1
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Hoffmann L, Toulson BW, Yang J, Saladrigas CA, Zong A, Muvva SB, Figueira Nunes JP, Reid AH, Attar AR, Luo D, Ji F, Lin MF, Fan Q, Weathersby SP, Shen X, Wang X, Wolf TJA, Neumark DM, Leone SR, Zuerch MW, Centurion M, Gessner O. UV-Induced Reaction Pathways in Bromoform Probed with Ultrafast Electron Diffraction. J Am Chem Soc 2024. [PMID: 39374484 DOI: 10.1021/jacs.4c07165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/09/2024]
Abstract
For many chemical reactions, it remains notoriously difficult to predict and experimentally determine the rates and branching ratios between different reaction channels. This is particularly the case for reactions involving short-lived intermediates, whose observation requires ultrafast methods. The UV photochemistry of bromoform (CHBr3) is among the most intensely studied photoreactions. Yet, a detailed understanding of the chemical pathways leading to the production of atomic Br and molecular Br2 fragments has proven challenging. In particular, the role of isomerization and/or roaming and their competition with direct C-Br bond scission has been a matter of continued debate. Here, gas-phase ultrafast megaelectronvolt electron diffraction (MeV-UED) is used to directly study structural dynamics in bromoform after single 267 nm photon excitation with femtosecond temporal resolution. The results show unambiguously that isomerization contributes significantly to the early stages of the UV photochemistry of bromoform. In addition to direct C-Br bond breaking within <200 fs, formation of iso-CHBr3 (Br-CH-Br-Br) is observed on the same time scale and with an isomer lifetime of >1.1 ps. The branching ratio between direct dissociation and isomerization is determined to be 0.4 ± 0.2:0.6 ± 0.2, i.e., approximately 60% of molecules undergo isomerization within the first few hundred femtoseconds after UV excitation. The structure and time of formation of iso-CHBr3 compare favorably with the results of an ab initio molecular dynamics simulation. The lifetime and interatomic distances of the isomer are consistent with the involvement of a roaming reaction mechanism.
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Affiliation(s)
- Lars Hoffmann
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Benjamin W Toulson
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Jie Yang
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Catherine A Saladrigas
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Alfred Zong
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Sri Bhavya Muvva
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Joao Pedro Figueira Nunes
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Alexander H Reid
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Andrew R Attar
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Duan Luo
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Fuhao Ji
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Ming-Fu Lin
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Qingyuan Fan
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Stephen P Weathersby
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Xiaozhe Shen
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Xijie Wang
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Thomas J A Wolf
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Daniel M Neumark
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Stephen R Leone
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Department of Physics, University of California, Berkeley, California 94720, United States
| | - Michael W Zuerch
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Martin Centurion
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Oliver Gessner
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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2
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Sun S, Yong H, Chernyak VY, Mukamel S. Self-Heterodyne Diffractive Imaging of Ultrafast Electron Dynamics Monitored by Single-Electron Pulses. PHYSICAL REVIEW LETTERS 2024; 133:093001. [PMID: 39270182 DOI: 10.1103/physrevlett.133.093001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 02/08/2024] [Accepted: 07/18/2024] [Indexed: 09/15/2024]
Abstract
The direct imaging of time-evolving molecular charge densities on atomistic scale and at femtosecond resolution has long been an elusive task. In this theoretical study, we propose a self-heterodyne electron diffraction technique based on single electron pulses. The electron is split into two beams, one passes through the sample and its interference with the second beam produces a heterodyne diffraction signal that images the charge density. Application to probing the ultrafast electronic dynamics in Mg-phthalocyanine demonstrates its potential for imaging chemical dynamics.
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Affiliation(s)
| | | | - Vladimir Y Chernyak
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, Michigan 48202, USA
- Department of Mathematics, Wayne State University, 656 West Kirby, Detroit, Michigan 48202, USA
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3
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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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4
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Miller ER, Hoehn SJ, Kumar A, Jiang D, Parker SM. Ultrafast photochemistry and electron diffraction for cyclobutanone in the S2 state: Surface hopping with time-dependent density functional theory. J Chem Phys 2024; 161:034105. [PMID: 39007373 DOI: 10.1063/5.0203679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 06/26/2024] [Indexed: 07/16/2024] Open
Abstract
We simulate the photodynamics of gas-phase cyclobutanone excited to the S2 state using fewest switches surface hopping (FSSH) dynamics powered by time-dependent density functional theory (TDDFT). We predict a total photoproduct yield of 8%, with a C3:C2 product ratio of 0 trajectories to 8 trajectories. One primary S2 → S1 conical intersection is identified involving the compression of an α-carbon-carbon-hydrogen bond angle. Excited state lifetimes computed with respect to electronic state populations were found to be 3.96 ps (S2 → S1) and 498 fs (S1 → S0). We also generate time-resolved difference pair distribution functions (ΔPDFs) from our TDDFT-FSSH dynamics results in order to generate direct comparisons with ultrafast electron diffraction experiment observables. Global and target analysis of time-resolved ΔPDFs produced a distinct set of lifetimes: (i) a 0.548 ps decay and (ii) a 1.69 ps decay, both resembling the S2 minimum, as well as (iii) a long decay that resembles the S1 minimum geometry and the fully separated C2 products. Finally, we contextualize our results by considering the impact of the most likely sources of significant errors.
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Affiliation(s)
- Ericka Roy Miller
- Department of Chemistry, Case Western Reserve University, 10900 Euclid Ave., Cleveland, Ohio 44106, USA
| | - Sean J Hoehn
- Department of Chemistry, Case Western Reserve University, 10900 Euclid Ave., Cleveland, Ohio 44106, USA
| | - Abhijith Kumar
- Department of Chemistry, Case Western Reserve University, 10900 Euclid Ave., Cleveland, Ohio 44106, USA
| | - Dehua Jiang
- Department of Chemistry, Case Western Reserve University, 10900 Euclid Ave., Cleveland, Ohio 44106, USA
| | - Shane M Parker
- Department of Chemistry, Case Western Reserve University, 10900 Euclid Ave., Cleveland, Ohio 44106, USA
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5
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Nunes JPF, Williams M, Yang J, Wolf TJA, Rankine CD, Parrish R, Moore B, Wilkin K, Shen X, Lin MF, Hegazy K, Li R, Weathersby S, Martinez TJ, Wang XJ, Centurion M. Photo-induced structural dynamics of o-nitrophenol by ultrafast electron diffraction. Phys Chem Chem Phys 2024; 26:17991-17998. [PMID: 38764355 DOI: 10.1039/d3cp06253h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/21/2024]
Abstract
The photo-induced dynamics of o-nitrophenol, particularly its photolysis, has garnered significant scientific interest as a potential source of nitrous acid in the atmosphere. Although the photolysis products and preceding photo-induced electronic structure dynamics have been investigated extensively, the nuclear dynamics accompanying the non-radiative relaxation of o-nitrophenol on the ultrafast timescale, which include an intramolecular proton transfer step, have not been experimentally resolved. Herein, we present a direct observation of the ultrafast nuclear motions mediating photo-relaxation using ultrafast electron diffraction. This work spatiotemporally resolves the loss of planarity which enables access to a conical intersection between the first excited state and the ground state after the proton transfer step, on the femtosecond timescale and with sub-Angstrom resolution. Our observations, supported by ab initio multiple spawning simulations, provide new insights into the proton transfer mediated relaxation mechanism in o-nitrophenol.
