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Majumder K, Mukherjee S, Panjwani NA, Lee J, Bittl R, Kim W, Patil S, Musser AJ. Controlling Intramolecular Singlet Fission Dynamics via Torsional Modulation of Through-Bond versus Through-Space Couplings. J Am Chem Soc 2023; 145:20883-20896. [PMID: 37705333 DOI: 10.1021/jacs.3c06075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/15/2023]
Abstract
Covalent dimers, particularly pentacenes, are the dominant platform for developing a mechanistic understanding of intramolecular singlet fission (iSF). Numerous studies have demonstrated that a photoexcited singlet state in these structures can rapidly and efficiently undergo exciton multiplication to form a correlated pair of triplets within a single molecule, with potential applications from photovoltaics to quantum information science. One of the most significant barriers limiting such dimers is the fast recombination of the triplet pair, which prevents spatial separation and the formation of long-lived triplet states. There is an ever-growing need to develop general synthetic strategies to control the evolution of triplets following iSF and enhance their lifetime. Here, we rationally tune the dihedral angle and interchromophore separation between pairs of pentacenes in a systematic series of bridging units to facilitate triplet separation. Through a combination of transient optical and spin-resonance techniques, we demonstrate that torsion within the linker provides a simple synthetic handle to tune the fine balance between through-bond and through-space interchromophore couplings that steer iSF. We show that the full iSF pathway from femtosecond to microsecond timescales is tuned through the static coupling set by molecular design and structural fluctuations that can be biased through steric control. Our approach highlights a straightforward design principle to generate paramagnetic spin pair states with higher yields.
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Affiliation(s)
- Kanad Majumder
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - Soham Mukherjee
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Naitik A Panjwani
- Berlin Joint EPR Lab, Fachbereich Physik, Freie Universität, Berlin, Berlin 14195, Berlin, Germany
| | - Jieun Lee
- Department of Chemistry, Yonsei University, Seoul 03722, Republic of Korea
| | - Robert Bittl
- Berlin Joint EPR Lab, Fachbereich Physik, Freie Universität, Berlin, Berlin 14195, Berlin, Germany
| | - Woojae Kim
- Department of Chemistry, Yonsei University, Seoul 03722, Republic of Korea
| | - Satish Patil
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - Andrew J Musser
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
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2
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Tracy DA, Fernandez-Alberti S, Tretiak S, Roitberg AE. Adiabatic Excited-State Molecular Dynamics with an Explicit Solvent: NEXMD-SANDER Implementation. J Chem Theory Comput 2022; 18:5213-5220. [PMID: 36044726 DOI: 10.1021/acs.jctc.2c00561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We present a method to link the Nonadiabatic EXcited-state Molecular Dynamics (NEXMD) package to the SANDER package supplied by AMBERTOOLS to provide excited-state adiabatic quantum mechanics/molecular mechanics (QM/MM) simulations. NEXMD is a computational package particularly developed to perform simulations of the photoexcitation and subsequent nonadiabatic electronic and vibrational energy relaxation in large multichromophoric conjugated molecules involving several coupled electronic excited states. The NEXMD-SANDER exchange has been optimized in order to achieve excited-state adiabatic dynamics simulations of large conjugated materials in a QM/MM environment, such as an explicit solvent. Dynamics of a substituted polyphenylene vinylene oligomer (PPV3-NO2) in vacuum and different explicit solvents has been used as a test case by performing comparative analysis of changes in its optical spectrum, state-dependent conformational changes, and quantum bond orderings. The method has been tested and compared with respect to previous implicit solvent implementations. Also, the impact on the expansion of the QM region by including a variable number of solvent molecules has been analyzed. Altogether, these results encourage future implementations of NEXMD simulations using the same combination of methods.
