PHOTOINDUCED ELECTRON-TRANSFER AND DYNAMIC BEHAVIOR OF CHARGE-SEPARATED STATE NONLINEAR-OPTICAL PROCESS IN A SELF-ASSEMBLED PORPHYRIN SUPRAMOLECULAR SYSTEM

The spectroscopic properties of a supramolecular system consisting of two oppositely charged porphyrin monomers, zinc tetra(4-sulfonoatophen yl)porphyrin and zinc tetra(N-methylpyridyl)porphyrin were studied by absorption and fluorescence spectroscopy. The stoichiometry of the sel f-assembled porphyrins were determined by a fluorimetric titration met hod showing the formation of the 1:1 heterodimer, Photoinduced electro n transfer and charge separation in the supramolecular system have bee n studied by time resolved forward degenerate-four-wave-mixing (DFWM) geometry. The results indicated the formation of the charge-separated state within 30 ps and the recombination time is about 340 ps. Light-i nduced enhancement of third-order nonlinear optical (NLO) susceptibili ty was observed.