Effect of Temperature on Electron Attachment to and Negative Ion States of CCl2F2

Published

November 1, 1998

Author(s)

Yicheng Wang, Loucas G. Christophorou, J. K. Verbrugge

Abstract

The effect of temperature on electron attachment to dichlorodifluoromethane (CCl₂F₂) has been investigated for temperatures up to 500 K and for mean electron energies from thermal to 1.0 eV using an electron swarm method. The measurements were made in mixtures of CCl₂F₂ with nitrogen. The electron attachment rate constant increases with temperature over the entire temperature and mean-electron energy range investigated. The variation of the thermal value of the electron attachment rate constant with temperature compares well with earlier measurements of this quantity and shows an increase by a factor of 10 when the temperature is raised from 300 K to 500 K. From a comparison of published data on the electron affinity, electron attachment using the swarm method, electron attachment using the electron beam method, electron scattering, electron transmission, indirect electron scattering, and related calculations, the lowest negative ion states of CCl₂F₂ have been identified with average positions as follows: a₁ (C-Clς*) at + 0.4 eV and -0.9 eV, b₂ (C-Clς*) at - 2.5 eV, a₁ (C-Fς*) at -3.5 eV, and b₁ (C-Fς*) at -6.2 eV; an electron-excited Feshbach resonance is also indicated at -8.9 eV.

Citation

Journal of Chemical Physics

Volume

109

Issue

19

Pub Type

Journals

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Keywords

attachment, attachment rate constant, CCl2F2, dichlorodifluoromethane, temperature effect

Citation

Wang, Y. , Christophorou, L. and Verbrugge, J. (1998), Effect of Temperature on Electron Attachment to and Negative Ion States of CCl₂F₂, Journal of Chemical Physics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=13721 (Accessed May 15, 2024)