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Affiliation(s)
- J P F Nunes
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, USA.
| | - M Williams
- SLAC National Accelerator Laboratory, Menlo Park, USA
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, USA
- Department of Chemistry, Stanford University, Stanford, USA
| | - J Yang
- SLAC National Accelerator Laboratory, Menlo Park, USA
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, USA
- Center of Basic Molecular Science, Department of Chemistry, Tsinghua University, Beijing, China
| | - T J A Wolf
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, USA
| | - C D Rankine
- School of Natural and Environmental Sciences, Newcastle University, UK
| | - R Parrish
- SLAC National Accelerator Laboratory, Menlo Park, USA
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, USA
- Department of Chemistry, Stanford University, Stanford, USA
| | - B Moore
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, USA.
| | - K Wilkin
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, USA.
| | - X Shen
- SLAC National Accelerator Laboratory, Menlo Park, USA
| | - Ming-Fu Lin
- SLAC National Accelerator Laboratory, Menlo Park, USA
| | - K Hegazy
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, USA
- Department of Physics, Stanford University, Stanford, USA
| | - R Li
- SLAC National Accelerator Laboratory, Menlo Park, USA
| | - S Weathersby
- SLAC National Accelerator Laboratory, Menlo Park, USA
| | - T J Martinez
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, USA
- Department of Chemistry, Stanford University, Stanford, USA
| | - X J Wang
- SLAC National Accelerator Laboratory, Menlo Park, USA
- Physics Department, Universität Duisburg Essen, 47052 Duisburg, Research Center Chemical Sciences and Sustainability, Research Alliance Ruhr, 44780 Bochum, Germany
- Physics Department, Technische Universität Dortmund, 44221 Dortmund, Research Center Chemical Sciences and Sustainability, Research Alliance Ruhr, 44780 Bochum, Germany
| | - M Centurion
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, USA.
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6
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Chirvi K, Biegert J. Laser-induced electron diffraction: Imaging of a single gas-phase molecular structure with one of its own electrons. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2024; 11:041301. [PMID: 39221452 PMCID: PMC11365610 DOI: 10.1063/4.0000237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 07/22/2024] [Indexed: 09/04/2024]
Abstract
Among the many methods to image molecular structure, laser-induced electron diffraction (LIED) can image a single gas-phase molecule by locating all of a molecule's atoms in space and time. The method is based on attosecond electron recollision driven by a laser field and can reach attosecond temporal resolution. Implementation with a mid-IR laser and cold-target recoil ion-momentum spectroscopy, single molecules are measured with picometer resolution due to the keV electron impact energy without ensemble averaging or the need for molecular orientation. Nowadays, the method has evolved to detect single complex and chiral molecular structures in 3D. The review will touch on the various methods to discuss the implementations of LIED toward single-molecule imaging and complement the discussions with noteworthy experimental findings in the field.
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Affiliation(s)
- K. Chirvi
- ICFO—Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | - J. Biegert
- Author to whom correspondence should be addressed:
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7
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Diaz FR, Mero M, Amini K. High-repetition-rate ultrafast electron diffraction with direct electron detection. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2024; 11:054302. [PMID: 39346930 PMCID: PMC11438501 DOI: 10.1063/4.0000256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Accepted: 08/06/2024] [Indexed: 10/01/2024]
Abstract
Ultrafast electron diffraction (UED) instruments typically operate at kHz or lower repetition rates and rely on indirect detection of electrons. However, these experiments encounter limitations because they are required to use electron beams containing a relatively large number of electrons (≫100 electrons/pulse), leading to severe space-charge effects. Consequently, electron pulses with long durations and large transverse diameters are used to interrogate the sample. Here, we introduce a novel UED instrument operating at a high repetition rate and employing direct electron detection. We operate significantly below the severe space-charge regime by using electron beams containing 1-140 electrons per pulse at 30 kHz. We demonstrate the ability to detect time-resolved signals from thin film solid samples with a difference contrast signal, Δ I / I 0 , and an instrument response function as low as 10-5 and 184-fs (FWHM), respectively, without temporal compression. Overall, our findings underscore the importance of increasing the repetition rate of UED experiments and adopting a direct electron detection scheme, which will be particularly impactful for gas-phase UED. Our newly developed scheme enables more efficient and sensitive investigations of ultrafast dynamics in photoexcited samples using ultrashort electron beams.
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Affiliation(s)
- F. R. Diaz
- Max-Born-Institut, Max-Born-Straße 2A, 12489 Berlin, Germany
| | - M. Mero
- Max-Born-Institut, Max-Born-Straße 2A, 12489 Berlin, Germany
| | - K. Amini
- Max-Born-Institut, Max-Born-Straße 2A, 12489 Berlin, Germany
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8
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Ji F, Edelen A, Roussel R, Shen X, Miskovich S, Weathersby S, Luo D, Mo M, Kramer P, Mayes C, Othman MAK, Nanni E, Wang X, Reid A, Minitti M, England RJ. Multi-objective Bayesian active learning for MeV-ultrafast electron diffraction. Nat Commun 2024; 15:4726. [PMID: 38830874 PMCID: PMC11148007 DOI: 10.1038/s41467-024-48923-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 05/16/2024] [Indexed: 06/05/2024] Open
Abstract
Ultrafast electron diffraction using MeV energy beams(MeV-UED) has enabled unprecedented scientific opportunities in the study of ultrafast structural dynamics in a variety of gas, liquid and solid state systems. Broad scientific applications usually pose different requirements for electron probe properties. Due to the complex, nonlinear and correlated nature of accelerator systems, electron beam property optimization is a time-taking process and often relies on extensive hand-tuning by experienced human operators. Algorithm based efficient online tuning strategies are highly desired. Here, we demonstrate multi-objective Bayesian active learning for speeding up online beam tuning at the SLAC MeV-UED facility. The multi-objective Bayesian optimization algorithm was used for efficiently searching the parameter space and mapping out the Pareto Fronts which give the trade-offs between key beam properties. Such scheme enables an unprecedented overview of the global behavior of the experimental system and takes a significantly smaller number of measurements compared with traditional methods such as a grid scan. This methodology can be applied in other experimental scenarios that require simultaneously optimizing multiple objectives by explorations in high dimensional, nonlinear and correlated systems.
