Multiplet-specific shape resonance and autoionization effects in (2+1) resonance enhanced multiphoton ionization of O_2 via the d ^1Π_g state
- Creators
- Stephens, J. A.
- Braunstein, M.
- McKoy, V.
Abstract
In this paper we discuss the single‐photon ionization dynamics of the d ^1Π_g Rydberg state of O_2. Comparison is made with vibrationally resolved measurements of photoelectron spectra which employ (2+1) resonance enhanced multiphoton ionization (REMPI) through the d ^1Π_g state. A σ_u shape resonance near the ionization threshold leads to non‐Franck–Condon vibrational branching ratios and a substantial dependence of photoelectron angular distributions on the vibrational state of the X ^2Π_g ion. Significant differences exist between our one‐electron predictions and experiment. These are mainly attributed to electronic autoionization of repulsive ^1∑^−_u , ^1∑^+_u , and ^1Δ_u states associated with the 1π^3_u 1π^3_g configuration. A proposed singlet "K" ^1Π_u Rydberg state converging to the A ^2Π_u ion probably also contributes to autoionization in the d ^1Π_g state spectrum. We also show that autoionizing H and J ^3Π_u Rydberg states of O_2 converging to the a ^4Π_u and A ^2Π_u ionic thresholds, respectively, may play a previously unsuspected role in the C ^3Π_g state one‐color REMPI spectra. We discuss multiplet‐specific (spin‐dependent) effects via comparison of these results with recent experimental and theoretical studies of O_2 C ^3Π_g photoionization.
Additional Information
© 1990 American Institute of Physics. (Received 9 August 1989; accepted 26 January 1990) The authors are grateful to P. J. Miller and W. A. Chupka for permission to use unpublished REMPI photoelectron spectra for the O_2 d ^1Π_g state in this work. This work was supported by grants from the National Science Foundation (CHE-8521391), Air Force Office of Scientific Research (Contract No. 87-0039), and the Office of Health and Environmental Research of the U.S. Department of Energy (DE-FG03-87ER60513). We also acknowledge use of resources of the San Diego SuperComputer Center, which is supported by the National Science Foundation. One of us (M. B.) would like to acknowledge support from a Department of Education Fellowship.Attached Files
Published - 1.458511.pdf
Files
| Name | Size | Download all |
|---|---|---|
|
md5:ea0c9461e3fc0ae8b60e4d23240c1783
|
1.0 MB | Preview Download |
Additional details
- Alternative title
- Multiplet-specific shape resonance and autoionization effects in (2+1) resonance enhanced multiphoton ionization of O2 via the d 1Πg state
- Eprint ID
- 61642
- Resolver ID
- CaltechAUTHORS:20151028-114730778
- NSF
- CHE-8521391
- Air Force Office of Scientific Research (AFOSR)
- 87-0039
- Department of Energy (DOE)
- DE-FG03-87ER60513
- Department of Education Fellowship
- Created
-
2015-11-10Created from EPrint's datestamp field
- Updated
-
2021-11-10Created from EPrint's last_modified field
- Other Numbering System Name
- Caltech Arthur Amos Noyes Laboratory of Chemical Physics
- Other Numbering System Identifier
- 8015