Monomeric Iron(II) Hydroxo and Iron(III) Dihydroxo Complexes Stabilized by Intermolecular Hydrogen Bonding

Using the multidentate ligand bis(N-methylimidazol-2-yl)-3-methylthiopropanol (L), the mononuclear iron(II) hydroxo and iron(III)
dihydroxo complexes [FeII(L)2(OH)](BF4) (1) and [FeIII(L)2(OH)2](BF4) (2) have been synthesized and characterized by X-ray
diffraction and spectroscopic methods. The X-ray data suggest
that the remarkable stability of the Fe−OH bond(s) in both
compounds results from intermolecular hydrogen-bonding interactions between the hydroxo ligand(s) and the tertiary hydroxyl of
the L ligands, which prevent further intermolecular reactions.