A hydrogen-bonded complex between the hydroxyl radical and acetylene has been stabilized in the reactant channel well leading to the addition reaction and characterized by infrared action spectroscopy in the OH overtone region. Analysis of the rotational band structure associated with the a-type transition observed at 6885.53(1) cm−1 (origin) reveals a T-shaped structure with a 3.327(5) Å separation between the centers of mass of the monomer constituents. The OH (v = 1) product states populated following vibrational predissociation show that dissociation proceeds by two mechanisms: intramolecular vibrational to rotational energy transfer and intermolecular vibrational energy transfer. The highest observed OH product state establishes an upper limit of 956 cm−1 for the stability of the π-type hydrogen-bonded complex. The experimental results are in good accord with the intermolecular distance and well depth at the T-shaped minimum energy configuration obtained from complementary ab initio calculations, which were carried out at the restricted coupled cluster singles, doubles, noniterative triples level of theory with extrapolation to the complete basis set limit.
Journal of Chemical Physics
AMERICAN INSTITUTE OF PHYSICS
Digital Object Identifier (DOI)
J. B. Davey, M. E. Greenslade, M. D. Marshall, M. I. Lester, M. D. Wheeler, “Infrared spectrum and stability of a π-type hydrogen-bonded complex between the OH and C2H2 reactants,” J. Chem. Phys. 121, 3009 (2004).
© 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. 121, 3009 (2004)