Mechanism of reaction of Recoil Hydrogen in the Gas Phase

Journal Article · Sat Nov 01 04:00:00 EST 1958 · Journal of Physical Chemistry

DOI:https://doi.org/10.1021/j150569a004· OSTI ID:4291566

El-Sayed, Mostafa Amr; Estrup, Peder J.; Wolfgang, Richard

The interaction of high energy tritium (H/sup 3/), formed by nuclear recoil, with gaseous methane and ethane, has been investigated under a wide variety of conditions. In the case of methane, a number of labeled products, chiefiy HT and CH/sub 3/T, together with smaller amounts of higher tritium labeled hydrocarbons are formed. If a radical scavenger, such as I/sub 2/, is presert, the yield of CH/sub 3/T is little changed, but the amount of HT is halved and the higher hydrocarbons eliminated. These results are not consistent with present theories of the mechanism of the primary step of hot-atom reaction. An alternative hypothesis that reactions of gas phase hot ""atoms'' are really due to ions does not appear tenable in the case of recoil tritium. A mechanism involving a high energy one-step displacement reaction as the primary reaction of the hot atom is suggested. Some of the labeled products of this primary reaction reach thermal energies as radicals which will then undergo further secondary reaction. Unlike the primary hot reactions, these thermal secondary processes are sensitive to the addition of radical scavengers. Evidence for this mechanism is obtained from a consideration of the detailed product distributions and their changes when certain experimental conditions, such as radiation intensity, are varied. Particularty significant are the consequences of the addition of a large excess of He4 to moderate the hot atoms. A review of earlier data makes it appear probable that the primary hot replacement mechanism thus indicated for the gas phase reaction of recoil tritium is also operative in the condensed phase. The further extension of this mechanism to hot atom reactions in general is briefiy discussed.

• Research Organization: Yale Univ., New Haven
• Sponsoring Organization: USDOE
• NSA Number: NSA-13-002811
• OSTI ID: 4291566
• Journal Information: Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 11 Vol. 62; ISSN 0022-3654
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ACTIVATION
ATOMS
BIBLIOGRAPHY
CHEMICAL REACTIONS
DECONTAMINATION
DISTRIBUTION
EFFICIENCY
ENERGY LEVELS
ETHANE
FREE RADICALS
GASES
HELIUM
HYDROCARBONS
HYDROGEN
IODINE
IONS
LABELLED COMPOUNDS
LIQUIDS
MEASURED VALUES
METHANE
MOLECULES
NUCLEAR REACTIONS
RADIATION CHEMISTRY
RADIATION DOSES
RADIATION EFFECTS
REACTION KINETICS
RECOILS
REVIEW
TABLES
TRITIUM