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Wumaierjiang N, Abulimiti B, Ling F, Xiang M, Deng X, Wei J, Zhang B. Intersystem Crossing of 2-Methlypyrazine Studied by Femtosecond Photoelectron Imaging. Molecules 2022; 27:6245. [PMID: 36234780 PMCID: PMC9572115 DOI: 10.3390/molecules27196245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Revised: 09/16/2022] [Accepted: 09/18/2022] [Indexed: 11/16/2022] Open
Abstract
2-methylpyrazine was excited to the high vibrational dynamics of the S1 state with 260 nm femtosecond laser light, and the evolution of the excited state was probed with 400 nm light. Because it was unstable, the S1 state decayed via intersystem crossing to the triplet state T1, and it may have decayed to the ground state S0 via internal conversion. S1-to-T1 intersystem crossing was observed by combining time-resolved mass spectrometry and time-resolved photoelectron spectroscopy. The crossover time scale was 23 ps. Rydberg states were identified, and the photoelectron spectral and angular distributions indicated accidental resonances of the S1 and T1 states with the 3s and 3p Rydberg states, respectively, during ionization.
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Affiliation(s)
- Naipisai Wumaierjiang
- Xinjiang Key Laboratory for Luminescence Minerals and Optical Functional Materials, School of Physics and Electronic Engineering, Xinjiang Normal University, Urumqi 830054, China
| | - Bumaliya Abulimiti
- Xinjiang Key Laboratory for Luminescence Minerals and Optical Functional Materials, School of Physics and Electronic Engineering, Xinjiang Normal University, Urumqi 830054, China
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Fengzi Ling
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Mei Xiang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Xulan Deng
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Jie Wei
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Bing Zhang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China
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2
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Lacinbala O, Féraud G, Vincent J, Pino T. Aromatic and Acetylenic C-H or C-D Stretching Bands Anharmonicity Detection of Phenylacetylene by UV Laser-Induced Vibrational Emission. J Phys Chem A 2022; 126:4891-4901. [PMID: 35880827 DOI: 10.1021/acs.jpca.2c01436] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The anharmonic infrared (IR) emission spectra of phenylacetylene C6H5CCH and an isotopologue C6H5CCD induced by 193 nm UV excitation have been investigated in the gas phase. The study has been operated with a homemade IR spectrometer enabling to record time- and wavelength-resolved spectra between 2.5 and 4.5 μm, emitted all along the collisional cooling. The analysis is supported by a kinetic Monte Carlo simulation in the vibrational harmonic approximation. For both species, the anharmonic shifts of the acetylenic C-H or C-D stretching modes and the aromatic C-H stretching modes are studied for band positions and bandwidths in terms of the internal energy. For C6H5CCD, the internal energy dependence of the emission intensity band ratio is investigated and rationalized. This work demonstrates the potential of time-resolved IR emission spectroscopy to explore anharmonicity of astrophysically relevant molecules.
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Affiliation(s)
- Ozan Lacinbala
- Institut des Sciences Moléculaires d'Orsay (ISMO), Université Paris-Saclay, CNRS, 91405 Orsay, France
| | - Géraldine Féraud
- CNRS, LERMA, Sorbonne Université, Observatoire de Paris, Université PSL, F-75005, Paris, France
| | - Julien Vincent
- Institut des Sciences Moléculaires d'Orsay (ISMO), Université Paris-Saclay, CNRS, 91405 Orsay, France
| | - Thomas Pino
- Institut des Sciences Moléculaires d'Orsay (ISMO), Université Paris-Saclay, CNRS, 91405 Orsay, France
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3
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Abstract
Photochemical reactions are increasingly being used for chemical and materials synthesis, for example, in photoredox catalysis, and generally involve photoexcitation of molecular chromophores dissolved in a liquid solvent. The choice of solvent influences the outcomes of the photochemistry because solute-solvent interactions modify the energies of and crossings between electronic states of the chromophores, and they affect the evolving structures of the photoexcited molecules. Ultrafast laser spectroscopy methods with femtosecond to picosecond time resolution can resolve the dynamics of these photoexcited molecules as they undergo structural and electronic changes, relax back to the ground state, dissipate their excess internal energy to the surrounding solvent, or undergo photochemical reactions. In this Account, we illustrate how experimental studies using ultrafast lasers can reveal the influences that different solvents or cosolutes exert on the photoinduced nonadiabatic dynamics of internal conversion and intersystem crossing in nonradiative relaxation pathways. Although the environment surrounding a solute molecule is rapidly changing, with fluctuations in the coordination to neighboring solvent molecules occurring on femtosecond or picosecond time scales, we show that it is possible to photoexcite selectively only those molecular chromophores transiently experiencing specific solute-solvent interactions such as intermolecular hydrogen bonding.The effects of different solvation environments on the photodynamics are illustrated using four selected examples of photochemical processes in which the solvent has a marked effect on the outcomes. We first consider two aromatic carbonyl compounds, benzophenone and acetophenone, which are known to undergo fast intersystem crossing to populate the first excited triplet state on time scales of a few picoseconds. We show that the nonadiabatic excited-state dynamics are modified by transient hydrogen bonding of the carbonyl group to a protic solvent or by coordination to a metal cation cosolute. We then examine how different solvents modify the competition between two alternative relaxation pathways in a photoexcited UVA-sunscreen molecule, diethylamino hydroxybenzoyl hexyl benzoate (DHHB). This relaxation back to the ground electronic state is an essential part of the effective operation of the sunscreen compound, but the dynamics are sensitive to the surrounding environment. Finally, we consider how solvents of different polarity affect the energies and lifetimes of excited states with locally excited or charge-transfer character in heterocyclic organic compounds used as excited-state electron donors for photoredox catalysis. With these and other examples, we seek to develop a molecular level understanding of how the choice of solution environment might be used to control the outcomes of photochemical reactions.
