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 [Fe(II)(L)2(OH)](BF4) (1) and [Fe(III)(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.

Novel Distorted Pentagonal-Pyramidal Coordination of Anionic Oxodiperoxo Molybdenum and Tungsten Complexes.

Model compounds for silica surfaces modified with metal complexes are provided by the mononuclear anionic diperoxo species 1 and the dinuclear complex anions 2 (M = Mo, W). They were obtained in fair to nearly quantitative yields by the reactions of Ph SiOH and [Ph Si(OH)] O, respectively, with an aqueous solution of [MO(O ) (H O) ].

[Mo S O (OH) (H O) ]: A Cyclic Molecular Cluster Based on the [Mo S O ] Building Block.

The pH-dependent self-condensation of the [Mo S O ] complex fragment gives the wheellike Mo cluster depicted on the right (ball-and-stick model; large balls: S, medium balls: O, small balls: Mo). Applying this synthetic strategy to other starting materials could provide access to other polyoxothiometalates with well-defined cavities.