State-to-state measurements of internal rotational predissociation in OH--Ar ([ital A] [sup 2][Sigma][sup +])

Journal Article · Mon Aug 15 04:00:00 EDT 1994 · Journal of Chemical Physics; (United States)

DOI:https://doi.org/10.1063/1.467604· OSTI ID:7171633

Giancarlo, L C; Randall, R W; Choi, S E; Lester, M I ^[1]

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1. Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323 (United States)

Internal rotational predissociative levels of OH--Ar ([ital A] [sup 2][Sigma][sup +]) have been identified lying up to 350 cm[sup [minus]1] above the OH [ital A] [sup 2][Sigma][sup +] ([ital v]=0, 1)+Ar dissociation limit. The predissociative level energies, lifetimes, and OH [ital A] [sup 2][Sigma][sup +] rotational product distributions have been measured. Complexes prepared in many of these predissociative levels are long lived with lifetimes [ge]50 ps. A novel variation of stimulated emission pumping has enabled quantitative OH [ital A] [sup 2][Sigma][sup +] rotational distributions to be obtained following OH--Ar predissociation. The OH product distributions are highly selective. The highest energetically available channel is always populated, yet in many cases, low rotational levels are conspicuously absent. The OH--Ar predissociative levels have been assigned nearly good quantum numbers based on a rotational contour analysis of the predissociative features and/or the OH [ital A] [sup 2][Sigma][sup +] rotational product distributions. A two-step mechanism involving Coriolis coupling and the potential anisotropy has been proposed to describe the predissociation process. A comparison between the experimentally measured and theoretically calculated observables provides a guide for further refinements of the OH [ital A] [sup 2][Sigma][sup +]+Ar potential energy surface.

• OSTI ID: 7171633
• Journal Information: Journal of Chemical Physics; (United States), Journal Name: Journal of Chemical Physics; (United States) Vol. 101:4; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

664200* -- Spectra of Atoms & Molecules & their Interactions with Photons-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
ARGON COMPLEXES
COMPLEXES
CORIOLIS FORCE
DISSOCIATION
ENERGY
ENERGY LEVELS
EXCITED STATES
HYDROXYL RADICALS
POTENTIAL ENERGY
PREDISSOCIATION
QUANTUM NUMBERS
RADICALS
ROTATIONAL STATES