1
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Shu Y, Truhlar DG. Generalized Semiclassical Ehrenfest Method: A Route to Wave Function-Free Photochemistry and Nonadiabatic Dynamics with Only Potential Energies and Gradients. J Chem Theory Comput 2024; 20:4396-4426. [PMID: 38819014 DOI: 10.1021/acs.jctc.4c00424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2024]
Abstract
We reconsider recent methods by which direct dynamics calculations of electronically nonadiabatic processes can be carried out while requiring only adiabatic potential energies and their gradients. We show that these methods can be understood in terms of a new generalization of the well-known semiclassical Ehrenfest method. This is convenient because it eliminates the need to evaluate electronic wave functions and their matrix elements along the mixed quantum-classical trajectories. The new approximations and procedures enabling this advance are the curvature-driven approximation to the time-derivative coupling, the generalized semiclassical Ehrenfest method, and a new gradient correction scheme called the time-derivative matrix (TDM) scheme. When spin-orbit coupling is present, one can carry out dynamics calculations in the fully adiabatic basis using potential energies and gradients calculated without spin-orbit coupling plus the spin-orbit coupling matrix elements. Even when spin-orbit coupling is neglected, the method is useful because it allows calculations by electronic structure methods for which nonadiabatic coupling vectors are unavailable. In order to place the new considerations in context, the article starts out with a review of background material on trajectory surface hopping, the semiclassical Ehrenfest scheme, and methods for incorporating decoherence. We consider both internal conversion and intersystem crossing. We also review several examples from our group of successful applications of the curvature-driven approximation.
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Affiliation(s)
- Yinan Shu
- Department of Chemistry, Chemical Theory Center, and Minnesota Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
| | - Donald G Truhlar
- Department of Chemistry, Chemical Theory Center, and Minnesota Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
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2
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Hutton L, Moreno Carrascosa A, Prentice AW, Simmermacher M, Runeson JE, Paterson MJ, Kirrander A. Using a multistate mapping approach to surface hopping to predict the ultrafast electron diffraction signal of gas-phase cyclobutanone. J Chem Phys 2024; 160:204307. [PMID: 38814011 DOI: 10.1063/5.0203667] [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: 05/05/2024] [Indexed: 05/31/2024] Open
Abstract
Using the recently developed multistate mapping approach to surface hopping (multistate MASH) method combined with SA(3)-CASSCF(12,12)/aug-cc-pVDZ electronic structure calculations, the gas-phase isotropic ultrafast electron diffraction (UED) of cyclobutanone is predicted and analyzed. After excitation into the n-3s Rydberg state (S2), cyclobutanone can relax through two S2/S1 conical intersections, one characterized by compression of the CO bond and the other by dissociation of the α-CC bond. Subsequent transfer into the ground state (S0) is then achieved via two additional S1/S0 conical intersections that lead to three reaction pathways: α ring-opening, ethene/ketene production, and CO liberation. The isotropic gas-phase UED signal is predicted from the multistate MASH simulations, allowing for a direct comparison to the experimental data. This work, which is a contribution to the cyclobutanone prediction challenge, facilitates the identification of the main photoproducts in the UED signal and thereby emphasizes the importance of dynamics simulations for the interpretation of ultrafast experiments.
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Affiliation(s)
- Lewis Hutton
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Andrés Moreno Carrascosa
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Andrew W Prentice
- Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Mats Simmermacher
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Johan E Runeson
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Martin J Paterson
- Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Adam Kirrander
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, United Kingdom
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3
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Acheson K, Kirrander A. Automatic Clustering of Excited-State Trajectories: Application to Photoexcited Dynamics. J Chem Theory Comput 2023; 19:6126-6138. [PMID: 37703098 PMCID: PMC10536988 DOI: 10.1021/acs.jctc.3c00776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Indexed: 09/14/2023]
Abstract
We introduce automatic clustering as a computationally efficient tool for classifying and interpreting trajectories from simulations of photo-excited dynamics. Trajectories are treated as time-series data, with the features for clustering selected by variance mapping of normalized data. The L2-norm and dynamic time warping are proposed as suitable similarity measures for calculating the distance matrices, and these are clustered using the unsupervised density-based DBSCAN algorithm. The silhouette coefficient and the number of trajectories classified as noise are used as quality measures for the clustering. The ability of clustering to provide rapid overview of large and complex trajectory data sets, and its utility for extracting chemical and physical insight, is demonstrated on trajectories corresponding to the photochemical ring-opening reaction of 1,3-cyclohexadiene, noting that the clustering can be used to generate reduced dimensionality representations in an unbiased manner.
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Affiliation(s)
- Kyle Acheson
- EaStCHEM,
School of Chemistry and Centre for Science at Extreme Conditions, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, U.K.
- Department
of Chemistry, University of Warwick, Coventry CV4 7AL, U.K.
| | - Adam Kirrander
- Physical
and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
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4
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Bertram L, Weber PM, Kirrander A. Mapping the photochemistry of cyclopentadiene: from theory to ultrafast X-ray scattering. Faraday Discuss 2023; 244:269-293. [PMID: 37132432 DOI: 10.1039/d2fd00176d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
The photoinduced ring-conversion reaction when cyclopentadiene (CP) is excited at 5.10 eV is simulated using surface-hopping semiclassical trajectories with XMS(3)-CASPT2(4,4)/cc-pVDZ electronic structure theory. In addition, PBE0/def2-SV(P) is employed for ground state propagation of the trajectories. The dynamics is propagated for 10 ps, mapping both the nonadiabatic short-time dynamics (<300 fs) and the increasingly statistical dynamics on the electronic ground state. The short-time dynamics yields a mixture of hot CP and bicyclo[2.1.0]pentene (BP), with the two products reached via different regions of the same conical intersection seam. On the ground state, we observe slow conversion from BP to CP which is modelled by RRKM theory with a transition state determined using PBE0/def2-TZVP. The CP products are furthermore associated with ground state hydrogen shifts and some H-atom dissociation. Finally, the prospects for detailed experimental mapping using novel ultrafast X-ray scattering experiments are discussed and observables for such experiments are predicted. In particular, we assess the possibility of retrieving electronic states and their populations alongside the structural dynamics.
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Affiliation(s)
- Lauren Bertram
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QZ, UK.
| | - Peter M Weber
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Adam Kirrander
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QZ, UK.
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5
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Acheson K, Kirrander A. Robust Inversion of Time-Resolved Data via Forward-Optimization in a Trajectory Basis. J Chem Theory Comput 2023; 19:2721-2734. [PMID: 37129988 DOI: 10.1021/acs.jctc.2c01113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
An inversion method for time-resolved data from ultrafast experiments is introduced, based on forward-optimization in a trajectory basis. The method is applied to experimental data from X-ray scattering of the photochemical ring-opening reaction of 1,3-cyclohexadiene and electron diffraction of the photodissociation of CS2. In each case, inversion yields a model that reproduces the experimental data, identifies the main dynamic motifs, and agrees with independent experimental observations. Notably, the method explicitly accounts for continuity constraints and is robust even for noisy data.
