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.