Novel iron(III) complexes of sterically hindered 4N ligands: regioselectivity in biomimetic extradiol cleavage of catechols

The synthesis and characterization of the iron(III) complexes of three linear diazapane-based 4N ligands containing two (6-methyl)pyridylmethyl or pyridyl-methyl or quinolylmethyl arms as functional models for the extradiol cleaving catechol dioxygenase enzymes is described. The cleavage produces obtained for iron(III) complexes depend strongly upon the ligand architecture as well as the mode of coordination of catecholate substrate to iron(III).