N. Miyagawa et al., PHOTOINDUCED ELECTRON-TRANSFER REACTION OF (PHENYLAZO)TRIPHENYLMETHANE (PAT) - BEHAVIOR OF GENERATED TRITYL CATION, Bulletin of the Chemical Society of Japan, 69(11), 1996, pp. 3325-3329
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.