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Walmsley T, Unwin J, Allum F, Bari S, Boll R, Borne K, Brouard M, Bucksbaum P, Ekanayake N, Erk B, Forbes R, Howard AJ, Eng-Johnsson P, Lee JWL, Liu Z, Manschwetus B, Mason R, Passow C, Peschel J, Rivas D, Rolles D, Rörig A, Rouzée A, Vallance C, Ziaee F, Burt M. Characterizing the multi-dimensional reaction dynamics of dihalomethanes using XUV-induced Coulomb explosion imaging. J Chem Phys 2023; 159:144302. [PMID: 37823458 DOI: 10.1063/5.0172749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 09/27/2023] [Indexed: 10/13/2023] Open
Abstract
Site-selective probing of iodine 4d orbitals at 13.1 nm was used to characterize the photolysis of CH2I2 and CH2BrI initiated at 202.5 nm. Time-dependent fragment ion momenta were recorded using Coulomb explosion imaging mass spectrometry and used to determine the structural dynamics of the dissociating molecules. Correlations between these fragment momenta, as well as the onset times of electron transfer reactions between them, indicate that each molecule can undergo neutral three-body photolysis. For CH2I2, the structural evolution of the neutral molecule was simultaneously characterized along the C-I and I-C-I coordinates, demonstrating the sensitivity of these measurements to nuclear motion along multiple degrees of freedom.
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Affiliation(s)
- T Walmsley
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - J Unwin
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - F Allum
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - S Bari
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | - R Boll
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - K Borne
- J. R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506, USA
| | - M Brouard
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - P Bucksbaum
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - N Ekanayake
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | - B Erk
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | - R Forbes
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - A J Howard
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - P Eng-Johnsson
- Department of Physics, Lund University, 22100 Lund, Sweden
| | - J W L Lee
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | - Z Liu
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - B Manschwetus
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | - R Mason
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - C Passow
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | - J Peschel
- Department of Physics, Lund University, 22100 Lund, Sweden
| | - D Rivas
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - D Rolles
- J. R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506, USA
| | - A Rörig
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - A Rouzée
- Max-Born-Institute, Max-Born-Straße 2A, 12489 Berlin, Germany
| | - C Vallance
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - F Ziaee
- J. R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506, USA
| | - M Burt
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
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Campbell JS, Nauta K, Hansen CS, Kable SH. POPTARTS: A New Method to Determine Quantum Yields in a Molecular Beam. J Phys Chem A 2022; 126:9268-9275. [DOI: 10.1021/acs.jpca.2c06289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Affiliation(s)
- Jyoti S. Campbell
- School of Chemistry, University of New South Wales, Kensington, NSW2052, Australia
| | - Klaas Nauta
- School of Chemistry, University of New South Wales, Kensington, NSW2052, Australia
| | | | - Scott H. Kable
- School of Chemistry, University of New South Wales, Kensington, NSW2052, Australia
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Campbell JS, Nauta K, Kable SH, Hansen CS. Photodissociation dynamics of CF 3CHO: C-C bond cleavage. J Chem Phys 2021; 155:204303. [PMID: 34852470 DOI: 10.1063/5.0073974] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The photodissociation dynamics of jet-cooled trifluoroacetaldehyde (CF3CHO) into radical products, CF3 + HCO, was explored using velocity mapped ion imaging over the wavelength range 297.5 nm ≤λ≤ 342.8 nm (33 613-29 172 cm-1) covering the entire section of the absorption spectrum accessible with solar actinic wavelengths at the ground level. After initial excitation to the first excited singlet state, S1, the radical dissociation proceeds largely via the first excited triplet state, T1, at excitation energies above the T1 barrier. By combining velocity-mapped ion imaging with high-level theory, we place this barrier at 368.3 ± 2.4 kJ mol-1 (30 780 ± 200 cm-1). After exciting to S1 at energies below this barrier, the dissociation proceeds exclusively via the ground electronic state, S0. The dissociation threshold is determined to be 335.7 ± 1.8 kJ mol-1 (28 060 ± 150 cm-1). Using laser-induced fluorescence spectroscopy, the origin of the S1 ← S0 transition is assigned at 28 903 cm-1. The S0 dissociation channel is active at the S1 origin, but the yield significantly increases above 29 100 cm-1 due to enhanced intersystem crossing or internal conversion.