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Affiliation(s)
- Fuhao Ji
- SLAC National Accelerator Laboratory, Menlo Park, 94025, California, USA.
| | - Auralee Edelen
- SLAC National Accelerator Laboratory, Menlo Park, 94025, California, USA
| | - Ryan Roussel
- SLAC National Accelerator Laboratory, Menlo Park, 94025, California, USA
| | - Xiaozhe Shen
- SLAC National Accelerator Laboratory, Menlo Park, 94025, California, USA
| | - Sara Miskovich
- SLAC National Accelerator Laboratory, Menlo Park, 94025, California, USA
| | - Stephen Weathersby
- SLAC National Accelerator Laboratory, Menlo Park, 94025, California, USA
| | - Duan Luo
- SLAC National Accelerator Laboratory, Menlo Park, 94025, California, USA
| | - Mianzhen Mo
- SLAC National Accelerator Laboratory, Menlo Park, 94025, California, USA
| | - Patrick Kramer
- SLAC National Accelerator Laboratory, Menlo Park, 94025, California, USA
| | - Christopher Mayes
- SLAC National Accelerator Laboratory, Menlo Park, 94025, California, USA
| | - Mohamed A K Othman
- SLAC National Accelerator Laboratory, Menlo Park, 94025, California, USA
| | - Emilio Nanni
- SLAC National Accelerator Laboratory, Menlo Park, 94025, California, USA
| | - Xijie Wang
- SLAC National Accelerator Laboratory, Menlo Park, 94025, California, USA
| | - Alexander Reid
- SLAC National Accelerator Laboratory, Menlo Park, 94025, California, USA
| | - Michael Minitti
- SLAC National Accelerator Laboratory, Menlo Park, 94025, California, USA
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9
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Lee Y, Oang KY, Kim D, Ihee H. A comparative review of time-resolved x-ray and electron scattering to probe structural dynamics. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2024; 11:031301. [PMID: 38706888 PMCID: PMC11065455 DOI: 10.1063/4.0000249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 04/10/2024] [Indexed: 05/07/2024]
Abstract
The structure of molecules, particularly the dynamic changes in structure, plays an essential role in understanding physical and chemical phenomena. Time-resolved (TR) scattering techniques serve as crucial experimental tools for studying structural dynamics, offering direct sensitivity to molecular structures through scattering signals. Over the past decade, the advent of x-ray free-electron lasers (XFELs) and mega-electron-volt ultrafast electron diffraction (MeV-UED) facilities has ushered TR scattering experiments into a new era, garnering significant attention. In this review, we delve into the basic principles of TR scattering experiments, especially focusing on those that employ x-rays and electrons. We highlight the variations in experimental conditions when employing x-rays vs electrons and discuss their complementarity. Additionally, cutting-edge XFELs and MeV-UED facilities for TR x-ray and electron scattering experiments and the experiments performed at those facilities are reviewed. As new facilities are constructed and existing ones undergo upgrades, the landscape for TR x-ray and electron scattering experiments is poised for further expansion. Through this review, we aim to facilitate the effective utilization of these emerging opportunities, assisting researchers in delving deeper into the intricate dynamics of molecular structures.
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Affiliation(s)
| | - Key Young Oang
- Radiation Center for Ultrafast Science, Korea Atomic Energy Research Institute (KAERI), Daejeon 34057, South Korea
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10
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Janoš J, Figueira Nunes JP, Hollas D, Slavíček P, Curchod BFE. Predicting the photodynamics of cyclobutanone triggered by a laser pulse at 200 nm and its MeV-UED signals-A trajectory surface hopping and XMS-CASPT2 perspective. J Chem Phys 2024; 160:144305. [PMID: 38591685 DOI: 10.1063/5.0203105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 03/14/2024] [Indexed: 04/10/2024] Open
Abstract
This work is part of a prediction challenge that invited theoretical/computational chemists to predict the photochemistry of cyclobutanone in the gas phase, excited at 200 nm by a laser pulse, and the expected signal that will be recorded during a time-resolved megaelectronvolt ultrafast electron diffraction (MeV-UED). We present here our theoretical predictions based on a combination of trajectory surface hopping with XMS-CASPT2 (for the nonadiabatic molecular dynamics) and Born-Oppenheimer molecular dynamics with MP2 (for the athermal ground-state dynamics following internal conversion), coined (NA+BO)MD. The initial conditions were sampled from Born-Oppenheimer molecular dynamics coupled to a quantum thermostat. Our simulations indicate that the main photoproducts after 2 ps of dynamics are CO + cyclopropane (50%), CO + propene (10%), and ethene and ketene (34%). The photoexcited cyclobutanone in its second excited electronic state S2 can follow two pathways for its nonradiative decay: (i) a ring-opening in S2 and a subsequent rapid decay to the ground electronic state, where the photoproducts are formed, or (ii) a transfer through a closed-ring conical intersection to S1, where cyclobutanone ring opens and then funnels to the ground state. Lifetimes for the photoproduct and electronic populations were determined. We calculated a stationary MeV-UED signal [difference pair distribution function-ΔPDF(r)] for each (interpolated) pathway as well as a time-resolved signal [ΔPDF(r,t) and ΔI/I(s,t)] for the full swarm of (NA+BO)MD trajectories. Furthermore, our analysis provides time-independent basis functions that can be used to fit the time-dependent experimental UED signals [both ΔPDF(r,t) and ΔI/I(s,t)] and potentially recover the population of photoproducts. We also offer a detailed analysis of the limitations of our model and their potential impact on the predicted experimental signals.
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Affiliation(s)
- Jiří Janoš
- Department of Physical Chemistry, University of Chemistry and Technology, Technická 5, Prague 6 166 28, Czech Republic
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
| | | | - Daniel Hollas
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
| | - Petr Slavíček
- Department of Physical Chemistry, University of Chemistry and Technology, Technická 5, Prague 6 166 28, Czech Republic
| | - Basile F E Curchod
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
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11
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Figueira Nunes JP, Ibele LM, Pathak S, Attar AR, Bhattacharyya S, Boll R, Borne K, Centurion M, Erk B, Lin MF, Forbes RJG, Goff N, Hansen CS, Hoffmann M, Holland DMP, Ingle RA, Luo D, Muvva SB, Reid AH, Rouzée A, Rudenko A, Saha SK, Shen X, Venkatachalam AS, Wang X, Ware MR, Weathersby SP, Wilkin K, Wolf TJA, Xiong Y, Yang J, Ashfold MNR, Rolles D, Curchod BFE. Monitoring the Evolution of Relative Product Populations at Early Times during a Photochemical Reaction. J Am Chem Soc 2024; 146:4134-4143. [PMID: 38317439 PMCID: PMC10870701 DOI: 10.1021/jacs.3c13046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 01/10/2024] [Accepted: 01/10/2024] [Indexed: 02/07/2024]
Abstract
Identifying multiple rival reaction products and transient species formed during ultrafast photochemical reactions and determining their time-evolving relative populations are key steps toward understanding and predicting photochemical outcomes. Yet, most contemporary ultrafast studies struggle with clearly identifying and quantifying competing molecular structures/species among the emerging reaction products. Here, we show that mega-electronvolt ultrafast electron diffraction in combination with ab initio molecular dynamics calculations offer a powerful route to determining time-resolved populations of the various isomeric products formed after UV (266 nm) excitation of the five-membered heterocyclic molecule 2(5H)-thiophenone. This strategy provides experimental validation of the predicted high (∼50%) yield of an episulfide isomer containing a strained three-membered ring within ∼1 ps of photoexcitation and highlights the rapidity of interconversion between the rival highly vibrationally excited photoproducts in their ground electronic state.
