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Dantus M. Ultrafast studies of elusive chemical reactions in the gas phase. Science 2024; 385:eadk1833. [PMID: 39116221 DOI: 10.1126/science.adk1833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Accepted: 06/11/2024] [Indexed: 08/10/2024]
Abstract
The chemical composition of the interstellar medium and planetary atmospheres is constantly in flux as atoms and molecules collide and interact with high-energy particles such as electrons, protons, and photons. These transformative processes ultimately lead to the coalescence of molecules and eventually the birth of stars. Our understanding of these chemical ecosystems relies on models that synthesize data from gas-phase experiments, providing insights into reaction cross sections. This Review examines efforts to delve into the fundamental bond-forming and bond-breaking dynamics that occur during bimolecular and electron-initiated reactions. These experiments involve clever approaches to establish a time reference and the collision geometry necessary for tracking atomic motion with femtosecond time resolution. Findings from these efforts enhance present models and improve predictions for molecule-molecule and electron-molecule collisions.
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Affiliation(s)
- Marcos Dantus
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824, USA
- Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI 48824, USA
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Robinson MS, Küpper J. Unraveling the ultrafast dynamics of thermal-energy chemical reactions. Phys Chem Chem Phys 2024; 26:1587-1601. [PMID: 38131437 DOI: 10.1039/d3cp03954d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
In this perspective, we discuss how one can initiate, image, and disentangle the ultrafast elementary steps of thermal-energy chemical dynamics, building upon advances in technology and scientific insight. We propose that combinations of ultrashort mid-infrared laser pulses, controlled molecular species in the gas phase, and forefront imaging techniques allow to unravel the elementary steps of general-chemistry reaction processes in real time. We detail, for prototypical first reaction systems, experimental methods enabling these investigations, how to sufficiently prepare and promote gas-phase samples to thermal-energy reactive states with contemporary ultrashort mid-infrared laser systems, and how to image the initiated ultrafast chemical dynamics. The results of such experiments will clearly further our understanding of general-chemistry reaction dynamics.
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Affiliation(s)
- Matthew S Robinson
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany.
- Center for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Jochen Küpper
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany.
- Center for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- Department of Physics, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
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Dowek D, Decleva P. Trends in angle-resolved molecular photoelectron spectroscopy. Phys Chem Chem Phys 2022; 24:24614-24654. [DOI: 10.1039/d2cp02725a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In this perspective article, main trends of angle-resolved molecular photoelectron spectroscopy in the laboratory up to the molecular frame, in different regimes of light-matter interactions, are highlighted with emphasis on foundations and most recent applications.
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Affiliation(s)
- Danielle Dowek
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d’Orsay, 91405 Orsay, France
| | - Piero Decleva
- CNR IOM and Dipartimento DSCF, Università di Trieste, Trieste, Italy
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Li S, Jochim B, Jackson JE, Dantus M. Femtosecond dynamics and coherence of ionic retro-Diels-Alder reactions. J Chem Phys 2021; 155:044303. [PMID: 34340396 DOI: 10.1063/5.0048380] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Ultrafast tunnel ionization enables femtosecond time-resolved dynamic measurements of the retro-Diels-Alder reactions of positively charged cyclohexene, norbornene, and dicyclopentadiene. Unlike the reaction times of 500-600 ps that are observed following UV excitation of neutral species, on the ionic potential energy surfaces, these reactions occur on a single picosecond timescale and, in some cases, exhibit vibrational coherence. In the case of norbornene, a 270 cm-1 vibrational mode is found to modulate the retro-Diels-Alder reaction.
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Affiliation(s)
- Shuai Li
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - Bethany Jochim
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - James E Jackson
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - Marcos Dantus
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
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Ivanov M. Concluding remarks: The age of molecular movies. Faraday Discuss 2021; 228:622-629. [PMID: 33960352 DOI: 10.1039/d1fd90033a] [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
This Faraday Discussion has demonstrated enormous progress towards using advanced light sources, together with a variety of experimental and theoretical tools and techniques, to film the motion of both electrons and nuclei in molecules undergoing photo-induced reactions. The new tools are beginning to offer reliable opportunities for achieving the required spatio-temporal resolution, all the way to sub-femtosecond and sub-angstrom scales. The age of quantum molecular movies has arrived.
