon 182 20014 Donostia San Sebastián Spain
- Basque Foundation for Science Ikerbasque Bilbao 48013 Spain
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46
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Eng J, Penfold TJ. Understanding and Designing Thermally Activated Delayed Fluorescence Emitters: Beyond the Energy Gap Approximation. CHEM REC 2020; 20:831-856. [PMID: 32267093 DOI: 10.1002/tcr.202000013] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 03/13/2020] [Indexed: 11/08/2022]
Abstract
In this article recent progress in the development of molecules exhibiting Thermally Activated Delayed Fluorescence (TADF) is discussed with a particular focus upon their application as emitters in highly efficient organic light emitting diodes (OLEDs). The key aspects controlling the desirable functional properties, e. g. fast intersystem crossing, high radiative rate and unity quantum yield, are introduced with a particular focus upon the competition between the key requirements needed to achieve high performance OLEDs. The design rules required for organic and metal organic materials are discussed, and the correlation between them outlined. Recent progress towards understanding the influence of the interaction between a molecule and its environment are explained as is the role of the mechanism for excited state formation in OLEDs. Finally, all of these aspects are combined to discuss the ability to implement high level design rules for achieving higher quality materials for commercial applications. This article highlights the significant progress that has been made in recent years, but also outlines the significant challenges which persist to achieve a full understanding of the TADF mechanism and improve the stability and performance of these materials.
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Affiliation(s)
- Julien Eng
- Chemistry, School of Natural and Environmental Sciences, Newcastle University, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - Thomas J Penfold
- Chemistry, School of Natural and Environmental Sciences, Newcastle University, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
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47
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Homberg A, Lacour J. From reactive carbenes to chiral polyether macrocycles in two steps - synthesis and applications made easy? Chem Sci 2020; 11:6362-6369. [PMID: 34094103 PMCID: PMC8152409 DOI: 10.1039/d0sc01011a] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 03/11/2020] [Indexed: 12/26/2022] Open
Abstract
Chiral polyether macrocycles are versatile molecules. For their preparation, original two-step procedures were recently developed and present the advantages of high concentration conditions and simple starting reagents (stable diazo reagents, small cyclic ethers, aliphatic or aromatic amines). Enantiopure materials are readily afforded by CSP-HPLC on a semi-preparative scale. Flexibility and adaptability in the macrocyclic design are provided by a large selection of amines to choose from while the ring size and chemical nature are controlled by the choice of 5 to 7-membered cyclic ether precursors. Such macrocycles have already been used as asymmetric catalysts, mono and ditopic receptors, fluorescent sensors and probes, and chiroptical reversible switches.
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Affiliation(s)
- Alexandre Homberg
- Department of Organic Chemistry, University of Geneva Quai Ernest Ansermet 30 1211 Geneva 4 Switzerland
| | - Jérôme Lacour
- Department of Organic Chemistry, University of Geneva Quai Ernest Ansermet 30 1211 Geneva 4 Switzerland
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Brun E, Zhang KF, Guénée L, Lacour J. Photo-induced thiol-ene reactions for late-stage functionalization of unsaturated polyether macrocycles: regio and diastereoselective access to macrocyclic dithiol derivatives. Org Biomol Chem 2020; 18:250-254. [PMID: 31808765 DOI: 10.1039/c9ob02375e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Double hydrothiolation of bis enol ether macrocycles was achieved under photo-mediated conditions. The thiol-ene reactions afford a fully regioselective anti-Markovnikov post-functionalization. Thanks to the use of ethanedithiol as reagent, moderate to excellent diastereoselectivity was accomplished leading to macrocycles containing four defined stereocenters in only three steps from 1,4-dioxane, tetrahydrofuran (THF) or tetrahydropyran (THP).
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Affiliation(s)
- Elodie Brun
- Department of Organic Chemistry, University of Geneva, Quai Ernest Ansermet 30, 1211 Geneva 4, Switzerland.
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49
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Dhbaibi K, Favereau L, Srebro-Hooper M, Quinton C, Vanthuyne N, Arrico L, Roisnel T, Jamoussi B, Poriel C, Cabanetos C, Autschbach J, Crassous J. Modulation of circularly polarized luminescence through excited-state symmetry breaking and interbranched exciton coupling in helical push-pull organic systems. Chem Sci 2020; 11:567-576. [PMID: 32206274 PMCID: PMC7069512 DOI: 10.1039/c9sc05231c] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 11/19/2019] [Indexed: 11/21/2022] Open
Abstract
π-Helical push-pull dyes were prepared and their (chir)optical properties were investigated both experimentally and computationally. Specific fluorescent behaviour of bis-substituted system was observed with unprecedented solvent effect on the intensity of circularly polarized luminescence (CPL, dissymmetry factor decreasing from 10-2 to 10-3 with an increase in solvent polarity) that was linked to a change in symmetry of chiral excited state and suppression of interbranched exciton coupling. The results highlight the potential of CPL spectroscopy to study and provide a deeper understanding of electronic photophysical processes in chiral π-conjugated molecules.
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Affiliation(s)
- Kais Dhbaibi
- Univ Rennes , CNRS , ISCR - UMR 6226 , ScanMAT - UMS 2001 , F-35000 Rennes , France . ;
- University of Gabès , Faculty of Science of Gabès , Zrig , 6072 Gabès , Tunisia
| | - Ludovic Favereau
- Univ Rennes , CNRS , ISCR - UMR 6226 , ScanMAT - UMS 2001 , F-35000 Rennes , France . ;
| | - Monika Srebro-Hooper
- Faculty of Chemistry , Jagiellonian University , Gronostajowa 2 , 30-387 Krakow , Poland .
| | - Cassandre Quinton
- Univ Rennes , CNRS , ISCR - UMR 6226 , ScanMAT - UMS 2001 , F-35000 Rennes , France . ;
| | - Nicolas Vanthuyne
- Aix Marseille University , CNRS , Centrale Marseille , iSm2 , Marseille , France
| | - Lorenzo Arrico
- Dipartimento di Chimica e Chimica Industriale , University of Pisa , via Moruzzi 13 , 56124 , Pisa , Italy
| | - Thierry Roisnel
- Univ Rennes , CNRS , ISCR - UMR 6226 , ScanMAT - UMS 2001 , F-35000 Rennes , France . ;
| | - Bassem Jamoussi
- Department of Environmental Sciences , Faculty of Meteorology, Environment and Arid Land Agriculture , King Abdulaziz University , 21589 Jeddah , Saudi Arabia
| | - Cyril Poriel
- Univ Rennes , CNRS , ISCR - UMR 6226 , ScanMAT - UMS 2001 , F-35000 Rennes , France . ;
| | - Clément Cabanetos
- MOLTECH-Anjou , CNRS UMR 6200 , University of Angers , 2 Bd Lavoisier , 49045 Angers , France
| | - Jochen Autschbach
- Department of Chemistry , University at Buffalo , State University of New York , Buffalo , NY 14260 , USA
| | - Jeanne Crassous
- Univ Rennes , CNRS , ISCR - UMR 6226 , ScanMAT - UMS 2001 , F-35000 Rennes , France . ;
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