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Tiwari V, Li X, Li Z, Jacobs IE, Duan HG, Sirringhaus H, Miller RJD, Jha A. Multitype Electronic Interactions in Precursor Solutions of Molecular Doped P3HT Polymer. J Phys Chem B 2024; 128:3249-3257. [PMID: 38507573 DOI: 10.1021/acs.jpcb.4c00584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
Spin-casting of molecularly doped polymer solution mixtures is one of the commonly used methods to obtain conductive organic semiconductor films. In spin-casted films, electronic interaction between the dopant and polymer is one of the crucial factors that dictates the doping efficiency. Here, we investigate excitonic couplings using ultrafast two-dimensional electronic spectroscopy to examine the different types of electronic interactions in ion pairs of the prototype F4TCNQ-doped P3HT polymer system in a precursor solution mixture for spin-casting. Off-diagonal peaks in the 2D spectra clearly establish the excitonic coupling between P3HT+ and F4TCNQ- ions in solution. The observed excitonic coupling is the direct manifestation of a Coulombic interaction between the ion pair. The excited-state lifetime of F4TCNQ- in ion pairs shows biexponential decay at 30 and 200 fs, which hints toward the presence of a heterogeneous population with different interaction strengths. To examine the nature of these different types of interactions in solution mixtures, we study the system using molecular dynamics simulations on a fully solvated model employing the generalized Amber force field. We retrieve three dominant interaction modes of F4TCNQ anions with P3HT: side chain, π-stack, and slipped stack. To quantify these interactions, we complement our studies with electronic structure calculations, which reveal the excitonic coupling strengths of ∼ 75 cm-1 for side chain, ∼ 150 cm-1 for π-π-stack, and ∼69 cm-1 for slipped stack. These various interaction modes provide information about the key geometries of the seed structures in precursor solution mixtures, which may determine the final structures in spin-casted films. The insights gained from our study may guide new strategies to control and ultimately tune Coulomb interactions in polymer-dopant solutions.
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Affiliation(s)
- Vandana Tiwari
- European XFEL GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Xin Li
- Division of Theoretical Chemistry & Biology, KTH Royal Institute of Technology, SE-10691 Stockholm, Sweden
| | - Zheng Li
- State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
- Yangtze Delta Institute of Optoelectronics, Peking University Nantong, Jiangsu 226010, China
| | - Ian E Jacobs
- Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, U.K
| | - Hong-Guang Duan
- Department of Physics, School of Physical Science & Technology, Ningbo University, Ningbo 315211, P. R. China
| | - Henning Sirringhaus
- Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, U.K
| | - R J Dwayne Miller
- Departments of Chemistry & Physics, University of Toronto, Toronto M5S 3H6, Canada
| | - Ajay Jha
- Rosalind Franklin Institute, Harwell, Oxfordshire OX11 0QX, U.K
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, U.K
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2
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Hou L, Jing X, Huang H, Duan C. Merging Charge Transfer into Metal-Organic Frameworks to Achieve High Reduction Potentials via Multiphoton Excitation. ACS APPLIED MATERIALS & INTERFACES 2022; 14:15307-15316. [PMID: 35344330 DOI: 10.1021/acsami.2c01595] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Utilization of multiphotons to achieve high reduction potentials is a highly demanding but still challenging task for reductive cleavage of inert bonds. Herein, we report a new charge transfer approach that simultaneously excites the electron-rich dye and the radical anionic of the electron-deficient one for photocatalytic activation of aryl chlorides with high reduction potentials (Ered ≈ -1.9 to -2.9 V). Interactions between the tetraphenylbenzene-1,4,-diamine dyes in the large pores of metal-organic frameworks and the adsorbed 9,10-dicyanoanthracene partly endows charge transfer in the ground state. The first photoexcitation led to the formation charge separation pairs containing both radical cation and anion for second photon excitation. The possibility of modifying each absorption band of the two dyes independently innovated the resultant aryl radicals applied in various useful transformations, expanding multiphoton manifolds on both the dye scopes and reaction versions. A comparison of the catalytic performance between different structural patterns of metal-organic frameworks with the same ligand demonstrated that the incorporating of the organic dyes within the pores of the frameworks was essential to form charge-transfer species and accelerate the interesting chemical conversion.
