Barrier height dependence of dynamics in the collinear HF(v) + H and HF(v) + D systems

Journal Article · Thu Nov 17 04:00:00 EST 1988 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100334a025· OSTI ID:6188579

Kaye, J A; Kuppermann, A; Dwyer, J P

Collinear coupled-channel quantum mechanical calculations have been performed on the HF + H and HF + D systems on potential energy surfaces with barriers to reaction of 1.5, 5, 10, 20, 30, and 40 kcal/mol. Calculations on these systems for the surface with the highest barrier as well as another low-barrier surface have been reported previously. The authors have examined the differences in the dynamics on the different surfaces, emphasizing the rate and mechanism of vibrational deactivation of HF in H + FH(..nu..) collisions and the influence of reagent vibrational excitation or reaction probabilities and product-state distributions in the D + FH(..nu..) reaction. The rate of vibrational deactivation decreases as the barrier height is increased for low-barrier-height surfaces but becomes relatively insensitive to barrier height at higher barrier heights at the temperatures studied. On the lower barrier surfaces vibrational deactivation occurs mainly in multiquantum reactive transitions, while for higher barrier surfaces it occurs in single-quantum nonreactive transitions. In the D + FH(..nu..) reaction, reagent vibrational excitation reduces the translational energy threshold by an amount smaller than the vibrational quantum and can lead to different product-state distributions depending on the potential energy surface. Quantum mechanical resonances observed on the lower-barrier surfaces can be understood by reference to vibrationally adiabatic correlation diagrams.

• Research Organization: California Institute of Technology, Pasadena (USA)
• OSTI ID: 6188579
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 92:23; ISSN JPCHA
• Country of Publication: United States
• Language: English

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
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54 ENVIRONMENTAL SCIENCES
CHEMICAL REACTIONS
DATA
DEUTERIUM
DYNAMICS
ELEMENTS
ENERGY LEVELS
EXCITED STATES
HYDROFLUORIC ACID
HYDROGEN
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
INFORMATION
INORGANIC ACIDS
ISOTOPES
LIGHT NUCLEI
MECHANICS
NONMETALS
NUCLEI
NUMERICAL DATA
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POTENTIALS
QUANTUM MECHANICS
RYDBERG STATES
STABLE ISOTOPES
THEORETICAL DATA
VIBRATIONAL STATES