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

Authors

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

Document Type

Article

Date of this Version

8-2-2019

Citation

KYLE J. WILKIN et al. PHYSICAL REVIEW A 100, 023402 (2019). DOI: 10.1103/PhysRevA.100.023402

Comments

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 CF^•₂ 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.