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Affiliation(s)
- Ravi Kumar Venkatraman
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, United Kingdom
| | - Andrew J. Orr-Ewing
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, United Kingdom
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4
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Robertson PA, Bishop HM, Orr-Ewing AJ. Tuning the Excited-State Dynamics of Acetophenone Using Metal Ions in Solution. J Phys Chem Lett 2021; 12:5473-5478. [PMID: 34085833 DOI: 10.1021/acs.jpclett.1c01466] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The effects of dissolved metal salts on the excited-state dynamics of acetophenone in solution have been explored by using ultrafast transient absorption spectroscopy at two UV excitation wavelengths. In the absence of metal ions, the S1(nπ*) transition of acetophenone is excited at 320 nm, with intersystem crossing (ISC) occurring with a time constant τISC = 5.95 ± 0.47 ps in acetonitrile solution. Excitation at 280 nm accesses the S2(ππ*) state, which internally converts (<0.2 ps) to S1 before undergoing ISC with τISC = 4.36 ± 0.14 ps. Coordination to Mg2+ ions makes the S2 state accessible to excitation at 320 nm, with the rate of S2 → S1 internal conversion reducing 3-fold but the ISC rate increasing. These changes to the excited-state energies and dynamics of this model photosensitizer indicate that dissolved metal salts could modify the photochemistry of synthetically useful homogeneous photocatalytic systems.
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Affiliation(s)
- Patrick A Robertson
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Hannah M Bishop
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Andrew J Orr-Ewing
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
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5
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Kotsina N, Townsend D. Improved insights in time-resolved photoelectron imaging. Phys Chem Chem Phys 2021; 23:10736-10755. [DOI: 10.1039/d1cp00933h] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We review new light source developments and data analysis considerations relevant to the time-resolved photoelectron imaging technique. Case studies illustrate how these themes may enhance understanding in studies of excited state molecular dynamics.
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Affiliation(s)
- Nikoleta Kotsina
- Institute of Photonics & Quantum Sciences
- Heriot-Watt University
- Edinburgh
- UK
| | - Dave Townsend
- Institute of Photonics & Quantum Sciences
- Heriot-Watt University
- Edinburgh
- UK
- Institute of Chemical Sciences
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6
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Li S, Liu L, Deng Y, Huang Y, Chen Y, Liao B. Terminal anion induced zinc(II) mononuclear complexes trans-to-cis isomerization regulate photoluminescence properties and its solution behavior. Polyhedron 2019. [DOI: 10.1016/j.poly.2019.114158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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7
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Holt EL, Stavros VG. Applications of ultrafast spectroscopy to sunscreen development, from first principles to complex mixtures. INT REV PHYS CHEM 2019. [DOI: 10.1080/0144235x.2019.1663062] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Emily L. Holt
- Molecular Analytical Science Centre for Doctoral Training, Senate House, University of Warwick, Coventry, UK
- Department of Chemistry, University of Warwick, Coventry, UK
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8
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Röder A, Petersen J, Issler K, Fischer I, Mitrić R, Poisson L. Exploring the Excited-State Dynamics of Hydrocarbon Radicals, Biradicals, and Carbenes Using Time-Resolved Photoelectron Spectroscopy and Field-Induced Surface Hopping Simulations. J Phys Chem A 2019; 123:10643-10662. [DOI: 10.1021/acs.jpca.9b06346] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Anja Röder
- Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
- LIDYL, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France
| | - Jens Petersen
- Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Kevin Issler
- Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Ingo Fischer
- Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Roland Mitrić
- Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Lionel Poisson
- LIDYL, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France
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9
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Kotsina N, Belli F, Gao SF, Wang YY, Wang P, Travers JC, Townsend D. Ultrafast Molecular Spectroscopy Using a Hollow-Core Photonic Crystal Fiber Light Source. J Phys Chem Lett 2019; 10:715-720. [PMID: 30694062 DOI: 10.1021/acs.jpclett.8b03777] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We demonstrate, for the first time, the application of rare-gas-filled hollow-core photonic crystal fibers (HC-PCFs) as tunable ultraviolet light sources in femtosecond pump-probe spectroscopy. A critical requirement here is excellent output stability over extended periods of data acquisition, and we show this can be readily achieved. The time-resolved photoelectron imaging technique reveals nonadiabatic dynamical processes operating on three distinct time scales in the styrene molecule following excitation over the 242-258 nm region. These include ultrafast (<100 fs) internal conversion between the S2(ππ*) and S1(ππ*) electronic states and subsequent intramolecular vibrational energy redistribution within S1(ππ*). Compact, cost-effective, and highly efficient benchtop HC-PCF sources have huge potential to open up many exciting new avenues for ultrafast spectroscopy in the ultraviolet and vacuum ultraviolet spectral regions. We anticipate that our initial validation of this approach will generate important impetus in this area.
