1
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Huang L, Bertram L, Ma L, Goff N, Crane SW, Odate A, Northey T, Carrascosa AM, Simmermacher M, Muvva SB, Geiser JD, Lueckheide MJ, Phelps Z, Liang M, Cheng X, Forbes R, Robinson JS, Hayes MJ, Allum F, Green AE, Lopata K, Rudenko A, Wolf TJA, Centurion M, Rolles D, Minitti MP, Kirrander A, Weber PM. The Ring-Closing Reaction of Cyclopentadiene Probed with Ultrafast X-ray Scattering. J Phys Chem A 2024. [PMID: 38709555 DOI: 10.1021/acs.jpca.4c02509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2024]
Abstract
The dynamics of cyclopentadiene (CP) following optical excitation at 243 nm was investigated by time-resolved pump-probe X-ray scattering using 16.2 keV X-rays at the Linac Coherent Light Source (LCLS). We present the first ultrafast structural evidence that the reaction leads directly to the formation of bicyclo[2.1.0]pentene (BP), a strained molecule with three- and four-membered rings. The bicyclic compound decays via a thermal backreaction to the vibrationally hot CP with a time constant of 21 ± 3 ps. A minor channel leads to ring-opened structures on a subpicosecond time scale.
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Affiliation(s)
- Lisa Huang
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Lauren Bertram
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Lingyu Ma
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Nathan Goff
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Stuart W Crane
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Asami Odate
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Thomas Northey
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Andrés Moreno Carrascosa
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Mats Simmermacher
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Sri Bhavya Muvva
- Department of Physics and Astronomy, University of Nebraska - Lincoln, Lincoln, Nebraska 68588, United States
| | - Joseph D Geiser
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Matthew J Lueckheide
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Zane Phelps
- Department of Physics, Kansas State University, Manhattan, Kansas 66506, United States
| | - Mengning Liang
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Xinxin Cheng
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Ruaridh Forbes
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Joseph S Robinson
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Matthew J Hayes
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Felix Allum
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Alice E Green
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
- European XFEL, Schenefeld 22869, Germany
| | - Kenneth Lopata
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Artem Rudenko
- Department of Physics, Kansas State University, Manhattan, Kansas 66506, United States
| | - Thomas J A Wolf
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Martin Centurion
- Department of Physics and Astronomy, University of Nebraska - Lincoln, Lincoln, Nebraska 68588, United States
| | - Daniel Rolles
- Department of Physics, Kansas State University, Manhattan, Kansas 66506, United States
| | - Michael P Minitti
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Adam Kirrander
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Peter M Weber
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
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2
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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3
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Gabalski I, Sere M, Acheson K, Allum F, Boutet S, Dixit G, Forbes R, Glownia JM, Goff N, Hegazy K, Howard AJ, Liang M, Minitti MP, Minns RS, Natan A, Peard N, Rasmus WO, Sension RJ, Ware MR, Weber PM, Werby N, Wolf TJA, Kirrander A, Bucksbaum PH. Transient vibration and product formation of photoexcited CS 2 measured by time-resolved x-ray scattering. J Chem Phys 2022; 157:164305. [PMID: 36319419 PMCID: PMC9625835 DOI: 10.1063/5.0113079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 10/03/2022] [Indexed: 11/14/2022] Open
Abstract
We have observed details of the internal motion and dissociation channels in photoexcited carbon disulfide (CS2) using time-resolved x-ray scattering (TRXS). Photoexcitation of gas-phase CS2 with a 200 nm laser pulse launches oscillatory bending and stretching motion, leading to dissociation of atomic sulfur in under a picosecond. During the first 300 fs following excitation, we observe significant changes in the vibrational frequency as well as some dissociation of the C-S bond, leading to atomic sulfur in the both 1D and 3P states. Beyond 1400 fs, the dissociation is consistent with primarily 3P atomic sulfur dissociation. This channel-resolved measurement of the dissociation time is based on our analysis of the time-windowed dissociation radial velocity distribution, which is measured using the temporal Fourier transform of the TRXS data aided by a Hough transform that extracts the slopes of linear features in an image. The relative strength of the two dissociation channels reflects both their branching ratio and differences in the spread of their dissociation times. Measuring the time-resolved dissociation radial velocity distribution aids the resolution of discrepancies between models for dissociation proposed by prior photoelectron spectroscopy work.
