Mononuclear Ruthenium–Water Oxidation Catalysts: Discerning between Electronic and Hydrogen-Bonding Effects

New mononuculear complexes of the general formula [Ru­(trpy)­(<i>n</i>,<i>n</i>′-F₂-bpy)­X]^<i>m</i>+ [<i>n</i> = <i>n</i>′ = 5, X = Cl (<b>3⁺</b>) and H₂O (<b>5²⁺</b>); <i>n</i> = <i>n</i>′ = 6, X = Cl (<b>4⁺</b>) and H₂O (<b>6²⁺</b>); trpy is 2,2′:6′:2″-terpyridine] have been prepared and thoroughly characterized. The 5,5′- and 6,6′-F₂-bpy ligands allow one to exert a remote electronic perturbation to the ruthenium metal center, which affects the combination of species involved in the catalytic cycle. Additionally, 6,6′-F₂-bpy also allows through-space interaction with the Ru–O moiety of the complex via hydrogen interaction, which also affects the stability of the different species involved in the catalytic cycle. The combination of both effects has a strong impact on the kinetics of the catalytic process, as observed through manometric monitoring