Electrochemical ammonia oxidation catalyzed by ruthenium complexes: investigation of substituent effect of axial pyridine ligands

We have examined catalytic ammonia oxidation using ruthenium complexes bearing 2,2′-bipyridine-6,6′-dicarboxylate ligand and axial 3- and 4-substituted pyridine ligands under electrochemical conditions to study the substituent effect of the axial pyridine ligands. Ruthenium complex bearing 3,4-dibromopyridine ligands shows the highest catalytic activity to produce up to 145 equivalents of dinitrogen based on the catalyst.