Abstract
High energy tritium atoms with kinetic energies of 1.1, 1.6, 1.9, 2.8, 4.5 and 6.0 e.v. were formed by the photodissociation of TBr with radiation of variation wavelengths. In the last two cases, the technique of vacuum U.V. photolysis was employed in their formation. These high energy tritium atoms were allowed to react with the fluoromethanes CH₂F₂, CHF₃ and CF₄. Both tritium abstraction and substitution reactions were observed. The yields of the T*-for-H and T*-for-F substitution products from each system at each energy wee expressed relative to HT, the abstraction product. In both CH₂F₂ and CHF₃ systems, the above relative yields were zero at 1.9 e.v. or below and showed an increasing trend at higher energies. The T*-for-H substitution was always more favorable than its T*-for-F counterpart. The fact that high HT yields have been observed in all these systems gives support to the view that abstraction is a relatively low energy process. The threshold energies of hydrogen abstraction from fluoromethanes can be predicted to be about 0.35 e.v. or slightly higher. Using the extrapolation method, the threshold energy for the T*-for-H substitution in CHF₃ was determined to be 2.2 ± 0.2 e.v. Although, accurate values can not be determined for T*-for-F substitution in CHF₃ and for both kinds of substitution in CH₂F₂, their threshold energies lie between 1.9 and 2.8 e.v. Since CTF₃ was not detected from CF₄ systems even with 6.0 e.v. tritium atoms, the T*-for-F substitution has a very high threshold.
Min, Byung Kwon (1971). Reactions of photochemically produced high energy tritium atoms with fluoromethanes. Doctoral dissertation, Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -172503.