Characterization of Terminal Iron(III)–Oxo and Iron(III)–Hydroxo Complexes Derived from O2 Activation

O2 activation at nonheme iron centers is a common motif in biological systems. While synthetic models have provided numerous insights into the reactivity of high-valent iron–oxo complexes related to biological processes, the majority of these complexes are synthesized using alternative oxidants. This report describes O2 activation by an iron­(II)–triflate complex of the imino-functionalized tris­(pyrrol-2-ylmethyl)­amine ligand framework, H3[N­(piCy)3]. Initial reaction conditions result in the formation of a mixture of oxidation products including terminal iron­(III)–oxo and iron­(III)–hydroxo complexes. The relevance of these species to the O2 activation process is demonstrated through reactivity studies and electrochemical analysis of the iron­(III)–oxo complex.