Photoinduced electron transfer and enhanced fluorescence of C60 pearl-necklace polymers

Photoinduced electron transfer (PET) and enhancement of fluorescence were observed simultaneously for a series of donor–acceptor-type C60 pearl-necklace polymers, contradicting the conventional notion that the formation of charge-separated state derived from electron transfer (ET) causes the quenching of fluorescence. The quantum yield Φf of the present polymers was one to two orders of magnitude larger than that of the pristine C60. On the other hand, light-induced electron spin resonance (LESR) signals, exhibiting signatures of both the aromatic diamine component cation and the C60 anion, implied the formation of an ion–radical pair caused by the PET.