1
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Walmsley T, McManus JW, Kumagai Y, Nagaya K, Harries J, Iwayama H, Ashfold MNR, Britton M, Bucksbaum PH, Downes-Ward B, Driver T, Heathcote D, Hockett P, Howard AJ, Lee JWL, Liu Y, Kukk E, Milesevic D, Minns RS, Niozu A, Niskanen J, Orr-Ewing AJ, Owada S, Robertson PA, Rolles D, Rudenko A, Ueda K, Unwin J, Vallance C, Brouard M, Burt M, Allum F, Forbes R. The Role of Momentum Partitioning in Covariance Ion Imaging Analysis. J Phys Chem A 2024; 128:4548-4560. [PMID: 38713032 DOI: 10.1021/acs.jpca.4c00999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
We present results from a covariance ion imaging study, which employs extensive filtering, on the relationship between fragment momenta to gain deeper insight into photofragmentation dynamics. A new data analysis approach is introduced that considers the momentum partitioning between the fragments of the breakup of a molecular polycation to disentangle concurrent fragmentation channels, which yield the same ion species. We exploit this approach to examine the momentum exchange relationship between the products, which provides direct insight into the dynamics of molecular fragmentation. We apply these techniques to extensively characterize the dissociation of 1-iodopropane and 2-iodopropane dications prepared by site-selective ionization of the iodine atom using extreme ultraviolet intense femtosecond laser pulses with a photon energy of 95 eV. Our assignments are supported by classical simulations, using parameters largely obtained directly from the experimental data.
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Affiliation(s)
- Tiffany Walmsley
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K
| | - Joseph W McManus
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K
| | - Yoshiaki Kumagai
- Department of Applied Physics, Tokyo University of Agriculture and Technology, Tokyo 184-8588, Japan
| | - Kiyonobu Nagaya
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - James Harries
- National Institutes for Quantum Science and Technology (QST), SPring-8, Kouto 1-1-1, Sayo, Hyogo 679-5148, Japan
| | - Hiroshi Iwayama
- Institute for Molecular Science, Okazaki 444-8585, Japan
- Sokendai (The Graduate University for Advanced Studies), Okazaki 444-8585, Japan
| | | | - Mathew Britton
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Philip H Bucksbaum
- PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Briony Downes-Ward
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, U.K
| | - Taran Driver
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - David Heathcote
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K
| | - Paul Hockett
- National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada
| | - Andrew J Howard
- PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Jason W L Lee
- Deutsches Elektronen-Synchrotron (DESY), Hamburg 22607, Germany
| | - Yusong Liu
- PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Edwin Kukk
- Department of Physics and Astronomy, University of Turku, Turku FI-20014, Finland
| | - Dennis Milesevic
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K
| | - Russell S Minns
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, U.K
| | - Akinobu Niozu
- Graduate School of Advanced Science and Engineering, Hiroshima University, Hiroshima 739-8526, Japan
| | - Johannes Niskanen
- Department of Physics and Astronomy, University of Turku, Turku FI-20014, Finland
| | | | - Shigeki Owada
- RIKEN SPring-8 Center, Sayo, Hyogo 679-5148, Japan
- Japan Synchrotron Radiation Research Institute, Sayo, Hyogo 679-5198, Japan
| | - Patrick A Robertson
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K
| | - Daniel Rolles
- J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506, United States
| | - Artem Rudenko
- J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506, United States
| | - Kiyoshi Ueda
- Department of Chemistry, Tohoku University, Sendai 980-8578, Japan
| | - James Unwin
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K
| | - Claire Vallance
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K
| | - Mark Brouard
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K
| | - Michael Burt
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K
| | - Felix Allum
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
- PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Ruaridh Forbes
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
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McManus JW, Allum F, Featherstone J, Lam CS, Brouard M. Two-Dimensional Projected-Momentum Covariance Mapping for Coulomb Explosion Imaging. J Phys Chem A 2024; 128:3220-3229. [PMID: 38607425 PMCID: PMC11056990 DOI: 10.1021/acs.jpca.4c01084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 03/28/2024] [Accepted: 03/29/2024] [Indexed: 04/13/2024]
Abstract
We introduce projected-momentum covariance mapping, an extension of recoil-frame covariance mapping for 2D ion imaging studies. By considering the two-dimensional projection of the ion momenta as recorded by the detector, one opens the door to a complex suite of analysis tools adapted from three-dimensional momentum imaging studies. This includes the use of different frames of reference to unravel the dynamics of fragmentation and the application of fragment momentum constraints to isolate specific fragmentation channels. The technique is demonstrated on data from a two-dimensional ion imaging study of the Coulomb explosion of the cis and trans isomers of 1,2-dichloroethene, following strong-field ionization by an intense near-infrared femtosecond laser pulse. Classical simulations are used to guide the interpretation of projected-momentum covariance maps. The results offer a detailed insight into the distinct Coulomb explosion dynamics for this pair of isomers and lay the groundwork for future time-resolved studies of photoisomerization dynamics in this molecular system.