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Affiliation(s)
- Nikoleta Kotsina
- Institute of Photonics & Quantum Sciences , Heriot-Watt University , Edinburgh EH14 4AS , U.K
| | - Federico Belli
- Institute of Photonics & Quantum Sciences , Heriot-Watt University , Edinburgh EH14 4AS , U.K
| | - Shou-Fei Gao
- Beijing Engineering Research Centre of Laser Technology, Institute of Laser Engineering , Beijing University of Technology , 100124 Beijing , China
| | - Ying-Ying Wang
- Beijing Engineering Research Centre of Laser Technology, Institute of Laser Engineering , Beijing University of Technology , 100124 Beijing , China
| | - Pu Wang
- Beijing Engineering Research Centre of Laser Technology, Institute of Laser Engineering , Beijing University of Technology , 100124 Beijing , China
| | - John C Travers
- Institute of Photonics & Quantum Sciences , Heriot-Watt University , Edinburgh EH14 4AS , U.K
| | - Dave Townsend
- Institute of Photonics & Quantum Sciences , Heriot-Watt University , Edinburgh EH14 4AS , U.K
- Institute of Chemical Sciences , Heriot-Watt University , Edinburgh EH14 4AS , U.K
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10
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Dyakov YA, Toliautas S, Trakhtenberg LI, Valkunas L. Excited state photodissociation dynamics of 2-, 3-, 4-hydroxyacetophenone: Theoretical study. Chem Phys 2018. [DOI: 10.1016/j.chemphys.2018.07.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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11
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Coates MR, Larsen MAB, Forbes R, Neville SP, Boguslavskiy AE, Wilkinson I, Sølling TI, Lausten R, Stolow A, Schuurman MS. Vacuum ultraviolet excited state dynamics of the smallest ring, cyclopropane. II. Time-resolved photoelectron spectroscopy andab initiodynamics. J Chem Phys 2018; 149:144311. [DOI: 10.1063/1.5044402] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Michael R. Coates
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie Drive, Ottawa, Ontario K1N 6N5, Canada
| | - Martin A. B. Larsen
- Department of Chemistry, University of Copenhagen, 2100 Copenhagen Ø, Denmark
| | - Ruaridh Forbes
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
- Department of Physics, University of Ottawa, 25 Templeton Street, Ottawa, Ontario K1N 6N5, Canada
| | - Simon P. Neville
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie Drive, Ottawa, Ontario K1N 6N5, Canada
| | - Andrey E. Boguslavskiy
- Department of Physics, University of Ottawa, 25 Templeton Street, Ottawa, Ontario K1N 6N5, Canada
- National Research Council of Canada, 100 Sussex Dr., Ottawa, Ontario K1A 0R6, Canada
| | - Iain Wilkinson
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH Hahn-Meitner-Platz 1, D-14109 Berlin, Germany
| | - Theis I. Sølling
- Department of Chemistry, University of Copenhagen, 2100 Copenhagen Ø, Denmark
| | - Rune Lausten
- National Research Council of Canada, 100 Sussex Dr., Ottawa, Ontario K1A 0R6, Canada
| | - Albert Stolow
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie Drive, Ottawa, Ontario K1N 6N5, Canada
- Department of Physics, University of Ottawa, 25 Templeton Street, Ottawa, Ontario K1N 6N5, Canada
- National Research Council of Canada, 100 Sussex Dr., Ottawa, Ontario K1A 0R6, Canada
| | - Michael S. Schuurman
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie Drive, Ottawa, Ontario K1N 6N5, Canada
- National Research Council of Canada, 100 Sussex Dr., Ottawa, Ontario K1A 0R6, Canada
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12
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Boguslavskiy AE, Schalk O, Gador N, Glover WJ, Mori T, Schultz T, Schuurman MS, Martínez TJ, Stolow A. Excited state non-adiabatic dynamics of the smallest polyene, trans 1,3-butadiene. I. Time-resolved photoelectron-photoion coincidence spectroscopy. J Chem Phys 2018; 148:164302. [DOI: 10.1063/1.5016452] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Affiliation(s)
- Andrey E. Boguslavskiy
- National Research Council Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada
- Department of Chemistry, University of Ottawa, Ottawa, Ontario K1A 0R6, Canada
| | - Oliver Schalk
- National Research Council Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada
| | - Niklas Gador
- National Research Council Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada
| | - William J. Glover
- Department of Chemistry and PULSE Institute, Stanford University, Stanford, California 94305, USA
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Toshifumi Mori
- Department of Chemistry and PULSE Institute, Stanford University, Stanford, California 94305, USA
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Thomas Schultz
- Ulsan National Institute of Science and Technology, Ulju-gun, Ulsan 44919, South Korea
| | - Michael S. Schuurman
- National Research Council Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada
- Department of Chemistry, University of Ottawa, Ottawa, Ontario K1A 0R6, Canada
| | - Todd J. Martínez
- Department of Chemistry and PULSE Institute, Stanford University, Stanford, California 94305, USA
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Albert Stolow
- National Research Council Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada
- Department of Chemistry, University of Ottawa, Ottawa, Ontario K1A 0R6, Canada
- Department of Physics, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
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13
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Roy A, Seidel R, Kumar G, Bradforth SE. Exploring Redox Properties of Aromatic Amino Acids in Water: Contrasting Single Photon vs Resonant Multiphoton Ionization in Aqueous Solutions. J Phys Chem B 2018. [DOI: 10.1021/acs.jpcb.7b11762] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Anirban Roy
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, United States
| | - Robert Seidel
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, United States
- Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489 Berlin, Germany
| | - Gaurav Kumar
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, United States
| | - Stephen E. Bradforth
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, United States
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14
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Abstract
Despite the pivotal role of ultraviolet (UV) radiation in sustaining life on Earth, overexposure to this type of radiation can have catastrophic effects, such as skin cancer. Sunscreens, the most common form of artificial protection against such harmful effects, absorb UV radiation before it reaches vulnerable skin cells. Absorption of UV radiation prompts ultrafast molecular events in sunscreen molecules which, ideally, would allow for fast and safe dissipation of the excess energy. However, our knowledge of these mechanisms remains limited. In this article, we will review recent advances in the field of ultrafast photodynamics (light induced molecular processes occurring within femtoseconds, fs, 10-15 s to picoseconds, ps, 10-12 s) of sunscreens. We follow a bottom-up approach to common sunscreen active ingredients, analysing any emerging trends from the current literature on the subject. Moreover, we will identify the main questions that remain unanswered, pinpoint some of the main challenges and finally comment on the outlook of this exciting field of research.