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Affiliation(s)
- Kyle Acheson
- EaStCHEM, School of Chemistry and Centre for Science at Extreme Conditions, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, United Kingdom
| | - Adam Kirrander
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
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6
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Sekikawa T, Saito N, Kurimoto Y, Ishii N, Mizuno T, Kanai T, Itatani J, Saita K, Taketsugu T. Real-time observation of the Woodward-Hoffmann rule for 1,3-cyclohexadiene by femtosecond soft X-ray transient absorption. Phys Chem Chem Phys 2023; 25:8497-8506. [PMID: 36883468 DOI: 10.1039/d2cp05268g] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
The stereochemistry of pericyclic reactions is explained by orbital symmetry conservation, referred to as the Woodward-Hoffmann (WH) rule. Although this rule has been verified using the structures of reactants and products, the temporal evolution of the orbital symmetry during the reaction has not been clarified. Herein, we used femtosecond soft X-ray transient absorption spectroscopy to elucidate the thermal pericyclic reaction of 1,3-cyclohexadiene (CHD) molecules, i.e., their isomerization to 1,3,5-hexatriene. In the present experimental scheme, the ring-opening reaction is driven by the thermal vibrational energy induced by photoexcitation to the Rydberg states at 6.2 eV and subsequent femtosecond relaxation to the ground state of CHD molecules. The direction of the ring opening, which can be conrotatory or disrotatory, was the primary focus, and the WH rule predicts the disrotatory pathway in the thermal process. We observed the shifts in K-edge absorption of the carbon atom from the 1s orbital to vacant molecular orbitals around 285 eV at a delay between 340 and 600 fs. Furthermore, a theoretical investigation predicts that the shifts depend on the molecular structures along the reaction pathways and the observed shifts in induced absorption are attributed to the structural change in the disrotatory pathway. This confirms that the orbital symmetry is dynamically conserved in the ring-opening reaction of CHD molecules as predicted using the WH rule.
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Affiliation(s)
- Taro Sekikawa
- Department of Applied Physics, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan.
| | - Nariyuki Saito
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - Yutaro Kurimoto
- Department of Applied Physics, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan.
| | - Nobuhisa Ishii
- Kansai Photon Science Institute, National Institutes for Quantum and Radiological Science and Technology, Kizugawa 619-0215, Japan
| | - Tomoya Mizuno
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - Teruto Kanai
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - Jiro Itatani
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - Kenichiro Saita
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Tetsuya Taketsugu
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
- Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo 001-0021, Japan
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7
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Zhang L, Shu Y, Bhaumik S, Chen X, Sun S, Huang Y, Truhlar DG. Nonadiabatic Dynamics of 1,3-Cyclohexadiene by Curvature-Driven Coherent Switching with Decay of Mixing. J Chem Theory Comput 2022; 18:7073-7081. [PMID: 36350795 DOI: 10.1021/acs.jctc.2c00801] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The photoinduced ring-opening reaction of 1,3-cyclohexadiene to produce 1,3,5-hexatriene is a classic electrocyclic reaction and is also a prototype for many reactions of biological and synthetic importance. Here, we simulate the ultrafast nonadiabatic dynamics of the reaction in the manifold of the three lowest valence electronic states by using extended multistate complete-active-space second-order perturbation theory (XMS-CASPT2) combined with the curvature-driven coherent switching with decay of mixing (κCSDM) dynamical method. We obtain an excited-state lifetime of 79 fs, and a product quantum yield of 40% from the 500 trajectories initiated in the S1 excited state. The obtained lifetime and quantum yield values are very close to previously reported experimental and computed values, showing the capability of performing a reasonable nonadiabatic ring-opening dynamics with the κCSDM method that does not require nonadiabatic coupling vectors, time derivatives, or diabatization. In addition, we study the ring-opening reaction by initiating the trajectories in the dark state S2. We also optimize the S0/S1 and S1/S2 minimum-energy conical intersections (MECIs) by XMS-CASPT2; for S1/S2, we optimized both an inner and an outer local-minimum-energy conical intersections (LMECIs). We provide the potential energy profile along the ring-opening coordinate by joining selected critical points via linear synchronous transit paths. We find the inner S1/S2 LMECI to be more crucial than the outer one.
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Affiliation(s)
- Linyao Zhang
- School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, P. R. China.,School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, P. R. China
| | - Yinan Shu
- Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
| | - Suman Bhaumik
- Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
| | - Xiye Chen
- School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, P. R. China.,School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, P. R. China
| | - Shaozeng Sun
- School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, P. R. China
| | - Yudong Huang
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, P. R. China
| | - Donald G Truhlar
- Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
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8
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Travnikova O, Piteša T, Ponzi A, Sapunar M, Squibb RJ, Richter R, Finetti P, Di Fraia M, De Fanis A, Mahne N, Manfredda M, Zhaunerchyk V, Marchenko T, Guillemin R, Journel L, Prince KC, Callegari C, Simon M, Feifel R, Decleva P, Došlić N, Piancastelli MN. Photochemical Ring-Opening Reaction of 1,3-Cyclohexadiene: Identifying the True Reactive State. J Am Chem Soc 2022; 144:21878-21886. [PMID: 36444673 PMCID: PMC9732879 DOI: 10.1021/jacs.2c06296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The photochemically induced ring-opening isomerization reaction of 1,3-cyclohexadiene to 1,3,5-hexatriene is a textbook example of a pericyclic reaction and has been amply investigated with advanced spectroscopic techniques. The main open question has been the identification of the single reactive state which drives the process. The generally accepted description of the isomerization pathway starts with a valence excitation to the lowest lying bright state, followed by a passage through a conical intersection to the lowest lying doubly excited state, and finally a branching between either the return to the ground state of the cyclic molecule or the actual ring-opening reaction leading to the open-chain isomer. Here, in a joint experimental and computational effort, we demonstrate that the evolution of the excitation-deexcitation process is much more complex than that usually described. In particular, we show that an initially high-lying electronic state smoothly decreasing in energy along the reaction path plays a key role in the ring-opening reaction.
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Affiliation(s)
- Oksana Travnikova
- Sorbonne
Université, CNRS, Laboratoire de Chimie Physique-Matière
et Rayonnement, LCPMR, ParisF-75005, France
| | | | - Aurora Ponzi
- Institut
Rud̵er Bošković, ZagrebHR-10000, Croatia
| | | | | | | | | | | | | | - Nicola Mahne
- IOM-CNR, S.S. 14 km 163.5 in Area Science
Park, Trieste34149, Italy
| | | | - Vitali Zhaunerchyk
- Department
of Physics, University of Gothenburg, GothenburgSE-412 96, Sweden
| | - Tatiana Marchenko
- Sorbonne
Université, CNRS, Laboratoire de Chimie Physique-Matière
et Rayonnement, LCPMR, ParisF-75005, France
| | - Renaud Guillemin
- Sorbonne
Université, CNRS, Laboratoire de Chimie Physique-Matière
et Rayonnement, LCPMR, ParisF-75005, France
| | - Loic Journel
- Sorbonne
Université, CNRS, Laboratoire de Chimie Physique-Matière
et Rayonnement, LCPMR, ParisF-75005, France
| | | | | | - Marc Simon
- Sorbonne
Université, CNRS, Laboratoire de Chimie Physique-Matière
et Rayonnement, LCPMR, ParisF-75005, France
| | - Raimund Feifel
- Department
of Physics, University of Gothenburg, GothenburgSE-412 96, Sweden
| | - Piero Decleva
- Dipartimento
di Scienze Chimiche e Farmaceutiche, Universitá
di Trieste, TriesteI-34127, Italy
| | - Nad̵a Došlić
- Institut
Rud̵er Bošković, ZagrebHR-10000, Croatia,
| | - Maria Novella Piancastelli
- Sorbonne
Université, CNRS, Laboratoire de Chimie Physique-Matière
et Rayonnement, LCPMR, ParisF-75005, France,Department
of Physics and Astronomy, Uppsala University, UppsalaSE-751 20, Sweden,
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9
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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: 1] [Impact Index Per Article: 0.5] [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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10
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Seeman JI. Sleeping Beauties in Chemistry. Oosterhoff, Havinga and Schlatmann: Four Years Before "The Woodward-Hoffmann Rules" †. CHEM REC 2022; 22:e202100245. [PMID: 35234330 DOI: 10.1002/tcr.202100245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 11/13/2021] [Accepted: 01/11/2022] [Indexed: 11/11/2022]
Abstract
Several forerunners to the Woodward-Hoffmann rules appear in the chemical literature in the early 1960s. While these precedents refer to orbital symmetry and explain either electrocyclic reactions (Luitzen Oosterhoff, cited by Egbert Havinga and Jos Schlatmann in Tetrahedron in 1961) or some cycloaddition reactions (Kenichi Fukui, in a book chapter published in 1964), they did not attract any attention and did not serve to initiate any research prior to the publication of the five Woodward and Hoffmann communications in 1965. Even Woodward and Hoffmann were unaware of these precedents (though Hoffmann knew of Fukui's frontier orbital theory) until after they had completed the relevant portions of their work. The Oosterhoff-Havinga-Schlatmann story will be told in this paper; the Fukui story will be told in the next paper in this series on the history of the development of the Woodward-Hoffmann rules. Explanations for these precedents not being productive in solving the no-mechanism problem are discussed.