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Affiliation(s)
- Dustin A Tracy
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | | | - Sergei Tretiak
- Theoretical Division, Center for Nonlinear Studies (CNLS) and Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Adrian E Roitberg
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
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3
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Malone W, Nebgen B, White A, Zhang Y, Song H, Bjorgaard JA, Sifain AE, Rodriguez-Hernandez B, Freixas VM, Fernandez-Alberti S, Roitberg AE, Nelson TR, Tretiak S. NEXMD Software Package for Nonadiabatic Excited State Molecular Dynamics Simulations. J Chem Theory Comput 2020; 16:5771-5783. [DOI: 10.1021/acs.jctc.0c00248] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Walter Malone
- Physics and Chemistry of Materials, Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
- Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Benjamin Nebgen
- Physics and Chemistry of Materials, Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Alexander White
- Physics and Chemistry of Materials, Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Yu Zhang
- Physics and Chemistry of Materials, Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Huajing Song
- Physics and Chemistry of Materials, Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Josiah A. Bjorgaard
- Physics and Chemistry of Materials, Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Andrew E. Sifain
- U.S. Army Research Laboratory, Aberdeen Proving Ground, Aberdeen, Maryland 21005, United States
| | | | - Victor M. Freixas
- Universidad Nacional de Quilmes/CONICET, Roque Saenz Peña 352, B1876BXD Bernal, Argentina
| | | | - Adrian E. Roitberg
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Tammie R. Nelson
- Physics and Chemistry of Materials, Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Sergei Tretiak
- Physics and Chemistry of Materials, Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
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4
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Park KH, Kim W, Yang J, Kim D. Excited-state structural relaxation and exciton delocalization dynamics in linear and cyclic π-conjugated oligothiophenes. Chem Soc Rev 2018; 47:4279-4294. [DOI: 10.1039/c7cs00605e] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
π-Conjugated oligothiophene is considered a chain segment of its polymeric counterpart with simper excited-state dynamics and spectral signatures.
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Affiliation(s)
- Kyu Hyung Park
- Department of Chemistry and Spectroscopy Laboratory for Functional π-Electronic Systems
- Yonsei University
- Seoul 03722
- Korea
| | - Woojae Kim
- Department of Chemistry and Spectroscopy Laboratory for Functional π-Electronic Systems
- Yonsei University
- Seoul 03722
- Korea
| | - Jaesung Yang
- Department of Chemistry and Medical Chemistry
- Yonsei University
- Wonju
- Korea
| | - Dongho Kim
- Department of Chemistry and Spectroscopy Laboratory for Functional π-Electronic Systems
- Yonsei University
- Seoul 03722
- Korea
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5
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Kim W, Sung J, Park KH, Shimizu H, Imamura M, Han M, Sim E, Iyoda M, Kim D. The Role of Linkers in the Excited-State Dynamic Planarization Processes of Macrocyclic Oligothiophene 12-Mers. J Phys Chem Lett 2015; 6:4444-4450. [PMID: 26495968 DOI: 10.1021/acs.jpclett.5b02189] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Linkers adjoining chromophores play an important role in modulating the structure of conjugated systems, which is bound up with their photophysical properties. However, to date, the focus of works dealing with linker effects was limited only to linear π-conjugated materials, and there have been no detailed studies on cyclic counterparts. Herein we report the linker effects on the dynamic planarization processes of π-conjugated macrocyclic oligothiophene 12-mers, where the different ratio between ethynylene and vinylene linkers was chosen to control the backbone rigidity. By analyzing transient fluorescence spectra, we demonstrate that the connecting linkers play a crucial role in the excited-state dynamics of cyclic conjugated systems. Faster dynamic planarization, longer exciton delocalization length, and higher degree of planarity were observed in vinylene inserted cyclic oligothiophenes. Molecular dynamics simulations and density functional theory calculations also stress the importance of the role of linkers in modulating the structure of cyclic oligothiophenes.
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Affiliation(s)
- Woojae Kim
- Department of Chemistry and Spectroscopy Laboratory for Functional π-Electronic Systems, Yonsei University , Seoul 03722, Korea
| | - Jooyoung Sung
- Department of Chemistry and Spectroscopy Laboratory for Functional π-Electronic Systems, Yonsei University , Seoul 03722, Korea
| | - Kyu Hyung Park
- Department of Chemistry and Spectroscopy Laboratory for Functional π-Electronic Systems, Yonsei University , Seoul 03722, Korea
| | - Hideyuki Shimizu
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University , Hachioji, Tokyo 192-0397, Japan
| | - Mika Imamura
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University , Hachioji, Tokyo 192-0397, Japan
| | - Minwoo Han
- Department of Chemistry and Institute of Nano-Bio Molecular Assemblies, Yonsei University , Seoul 03722, Korea
| | - Eunji Sim
- Department of Chemistry and Institute of Nano-Bio Molecular Assemblies, Yonsei University , Seoul 03722, Korea
| | - Masahiko Iyoda
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University , Hachioji, Tokyo 192-0397, Japan
| | - Dongho Kim
- Department of Chemistry and Spectroscopy Laboratory for Functional π-Electronic Systems, Yonsei University , Seoul 03722, Korea
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6