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15
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Hao Q, Deng X, Long J, Wang Y, Abulimiti B, Zhang B. Real-time observation of cascaded electronic relaxation processes in p-Fluorotoluene. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2017; 183:109-115. [PMID: 28441538 DOI: 10.1016/j.saa.2017.04.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 03/31/2017] [Accepted: 04/17/2017] [Indexed: 06/07/2023]
Abstract
Ultrafast electronic relaxation processes following two photoexcitation of 400nm in p-Fluorotoluene (pFT) have been investigated utilizing time-resolved photoelectron imaging coupled with time-resolved mass spectroscopy. Cascaded electronic relaxation processes started from the electronically excited S2 state are directly imaged in real time and well characterized by two distinct time constants of ~85±10fs and 2.4±0.3ps. The rapid component corresponds to the lifetime of the initially excited S2 state, including the structure relaxation from the Franck-Condon region to the conical intersection of S2/S1 and the subsequent internal conversion to the highly excited S1 state. While, the slower relaxation constant is attributed to the further internal conversion to the high levels of S0 from the secondarily populated S1 locating in the channel three region. Moreover, dynamical differences with benzene and toluene of analogous structures, including, specifically, the slightly slower relaxation rate of S2 and the evidently faster decay of S1, are also presented and tentatively interpreted as the substituent effects. In addition, photoelectron kinetic energy and angular distributions reveal the feature of accidental resonances with low-lying Rydberg states (the 3p, 4s and 4p states) during the multi-photon ionization process, providing totally unexpected but very interesting information for pFT.
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Affiliation(s)
- Qiaoli Hao
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Xulan Deng
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Jinyou Long
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Yanmei Wang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Bumaliya Abulimiti
- College of Physics and Electronic Engineering, Xinjiang Normal University, Urumqi 830054, PR China.
| | - Bing Zhang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
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16
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Crane SW, Zawadzki MM, Thompson JOF, Kotsina N, Ghafur O, Townsend D. Caveats in the interpretation of time-resolved photoionization measurements: A photoelectron imaging study of pyrrole. J Chem Phys 2016; 145:234304. [DOI: 10.1063/1.4972096] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Stuart W. Crane
- Institute of Photonics and Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Magdalena M. Zawadzki
- Institute of Photonics and Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - James O. F. Thompson
- Institute of Photonics and Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Nikoleta Kotsina
- Institute of Photonics and Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Omair Ghafur
- Institute of Photonics and Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Dave Townsend
- Institute of Photonics and Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
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17
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Neville SP, Wang Y, Boguslavskiy AE, Stolow A, Schuurman MS. Substituent effects on dynamics at conical intersections: Allene and methyl allenes. J Chem Phys 2016; 144:014305. [DOI: 10.1063/1.4938561] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Simon P. Neville
- Department of Chemistry, University of Ottawa, 10 Marie Curie, Ottawa, Ontario K1N 6N5, Canada
| | - Yanmei Wang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, People’s Republic of China
| | - Andrey E. Boguslavskiy
- Department of Chemistry, University of Ottawa, 10 Marie Curie, Ottawa, Ontario K1N 6N5, Canada
- National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada
- Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa ON K1N 6N5, Canada
| | - Albert Stolow
- Department of Chemistry, University of Ottawa, 10 Marie Curie, Ottawa, Ontario K1N 6N5, Canada
- National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada
- Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa ON K1N 6N5, Canada
| | - Michael S. Schuurman
- Department of Chemistry, University of Ottawa, 10 Marie Curie, Ottawa, Ontario K1N 6N5, Canada
- National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada
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18
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19
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Féraud G, Pino T, Falvo C, Parneix P, Combriat T, Bréchignac P. Intramolecular Processes Revealed Using UV-Laser-Induced IR-Fluorescence: A New Perspective on the "Channel Three" of Benzene. J Phys Chem Lett 2014; 5:1083-1090. [PMID: 26274453 DOI: 10.1021/jz402697u] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Radiative relaxation in the infrared (IR) is common following nonradiative electronic relaxation processes, but it is rarely measured. We present ultraviolet laser-induced infrared fluorescence (UV-LIIRF) excitation spectroscopy and dispersed UV-LIIRF spectroscopy of gas phase benzene vibronically excited around the onset of channel 3, using a homemade spectrometer. We found that the vibrational IR fluorescence yield is clearly higher when benzene is excited above the onset than when it is excited below. Significant changes in dispersed IR emission profiles resulting from excitations below and above the onset of channel 3 were also observed. These results suggest that isomerization of benzene toward fulvene occurs efficiently below the opening of channel 3 and confirm that channel 3 involves a photophysical relaxation pathway that efficiently competes with isomerization.
