Facile hydrogen atom transfer to iron(III) imido radical complexes supported by a dianionic pentadentate ligand

A dianionic tetrapodal pentadentate diborate ligand is introduced. This ligand forms a high spin neutral iron(II) complex that reacts with a variety of organoazides to yield transient Fe(III) imido radicals that are extremely potent hydrogen atom abstractors. The nature of these species is supported by full characterization of the Fe(III) amido products, kinetic studies, density functional computations and Mossbauer spectroscopy on the -C6H4-p-Bu-t substituted derivative.