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Affiliation(s)
- Misha Ivanov
- Max Born Institute, Max Born Str. 2A, Berlin, Germany
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Sun Z, Yao H, Ren X, Liu Y, Wang D, Zhao W, Wang C, Yang C. Imaging of electron transition and bond breaking in the photodissociation of H 2+ via ultrafast X-ray photoelectron diffraction. OPTICS EXPRESS 2021; 29:10893-10902. [PMID: 33820212 DOI: 10.1364/oe.416927] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 03/08/2021] [Indexed: 06/12/2023]
Abstract
We theoretically investigate the photodissociation dynamics of H2+ using the methodology of ultrafast X-ray photoelectron diffraction (UXPD). We use a femtosecond infrared pulse to prompt a coherent excitation from the molecular vibrational state (v = 9) of the electronic ground state (1sσg) and then adopt another time-delayed attosecond X-ray pulse to probe the dynamical properties. We have calculated photoionization momentum distributions by solving the non-Born-Oppenheimer time-dependent Schrödinger equation (TDSE). We unambiguously identify the phenomena associated with the g - u symmetry breakdown in the time-resolved photoelectron diffraction spectra. Using the two-center interference model, we can determine the variation in nuclear spacing with high accuracy. In addition, we use a strong field approximation (SFA) model to interpret the UXPD profile, and the SFA simulations can reproduce the TDSE results in a quantitative way.
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7
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Setting the photoelectron clock through molecular alignment. Nat Commun 2020; 11:2546. [PMID: 32439923 PMCID: PMC7242449 DOI: 10.1038/s41467-020-16270-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 04/16/2020] [Indexed: 11/09/2022] Open
Abstract
The interaction of strong laser fields with matter intrinsically provides a powerful tool for imaging transient dynamics with an extremely high spatiotemporal resolution. Here, we study strong-field ionisation of laser-aligned molecules, and show a full real-time picture of the photoelectron dynamics in the combined action of the laser field and the molecular interaction. We demonstrate that the molecule has a dramatic impact on the overall strong-field dynamics: it sets the clock for the emission of electrons with a given rescattering kinetic energy. This result represents a benchmark for the seminal statements of molecular-frame strong-field physics and has strong impact on the interpretation of self-diffraction experiments. Furthermore, the resulting encoding of the time-energy relation in molecular-frame photoelectron momentum distributions shows the way of probing the molecular potential in real-time, and accessing a deeper understanding of electron transport during strong-field interactions. Interaction of strong laser fields with matter provides powerful tools to image transient dynamics with high spatiotemporal resolution. The authors investigate strong-field ionisation of laser-aligned molecules showing the effect of molecular alignment on the photoelectron dynamics and the resulting influence of the molecular frame in imaging experiments.
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Karamatskos ET, Goldsztejn G, Raabe S, Stammer P, Mullins T, Trabattoni A, Johansen RR, Stapelfeldt H, Trippel S, Vrakking MJJ, Küpper J, Rouzée A. Atomic-resolution imaging of carbonyl sulfide by laser-induced electron diffraction. J Chem Phys 2019; 150:244301. [PMID: 31255082 DOI: 10.1063/1.5093959] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Measurements on the strong-field ionization of carbonyl sulfide molecules by short, intense, 2 µm wavelength laser pulses are presented from experiments where angle-resolved photoelectron distributions were recorded with a high-energy velocity map imaging spectrometer, designed to reach a maximum kinetic energy of 500 eV. The laser-field-free elastic-scattering cross section of carbonyl sulfide was extracted from the measurements and is found in good agreement with previous experiments, performed using conventional electron diffraction. By comparing our measurements to the results of calculations, based on the quantitative rescattering theory, the bond lengths and molecular geometry were extracted from the experimental differential cross sections to a precision better than ±5 pm and in agreement with the known values.
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Affiliation(s)
- Evangelos T Karamatskos
- Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
| | - Gildas Goldsztejn
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Strasse 2a, 12489 Berlin, Germany
| | - Sebastian Raabe
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Strasse 2a, 12489 Berlin, Germany
| | - Philipp Stammer
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Strasse 2a, 12489 Berlin, Germany
| | - Terry Mullins
- Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
| | - Andrea Trabattoni
- Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
| | - Rasmus R Johansen
- Department of Chemistry, Aarhus University, Langelandsgade 140, DK-8000 Aarhus C, Denmark
| | - Henrik Stapelfeldt
- Department of Chemistry, Aarhus University, Langelandsgade 140, DK-8000 Aarhus C, Denmark
| | - Sebastian Trippel
- Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
| | - Marc J J Vrakking
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Strasse 2a, 12489 Berlin, Germany
| | - Jochen Küpper
- Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
| | - Arnaud Rouzée
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Strasse 2a, 12489 Berlin, Germany
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