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Affiliation(s)
- Jyoti S Campbell
- School of Chemistry, University of New South Wales, Sydney, NSW, Australia
| | - Klaas Nauta
- School of Chemistry, University of New South Wales, Sydney, NSW, Australia
| | - Scott H Kable
- School of Chemistry, University of New South Wales, Sydney, NSW, Australia
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Hansen CS, Marchetti B, Karsili TNV, Ashfold MNR. Ultraviolet photodissociation of gas-phase transition metal complexes: dicarbonylcyclopentadienyliodoiron(II). Mol Phys 2021. [DOI: 10.1080/00268976.2020.1813343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Yifrach Y, Rahimi R, Portnov A, Bar I. A new imaging-based method for alignment of multiple laser beams. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2020; 237:118404. [PMID: 32361520 DOI: 10.1016/j.saa.2020.118404] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 04/20/2020] [Accepted: 04/20/2020] [Indexed: 06/11/2023]
Abstract
A new method for multiple laser beams alignment, useful in a wide range of spectroscopies, is proposed and demonstrated. The method, based on the coupling of spatial map imaging (SMI) with velocity map imaging (VMI), aided beams visualization, through interrogation of the ionization signal of different species in a time-of-flight mass spectrometer. This approach is very effective for alignment and for evaluating the spatial overlap of laser beams with a molecular beam. This was demonstrated by monitoring the resonant two-photon ionization spectrum of 2-phenylethylamine (PEA) monomer and its hydrated (PEA-H2O) cluster and the ionization-loss stimulated Raman spectrum of the cluster, via VMIs accumulation, as a function of the exciting laser wavelength. The former permitted immediate classification of the features in the spectrum, corresponding to the molecular ion or the cluster. The proposed methodology will be useful in other challenging multiple laser beam experiments for spectroscopic studies and is expected to improve extensively their outcome.
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Affiliation(s)
- Yair Yifrach
- Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Rami Rahimi
- Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Alexander Portnov
- Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Ilana Bar
- Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel.
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Chang Y, Yang J, Chen Z, Zhang Z, Yu Y, Li Q, He Z, Zhang W, Wu G, Ingle RA, Bain M, Ashfold MNR, Yuan K, Yang X, Hansen CS. Ultraviolet photochemistry of ethane: implications for the atmospheric chemistry of the gas giants. Chem Sci 2020; 11:5089-5097. [PMID: 34122966 PMCID: PMC8159213 DOI: 10.1039/d0sc01746a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 04/29/2020] [Indexed: 11/23/2022] Open
Abstract
Chemical processing in the stratospheres of the gas giants is driven by incident vacuum ultraviolet (VUV) light. Ethane is an important constituent in the atmospheres of the gas giants in our solar system. The present work describes translational spectroscopy studies of the VUV photochemistry of ethane using tuneable radiation in the wavelength range 112 ≤ λ ≤ 126 nm from a free electron laser and event-triggered, fast-framing, multi-mass imaging detection methods. Contributions from at least five primary photofragmentation pathways yielding CH2, CH3 and/or H atom products are demonstrated and interpreted in terms of unimolecular decay following rapid non-adiabatic coupling to the ground state potential energy surface. These data serve to highlight parallels with methane photochemistry and limitations in contemporary models of the photoinduced stratospheric chemistry of the gas giants. The work identifies additional photochemical reactions that require incorporation into next generation extraterrestrial atmospheric chemistry models which should help rationalise hitherto unexplained aspects of the atmospheric ethane/acetylene ratios revealed by the Cassini-Huygens fly-by of Jupiter.
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Affiliation(s)
- Yao Chang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences 457 Zhongshan Road Dalian 116023 China
| | - Jiayue Yang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences 457 Zhongshan Road Dalian 116023 China
| | - Zhichao Chen
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences 457 Zhongshan Road Dalian 116023 China
| | - Zhiguo Zhang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences 457 Zhongshan Road Dalian 116023 China
- Key Laboratory of Functional Materials and Devices for Informatics of Anhui Higher Education Institutions, School of Physics and Electronic Engineering, Fuyang Normal University Fuyang Anhui 236041 China
| | - Yong Yu
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences 457 Zhongshan Road Dalian 116023 China
| | - Qingming Li
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences 457 Zhongshan Road Dalian 116023 China
| | - Zhigang He
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences 457 Zhongshan Road Dalian 116023 China
| | - Weiqing Zhang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences 457 Zhongshan Road Dalian 116023 China
| | - Guorong Wu
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences 457 Zhongshan Road Dalian 116023 China
| | - Rebecca A Ingle
- Department of Chemistry, University College London London WC1H 0AJ UK
| | - Matthew Bain
- School of Chemistry, University of Bristol Bristol BS8 1TS UK
| | | | - Kaijun Yuan
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences 457 Zhongshan Road Dalian 116023 China
| | - Xueming Yang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences 457 Zhongshan Road Dalian 116023 China
- Department of Chemistry, Southern University of Science and Technology Shenzhen 518055 China
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Bain M, Hansen CS, Karsili TNV, Ashfold MNR. Quantifying rival bond fission probabilities following photoexcitation: C-S bond fission in t-butylmethylsulfide. Chem Sci 2019; 10:5290-5298. [PMID: 31191885 PMCID: PMC6540878 DOI: 10.1039/c9sc00738e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 04/23/2019] [Indexed: 11/21/2022] Open
Abstract
We illustrate a new, collision-free experimental strategy that allows determination of the absolute probabilities of rival bond fission processes in a photoexcited molecule - here t-butylmethylsulfide (BSM). The method combines single photon ('universal') ionization laser probe methods, simultaneous imaging of all probed fragments (multi-mass ion imaging) and the use of an appropriate internal calibrant (here dimethylsulfide). Image analysis allows quantification of the dynamics of the rival B-SM and BS-M bond fission processes following ultraviolet (UV) excitation of BSM and shows the former to be twice as probable, despite the only modest (∼2%) differences in the respective ground state equilibrium C-S bond lengths or bond strengths. Rationalising this finding should provide a stringent test of the two close-lying, coupled excited states of 1A'' symmetry accessed by UV excitation in BSM and related thioethers, of the respective transition dipole moment surfaces, and of the geometry dependent non-adiabatic couplings that enable the rival C-S bond fissions.
