Adaptive water oxidation catalysis on a carboxylate-sulfonate ligand with low onset potential.

A water oxidation catalyst Ru-bcs (bcs = 2,2'-bipyridine-6'-carboxylate-6-sulfonate) with a hybrid ligand was reported. Ru-bcs utilizes the electron-donating properties of carboxylate ligands and the on-demand coordination feature of sulfonate ligands to enable a low onset potential of 1.21 V vs. NHE and a high TOF over 1000 s -1 at pH 7. The adaptive chemistry uncovered in this work provides new perspectives for developing molecular catalysts with high efficiency under low driving forces.