skip to main content

Title: Communication: Ultraviolet photodissociation dynamics of the simplest Criegee intermediate CH{sub 2}OO

The velocity and angular distributions of O {sup 1}D photofragments arising from UV excitation of the CH{sub 2}OO intermediate on the B {sup 1}A′←X {sup 1}A′ transition are characterized using velocity map ion imaging. The anisotropic angular distribution yields the orientation of the transition dipole moment, which reflects the π*←π character of the electronic transition associated with the COO group. The total kinetic energy release distributions obtained at several photolysis wavelengths provide detail on the internal energy distribution of the formaldehyde cofragments and the dissociation energy of CH{sub 2}OO X {sup 1}A′ to O {sup 1}D + H{sub 2}CO X {sup 1}A{sub 1}. A common termination of the total kinetic energy distributions, after accounting for the different excitation energies, gives an upper limit for the CH{sub 2}OO X {sup 1}A′ dissociation energy of D{sub 0}≤ 54 kcal mol{sup −1}, which is compared with theoretical predictions including high level multi-reference ab initio calculations.
Authors:
; ; ;  [1]
  1. Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323 (United States)
Publication Date:
OSTI Identifier:
22224135
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 139; Journal Issue: 14; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; ANGULAR DISTRIBUTION; ANISOTROPY; DIPOLE MOMENTS; DISSOCIATION; DISSOCIATION ENERGY; ENERGY SPECTRA; EXCITATION; EXCITED STATES; FORMALDEHYDE; KINETIC ENERGY; PHOTOLYSIS; PHOTON-MOLECULE COLLISIONS