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Nelson T, Fernandez-Alberti S, Roitberg AE, Tretiak S. Nonadiabatic excited-state molecular dynamics: modeling photophysics in organic conjugated materials. Acc Chem Res 2014; 47:1155-64. [PMID: 24673100 DOI: 10.1021/ar400263p] [Citation(s) in RCA: 172] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To design functional photoactive materials for a variety of technological applications, researchers need to understand their electronic properties in detail and have ways to control their photoinduced pathways. When excited by photons of light, organic conjugated materials (OCMs) show dynamics that are often characterized by large nonadiabatic (NA) couplings between multiple excited states through a breakdown of the Born-Oppenheimer (BO) approximation. Following photoexcitation, various nonradiative intraband relaxation pathways can lead to a number of complex processes. Therefore, computational simulation of nonadiabatic molecular dynamics is an indispensable tool for understanding complex photoinduced processes such as internal conversion, energy transfer, charge separation, and spatial localization of excitons. Over the years, we have developed a nonadiabatic excited-state molecular dynamics (NA-ESMD) framework that efficiently and accurately describes photoinduced phenomena in extended conjugated molecular systems. We use the fewest-switches surface hopping (FSSH) algorithm to treat quantum transitions among multiple adiabatic excited state potential energy surfaces (PESs). Extended molecular systems often contain hundreds of atoms and involve large densities of excited states that participate in the photoinduced dynamics. We can achieve an accurate description of the multiple excited states using the configuration interaction single (CIS) formalism with a semiempirical model Hamiltonian. Analytical techniques allow the trajectory to be propagated "on the fly" using the complete set of NA coupling terms and remove computational bottlenecks in the evaluation of excited-state gradients and NA couplings. Furthermore, the use of state-specific gradients for propagation of nuclei on the native excited-state PES eliminates the need for simplifications such as the classical path approximation (CPA), which only uses ground-state gradients. Thus, the NA-ESMD methodology offers a computationally tractable route for simulating hundreds of atoms on ~10 ps time scales where multiple coupled excited states are involved. In this Account, we review recent developments in the NA-ESMD modeling of photoinduced dynamics in extended conjugated molecules involving multiple coupled electronic states. We have successfully applied the outlined NA-ESMD framework to study ultrafast conformational planarization in polyfluorenes where the rate of torsional relaxation can be controlled based on the initial excitation. With the addition of the state reassignment algorithm to identify instances of unavoided crossings between noninteracting PESs, NA-ESMD can now be used to study systems in which these so-called trivial unavoided crossings are expected to predominate. We employ this technique to analyze the energy transfer between poly(phenylene vinylene) (PPV) segments where conformational fluctuations give rise to numerous instances of unavoided crossings leading to multiple pathways and complex energy transfer dynamics that cannot be described using a simple Förster model. In addition, we have investigated the mechanism of ultrafast unidirectional energy transfer in dendrimers composed of poly(phenylene ethynylene) (PPE) chromophores and have demonstrated that differential nuclear motion favors downhill energy transfer in dendrimers. The use of native excited-state gradients allows us to observe this feature.
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Affiliation(s)
- Tammie Nelson
- Los Alamos National Laboratory, Theoretical
Division, Los Alamos, New Mexico 87545, United States
| | | | - Adrian E. Roitberg
- Quantum Theory Project, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Sergei Tretiak
- Los Alamos National Laboratory, Theoretical
Division, Los Alamos, New Mexico 87545, United States
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7
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Al Ouahabi A, Baxter P, Mathis C, Bernard M, Vileno B, Gisselbrecht JP, Turek P, Mouesca JM, Choua S. Experimental and theoretical study of the n-doped successive polyanions of oligocruciform molecular wires: up to five units of charge. Chemphyschem 2013; 14:958-69. [PMID: 23401358 DOI: 10.1002/cphc.201200848] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Indexed: 11/07/2022]
Abstract
The electronic structure of polyanions of sterically encumbered triisopropylsilyl-substituted linear and cyclic oligo(phenyleneethynylene)s (Monomer, Trimer, Pentamer, and Triangle) is investigated by electron paramagnetic resonance (EPR), electron nuclear double resonance (ENDOR), and UV/Vis-near-infrared (NIR) spectroscopies, cyclic voltammetry, and theoretical calculations (DFT). Increasing anion orders are generated sequentially in vacuo at room temperature by chemical reaction with potassium metal up to the pentaanion. The relevance of these compounds acting as electron reservoirs is thus demonstrated. Even-order anions are EPR silent, whereas the odd species exhibit different signatures, which are identified after comparison of the measured hyperfine couplings by ENDOR spectroscopy with those predicted by DFT calculations. With increasing size of the oligomers the electron spin density is first distributed over the backbone carbon atoms for the monoanions, and then further localized at the outer phenyl rings for the trianion species. Examination of the UV/Vis-NIR spectra indicates that the monoanions (T(.-) , P(.-) ) exhibit two transitions in the Vis-NIR region, whereas a strong absorption in the IR region is solely observed for higher reduced states. Electronic transitions of the neutral monoanions and trianions are redshifted with increasing oligomer size, whereas for a given oligomer a blueshift is observed upon increasing the charge, which suggests a localization of the spin density.
