A series of porphyrin-oxadiazole dyads were synthesized from 5-(p-aminophenyl)-10,15,20- triphenylporphyrin and 2-phenyl-5-(p-aminophenyl)-1,3,4-oxadiazole and characterized by ¹H NMR, ESI-MS, IR and UV-Vis. The experiment results showed that fluorescence of porphyrin was quenched when porphyrin was mixed with oxadiazole, indicating the occurrence of photoinduced electron transfer from a porphyrin molecule to an oxadiazole molecule. However, intramolecular photoinduced energy transfer occurred in the porphyrin-oxadiazole dyads from excited oxadiazole moiety to porphyrin moiety, leading to the fluorescence quenching of oxadiazole moiety and the fluorescence enhancement of the porphyrin moiety. But no electron transfer was found from the excited porphyrin moiety to the oxadiazole moiety. Moreover, cyclic voltammetric studies of the dyads 5a, 3b and 4b further indicated that electron transfer from the oxadiazole moiety to the porphyrin moiety was possible. Hence the porphyrin-oxadiazole dyads might be used as PS II model compounds to simulating the electron transfer from an electron donor side to chlorophyll.

Key words: porphyrin, oxadiazole, cyanuric chloride, synthesis, energy transfer, electron transfer