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

Abstract

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), H₂[L₁], and N,N-dimethyl-N′,N′-bis(2-methylene-4-methyl-6-tert-butylphenol)ethylenediamine, H₂[L₂], produces the trigonal bipyramidal iron(III) complexes, [L₁]FeCl 1, [L₁]FeBr 2, [L₂]FeCl 3 and [L₂]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, H₂[L₃], generates square pyramidal iron(III) complexes, [L₃]FeCl 5 and [L₃]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.