Water Oxidation Catalyzed by a Dinuclear Cobalt–Polypyridine Complex

Abstract The dinuclear Co complex [(TPA)Co(μ‐OH)(μ‐O 2 )Co(TPA)](ClO 4 ) 3 ( 1 , TPA=tris(2‐pyridylmethyl)amine) catalyzes the oxidation of water. In the presence of [Ru(bpy) 3 ] 2+ and S 2 O 8 2− , photoinduced oxygen evolution can be observed with a turnover frequency (TOF) of 1.4±0.1 mol(O 2 ) mol( 1 ) −1 s −1 and a maximal turnover number (TON) of 58±5 mol(O 2 ) mol( 1 ) −1 . The complex is shown to act as a molecular and homogeneous catalyst and a mechanism is proposed based on the combination of EPR data and light‐driven O 2 evolution kinetics.