Rotationally resolved pulsed field ionization photoelectron bands for O{sub 2}{sup +}(a {sup 4}{pi}{sub u}, v{sup +}=0-18) in the energy range of 16.0-18.0 eV

Journal Article · Sat Jan 15 00:00:00 EST 2000 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.480682· OSTI ID:20215054

Song, Y ^[1]; Evans, M ^[1]; Ng, C Y ^[1]; Hsu, C -W ^[2]; Jarvis, G K ^[2]

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1. Ames Laboratory, USDOE and Department of Chemistry, Iowa State University, Ames, Iowa 50011 (United States)
2. Chemical Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

We have obtained rotationally resolved pulsed field ionization-photoelectron (PFI-PE) spectra of O{sub 2} in the energy range of 16.0-18.0 eV, covering ionization transitions O{sub 2}{sup +}(a {sup 4}{pi}{sub u}, v{sup +}=0-18,J{sup +})(<-)O{sub 2}(X {sup 3}{sigma}{sub g}{sup .}, v{sup ''}=0,N{sup ''}). Although these vibrational PFI-PE bands for O{sub 2}{sup +}(a {sup 4}{pi}{sub u}, v{sup +}) have significant overlaps with those for O{sub 2}{sup +}(X {sup 2}{pi}{sub g}) and O{sub 2}{sup +}(A {sup 2}{pi}{sub u}), we have identified all O{sub 2}{sup +}(a {sup 4}{pi}{sub u}, v{sup +}=0-18) bands by simulation of spectra obtained using supersonically cooled O{sub 2} samples with rotational temperatures {approx_equal}20 and 220 K. While the v{sup +}=4-18PFI-PE bands represent the first rotationally resolved photoelectron data for O{sub 2}{sup +}(a {sup 4}{pi}{sub u}), the PFI-PE bands for O{sub 2}{sup +}(a {sup 4}{pi}{sub u}, v{sup +}=10-18) are the first rotationally resolved spectroscopic data for these levels. The simulation also allows the determination of accurate ionization energies, vibrational constants, and rotational constants for O{sub 2}{sup +}(a {sup 2}{pi}{sub u}, v{sup +}=0-18). The observed intensities of spin-orbit components for the majority of O{sub 2}{sup +}(a {sup 2}{pi}{sub u}, v{sup +}) vibrational bands are in accordance with the forced spin-orbit/rotational autoionization mechanism. (c) 2000 American Institute of Physics.

• OSTI ID: 20215054
• Journal Information: Journal of Chemical Physics, Vol. 112, Issue 3; Other Information: PBD: 15 Jan 2000; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
PHOTOELECTRON SPECTROSCOPY
OXYGEN IONS
CATIONS
MOLECULAR IONS
ROTATIONAL STATES
VIBRATIONAL STATES
PHOTOIONIZATION
IONIZATION POTENTIAL
L-S COUPLING
EXPERIMENTAL DATA
THEORETICAL DATA