Imaging CF3I conical intersection and photodissociation dynamics with ultrafast electron diffraction

Jie Yang; Xiaolei Zhu; Thomas J A Wolf; Zheng Li; J Pedro F Nunes; Ryan Coffee; James P Cryan; Markus Gühr; Kareem Hegazy; Tony F Heinz; Keith Jobe; Renkai Li; Xiaozhe Shen; Theodore Veccione; Stephen Weathersby; Kyle J Wilkin; Charles Yoneda; Qiang Zheng; Todd J Martinez; Martin Centurion; Xijie Wang

doi:10.1126/science.aat0049

Imaging CF₃I conical intersection and photodissociation dynamics with ultrafast electron diffraction

Science. 2018 Jul 6;361(6397):64-67. doi: 10.1126/science.aat0049.

Authors

Jie Yang^{1

2}, Xiaolei Zhu^{2

3}, Thomas J A Wolf², Zheng Li^{2

4

5}, J Pedro F Nunes⁶, Ryan Coffee^{2

7

8}, James P Cryan², Markus Gühr^{2

9}, Kareem Hegazy^{2

8}, Tony F Heinz^{2

10}, Keith Jobe¹¹, Renkai Li¹¹, Xiaozhe Shen¹¹, Theodore Veccione¹¹, Stephen Weathersby¹¹, Kyle J Wilkin¹², Charles Yoneda¹¹, Qiang Zheng¹¹, Todd J Martinez^{13

3}, Martin Centurion¹⁴, Xijie Wang¹

Affiliations

¹ SLAC National Accelerator Laboratory, Menlo Park, CA, USA. jieyang@slac.stanford.edu todd.martinez@stanford.edu martin.centurion@unl.edu wangxj@slac.stanford.edu.
² Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA.
³ Department of Chemistry, Stanford University, Stanford, CA, USA.
⁴ Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany.
⁵ Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany.
⁶ Department of Chemistry, University of York, Heslington, York, UK.
⁷ Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA, USA.
⁸ Department of Physics, Stanford University, Stanford, CA, USA.
⁹ Institut für Physik und Astronomie, Universität Potsdam, Potsdam, Germany.
¹⁰ Department of Applied Physics, Stanford University, Stanford, CA, USA.
¹¹ SLAC National Accelerator Laboratory, Menlo Park, CA, USA.
¹² Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, NE, USA.
¹³ Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA. jieyang@slac.stanford.edu todd.martinez@stanford.edu martin.centurion@unl.edu wangxj@slac.stanford.edu.
¹⁴ Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, NE, USA. jieyang@slac.stanford.edu todd.martinez@stanford.edu martin.centurion@unl.edu wangxj@slac.stanford.edu.

PMID: 29976821
DOI: 10.1126/science.aat0049

Abstract

Conical intersections play a critical role in excited-state dynamics of polyatomic molecules because they govern the reaction pathways of many nonadiabatic processes. However, ultrafast probes have lacked sufficient spatial resolution to image wave-packet trajectories through these intersections directly. Here, we present the simultaneous experimental characterization of one-photon and two-photon excitation channels in isolated CF₃I molecules using ultrafast gas-phase electron diffraction. In the two-photon channel, we have mapped out the real-space trajectories of a coherent nuclear wave packet, which bifurcates onto two potential energy surfaces when passing through a conical intersection. In the one-photon channel, we have resolved excitation of both the umbrella and the breathing vibrational modes in the CF₃ fragment in multiple nuclear dimensions. These findings benchmark and validate ab initio nonadiabatic dynamics calculations.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.