Wavelength effect in the photolysis of halogenated ketones

Abstract

An extended study of the wavelength effect in the photolysis of halogenated ketones has been carried out. The variation in product yield has been related to the effect of temperature rise and the addition of quenching gases. The effect is explained in terms of the competition of two primary photodissociations with an energy difference of 4 kcal mol^–1. The efficient quenching by hydrocarbons is shown to be due to chemical reactions of the excited ketone molecule with the substrate. The products of these reactions which are substituted isobutyl alcohols and ethers have been isolated. The results of kinetic studies are correlated with electron impact determinations of bond dissociation energies.