Iron(III) complexes of ethylenediamine derivatives of aminophenol ligands as models for enzyme–substrate adducts of catechol dioxygenases

In the present work, six N,N′-dimethylethylenediamine derivatives of substituted aminophenol ligands (H2LNEX, X: C, B, M, BM, Bu and OB) were synthesized by a convenient, green procedure. The mentioned ligands were characterized by 1H NMR and IR spectroscopies. iron complexes (FeLNEX, X: C, B, M, BM, Bu and OB) of mentioned ligands, have been synthesized and characterized by IR, UV–Vis, elemental analysis, single crystal X-ray diffraction, magnetic susceptibility studies and cyclic voltammetry techniques. X-ray structure analysis has revealed that Fe(III) centers were surrounded by two phenolates, two amine nitrogens and two oxygen atoms of acetylacetonate ligand similar to the proposed catechol-bound intermediate for catechol dioxygenase. The variable temperature magnetic susceptibility indicates paramagnetic iron(III) in monomer complexes. All complexes undergo a metal-centered reduction, and a ligand-centered oxidation.

Graphical abstractIron complexes of seven N,N′-dimethylethylenediamine derivatives of substituted aminophenol ligands were synthesized and characterized by IR, UV–Vis, elemental analysis, single crystal X-ray diffraction, magnetic susceptibility studies and cyclic voltammetry techniques.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Iron(III) complexes of ethylenediamine derivatives of aminophenol ligands. ► All complexes have monomer structures and paramagnetic properties. ► Electrochemical redox of iron(III) complexes was investigated.