A Parent Iron Amido Complex in Catalysis of Ammonia Oxidation.

Parent amido complexes are crucial intermediates in ammonia-based transformations. We report a well-defined ferric ammine system [Cp*Fe(1,2-PhPCHNH)(NH)] ([-NH]), which processes electrocatalytic ammonia oxidation to N and H at a mild potential. Through establishing elementary e/H conversions with the ferric ammine, a formal Fe(IV)-amido species, [-NH], together with its conjugated Lewis acid, [-NH], was isolated and structurally characterized for the first time. Mechanism studies indicated that further oxidation of [-NH] induces the reaction of the parent amido unit with NH. The formation of hydrazine is realized by the non-innocent nature of the phenylamido ligand that facilitates the concerted transfer of one proton and two electrons.