Water oxidation catalyzed by a new tetracobalt-substituted polyoxometalate complex: [{Co4(μ-OH)(H2O)3}(Si2W19O70)]11-

A new polyoxometalate of earth adundant elements [{Co-4(mu-OH)(H2O)(3)}(Si2W19O70)](11-) has been synthesized, characterized and shown to be a water oxidation catalyst. The initial catalytic complex is unstable and slowly undergoes hydrolysis. The hydrolysis products have been isolated and characterized, and their catalytic water oxidation activity is assessed.