Formation of low-spin peroxoiron(III) complexes in Gif-type catalytic systems

New low-spin peroxoiron(III) complexes active towards cyclohexene and cyclohexane have been observed in the reaction of [Fe 2 O(bpy) 4 ·2H 2 O](NO 3 ) 4 and [Fe 2 O(Phen) 4 ·2H 2 O](NO 3 ) 4 with HOOH in a Py/AcOH solvent system.