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Affiliation(s)
- Ian Gabalski
- Author to whom correspondence should be addressed:
| | | | - Kyle Acheson
- School of Chemistry, University of Edinburgh, Edinburgh EH8 9YL, United Kingdom
| | | | - Sébastien Boutet
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Gopal Dixit
- Department of Physics, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | | | - James M. Glownia
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Nathan Goff
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | | | | | - Mengning Liang
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Michael P. Minitti
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Russell S. Minns
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Adi Natan
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Nolan Peard
- Department of Applied Physics, Stanford University, Stanford, California 94305, USA
| | - Weronika O. Rasmus
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Roseanne J. Sension
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Matthew R. Ware
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Peter M. Weber
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | | | | | - Adam Kirrander
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, OX1 3QX Oxford, United Kingdom
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4
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Yong H, Xu X, Ruddock JM, Stankus B, Carrascosa AM, Zotev N, Bellshaw D, Du W, Goff N, Chang Y, Boutet S, Carbajo S, Koglin JE, Liang M, Robinson JS, Kirrander A, Minitti MP, Weber PM. Ultrafast X-ray scattering offers a structural view of excited-state charge transfer. Proc Natl Acad Sci U S A 2021; 118:e2021714118. [PMID: 33947814 PMCID: PMC8126834 DOI: 10.1073/pnas.2021714118] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Intramolecular charge transfer and the associated changes in molecular structure in N,N'-dimethylpiperazine are tracked using femtosecond gas-phase X-ray scattering. The molecules are optically excited to the 3p state at 200 nm. Following rapid relaxation to the 3s state, distinct charge-localized and charge-delocalized species related by charge transfer are observed. The experiment determines the molecular structure of the two species, with the redistribution of electron density accounted for by a scattering correction factor. The initially dominant charge-localized state has a weakened carbon-carbon bond and reorients one methyl group compared with the ground state. Subsequent charge transfer to the charge-delocalized state elongates the carbon-carbon bond further, creating an extended 1.634 Å bond, and also reorients the second methyl group. At the same time, the bond lengths between the nitrogen and the ring-carbon atoms contract from an average of 1.505 to 1.465 Å. The experiment determines the overall charge transfer time constant for approaching the equilibrium between charge-localized and charge-delocalized species to 3.0 ps.
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Affiliation(s)
- Haiwang Yong
- Department of Chemistry, Brown University, Providence, RI 02912
| | - Xuan Xu
- Department of Chemistry, Brown University, Providence, RI 02912
| | | | - Brian Stankus
- Department of Chemistry and Biochemistry, Western Connecticut State University, Danbury, CT 06810
| | | | - Nikola Zotev
- EaStCHEM, School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
- Center for Science at Extreme Conditions, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
| | - Darren Bellshaw
- EaStCHEM, School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
- Center for Science at Extreme Conditions, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
| | - Wenpeng Du
- Department of Chemistry, Brown University, Providence, RI 02912
| | - Nathan Goff
- Department of Chemistry, Brown University, Providence, RI 02912
| | - Yu Chang
- Department of Chemistry, Brown University, Providence, RI 02912
| | - Sébastien Boutet
- Linac Coherent Light Source, Stanford Linear Accelerator Center National Accelerator Laboratory, Menlo Park, CA 94025
| | - Sergio Carbajo
- Linac Coherent Light Source, Stanford Linear Accelerator Center National Accelerator Laboratory, Menlo Park, CA 94025
| | - Jason E Koglin
- Linac Coherent Light Source, Stanford Linear Accelerator Center National Accelerator Laboratory, Menlo Park, CA 94025
| | - Mengning Liang
- Linac Coherent Light Source, Stanford Linear Accelerator Center National Accelerator Laboratory, Menlo Park, CA 94025
| | - Joseph S Robinson
- Linac Coherent Light Source, Stanford Linear Accelerator Center National Accelerator Laboratory, Menlo Park, CA 94025
| | - Adam Kirrander
- EaStCHEM, School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom;
- Center for Science at Extreme Conditions, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
| | - Michael P Minitti
- Linac Coherent Light Source, Stanford Linear Accelerator Center National Accelerator Laboratory, Menlo Park, CA 94025
| | - Peter M Weber
- Department of Chemistry, Brown University, Providence, RI 02912;
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5
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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. Struct Dyn 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] [What about the content of this article? (0)] [Affiliation(s)] [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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6