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Affiliation(s)
- G Féraud
- Institut des Sciences Moléculaires d'Orsay, CNRS, Univ Paris-Sud, 91405 Orsay Cedex, France
| | - T Pino
- Institut des Sciences Moléculaires d'Orsay, CNRS, Univ Paris-Sud, 91405 Orsay Cedex, France
| | - C Falvo
- Institut des Sciences Moléculaires d'Orsay, CNRS, Univ Paris-Sud, 91405 Orsay Cedex, France
| | - P Parneix
- Institut des Sciences Moléculaires d'Orsay, CNRS, Univ Paris-Sud, 91405 Orsay Cedex, France
| | - T Combriat
- Institut des Sciences Moléculaires d'Orsay, CNRS, Univ Paris-Sud, 91405 Orsay Cedex, France
| | - Ph Bréchignac
- Institut des Sciences Moléculaires d'Orsay, CNRS, Univ Paris-Sud, 91405 Orsay Cedex, France
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20
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Yuan B, Yu Z, Bernstein ER. Initial decomposition mechanism for the energy release from electronically excited energetic materials: FOX-7 (1,1-diamino-2,2-dinitroethene, C2H4N4O4). J Chem Phys 2014; 140:074708. [DOI: 10.1063/1.4865266] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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21
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Wolf TJA, Kuhlman TS, Schalk O, Martínez TJ, Møller KB, Stolow A, Unterreiner AN. Hexamethylcyclopentadiene: time-resolved photoelectron spectroscopy and ab initio multiple spawning simulations. Phys Chem Chem Phys 2014; 16:11770-9. [DOI: 10.1039/c4cp00977k] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Time-resolved photoelectron spectroscopy and ab initio multiple spawning dynamical simulations of hexamethylcyclopentadiene reveal wavepacket evolution in a distinct degree of freedom.
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Affiliation(s)
- T. J. A. Wolf
- Institut für Physikalische Chemie and Center for Functional Nanostructures (CFN)
- Karlsruhe Institute of Technology (KIT)
- 76131 Karlsruhe, Germany
- Stanford PULSE Institute
- Menlo Park, USA
| | - T. S. Kuhlman
- Department of Chemistry
- Technical University of Denmark
- DK-2800 Kgs. Lyngby, Denmark
| | - O. Schalk
- Stockholm University
- AlbaNova University Center
- , Sweden
- National Research Council
- , Canada
| | - T. J. Martínez
- Stanford PULSE Institute
- Menlo Park, USA
- Department of Chemistry
- Stanford University
- Stanford, USA
| | - K. B. Møller
- Department of Chemistry
- Technical University of Denmark
- DK-2800 Kgs. Lyngby, Denmark
| | - A. Stolow
- National Research Council
- , Canada
- Department of Chemistry
- University of Ottawa
- Canada
| | - A.-N. Unterreiner
- Institut für Physikalische Chemie and Center for Functional Nanostructures (CFN)
- Karlsruhe Institute of Technology (KIT)
- 76131 Karlsruhe, Germany
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22
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Corrales ME, Loriot V, Balerdi G, González-Vázquez J, de Nalda R, Bañares L, Zewail AH. Structural dynamics effects on the ultrafast chemical bond cleavage of a photodissociation reaction. Phys Chem Chem Phys 2014; 16:8812-8. [DOI: 10.1039/c3cp54677b] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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23
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Cui G, Lu Y, Thiel W. Electronic excitation energies, three-state intersections, and photodissociation mechanisms of benzaldehyde and acetophenone. Chem Phys Lett 2012. [DOI: 10.1016/j.cplett.2012.04.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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24
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Suzuki T. Time-resolved photoelectron spectroscopy of non-adiabatic electronic dynamics in gas and liquid phases. INT REV PHYS CHEM 2012. [DOI: 10.1080/0144235x.2012.699346] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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25
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Suzuki YI, Horio T, Fuji T, Suzuki T. Time-resolved photoelectron imaging of S2 → S1 internal conversion in benzene and toluene. J Chem Phys 2011; 134:184313. [PMID: 21568512 DOI: 10.1063/1.3586809] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Ultrafast internal conversion of benzene and toluene from the S(2) states was studied by time-resolved photoelectron imaging with a time resolution of 22 fs. Time-energy maps of the photoelectron intensity and the angular anisotropy were generated from a series of photoelectron images. The photoelectron kinetic energy distribution exhibits a rapid energy shift and intensity revival, which indicates nuclear motion on the S(2) adiabatic surface, while the ultrafast evolution of the angular anisotropy revealed a change in the electronic character of the S(2) adiabatic surface. From their decay profiles of the total photoelectron intensity, the time constants of 48 ± 4 and 62 ± 4 fs were determined for the population decay from the S(2) states in benzene and toluene, respectively.
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Affiliation(s)
- Yoshi-Ichi Suzuki
- Japan Science and Technology Agency, CREST, Sanbancho, Chiyoda-ku, Tokyo, Japan
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26
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Dachraoui H, Michelswirth M, Siffalovic P, Bartz P, Schäfer C, Schnatwinkel B, Mattay J, Pfeiffer W, Drescher M, Heinzmann U. Photoinduced reconfiguration cycle in a molecular adsorbate layer studied by femtosecond inner-shell photoelectron spectroscopy. PHYSICAL REVIEW LETTERS 2011; 106:107401. [PMID: 21469832 DOI: 10.1103/physrevlett.106.107401] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Indexed: 05/30/2023]
Abstract
A time-resolved study of core-level chemical shifts in a monolayer of aromatic molecules reveals complex photoinduced reaction dynamics. The combination of electron spectroscopy for chemical analysis and ultrashort pulse excitation in the extreme ultraviolet allows performing time-correlated 4d-core-level spectroscopy of iodine atoms that probe the local chemical environment in the adsorbate molecule. The selectivity of the method unveils metastable molecular configurations that appear about 50 ps after the excitation and are efficiently quenched back to the ground state.
