Investigating dissociation pathways in photoinduced NO abstraction from nitrobenzene via electron diffraction

POSTER

Abstract

Nitrobenzene has a rich and complex photochemistry, which is, however, not well understood. In particular, the photochemical NO abstraction has been thought to undergo a roaming style reaction. Such roaming mechanisms are thought to be an important unimolecular reaction where the fragments “roam” around each other before they react and reorganize. Here we directly observe the time dependent structural evolution of gas phase nitrobenzene pumped with 266 nm light at the SLAC Ultrafast Electron Diffraction facility, with 0.5 Å and 150 fs spatial and temporal resolution, respectively. As the first sub-picosecond geometric probe of nitrobenzene’s dynamics we investigate how its nuclear structure changes as the molecule undergoes its complex photochemical dynamics. We find that nitrobenzene quickly relaxes to the ground state within the first picosecond, indicating that subsequent dissociations are thermally driven and take place in the singlet state.

*UED is supported in part by DOE BES Scientific User Facilities Division and SLAC UED/UEM program development: DE-AC02-05CH11231. This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division.

Presenters

  • Kareem Hegazy

    • Stanford Univ
    • Stanford Univ; Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA

Authors

  • Kareem Hegazy

    • Stanford Univ
    • Stanford Univ; Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA

  • Monika Williams

    • Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA

  • Renkai Li

    • Department of Engineering Physics, Tsinghua University, Beijing 100084, China

  • Ming-Fu Lin

    • SLAC - Natl Accelerator Lab
    • LCLS, SLAC National Accelerator Laboratory, Menlo Park, CA, USA

  • Brian Moore

    • Department of Physics and Astronomy, University of Nebraska, 855 N 16th Street, Lincoln, NE 68588, USA

  • Pedro Nunes

    • University of Nebraska, Lincoln
    • Department of Physics and Astronomy, University of Nebraska, 855 N 16th Street, Lincoln, NE 68588, USA

  • Xiaozhe Shen

    • SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA

  • Stephen Weathersby

    • SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA

  • Xijie Wang

    • SLAC National Lab
    • SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA

  • Jie Yang

    • Tsinghua University
    • Department of Engineering Physics, Tsinghua University, Beijing 100084, China

  • Thomas J Wolf

    • SLAC - Natl Accelerator Lab
    • LCLS, SLAC National Accelerator Laboratory, Menlo Park, CA, USA