Deprotonation of low-spin mononuclear iron(III)–hydroperoxide complexes give transient blue species assigned to high-spin iron(III)–peroxide complexes

Purple iron(III)–hydroperoxide complex ions [Fe(Rtpen)(η1-OOH)]2+ can be reversibly deprotonated to give transient blue species showing spectroscopic properties consistent with iron(III)–peroxide complexes; a novel ferryl species is produced in MS/MS experiments with the iron(III) hydroperoxide ion.