The Photochemistry of cis-Stilbene Studied by Ultrafast Electron Diffraction

ORAL

Abstract

Stilbene is a model system for studying both photoisomerization and photocyclization mechanisms, commonly pivotal to the conversion of light into chemical and mechanical energy in nature. Despite multi-decades of research, the exact details of the photoisomerization of cis-stilbene into trans-stilbene and/or its cyclization into 4a,4b-dihydrophenanthrene (DHP) have remained a topic of debate. Here we used megaelectronvolt ultrafast electron diffraction (UED) to capture and spatially resolve the photoisomerization and/or photocyclization of cis stilbene with sub-angstrom resolution and shed some light on the mechanisms mediating its rich photochemistry. At the SLAC MeV-UED beamline, cis-stilbene was optically pumped with 267 nm ultraviolet light and probed with 3.7 MeV electrons. Analyses of the difference-diffraction signals revealed features across a wide momentum transfer range, up to 8Å-1. These features were found to be in good qualitative agreement with the difference signal predicted by Ab initio multiple spawning simulations.

*This work was supported by the U.S. Department of Energy, Office of Science,Basic Energy Sciences, under Award # DE-SC0014170.

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Presenters

  • Sajib Kumar Saha

    • Department of Physics and Astronomy, University of Nebraska- Lincoln, Lincoln, NE, USA.
    • UNIVERSITY OF NEBRASKA LINCOLN

Authors

  • Sajib Kumar Saha

    • Department of Physics and Astronomy, University of Nebraska- Lincoln, Lincoln, NE, USA.
    • UNIVERSITY OF NEBRASKA LINCOLN

  • Pedro Nunes

    • Department of Physics and Astronomy, University of Nebraska- Lincoln, Lincoln, NE, USA
    • UNIVERSITY OF NEBRASKA LINCOLN
    • SLAC National Accelerator Laboratory
    • University of Nebraska-Lincoln

  • Hayley Weir

    • Department of Chemistry, Stanford University, Stanford, CA, USA.

  • Bryan Moore

    • Department of Physics and Astronomy, University of Nebraska- Lincoln, Lincoln, NE, USA

  • Monika Willams

    • Department of Chemistry, Stanford University, Stanford, CA, USA.

  • Andrew Attar

    • SLAC National Accelerator Laboratory, Menlo Park, CA, USA.
    • SLAC National Accelerator Laboratory

  • Duan Luo

    • SLAC National Accelerator Laboratory, Menlo Park, CA, USA.

  • Ming-Fu Lin

    • SLAC - Natl Accelerator Lab
    • SLAC National Accelerator Laboratory

  • Matthias Hoffmann

    • SLAC National Accelerator Laboratory, Menlo Park, CA, USA.

  • Jie Yang

    • SLAC National Accelerator Laboratory, Menlo Park, CA, USA.

  • Fuhao Ji

    • SLAC National Accelerator Laboratory, Menlo Park, CA, USA.

  • Matthew R Ware

    • Stanford Univ
    • Stanford University

  • Keith Jobe

    • SLAC National Accelerator Laboratory, Menlo Park, CA, USA.

  • Shashank Pathak

    • Kansas State University
    • J. R. Macdonald Laboratory, Physics Department, Kansas State University, Manhattan, KS, US

  • Thomas J Wolf

    • SLAC - Natl Accelerator Lab
    • SLAC National Accelerator Laboratory
    • SLAC - National Accelerator Laboratory

  • Todd Martinez

    • Department of Chemistry, Stanford University, Stanford, CA, USA.

  • Martin Centurion

    • Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, NE,US
    • University of Nebraska - Lincoln