Synthesis and fluorescence behavior of novel Ru(bpy)3–porphyrin conjugates

No emission of photoexcited Ru(bpy)3 was found in Fe and Mn porphyrin–Ru(bpy)3 conjugates. In the case of free-base and Zn porphyrin–Ru(bpy)3 conjugates, quenching of Ru(bpy)3 emission and the appearance of considerable free-base and Zn porphyrin emissions were found. The excitation spectra of these emissions revealed however that these emissions originate from the corresponding excitation of free-base and Zn porphyrin moieties. These observations suggest efficient intramolecular electron transfer from the photoexcited Ru(bpy)3 moiety to the free-base, Zn, Fe and Mn porphyrins.