Imaging CF₃I conical intersection and photodissociation dynamics with ultrafast electron diffraction

Authors

Jie Yang, SLAC National Accelerator Laboratory, Menlo Park, CAFollow
Xiaolei Zhu, SLAC National Accelerator Laboratory, Menlo Park, CA
Thomas J.A. Wolf, SLAC National Accelerator Laboratory, Menlo Park, CA
Zheng Li, SLAC National Accelerator Laboratory, Menlo Park, CA
J. Pedro F. Nunes, University of YorkFollow
Ryan Coffee, SLAC National Accelerator Laboratory, Menlo Park, CAFollow
James P. Cryan, SLAC National Accelerator Laboratory, Menlo Park, CAFollow
Markus Gühr, SLAC National Accelerator Laboratory, Menlo Park, CA
Kareem Hegazy, SLAC National Accelerator Laboratory, Menlo Park, CA
Tony F. Heinz, SLAC National Accelerator Laboratory, Menlo Park, CAFollow
Keith Jobe, SLAC National Accelerator Laboratory, Menlo Park, CA
Renkai Li, SLAC National Accelerator Laboratory, Menlo Park, CA
Xiaozhe Shen, SLAC National Accelerator Laboratory, Menlo Park, CA
Theodore Veccione, SLAC National Accelerator Laboratory, Menlo Park, CA
Stephen Weathersby, SLAC National Accelerator Laboratory, Menlo Park, CAFollow
Kyle J. Wilkin, University of Nebraska–LincolnFollow
Charles Yoneda, SLAC National Accelerator Laboratory, Menlo Park, CA
Qiang Zheng, SLAC National Accelerator Laboratory, Menlo Park, CA
Todd J. Martinez, SLAC National Accelerator Laboratory, Menlo Park, CAFollow
Martin Centurion, University of Nebraska - LincolnFollow
Xijie Wang, SLAC National Accelerator Laboratory, Menlo Park, CAFollow

Date of this Version

7-2018

Citation

Published in Science 361 (6 July 2018), pp 64–67.

doi 10.1126/science.aat0049

http://science.sciencemag.org/content/361/6397/64.long

Comments

Copyright © 2018 by the Authors; published by the American Association for the Advancement of Science. Used by permission.

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.

Includes supplementary materials.

Movie S1 attached below.