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Affiliation(s)
| | - Lea Maria Ibele
- CNRS,
Institut de Chimie Physique UMR8000, Université
Paris-Saclay, Orsay, 9140, France
| | - Shashank Pathak
- J.R.
Macdonald Laboratory, Physics Department, Kansas State University, Manhattan, Kansas 66506, United States
| | - Andrew R. Attar
- SLAC
National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Surjendu Bhattacharyya
- J.R.
Macdonald Laboratory, Physics Department, Kansas State University, Manhattan, Kansas 66506, United States
| | | | - Kurtis Borne
- J.R.
Macdonald Laboratory, Physics Department, Kansas State University, Manhattan, Kansas 66506, United States
| | - Martin Centurion
- University
of Nebraska−Lincoln, Lincoln, Nebraska 68588, United States
| | - Benjamin Erk
- Deutsches
Elektronen Synchrotron DESY, Hamburg, 22607, Germany
| | - Ming-Fu Lin
- SLAC
National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Ruaridh J. G. Forbes
- SLAC
National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Nathan Goff
- Brown University, Providence, Rhode Island 02912, United States
| | | | - Matthias Hoffmann
- SLAC
National Accelerator Laboratory, Menlo Park, California 94025, United States
| | | | - Rebecca A. Ingle
- Department
of Chemistry, University College London, London, WC1H 0AJ, U.K.
| | - Duan Luo
- SLAC
National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Sri Bhavya Muvva
- University
of Nebraska−Lincoln, Lincoln, Nebraska 68588, United States
| | - Alexander H. Reid
- SLAC
National Accelerator Laboratory, Menlo Park, California 94025, United States
| | | | - Artem Rudenko
- J.R.
Macdonald Laboratory, Physics Department, Kansas State University, Manhattan, Kansas 66506, United States
| | - Sajib Kumar Saha
- University
of Nebraska−Lincoln, Lincoln, Nebraska 68588, United States
| | - Xiaozhe Shen
- SLAC
National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Anbu Selvam Venkatachalam
- J.R.
Macdonald Laboratory, Physics Department, Kansas State University, Manhattan, Kansas 66506, United States
| | - Xijie Wang
- SLAC
National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Matt R. Ware
- SLAC
National Accelerator Laboratory, Menlo Park, California 94025, United States
| | | | - Kyle Wilkin
- University
of Nebraska−Lincoln, Lincoln, Nebraska 68588, United States
| | - Thomas J. A. Wolf
- SLAC
National Accelerator Laboratory, Menlo Park, California 94025, United States
- Stanford
PULSE Institute, SLAC National Accelerator
Laboratory, Menlo
Park, California 94025, United States
| | - Yanwei Xiong
- University
of Nebraska−Lincoln, Lincoln, Nebraska 68588, United States
| | - Jie Yang
- SLAC
National Accelerator Laboratory, Menlo Park, California 94025, United States
| | | | - Daniel Rolles
- J.R.
Macdonald Laboratory, Physics Department, Kansas State University, Manhattan, Kansas 66506, United States
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12
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Siddiqui KM, Durham DB, Cropp F, Ji F, Paiagua S, Ophus C, Andresen NC, Jin L, Wu J, Wang S, Zhang X, You W, Murnane M, Centurion M, Wang X, Slaughter DS, Kaindl RA, Musumeci P, Minor AM, Filippetto D. Relativistic ultrafast electron diffraction at high repetition rates. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2023; 10:064302. [PMID: 38058995 PMCID: PMC10697722 DOI: 10.1063/4.0000203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 11/08/2023] [Indexed: 12/08/2023]
Abstract
The ability to resolve the dynamics of matter on its native temporal and spatial scales constitutes a key challenge and convergent theme across chemistry, biology, and materials science. The last couple of decades have witnessed ultrafast electron diffraction (UED) emerge as one of the forefront techniques with the sensitivity to resolve atomic motions. Increasingly sophisticated UED instruments are being developed that are aimed at increasing the beam brightness in order to observe structural signatures, but so far they have been limited to low average current beams. Here, we present the technical design and capabilities of the HiRES (High Repetition-rate Electron Scattering) instrument, which blends relativistic electrons and high repetition rates to achieve orders of magnitude improvement in average beam current compared to the existing state-of-the-art instruments. The setup utilizes a novel electron source to deliver femtosecond duration electron pulses at up to MHz repetition rates for UED experiments. Instrument response function of sub-500 fs is demonstrated with < 100 fs time resolution targeted in future. We provide example cases of diffraction measurements on solid-state and gas-phase samples, including both micro- and nanodiffraction (featuring 100 nm beam size) modes, which showcase the potential of the instrument for novel UED experiments.
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Affiliation(s)
- K. M. Siddiqui
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | | | | | - F. Ji
- Accelerator Technology and Applied Physics Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - S. Paiagua
- Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720, USA
| | - C. Ophus
- National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - N. C. Andresen
- Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - L. Jin
- Department of Materials Science and Engineering, University of California at Berkeley, Berkeley, California 94720, USA
| | - J. Wu
- Department of Materials Science and Engineering, University of California at Berkeley, Berkeley, California 94720, USA
| | - S. Wang
- Department of Electrical Engineering and Computer Sciences, University of California at Berkeley, Berkeley, California 94720, USA
| | - X. Zhang
- Department of Mechanical Engineering, University of California at Berkeley, Berkeley, California 94720, USA
| | - W. You
- Department of Physics and JILA, University of Colorado and NIST, Boulder, Colorado 80309, USA
| | - M. Murnane
- Department of Physics and JILA, University of Colorado and NIST, Boulder, Colorado 80309, USA
| | - M. Centurion
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - X. Wang
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - D. S. Slaughter
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, California 94720, USA
| | | | - P. Musumeci
- Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095, USA
| | | | - D. Filippetto
- Accelerator Technology and Applied Physics Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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13
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Champenois EG, List NH, Ware M, Britton M, Bucksbaum PH, Cheng X, Centurion M, Cryan JP, Forbes R, Gabalski I, Hegazy K, Hoffmann MC, Howard AJ, Ji F, Lin MF, Nunes JPF, Shen X, Yang J, Wang X, Martinez TJ, Wolf TJA. Femtosecond Electronic and Hydrogen Structural Dynamics in Ammonia Imaged with Ultrafast Electron Diffraction. PHYSICAL REVIEW LETTERS 2023; 131:143001. [PMID: 37862660 DOI: 10.1103/physrevlett.131.143001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 07/06/2023] [Accepted: 08/12/2023] [Indexed: 10/22/2023]
Abstract
Directly imaging structural dynamics involving hydrogen atoms by ultrafast diffraction methods is complicated by their low scattering cross sections. Here we demonstrate that megaelectronvolt ultrafast electron diffraction is sufficiently sensitive to follow hydrogen dynamics in isolated molecules. In a study of the photodissociation of gas phase ammonia, we simultaneously observe signatures of the nuclear and corresponding electronic structure changes resulting from the dissociation dynamics in the time-dependent diffraction. Both assignments are confirmed by ab initio simulations of the photochemical dynamics and the resulting diffraction observable. While the temporal resolution of the experiment is insufficient to resolve the dissociation in time, our results represent an important step towards the observation of proton dynamics in real space and time.