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Affiliation(s)
- Joseph W. McManus
- Chemistry Research Laboratory,
Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K.
| | | | - Josh Featherstone
- Chemistry Research Laboratory,
Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K.
| | - Chow-Shing Lam
- Chemistry Research Laboratory,
Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K.
| | - Mark Brouard
- Chemistry Research Laboratory,
Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K.
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3
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Lam HVS, Venkatachalam AS, Bhattacharyya S, Chen K, Borne K, Wang E, Boll R, Jahnke T, Kumarappan V, Rudenko A, Rolles D. Differentiating Three-Dimensional Molecular Structures Using Laser-Induced Coulomb Explosion Imaging. PHYSICAL REVIEW LETTERS 2024; 132:123201. [PMID: 38579208 DOI: 10.1103/physrevlett.132.123201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Accepted: 02/12/2024] [Indexed: 04/07/2024]
Abstract
Coulomb explosion imaging (CEI) with x-ray free electron lasers has recently been shown to be a powerful method for obtaining detailed structural information of gas-phase planar ring molecules [R. Boll et al., X-ray multiphoton-induced Coulomb explosion images complex single molecules, Nat. Phys. 18, 423 (2022).NPAHAX1745-247310.1038/s41567-022-01507-0]. In this Letter, we investigate the potential of CEI driven by a tabletop laser and extend this approach to differentiating three-dimensional structures. We study the static CEI patterns of planar and nonplanar organic molecules that resemble the structures of typical products formed in ring-opening reactions. Our results reveal that each molecule exhibits a well-localized and distinctive pattern in three-dimensional fragment-ion momentum space. We find that these patterns yield direct information about the molecular structures and can be qualitatively reproduced using a classical Coulomb explosion simulation. Our findings suggest that laser-induced CEI can serve as a robust method for differentiating molecular structures of organic ring and chain molecules. As such, it holds great promise as a method for following ultrafast structural changes, e.g., during ring-opening reactions, by tracking the motion of individual atoms in pump-probe experiments.
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Affiliation(s)
- Huynh Van Sa Lam
- James R. Macdonald Laboratory, Kansas State University, Manhattan, Kansas 66506, USA
| | | | | | - Keyu Chen
- James R. Macdonald Laboratory, Kansas State University, Manhattan, Kansas 66506, USA
| | - Kurtis Borne
- James R. Macdonald Laboratory, Kansas State University, Manhattan, Kansas 66506, USA
| | - Enliang Wang
- James R. Macdonald Laboratory, Kansas State University, Manhattan, Kansas 66506, USA
| | | | | | - Vinod Kumarappan
- James R. Macdonald Laboratory, Kansas State University, Manhattan, Kansas 66506, USA
| | - Artem Rudenko
- James R. Macdonald Laboratory, Kansas State University, Manhattan, Kansas 66506, USA
| | - Daniel Rolles
- James R. Macdonald Laboratory, Kansas State University, Manhattan, Kansas 66506, USA
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4
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Crane SW, Lee JWL, Ashfold MNR, Rolles D. Molecular photodissociation dynamics revealed by Coulomb explosion imaging. Phys Chem Chem Phys 2023. [PMID: 37335247 DOI: 10.1039/d3cp01740k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2023]
Abstract
Coulomb explosion imaging (CEI) methods are finding ever-growing use as a means of exploring and distinguishing the static stereo-configurations of small quantum systems (molecules, clusters, etc). CEI experiments initiated by ultrafast (femtosecond-duration) laser pulses also allow opportunities to track the time-evolution of molecular structures, and thereby advance understanding of molecular fragmentation processes. This Perspective illustrates two emerging families of dynamical studies. 'One-colour' studies (employing strong field ionisation driven by intense near infrared or single X-ray or extreme ultraviolet laser pulses) afford routes to preparing multiply charged molecular cations and exploring how their fragmentation progresses from valence-dominated to Coulomb-dominated dynamics with increasing charge and how this evolution varies with molecular size and composition. 'Two-colour' studies use one ultrashort laser pulse to create electronically excited neutral molecules (or monocations), whose structural evolution is then probed as a function of pump-probe delay using an ultrafast ionisation pulse along with time and position-sensitive detection methods. This latter type of experiment has the potential to return new insights into not just molecular fragmentation processes but also charge transfer processes between moieties separating with much better defined stereochemical control than in contemporary ion-atom and ion-molecule charge transfer studies.
