Diffractive imaging of dissociation and ground-state dynamics in a complex molecule

Authors

• Kyle J. Wilkin, University of Nebraska–LincolnFollow
• Robert M. Parrish, SLAC National Accelerator Laboratory
• Jie Yang, SLAC National Accelerator Laboratory
• Thomas J.A. Wolf, Stanford University
• J. Pedro F. Nunes, University of Nebraska–Lincoln
• Markus Guehr, Stanford University
• Renkai Li, SLAC National Accelerator Laboratory
• Xiaozhe Shen, SLAC National Accelerator Laboratory
• Qiang Zheng, SLAC National Accelerator Laboratory
• Xijie Wang, SLAC National Accelerator Laboratory
• Todd J. Martinez, Stanford University
• Martin Centurion, University of Nebraska - LincolnFollow

Document Type

Article

Date of this Version

8-2-2019

Citation

PHYSICAL REVIEW A 100, 023402 (2019)

DOI: 10.1103/PhysRevA.100.023402

Comments

©2019 American Physical Society. Used by permission.

Abstract

We have investigated the structural dynamics in photoexcited 1,2-diiodotetrafluoroethane molecules (C₂F₄I₂) in the gas phase experimentally using ultrafast electron diffraction and theoretically using FOMO-CASCI excited-state dynamics simulations. The molecules are excited by an ultraviolet femtosecond laser pulse to a state characterized by a transition from the iodine 5p orbital to a mixed 5p||σ hole and CF₂• antibonding orbital, which results in the cleavage of one of the carbon-iodine bonds. We have observed, with sub-Angstrom resolution, the motion of the nuclear wave packet of the dissociating iodine atom followed by coherent vibrations in the electronic ground state of the C₂F₄I radical. The radical reaches a stable classical (nonbridged) structure in less than 200 fs.