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Ruddock JM, Yong H, Stankus B, Du W, Goff N, Chang Y, Odate A, Carrascosa AM, Bellshaw D, Zotev N, Liang M, Carbajo S, Koglin J, Robinson JS, Boutet S, Kirrander A, Minitti MP, Weber PM. A deep UV trigger for ground-state ring-opening dynamics of 1,3-cyclohexadiene. Sci Adv 2019; 5:eaax6625. [PMID: 31523713 PMCID: PMC6731073 DOI: 10.1126/sciadv.aax6625] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 08/03/2019] [Indexed: 05/03/2023]
Abstract
We explore the photo-induced kinetics of 1,3-cyclohexadiene upon excitation at 200 nm to the 3p state by ultrafast time-resolved, gas-phase x-ray scattering using the Linac Coherent Light Source. Analysis of the scattering anisotropy reveals that the excitation leads to the 3px and 3py Rydberg electronic states, which relax to the ground state with a time constant of 208 ± 11 fs. In contrast to the well-studied 266 nm excitation, at 200 nm the majority of the molecules (76 ± 3%) relax to vibrationally hot cyclohexadiene in the ground electronic state. A subsequent reaction on the ground electronic state surface leads from the hot cyclohexadiene to 1,3,5-hexatriene, with rates for the forward and backward reactions of 174 ± 13 and 355 ± 45 ps, respectively. The scattering pattern of the final hexatriene product reveals a thermal distribution of rotamers about the carbon-carbon single bonds.
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Affiliation(s)
- Jennifer M. Ruddock
- Department of Chemistry, Brown University, 324 Brook St., Providence, RI 02912, USA
- SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, CA 94025, USA
| | - Haiwang Yong
- Department of Chemistry, Brown University, 324 Brook St., Providence, RI 02912, USA
| | - Brian Stankus
- Department of Chemistry, Brown University, 324 Brook St., Providence, RI 02912, USA
| | - Wenpeng Du
- Department of Chemistry, Brown University, 324 Brook St., Providence, RI 02912, USA
| | - Nathan Goff
- Department of Chemistry, Brown University, 324 Brook St., Providence, RI 02912, USA
| | - Yu Chang
- Department of Chemistry, Brown University, 324 Brook St., Providence, RI 02912, USA
| | - Asami Odate
- Department of Chemistry, Brown University, 324 Brook St., Providence, RI 02912, USA
| | - Andrés Moreno Carrascosa
- EaStCHEM, School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, UK
| | - Darren Bellshaw
- EaStCHEM, School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, UK
| | - Nikola Zotev
- EaStCHEM, School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, UK
| | - Mengning Liang
- SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, CA 94025, USA
| | - Sergio Carbajo
- SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, CA 94025, USA
| | - Jason Koglin
- SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, CA 94025, USA
| | - Joseph S. Robinson
- SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, CA 94025, USA
| | - Sébastien Boutet
- SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, CA 94025, USA
| | - Adam Kirrander
- EaStCHEM, School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, UK
| | - Michael P. Minitti
- SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, CA 94025, USA
- Corresponding author. (P.M.W.); (M.P.M.)
| | - Peter M. Weber
- Department of Chemistry, Brown University, 324 Brook St., Providence, RI 02912, USA
- Corresponding author. (P.M.W.); (M.P.M.)
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7
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Yong H, Ruddock JM, Stankus B, Ma L, Du W, Goff N, Chang Y, Zotev N, Bellshaw D, Boutet S, Carbajo S, Koglin JE, Liang M, Robinson JS, Kirrander A, Minitti MP, Weber PM. Scattering off molecules far from equilibrium. J Chem Phys 2019; 151:084301. [PMID: 31470697 DOI: 10.1063/1.5111979] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Pump-probe gas phase X-ray scattering experiments, enabled by the development of X-ray free electron lasers, have advanced to reveal scattering patterns of molecules far from their equilibrium geometry. While dynamic displacements reflecting the motion of wavepackets can probe deeply into the reaction dynamics, in many systems, the thermal excitation embedded in the molecules upon optical excitation and energy randomization can create systems that encompass structures far from the ground state geometry. For polyatomic molecular systems, large amplitude vibrational motions are associated with anharmonicity and shifts of interatomic distances, making analytical solutions using traditional harmonic approximations inapplicable. More generally, the interatomic distances in a polyatomic molecule are not independent and the traditional equations commonly used to interpret the data may give unphysical results. Here, we introduce a novel method based on molecular dynamic trajectories and illustrate it on two examples of hot, vibrating molecules at thermal equilibrium. When excited at 200 nm, 1,3-cyclohexadiene (CHD) relaxes on a subpicosecond time scale back to the reactant molecule, the dominant pathway, and to various forms of 1,3,5-hexatriene (HT). With internal energies of about 6 eV, the energy thermalizes quickly, leading to structure distributions that deviate significantly from their vibrationless equilibrium. The experimental and theoretical results are in excellent agreement and reveal that a significant contribution to the scattering signal arises from transition state structures near the inversion barrier of CHD. In HT, our analysis clarifies that previous inconsistent structural parameters determined by electron diffraction were artifacts that might have resulted from the use of inapplicable analytical equations.
