Abstract
Imidyl and nitrene metal species play an important role in the N-functionalisation of unreactive C-H bonds as well as the aziridination of olefines. We report on the synthesis of the trigonal imido iron complexes [Fe(NMes)L(2)](0,-) (L = -N{Dipp}SiMe(3)); Dipp = 2,6-diisopropyl-phenyl; Mes = (2,4,6-trimethylphenyl) via reaction of mesityl azide (MesN(3)) with the linear iron precursors [FeL(2)](0,-). UV-vis-, EPR-, (57)Fe Mössbauer spectroscopy, magnetometry, and computational methods suggest for the reduced form an electronic structure as a ferromagnetically coupled iron(ii) imidyl radical, whereas oxidation leads to mixed iron(iii) imidyl and electrophilic iron(ii) nitrene character. Reactivity studies show that both complexes are capable of H atom abstraction from C-H bonds. Further, the reduced form [Fe(NMes)L(2)](-) reacts nucleophilically with CS(2) by inserting into the imido iron bond, as well as electrophilically with CO under nitrene transfer. The neutral [Fe(NMes)L(2)] complex shows enhanced electrophilic behavior as evidenced by nitrene transfer to a phosphine, yet in combination with an overall reduced reactivity.