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Affiliation(s)
- Elio G Champenois
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Nanna H List
- Department of Chemistry, KTH Royal Institute of Technology, SE-10044 Stockholm, Sweden
| | - Matthew Ware
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Mathew Britton
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
- Department of Physics, Stanford University, Stanford, California 94305, USA
| | - Philip H Bucksbaum
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
- Department of Physics, Stanford University, Stanford, California 94305, USA
| | - Xinxin Cheng
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Martin Centurion
- Department of Physics and Astronomy, University of Nebraska Lincoln, Lincoln, Nebraska 68588, USA
| | - James P Cryan
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Ruaridh Forbes
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Ian Gabalski
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
- Department of Applied Physics, Stanford University, Stanford, California 94305, USA
| | - Kareem Hegazy
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
- Department of Physics, Stanford University, Stanford, California 94305, USA
| | | | - Andrew J Howard
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
- Department of Applied Physics, Stanford University, Stanford, California 94305, USA
| | - Fuhao Ji
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Ming-Fu Lin
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - J Pedro F Nunes
- Department of Physics and Astronomy, University of Nebraska Lincoln, Lincoln, Nebraska 68588, USA
| | - Xiaozhe Shen
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Jie Yang
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
- Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Xijie Wang
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Todd J Martinez
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
| | - Thomas J A Wolf
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
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14
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Liu Y, Sanchez DM, Ware MR, Champenois EG, Yang J, Nunes JPF, Attar A, Centurion M, Cryan JP, Forbes R, Hegazy K, Hoffmann MC, Ji F, Lin MF, Luo D, Saha SK, Shen X, Wang XJ, Martínez TJ, Wolf TJA. Rehybridization dynamics into the pericyclic minimum of an electrocyclic reaction imaged in real-time. Nat Commun 2023; 14:2795. [PMID: 37202402 DOI: 10.1038/s41467-023-38513-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 04/28/2023] [Indexed: 05/20/2023] Open
Abstract
Electrocyclic reactions are characterized by the concerted formation and cleavage of both σ and π bonds through a cyclic structure. This structure is known as a pericyclic transition state for thermal reactions and a pericyclic minimum in the excited state for photochemical reactions. However, the structure of the pericyclic geometry has yet to be observed experimentally. We use a combination of ultrafast electron diffraction and excited state wavepacket simulations to image structural dynamics through the pericyclic minimum of a photochemical electrocyclic ring-opening reaction in the molecule α-terpinene. The structural motion into the pericyclic minimum is dominated by rehybridization of two carbon atoms, which is required for the transformation from two to three conjugated π bonds. The σ bond dissociation largely happens after internal conversion from the pericyclic minimum to the electronic ground state. These findings may be transferrable to electrocyclic reactions in general.
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Affiliation(s)
- Y Liu
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY, 11790, USA
| | - D M Sanchez
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
- Department of Chemistry, Stanford University, 333 Campus Drive, Stanford, CA, 94305, USA
- Design Physics Division, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - M R Ware
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - E G Champenois
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - J Yang
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
- Center of Basic Molecular Science, Department of Chemistry, Mong Man Wai Building of Science and Technology, S-1027 Tsinghua University, Beijing, China
| | - J P F Nunes
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Theodore Jorgensen Hall 208, 855 N 16th Street, Lincoln, NE, 68588, USA
- Diamond Light Source, Harwell Science Campus, Fermi Ave, Didcot, OX11 0DE, UK
| | - A Attar
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - M Centurion
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Theodore Jorgensen Hall 208, 855 N 16th Street, Lincoln, NE, 68588, USA
| | - J P Cryan
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - R Forbes
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - K Hegazy
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - M C Hoffmann
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - F Ji
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - M-F Lin
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - D Luo
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - S K Saha
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Theodore Jorgensen Hall 208, 855 N 16th Street, Lincoln, NE, 68588, USA
| | - X Shen
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - X J Wang
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - T J Martínez
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA.
- Department of Chemistry, Stanford University, 333 Campus Drive, Stanford, CA, 94305, USA.
| | - T J A Wolf
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA.
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15
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Alberdi Esuain B, Hwang JG, Neumann A, Kamps T. Novel approach to push the limit of temporal resolution in ultrafast electron diffraction accelerators. Sci Rep 2022; 12:13365. [PMID: 35922438 PMCID: PMC9349226 DOI: 10.1038/s41598-022-17453-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 07/26/2022] [Indexed: 11/19/2022] Open
Abstract
Ultrafast electron diffraction techniques that employ relativistic electrons as a probe have been in the spotlight as a key technology for visualizing structural dynamics which take place on a time scale of a few femtoseconds to hundreds femtoseconds. These applications highly demand not only extreme beam quality in 6-D phase space such as a few nanometer transverse emittances and femtosecond duration but also equivalent beam stability. Although these utmost requirements have been demonstrated by a compact setup with a high-gradient electron gun with state-of-the-art laser technologies, this approach is fundamentally restricted by its nature for compressing the electrons in a short distance by a ballistic bunching method. Here, we propose a new methodology that pushes the limit of timing jitter beyond the state-of-the-art by utilizing consecutive RF cavities. This layout already exists in reality for energy recovery linear accelerator demonstrators. Furthermore, the demonstrators are able to provide MHz repetition rates, which are out of reach for most conventional high-gradient electron guns.
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Affiliation(s)
- Beñat Alberdi Esuain
- Helmholtz-Zentrum Berlin (HZB), Hahn-Meitner-Platz 1, 14109, Berlin, Germany.
- Humboldt-Universität zu Berlin Institut für Physik, Newton-Straße 15, 12489, Berlin, Germany.
| | - Ji-Gwang Hwang
- Helmholtz-Zentrum Berlin (HZB), Hahn-Meitner-Platz 1, 14109, Berlin, Germany
| | - Axel Neumann
- Helmholtz-Zentrum Berlin (HZB), Hahn-Meitner-Platz 1, 14109, Berlin, Germany
| | - Thorsten Kamps
- Helmholtz-Zentrum Berlin (HZB), Hahn-Meitner-Platz 1, 14109, Berlin, Germany
- Humboldt-Universität zu Berlin Institut für Physik, Newton-Straße 15, 12489, Berlin, Germany
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16
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Razmus WO, Acheson K, Bucksbaum P, Centurion M, Champenois E, Gabalski I, Hoffman MC, Howard A, Lin MF, Liu Y, Nunes P, Saha S, Shen X, Ware M, Warne EM, Weinacht T, Wilkin K, Yang J, Wolf TJA, Kirrander A, Minns RS, Forbes R. Multichannel photodissociation dynamics in CS 2 studied by ultrafast electron diffraction. Phys Chem Chem Phys 2022; 24:15416-15427. [PMID: 35707953 DOI: 10.1039/d2cp01268e] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The structural dynamics of photoexcited gas-phase carbon disulfide (CS2) molecules are investigated using ultrafast electron diffraction. The dynamics were triggered by excitation of the optically bright 1B2(1Σu+) state by an ultraviolet femtosecond laser pulse centred at 200 nm. In accordance with previous studies, rapid vibrational motion facilitates a combination of internal conversion and intersystem crossing to lower-lying electronic states. Photodissociation via these electronic manifolds results in the production of CS fragments in the electronic ground state and dissociated singlet and triplet sulphur atoms. The structural dynamics are extracted from the experiment using a trajectory-fitting filtering approach, revealing the main characteristics of the singlet and triplet dissociation pathways. Finally, the effect of the time-resolution on the experimental signal is considered and an outlook to future experiments provided.
