Specific Electron Transfer Mechanism from the Photoexcited Tetrasulfonated Zn(II)-Tetraphenylporphyrin to Methylviologen via Self-Assembled Ionic Complex

摘要

Electron transfer from photoexcited tetrasulfonated Zn(II)-tetra-phenylporphyrin (ZnTSTPP) to methyviologen (MV~(2+)) was studied. From the investigation of relative fluorescence intensity and emission lifetime against the MV~(2+) concentration, it was concluded that the electron transfer takes place by a static mechanism. Based on the analysis of the quenching behavior, it was concluded that the static reaction did not follow an ordinary Perrin model, but interaction of the donor (photoexcited Zn-TSTPP) and the acceptor (MV~(2+)) molecules, ionic interaction in the present case, is responsible. The analysis of the quenching gave the equilibrium constant for the interaction to be K = 6.5 X 10~4 M~(-1). A two-dimensional selfassembled macromolecular ionic complex between ZnTSTPP and MV~(2+) is proposed.