Redox-Active-Ligand-Mediated Formation of an Acyclic Trinuclear Ruthenium Complex with Bridging Nitrido Ligands

Coordination of a redox-active pyridine aminophenol ligand to Ru-II followed by aerobic oxidation generates two diamagnetic Ru-III species [1a (cis) and 1b (trans)] with ligand-centered radicals. The reaction of 1a/1b with excess NaN3 under inert atmosphere resulted in the formation of a rare bis(nitrido)-bridged trinuclear ruthenium complex with two nonlinear asymmetrical Ru-N-Ru fragments. The spontaneous reduction of the ligand centered radical in the parent 1a/1b supports the oxidation of a nitride (N-3(-)) to half an equivalent of N-2. The trinuclear omplex is reactive toward TEMPO-H, tin hydrides, thiols, and dihydrogen.