Azo N[DOUBLE BOND]N Bond Cleavage with a Redox-Active Vanadium Compound Involving Metal–Ligand Cooperativity


  • We thank the Air Force Office of Scientific Research for financial support. C.M. also acknowledges the Alexander von Humboldt Foundation for a Feodor Lynen postdoctoral fellowship. S.P.S. and Z.R.T. thank the Natural Sciences and Engineering Research Council of Canada and the US–UK Fulbright Commission and AstraZeneca for fellowships, respectively. We also thank Professor K. Howard (Swarthmore) for help with EPR data collection and the Max Planck Institute for Bioinorganic Chemistry (Mülheim) for computational resources.


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Coop mode: The reaction of azobenzene with a redox-active bis(imino)pyridine vanadium dinitrogen complex resulted in N[DOUBLE BOND]N bond cleavage and formation of the bis(imido) derivative (see picture). Similar reactivity was observed with O2 and S8 to yield the analogous terminal bis(oxides) and bis(sulfides), respectively. Studies of the electronic structure of the vanadium products show that bond cleavage involves reducing equivalents from the metal and the ligands.