Infrared spectroscopy and time-resolved dynamics of the ortho-H{sub 2}{endash}OH entrance channel complex

Journal Article · Tue Sep 01 04:00:00 EDT 1998 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.476941· OSTI ID:641514

Anderson, D T; Schwartz, R L; Todd, M W; Lester, M I ^[1]

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

The rotationally resolved infrared spectrum of the prereactive o-H{sub 2}{endash}OH complex in its ground electronic state is obtained in the OH overtone region at {approximately}1.4 {mu}m using an IR-UV double resonance fluorescence enhancement technique. The pure OH overtone band of o-H{sub 2}{endash}OH is observed as well as approximately 20 additional rovibrational transitions extending out to the OH (Xthinsp{sup 2}{Pi},v=2)+o-H{sub 2}(Xthinsp{sup 1}{Sigma}{sub g}{sup +}) dissociation limit. These transitions are assigned as combination bands involving the simultaneous excitation of the OH vibrational overtone and intermolecular bending (internal rotor) states. The assignment of the experimental spectrum is aided by a detailed comparison with the bound states computed for the {ital ab initio} potential of Clary, Werner, and co-workers [Mol. Phys. {bold 83}, 405 (1994)]. The infrared spectroscopy results also verify the topology of this {ital ab initio} potential in the entrance channel to the OH+H{sub 2} hydrogen abstraction reaction. Direct time-resolved experiments indicate that the lifetime of the vibrationally activated o-H{sub 2}{endash}OH complex in the ground intermolecular state is 115(26) ns. The initial excitation is found to stay localized in the OH intramolecular stretching mode for a long period of time prior to vibrational predissociation or chemical reaction. {copyright} {ital 1998 American Institute of Physics.}

• OSTI ID: 641514
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 9 Vol. 109; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
CHEMICAL REACTIONS
GROUND STATES
HYDROGEN
HYDROXYL RADICALS
INFRARED SPECTRA
TIME RESOLUTION