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Affiliation(s)
- Leixin Hou
- State Key Laboratory of Fine Chemicals, Zhang Dayu College of Chemistry, Dalian University of Technology, Dalian 116024, P.R. China
| | - Xu Jing
- State Key Laboratory of Fine Chemicals, Zhang Dayu College of Chemistry, Dalian University of Technology, Dalian 116024, P.R. China
| | - Huilin Huang
- State Key Laboratory of Fine Chemicals, Zhang Dayu College of Chemistry, Dalian University of Technology, Dalian 116024, P.R. China
| | - Chunying Duan
- State Key Laboratory of Fine Chemicals, Zhang Dayu College of Chemistry, Dalian University of Technology, Dalian 116024, P.R. China
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Pshenichnyuk SA, Modelli A, Asfandiarov NL, Rakhmeyev RG, Safronov AM, Tayupov MM, Komolov AS. Microsecond dynamics of molecular negative ions formed by low-energy electron attachment to fluorinated tetracyanoquinodimethane. J Chem Phys 2021; 155:184301. [PMID: 34773960 DOI: 10.1063/5.0072264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Low-energy (0-15 eV) electron interactions with gas-phase 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ) molecules are studied under single collision conditions using dissociative electron attachment spectroscopy. The experimental findings are supported by density functional theory calculations of the virtual orbital energies and energetics of the dissociative decays. Long-lived molecular negative ions F4-TCNQ- are detected in a wide electron energy range (0-3 eV) with electron detachment times in the range of milliseconds. Although plenty of decay channels are observed, their intensities are found to be very small (two to four orders of magnitude relative to the F4-TCNQ- signal). These findings prove that the structure of this strong electron-accepting molecule bearing an excess electron is robust in its electronic ground state, even when highly (up to 6 eV) vibrationally excited. As many as nine metastable fragment anions formed slowly (in the 16-23 µs range) are found in the negative ion mass spectrum of F4-TCNQ, as never observed before in compounds possessing high electron-accepting ability. The present results shed some light on microsecond dynamics of isolated F4-TCNQ molecules under conditions of excess negative charge, which are important for understanding the functionality of nanoscale devices containing this molecule as a structural element.
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Affiliation(s)
- Stanislav A Pshenichnyuk
- Institute of Molecule and Crystal Physics, Ufa Federal Research Centre, Russian Academy of Sciences, Prospekt Oktyabrya 151, 450075 Ufa, Russia
| | - Alberto Modelli
- Università di Bologna, Centro Interdipartimentale di Ricerca in Scienze Ambientali, via S. Alberto 163, 48123 Ravenna, Italy
| | - Nail L Asfandiarov
- Institute of Molecule and Crystal Physics, Ufa Federal Research Centre, Russian Academy of Sciences, Prospekt Oktyabrya 151, 450075 Ufa, Russia
| | - Rustam G Rakhmeyev
- Institute of Molecule and Crystal Physics, Ufa Federal Research Centre, Russian Academy of Sciences, Prospekt Oktyabrya 151, 450075 Ufa, Russia
| | - Aleksey M Safronov
- Institute of Molecule and Crystal Physics, Ufa Federal Research Centre, Russian Academy of Sciences, Prospekt Oktyabrya 151, 450075 Ufa, Russia
| | - Mansaf M Tayupov
- Institute of Molecule and Crystal Physics, Ufa Federal Research Centre, Russian Academy of Sciences, Prospekt Oktyabrya 151, 450075 Ufa, Russia
| | - Alexei S Komolov
- St. Petersburg State University, Universitetskaya nab. 7/9, 199034 St. Petersburg, Russia
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4
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Heat Enhanced Follicular Delivery of Isotretinoin to the Skin. Pharm Res 2019; 36:124. [DOI: 10.1007/s11095-019-2659-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 06/11/2019] [Indexed: 02/07/2023]
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5
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Jha A, Duan HG, Tiwari V, Thorwart M, Miller RJD. Origin of poor doping efficiency in solution processed organic semiconductors. Chem Sci 2018; 9:4468-4476. [PMID: 29896388 PMCID: PMC5956981 DOI: 10.1039/c8sc00758f] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 04/07/2018] [Indexed: 12/26/2022] Open
Abstract
Doping is an extremely important process where intentional insertion of impurities in semiconductors controls their electronic properties. In organic semiconductors, one of the convenient, but inefficient, ways of doping is the spin casting of a precursor mixture of components in solution, followed by solvent evaporation. Active control over this process holds the key to significant improvements over current poor doping efficiencies. Yet, an optimized control can only come from a detailed understanding of electronic interactions responsible for the low doping efficiencies. Here, we use two-dimensional nonlinear optical spectroscopy to examine these interactions in the course of the doping process by probing the solution mixture of doped organic semiconductors. A dopant accepts an electron from the semiconductor and the two ions form a duplex of interacting charges known as ion-pair complexes. Well-resolved off-diagonal peaks in the two-dimensional spectra clearly demonstrate the electronic connectivity among the ions in solution. This electronic interaction represents a well resolved electrostatically bound state, as opposed to a random distribution of ions. We developed a theoretical model to recover the experimental data, which reveals an unexpectedly strong electronic coupling of ∼250 cm-1 with an intermolecular distance of ∼4.5 Å between ions in solution, which is approximately the expected distance in processed films. The fact that this relationship persists from solution to the processed film gives direct evidence that Coulomb interactions are retained from the precursor solution to the processed films. This memory effect renders the charge carriers equally bound also in the film and, hence, results in poor doping efficiencies. This new insight will help pave the way towards rational tailoring of the electronic interactions to improve doping efficiencies in processed organic semiconductor thin films.