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Affiliation(s)
- Stuart W Crane
- School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK.
| | - Jason W L Lee
- Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK
| | | | - Daniel Rolles
- J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, KS 66506, USA
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5
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Heathcote D, Robertson PA, Butler AA, Ridley C, Lomas J, Buffett MM, Bell M, Vallance C. Electron-induced dissociation dynamics studied using covariance-map imaging. Faraday Discuss 2022; 238:682-699. [PMID: 35781475 DOI: 10.1039/d2fd00033d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Recently, covariance analysis has found significant use in the field of chemical reaction dynamics. When coupled with data from product time-of-flight mass spectrometry and/or multi-mass velocity-map imaging, it allows us to uncover correlations between two or more ions formed from the same parent molecule. While the approach has parallels with coincidence measurements, covariance analysis allows experiments to be performed at much higher count rates than traditional coincidence methods. We report results from electron-molecule crossed-beam experiments, in which covariance analysis is used to elucidate the dissociation dynamics of multiply-charged ions formed by electron ionisation over the energy range from 50 to 300 eV. The approach is able to isolate signal contributions from multiply charged ions even against a very large 'background' of signal arising from dissociation of singly-charged parent ions. Covariance between the product time-of-flight spectra identifies pairs of fragments arising from the same parent ions, while covariances between the velocity-map images ('recoil-frame covariances') reveal the relative velocity distributions of the ion pairs. We show that recoil-frame covariance analysis can be used to distinguish between multiple plausible dissociation mechanisms, including multi-step processes, and that the approach becomes particularly powerful when investigating the fragmentation dynamics of larger molecules with a higher number of possible fragmentation pathways.
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Affiliation(s)
- David Heathcote
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, UK.
| | - Patrick A Robertson
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, UK.
| | - Alexander A Butler
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, UK.
| | - Cian Ridley
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, UK.
| | - James Lomas
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, UK.
| | - Madeline M Buffett
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, UK.
| | - Megan Bell
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, UK.
| | - Claire Vallance
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, UK.
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6
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McManus JW, Walmsley T, Nagaya K, Harries JR, Kumagai Y, Iwayama H, Ashfold MNR, Britton M, Bucksbaum PH, Downes-Ward B, Driver T, Heathcote D, Hockett P, Howard AJ, Kukk E, Lee JWL, Liu Y, Milesevic D, Minns RS, Niozu A, Niskanen J, Orr-Ewing AJ, Owada S, Rolles D, Robertson PA, Rudenko A, Ueda K, Unwin J, Vallance C, Burt M, Brouard M, Forbes R, Allum F. Disentangling sequential and concerted fragmentations of molecular polycations with covariant native frame analysis. Phys Chem Chem Phys 2022; 24:22699-22709. [PMID: 36106844 DOI: 10.1039/d2cp03029b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present results from an experimental ion imaging study into the fragmentation dynamics of 1-iodopropane and 2-iodopropane following interaction with extreme ultraviolet intense femtosecond laser pulses with a photon energy of 95 eV. Using covariance imaging analysis, a range of observed fragmentation pathways of the resulting polycations can be isolated and interrogated in detail at relatively high ion count rates (∼12 ions shot-1). By incorporating the recently developed native frames analysis approach into the three-dimensional covariance imaging procedure, contributions from three-body concerted and sequential fragmentation mechanisms can be isolated. The angular distribution of the fragment ions is much more complex than in previously reported studies for triatomic polycations, and differs substantially between the two isomeric species. With support of simple simulations of the dissociation channels of interest, detailed physical insights into the fragmentation dynamics are obtained, including how the initial dissociation step in a sequential mechanism influences rovibrational dynamics in the metastable intermediate ion and how signatures of this nuclear motion manifest in the measured signals.
