Infrared spectroscopy of vibrationally excited HONO sub 2 : Shedding light on the dark states of intramolecular vibrational energy redistribution

Journal Article · Fri Feb 15 04:00:00 EST 1991 · Journal of Chemical Physics; (USA)

DOI:https://doi.org/10.1063/1.459866· OSTI ID:5959454

Fleming, P R; Li, M; Rizzo, T R ^[1]

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1. Department of Chemistry, University of Rochester, Rochester, New York 14627 (US)

Infrared predissociation spectroscopy of nitric acid subsequent to vibrational overtone excitation reveals vibrational state mixing of the highly excited levels and probes the character of the coupled dark states. A visible dye laser excites the 4{l arrow}0 or 5{l arrow}0 OH stretch transition and an optical parametric oscillator promotes the molecules above the dissociation threshold by a {Delta}{ital v}{sub OH}=1 transition from the excited level. Scanning the optical parametric oscillator frequency while monitoring the predissociation products via laser-induced florescence produces an infrared spectrum of the excited molecules. Although the 4{nu}{sub OH} vibrational overtone band consists of a single clean rotational contour that falls directly on a Birge--Sponer plot, the infrared transitions from this level indicate that the zeroth-order bright state is extensively mixed. On the average, the zeroth-order bright state is only a minor component of the eigenstates at this energy. The largest collective contribution is from zeroth-order states that have zero quanta of OH stretch.

• OSTI ID: 5959454
• Journal Information: Journal of Chemical Physics; (USA), Journal Name: Journal of Chemical Physics; (USA) Vol. 94:4; ISSN JCPSA; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
DISSOCIATION
ENERGY LEVELS
ENERGY TRANSFER
EXCITED STATES
HYDROGEN COMPOUNDS
INFRARED SPECTRA
INORGANIC ACIDS
NITRIC ACID
PREDISSOCIATION
SPECTRA
VIBRATIONAL STATES