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Affiliation(s)
- Jeffrey I Seeman
- Department of Chemistry, University of Richmond, Richmond, VA 23173, USA
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11
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Guerra C, Ayarde-Henríquez L, Duque-Noreña M, Chamorro E. On Electron Pair Rearrangements in Photochemical Reactions: 1,3-Cyclohexadiene Ring Opening. J Phys Chem A 2021; 126:395-405. [PMID: 34923827 DOI: 10.1021/acs.jpca.1c07800] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
1,3-Cyclohexadiene ring opening has been studied within the bonding evolution theory (BET) framework. We have focused on describing for the first time the electron pair rearrangements leading to the cis-1,3,5-hexatriene (HT) product from CHD. The nature of bonding in this process begins with the weakening of the double bonds in the Franck-Condon region. Along the 11B surface, the C-C sigma bond weakens. Meanwhile, its density redistributes toward the whole CHD ring, mainly over double bonds. Breaking of this bond occurs on the 21A surface due to the symmetrical splitting of pair density from this region. This density redistributes toward the reaction center once the pericyclic minimum is reached. The formation of the double bonds that characterize HT occurs gradually in the ground state. However, near the 21A/11A intersection, these bonds are partially established.
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Affiliation(s)
- Cristian Guerra
- Facultad de Ciencias Exactas. Departamento de Ciencias Químicas, Universidad Andrés Bello, Avenida República 275, 8370146 Santiago de Chile, Chile
| | - Leandro Ayarde-Henríquez
- Facultad de Ciencias Exactas. Departamento de Ciencias Químicas, Universidad Andrés Bello, Avenida República 275, 8370146 Santiago de Chile, Chile
| | - Mario Duque-Noreña
- Facultad de Ciencias Exactas. Departamento de Ciencias Químicas, Universidad Andrés Bello, Avenida República 275, 8370146 Santiago de Chile, Chile
| | - Eduardo Chamorro
- Facultad de Ciencias Exactas. Departamento de Ciencias Químicas, Universidad Andrés Bello, Avenida República 275, 8370146 Santiago de Chile, Chile
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12
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Saalbach L, Kotsina N, Crane SW, Paterson MJ, Townsend D. Ultraviolet Excitation Dynamics of Nitrobenzenes. J Phys Chem A 2021; 125:7174-7184. [PMID: 34379417 DOI: 10.1021/acs.jpca.1c04893] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Time-resolved photoelectron imaging was used to investigate nonadiabatic processes operating in the excited electronic states of nitrobenzene and three methyl-substituted derivatives: 3,5-, 2,6-, and 2,4-dimethylnitrobenzene. The primary goal was evaluating the dynamical impact of the torsional angle between the NO2 group and the benzene ring plane-something previously implicated in mediating the propensity for branching into different photodissociation pathways (NO vs NO2 elimination). Targeted, photoinitiated release of NO radicals is of interest for clinical medicine applications, and there is a need to establish basic structure-dynamics-function principles in systematically varied model systems following photoexcitation. Within our 200 ps experimental detection window, we observed no significant differences in the excited-state lifetimes exhibited by all species under study using a 267 nm pump and ionization with an intense 400 nm probe. In agreement with previous theoretical predictions, this suggests that the initial energy redistribution dynamics within the singlet and triplet manifolds are driven by motions localized predominantly on the NO2 group. Our findings also imply that both NO and NO2 elimination occur from a vibrationally hot ground state on extended (nanosecond) timescales, and any variations in NO vs NO2 branching upon site-selective methylation are due to steric effects influencing isomerization prior to dissociation.
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Affiliation(s)
- Lisa Saalbach
- Institute of Photonics & Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Nikoleta Kotsina
- Institute of Photonics & Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Stuart W Crane
- Institute of Photonics & Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Martin J Paterson
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Dave Townsend
- Institute of Photonics & Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K.,Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
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13
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Karashima S, Humeniuk A, Uenishi R, Horio T, Kanno M, Ohta T, Nishitani J, Mitrić R, Suzuki T. Ultrafast Ring-Opening Reaction of 1,3-Cyclohexadiene: Identification of Nonadiabatic Pathway via Doubly Excited State. J Am Chem Soc 2021; 143:8034-8045. [DOI: 10.1021/jacs.1c01896] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Shutaro Karashima
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Alexander Humeniuk
- Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Emil-Fischer-Straße 42, Würzburg 97074, Germany
| | - Ryuta Uenishi
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Takuya Horio
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Manabu Kanno
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
| | - Tetsuro Ohta
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Junichi Nishitani
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Roland Mitrić
- Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Emil-Fischer-Straße 42, Würzburg 97074, Germany
| | - Toshinori Suzuki
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
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14
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Sofferman DL, Konar A, Spears KG, Sension RJ. Ultrafast excited state dynamics of provitamin D 3 and analogs in solution and in lipid bilayers. J Chem Phys 2021; 154:094309. [PMID: 33685160 DOI: 10.1063/5.0041375] [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
The photochemical ring-opening reaction of 7-dehydrocholesterol (DHC, provitamin D3) is responsible for the light-initiated formation of vitamin D3 in mammalian skin membranes. Visible transient absorption spectroscopy was used to explore the excited state dynamics of DHC and two analogs: ergosterol (provitamin D2) and DHC acetate free in solution and confined to lipid bilayers chosen to model the biological cell membrane. In solution, the excited state dynamics of the three compounds are nearly identical. However, when confined to lipid bilayers, the heterogeneity of the lipid membrane and packing forces imposed on the molecule by the lipid alter the excited state dynamics of these compounds. When confined to lipid bilayers in liposomes formed using DPPC, two solvation environments are identified. The excited state dynamics for DHC and analogs in fluid-like regions of the liposome membrane undergo internal conversion and ring-opening on 1 ps-2 ps time scales, similar to those observed in isotropic solution. In contrast, the excited state lifetime of a subpopulation in regions of lower fluidity is 7 ps-12 ps. The long decay component is unique to these liposomes and results from the structural properties of the lipid bilayer. Additional measurements in liposomes prepared with lipids having slightly longer or shorter alkane tails support this conclusion. In the lipid environments studied, the longest lifetimes are observed for DHC. The unsaturated sterol tail of ergosterol and the acetate group of DHC acetate disrupt the packing around the molecule and permit faster internal conversion and relaxation back to the ground state.