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Affiliation(s)
- Abdelaziz Al Ouahabi
- Institut Charles Sadron, CNRS, UPR 22, 23 rue du Loess, 67034 Strasbourg, France
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8
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Macernis M, Sulskus J, Duffy CDP, Ruban AV, Valkunas L. Electronic Spectra of Structurally Deformed Lutein. J Phys Chem A 2012; 116:9843-53. [DOI: 10.1021/jp304363q] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Mindaugas Macernis
- Theoretical Physics Department,
Faculty of Physics, Vilnius University,
Saulėtekio al. 9, LT-10222 Vilnius, Lithuania
- Center for Physical Sciences and Technology, Savanorių 231, LT-02300
Vilnius, Lithuania
| | - Juozas Sulskus
- Theoretical Physics Department,
Faculty of Physics, Vilnius University,
Saulėtekio al. 9, LT-10222 Vilnius, Lithuania
| | - Christopher D. P. Duffy
- School
of Biological and Chemical
Sciences, Queen Mary University of London, Mile End Road, London E1 4TN, U.K
| | - Alexander V. Ruban
- School
of Biological and Chemical
Sciences, Queen Mary University of London, Mile End Road, London E1 4TN, U.K
| | - Leonas Valkunas
- Theoretical Physics Department,
Faculty of Physics, Vilnius University,
Saulėtekio al. 9, LT-10222 Vilnius, Lithuania
- Center for Physical Sciences and Technology, Savanorių 231, LT-02300
Vilnius, Lithuania
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9
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Nelson T, Fernandez-Alberti S, Chernyak V, Roitberg AE, Tretiak S. Nonadiabatic Excited-State Molecular Dynamics Modeling of Photoinduced Dynamics in Conjugated Molecules. J Phys Chem B 2011; 115:5402-14. [DOI: 10.1021/jp109522g] [Citation(s) in RCA: 158] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Tammie Nelson
- Theoretical Division, Center for Nonlinear Studies (CNLS), and Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | | | - Vladimir Chernyak
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, Michigan 48202, United States
| | - Adrian E. Roitberg
- Departments of Physics and Chemistry, Quantum Theory Project, University of Florida, Gainesville, Florida 32611, United States
| | - Sergei Tretiak
- Theoretical Division, Center for Nonlinear Studies (CNLS), and Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
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10
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Dykstra TE, Hennebicq E, Beljonne D, Gierschner J, Claudio G, Bittner ER, Knoester J, Scholes GD. Conformational disorder and ultrafast exciton relaxation in PPV-family conjugated polymers. J Phys Chem B 2009; 113:656-67. [PMID: 19105646 DOI: 10.1021/jp807249b] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
We report combined experimental and theoretical studies of excitation relaxation in poly[2-methoxy,5-(2'-ethyl-hexoxy)-1,4-phenylenevinylene] (MEH-PPV), oligophenylenevinylene (OPV) molecules of varying length, and model PPV chains. We build on the paradigm that the basic characteristics of conjugated polymers are decided by conformational subunits defined by conjugation breaks caused by torsional disorder along the chain. The calculations reported here indicate that for conjugated polymers like those in the PPV family, these conformational subunits electronically couple to neighboring subunits, forming subtly delocalized collective states of nanoscale excitons that determine the polymer optical properties. We find that relaxation among these exciton states can lead to a decay of anisotropy on ultrafast time scales. Unlike in Forster energy transfer, the exciton does not necessarily translate over a large distance. Nonetheless, the disorder in the polymer chain means that even small changes in the exciton size or location has a significant effect on the relaxation pathway and therefore the anisotropy decay.
