Redox-triggered on/off coordination of a bridgehead nitrogen donor in a tripodal iron complex

We report the unprecedented redox-triggered on/off coordination of a bridgehead nitrogen donor in an iron complex of the tripodal ligand 2,2ʹ,2"-nitrilotribenzoate; the complex is an efficient redox catalyst for H2O2 oxidation of hydroquinone while complexes of related ligands are inactive.