Study on the intermediate of photooxidative degradation of phenylenevinylene oligomers

The results of the investigation on photooxidative degradation of five phen ylenevinylene oligomers are as follows. The sequence of the photodegradatio n rate in self-sensitized reaction is the same as that in the biacetyl-sens itized reaction and the rate of photooxidative degradation increases upon t he incorporation of electron-donating groups and decreases upon the incorpo ration of electron-accepting groups on the oligomers. The self-sensitized r eaction rate of oligomers increases as the solvent changing from benzene to deuterated benzene and decreases with the addition of the singlet oxygen ( O-1(2)) scavenger, O-1(2) is shown to be the main reactive intermediate in self-sensitized photolysis of phenylenevinylene oligomers, which was direct ly confirmed by ESR spin trapping experiments.