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Picconi D. Quantum dynamics of the photoinduced charge separation in a symmetric donor–acceptor–donor triad: The role of vibronic couplings, symmetry and temperature. J Chem Phys 2022; 156:184105. [DOI: 10.1063/5.0089887] [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
The photoinduced charge separation in a symmetric donor–acceptor–donor (D–A–D) triad is studied quantum mechanically using a realistic diabatic vibronic coupling model. The model includes a locally excited DA*D state and two charge-transfer states D+A−D and DA−D+ and is constructed according to a procedure generally applicable to semirigid D–A–D structures and based on energies, forces, and force constants obtained by quantum chemical calculations. In this case, the electronic structure is described by time-dependent density functional theory, and the corrected linear response is used in conjunction with the polarizable continuum model to account for state-specific solvent effects. The multimode dynamics following the photoexcitation to the locally excited state are simulated by the hybrid Gaussian-multiconfigurational time-dependent Hartree method, and temperature effects are included using thermo field theory. The dynamics are connected to the transient absorption spectrum obtained in recent experiments, which is simulated and fully assigned from first principles. It is found that the charge separation is mediated by symmetry-breaking vibrations of relatively low frequency, which implies that temperature should be accounted for to obtain reliable estimates of the charge transfer rate.
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Affiliation(s)
- David Picconi
- Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam-Golm, Germany and Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam-Golm, Germany
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2
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Kemp DJ, Warner LG, Wright TG. Torsions, low-frequency vibrations, and vibration–torsion (“vibtor”) levels in the m-chlorotoluene cation. J Chem Phys 2020; 152:064303. [DOI: 10.1063/1.5142992] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- David J. Kemp
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Lewis G. Warner
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Timothy G. Wright
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
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3
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Gardner AM, Whalley LE, Kemp DJ, Tuttle WD, Wright TG. Identification of separate isoenergetic routes for vibrational energy flow in p-fluorotoluene. J Chem Phys 2019; 151:154302. [DOI: 10.1063/1.5126179] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Adrian M. Gardner
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Laura E. Whalley
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - David J. Kemp
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - William D. Tuttle
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Timothy G. Wright
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
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4
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Kemp DJ, Fryer EF, Davies AR, Wright TG. Vibration-modified torsional potentials and vibration-torsion (“vibtor”) levels in them-fluorotoluene cation. J Chem Phys 2019; 151:084311. [DOI: 10.1063/1.5116520] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- David J. Kemp
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Elizabeth F. Fryer
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Alexander R. Davies
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Timothy G. Wright
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
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5
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Kemp DJ, Tuttle WD, Gardner AM, Whalley LE, Wright TG. Observation of the onset of torsion-induced, mode-specific dissipative intramolecular vibrational redistribution (IVR). J Chem Phys 2019. [DOI: 10.1063/1.5115329] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- David J. Kemp
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - William D. Tuttle
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Adrian M. Gardner
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Laura E. Whalley
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Timothy G. Wright
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
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Stewart LD, Gascooke JR, Lawrance WD. A strong interaction between torsion and vibration in S0 and S1 m-fluorotoluene. J Chem Phys 2019; 150:174303. [DOI: 10.1063/1.5094454] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Laurence D. Stewart
- College of Science and Engineering, Flinders University, G.P.O. Box 2100, Adelaide SA 5001, Australia
| | - Jason R. Gascooke
- College of Science and Engineering, Flinders University, G.P.O. Box 2100, Adelaide SA 5001, Australia
| | - Warren D. Lawrance
- College of Science and Engineering, Flinders University, G.P.O. Box 2100, Adelaide SA 5001, Australia
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Kemp DJ, Whalley LE, Gardner AM, Tuttle WD, Warner LG, Wright TG. Complexity surrounding an apparently simple Fermi resonance in p-fluorotoluene revealed using two-dimensional laser-induced fluorescence (2D-LIF) spectroscopy. J Chem Phys 2019; 150:064306. [DOI: 10.1063/1.5083682] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- David J. Kemp
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Laura E. Whalley
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Adrian M. Gardner
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - William D. Tuttle
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Lewis G. Warner
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Timothy G. Wright
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
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8
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Tuttle WD, Gardner AM, Whalley LE, Kemp DJ, Wright TG. Effects of symmetry, methyl groups and serendipity on intramolecular vibrational energy dispersal. Phys Chem Chem Phys 2019; 21:14133-14152. [DOI: 10.1039/c8cp02757a] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Intramolecular vibrational dispersal of vibrational energy is more efficient in the symmetrically-substituted p-xylene molecule than in p-fluorotoluene, p-chlorofluorobenzene or p-difluorobenzene.
