Abstract
The photodissociation of propargyl chloride (C 3H 3Cl) has been studied at 193 nm. Ion imaging experiments with state-selective detection of the Cl atoms and single-photon ionization of the C 3H 3 radicals were performed, along with measurements of the Cl + C 3H 3 and HCl + C 3H 2 recoil kinetic energy distributions, using a scattering apparatus with electron bombardment ionization detection to resolve the competing Cl and HCl elimination channels. The experiments allow the determination of the Cl ( 2P 3/2) and Cl ( 2P 1/2) (hereafter Cl*) branching fractions associated with the C-Cl bond fission, which are determined to be 0.5 ± 0.1 for both channels. Although prior translational spectroscopy studies by others had concluded that the low velocity signal at the Cl+ mass was due to daughter fragments of the HCl elimination products, the present work shows that Cl atoms are produced with a bimodal recoil kinetic energy distribution. The major C-Cl bond fission channel, with a narrow recoil kinetic energy distribution peaking near 40 kcal/mol, produces both Cl and Cl*, whereas the minor (5%) channel, partitioning much less energy to relative kinetic energy, produces only ground spin - orbit state Cl atoms. The maximum internal energy of the radicals produced in the lowrecoil-kinetic-energy channel is consistent with this channel producing electronically excited propargyl radicals. Finally, in contrast to previous studies, the present work determines the HCl recoil kinetic energy distribution and identifies the possible contribution to this spectrum from propargyl radicals cracking to C 3 + ions in the mass spectrometer.
| Original language | English |
|---|---|
| Pages (from-to) | 843-850 |
| Number of pages | 8 |
| Journal | Journal of Physical Chemistry A |
| Volume | 110 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - Feb 26 2006 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Physical and Theoretical Chemistry
Cite this
Photodissociation of propargyl chloride at 193 nm. / McCunn, Laura R.; Bennett, Doran I G; Butler, Laurie J.; Fan, Haiyan; Aguirre, Fernando; Pratt, Stephen T.
In: Journal of Physical Chemistry A, Vol. 110, No. 3, 26.02.2006, p. 843-850.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Photodissociation of propargyl chloride at 193 nm
AU - McCunn, Laura R.
AU - Bennett, Doran I G
AU - Butler, Laurie J.
AU - Fan, Haiyan
AU - Aguirre, Fernando
AU - Pratt, Stephen T.
PY - 2006/2/26
Y1 - 2006/2/26
N2 - The photodissociation of propargyl chloride (C 3H 3Cl) has been studied at 193 nm. Ion imaging experiments with state-selective detection of the Cl atoms and single-photon ionization of the C 3H 3 radicals were performed, along with measurements of the Cl + C 3H 3 and HCl + C 3H 2 recoil kinetic energy distributions, using a scattering apparatus with electron bombardment ionization detection to resolve the competing Cl and HCl elimination channels. The experiments allow the determination of the Cl ( 2P 3/2) and Cl ( 2P 1/2) (hereafter Cl*) branching fractions associated with the C-Cl bond fission, which are determined to be 0.5 ± 0.1 for both channels. Although prior translational spectroscopy studies by others had concluded that the low velocity signal at the Cl+ mass was due to daughter fragments of the HCl elimination products, the present work shows that Cl atoms are produced with a bimodal recoil kinetic energy distribution. The major C-Cl bond fission channel, with a narrow recoil kinetic energy distribution peaking near 40 kcal/mol, produces both Cl and Cl*, whereas the minor (5%) channel, partitioning much less energy to relative kinetic energy, produces only ground spin - orbit state Cl atoms. The maximum internal energy of the radicals produced in the lowrecoil-kinetic-energy channel is consistent with this channel producing electronically excited propargyl radicals. Finally, in contrast to previous studies, the present work determines the HCl recoil kinetic energy distribution and identifies the possible contribution to this spectrum from propargyl radicals cracking to C 3 + ions in the mass spectrometer.
AB - The photodissociation of propargyl chloride (C 3H 3Cl) has been studied at 193 nm. Ion imaging experiments with state-selective detection of the Cl atoms and single-photon ionization of the C 3H 3 radicals were performed, along with measurements of the Cl + C 3H 3 and HCl + C 3H 2 recoil kinetic energy distributions, using a scattering apparatus with electron bombardment ionization detection to resolve the competing Cl and HCl elimination channels. The experiments allow the determination of the Cl ( 2P 3/2) and Cl ( 2P 1/2) (hereafter Cl*) branching fractions associated with the C-Cl bond fission, which are determined to be 0.5 ± 0.1 for both channels. Although prior translational spectroscopy studies by others had concluded that the low velocity signal at the Cl+ mass was due to daughter fragments of the HCl elimination products, the present work shows that Cl atoms are produced with a bimodal recoil kinetic energy distribution. The major C-Cl bond fission channel, with a narrow recoil kinetic energy distribution peaking near 40 kcal/mol, produces both Cl and Cl*, whereas the minor (5%) channel, partitioning much less energy to relative kinetic energy, produces only ground spin - orbit state Cl atoms. The maximum internal energy of the radicals produced in the lowrecoil-kinetic-energy channel is consistent with this channel producing electronically excited propargyl radicals. Finally, in contrast to previous studies, the present work determines the HCl recoil kinetic energy distribution and identifies the possible contribution to this spectrum from propargyl radicals cracking to C 3 + ions in the mass spectrometer.
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U2 - 10.1021/jp058148y
DO - 10.1021/jp058148y
M3 - Article
VL - 110
SP - 843
EP - 850
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
SN - 1089-5639
IS - 3
ER -