A classical approach to dissociative electron attachment DA: application to temperature effects in the DA cross section of CF3Cl

Lehr, L.; Miller, William H.

doi:10.1016/0009-2614(96)00037-1

Cited by 46 publications

(41 citation statements)

References 25 publications

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“…Due to the reciprocal energy dependence of the attachment cross section, however, these features appear at zero eV and are reminiscent of DEA reactions at low energies. [25][26][27] They reflect transition from vibrational excited levels and thus exhibit a strong temperature dependence. Although these levels may only weakly be populated via the Boltzmann distribution, they can result in appreciable signals due to the reciprocal energy dependence.…”

Section: Resultsmentioning

confidence: 99%

Formation of anion fragments from gas-phase glycine by low energy (0–15 eV) electron impact

Gohlke

Rosa

Illenberger

et al. 2002

The Journal of Chemical Physics

114

105

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Dissociative electron attachment to pentaerythritol tetranitrate: Significant fragmentation near 0 eV Absolute partial cross sections for electron-impact ionization of CH4 from threshold to 1000 eV We have measured the formation of anion fragments in gas phase glycine (H 2 NCH 2 COOH) via dissociative electron attachment ͑DEA͒ reactions in the 0-15 eV electron energy range, using a monochromatic electron beam and mass spectrometric detection of the negative ions. By far the most intense product observed is the closed shell glycine anion (H 2 NCH 2 COO) Ϫ which appears from a low-energy resonance with a peak located at 1.4 eV and a cross section in the range 10 Ϫ16 cm 2 . The corresponding precursor ion can be characterized by electron attachment into the empty * orbital of the ϪCOOH group as recently assigned from electron transmission experiments and ab initio self-consistent field calculations ͓Aflatooni, Hitt, Gallup, and Burrow, J. Chem. Phys. 115, 6489 ͑2001͔͒. This precursor state is also observed to decompose ͑with much lower intensity͒ yielding a negative ion fragment with 58 amu, which is attributed to anions of the stoichiometric composition H 2 C 2 O 2Ϫ or H 4 C 2 NO Ϫ . A further prominent DEA peak is observed at 6 eV, which is likely associated with a core excited resonance, and leads to formation of at least six different negative ion fragment species with the following mass numbers: 16 amu (O Ϫ /NH 2 Ϫ ), 17 amu (OH Ϫ ), 26 amu (CN Ϫ ), 28 amu (H 2 CN Ϫ ), 45 amu (HCO 2 Ϫ ), 56 amu (H 2 C 2 NO Ϫ ).

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Section: Resultsmentioning

confidence: 99%

Formation of anion fragments from gas-phase glycine by low energy (0–15 eV) electron impact

Gohlke

Rosa

Illenberger

et al. 2002

The Journal of Chemical Physics

114

105

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“…33,34 Figure 4 shows the relative cross section curve for the formation of ClHF − from CClF 2 COOH (not reported in the previous study on electron attachment to CClF 2 COOH (Refs. 17 and 18)) and ClHCl − from CCl 3 COOH.…”

Section: B Loss Of a Neutral Hydrogen Atom Cleavage Of The C-f Bondmentioning

confidence: 99%

Low energy (0–10 eV) electron driven reactions in the halogenated organic acids CCl3COOH, CClF2COOH, and CF3CHNH2COOH (trifluoroalanine)

Kopyra

König-Lehmann

Illenberger

2011

The Journal of Chemical Physics

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Negative ion formation following resonant electron attachment to the three title molecules is studied by means of a beam experiment with mass spectrometric detection of the anions. All three molecules exhibit a pronounced resonance in the energy range around 1 eV which decomposes by the loss of a neutral hydrogen atom thereby generating the closed shell anion (M-H)(-) (or RCOO(-)), a reaction which is also a common feature in the non-substituted organic acids. The two chlorine containing molecules CCl(3)COOH and CClF(2)COOH exhibit an additional strong and narrow resonance at very low energy (close to 0 eV) which decomposes by the cleavage of the C-Cl bond with the excess charge finally localised on either of the two fragments Cl(-) and (M-Cl)(-). This reaction is by two to three orders of magnitude more effective than hydrogen loss. Apart from these direct bond cleavages (C-Cl, O-H) resonant attachment of subexcitation electrons trigger additional remarkably complex unimolecular decompositions leading, e.g., to the formation of the bihalide ions ClHCl(-) and ClHF(-) from CCl(3)COOH and CClF(2)COOH, respectively, or the loss of a neutral CF(2) unit from trifluoroalanine thereby generating the fluoroglycine radical anion. These reactions require substantial rearrangement in the transitory negative ion, i.e., the cleavage of different bonds and formation of new bonds. F(-) from both chlorodifluoroacetic acid and trifluoroalanine is formed at comparatively low intensity (more than three orders of magnitude less than Cl(-) from the chlorine containing molecules) and predominantly within a broad resonant feature around 7-8 eV characterised as core excited resonance.

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“…A strong temperature effect in DA to CF 3 Cl was detected by Hahndorf et al (1994) in the low-energy region (energy width around 0.1 eV). Theoretical calculations have been performed in the classical approximation (Lehr and Miller 1996;Lehr et al, 1997) and by the use of the resonance R-matrix method . Recent ab initio calculations of Beyer et al (2001) combine the R-matrix method with the projection operator technique to treat the vibrational dynamics.…”

Section: A2 Methyl Halides and Related Moleculesmentioning

confidence: 99%

Resonance and Threshold Phenomena in Low-Energy Electron Collisions with Molecules and Clusters

Hotop

Ruf

Allan

et al. 2003

Advances in Atomic, Molecular, and Optical Physics

269

229

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A classical approach to dissociative electron attachment DA: application to temperature effects in the DA cross section of CF3Cl

Cited by 46 publications

References 25 publications

Formation of anion fragments from gas-phase glycine by low energy (0–15 eV) electron impact

Formation of anion fragments from gas-phase glycine by low energy (0–15 eV) electron impact

Low energy (0–10 eV) electron driven reactions in the halogenated organic acids CCl3COOH, CClF2COOH, and CF3CHNH2COOH (trifluoroalanine)

Resonance and Threshold Phenomena in Low-Energy Electron Collisions with Molecules and Clusters

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