Controlling Energetics in Multi-Redox Molecular Systems

Abstract

The electronic tunning of coordination complexes through ligand modification is fundamental for understanding properties and reactivity. Studies of proton-coupled electron transfer (PCET) in ruthenium amine/amido complexes show new features of the reactivity of the Ru-N-H bond with relevance to catalysis and energy conversion. The electronic influence of  back-bonding capabilities at bipyridine-type ligands in a family of ruthenium-amine complexes [1,2] affects redox potentials at the metal center and pKa?s of the NH?s encompassing several oxidation states. This allows accessibility of and potential inversion for the 2-electron process between d6-d4 configurations and tunability of BDFE for N-H bonds.These results underline the ability of the orbital interaction between Ru and N to modulate electronic states and its influence over redox, acid-base, spectroscopic, and reactivity properties.