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

Journal Article · · Physical Review A
 [1];  [2];  [3];  [4];  [5];  [6];  [7];  [7];  [7];  [7];  [4];  [1]
  1. Univ. of Nebraska, Lincoln, NE (United States). Dept. of Physics and Astronomy
  2. SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford PULSE Institute, Menlo Park CA (United States); Stanford Univ., CA (United States). Dept. of Chemistry
  3. SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford PULSE Institute, Menlo Park CA (United States)
  4. Stanford PULSE Institute, Menlo Park CA (United States)
  5. Univ. of Nebraska, Lincoln, NE (United States). Dept. of Physics and Astronomy; Univ. of York (United Kingdom). Dept. of Chemistry
  6. Stanford PULSE Institute, Menlo Park CA (United States); Univ. Potsdam, Potsdam (Germany). Inst. für Physik und Astronomie
  7. SLAC National Accelerator Lab., Menlo Park, CA (United States)
+ Show Author Affiliations

We have investigated the structural dynamics in photoexcited 1,2-diiodotetrafluoroethane molecules $$(C_2F_4I_2)$$ 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 $$C_2F_4I_2$$ radical. The radical reaches a stable classical (nonbridged) structure in less than 200 fs.

Research Organization:
SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Univ. of Nebraska, Lincoln, NE (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences & Biosciences Division; Volkswagen Foundation
Grant/Contract Number:
AC02-05-CH11231; AC02-76SF00515; SC0014170; AC02-05CH11231
OSTI ID:
1560631
Alternate ID(s):
OSTI ID: 1546834; OSTI ID: 1671786
Journal Information:
Physical Review A, Vol. 100, Issue 2; ISSN 2469-9926
Publisher:
American Physical Society (APS)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 18 works
Citation information provided by
Web of Science

References (32)

Femtosecond Elimination Reaction Dynamics journal June 1997
Ultraviolet photodissociation and thermochemistry of CH 2 BrCH 2 I, CF 2 BrCF 2 I, and CF 2 ICF 2 I journal June 1989
Imaging CF 3 I conical intersection and photodissociation dynamics with ultrafast electron diffraction journal July 2018
Ab initio floating occupation molecular orbital-complete active space configuration interaction: An efficient approximation to CASSCF journal June 2010
Ultrafast Electron Diffraction and Structural Dynamics:  Transient Intermediates in the Elimination Reaction of C 2 F 4 I 2 journal April 2002
The photochemical ring-opening of 1,3-cyclohexadiene imaged by ultrafast electron diffraction journal April 2019
Nonadiabatic Ab Initio Molecular Dynamics with the Floating Occupation Molecular Orbital-Complete Active Space Configuration Interaction Method journal December 2017
Ab initio energy-adjusted pseudopotentials for elements of groups 13–17 journal December 1993
Imaging of Isolated Molecules with Ultrafast Electron Pulses journal September 2012
Imaging of alignment and structural changes of carbon disulfide molecules using ultrafast electron diffraction journal September 2015
Analytic formulation of derivative coupling vectors for complete active space configuration interaction wavefunctions with floating occupation molecular orbitals journal November 2016
Time-Resolved Electron Diffraction from Selectively Aligned Molecules journal May 2009
Density Functional and ab Initio Investigation of CF 2 ICF 2 I and CF 2 CF 2 I Radicals in Gas and Solution Phases journal October 2009
Mega-electron-volt ultrafast electron diffraction at SLAC National Accelerator Laboratory journal July 2015
Imaging of Ultrafast Molecular Elimination Reactions journal January 2006
CF 2 XCF 2 X and CF 2 XCF 2 • Radicals (X = Cl, Br, I):  Ab Initio and DFT Studies and Comparison with Experiments journal March 2001
Impulsive solvent heating probed by picosecond x-ray diffraction journal March 2006
Ultrafast electron diffraction: structures in dissociation dynamics of Fe(CO)5 journal December 1997
Picosecond photofragment spectroscopy. IV. Dynamics of consecutive bond breakage in the reaction C 2 F 4 I 2 →C 2 F 4 + 2I journal January 1990
Diffractive imaging of a rotational wavepacket in nitrogen molecules with femtosecond megaelectronvolt electron pulses journal April 2016
Capturing Transient Structures in the Elimination Reaction of Haloalkane in Solution by Transient X-ray Diffraction journal May 2008
Oriented Ensembles in Ultrafast Electron Diffraction journal June 2006
Femtosecond electron diffraction: heralding the era of atomically resolved dynamics journal August 2011
Ultrafast electron diffraction and direct observation of transient structures in a chemical reaction journal January 1999
Conformations and Barriers of Haloethyl Radicals (CH 2 XCH 2 , X = F, Cl, Br, I):  Ab Initio Studies journal August 1999
Picosecond monitoring of a chemical reaction in molecular beams: Photofragmentation of R–I→R ‡ +I journal August 1985
Direct Imaging of Transient Molecular Structures with Ultrafast Diffraction journal January 2001
Diffractive Imaging of Coherent Nuclear Motion in Isolated Molecules journal October 2016
Ultrafast Electron Diffraction: Oriented Molecular Structures in Space and Time journal November 2005
Ultrafast X-ray Diffraction of Transient Molecular Structures in Solution journal August 2005
Photodissociation Reaction of 1,2-Diiodoethane in Solution:  A Theoretical and X-ray Diffraction Study journal November 2005
Conformational analysis. 15. 1,2-Dibromotetrafluoroethane and 1,2-diiodotetrafluoroethane. Electron diffraction investigations of the molecular structures, compositions, and anti-gauche energy and entropy differences journal April 1992

Figures / Tables (11)

FIG. 1(p. 2)figure FIG. 1
FIG. 2(p. 2)figure FIG. 2
FIG. 3(p. 3)figure FIG. 3
FIG. 4(p. 3)figure FIG. 4
FIG. 5(p. 4)figure FIG. 5
FIG. 6(p. 4)figure FIG. 6
FIG. 7(p. 6)figure FIG. 7
FIG. 8(p. 8)figure FIG. 8
FIG. 10(p. 9)figure FIG. 10
FIG. 9(p. 9)figure FIG. 9
FIG. 11(p. 10)figure FIG. 11

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