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.