IODINATION. PART IV. STUDIES ON THE PHOTOIODINATION OF DIFFERENT UNSATURATED ORGANIC COMPOUNDS IN LIGHT OF DIFFERENT FREQUENCIES IN NON-POLAR SOLVENTS.

Photochemical iodination of phenylacetylene, dicyclopentadiene, dimethylace- tylene dicarboxylate, β-amylene and phenylpropiolic acid in 546, 436 and 366μμ in solutions of Cl₄ has been described. The reaction is unimolecular with respect to iodine. The rate of reaction has a small temperature coefficient The quantum efficiency of the feaction has been worked out to be high in the case of phenylacetylene and dicyclopenta­diene but small in other cases.