A functionalized, ethynyl-decorated, tetracobalt(III) cubane molecular catalyst for photoinduced water oxidation.

A new tetracobalt(III) cubane 1, carrying functionalized peripheral ethynyl groups, was prepared. Cubane 1 catalyses photoinduced water oxidation, indicating that the ethynyl groups do not negatively affect the catalytic properties of the Co cubane assembly. In contrast, the quantum yield for water oxidation (0.36) is significantly increased with respect to the prototype, simplest species.