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Affiliation(s)
- Tieneke E Dykstra
- Lash-Miller Chemical Laboratories, Institute for Optical Sciences and Centre for Quantum Information and Quantum Control, University of Toronto, 80 St. George Street, Toronto, Ontario, M5S 3H6 Canada
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11
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Collini E, Scholes GD. Electronic and Vibrational Coherences in Resonance Energy Transfer along MEH-PPV Chains at Room Temperature. J Phys Chem A 2009; 113:4223-41. [DOI: 10.1021/jp810757x] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Elisabetta Collini
- Lash-Miller Chemical Laboratories, Institute for Optical Sciences and Centre for Quantum Information and Quantum Control, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
| | - Gregory D. Scholes
- Lash-Miller Chemical Laboratories, Institute for Optical Sciences and Centre for Quantum Information and Quantum Control, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
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12
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Takagi K, Saiki K, Hayashi H, Ohsawa H, Matsuoka SI, Suzuki M. Tropolone-Terminated Oligomeric Fluorophores with Responsive Properties to External Environment. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2009. [DOI: 10.1246/bcsj.82.236] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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13
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Li N, Jia K, Wang S, Xia A. Theoretical Study of Spectroscopic Properties of Dimethoxy-p-Phenylene-Ethynylene Oligomers: Planarization of the Conjugated Backbone. J Phys Chem A 2007; 111:9393-8. [PMID: 17711272 DOI: 10.1021/jp074013b] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The optical spectra of the dimethoxy-p-phenylene-ethynylene oligomers (up to n = 10) are calculated by DFT and TD-DFT methods. It is found that the conformational rotations around the cylindrical triple-bonded carbon links impact significantly the optical spectrum. The effective conjugation length (ECL) of the oligomer is obtained by extrapolating the HOMO-LUMO gap to infinite chain length with an alternative exponential function. The spectral shift is mainly dependent on the high pi-conjugation segment of oligomers, resulting from the planarization of the backbone. Although the rotational barrier is very low, the calculated results further indicate that rotation about the cylindrical triple bond still interrupts the conjugation of rod-like oligomers to some extent, and leads to an angle-dependent HOMO-LUMO gap. The results are helpful to interpret the conformational-dependent spectroscopic phenomena of p-phenyleneethynylene oligomers and polymers (PPEs) observed in ensemble and single molecule spectroscopy.
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Affiliation(s)
- Na Li
- The State Key Laboratory of Molecular Reaction Dynamics, and Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing-100 080, P. R. China
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14
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Saha B, Ehara M, Nakatsuji H. Investigation of the Electronic Spectra and Excited-State Geometries of Poly(para-phenylene vinylene) (PPV) and Poly(para-phenylene) (PP) by the Symmetry-Adapted Cluster Configuration Interaction (SAC-CI) Method. J Phys Chem A 2007; 111:5473-81. [PMID: 17542562 DOI: 10.1021/jp068441d] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The symmetry-adapted cluster-configuration interaction (SAC-CI) method has been used to investigate the optical and geometric properties of the oligomers of poly(para-phenylene vinylene) (PPV) and poly(para-phenylene) (PP). Vertical singlet and triplet absorption spectra and emission spectra have been calculated accurately; the mean average deviation from available experimental results lies within 0.2 eV. The chain length dependence of the transition energies has been improved in comparison to earlier TDDFT and MRSDCI calculations. The present analysis suggests that conventional TDDFT with the B3LYP functional should be used carefully, as it can provide inaccurate estimates of the chain length dependence of the excitation energies of these molecules with long pi conjugation. The T1 state was predicted to be at a lower energy, by 1.0-1.5 eV for PPV and by 0.9-1.7 eV for PP, than the S1 state, which indicates a localized T1 state with large exchange energy. By calculating the SAC-CI electron density difference between the ground and excited states, the geometry relaxations due to excitations can be analyzed in detail using electrostatic force theory. For trans-stilbene, the doubly excited 21Ag state was studied, and the calculated transition energy of 4.99 eV agrees very well with the experimental value of 4.84 eV. In contrast to previous ab initio calculations, we predict this doubly excited 21Ag state to lie above the 11Bu state.
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Affiliation(s)
- Biswajit Saha
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
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15
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Kim H, Hwang H, Rossky PJ. Quantum Simulation of Solution Phase Intramolecular Electron Transfer Rates in Betaine-30. J Phys Chem A 2006; 110:11223-9. [PMID: 17004730 DOI: 10.1021/jp063222d] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mixed quantum-classical atomistic simulations have been carried out to investigate the mechanistic details of excited state intramolecular electron transfer in a betaine-30 molecule in acetonitrile. The key electronic degrees of freedom of the solute molecule are treated quantum mechanically using the semiempirical Pariser-Parr-Pople Hamiltonian, including the solvent influence on electronic structure. The intramolecular vibrational modes are also treated explicitly at a quantum level, with the remaining elements treated classically using empirical potentials. The electron-transfer rate, corresponding to S1 --> S0 relaxation, is evaluated via time-dependent perturbation theory with the explicit inclusion of the dynamics of solvation and intramolecular conformation. The calculations reveal that, while solvation dynamics is critical to the rate, the intramolecular torsional dynamics also plays an important role. The importance of the use of multiple high-frequency quantum modes is also discussed.