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Affiliation(s)
- Danielle L Sofferman
- Program in Applied Physics, University of Michigan, 450 Church Street, Ann Arbor, Michigan 48109-1040, USA
| | - Arkaprabha Konar
- Department of Physics, University of Michigan, 450 Church Street, Ann Arbor, Michigan 48109-1040, USA
| | - Kenneth G Spears
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, USA
| | - Roseanne J Sension
- Department of Physics, University of Michigan, 450 Church Street, Ann Arbor, Michigan 48109-1040, USA
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15
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Liu Y, Chakraborty P, Matsika S, Weinacht T. Excited state dynamics of cis,cis-1,3-cyclooctadiene: UV pump VUV probe time-resolved photoelectron spectroscopy. J Chem Phys 2020; 153:074301. [PMID: 32828099 DOI: 10.1063/5.0006920] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present UV pump, vacuum ultraviolet probe time-resolved photoelectron spectroscopy measurements of the excited state dynamics of cis,cis-1,3-cyclooctadiene. A 4.75 eV deep UV pump pulse launches a vibrational wave packet on the first electronically excited state, and the ensuing dynamics are probed via ionization using a 7.92 eV probe pulse. The experimental results indicate that the wave packet undergoes rapid internal conversion to the ground state in under 100 fs. Comparing the measurements with electronic structure and trajectory surface hopping calculations, we are able to interpret the features in the measured photoelectron spectra in terms of ionization to several states of the molecular cation.
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Affiliation(s)
- Yusong Liu
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA
| | - Pratip Chakraborty
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - Spiridoula Matsika
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - Thomas Weinacht
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA
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16
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Filatov M, Lee S, Nakata H, Choi CH. Structural or population dynamics: what is revealed by the time-resolved photoelectron spectroscopy of 1,3-cyclohexadiene? A study with an ensemble density functional theory method. Phys Chem Chem Phys 2020; 22:17567-17573. [PMID: 32716454 DOI: 10.1039/d0cp02963g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Time-resolved photoelectron spectra during the photochemical ring-opening reaction of 1,3-cyclohexadiene (CHD) are modeled by an ensemble density functional theory (eDFT) method. The computational methodology employed in this work is capable of correctly describing the multi-reference effects arising in the ground and excited electronic states of molecules, which is important for the correct description of the ring-opening reaction of CHD. The geometries of molecular species along the non-adiabatic molecular dynamics (NAMD) trajectories reported in a previous study of the CHD photochemical ring-opening were used in this work to calculate the ionization energies and the respective Dyson orbitals for all possible ionization channels. The obtained theoretical time-resolved spectra display decay characteristics in a reasonable agreement with the experimental observations; i.e., the decay (and rise) of the most mechanistically significant signals occurs on the timescale of 100-150 fs. This is very different from the excited state population decay characteristics (τS1 = 234 ± 8 fs) obtained in the previous NAMD study. The difference between the population decay and the decay of the photoelectron signal intensity is traced back to the geometric transformation that the molecule undergoes during the photoreaction. This demonstrates the importance of including the geometric information in interpretation of the experimental observations.
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Affiliation(s)
- Michael Filatov
- Department of Chemistry, Kyungpook National University, Daegu 702-701, South Korea.
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17
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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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18
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Observation of the molecular response to light upon photoexcitation. Nat Commun 2020; 11:2157. [PMID: 32358535 PMCID: PMC7195484 DOI: 10.1038/s41467-020-15680-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 03/23/2020] [Indexed: 12/02/2022] Open
Abstract
When a molecule interacts with light, its electrons can absorb energy from the electromagnetic field by rapidly rearranging their positions. This constitutes the first step of photochemical and photophysical processes that include primary events in human vision and photosynthesis. Here, we report the direct measurement of the initial redistribution of electron density when the molecule 1,3-cyclohexadiene (CHD) is optically excited. Our experiments exploit the intense, ultrashort hard x-ray pulses of the Linac Coherent Light Source (LCLS) to map the change in electron density using ultrafast x-ray scattering. The nature of the excited electronic state is identified with excellent spatial resolution and in good agreement with theoretical predictions. The excited state electron density distributions are thus amenable to direct experimental observation. Photoabsorption is a fundamental process that leads to changes in the electron density in matter. Here, the authors show a direct measurement of the distribution of electron density when a cyclohexadine molecule is excited by pulsed UV radiation and probed by a time delayed X-ray pulse generated at LCLS.
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19
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Abstract
MC-PDFT can give the most accurate excitation energies for both valence and Rydberg states of 1,4-cyclohexadiene and 1,3-cyclohexadiene when the active space includes Rydberg orbitals.
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Affiliation(s)
- Jiaxin Ning
- Department of Chemistry, Chemical Theory Center, and Minnesota Supercomputing Institute
- University of Minnesota
- Minneapolis
- USA
| | - Donald G. Truhlar
- Department of Chemistry, Chemical Theory Center, and Minnesota Supercomputing Institute
- University of Minnesota
- Minneapolis
- USA
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20
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Simmermacher M, Moreno Carrascosa A, E. Henriksen N, B. Møller K, Kirrander A. Theory of ultrafast x-ray scattering by molecules in the gas phase. J Chem Phys 2019; 151:174302. [DOI: 10.1063/1.5110040] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Mats Simmermacher
- EaStCHEM, School of Chemistry, University of Edinburgh, EH9 3FJ Edinburgh, United Kingdom
| | | | - Niels E. Henriksen
- Department of Chemistry, Technical University of Denmark, 2800 Lyngby, Denmark
| | - Klaus B. Møller
- Department of Chemistry, Technical University of Denmark, 2800 Lyngby, Denmark
| | - Adam Kirrander
- EaStCHEM, School of Chemistry, University of Edinburgh, EH9 3FJ Edinburgh, United Kingdom
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21
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Polyak I, Hutton L, Crespo-Otero R, Barbatti M, Knowles PJ. Ultrafast Photoinduced Dynamics of 1,3-Cyclohexadiene Using XMS-CASPT2 Surface Hopping. J Chem Theory Comput 2019; 15:3929-3940. [DOI: 10.1021/acs.jctc.9b00396] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Iakov Polyak
- School of Chemistry, Cardiff University, Cardiff CF10 3AT, United Kingdom
| | - Lewis Hutton
- School of Chemistry, Cardiff University, Cardiff CF10 3AT, United Kingdom
| | - Rachel Crespo-Otero
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom
| | | | - Peter J. Knowles
- School of Chemistry, Cardiff University, Cardiff CF10 3AT, United Kingdom
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22
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The photochemical ring-opening of 1,3-cyclohexadiene imaged by ultrafast electron diffraction. Nat Chem 2019; 11:504-509. [DOI: 10.1038/s41557-019-0252-7] [Citation(s) in RCA: 111] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 03/07/2019] [Indexed: 11/09/2022]
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23
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Northey T, Kirrander A. Ab Initio Fragment Method for Calculating Molecular X-ray Diffraction. J Phys Chem A 2019; 123:3395-3406. [PMID: 30892904 DOI: 10.1021/acs.jpca.9b00621] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A fragment-based approach for the prediction of elastic X-ray scattering is presented. The total diffraction pattern is assembled from anisotropic form factors calculated for individual molecular fragments, optionally including corrections for pairwise interactions between fragments. The approach is evaluated against full ab initio scattering calculations in the peptide diphenylalanine, and the optimal selection of fragments is examined in the ethanol molecule. The approach is found to improve significantly on the independent atom model while remaining conceptually simple and computationally efficient. It is expected to be particularly useful for macromolecules with repeated subunits, such as peptides, proteins, DNA, or RNA and other polymers, where it is straightforward to define appropriate fragments.
