Photoinduced electron transfer from triphenylmethyl anion or triphenylsilyl anion to p-terphenyl

Abstract

The steady illumination of triphenylsilyl anion and p-terphenyl (p-TP) in tetrahydrofuran yielded the radical anion of p-terphenyl (p-TP^˙–), which persisted after cutting off the light. When the triphenylmethyl anion was used, p-TP^˙– was not observed with the steady illumination; the finding that p-TP^˙– observed transiently by flash photolysis decayed at a diffusion-controlled rate suggests that the stable triphenylmethyl radical, produced after the donation of an electron to p-TP, accepts an electron from p-TP^˙–. On the other hand, since the triphenylsilyl radical is able to produce the disilane whose electron-acceptor ability is less than that of p-TP, back electron transfer from p-TP^˙– to the disilane does not occur and thus p-TP^˙– persists.