Synthesis and structure of iron(III) diamine-bis(phenolate) complexes

The structures and properties of six new iron(III) diamine-bis(phenolate) complexes are reported. Reaction of anhydrous FeX3 salts (where X = Cl or Br) with the diprotonated tripodal tetradentate ligands 2-pyridylamino-N, N-bis(2-methylene-4-methyl-6-tert-butylphenol), H-2[L-1], and N,N-dimethyl-N', N'-bis(2-methylene-4-methyl-6-tert-butylphenol)ethylenediamine, H-2[L-2], produces the trigonal bipyramidal iron(III) complexes, [L-1] FeCl 1, [L-1] FeBr 2, [L-2] FeCl 3 and [L-2] FeBr 4. Reaction of FeX3 with the related linear tetradentate ligand N, N'-bis(4,6-tert-butyl-2-methylphenol)-N, N'-bismethyl-1,2-diaminoethane, H-2[L-3], generates square pyramidal iron(III) complexes, [L-3] FeCl 5 and [L-3] FeBr 6. Complexes 1-6 have been characterized using electronic absorption spectroscopy and magnetometry. Single crystal X-ray molecular structures have been determined for complexes 1, 3, 5 and 6.