Production of vibrationally autodetaching in low-energy electron impact on ozone

Abstract

Attachment of electrons with energies of 1.2 to 2 eV to ozone was found to lead to the production of O and vibrationally excited , the latter subsequently lose electrons by vibrational autodetachment. This type of electron scattering is intermediate between inelastic electron scattering and dissociative attachment. Spectra of the detached electrons have resolved vibrational structure, which can be assigned to the individual vibronic transitions, providing detailed information on the product state distribution. The absolute integral cross section for the production of in vibrational states was found to be substantial, for example at 1.7 eV it is (with an error bar of about and ). Measurements of the signal onsets permit an independent determination of the dissociation energy of ozone into O and with the result eV. Comparison of the peak width of the electrons detached by in this work with the width of peaks of resonances observed in electron- scattering indicates a moderate degree of rotational excitation in the present process.

Determination of the Effective Ground State Potential Energy Function of Ozone from High-Resolution Infrared Spectra

“…8b. It is seen that the dissociation energy for this cut, D 0 ϭ 1.06 eV, is in excellent agreement with the experimental value D 0 ϭ 1.06 Ϯ 0.04 eV measured in low energy electronic impact experiments (81), and with the accepted thermodynamic value of D 0 ϭ 1.05 Ϯ 0.02 eV (82). These two experimental values were recommended in a recent review (3) as the most consistent ones, even though there exist other experimental determinations giving somewhat lower dissociation energies (83).…”

“…(19) give the value of the dissociation limit D e ϭ 0.91 eV (counted from the global minimum), which is lowered by 22% relative to our value and clearly is lower than the experimental values of Refs. (81,82).…”

Absolute cross sections for dissociative electron attachment to HCN and DCN

“…This is in contrast to the CO 2 case where the threshold structure could be made to appear much more clearly in this way [20]. Vibrationally excited fragment anions have been detected also in the case of the O 2 − /O 3 [25] except that the much lower electron affinity of O 2 (0.44 eV) made the vibrationally excited O 2 − autodetach-it was detected by the emitted electrons.…”

The high sensitivity absorption spectrum of ozone (18O3 and 16O3) near 7800cm−1: Identification of the 3A2(000)–X(110) hot band superimposed to very weak vibrational bands

“…Considerable efforts have been devoted to the determination of the X 1 A 1 ground electronic state PES by ab initio calculations [1][2][3] or through a fit to experimental rovibrational data [4,5]. A value of the dissociation energy D 0 % 8480 cm À1 was experimentally determined by low energy electron impact [6] in excellent agreement with its thermodynamic determination [7] but the characterization of the high lying vibrational states suffers from a lack of experimental data. This is a consequence of the rapid decrease of the band strengths with the excitation energy: the strongest vibrational bands near 7000 cm À1 are eight orders of magnitude weaker than the v 3 fundamental.…”