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Affiliation(s)
- Ajay Jha
- Max Planck Institute for the Structure and Dynamics of Matter , Luruper Chaussee 149 , 22761 , Hamburg , Germany .
| | - Hong-Guang Duan
- Max Planck Institute for the Structure and Dynamics of Matter , Luruper Chaussee 149 , 22761 , Hamburg , Germany . .,I. Institut für Theoretische Physik , Universität Hamburg , Jungiusstraße 9 , 20355 Hamburg , Germany.,The Hamburg Center for Ultrafast Imaging , Luruper Chaussee 149 , 22761 Hamburg , Germany
| | - Vandana Tiwari
- Max Planck Institute for the Structure and Dynamics of Matter , Luruper Chaussee 149 , 22761 , Hamburg , Germany . .,Department of Chemistry , University of Hamburg , Martin-Luther-King Platz 6 , 20146 Hamburg , Germany
| | - Michael Thorwart
- I. Institut für Theoretische Physik , Universität Hamburg , Jungiusstraße 9 , 20355 Hamburg , Germany.,The Hamburg Center for Ultrafast Imaging , Luruper Chaussee 149 , 22761 Hamburg , Germany
| | - R J Dwayne Miller
- Max Planck Institute for the Structure and Dynamics of Matter , Luruper Chaussee 149 , 22761 , Hamburg , Germany . .,The Hamburg Center for Ultrafast Imaging , Luruper Chaussee 149 , 22761 Hamburg , Germany.,The Departments of Chemistry and Physics , University of Toronto , 80 St. George Street , Toronto , Canada M5S 3H6
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6
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Bull JN, West CW, Verlet JRR. On the formation of anions: frequency-, angle-, and time-resolved photoelectron imaging of the menadione radical anion. Chem Sci 2015; 6:1578-1589. [PMID: 29560245 PMCID: PMC5811081 DOI: 10.1039/c4sc03491k] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 12/17/2014] [Indexed: 11/24/2022] Open
Abstract
Frequency-, angle-, and time-resolved photoelectron imaging of gas-phase menadione (vitamin K3) radical anions was used to show that quasi-bound resonances of the anion can act as efficient doorway states to produce metastable ground electronic state anions on a sub-picosecond timescale. Several anion resonances have been experimentally observed and identified with the assistance of ab initio calculations, and ground state anion recovery was observed across the first 3 eV above threshold. Time-resolved measurements revealed the mechanism of electronic ground state anion formation, which first involves a cascade of very fast internal conversion processes to a bound electronic state that, in turn, decays by slower internal conversion to the ground state. Autodetachment processes from populated resonances are inefficient compared with electronic relaxation through internal conversion. The mechanistic understanding gained provides insight into the formation of radical anions in biological and astrochemical systems.
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Affiliation(s)
- James N Bull
- Department of Chemistry , Durham University , South Road , DH1 3LE , UK .
| | - Christopher W West
- Department of Chemistry , Durham University , South Road , DH1 3LE , UK .
| | - Jan R R Verlet
- Department of Chemistry , Durham University , South Road , DH1 3LE , UK .
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7
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Bull JN, West CW, Verlet JRR. Internal conversion outcompetes autodetachment from resonances in the deprotonated tetracene anion continuum. Phys Chem Chem Phys 2015; 17:32464-71. [DOI: 10.1039/c5cp05388a] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Resonances in deprotonated tetracene decay predominantly to the anion ground state.
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8
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Fujitsuka M, Ohsaka T, Majima T. Dual electron transfer pathways from the excited C60 radical anion: enhanced reactivities due to the photoexcitation of reaction intermediates. Phys Chem Chem Phys 2015; 17:31030-8. [DOI: 10.1039/c5cp05254h] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The excited C60 radical anion showed enhanced electron transfer.