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Affiliation(s)
- Weronika O Razmus
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
| | - Kyle Acheson
- EaStCHEM, School of Chemistry and Centre for Science at Extreme Conditions, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, UK.
| | - Philip Bucksbaum
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Martin Centurion
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - Elio Champenois
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Ian Gabalski
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Matthias C Hoffman
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
| | - Andrew Howard
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Ming-Fu Lin
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
| | - Yusong Liu
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA
| | - Pedro Nunes
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - Sajib Saha
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - Xiaozhe Shen
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Matthew Ware
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Emily M Warne
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
| | - Thomas Weinacht
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA
| | - Kyle Wilkin
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - Jie Yang
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Thomas J A Wolf
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Adam Kirrander
- EaStCHEM, School of Chemistry and Centre for Science at Extreme Conditions, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, UK.
| | - Russell S Minns
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
| | - Ruaridh Forbes
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
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17
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Zhang M, Guo Z, Mi X, Li Z, Liu Y. Ultrafast Imaging of Molecular Dynamics Using Ultrafast Low-Frequency Lasers, X-ray Free Electron Lasers, and Electron Pulses. J Phys Chem Lett 2022; 13:1668-1680. [PMID: 35147438 DOI: 10.1021/acs.jpclett.1c03916] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The requirement of high space-time resolution and brightness is a great challenge for imaging atomic motion and making molecular movies. Important breakthroughs in ultrabright tabletop laser, X-ray, and electron sources have enabled the direct imaging of evolving molecular structures in chemical processes, and recent experimental advances in preparing ultrafast laser and electron pulses resulted in molecular imaging with femtosecond time resolution. This Perspective presents an overview of the versatile imaging methods of molecular dynamics. High-order harmonic generation imaging and photoelectron diffraction imaging are based on laser-induced ionization and rescattering processes. Coulomb explosion imaging retrieves molecular structural information by detecting the momentum vectors of fragmented ions. Diffraction imaging encodes molecular structural and electronic information in reciprocal space. We also present various applications of these ultrafast imaging methods in resolving laser-induced nuclear and electronic dynamics.
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Affiliation(s)
- Ming Zhang
- State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China
| | - Zhengning Guo
- State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China
| | - Xiaoyu Mi
- State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China
| | - Zheng Li
- State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
- Yangtze Delta Institute of Optoelectronics, Peking University, Nantong 226010, China
| | - Yunquan Liu
- State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
- Center for Applied Physics and Technology, HEDPS, Peking University, Beijing 100871, China
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18
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Abstract
Photoexcited molecules convert light into chemical and mechanical energy through changes in electronic and nuclear structure that take place on femtosecond timescales. Gas phase ultrafast electron diffraction (GUED) is an ideal tool to probe the nuclear geometry evolution of the molecules and complements spectroscopic methods that are mostly sensitive to the electronic state. GUED is a passive probing tool that does not alter the molecular properties during the probing process and is sensitive to the spatial distribution of charge in the molecule, including both electrons and nuclei. Improvements in temporal resolution have enabled GUED to capture coherent nuclear motions in molecules in the excited and ground electronic states with femtosecond and subangstrom resolution. Here we present the basic theory of GUED and explain what information is encoded in the diffraction signal, review how GUED has been used to observe coherent structural dynamics in recent experiments, and discuss the advantages and limitations of the method. 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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Affiliation(s)
- Martin Centurion
- Department of Physics and Astronomy, University of Nebraska, Lincoln, Nebraska, USA;
| | - Thomas J A Wolf
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California, USA;
| | - Jie Yang
- Center of Basic Molecular Science, Department of Chemistry, Tsinghua University, China;
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19
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Wang SJ, Daněk J, Blaga CI, DiMauro LF, Biegert J, Lin CD. Two-dimensional retrieval methods for ultrafast imaging of molecular structure using laser-induced electron diffraction. J Chem Phys 2021; 155:164104. [PMID: 34717362 DOI: 10.1063/5.0064761] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Molecular structural retrieval based on electron diffraction has been proposed to determine the atomic positions of molecules with sub-angstrom spatial and femtosecond temporal resolutions. Given its success on small molecular systems, in this work, we point out that the accuracy of structure retrieval is constrained by the availability of a wide range of experimental data in the momentum space in all molecular systems. To mitigate the limitations, for laser-induced electron diffraction, here we retrieve molecular structures using two-dimensional (energy and angle) electron momentum spectra in the laboratory frame for a number of small molecular systems, which have previously been studied with 1D methods. Compared to the conventional single-energy or single-angle analysis, our 2D methods effectively expand the momentum range of the measured data. Besides utilization of the 2D data, two complementary methods are developed for consistency check on the retrieved results. The 2D nature of our methods also offers a way of estimating the error from retrieval, which has never been explored before. Comparing with results from prior experiments, our findings show evidence that our 2D methods outperform the conventional 1D methods. Paving the way to the retrieval of large molecular systems, in which their tunneling ionization rates are challenging to obtain, we estimate the error of using the isotropic model in place of including the orientation-dependent ionization rate.
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Affiliation(s)
- Su-Ju Wang
- J. R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506, USA
| | - Jiří Daněk
- J. R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506, USA
| | - Cosmin I Blaga
- J. R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506, USA
| | - Louis F DiMauro
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - Jens Biegert
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - C D Lin
- J. R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506, USA
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20
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Champenois EG, Sanchez DM, Yang J, Figueira Nunes JP, Attar A, Centurion M, Forbes R, Gühr M, Hegazy K, Ji F, Saha SK, Liu Y, Lin MF, Luo D, Moore B, Shen X, Ware MR, Wang XJ, Martínez TJ, Wolf TJA. Conformer-specific photochemistry imaged in real space and time. Science 2021; 374:178-182. [PMID: 34618569 DOI: 10.1126/science.abk3132] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- E G Champenois
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - D M Sanchez
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA.,Department of Chemistry, Stanford University, Stanford, CA, USA
| | - J Yang
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA.,SLAC National Accelerator Laboratory, Menlo Park, CA, USA.,Center of Basic Molecular Science, Department of Chemistry, Tsinghua University, Beijing, China
| | - J P Figueira Nunes
- Department of Physics and Astronomy, University of Nebraska, Lincoln, NE, USA
| | - A Attar
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - M Centurion
- Department of Physics and Astronomy, University of Nebraska, Lincoln, NE, USA
| | - R Forbes
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - M Gühr
- Institut für Physik und Astronomie, Universität Potsdam, Potsdam, Germany
| | - K Hegazy
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA.,Department of Physics, Stanford University, Stanford, CA, USA
| | - F Ji
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - S K Saha
- Department of Physics and Astronomy, University of Nebraska, Lincoln, NE, USA
| | - Y Liu
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY, USA
| | - M-F Lin
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - D Luo
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - B Moore
- Department of Physics and Astronomy, University of Nebraska, Lincoln, NE, USA
| | - X Shen
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - M R Ware
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - X J Wang
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - T J Martínez
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA.,Department of Chemistry, Stanford University, Stanford, CA, USA
| | - T J A Wolf
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
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21
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Suzuki T. Spiers Memorial Lecture: Introduction to ultrafast spectroscopy and imaging of photochemical reactions. Faraday Discuss 2021; 228:11-38. [PMID: 33876168 DOI: 10.1039/d1fd00015b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A brief overview is presented on ultrafast spectroscopy and imaging of photochemical reactions by highlighting several experimental studies reported in the last five years. A particular focus is placed on new experiments performed using high-order harmonic generation, X-ray free electron lasers, and relativistic electron beams. Exploration of fundamental chemical reaction dynamics using these advanced experimental methodologies is in an early stage, and exciting new research opportunities await in this rapidly expanding and advancing research field. At the same time, there is no experimental methodology that provides all aspects of the electronic and structural dynamics in a single experiment, and investigations using different methodologies with various perspectives need to be considered in a comprehensive manner.
