Billiard-Ball Collisions in the Reactions of Hot Hydrogen Atoms. Isotope Effect on the Hydrogen Displacement in Methane

Journal Article · Sun Jan 01 04:00:00 EST 1961 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.1732201· OSTI ID:4803775

Cross, Jr, R J; Wolfgang, R

The nature of collisions leading to reactions of hydrogen atoms of high kinetic energy (in the form of recoil tritium) was investigated. Two extreme models were examined. One assumes very weak coupling by valence bonds in the molecule attacked, so that the reaction can be represented by a quasi-elastic atom-atom collision (billiard-ball model) and the other assumes strong valence bond coupling (epithermal model). Calculations on the billiard-ball (hard sphere) model of the reaction T* + CH₄ yields H + CH₃T leads to an estimate of its relative cross section as a function of energy. An isotope effect for reaction with CH₄ and with CD₄ is calculated and measured experimentally. Consideration of both the calculations and the experimental results indicate that the billiard-ball model is unimportant in the reactions of gas phase hot hydrogen (as recoil tritium), and that reactions occur nearly exclusively at less than 1020 ev of kinetic energy by mechanisms involving strong bond coupling. The possible importance of the billiard-ball model in the reactions of other hot atoms is briefly discussed.

• Research Organization: Yale Univ., New Haven
• Sponsoring Organization: USDOE
• NSA Number: NSA-16-009934
• OSTI ID: 4803775
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 6 Vol. 35; ISSN JCPSA6; ISSN 0021-9606
• Publisher: American Institute of Physics (AIP)
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ATOMS
COLLISIONS
CONFIGURATION
ENERGY RANGE
HYDROGEN
INTERACTIONS
ISOTOPE EFFECTS
METHANE
NUCLEAR REACTIONS
REACTION KINETICS
RECOILS
TRITIUM