Light-driven water oxidation with a molecular tetra-cobalt(III) cubane cluster

Photoinduced water oxidation to molecular oxygen takes place in systems made of [Ru(bpy)(3)](2+) (bpy 2,2'-bipyridine) as the photosensitizer, [Co4O4(O2CMe)(4)(py)(4)] (py pyridine) as the molecular catalyst and Na2S2O8 as the sacrificial electron acceptor. The photochemical quantum yield of the process reaches the outstanding value of 30% and depends on pH and catalyst concentration. Transient absorption spectroscopy experiments aimed to clarify the first events of the photocatalytic process are also reported.