RECOIL TRITIUM REACTIONS WITH ORGANIC MOLECULES IN THE GAS PHASE
Recoil tritium produced by a nuclear process was shown to substitute for hydrogen in organic compounds in the solid liquid and gas phases. The complexities of the reactions as observcd in the condenscd phases pointed out the need for thorough examination of the reactions in the experimentally less complex gas phase. The systems chosen were some simple organic molecules. Experiments were designed to determine effects of molecule structure and reactivity and bond types. The molecules examined were the light hydrocarbons C/ sub 1/-C/sub 4/, CH/sub 2/D/sub 2/, mixtures of H/sub 2/ and D/sub 2/, CH/sub 4 / and C/sub 4/, dimethyl ether, ethylene oxide, and acetone. It was observed that recoil tritium, formed in these systems by the nuclear reaction He/sup 3/(n,p)T, reacts with each of these molecules to give HT, labeled parent and labeled fragment molecules which are dependent on the nature of the parent molecule. The fragments from different molecules are similar and can be described as due to simple, usually one step, reactions with the parent where the reactions are the displacement of some group R by the tritium. Few products larger than parent are formed in these systems; all of these are removed by free radical scavengers. Recoil tritium exchange with thermal D atoms does not occur, as with methane and cyclopropane. Exchange can take place into structurally strained cyclopropane and ethylene oxide without isomerization. These two observations demonstrate that the reactions while requiring high kinetic energy to proceed, take place more rapidly than the time necessary for the energy of the tritium to become equilibrated throughout the molecule. The ratio of the formation of HT to DT in mixtures of H/sub 2/ and D/sub 2/ is favored by a factor of from 1.5to 1.7 to 1. In CH/sub 4/D/sub 2/ this ratio is in the range of 1.3 to 1.4 to 1; and in CH/sub 4/-CD/sub 4/ mixtures the ratio is about 1.25 to 1. The recoil reactions are explained in terms of the structure and reactivity of the molecules. Minor products are explained in terms of the radiation decomposition products and their known thermal reactions. The effects of pressure, added gases, irradiation length and irradiation flux were studied. Pressure influences the rate of stabilization versus decomposition of labeled products, particularly the parent molecule. Added scavengers remove thermal reaction products. It is possible to describe the change in the relative amounts of some of the products with length of irradiation by their appearance or disappearance according to known thermal reactions.
- Research Organization:
- Univ. of Kansas, Lawrence
- NSA Number:
- NSA-16-022098
- OSTI ID:
- 4815114
- Journal Information:
- Dissertation Abstr., Vol. Vol: 22; Other Information: Orig. Receipt Date: 31-DEC-62
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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