Photochemistry of Allyl Chloride in Liquid and Solid State

Abstract

AbstractThe photolysis at 2537 Å of liquid allyl chloride at 27°C and of solid allyl chloride at 77°K has been studied. The gaseous hydrocarbon products from the liquid photolysis were allene and propene in nearly equivalent amounts. The products from the solid photolysis were allene, propene, and cyclopropane; the yield of C3H6 hydrocarbons averaged 1.7 that of allene, while the average yield of propene alone was 1.3 that of allene. By the use of aqueous acetone as an actinometer, the quantum yield of C3 hydrocarbons in the liquid was found to be about 0.01. The primary process proposed is a breaking of the carbon‐chlorine bond to give allyl radical. A parallel primary process may be the formation of cyclopropyl radical. For the liquid the only secondary process needed to account for the products is the disproportionation of allyl radicals to give allene and propene. For the solid, in addition to disproportionation, abstraction of hydrogen atoms from allyl chloride is postulated.