Mononuclear diastereopure non-heme Fe(II) complexes of pentadentate ligands with pyrrolidinyl moieties: Structural studies, and alkene and sulfide oxidation

Mononuclear iron(II) complexes of enantiopure Py(ProOH)2 (2) and Py(ProPh2OH)2 (3) ligands have been prepared with FeCl2 and Fe(OTf)2 · 2MeCN. Both ligands coordinate to the metal in a pentadentate fashion. Next to the meridional N,N′,N-coordination of the ligand, additional coordination of the oxygen atoms of both hydroxyl groups to the metal is found in complexes 4–7. Complex [FeCl(2)](Cl) (4) shows an octahedral geometry as determined by X-ray diffraction and is formed as a single diastereoisomer. The solution structures of complexes 4–7 were characterized by means of UV–Vis, IR, ESI-MS, conductivity and CD measurements. The catalytic potential of these complexes in the oxidation of alkenes and sulfides in the presence of H2O2 is presented.