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Affiliation(s)
- Toshinori Suzuki
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
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22
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Daoud H, Miller RJD. Utilizing relativistic time dilation for time-resolved studies. J Chem Phys 2021; 154:111107. [PMID: 33752362 DOI: 10.1063/5.0037862] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Time-resolved studies have so far relied on rapidly triggering a photo-induced dynamic in chemical or biological ions or molecules and subsequently probing them with a beam of fast moving photons or electrons that crosses the studied samples in a short period of time. Hence, the time resolution of the signal is mainly set by the pulse duration of the pump and probe pulses. In this paper, we propose a different approach to this problem that has the potential to consistently achieve orders of magnitude higher time resolutions than what is possible with laser technology or electron beam compression methods. Our proposed approach relies on accelerating the sample to a high speed to achieve relativistic time dilation. Probing the time-dilated sample would open up previously inaccessible time resolution domains.
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Affiliation(s)
- Hazem Daoud
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
| | - R J Dwayne Miller
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
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23
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Sanchez A, Amini K, Wang SJ, Steinle T, Belsa B, Danek J, Le AT, Liu X, Moshammer R, Pfeifer T, Richter M, Ullrich J, Gräfe S, Lin CD, Biegert J. Molecular structure retrieval directly from laboratory-frame photoelectron spectra in laser-induced electron diffraction. Nat Commun 2021; 12:1520. [PMID: 33750798 PMCID: PMC7943781 DOI: 10.1038/s41467-021-21855-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 02/17/2021] [Indexed: 01/31/2023] Open
Abstract
Ubiquitous to most molecular scattering methods is the challenge to retrieve bond distance and angle from the scattering signals since this requires convergence of pattern matching algorithms or fitting methods. This problem is typically exacerbated when imaging larger molecules or for dynamic systems with little a priori knowledge. Here, we employ laser-induced electron diffraction (LIED) which is a powerful means to determine the precise atomic configuration of an isolated gas-phase molecule with picometre spatial and attosecond temporal precision. We introduce a simple molecular retrieval method, which is based only on the identification of critical points in the oscillating molecular interference scattering signal that is extracted directly from the laboratory-frame photoelectron spectrum. The method is compared with a Fourier-based retrieval method, and we show that both methods correctly retrieve the asymmetrically stretched and bent field-dressed configuration of the asymmetric top molecule carbonyl sulfide (OCS), which is confirmed by our quantum-classical calculations.
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Affiliation(s)
- A Sanchez
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - K Amini
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - S-J Wang
- Department of Physics, J. R. Macdonald Laboratory, Kansas State University, Manhattan, KS, USA
| | - T Steinle
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - B Belsa
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - J Danek
- Department of Physics, J. R. Macdonald Laboratory, Kansas State University, Manhattan, KS, USA
| | - A T Le
- Department of Physics, J. R. Macdonald Laboratory, Kansas State University, Manhattan, KS, USA
- Department of Physics, Missouri University of Science and Technology, Rolla, MO, USA
| | - X Liu
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - R Moshammer
- Max-Planck-Institut für Kernphysik, Heidelberg, Germany
| | - T Pfeifer
- Max-Planck-Institut für Kernphysik, Heidelberg, Germany
| | - M Richter
- Physikalisch-Technische Bundesanstalt, Braunschweig, Germany
| | - J Ullrich
- Max-Planck-Institut für Kernphysik, Heidelberg, Germany
- Physikalisch-Technische Bundesanstalt, Braunschweig, Germany
| | - S Gräfe
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-Universität Jena, Jena, Germany
| | - C D Lin
- Department of Physics, J. R. Macdonald Laboratory, Kansas State University, Manhattan, KS, USA
| | - J Biegert
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Barcelona, Spain.
- ICREA, Barcelona, Spain.
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24
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Ma ZR, Qi FF, Xiang D. Probing molecular dynamics with ultrafast electron diffraction. CHINESE J CHEM PHYS 2021. [DOI: 10.1063/1674-0068/cjcp2012208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Zhuo-ran Ma
- Key Laboratory for Laser Plasmas (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
- Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Feng-feng Qi
- Key Laboratory for Laser Plasmas (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
- Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Dao Xiang
- Key Laboratory for Laser Plasmas (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
- Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240, China
- Tsung-Dao Lee Institute, Shanghai 200240, China
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25
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Belsa B, Amini K, Liu X, Sanchez A, Steinle T, Steinmetzer J, Le AT, Moshammer R, Pfeifer T, Ullrich J, Moszynski R, Lin CD, Gräfe S, Biegert J. Laser-induced electron diffraction of the ultrafast umbrella motion in ammonia. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2021; 8:014301. [PMID: 34026922 PMCID: PMC8121549 DOI: 10.1063/4.0000046] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 12/25/2020] [Indexed: 06/12/2023]
Abstract
Visualizing molecular transformations in real-time requires a structural retrieval method with Ångström spatial and femtosecond temporal atomic resolution. Imaging of hydrogen-containing molecules additionally requires an imaging method sensitive to the atomic positions of hydrogen nuclei, with most methods possessing relatively low sensitivity to hydrogen scattering. Laser-induced electron diffraction (LIED) is a table-top technique that can image ultrafast structural changes of gas-phase polyatomic molecules with sub-Ångström and femtosecond spatiotemporal resolution together with relatively high sensitivity to hydrogen scattering. Here, we image the umbrella motion of an isolated ammonia molecule (NH3) following its strong-field ionization. Upon ionization of a neutral ammonia molecule, the ammonia cation (NH3 +) undergoes an ultrafast geometrical transformation from a pyramidal ( Φ HNH = 107 ° ) to planar ( Φ HNH = 120 ° ) structure in approximately 8 femtoseconds. Using LIED, we retrieve a near-planar ( Φ HNH = 117 ± 5 ° ) field-dressed NH3 + molecular structure 7.8 - 9.8 femtoseconds after ionization. Our measured field-dressed NH3 + structure is in excellent agreement with our calculated equilibrium field-dressed structure using quantum chemical ab initio calculations.
