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Title: Photodissociation dynamics of C{sub 3}H{sub 5}I in the near-ultraviolet region

The ultraviolet photodissociation dynamics of allyl iodide (C{sub 3}H{sub 5}I) have been studied by ion-imaging at 266 nm and 213 nm. These photolysis wavelengths are located in the two lowest absorption bands in the near-ultraviolet region. The atomic iodine products were detected by [2+1] resonantly enhanced multiphoton ionization spectroscopy. The spectra showed that the branching fraction for the spin-orbit excited ({sup 2}P{sub 1/2}) state was larger than that for the ground ({sup 2}P{sub 3/2}) state at both photolysis wavelengths. The state-resolved scattering images of iodine showed two maxima in the velocity distributions in the {sup 2}P{sub 3/2} state and a single peak in the {sup 2}P{sub 1/2} state. The spin-orbit specificity indicates that the C−I bond cleavage at both absorption bands is governed by the dissociative n{sub I}σ{sup *}{sub C−I} potential energy surfaces. The nascent internal energy distribution of the allyl radical (C{sub 3}H{sub 5}) counter product, which was obtained by the analysis of the state-resolved scattering distributions, showed a marked difference between the photolysis at 266 nm and 213 nm. The generation of the colder C{sub 3}H{sub 5} with the higher translational energy at 266 nm implied the direct photoexcitation to the n{sub I}σ{sup *}{sub C−I} repulsive surfaces, whereasmore » the internally hot C{sub 3}H{sub 5} at 213 nm was ascribed to the local π{sub CC}π{sup *}{sub CC} photoinitiation in the allyl framework followed by predissociation to the n{sub I}σ{sup *}{sub C−I} states.« less
Authors:
; ; ;  [1]
  1. Department of Chemistry, Graduate School of Science, Hiroshima University, Kagamiyama 1-3-1, Higashi-Hiroshima, Hiroshima 739-8526 (Japan)
Publication Date:
OSTI Identifier:
22308377
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 141; Journal Issue: 10; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ABSORPTION; ALLYL RADICALS; CLEAVAGE; ENERGY SPECTRA; IODIDES; IODINE; PEAKS; PHOTOIONIZATION; PHOTOLYSIS; POTENTIAL ENERGY; PREDISSOCIATION; SCATTERING; SPECIFICITY; SPECTROSCOPY; SPIN; SURFACES; WAVELENGTHS