Modification of soluble polyphenylene by Friedel–Crafts reactions:: Introduction of benzyl and toluoyl groups to the polyphenylene and effects of the introduced group on optical properties of the polymer

Introduction of benzyl and toluoyl groups to a soluble p-phenylene/m-phenylene copolymer, PP, was carried out by Friedel–Crafts reactions using benzyl chloride and toluoyl chloride. Degrees of the introduction of the benzyl and toluoyl group per the phenylene unit of PP were estimated at 8.5 and 16.3%, respectively, from 1H NMR data. Original PP and the polymer with the benzyl group showed a strong photoluminescence with a quantum yield higher than 60% in chloroform. Introduction of the toluoyl group strongly affected the light emitting behavior of the polymer and caused a red shift of the emitted light.