Elsevier

Chemical Physics

Volume 31, Issue 2, 15 June 1978, Pages 273-280
Chemical Physics

Lifetimes of the vibronic Ã2A1 states of H2O+ and of the 3Πi (υ′ = 0) state of OH+

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Abstract

Using the delayed coincidence technique, lifetimes have been measured for some Σ and Π vibronic Ã2A1 states of H2O+ and for the 3Πi (υ′ = 0) state of OH+ by analysing the decay curves of the Ã2A1(0, υ′2, 0) ⇌ X̃2B1 (0, υ″2, 0) and the 3Πi(υ′ = 0) ⇌ 3Σ(υ″ = 0) emission intensities respectively. The excited molecular ionic states are produced via excitation of H2O molecules by 200 eV electrons. For H2O+2A1) the vibronic Σ levels with υ′2 = 13 and 15 and the vibronic Π levels with υ′2 = 12 and 14 have been considered. The radiative lifetimes obtained for these levels have about the same value, namely 10.5(±1) × 10−6 s. The radiative lifetime for the OH+(3Πiυ′= 0) state is 2.5(±0.3) × 10−6 s. The lifetimes found in this work for H2O+2A1) and OH+(3Πi,υ′= 0) are about ten and three times longer respectively than the corresponding lifetimes given by other investigators [1,2]. The probable reason for this discrepancy is that in the other experiments no attention has been paid to the presence of a large space charge effect. This effect is caused by the positive ions which are created by the primary electron beam.

References (19)

  • R.W.B. Pearse et al.
    (1965)
  • G.R. Möhlmann et al.

    Chem. Phys. Letters

    (1976)
  • L.J. Curtis et al.

    Physica Scripta

    (1977)
  • L.J. Curtis et al.

    J. Opt. Soc. Am.

    (1977)
  • P. Erman et al.

    Phys. Letters

    (1973)
  • J. Brzozowski et al.

    Physica Scripta

    (1974)
  • K.R. German

    J. Chem. Phys.

    (1975)
  • H. Lew et al.

    J. Chem. Phys.

    (1973)
    H. Lew

    Can. J. Phys.

    (1976)
  • J.A. Pople et al.

    Mol. Phys.

    (1958)
There are more references available in the full text version of this article.

Cited by (33)

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1

Department of Theoretical Organic Chemistry, Leyden University, The Netherlands. Present address: AKZO Res. Labs Arnhem, The Netherlands.

2

J.K. Institute, Allahabad University, India.

3

Physics Department, Osaka University, Japan.

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