The catalytic water oxidation activity of mononuclear ruthenium complexes comprising a pyridine-functionalized abnormal triazolylidene ligand can be adjusted by modification of the triazolylidene substituents, which is readily achieved through click-type cycloaddition chemistry, affording some of the most active ruthenium catalysts known thus far for water oxidation (TONs > 400, TOFs close to 7000 h-1).
![Tunable single-site ruthenium catalysts for efficient water oxidation](https://www.iciq.org/wp-content/uploads/2014/03/Tunable-single-site-ruthenium_8058.gif)