Isolation and Structure of the First Azo Anion Radical Complexes of Ruthenium

The anaerobic reaction of 1 (X = H, Cl) with 2 in heptane affords the green paramagnetic (S = 1/2) and EPR-active (g = 2.00) title complexes 3a (X = H) and 3b (X = Cl), which furnish the corresponding nonradical diamagnetic salts 3a+ PF6- and 3b+ PF6- upon oxidation in solution. In contrast, the reaction of 2 with N-(p-tolyl)pyridine-2-aldimine (pal) affords [Ru(pal)(H)(Cl)(CO)(PPh3)]. The X-ray structures of 3a and 3b+ have been determined.