Stabilization of a high-spin three-coordinate Fe(iii) imidyl complex by radical delocalization.

High-spin, late transition metal imido complexes have attracted significant interest due to their group transfer reactivity and catalytic C-H activation of organic substrates. Reaction of a new two-coordinate iron complex, Fe{N( Bu)Dipp} (1, Dipp = 2,6-diisopropylphenyl), with mesitylazide (MesN) afforded a three-coordinate Fe-imidyl complex, Fe{N( Bu)Dipp}([double bond, length as m-dash]NMes) (2). X-ray crystallographic characterization of single crystals of 2 showed a long Fe-N distance of 1.