Proton-Induced Dynamic Equilibrium between Cyclometalated Ruthenium rNHC (Remote N-Heterocyclic Carbene) Tautomers with an NAD+/NADH Function

Abstract

Cyclometalated ruthenium(II) complexes having acridine moieties have been synthesized and characterized by spectroscopic methods. Protonation of the acridine nitrogen of the ruthenium(II) complexes not only causes dynamic equilibrium with remote N-heterocyclic carbene Ru═C complexes but also generates the NAD(+)/NADH redox function driven by a proton-coupled two-electron transfer accompanying a reversible C-H bond formation in the pyridinium ring.