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Affiliation(s)
- H Dachraoui
- Molekül und Oberflächenphysik, Fakultät für Physik, Universität Bielefeld, Universitätsstraße 25, 33615 Bielefeld, Germany
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27
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Brogaard RY, Boguslavskiy AE, Schalk O, Enright GD, Hopf H, Raev VA, Jones PG, Thomsen DL, Sølling TI, Stolow A. Pseudo-Bimolecular [2+2] Cycloaddition Studied by Time-Resolved Photoelectron Spectroscopy. Chemistry 2011; 17:3922-31. [DOI: 10.1002/chem.201002928] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Indexed: 11/07/2022]
Affiliation(s)
- Rasmus Y Brogaard
- Steacie Institute for Molecular Sciences, National Research Council (Canada), Ottawa, ON, Canada
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28
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Lecointre J, Roberts GM, Horke DA, Verlet JRR. Ultrafast relaxation dynamics observed through time-resolved photoelectron angular distributions. J Phys Chem A 2011; 114:11216-24. [PMID: 20961158 DOI: 10.1021/jp1028855] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Time-resolved photoelectron imaging of the 7,7,8,8-tetracyanoquinodimethane (TCNQ) radical anion is presented. Photoelectron angular distributions (PADs) are qualitatively analyzed in terms of the simple s-p model that is based on symmetry arguments. The internal conversion dynamics from the first excited state (1(2)B(3u)) to the ground state ((2)B(2g)) may be observed through temporal changes in the PADs of the spectrally overlapping photoelectron features arising from photodetachment of the ground state and the excited state. A formulism for extracting the population dynamics from the β(2) anisotropy parameter of overlapping spectroscopic features is presented. This is used to extract the lifetime of the first excited state, which is in good agreement with that observed in the time-resolved photoelectron spectra.
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Affiliation(s)
- Julien Lecointre
- Department of Chemistry, University of Durham, South Road, Durham, DH1 3LE, UK
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29
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Scarborough TD, Strohaber J, Foote DB, McAcy CJ, Uiterwaal CJGJ. Ultrafast REMPI in benzene and the monohalobenzenes without the focal volume effect. Phys Chem Chem Phys 2011; 13:13783-90. [DOI: 10.1039/c1cp20876d] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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30
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Stolow A. Time-resolved photoelectron spectroscopy: Non-adiabatic dynamics in polyatomic molecules. INT REV PHYS CHEM 2010. [DOI: 10.1080/0144235031000092448] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Albert Stolow
- a Steacie Institute for Molecular Sciences , National Research Council of Canada , 100 Sussex Drive, Ottawa , Ontario , K1A 0R6 , Canada
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31
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Wang B, Liu B, Wang Y, Wang L. Dynamics of Highly Excited Nitroaromatics. J Phys Chem A 2010; 114:12972-8. [DOI: 10.1021/jp104727p] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Bingxing Wang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Dalian 116023, China
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32
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Schalk O, Boguslavskiy AE, Stolow A. Substituent Effects on Dynamics at Conical Intersections: Cyclopentadienes. J Phys Chem A 2010; 114:4058-64. [DOI: 10.1021/jp911286s] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Oliver Schalk
- Steacie Institute for Molecular Sciences, National Research Council, Ottawa, Ontario K1A 0R6, Canada
| | - Andrey E. Boguslavskiy
- Steacie Institute for Molecular Sciences, National Research Council, Ottawa, Ontario K1A 0R6, Canada
| | - Albert Stolow
- Steacie Institute for Molecular Sciences, National Research Council, Ottawa, Ontario K1A 0R6, Canada
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33
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Nunn ADG, Minns RS, Spesyvtsev R, Bearpark MJ, Robb MA, Fielding HH. Ultrafast dynamics through conical intersections and intramolecular vibrational energy redistribution in styrene. Phys Chem Chem Phys 2010; 12:15751-9. [DOI: 10.1039/c0cp01723j] [Citation(s) in RCA: 20] [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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34
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Liu BK, Wang BX, Wang YQ, Wang L. Wavelength-dependent Photodissociation Dynamics of Benzaldehyde. CHINESE J CHEM PHYS 2009. [DOI: 10.1088/1674-0068/22/06/587-591] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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35
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Noller B, Poisson L, Fischer I, Mestdagh JM. Side-Chain Effects on the Electronic Relaxation of Radicals followed by Time-Resolved Pump−Probe Spectroscopy: 2,3-Dimethylbut-2-yl vs tert-Butyl. J Phys Chem A 2009; 114:3045-9. [DOI: 10.1021/jp9062059] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Bastian Noller
- Laboratoire Francis Perrin, CNRS URA 2453, CEA IRAMIS/Service des Photos, Atoms et Molécules, F-91191 Gif-sur-Yvette Cedex, France, and Institute of Physical Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Lionel Poisson
- Laboratoire Francis Perrin, CNRS URA 2453, CEA IRAMIS/Service des Photos, Atoms et Molécules, F-91191 Gif-sur-Yvette Cedex, France, and Institute of Physical Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Ingo Fischer
- Laboratoire Francis Perrin, CNRS URA 2453, CEA IRAMIS/Service des Photos, Atoms et Molécules, F-91191 Gif-sur-Yvette Cedex, France, and Institute of Physical Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Jean-Michel Mestdagh
- Laboratoire Francis Perrin, CNRS URA 2453, CEA IRAMIS/Service des Photos, Atoms et Molécules, F-91191 Gif-sur-Yvette Cedex, France, and Institute of Physical Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
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36
