Photochemical and photophysical properties of self-assembling 5-(4-pyridyl)-10,15,20-triphenylporphinatozinc (Znpyp3) have been studied by steady-state and time-resolved absorption in addition to time-resolved fluorescence spectroscopy. Self-assembling oligomers (Znpyp 3)n (n = 3 at 0.1 mM) were synthetically generated and assigned to a zigzag chain oligomeric structure, where n is dependant on the concentration and temperature. The lifetimes of the singlet and triplet excited states of (Znpyp3)n depend on n and the axial ligation. The rate-constant of (Znpyp3)n for the intermolecular T-T annihilation process was smaller than that of monomeric porphyrins. In the photoinduced electron-transfer to fullerenes (C60 and C 70), it was revealed that the rate-constants and efficiencies for (Znpyp3)n were essentially the same as those of the monomer. In the back electron transfer, the rate-constants of oligomers were smaller than that of the monomeric porphyrin, which suggests hole-delocalization along the porphyrin chain.
- Laser photolysis