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Affiliation(s)
- B. Belsa
- ICFO—Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | | | - X. Liu
- ICFO—Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - A. Sanchez
- ICFO—Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - T. Steinle
- ICFO—Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - J. Steinmetzer
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-Universität Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - A. T. Le
- Department of Physics, Missouri University of Science and Technology, Rolla, Missouri 65409, USA
| | - R. Moshammer
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - T. Pfeifer
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | | | - R. Moszynski
- Department of Chemistry, University of Warsaw, 02-093 Warsaw, Poland
| | - C. D. Lin
- Department of Physics, J. R. Macdonald Laboratory, Kansas State University, Manhattan, Kansas 66506-2604, USA
| | - S. Gräfe
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-Universität Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - J. Biegert
- Author to whom correspondence should be addressed:
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26
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Yang J, Zhu X, F Nunes JP, Yu JK, Parrish RM, Wolf TJA, Centurion M, Gühr M, Li R, Liu Y, Moore B, Niebuhr M, Park S, Shen X, Weathersby S, Weinacht T, Martinez TJ, Wang X. Simultaneous observation of nuclear and electronic dynamics by ultrafast electron diffraction. Science 2020; 368:885-889. [PMID: 32439793 DOI: 10.1126/science.abb2235] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Accepted: 04/03/2020] [Indexed: 01/02/2023]
Abstract
Simultaneous observation of nuclear and electronic motion is crucial for a complete understanding of molecular dynamics in excited electronic states. It is challenging for a single experiment to independently follow both electronic and nuclear dynamics at the same time. Here we show that ultrafast electron diffraction can be used to simultaneously record both electronic and nuclear dynamics in isolated pyridine molecules, naturally disentangling the two components. Electronic state changes (S1→S0 internal conversion) were reflected by a strong transient signal in small-angle inelastic scattering, and nuclear structural changes (ring puckering) were monitored by large-angle elastic diffraction. Supported by ab initio nonadiabatic molecular dynamics and diffraction simulations, our experiment provides a clear view of the interplay between electronic and nuclear dynamics of the photoexcited pyridine molecule.
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Affiliation(s)
- Jie Yang
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA. .,Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Xiaolei Zhu
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA.,Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA.,Department of Chemistry, Stanford University, Stanford, CA, USA
| | - J Pedro F Nunes
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Jimmy K Yu
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA.,Department of Chemistry, Stanford University, Stanford, CA, USA.,Biophysics Program, Stanford University, Stanford, CA, USA
| | - Robert M Parrish
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA.,Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA.,Department of Chemistry, Stanford University, Stanford, CA, USA
| | - Thomas J A Wolf
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA.,Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Martin Centurion
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Markus Gühr
- Institut für Physik und Astronomie, Universität Potsdam, Potsdam, Germany
| | - Renkai Li
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Yusong Liu
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY, USA
| | - Bryan Moore
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Mario Niebuhr
- Institut für Physik und Astronomie, Universität Potsdam, Potsdam, Germany
| | - Suji Park
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Xiaozhe Shen
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | | | - Thomas Weinacht
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY, USA
| | - Todd J Martinez
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA. .,Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA.,Department of Chemistry, Stanford University, Stanford, CA, USA
| | - Xijie Wang
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA.
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27
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Abstract
Time-resolved electron microscopy is based on the excitation of a sample by pulsed laser radiation and its probing by synchronized photoelectron bunches in the electron microscope column. With femtosecond lasers, if probing pulses with a small number of electrons—in the limit, single-electron wave packets—are used, the stroboscopic regime enables ultrahigh spatiotemporal resolution to be obtained, which is not restricted by the Coulomb repulsion of electrons. This review article presents the current state of the ultrafast electron microscopy (UEM) method for detecting the structural dynamics of matter in the time range from picoseconds to attoseconds. Moreover, in the imaging mode, the spatial resolution lies, at best, in the subnanometer range, which limits the range of observation of structural changes in the sample. The ultrafast electron diffraction (UED), which created the methodological basis for the development of UEM, has opened the possibility of creating molecular movies that show the behavior of the investigated quantum system in the space-time continuum with details of sub-Å spatial resolution. Therefore, this review on the development of UEM begins with a description of the main achievements of UED, which formed the basis for the creation and further development of the UEM method. A number of recent experiments are presented to illustrate the potential of the UEM method.
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28
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Abstract
Electron diffraction correlates the excited-state decay of pyridine with its ring distortion
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Affiliation(s)
- Wolfgang Domcke
- Department of Chemistry of the Technical University of Munich, Munich, Germany.
| | - Andrzej L Sobolewski
- Institute of Physics of the Polish Academy of Sciences in Warsaw, Warsaw, Poland
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29
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Ma L, Yong H, Geiser JD, Moreno Carrascosa A, Goff N, Weber PM. Ultrafast x-ray and electron scattering of free molecules: A comparative evaluation. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2020; 7:034102. [PMID: 32637459 PMCID: PMC7316516 DOI: 10.1063/4.0000010] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 06/08/2020] [Indexed: 05/09/2023]
Abstract
Resolving gas phase molecular motions with simultaneous spatial and temporal resolution is rapidly coming within the reach of x-ray Free Electron Lasers (XFELs) and Mega-electron-Volt (MeV) electron beams. These two methods enable scattering experiments that have yielded fascinating new results, and while both are important methods for determining transient molecular structures in photochemical reactions, it is important to understand their relative merits. In the present study, we evaluate the respective scattering cross sections of the two methods and simulate their ability to determine excited state molecular structures in light of currently existing XFEL and MeV source parameters. Using the example of optically excited N-methyl morpholine and simulating the scattering patterns with shot noise, we find that the currently achievable signals are superior with x-ray scattering for equal samples and on a per-shot basis and that x-ray scattering requires fewer detected signal counts for an equal fidelity structure determination. Importantly, within the independent atom model, excellent structure determinations can be achieved for scattering vectors only to about 5 Å-1, leaving larger scattering vector ranges for investigating vibrational motions and wavepackets. Electron scattering has a comparatively higher sensitivity toward hydrogen atoms, which may point to applications where electron scattering is inherently the preferred choice, provided that excellent signals can be achieved at large scattering angles that are currently difficult to access.
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Affiliation(s)
- Lingyu Ma
- Brown University, Department of Chemistry, Providence, Rhode Island 02912, USA
| | - Haiwang Yong
- Brown University, Department of Chemistry, Providence, Rhode Island 02912, USA
| | - Joseph D. Geiser
- Brown University, Department of Chemistry, Providence, Rhode Island 02912, USA
| | | | - Nathan Goff
- Brown University, Department of Chemistry, Providence, Rhode Island 02912, USA
| | - Peter M. Weber
- Brown University, Department of Chemistry, Providence, Rhode Island 02912, USA
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