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Affiliation(s)
- Thomas Northey
- EaStCHEM, School of Chemistry , University of Edinburgh , David Brewster Road , Edinburgh EH9 3FJ , United Kingdom
| | - Adam Kirrander
- EaStCHEM, School of Chemistry , University of Edinburgh , David Brewster Road , Edinburgh EH9 3FJ , United Kingdom
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24
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Bellshaw D, Minns RS, Kirrander A. Correspondence between electronic structure calculations and simulations: nonadiabatic dynamics in CS2. Phys Chem Chem Phys 2019; 21:14226-14237. [DOI: 10.1039/c8cp05693e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The choice of ab initio electronic structure method is an important factor in determining the fidelity of nonadiabatic dynamics simulations.
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Affiliation(s)
- Darren Bellshaw
- EaStCHEM, School of Chemistry, University of Edinburgh
- EH9 3FJ Edinburgh
- UK
| | - Russell S. Minns
- Chemistry, University of Southampton, Highfield
- Southampton SO17 1BJ
- UK
| | - Adam Kirrander
- EaStCHEM, School of Chemistry, University of Edinburgh
- EH9 3FJ Edinburgh
- UK
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25
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Wolf TJA, Yang J, Sanchez DM, Nunes JPF, Parrish RM, Shen X, Centurion M, Coffee R, Gyan JP, Gühr M, Kareem H, Kirrander A, Li R, Ruddock J, Veccione T, Weathersby SP, Weber PM, Wilkin K, Yong HW, Zheng Q, Martinez TJ, Wang X, Minitti MP. Imaging the ring opening reaction of 1,3-cyclohexadiene with MeV ultrafast electron diffraction. EPJ WEB OF CONFERENCES 2019. [DOI: 10.1051/epjconf/201920507006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We resolve the structural dynamics of the ultrafast photoinduced ring opening reaction of 1,3-cyclohexadiene in space and time employing megaelectronvolt gas phase ultrafast electron diffraction. We, furthermore, observe coherent large amplitude motions of the photoproduct.
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26
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Ashfold MNR, Ingle RA, Karsili TNV, Zhang J. Photoinduced C–H bond fission in prototypical organic molecules and radicals. Phys Chem Chem Phys 2019; 21:13880-13901. [DOI: 10.1039/c8cp07454b] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We survey and assess current knowledge regarding the primary photochemistry of hydrocarbon molecules and radicals.
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Affiliation(s)
| | | | | | - Jingsong Zhang
- Department of Chemistry
- University of California at Riverside
- Riverside
- USA
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27
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Bhattacherjee A, Leone SR. Ultrafast X-ray Transient Absorption Spectroscopy of Gas-Phase Photochemical Reactions: A New Universal Probe of Photoinduced Molecular Dynamics. Acc Chem Res 2018; 51:3203-3211. [PMID: 30462481 DOI: 10.1021/acs.accounts.8b00462] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Time-resolved spectroscopic investigations of light-induced chemical reactions with universal detection capitalize recently on single-photon molecular probing using laser pulses in the extreme ultraviolet or X-ray regimes. Direct and simultaneous mappings of the time-evolving populations of ground-state reactants, Franck-Condon (FC) and transition state regions, excited-state intermediates and conical intersections (CI), and photoproducts in photochemical reactions utilize probe pulses that are broadband and energy-tunable. The limits on temporal resolution are set by the transit- or dwell-time of the photoexcited molecules at specific locations on the potential energy surface, typically ranging from a few femtoseconds to several hundred picoseconds. Femtosecond high-harmonic generation (HHG) meets the stringent demands for a universal spectroscopic probe of large regions of the intramolecular phase-space in unimolecular photochemical reactions. Extreme-ultraviolet and soft X-ray pulses generated in this manner with few-femtosecond or sub-femtosecond durations have enormous bandwidths, allowing the probing of many elements simultaneously through excitation or ionization of core-electrons, creating molecular movies that shed light on entire photochemical pathways. At free electron lasers (FELs), powerful investigations are also possible, recognizing their higher flux and tunability but more limited bandwidths. Femtosecond time-resolved X-ray transient absorption spectroscopy, in particular, is a valuable universal probe of reaction pathways that maps changes via the fingerprint core-to-valence resonances. The particular power of this method over valence-ionization probes lies in its unmatched element and chemical-site specificities. The elements carbon, nitrogen, and oxygen constitute the fundamental building blocks of life; photochemical reactions involving these elements are ubiquitous, diverse, and manifold. However, table-top HHG sources in the "water-window" region (280-550 eV), which encompasses the 1s-absorption edges of carbon (284 eV), nitrogen (410 eV), and oxygen (543 eV), are far from abundant or trivial. Recent breakthroughs in the laboratory have embraced this region by using long driving-wavelength optical parametric amplifiers coupled with differentially pumped high-pressure gas source cells. This has opened avenues to study a host of photochemical reactions in organic molecules using femtosecond time-resolved transient absorption at the carbon K-edge. In this Account, we summarize recent efforts to deploy a table-top carbon K-edge source to obtain crucial chemical insights into ultrafast, ultraviolet-induced chemical reactions involving ring-opening, nonadiabatic excited-state relaxation, bond dissociation and radical formation. The X-ray probe provides a direct spectroscopic viewport into the electronic characters and configurations of the valence electronic states through spectroscopic core-level transitions into the frontier molecular orbitals of the photoexcited molecules, laying fertile ground for the real-time mapping of the evolving valence electronic structure. The profound detail and mechanistic insights emerging from the pioneering experiments at the carbon K-edge are outlined here. Comparisons of the experimental methodology with other techniques employed to study similar reactions are drawn, where applicable and relevant. We show that femtosecond time-resolved X-ray transient absorption spectroscopy blazes a new trail in the study of nonadiabatic molecular dynamics. Despite table-top implementations being largely in their infancy, future chemical applications of the technique will set the stage for widely applicable, universal probes of photoinduced molecular dynamics with unprecedented temporal resolution.
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Affiliation(s)
- Aditi Bhattacherjee
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Stephen R. Leone
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department of Physics, University of California, Berkeley, California 94720, United States
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28
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Kaneshima K, Ninota Y, Sekikawa T. Time-resolved high-harmonic spectroscopy of ultrafast photoisomerization dynamics. OPTICS EXPRESS 2018; 26:31039-31054. [PMID: 30469991 DOI: 10.1364/oe.26.031039] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 10/01/2018] [Indexed: 06/09/2023]
Abstract
We report the first time-resolved high-harmonic spectroscopy (TR-HHS) study of a chemical bond rearrangement. We investigate the transient change of the high-harmonic signal from 1,3-cyclohexadiene (CHD), which undergoes ring-opening and isomerizes to 1,3,5-hexatriene (HT) upon photoexcitation. We associated the harmonic yield variation with the changes in the molecule's electronic state and vibrational frequencies, which are caused by isomerization. This showed us that the electronic excited state of CHD created through two-photon absorption of 3.1 eV photons relaxes almost completely within 100 fs to the electronic ground state of CHD with vibrational excitation. Subsequently, the molecule isomerizes to HT (i.e., ring-opening occurs, around 400 fs after the excitation). The present results demonstrate that TR-HHS, which can track both electronic and nuclear dynamics, is a powerful tool for studying ultrafast photochemical reactions.