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Affiliation(s)
- Hyojoon Kim
- Chemical Physics Theory Group, Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada.
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16
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Liu LT, Yaron D, Sluch MI, Berg MA. Modeling the Effects of Torsional Disorder on the Spectra of Poly- and Oligo-(p-phenyleneethynylenes). J Phys Chem B 2006; 110:18844-52. [PMID: 16986875 DOI: 10.1021/jp056284x] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The absorption spectra of phenyleneethynylene oligomers show an unusual change in shape with oligomer length. The unusual aspects of the spectra arise from rotation of the phenylene rings about the long axis of the oligomer. In the ground electronic state, the barrier to this rotation is low and the spectra in room temperature come from an ensemble of different structures. In the excited electronic state, the barrier to rotation is substantially higher, giving rise to strong nonlinear electron-phonon coupling. A multidimensional semiempirical model that includes these effects is developed for the photophysics of phenyleneethynylene oligomers. The ground-state energy is modeled with a molecular mechanics expression, and the excitation energy is modeled with an exciton model. Intermediate Neglect of Differential Overlap/Singles Configuration Interaction (INDO/SCI) calculations verify the exciton model and provide initial estimates of the model parameters. These parameters generate the qualitative features seen in experimental spectra. Inclusion of entropy effects from the multiple torsional coordinates is essential. Refinement of the parameters yields quantitative agreement with experiment. This agreement shows that coupling to torsional motion is a major factor in the spectroscopy and photophysics of these conjugated polymers.
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Affiliation(s)
- Lu Tian Liu
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
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17
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Armitt DJ, Crisp GT. Synthesis and Optical Properties of Bis(oligophenyleneethynylenes). J Org Chem 2006; 71:3417-22. [PMID: 16626121 DOI: 10.1021/jo052242t] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Bis(oligophenyleneethynylenes) 1-4 were prepared as representative members of a new class of potential nonlinear optical materials. The optical properties of 1-4 were examined for evidence of restricted rotation of the aryl rings when compared to their single-strand precursors, which could potentially increase their nonlinear response through more effective conjugation. The effect of altering the electron density of the terminating functional group of these compounds on their properties was also investigated.
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Affiliation(s)
- David J Armitt
- School of Chemistry and Physics, University of Adelaide, Adelaide, South Australia 5005, Australia.
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18
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Excited state dynamics of a conformationally disordered conjugated polymer: A comparison of solutions and film. Chem Phys 2005. [DOI: 10.1016/j.chemphys.2005.04.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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19
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Anand S, Varnavski O, Marsden JA, Haley MM, Schlegel HB, Goodson T. Optical Excitations in Carbon Architectures Based on Dodecadehydrotribenzo[18]annulene. J Phys Chem A 2005; 110:1305-18. [PMID: 16435791 DOI: 10.1021/jp0539573] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The origin of excitations in multi-chromophore carbon network substructures based on dodecadehydrotribenzo[18]annulene has been investigated by steady-state and photon echo spectroscopy, configuration interaction (CIS and CIS(D)), and time-dependent density functional theory (TD-DFT). 1,4-diphenylbutadiyne, the simplest structural subunit within the annulene, was used in modeling the spectroscopic studies to explain the origin of excitations in the macrocycles. The optical excitations in longer linear systems were found to be similar to its diphenylacetylene analogue. However, the results from dodecadehydrotribenzo[18]annulene and other multichromophore networks systems illustrate the possibility of strong intramolecular interactions and the formation of delocalized excited states. Calculations were carried out to explain the basic similarities and differences in excitations of the model compounds such as diphenylbutadiyne and the macrocycles. The fundamental excitation in these systems can be primarily described as a pi --> pi* transition. Two low-energy resonances were observed from experiment for the annulene systems, and possible explanations for these low-energy resonances in the macrocycles are explored. The significant difference found in the calculated oscillator strength of the two low-energy bands for the macrocycles as well as the dynamics of solvent interactions was further investigated by three-pulse photon echo measurements. A simple exciton model was developed to discuss the excitations in the larger macrocycles. The results from this model were found to be in good agreement with the TD-DFT calculations.
