Unraveling the mysteries of metastable O{sub 4}{sup {asterisk}}
- Chemical Sciences Division, Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
- Quantum Theory Project, University of Florida, Gainesville, Florida 32611 (United States)
A recent report from our laboratory described 1+1 resonant photoionization spectra of an energetic, metastable O{sub 4} species produced in a dc discharge [Bevsek {ital et al.}, Faraday Discuss. {bold 108}, 131 (1998)]. Although a definitive assignment of the spectra was lacking, the long-predicted covalent forms of O{sub 4}, either cyclic (D{sub 2d}) or {open_quotes}pinwheel{close_quotes} (D{sub 3h}), were adduced as possible candidates. We here present rotationally resolved photoionization spectra, photoelectron spectra, and {ital ab initio} calculations providing strong evidence for the identity of this species as a novel complex between a ground state O{sub 2} molecule and one in the c({sup 1}{Sigma}{sub u}{sup {minus}}) state, which is excited via an allowed transition to the 1({sup 1}{Pi}{sub g})valence state. The latter then couples to the d({sup 1}{Pi}{sub g}) Rydberg state, shifted in energy owing to the presence of the adjacent O{sub 2} molecule, from which it then ionizes. The results underscore the potential importance of the fully allowed but overlooked 1({sup 1}{Pi}{sub g}){l_arrow}c({sup 1}{Sigma}{sub u}{sup {minus}}) electronic transition in O{sub 2} in the near ultraviolet, and provide a simple interpretation of puzzling results in an earlier study of electron transfer to O{sub 4}{sup +} [H. Helm and C. W. Walter, J. Chem. Phys. {bold 98}, 5444 (1993)]. {copyright} {ital 1999 American Institute of Physics.}
- OSTI ID:
- 335569
- Journal Information:
- Journal of Chemical Physics, Vol. 110, Issue 13; Other Information: PBD: Apr 1999
- Country of Publication:
- United States
- Language:
- English
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