Transition state spectroscopy of the OH + H{sub 2} {yields} H{sub 2}O + H reaction via photodetachment of H{sub 3}O{sup -} and D{sub 3}O{sup -}

Journal Article · Thu Sep 14 04:00:00 EDT 1995 · Journal of Physical Chemistry

DOI:https://doi.org/10.1021/j100037a009· OSTI ID:111235

Beer, E de; Kim, E H; Neumark, D M ^[1]; Gunion, R F; Lineberger, W C ^[2]

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1. Univ. of California, Berkeley, CA (United States)
2. Univ. of Colorado, Boulder, CO (United States)

The transition state region of the reaction OH + H{sub 2} {yields} H{sub 2}O + H is investigated by photoelectron spectroscopy of the H{sub 3}O{sup -} and D{sub 3}O{sup -} anions. The peaks observed in the spectra are from a combination of vibrational progressions and overlapping anion {yields} neutral electronic transitions. The photoelectron angular distributions indicate that two processes contribute to the spectra; these are assigned to photodetachment from the H{sup -}(H{sub 2}O) and OH (H{sub 2}) forms of the anion. A comparison of experiments performed in two different laboratories shows that the two forms of the ion readily interconvert and that the relative populations are determined solely by the temperature of the ions. To interpret the spectra, a two-dimensional ab initio potential energy surface for the anion was constructed, wave functions for the first few vibrational levels were determined, and the photoelectron spectra were simulated using the Walch-Dunning-Schatz-Elgersma surface for the OH + H{sub 2} reaction. A comparison of the experimental and simulated spectra showed that photodetachment from the {nu} = 0 level of the anion, which is localized in the H{sup -}(H{sub 2}O) well, primarily probes the H + H{sub 2}O exit valley of the neutral surface. The {nu} = 2 level of the anion is the first with significant amplitude in the OH{sup -}(H{sub 2}) well, and photodetachment from this level probes the OH + H{sub 2} transition state region. 36 refs., 13 figs., 2 tabs.

• Sponsoring Organization: USDOE
• OSTI ID: 111235
• Journal Information: Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 37 Vol. 99; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
55 BIOLOGY AND MEDICINE
BASIC STUDIES
ANGULAR DISTRIBUTION
ANIONS
BINDING ENERGY
HYDROGEN
MOLECULAR BIOLOGY
NUMERICAL DATA
PHOTOCHEMICAL REACTIONS
PHOTOELECTRON SPECTROSCOPY
POTENTIAL ENERGY
SIMULATION
WATER