PHOTOINDUCED ELECTRON-TRANSFER REACTION OF (PHENYLAZO)TRIPHENYLMETHANE (PAT) - BEHAVIOR OF GENERATED TRITYL CATION

The decomposition mechanism of photoinduced electron transfer (PET) be tween electron deficient sensitizers and (phenylazo)triphenylmethane ( PAT) was investigated. In 9,10-dicyanoanthracene (DCA) sensitized reac tion, benzene, triphenylmethane, 3,3,3-triphenylpropionitrile, and [4- (diphenylmethyl)phenyl] acetonitrile were obtained, and the product di stribution was the same as for the direct photolysis and the thermolys is. In the case of 2,4,6-triphenylpyrylium tetra fluoroborate (TPP+) s ensitization, the product distribution was drastically changed and 9-p henylfluorene was found to be one of the main products. The results of the irradiation wavelength effects indicate that 9-phenylfluorene is produced by the photoreaction of a trityl cation which is generated by the decomposition of a radical cation of PAT. The results of the expe riments of laser flash photolysis suggest that the rate of back electr on transfer between a radical anion of the sensitizer and a trityl cat ion plays an important role in these reactions.