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Affiliation(s)
- Joseph W McManus
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
| | - Tiffany Walmsley
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
| | - Kiyonobu Nagaya
- Department of Physics, Kyoto University, Kyoto, 606-8502, Japan
| | | | - Yoshiaki Kumagai
- Department of Applied Physics, Tokyo University of Agriculture and Technology, Koganei-shi, Tokyo 184-8588, Japan
| | - Hiroshi Iwayama
- UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
| | - Michael N R Ashfold
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Mathew Britton
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Philip H Bucksbaum
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Briony Downes-Ward
- Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK
| | - Taran Driver
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - David Heathcote
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
| | - Paul Hockett
- National Research Council of Canada, 100 Sussex Dr., Ottawa, ON K1A 0R6, Canada
| | - Andrew J Howard
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Edwin Kukk
- Department of Physics and Astronomy, University of Turku, Turku, FI-20014, Finland
| | - Jason W L Lee
- Deutsches Elektronen-Synchrotron (DESY), Notkestraße 85, 22607 Hamburg, Germany
| | - Yusong Liu
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Dennis Milesevic
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
| | - Russell S Minns
- Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK
| | - Akinobu Niozu
- Graduate School of Advanced Science and Engineering, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Johannes Niskanen
- Department of Physics and Astronomy, University of Turku, Turku, FI-20014, Finland
| | - Andrew J Orr-Ewing
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Shigeki Owada
- RIKEN SPring-8 Center, Sayo, Hyogo, 679-5148, Japan.,Japan Synchrotron Radiation Research Institute, Hyogo, Japan
| | - Daniel Rolles
- J. R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, KS, 66506, USA
| | - Patrick A Robertson
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
| | - Artem Rudenko
- J. R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, KS, 66506, USA
| | - Kiyoshi Ueda
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, 980-8577, Japan
| | - James Unwin
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
| | - Claire Vallance
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
| | - Michael Burt
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
| | - Mark Brouard
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
| | - Ruaridh Forbes
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
| | - Felix Allum
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK.,Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA.,Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
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Crane SW, Lee JWL, Ashfold MNR. Multi-mass velocity map imaging study of the 805 nm strong field ionization of CF 3I. Phys Chem Chem Phys 2022; 24:18830-18840. [PMID: 35904364 DOI: 10.1039/d2cp02449g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Multi-mass velocity map imaging studies of charged fragments formed by near infrared strong field ionization together with covariance map image analysis offer a new window through which to explore the dissociation dynamics of several different highly charged parent cations, simultaneously - as demonstrated here for the case of CF3IZ+ cations with charges Z ranging from 1 to at least 5. Previous reports that dissociative ionization of CF3I+ cations yields CF3+, I+ and CF2I+ fragment ions are confirmed, and some of the CF3+ fragments are deduced to undergo secondary loss of one or more neutral F atoms. Covariance map imaging confirms the dominance of CF3+ + I+ products in the photodissociation of CF3I2+ cations and, again, that some of the primary CF3+ photofragments can shed one or more F atoms. Rival charge symmetric dissociation pathways to CF2I+ + F+ and to IF+ + CF2+ products and charge asymmetric dissociations to CF3 + I2+ and CF2I2+ + F products are all also identified. The findings for parent cations with Z ≥ 3 are wholly new. In all cases, the fragment recoil velocity distributions imply dissociation dynamics in which coulombic repulsive forces play a dominant role. The major photoproducts following dissociation of CF3I3+ ions are CF3+ and I2+, with lesser contributions from the rival CF2I2+ + F+ and CF32+ + I+ channels. The CF32+ fragment ion images measured at higher incident intensities show a faster velocity sub-group consistent with their formation in tandem with I2+ fragments, from photodissociation of CF3I4+ parent ions. The measured velocity distributions of the I3+ fragment ions contain features attributable to CF3I5+ photodissociation to CF32+ + I3+ and the images of fragments with mass to charge (m/z) ratio ∼31 show formation of I4+ products that must originate from parent ions with yet higher Z.
