Hollow organosilica spheres as hosts: Photoinduced electron transfer between image and methylviologen

New organosilica hollow spheres containing the View the MathML sourceRu(bpy)32+ complex inside the walls have been prepared. This new material exhibits the typical phosphorescence of the photolumophore with a long emission lifetime, while laser flash photolysis measurements has allowed us the detection of photoejected electrons. The addition of MV2+ on the external surface neither quenches nor alters the transient optical spectrum on the submillisecond time scale. However, when an aqueous solution of MV2+ containing triethylamine is photolyzed in the presence of the ruthenium-containing spheres, the build up of a MVradical dot+ radical cation and eventually MV0 is observed. This proves that photoejected electrons initially located in the walls of the hollow spheres can be trapped at long time scale by an external quencher, the organosilica walls of the hollow spheres acting as electron relay.