Photoinduced water oxidation sensitized by a tetranuclear Ru(II) dendrimer

A multimetallic ruthenium(II) dendrimer is used for the first time to photosensitize dioxygen production from water by IrO2 nanoparticles; the system is more efficient than an analogous system based on the more commonly used [Ru(bpy)(3)](2+)-type photosensitizers, in particular for the ability of the dendrimer to take advantage of the red portion of the solar spectrum.