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Affiliation(s)
- Stuart W Crane
- School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK.
| | - Jason W L Lee
- Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK.,Deutsches Elektronen-Synchrotron DESY, D-22607 Hamburg, Germany
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8
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Schouder CA, Chatterley AS, Pickering JD, Stapelfeldt H. Laser-Induced Coulomb Explosion Imaging of Aligned Molecules and Molecular Dimers. Annu Rev Phys Chem 2022; 73:323-347. [PMID: 35081323 DOI: 10.1146/annurev-physchem-090419-053627] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We discuss how Coulomb explosion imaging (CEI), triggered by intense femtosecond laser pulses and combined with laser-induced alignment and covariance analysis of the angular distributions of the recoiling fragment ions, provides new opportunities for imaging the structures of molecules and molecular complexes. First, focusing on gas phase molecules, we show how the periodic torsional motion of halogenated biphenyl molecules can be measured in real time by timed CEI, and how CEI of one-dimensionally aligned difluoroiodobenzene molecules can uniquely identify four structural isomers. Next, focusing on molecular complexes formed inside He nanodroplets, we show that the conformations of noncovalently bound dimers or trimers, aligned in one or three dimensions, can be determined by CEI. Results presented for homodimers of CS2, OCS, and bromobenzene pave the way for femtosecond time-resolved structure imaging of molecules undergoing bimolecular interactions and ultimately chemical reactions. Expected final online publication date for the Annual Review of Physical Chemistry, Volume 73 is April 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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9
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Minion LA, Lee JW, Burt M. Predicting Coulomb explosion fragment angular distributions using molecular ground-state vibrational motion. Phys Chem Chem Phys 2022; 24:11636-11645. [DOI: 10.1039/d2cp01114j] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Laser-induced Coulomb explosions can be used to identify gas-phase molecular structures through correlations between fragment ion trajectories. This report presents a model for predicting these outcomes, which first establishes the...
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10
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Crane SW, Ge L, Cooper GA, Carwithen BP, Bain M, Smith JA, Hansen CS, Ashfold MNR. Nonadiabatic Coupling Effects in the 800 nm Strong-Field Ionization-Induced Coulomb Explosion of Methyl Iodide Revealed by Multimass Velocity Map Imaging and Ab Initio Simulation Studies. J Phys Chem A 2021; 125:9594-9608. [PMID: 34709807 DOI: 10.1021/acs.jpca.1c06346] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The Coulomb explosion (CE) of jet-cooled CH3I molecules using ultrashort (40 fs), nonresonant 805 nm strong-field ionization at three peak intensities (260, 650, and 1300 TW cm-2) has been investigated by multimass velocity map imaging, revealing an array of discernible fragment ions, that is, Iq+ (q ≤ 6), CHn+ (n = 0-3), CHn2+ (n = 0, 2), C3+, H+, H2+, and H3+. Complementary ab initio trajectory calculations of the CE of CH3IZ+ cations with Z ≤ 14 identify a range of behaviors. The CE of parent cations with Z = 2 and 3 can be well-described using a diatomic-like representation (as found previously) but the CE dynamics of all higher CH3IZ+ cations require a multidimensional description. The ab initio predicted Iq+ (q ≥ 3) fragment ion velocities are all at the high end of the velocity distributions measured for the corresponding Iq+ products. These mismatches are proposed as providing some of the clearest insights yet into the roles of nonadiabatic effects (and intramolecular charge transfer) in the CE of highly charged molecular cations.
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Affiliation(s)
- Stuart W Crane
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - Lingfeng Ge
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - Graham A Cooper
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - Ben P Carwithen
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - Matthew Bain
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - James A Smith
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - Christopher S Hansen
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - Michael N R Ashfold
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
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11
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Vallance C, Heathcote D, Lee JWL. Covariance-Map Imaging: A Powerful Tool for Chemical Dynamics Studies. J Phys Chem A 2021; 125:1117-1133. [DOI: 10.1021/acs.jpca.0c10038] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Claire Vallance
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, U.K
| | - David Heathcote
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, U.K
| | - Jason W. L. Lee
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, U.K
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