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29
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Schalk O, Geng T, Hansson T, Thomas RD. The ring-opening channel and the influence of Rydberg states on the excited state dynamics of furan and its derivatives. J Chem Phys 2018; 149:084303. [PMID: 30193494 DOI: 10.1063/1.5024655] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
One important relaxation pathway for photo-excited five-membered heterocyclic organic molecules is ring-opening via a dissociative πσ* state. In this study, we investigate the influence of this pathway in furan and several hydrogenated and methylated derivatives by combining time-resolved photoelectron spectroscopy with time-dependent density functional theory and coupled cluster calculations. We find strong experimental evidence that the ring-opening channel is the major relaxation channel in furan, 2,3-dihydrofuran, and 2-methylfuran (2-MF). In 2,5-dimethylfuran (25-DMF), however, we observe that the molecules relax either via a π3s Rydberg state or through a direct return to the ground state by undergoing ring-puckering motions. From the supporting calculations, for 2-MF and 25-DMF, we predict that there is strong mixing between the πσ* state and the π3s Rydberg state along the ring opening pathway. However, in 25-DMF, no crossing between the πσ*/π3s state and the initially excited ππ* state can be found along the ring opening coordinate, effectively blocking this channel.
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Affiliation(s)
- O Schalk
- Department of Physics, AlbaNova University Center, Stockholm University, 106 91 Stockholm, Sweden
| | - T Geng
- Department of Physics, AlbaNova University Center, Stockholm University, 106 91 Stockholm, Sweden
| | - T Hansson
- Department of Physics, AlbaNova University Center, Stockholm University, 106 91 Stockholm, Sweden
| | - R D Thomas
- Department of Physics, AlbaNova University Center, Stockholm University, 106 91 Stockholm, Sweden
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30
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Iikubo R, Sekikawa T, Harabuchi Y, Taketsugu T. Structural dynamics of photochemical reactions probed by time-resolved photoelectron spectroscopy using high harmonic pulses. Faraday Discuss 2018; 194:147-160. [PMID: 27711881 DOI: 10.1039/c6fd00063k] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Femtosecond ring-opening dynamics of 1,3-cyclohexadiene (CHD) in gas phase upon two-photon excitation at 400 nm (=3.1 eV) was investigated by time-resolved photoelectron spectroscopy using 42 nm (=29.5 eV) high harmonic photons probing the dynamics of the lower-lying occupied molecular orbitals (MOs), which are the fingerprints of the molecular structure. After 500 fs, the photoelectron intensity of the MO constituting the C[double bond, length as m-dash]C sigma bond (σC[double bond, length as m-dash]C) of CHD was enhanced, while that of the MO forming the C-C sigma bond (σCC) of CHD was decreased. The changes in the photoelectron spectra suggest that the ring of CHD opens to form a 1,3,5-hexatriene (HT) after 500 fs. The dynamics of the σC[double bond, length as m-dash]C and σCC bands between 200 and 500 fs reflects the ring deformation to a conical intersection between the 21A and 11A potential energy surfaces prior to the ring-opening reaction.
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Affiliation(s)
- Ryo Iikubo
- Department of Applied Physics, Faculty of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo 060-8628, Japan.
| | - Taro Sekikawa
- Department of Applied Physics, Faculty of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo 060-8628, Japan.
| | - Yu Harabuchi
- Department of Chemistry, Faculty of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo 060-0810, Japan
| | - Tetsuya Taketsugu
- Department of Chemistry, Faculty of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo 060-0810, Japan
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31
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Stankus B, Zotev N, Rogers DM, Gao Y, Odate A, Kirrander A, Weber PM. Ultrafast photodissociation dynamics of 1,4-diiodobenzene. J Chem Phys 2018; 148:194306. [DOI: 10.1063/1.5031787] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Affiliation(s)
- Brian Stankus
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Nikola Zotev
- EaStCHEM, School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, United Kingdom
| | - David M. Rogers
- EaStCHEM, School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, United Kingdom
| | - Yan Gao
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Asami Odate
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Adam Kirrander
- EaStCHEM, School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, United Kingdom
| | - Peter M. Weber
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
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32
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Tudorovskaya M, Minns RS, Kirrander A. Effects of probe energy and competing pathways on time-resolved photoelectron spectroscopy: the ring-opening of 1,3-cyclohexadiene. Phys Chem Chem Phys 2018; 20:17714-17726. [DOI: 10.1039/c8cp02397b] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Photoelectron spectra for the ring-opening dynamics of 1,3-cyclohexadiene are studied using a model based on quantum molecular dynamics and the Dyson orbital approach.
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Affiliation(s)
| | | | - Adam Kirrander
- EaStCHEM
- School of Chemistry
- University of Edinburgh
- Edinburgh
- UK
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33
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Bhattacherjee A, Pemmaraju CD, Schnorr K, Attar AR, Leone SR. Ultrafast Intersystem Crossing in Acetylacetone via Femtosecond X-ray Transient Absorption at the Carbon K-Edge. J Am Chem Soc 2017; 139:16576-16583. [DOI: 10.1021/jacs.7b07532] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Aditi Bhattacherjee
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Chaitanya Das Pemmaraju
- Theory
Institute for Materials and Energy Spectroscopies, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Kirsten Schnorr
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Andrew R. Attar
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Stephen R. Leone
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department
of Physics, University of California, Berkeley, California 94720, United States
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34
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35
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Nishitani J, West CW, Higashimura C, Suzuki T. Time-resolved photoelectron spectroscopy of polyatomic molecules using 42-nm vacuum ultraviolet laser based on high harmonics generation. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.07.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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36
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Ashfold MNR, Bain M, Hansen CS, Ingle RA, Karsili TNV, Marchetti B, Murdock D. Exploring the Dynamics of the Photoinduced Ring-Opening of Heterocyclic Molecules. J Phys Chem Lett 2017; 8:3440-3451. [PMID: 28661140 DOI: 10.1021/acs.jpclett.7b01219] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Excited states formed by electron promotion to an antibonding σ* orbital are now recognized as key to understanding the photofragmentation dynamics of a broad range of heteroatom containing small molecules: alcohols, thiols, amines, and many of their aromatic analogues. Such excited states may be populated by direct photoexcitation, or indirectly by nonadiabatic transfer of population from some other optically excited state (e.g., a ππ* state). This Perspective explores the extent to which the fast-growing literature pertaining to such (n/π)σ*-state mediated bond fissions can inform and enhance our mechanistic understanding of photoinduced ring-opening in heterocyclic molecules.
