Tris(bipyridine)ruthenium(II)-photosensitized reduction of a CoIII–Schiff base complex in a network of gelatin hydrogel and in an aqueous gelatin solution
Abstract
The Ru(bpy)2+3 photosensitized reduction of a CoIII–Schiff base complex proceeds effectively in a network of gelatin hydrogel and in an aqueous gelatin solution under anaerobic conditions. In both systems, a reduced intermediate species of the CoIII complex coordinated to a gelatin molecule, which has an absorption maximum at 450 nm (R450), was initially generated. After irradiation had been stopped, R450 turned slowly to the diaqua CoII–Schiff base complex in the hydrogel system whereas it was oxidized gradually to the initial CoIII–Schiff base complex in an aqueous gelatin solution. It is suggested from the results obtained that the gelatin acts as the ligand for the CoIII complex, and both the electron donor and, probably, electron acceptor for the photosensitized reactions in both the systems.