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Montero R, Castaño F, Martínez R, Longarte A. Relaxation Dynamics of Naphthalene and 1-Aminonaphthalene in Superexcited States. J Phys Chem A 2009; 113:952-8. [DOI: 10.1021/jp8056064] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Raúl Montero
- Departamento de Química-Física, Facultad de Ciencia y Tecnología, Universidad del País Vasco. Apart. 644, 48080 Bilbao, Spain
| | - Fernando Castaño
- Departamento de Química-Física, Facultad de Ciencia y Tecnología, Universidad del País Vasco. Apart. 644, 48080 Bilbao, Spain
| | - Roberto Martínez
- Departamento de Química-Física, Facultad de Ciencia y Tecnología, Universidad del País Vasco. Apart. 644, 48080 Bilbao, Spain
| | - Asier Longarte
- Departamento de Química-Física, Facultad de Ciencia y Tecnología, Universidad del País Vasco. Apart. 644, 48080 Bilbao, Spain
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37
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Alata I, Omidyan R, Dedonder-Lardeux C, Broquier M, Jouvet C. Electronically excited states of protonated aromatic molecules: benzaldehyde. Phys Chem Chem Phys 2009; 11:11479-86. [DOI: 10.1039/b913422k] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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38
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Oladepo SA, Loppnow GR. Ultraviolet resonance Raman spectroscopy as a robust spectroscopic tool for in situ sunscreen analysis. Anal Chim Acta 2008. [DOI: 10.1016/j.aca.2008.08.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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39
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Stolow A, Underwood JG. Time-Resolved Photoelectron Spectroscopy of Nonadiabatic Dynamics in Polyatomic Molecules. ADVANCES IN CHEMICAL PHYSICS 2008. [DOI: 10.1002/9780470259498.ch6] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
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40
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Pino T, Douin S, Boudin N, Bréchignac P. Gas-Phase Electronic Spectra of Two Substituted Benzene Cations: Phenylacetylene+ and 4-Fluorostyrene+. J Phys Chem A 2007; 111:13358-64. [DOI: 10.1021/jp073381c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- T. Pino
- Laboratoire de Photophysique Moléculaire, CNRS, bâtiment 210 Université Paris-Sud, F-91405 Orsay Cedex, France
| | - S. Douin
- Laboratoire de Photophysique Moléculaire, CNRS, bâtiment 210 Université Paris-Sud, F-91405 Orsay Cedex, France
| | - N. Boudin
- Laboratoire de Photophysique Moléculaire, CNRS, bâtiment 210 Université Paris-Sud, F-91405 Orsay Cedex, France
| | - Ph. Bréchignac
- Laboratoire de Photophysique Moléculaire, CNRS, bâtiment 210 Université Paris-Sud, F-91405 Orsay Cedex, France
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41
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Resonance Raman spectroscopy and density functional theory study of the photodissociation dynamics of acetophenone in cyclohexane solution. Chem Phys Lett 2007. [DOI: 10.1016/j.cplett.2007.10.044] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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42
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Worth G, Carley R, Fielding H. Using photoelectron spectroscopy to unravel the excited-state dynamics of benzene. Chem Phys 2007. [DOI: 10.1016/j.chemphys.2007.03.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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43
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Ma C, Du Y, Kwok WM, Phillips DL. Femtosecond Transient Absorption and Nanosecond Time-Resolved Resonance Raman Study of the Solvent-Dependent Photo-Deprotection Reaction of Benzoin Diethyl Phosphate. Chemistry 2007; 13:2290-305. [PMID: 17154320 DOI: 10.1002/chem.200600893] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A combined femtosecond transient absorption (fs-TA) and nanosecond time-resolved resonance Raman (ns-TR3) study was performed to directly detect the dynamics and elucidate the mechanism of the excited state deactivation and solvent-dependent photo-deprotection pathways for benzoin diethyl phosphate (BDP) in neat acetonitrile (MeCN) and 75 % H2O/25 % MeCN. Comparison of the TA spectral evolution observed in the two solvents provides explicit evidence that the photophysical deactivation of the BDP singlet excited state has little solvent dependence. The TA spectra also indicate the related internal conversion (IC) and intersystem crossing (ISC) processes occur rapidly on hundreds of femtoseconds and approximately 2-3 ps time scales, respectively. From this and in conjunction with a photochemistry study and ground state resonance Raman (RR) measurements, the TA results reveal that the phenacyl localized BDP triplet state (that is mainly npi* nature) is the common and immediate precursor to the photo-deprotection reaction in both solvents. However, the triplet deprotection follows different pathways in neat MeCN versus the largely water containing solvent. The deprotection reaction in MeCN was determined to occur with a approximately 11 ns time constant and the reaction was found to be an unimolecular process leading to elimination of the diethyl phosphoric acid apparently concurrent with cyclization to yield the benzofuran product. In the water mixed solvent, the triplet reaction was observed to proceed with a approximately 15 ns time constant and the reaction leads to not only the deprotection-cyclization but also a heterolytic dissociation to release the diethyl phosphate anion through a branching and competing mechanism. The ns-TR3 spectra combined with relevant DFT calculations have been used to characterize the dynamics, structure and vibrational frequencies to help identify the important intermediates as well as to explore the reaction pathway leading to formation of the solvolysis product in the largely water solvent. A consecutive mechanism has been revealed for the heterolysis-solvolysis reaction in the water mixed solvent. The present work provides direct and irrevocable evidence for the dynamics and mechanistic description of the overall photophysics and deprotection related photochemistry for BDP.
