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-Ph 2 PC 6 H 4 NH)(NH 3 )] + ([ 1 -NH 3 ] + ), which processes electrocatalytic ammonia oxidation to N 2 and H 2 at a mild potential. Through establishing elementary e - /H + conversions with the ferric ammine, a formal Fe(IV)-amido species, [ 1 -NH 2 ] + , together with its conjugated Lewis acid, [ 1 -NH 3 ] 2 + , was isolated and structurally characterized for the first time. Mechanism studies indicated that further oxidation of [ 1 -NH 2 ] + induces the reaction of the parent amido unit with NH 3 . 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.