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Affiliation(s)
- Smriti Anand
- Department of Chemistry and Institute for Scientific Computing, Wayne State University, Detroit, Michigan 48202, USA
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20
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Vendrame R, Coluci V, Galvão D. Comparative parametric method 5 (PM5) study of trans-stilbene. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/j.theochem.2004.08.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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21
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Wong KF, Bagchi B, Rossky PJ. Distance and Orientation Dependence of Excitation Transfer Rates in Conjugated Systems: Beyond the Förster Theory. J Phys Chem A 2004. [DOI: 10.1021/jp037724s] [Citation(s) in RCA: 202] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kim F. Wong
- Institute for Theoretical Chemistry, Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712-1167
| | - Biman Bagchi
- Institute for Theoretical Chemistry, Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712-1167
| | - Peter J. Rossky
- Institute for Theoretical Chemistry, Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712-1167
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22
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Han YK, Lee SU. Time-dependent density-functional calculations of S[sub 0]–S[sub 1] transition energies of poly(p-phenylene vinylene). J Chem Phys 2004; 121:609-11. [PMID: 15260583 DOI: 10.1063/1.1737297] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We used time-dependent density-functional-theory (TDDFT) approaches to calculate absorption (S(0)-->S(1)) and emission (S(1)-->S(0)) transition energies of poly(p-phenylene vinylene) (PPV). The absorption and emission energies were estimated to be 2.44 and 2.16 eV, respectively, from the extrapolation of calculated results for oligomers. Comparisons with available experimental data demonstrated that TDDFT is a very reliable tool for investigating the electronic transitions of PPV.
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Affiliation(s)
- Young-Kyu Han
- Computational Chemistry Laboratory, Corporate R&D, LG Chem, Ltd. Research Park, Daejeon, 305-380, South Korea.
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23
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Claudio GC, Bittner ER. Excitation Transfer in Aggregated and Linearly Confined Poly(p-phenylene vinylene) Chains. J Phys Chem A 2003. [DOI: 10.1021/jp027746z] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gil C. Claudio
- Department of Chemistry, University of Houston, Houston, Texas 77204
| | - Eric R. Bittner
- Department of Chemistry, University of Houston, Houston, Texas 77204
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24
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Karabunarliev S, Bittner ER. Polaron–excitons and electron–vibrational band shapes in conjugated polymers. J Chem Phys 2003. [DOI: 10.1063/1.1543938] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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25
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Karabunarliev S, Bittner ER. Spin-dependent electron-hole capture kinetics in luminescent conjugated polymers. PHYSICAL REVIEW LETTERS 2003; 90:057402. [PMID: 12633395 DOI: 10.1103/physrevlett.90.057402] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2002] [Indexed: 05/24/2023]
Abstract
The recombination of electron-hole pairs injected in extended conjugated systems is modeled as a multistep interconversion relaxation in monoexcited electronic state space, mediated by electron-phonon coupling. The computed ratio of triplet-to-singlet exciton formation times r=tau(T)/tau(S) increases from 0.9 for a model dimer to 2.5 for a 32-unit chain, in good agreement with recent experiments. We rationalize the conjugation-length dependence of r in terms of spin-specific energetics and mutual vibronic coupling of the excited states.
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Affiliation(s)
- Stoyan Karabunarliev
- Department of Chemistry and Center for Materials Chemistry, University of Houston, Texas 77204-5003, USA.
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26
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Pond SJK, Rumi M, Levin MD, Parker TC, Beljonne D, Day MW, Brédas JL, Marder SR, Perry JW. One- and Two-Photon Spectroscopy of Donor−Acceptor−Donor Distyrylbenzene Derivatives: Effect of Cyano Substitution and Distortion from Planarity. J Phys Chem A 2002. [DOI: 10.1021/jp0267104] [Citation(s) in RCA: 203] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Stephanie J. K. Pond
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721, Center for Research on Molecular Electronics and Photonics, Université de Mons-Hainaut, B-7000, Mons, Belgium, Division of Chemistry and Chemical Engineering and Beckman Institute, California Institute of Technology, Pasadena, California 91125, and Optical Sciences Center, University of Arizona, Tucson, Arizona 85721
| | - Mariacristina Rumi
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721, Center for Research on Molecular Electronics and Photonics, Université de Mons-Hainaut, B-7000, Mons, Belgium, Division of Chemistry and Chemical Engineering and Beckman Institute, California Institute of Technology, Pasadena, California 91125, and Optical Sciences Center, University of Arizona, Tucson, Arizona 85721
| | - Michael D. Levin
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721, Center for Research on Molecular Electronics and Photonics, Université de Mons-Hainaut, B-7000, Mons, Belgium, Division of Chemistry and Chemical Engineering and Beckman Institute, California Institute of Technology, Pasadena, California 91125, and Optical Sciences Center, University of Arizona, Tucson, Arizona 85721
| | - Timothy C. Parker