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Affiliation(s)
- William D. Tuttle
- School of Chemistry, University of Nottingham, University Park
- Nottingham
- UK
| | - Adrian M. Gardner
- School of Chemistry, University of Nottingham, University Park
- Nottingham
- UK
| | - Laura E. Whalley
- School of Chemistry, University of Nottingham, University Park
- Nottingham
- UK
| | - David J. Kemp
- School of Chemistry, University of Nottingham, University Park
- Nottingham
- UK
| | - Timothy G. Wright
- School of Chemistry, University of Nottingham, University Park
- Nottingham
- UK
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9
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Kemp DJ, Gardner AM, Tuttle WD, Wright TG. Unravelling overlaps and torsion-facilitated coupling using two-dimensional laser-induced fluorescence. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1554865] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- David J. Kemp
- School of Chemistry, University of Nottingham, Nottingham, UK
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Kemp DJ, Gardner AM, Tuttle WD, Midgley J, Reid KL, Wright TG. Identifying complex Fermi resonances in p-difluorobenzene using zero-electron-kinetic-energy (ZEKE) spectroscopy. J Chem Phys 2018; 149:094301. [DOI: 10.1063/1.5045544] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- David J. Kemp
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Adrian M. Gardner
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - William D. Tuttle
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Jonathan Midgley
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Katharine L. Reid
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Timothy G. Wright
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
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11
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Gascooke JR, Stewart LD, Sibley PG, Lawrance WD. Pervasive interactions between methyl torsion and low frequency vibrations in S0 and S1 p-fluorotoluene. J Chem Phys 2018; 149:074301. [DOI: 10.1063/1.5035461] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Jason R. Gascooke
- College of Science and Engineering, Flinders University, G.P.O. Box 2100, Adelaide, SA 5001, Australia
| | - Laurence D. Stewart
- College of Science and Engineering, Flinders University, G.P.O. Box 2100, Adelaide, SA 5001, Australia
| | - Paul G. Sibley
- College of Science and Engineering, Flinders University, G.P.O. Box 2100, Adelaide, SA 5001, Australia
| | - Warren D. Lawrance
- College of Science and Engineering, Flinders University, G.P.O. Box 2100, Adelaide, SA 5001, Australia
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12
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Gardner AM, Tuttle WD, Whalley LE, Wright TG. Direct observation of vibrational energy dispersal via methyl torsions. Chem Sci 2018; 9:2270-2283. [PMID: 29719700 PMCID: PMC5897844 DOI: 10.1039/c7sc05309f] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 01/24/2018] [Indexed: 01/01/2023] Open
Abstract
Explicit evidence for the role of methyl rotor levels in promoting energy dispersal is reported. A set of coupled zero-order vibration/vibration-torsion (vibtor) levels in the S1 state of para-fluorotoluene (pFT) are investigated. Two-dimensional laser-induced fluorescence (2D-LIF) and two-dimensional zero-kinetic-energy (2D-ZEKE) spectra are reported, and the assignment of the main features in both sets of spectra reveals that the methyl torsion is instrumental in providing a route for coupling between vibrational levels of different symmetry classes. We find that there is very localized, and selective, dissipation of energy via doorway states, and that, in addition to an increase in the density of states, a critical role of the methyl group is a relaxation of symmetry constraints compared to direct vibrational coupling.
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Affiliation(s)
- Adrian M Gardner
- School of Chemistry , University of Nottingham , University Park , Nottingham NG7 2RD , UK .
| | - William D Tuttle
- School of Chemistry , University of Nottingham , University Park , Nottingham NG7 2RD , UK .
| | - Laura E Whalley
- School of Chemistry , University of Nottingham , University Park , Nottingham NG7 2RD , UK .
| | - Timothy G Wright
- School of Chemistry , University of Nottingham , University Park , Nottingham NG7 2RD , UK .
