Abstract

Fluorescence-dip infrared spectroscopy, an UV-IR double-resonance technique, is employed to characterize the line positions, linewidths, and corresponding lifetimes of highly predissociative rovibrational levels of the excited A  electronic state of the OH radical. Various lines of the 4←2 overtone transition in the excited A  state are observed, from which the rotational, centrifugal distortion, and spin-rotation constants for the A  (v = 4) state are determined, along with the vibrational frequency for the overtone transition. Homogeneous linewidths of 0.23–0.31 cm−1 full width at half maximum are extracted from the line profiles, demonstrating that the N = 0 to 7 rotational levels of the OH A  (v = 4) state undergo rapid predissociation with lifetimes of ⩽ 23 ps. The experimental linewidths are in near quantitative agreement with first-principles theoretical predictions.

Publication Date

6-2005

Journal Title

Journal of Chemical Physics

Publisher

AMERICAN INSTITUTE OF PHYSICS

Digital Object Identifier (DOI)

10.1063/1.1937387

Document Type

Article

Rights

© 2005 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. J. Chem. Phys. 122, 244313 (2005)

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