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Affiliation(s)
- Michael N R Ashfold
- School of Chemistry, University of Bristol , Bristol, United Kingdom , BS8 1TS
| | - Matthew Bain
- School of Chemistry, University of Bristol , Bristol, United Kingdom , BS8 1TS
| | | | - Rebecca A Ingle
- School of Chemistry, University of Bristol , Bristol, United Kingdom , BS8 1TS
| | - Tolga N V Karsili
- School of Chemistry, University of Bristol , Bristol, United Kingdom , BS8 1TS
| | - Barbara Marchetti
- School of Chemistry, University of Bristol , Bristol, United Kingdom , BS8 1TS
| | - Daniel Murdock
- School of Chemistry, University of Bristol , Bristol, United Kingdom , BS8 1TS
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37
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Ischenko AA, Weber PM, Miller RJD. Capturing Chemistry in Action with Electrons: Realization of Atomically Resolved Reaction Dynamics. Chem Rev 2017; 117:11066-11124. [DOI: 10.1021/acs.chemrev.6b00770] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Anatoly A. Ischenko
- Institute
of Fine Chemical Technologies, Moscow Technological University, Vernadskogo
86, 119571 Moscow, Russia
| | - Peter M. Weber
- Department
of Chemistry, Brown University, 324 Brook Street, 02912 Providence, Rhode Island, United States
| | - R. J. Dwayne Miller
- The Max Planck Institute for the Structure and Dynamics of Matter, Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany
- Departments
of Chemistry and Physics, University of Toronto, 80 St. George, M5S 3H6 Toronto, Canada
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38
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Fundamental Limits on Spatial Resolution in Ultrafast X-ray Diffraction. APPLIED SCIENCES-BASEL 2017. [DOI: 10.3390/app7060534] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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39
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Ashfold MN, Murdock D, Oliver TA. Molecular Photofragmentation Dynamics in the Gas and Condensed Phases. Annu Rev Phys Chem 2017; 68:63-82. [DOI: 10.1146/annurev-physchem-052516-050756] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Exciting a molecule with an ultraviolet photon often leads to bond fission, but the final outcome of the bond cleavage is typically both molecule and phase dependent. The photodissociation of an isolated gas-phase molecule can be viewed as a closed system: Energy and momentum are conserved, and the fragmentation is irreversible. The same is not true in a solution-phase photodissociation process. Solvent interactions may dissipate some of the photoexcitation energy prior to bond fission and will dissipate any excess energy partitioned into the dissociation products. Products that have no analog in the corresponding gas-phase study may arise by, for example, geminate recombination. Here, we illustrate the extent to which dynamical insights from gas-phase studies can inform our understanding of the corresponding solution-phase photochemistry and how, in the specific case of photoinduced ring-opening reactions, solution-phase studies can in some cases reveal dynamical insights more clearly than the corresponding gas-phase study.
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Affiliation(s)
| | - Daniel Murdock
- School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
| | - Thomas A.A. Oliver
- School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
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40
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Attar AR, Bhattacherjee A, Pemmaraju CD, Schnorr K, Closser KD, Prendergast D, Leone SR. Femtosecond x-ray spectroscopy of an electrocyclic ring-opening reaction. Science 2017; 356:54-59. [PMID: 28386006 DOI: 10.1126/science.aaj2198] [Citation(s) in RCA: 181] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Revised: 01/24/2017] [Accepted: 02/22/2017] [Indexed: 01/30/2023]
Abstract
The ultrafast light-activated electrocyclic ring-opening reaction of 1,3-cyclohexadiene is a fundamental prototype of photochemical pericyclic reactions. Generally, these reactions are thought to proceed through an intermediate excited-state minimum (the so-called pericyclic minimum), which leads to isomerization via nonadiabatic relaxation to the ground state of the photoproduct. Here, we used femtosecond (fs) soft x-ray spectroscopy near the carbon K-edge (~284 electron volts) on a tabletop apparatus to directly reveal the valence electronic structure of this transient intermediate state. The core-to-valence spectroscopic signature of the pericyclic minimum observed in the experiment was characterized, in combination with time-dependent density functional theory calculations, to reveal overlap and mixing of the frontier valence orbital energy levels. We show that this transient valence electronic structure arises within 60 ± 20 fs after ultraviolet photoexcitation and decays with a time constant of 110 ± 60 fs.
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Affiliation(s)
- Andrew R Attar
- Department of Chemistry, University of California, Berkeley, CA 94720, USA.,Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Aditi Bhattacherjee
- Department of Chemistry, University of California, Berkeley, CA 94720, USA.,Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - C D Pemmaraju
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.,Theory Institute for Materials and Energy Spectroscopies, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Kirsten Schnorr
- Department of Chemistry, University of California, Berkeley, CA 94720, USA.,Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Kristina D Closser
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - David Prendergast
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Stephen R Leone
- Department of Chemistry, University of California, Berkeley, CA 94720, USA. .,Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.,Department of Physics, University of California, Berkeley, CA 94720, USA
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41
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Moreno Carrascosa A, Kirrander A. Ab initio calculation of inelastic scattering. Phys Chem Chem Phys 2017; 19:19545-19553. [DOI: 10.1039/c7cp02054f] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We calculate nonresonant inelastic electron and X-ray scattering cross sections for bound-to-bound transitions in atoms and molecules from ab initio electronic wavefunctions.
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Affiliation(s)
| | - Adam Kirrander
- EaStCHEM
- School of Chemistry
- University of Edinburgh
- EH9 3FJ Edinburgh
- UK
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42
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Moreno Carrascosa A, Northey T, Kirrander A. Imaging rotations and vibrations in polyatomic molecules with X-ray scattering. Phys Chem Chem Phys 2017; 19:7853-7863. [DOI: 10.1039/c6cp06793j] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An approach for calculating elastic X-ray scattering from polyatomic molecules in specific electronic, vibrational, and rotational states is presented, and is used to consider the characterization of specific states in polyatomic molecules using elastic X-ray scattering.
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Affiliation(s)
| | - Thomas Northey
- EaStCHEM
- School of Chemistry
- University of Edinburgh
- EH9 3FJ Edinburgh
- UK
| | - Adam Kirrander
- EaStCHEM
- School of Chemistry
- University of Edinburgh
- EH9 3FJ Edinburgh
- UK
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43
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Kirrander A, Minns RS. Highlights from Faraday Discussion 193: Ultrafast Imaging of Photochemical Dynamics, Edinburgh, 2016. Chem Commun (Camb) 2016; 52:13631-13636. [PMID: 27824365 DOI: 10.1039/c6cc90504h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
On August 31st 2016, 116 delegates from 16 countries gathered at the handsome and historic premises of the Royal Society of Edinburgh.
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Affiliation(s)
- Adam Kirrander
- EaStCHEM, School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, UK.
| | - Russell S Minns
- Chemistry, University of Southampton, Highfield, Southampton, SO17 1BJ, UK.
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44
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Northey T, Moreno Carrascosa A, Schäfer S, Kirrander A. Elastic X-ray scattering from state-selected molecules. J Chem Phys 2016; 145:154304. [PMID: 27782487 DOI: 10.1063/1.4962256] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The characterization of electronic, vibrational, and rotational states using elastic (coherent) X-ray scattering is considered. The scattering is calculated directly from complete active space self-consistent field level ab initio wavefunctions for H2 molecules in the ground-state X1Σg+ and first-excited EF1Σg+ electronic states. The calculated scattering is compared to recent experimental measurements [Y.-W. Liu et al., Phys. Rev. A 89, 014502 (2014)], and the influence of vibrational and rotational states on the observed signal is examined. The scaling of the scattering calculations with basis set is quantified, and it is found that energy convergence of the ab initio calculations is a good indicator of the quality of the scattering calculations.
