Bis(μ-alkoxo)-bridged dinuclear iron(III) complexes of pyrazole-based ligands as models for iron-oxo proteins

The synthesis, characterization, magnetic properties and the reactivity studies of two new bis(μ-alkoxo)-bridged dinuclear iron(III) complexes, [Fe(nhep)Cl2(EtOH)]2 and [Fe(nhed)Cl2]2 are reported. In compound 1, the iron(III) center has a coordination number of six, with a slightly distorted octahedral geometry. In compound 2, the bulkier nhed ligand, with methyl groups at the 3- and 5-positions of the pyrazole ring, leads to a coordination number of five at the iron(III) center in a distorted square pyramidal geometry. The magnetic properties of both complexes indicate the presence of fairly weak antiferromagnetic exchange interactions between iron(III) ions.