Spectroscopic Characterization of a Hydroperoxo-Heme Intermediate: Conversion of a Side-On Peroxo to an End-On Hydroperoxo Complex

Modeling job: Protonation of a closed seven‐coordinate side‐on heme peroxide can switch its spin state from high‐ to low‐spin and convert the η2 binding fashion into a monodentate configuration to afford the corresponding hydroperoxide (see scheme). The end‐on low‐spin ferric hydroperoxo–heme species bear a covalently appended axial imidazole ligand and are easily prepared.