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Kemp DJ, Whalley LE, Tuttle WD, Gardner AM, Speake BT, Wright TG. Vibrations of the p-chlorofluorobenzene cation. Phys Chem Chem Phys 2018; 20:12503-12516. [DOI: 10.1039/c8cp01274a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Vibrational wavenumbers are established for twenty modes of the p-chlorofluorbenzene cation and two Fermi resonances are identified in the S1 state.
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Affiliation(s)
- David J. Kemp
- School of Chemistry
- University of Nottingham
- Nottingham
- UK
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15
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Tuttle WD, Gardner AM, Whalley LE, Wright TG. Vibration and vibration-torsion levels of the S 1 state of para-fluorotoluene in the 580-830 cm -1 range: Interactions and coincidences. J Chem Phys 2017; 146:244310. [PMID: 28668017 DOI: 10.1063/1.4986862] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
A study of the vibration and vibration-torsion levels of para-fluorotoluene in the 580-830 cm-1 region is presented, where a number of features are located whose identity is complicated by interactions and overlap. We examine this region with a view to ascertaining the assignments of the bands; in particular, identifying those that arise from interactions involving various zero-order states (ZOSs) involving both vibrations and torsions. Resonance-enhanced multiphoton ionization (REMPI) is employed to identify the wavenumbers of the relevant transitions, and subsequently zero-kinetic-energy (ZEKE) spectra are recorded to assign the various eigenstates. In some cases, a set of ZEKE spectra are recorded across the wavenumber range of a REMPI feature, and we construct what we term a two-dimensional ZEKE (2D-ZEKE) spectrum, which allows the changing ZOS contributions to the eigenstates to be ascertained. Assignment of the observed bands is aided by quantum chemical calculations and all b1 and a2 symmetry vibrational wavenumbers are now determined in the S1 state and cation, as well as those of the D10 vibration. We also compare to the activity seen in the corresponding S1 ← S0 spectrum of para-difluorobenzene.
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Affiliation(s)
- William D Tuttle
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Adrian M Gardner
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Laura E Whalley
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Timothy G Wright
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
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Gardner AM, Tuttle WD, Groner P, Wright TG. Molecular symmetry group analysis of the low-wavenumber torsions and vibration-torsions in the S 1 state and ground state cation of p-xylene: An investigation using resonance-enhanced multiphoton ionization (REMPI) and zero-kinetic-energy (ZEKE) spectroscopy. J Chem Phys 2017; 146:124308. [PMID: 28388144 DOI: 10.1063/1.4977896] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
For the first time, a molecular symmetry group (MSG) analysis has been undertaken in the investigation of the electronic spectroscopy of p-xylene (p-dimethylbenzene). Torsional and vibration-torsional (vibtor) levels in the S1 state and ground state of the cation of p-xylene are investigated using resonance-enhanced multiphoton ionization (REMPI) and zero-kinetic-energy (ZEKE) spectroscopy. In the present work, we concentrate on the 0-350 cm-1 region, where there are a number of torsional and vibtor bands and we discuss the assignment of this region. In Paper II [W. D. Tuttle et al., J. Chem. Phys. 146, 124309 (2017)], we examine the 350-600 cm-1 region where vibtor levels are observed as part of a Fermi resonance. The similarity of much of the observed spectral activity to that in the related substituted benzenes, toluene and para-fluorotoluene, is striking, despite the different symmetries. The discussion necessitates a consideration of the MSG of p-xylene, which has been designated G72, but we shall also designate [{3,3}]D2h and we include the symmetry operations, character table, and direct product table for this. We also discuss the symmetries of the internal rotor (torsional) levels and the selection rules for the particular electronic transition of p-xylene investigated here.
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Affiliation(s)
- Adrian M Gardner
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - William D Tuttle
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Peter Groner
- Department of Chemistry, University of Missouri-Kansas City, Kansas City, Missouri 64110, USA
| | - Timothy G Wright
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
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