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Affiliation(s)
- Thomas Northey
- EaStCHEM, School of Chemistry, University of Edinburgh, David Brewster Road, EH9 3FJ Edinburgh, United Kingdom
| | - Andrés Moreno Carrascosa
- EaStCHEM, School of Chemistry, University of Edinburgh, David Brewster Road, EH9 3FJ Edinburgh, United Kingdom
| | - Steffen Schäfer
- Aix-Marseille Université and Institut Matériaux Microélectronique Nanosciences de Provence (IM2NP), Marseille, France
| | - Adam Kirrander
- EaStCHEM, School of Chemistry, University of Edinburgh, David Brewster Road, EH9 3FJ Edinburgh, United Kingdom
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45
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Smith AD, Watts HM, Jager E, Horke DA, Springate E, Alexander O, Cacho C, Chapman RT, Minns RS. Resonant multiphoton ionisation probe of the photodissociation dynamics of ammonia. Phys Chem Chem Phys 2016; 18:28150-28156. [PMID: 27722319 DOI: 10.1039/c6cp05279g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The dissociation dynamics of the Ã-state of ammonia have been studied using a resonant multiphoton ionisation probe in a photoelectron spectroscopy experiment. The use of a resonant intermediate in the multiphoton ionisation process changes the ionisation propensity, allowing access to different ion states when compared with equivalent single photon ionisation experiments. Ionisation through the E' 1A1' Rydberg intermediate means we maintain overlap with the ion state for an extended period, allowing us to monitor the excited state population for several hundred femtoseconds. The vibrational states in the photoelectron spectrum show two distinct timescales, 200 fs and 320 fs, that we assign to the non-adiabatic and adiabatic dissociation processes respectively. The different timescales derive from differences in the wavepacket trajectories for the two dissociation pathways that resonantly excite different vibrational states in the intermediate Rydberg state. The timescales are similar to those obtained from time resolved ion kinetic energy release measurements, suggesting we can measure the different trajectories taken out to the region of conical intersection.
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Affiliation(s)
- Adam D Smith
- Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
| | - Hannah M Watts
- Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
| | - Edward Jager
- Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
| | - Daniel A Horke
- Center for Free-Electron Laser Science, DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Emma Springate
- Central Laser Facility, STFC Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX, UK
| | - Oliver Alexander
- Central Laser Facility, STFC Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX, UK
| | - Cephise Cacho
- Central Laser Facility, STFC Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX, UK
| | - Richard T Chapman
- Central Laser Facility, STFC Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX, UK
| | - Russell S Minns
- Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
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46
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Gao Y, Pemberton CC, Zhang Y, Weber PM. On the ultrafast photo-induced dynamics of α-terpinene. J Chem Phys 2016; 144:194303. [DOI: 10.1063/1.4948629] [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] Open
Affiliation(s)
- Yan Gao
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | | | - Yao Zhang
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Peter M. Weber
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
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47
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Ingle RA, Karsili TNV, Dennis GJ, Staniforth M, Stavros VG, Ashfold MNR. Extreme population inversion in the fragments formed by UV photoinduced S-H bond fission in 2-thiophenethiol. Phys Chem Chem Phys 2016; 18:11401-10. [PMID: 27056403 DOI: 10.1039/c6cp01593j] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
H atom loss following near ultraviolet photoexcitation of gas phase 2-thiophenethiol molecules has been studied experimentally, by photofragment translational spectroscopy (PTS) methods, and computationally, by ab initio electronic structure calculations. The long wavelength (277.5 ≥ λ(phot) ≥ 240 nm) PTS data are consistent with S-H bond fission after population of the first (1)πσ* state. The partner thiophenethiyl (R) radicals are formed predominantly in their first excited Ã(2)A' state, but assignment of a weak signal attributable to H + R(X˜(2)A'') products allows determination of the S-H bond strength, D0 = 27,800 ± 100 cm(-1) and the Ã-X˜ state splitting in the thiophenethiyl radical (ΔE = 3580 ± 100 cm(-1)). The deduced population inversion between the à and X˜ states of the radical reflects the non-planar ground state geometry (wherein the S-H bond is directed near orthogonal to the ring plane) which, post-photoexcitation, is unable to planarise sufficiently prior to bond fission. This dictates that the dissociating molecules follow the adiabatic fragmentation pathway to electronically excited radical products. π* ← π absorption dominates at shorter excitation wavelengths. Coupling to the same (1)πσ* potential energy surface (PES) remains the dominant dissociation route, but a minor yield of H atoms attributable to a rival fragmentation pathway is identified. These products are deduced to arise via unimolecular decay following internal conversion to the ground (S0) state PES via a conical intersection accessed by intra-ring C-S bond extension. The measured translational energy disposal shows a more striking change once λ(phot) ≤ 220 nm. Once again, however, the dominant decay pathway is deduced to be S-H bond fission following coupling to the (1)πσ* PES but, in this case, many of the evolving molecules are deduced to have sufficiently near-planar geometries to allow passage through the conical intersection at extended S-H bond lengths and dissociation to ground (X˜) state radical products. The present data provide no definitive evidence that complete ring opening can compete with fast S-H bond fission following near UV photoexcitation of 2-thiophenethiol.
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Affiliation(s)
- Rebecca A Ingle
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, UK BS8 1TS.
| | - Tolga N V Karsili
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, UK BS8 1TS.
| | - Gregg J Dennis
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, UK BS8 1TS.
| | - Michael Staniforth
- Department of Chemistry, University of Warwick, Library Road, Coventry, UK CV4 7AL
| | - Vasilios G Stavros
- Department of Chemistry, University of Warwick, Library Road, Coventry, UK CV4 7AL
| | - Michael N R Ashfold
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, UK BS8 1TS.
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48
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Schalk O, Geng T, Thompson T, Baluyot N, Thomas RD, Tapavicza E, Hansson T. Cyclohexadiene Revisited: A Time-Resolved Photoelectron Spectroscopy and ab Initio Study. J Phys Chem A 2016; 120:2320-9. [DOI: 10.1021/acs.jpca.5b10928] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Oliver Schalk
- Department
of Chemical Physics, AlbaNova University Centre, Stockholm University, Roslagstullsbacken 21, 106 91 Stockholm, Sweden
| | - Ting Geng
- Department
of Chemical Physics, AlbaNova University Centre, Stockholm University, Roslagstullsbacken 21, 106 91 Stockholm, Sweden
| | - Travis Thompson
- Department
of Chemistry and Biochemistry, California State University, Long Beach, 1250 Bellflower Boulevard, Long Beach, California 90840-9507, United States
| | - Noel Baluyot
- Department
of Chemistry and Biochemistry, California State University, Long Beach, 1250 Bellflower Boulevard, Long Beach, California 90840-9507, United States
| | - Richard D. Thomas
- Department
of Chemical Physics, AlbaNova University Centre, Stockholm University, Roslagstullsbacken 21, 106 91 Stockholm, Sweden
| | - Enrico Tapavicza
- Department
of Chemistry and Biochemistry, California State University, Long Beach, 1250 Bellflower Boulevard, Long Beach, California 90840-9507, United States
| | - Tony Hansson
- Department
of Chemical Physics, AlbaNova University Centre, Stockholm University, Roslagstullsbacken 21, 106 91 Stockholm, Sweden
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49
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Kirrander A, Saita K, Shalashilin DV. Ultrafast X-ray Scattering from Molecules. J Chem Theory Comput 2016; 12:957-67. [PMID: 26717255 DOI: 10.1021/acs.jctc.5b01042] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Adam Kirrander
- EaStCHEM,
School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, United Kingdom
| | - Kenichiro Saita
- EaStCHEM,
School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, United Kingdom
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50
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Champenois EG, Shivaram NH, Wright TW, Yang CS, Belkacem A, Cryan JP. Involvement of a low-lying Rydberg state in the ultrafast relaxation dynamics of ethylene. J Chem Phys 2016; 144:014303. [DOI: 10.1063/1.4939220] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Elio G. Champenois
- Graduate Group in Applied Science and Technology, University of California, Berkeley, California 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Niranjan H. Shivaram
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Travis W. Wright
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Department of Chemistry, University of California at Davis, Davis, California 95616, USA
| | - Chan-Shan Yang
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Ali Belkacem
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - James P. Cryan
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- PULSE Institute for Ultrafast Energy Science, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
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