| Abstract: | The synthesis of a number of ring-substituted phenyl isopropenyl ketones and their polymerization with styrene is reported. The ultraviolet absorption spectra of the polymers are analogous to those of ring-substituted acetophenones and valerophenones. The quantum yields of the Norrish type II photoreaction were estimated in 1,2-dichloroethane solution at 364 nm by automatic viscometry. These quantum yields are comparable to those of substituted butyrophenones and valerophenones, in that relatively high quantum yields were obtained for the unsubstituted and p-chloro-substituted compounds with low yields for p-amino and p-hydroxy compounds. The p-nitro-substituted compound gives no type II reaction, presumably because the excitation becomes localized on the nitro groups which photolyzes by a mechanism which does not involve chain scission. The implications of these studies on possible applications to photoimaging are discussed. |
