Kinetics of the Photolysis of Methyl Iodide and the Hydrogen Halides II. Photolysis of Methyl Iodide in the Presence of Iodine and the Hydrogen Halides

The photodissociation of methyl iodide by light of λ2537A has been utilized as a source of methyl radicals for a study of their subsequent reactions with iodine and the hydrogen halides. The observed rate of methane formation has been used to evaluate the ratio of rate constants for the following reactions: $$\begin{array}{c}{\mathrm{CH}}_3+\mathrm{HX}\to {\mathrm{CH}}_4+\mathrm{X}\\ {\mathrm{CH}}_3+{\mathrm{I}}_2\to {\mathrm{CH}}_3\mathrm{I}+\mathrm{I}\end{array}$$ where X represents Cl, Br or I. The reaction with hydrogen chloride has been found to be complicated by the unequal yield of methane and iodine, and possible explanations of this phenomenon have been considered.