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Affiliation(s)
- Haiwang Yong
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Jennifer M Ruddock
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Brian Stankus
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Lingyu Ma
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Wenpeng Du
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Nathan Goff
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Yu Chang
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Nikola Zotev
- School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
| | - Darren Bellshaw
- School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
| | - Sébastien Boutet
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Sergio Carbajo
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Jason E Koglin
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Mengning Liang
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Joseph S Robinson
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Adam Kirrander
- School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
| | - Michael P Minitti
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Peter M Weber
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
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8
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Yong H, Zotev N, Stankus B, Ruddock JM, Bellshaw D, Boutet S, Lane TJ, Liang M, Carbajo S, Robinson JS, Du W, Goff N, Chang Y, Koglin JE, Waters MDJ, Sølling TI, Minitti MP, Kirrander A, Weber PM. Determining Orientations of Optical Transition Dipole Moments Using Ultrafast X-ray Scattering. J Phys Chem Lett 2018; 9:6556-6562. [PMID: 30380873 DOI: 10.1021/acs.jpclett.8b02773] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Identification of the initially prepared, optically active state remains a challenging problem in many studies of ultrafast photoinduced processes. We show that the initially excited electronic state can be determined using the anisotropic component of ultrafast time-resolved X-ray scattering signals. The concept is demonstrated using the time-dependent X-ray scattering of N-methyl morpholine in the gas phase upon excitation by a 200 nm linearly polarized optical pulse. Analysis of the angular dependence of the scattering signal near time zero renders the orientation of the transition dipole moment in the molecular frame and identifies the initially excited state as the 3p z Rydberg state, thus bypassing the need for further experimental studies to determine the starting point of the photoinduced dynamics and clarifying inconsistent computational results.
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Affiliation(s)
- Haiwang Yong
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
| | - Nikola Zotev
- School of Chemistry , University of Edinburgh , Edinburgh EH9 3FJ , United Kingdom
| | - Brian Stankus
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
| | - Jennifer M Ruddock
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
| | - Darren Bellshaw
- School of Chemistry , University of Edinburgh , Edinburgh EH9 3FJ , United Kingdom
| | - Sébastien Boutet
- SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
| | - Thomas J Lane
- SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
| | - Mengning Liang
- SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
| | - Sergio Carbajo
- SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
| | - Joseph S Robinson
- SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
| | - Wenpeng Du
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
| | - Nathan Goff
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
| | - Yu Chang
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
| | - Jason E Koglin
- SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
| | - Max D J Waters
- Department of Chemistry , University of Copenhagen , Universitetsparken 5 , 2100 Copenhagen , Denmark
| | - Theis I Sølling
- Department of Chemistry , University of Copenhagen , Universitetsparken 5 , 2100 Copenhagen , Denmark
| | - Michael P Minitti
- SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
| | - Adam Kirrander
- School of Chemistry , University of Edinburgh , Edinburgh EH9 3FJ , United Kingdom
| | - Peter M Weber
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
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Goff N. Getting ready for certification: let's get focused! Urol Nurs 1998; 18:147-8. [PMID: 9866643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Affiliation(s)
- N Goff
- Columbia Homecare, Tampa Bay, FL, USA
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10
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Goff N. Getting ready for certification. Urol Nurs 1996; 16:73-4. [PMID: 8826162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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11
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Goff N. My reconstruction period. Urol Nurs 1996; 16:27-8. [PMID: 8826393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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