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721, Center for Research on Molecular Electronics and Photonics, Université de Mons-Hainaut, B-7000, Mons, Belgium, Division of Chemistry and Chemical Engineering and Beckman Institute, California Institute of Technology, Pasadena, California 91125, and Optical Sciences Center, University of Arizona, Tucson, Arizona 85721
| | - David Beljonne
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721, Center for Research on Molecular Electronics and Photonics, Université de Mons-Hainaut, B-7000, Mons, Belgium, Division of Chemistry and Chemical Engineering and Beckman Institute, California Institute of Technology, Pasadena, California 91125, and Optical Sciences Center, University of Arizona, Tucson, Arizona 85721
| | - Michael W. Day
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721, Center for Research on Molecular Electronics and Photonics, Université de Mons-Hainaut, B-7000, Mons, Belgium, Division of Chemistry and Chemical Engineering and Beckman Institute, California Institute of Technology, Pasadena, California 91125, and Optical Sciences Center, University of Arizona, Tucson, Arizona 85721
| | - Jean-Luc Brédas
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721, Center for Research on Molecular Electronics and Photonics, Université de Mons-Hainaut, B-7000, Mons, Belgium, Division of Chemistry and Chemical Engineering and Beckman Institute, California Institute of Technology, Pasadena, California 91125, and Optical Sciences Center, University of Arizona, Tucson, Arizona 85721
| | - Seth R. Marder
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721, Center for Research on Molecular Electronics and Photonics, Université de Mons-Hainaut, B-7000, Mons, Belgium, Division of Chemistry and Chemical Engineering and Beckman Institute, California Institute of Technology, Pasadena, California 91125, and Optical Sciences Center, University of Arizona, Tucson, Arizona 85721
| | - Joseph W. Perry
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721, Center for Research on Molecular Electronics and Photonics, Université de Mons-Hainaut, B-7000, Mons, Belgium, Division of Chemistry and Chemical Engineering and Beckman Institute, California Institute of Technology, Pasadena, California 91125, and Optical Sciences Center, University of Arizona, Tucson, Arizona 85721
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27
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Tretiak S, Saxena A, Martin RL, Bishop AR. Conformational dynamics of photoexcited conjugated molecules. PHYSICAL REVIEW LETTERS 2002; 89:097402. [PMID: 12190437 DOI: 10.1103/physrevlett.89.097402] [Citation(s) in RCA: 251] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2001] [Indexed: 05/23/2023]
Abstract
Time-dependent photoexcitation and optical spectroscopy of pi-conjugated molecules is described using a new method for the simulation of excited state molecular dynamics in extended molecular systems with sizes up to hundreds of atoms. Applications are made to poly(p-phenylene vinylene) oligomers. Our analysis shows self-trapping of excitations on about six repeat units in the course of photoexcitation relaxation, identifies specific slow (torsion) and fast (bond-stretch) nuclear motions strongly coupled to the electronic degrees of freedom, and predicts spectroscopic signatures of molecular conformations.
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Affiliation(s)
- S Tretiak
- Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
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28
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Gierschner J, Mack HG, Lüer L, Oelkrug D. Fluorescence and absorption spectra of oligophenylenevinylenes: Vibronic coupling, band shapes, and solvatochromism. J Chem Phys 2002. [DOI: 10.1063/1.1469612] [Citation(s) in RCA: 252] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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29
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Sluch MI, Godt A, Bunz UH, Berg MA. Excited-state dynamics of oligo(p-phenyleneethynylene): quadratic coupling and torsional motions. J Am Chem Soc 2001; 123:6447-8. [PMID: 11427084 DOI: 10.1021/ja0159012] [Citation(s) in RCA: 157] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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30
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Wong KF, Skaf MS, Yang CY, Rossky PJ, Bagchi B, Hu D, Yu J, Barbara PF. Structural and Electronic Characterization of Chemical and Conformational Defects in Conjugated Polymers. J Phys Chem B 2001. [DOI: 10.1021/jp010392b] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kim F. Wong
- Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712-1167
| | - Munir S. Skaf
- Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712-1167
| | - Chao-Yie Yang
- Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712-1167
| | - Peter J. Rossky
- Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712-1167
| | - Biman Bagchi
- Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712-1167
| | - Dehong Hu
- Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712-1167
| | - Ji Yu
- Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712-1167
| | - Paul F. Barbara
- Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712-1167
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31
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Karabunarliev S, Bittner ER, Baumgarten M. Franck–Condon spectra and electron-libration coupling in para-polyphenyls. J Chem Phys 2001. [DOI: 10.1063/1.1351853] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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32
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Karabunarliev S, Baumgarten M, Bittner ER, Müllen K. Rigorous Franck–Condon absorption and emission spectra of conjugated oligomers from quantum chemistry. J Chem Phys 2000. [DOI: 10.1063/1.1328067] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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