The Ring-Closing Reaction of Cyclopentadiene Probed with Ultrafast X‑ray Scattering

Authors

• Lisa Huang, Brown University
• Lauren Bertram, University of Oxford
• Lingyu Ma, Brown University
• Nathan Goff, Brown University
• Stuart W. Crane, Brown University
• Asami Odate, Brown University
• Thomas Northey, Brown University
• Andrés Moreno Carrascosa, University of Oxford
• Mats Simmermacher, University of Oxford
• Sri Bhavya Muvva, University of Nebraska - LincolnFollow
• Joseph D. Geiser, Brown University
• Matthew J. Lueckheide, Brown University
• Zane Phelps, Kansas State University
• Mengning Liang, SLAC National Accelerator Laboratory
• Xinxin Cheng, SLAC National Accelerator Laboratory
• Ruaridh Forbes, SLAC National Accelerator Laboratory
• Joseph S. Robinson, AC National Accelerator Laboratory
• Matthew J. Hayes, SLAC National Accelerator Laboratory
• Felix Allum, SLAC National Accelerator Laboratory
• Alice E. Green, SLAC National Accelerator Laboratory
• Kenneth Lopata, Louisiana State University
• Artem Rudenko, Kansas State University
• Thomas J. A. Wolf, SLAC National Accelerator Laboratory
• Martin Centurion, University of Nebraska - LincolnFollow
• Daniel Rolles, Kansas State University
• Michael P. Minitti, SLAC National Accelerator Laboratory
• Adam Kirrander, University of Oxford
• Peter M. Weber, Brown University

Document Type

Article

Date of this Version

5-6-2024

Citation

J. Phys. Chem. A 2024, 128, 4992−4998

Comments

Open access.

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.