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Affiliation(s)
- Mamoru Fujitsuka
- The Institute of Scientific and Industrial Research (SANKEN)
- Osaka University
- Ibaraki
- Japan
| | - Tatsuya Ohsaka
- The Institute of Scientific and Industrial Research (SANKEN)
- Osaka University
- Ibaraki
- Japan
| | - Tetsuro Majima
- The Institute of Scientific and Industrial Research (SANKEN)
- Osaka University
- Ibaraki
- Japan
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9
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Chatterley AS, Horke DA, Verlet JRR. Effects of resonant excitation, pulse duration and intensity on photoelectron imaging of a dianion. Phys Chem Chem Phys 2014; 16:489-96. [DOI: 10.1039/c3cp53235f] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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10
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Horke DA, Li Q, Blancafort L, Verlet JRR. Ultrafast above-threshold dynamics of the radical anion of a prototypical quinone electron-acceptor. Nat Chem 2013; 5:711-7. [PMID: 23881504 DOI: 10.1038/nchem.1705] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 06/04/2013] [Indexed: 12/30/2022]
Abstract
Quinones feature prominently as electron acceptors in nature. Their electron-transfer reactions are often highly exergonic, for which Marcus theory predicts reduced electron-transfer rates because of a free-energy barrier that occurs in the inverted region. However, the electron-transfer kinetics that involve quinones can appear barrierless. Here, we consider the intrinsic properties of the para-benzoquinone radical anion, which serves as the prototypical electron-transfer reaction product involving a quinone-based acceptor. Using time-resolved photoelectron spectroscopy and ab initio calculations, we show that excitation at 400 and 480 nm yields excited states that are unbound with respect to electron loss. These excited states are shown to decay on a sub-40 fs timescale through a series of conical intersections with lower-lying excited states, ultimately to form the ground anionic state and avoid autodetachment. From an isolated electron-acceptor perspective, this ultrafast stabilization mechanism accounts for the ability of para-benzoquinone to capture and retain electrons.
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Affiliation(s)
- Daniel A Horke
- Department of Chemistry, University of Durham, Durham DH1 3LE, UK
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11
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Ómarsson B, Ingólfsson O. Stabilization, fragmentation and rearrangement reactions in low-energy electron interaction with tetrafluoro-para-benzoquinone: a combined theoretical and experimental study. Phys Chem Chem Phys 2013; 15:16758-67. [DOI: 10.1039/c3cp52397g] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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12
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Grilj J, Buchgraber P, Vauthey E. Excited-State Dynamics of Wurster’s Salts. J Phys Chem A 2012; 116:7516-22. [DOI: 10.1021/jp3045548] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Jakob Grilj
- Department
of Physical Chemistry and ‡Department of Organic Chemistry, University of Geneva, 30 quai Ernest-Ansermet, CH-1211
Geneva 4
| | - Philipp Buchgraber
- Department
of Physical Chemistry and ‡Department of Organic Chemistry, University of Geneva, 30 quai Ernest-Ansermet, CH-1211
Geneva 4
| | - Eric Vauthey
- Department
of Physical Chemistry and ‡Department of Organic Chemistry, University of Geneva, 30 quai Ernest-Ansermet, CH-1211
Geneva 4
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Wyer JA, Støchkel K, Brøndsted Nielsen S. Collisional electron transfer to photoexcited acceptor radical anions. J Chem Phys 2012; 136:084303. [PMID: 22380038 DOI: 10.1063/1.3682245] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
In this article, we show that photoexcitation of radical anions facilitates electron transfer from sodium atoms in femtosecond encounters. Thus, excitation of 7,7,8,8-tetracyano-p-quinodimethane (TCNQ) and fluorinated TCNQ (TCNQ-F(4)) anions to the second optically active state at 478 nm led to increases in the yields of dianions of about 20% and 10%, respectively. Photoexcitation with a nanosecond-long laser pulse was done a few microseconds before the ions entered the sodium collision cell so that none of the ions would be in any of the initially reached doublet-excited states. We suggest an explanation for the higher electron capture cross section based on the formation of long-lived quartet state anions. Excitation of TCNQ anions within the lowest-energy absorption band, where there are no accessible quartet states, led instead to a lower yield of dianions. There are at least three explanations for the lower dianion yields: (1) Depletion of the monoanion beam due to photodetachment after the absorption of minimum two photons; (2) Formation of short-lived vibrationally excited dianions that decay by electron autodetachment prior to identification; and (3) Lower electron capture cross sections of vibrationally excited monoanions. Similar losses in dianion signal can occur at 478 nm so the actual yield of dianions at this wavelength due to the population of quartet states is therefore greater than that observed. Our methodology devises a more efficient route for the production of molecular dianions, and at the same time it may provide information on long-lived electronic states.
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Affiliation(s)
- Jean Ann Wyer
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
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14
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Horke DA, Verlet JRR. Time-resolved photoelectron imaging of the chloranil radical anion: ultrafast relaxation of electronically excited electron acceptor states. Phys Chem Chem Phys 2011; 13:19546-52. [DOI: 10.1039/c1cp22237f] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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