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Affiliation(s)
- Matthew Bain
- School of Chemistry , University of Bristol , Bristol , BS8 1TS , UK .
| | - Christopher S Hansen
- School of Chemistry , University of New South Wales , Sydney , NSW 2052 , Australia .
| | - Tolga N V Karsili
- Department of Chemistry , University of Louisiana at Lafayette , Louisiana , LA 70504 , USA
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8
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Vallance C. Multi-mass velocity-map imaging studies of photoinduced and electron-induced chemistry. Chem Commun (Camb) 2019; 55:6336-6352. [PMID: 31099379 DOI: 10.1039/c9cc02426c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Multi-mass velocity-map imaging (VMI) is becoming established as a promising method for probing the dynamics of a variety of gas-phase chemical processes. We provide an overview of velocity-map imaging and multi-mass velocity-map imaging techniques, highlighting examples in which these approaches have been used to provide mechanistic insights into a range of photoinduced and electron-induced chemical processes. Multi-mass detection capabilities have also led to the development of two new tools for the chemical dynamics toolbox, in the form of Coulomb-explosion imaging and covariance-map imaging. These allow details of molecular structure to be followed in real time over the course of a chemical reaction, offering the tantalising prospect of recording real-time 'molecular movies' of chemical dynamics. As these new methods become established within the reaction dynamics community, they promise new mechanistic insights into chemistry relevant to fields ranging from atmospheric chemistry and astrochemistry through to synthetic organic photochemistry and biology.
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Affiliation(s)
- Claire Vallance
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Rd, Oxford OX1 3TA, UK.
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Weeraratna C, Amarasinghe C, Lee SK, Li W, Suits AG. Demonstration of multi-hit and multi-mass capability of 3D imaging in a conventional velocity map imaging experiment. J Chem Phys 2018; 149:084202. [DOI: 10.1063/1.5040589] [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)
- Chaya Weeraratna
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, USA
| | | | - Suk Kyoung Lee
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA
| | - Wen Li
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA
| | - Arthur G. Suits
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, USA
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10
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Bain M, Hansen CS, Ashfold MNR. Communication: Multi-mass velocity map imaging study of the ultraviolet photodissociation of dimethyl sulfide using single photon ionization and a PImMS2 sensor. J Chem Phys 2018; 149:081103. [DOI: 10.1063/1.5048838] [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)
- Matthew Bain
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, United Kingdom
| | | | - Michael N. R. Ashfold
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, United Kingdom
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Ashfold MNR, Bain M, Hansen CS, Ingle RA, Karsili TNV, Marchetti B, Murdock D. Exploring the Dynamics of the Photoinduced Ring-Opening of Heterocyclic Molecules. J Phys Chem Lett 2017; 8:3440-3451. [PMID: 28661140 DOI: 10.1021/acs.jpclett.7b01219] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Excited states formed by electron promotion to an antibonding σ* orbital are now recognized as key to understanding the photofragmentation dynamics of a broad range of heteroatom containing small molecules: alcohols, thiols, amines, and many of their aromatic analogues. Such excited states may be populated by direct photoexcitation, or indirectly by nonadiabatic transfer of population from some other optically excited state (e.g., a ππ* state). This Perspective explores the extent to which the fast-growing literature pertaining to such (n/π)σ*-state mediated bond fissions can inform and enhance our mechanistic understanding of photoinduced ring-opening in heterocyclic molecules.
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Affiliation(s)
- Michael N R Ashfold
- School of Chemistry, University of Bristol , Bristol, United Kingdom , BS8 1TS
| | - Matthew Bain
- School of Chemistry, University of Bristol , Bristol, United Kingdom , BS8 1TS
| | | | - Rebecca A Ingle
- School of Chemistry, University of Bristol , Bristol, United Kingdom , BS8 1TS
| | - Tolga N V Karsili
- School of Chemistry, University of Bristol , Bristol, United Kingdom , BS8 1TS
| | - Barbara Marchetti
- School of Chemistry, University of Bristol , Bristol, United Kingdom , BS8 1TS
| | - Daniel Murdock
- School of Chemistry, University of Bristol , Bristol, United Kingdom , BS8 1TS
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