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Affiliation(s)
- Chensheng Ma
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong S.A.R., PR China
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44
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Park ST, Feenstra JS, Zewail AH. Ultrafast electron diffraction: Excited state structures and chemistries of aromatic carbonyls. J Chem Phys 2006; 124:174707. [PMID: 16689590 DOI: 10.1063/1.2194017] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The photophysics and photochemistry of molecules with complex electronic structures, such as aromatic carbonyls, involve dark structures of radiationless processes. With ultrafast electron diffraction (UED) of isolated molecular beams it is possible to determine these transient structures, and in this contribution we examine the nature of structural dynamics in two systems, benzaldehyde and acetophenone. Both molecules are seen to undergo a bifurcation upon excitation (S(2)). Following femtosecond conversion to S(1), the bifurcation leads to the formation of molecular dissociation products, benzene and carbon monoxide for benzaldehyde, and benzoyl and methyl radicals for acetophenone, as well as intersystem crossing to the triplet state in both cases. The structure of the triplet state was determined to be "quinoidlike" of pipi(*) character with the excitation being localized in the phenyl ring. For the chemical channels, the product structures were also determined. The difference in photochemistry between the two species is discussed with respect to the change in large amplitude motion caused by the added methyl group in acetophenone. This discussion is also expanded to compare these results with the prototypical aliphatic carbonyl compounds, acetaldehyde and acetone. From these studies of structural dynamics, experimental and theoretical, we provide a landscape picture for, and the structures involved in, the radiationless pathways which determine the fate of molecules following excitation. For completeness, the UED methodology and the theoretical framework for structure determination are described in this full account of an earlier communication [J. S. Feenstra et al., J. Chem. Phys. 123, 221104 (2005)].
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Affiliation(s)
- Sang Tae Park
- Laboratory for Molecular Science, and Physical Biology Center for Ultrafast Science and Technology, California Institute of Technology, Pasadena, California 91125, USA
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45
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Feenstra JS, Park ST, Zewail AH. Excited state molecular structures and reactions directly determined by ultrafast electron diffraction. J Chem Phys 2005; 123:221104. [PMID: 16375461 DOI: 10.1063/1.2140700] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
In this communication, we report on the use of ultrafast electron diffraction to determine structural dynamics of excited states and reaction products of isolated aromatic carbonyls, acetophenone and benzaldehyde. For a 266 nm excitation, a bifurcation of pathways is structurally resolved, one leading to the formation of the triplet state (quinoid structure) and another to chemical products: for benzaldehyde the products are benzene and carbon monoxide (hydrogen migration and bond rupture) while those for acetophenone are the benzoyl and methyl radicals (bond rupture). The refined structures are compared with those predicted by theory. These dark structures and their radiationless transitions define the reduced energy landscape for complex reactions.
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Affiliation(s)
- Jonathan S Feenstra
- Laboratory for Molecular Science, Arthur Amos Noyes Laboratory for Chemical Physics, California Institute of Technology, Pasadena, CA 91125, USA
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46
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Fuß W, Schmid W, Trushin S. Ultrafast photochemistry of cyclopentadiene: Competing hydrogen migration and electrocyclic ring closure. Chem Phys 2005. [DOI: 10.1016/j.chemphys.2005.05.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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47
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Affiliation(s)
- Albert Stolow
- Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario, K1A 0R6 Canada.
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48
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Gessner O, Chrysostom ETH, Lee AMD, Wardlaw DM, Ho ML, Lee SJ, Cheng BM, Zgierski MZ, Chen IC, Shaffer JP, Hayden CC, Stolow A. Non-adiabatic intramolecular and photodissociation dynamics studied by femtosecond time-resolved photoelectron and coincidence imaging spectroscopy. Faraday Discuss 2004; 127:193-212. [PMID: 15471347 DOI: 10.1039/b316742a] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Time-resolved photoelectron spectroscopy (TRPES) is emerging as a useful tool for the study of non-adiabatic dynamics in isolated polyatomic molecules and clusters due to its sensitivity to both electronic and vibrational dynamics. A powerful extension of TRPES, coincidence imaging spectroscopy (CIS), based upon femtosecond time-resolved 3D momentum vector imaging of both photoions and photoelectrons in coincidence, is a new technique for the study of complex dissociative processes. Here we show how these spectroscopies can be used to study both non-adiabatic intramolecular and photodissociation dynamics in polyatomic molecules. Intramolecular dynamics in the alpha, beta-enones acrolein, crotonaldehyde and methyl vinyl ketone are studied using both TRPES and laser-induced fluorescence of HCO(X) product yields. The location of the methyl group is seen to have very dramatic effects on the relative electronic relaxation rates and the HCO(X) yield. Applying both TRPES and CIS to the 200 nm and 209 nm photodissociation of the nitric oxide dimer, (NO)2, we observe the fs time-scale evolution of the excited parent neutral via its photoelectron spectrum and the emergence of the NO(A) photofragment including its energy and angular distributions.
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Affiliation(s)
- O Gessner
- Steacie Institute for Molecular Sciences, National Research Council, Ottawa ON, Canada
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ter Steege DHA, Buma WJ. Spectroscopy and dynamics of excited states in maleimide and N-methyl maleimide: Ionic projection and ab initio calculations. J Chem Phys 2003. [DOI: 10.1063/1.1574803] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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