A binuclear molybdenum oxyfluoride: μ-oxido-bis[(2,2′-bipyridyl)fluoridodioxidomolybdenum(VI)]

The title compound, [Mo2F2O5(C10H8N2)2], is a centrosymmetric binuclear molybdenum(VI) species with the metal atoms in a distorted octahedral environment. The coordination geometries of the symmetry-equivalent molybdenum sites are defined by the cis-terminal oxide groups and the N-atom donors of the bipyridyl ligand in the equatorial plane with axial F and bridging O atoms. The bridging O atom occupies a center of symmetry. The molecules stack in the a-axis direction, and the crystal packing is stabilized by weak intra- and intermolecular C—H⋯O and C—H⋯F hydrogen bonds.

The title compound, [Mo 2 F 2 O 5 (C 10 H 8 N 2 ) 2 ], is a centrosymmetric binuclear molybdenum(VI) species with the metal atoms in a distorted octahedral environment. The coordination geometries of the symmetry-equivalent molybdenum sites are defined by the cis-terminal oxide groups and the N-atom donors of the bipyridyl ligand in the equatorial plane with axial F and bridging O atoms. The bridging O atom occupies a center of symmetry. The molecules stack in the a-axis direction, and the crystal packing is stabilized by weak intraand intermolecular C-HÁ Á ÁO and C-HÁ Á ÁF hydrogen bonds.

Comment
The contemporary interest in metal oxides reflects their vast compositional range and structural versatility. One area of oxide chemistry that has witnessed considerable activity is that of zeolitic materials, compositions forming open-framework structures consisting of metal oxide components and organic moieties acting as charge compensating cations, structure-directing agents or ligands. While the majority of these materials are simple oxides or oxyanion based, the introduction of fluoride to substitute for some oxo-groups provides a novel class of oxyfluorometalates (Adil et al., 2010;Jones, et al., 2010;Michailovski, et al., 2006 and2009;Burkholder and Zubieta, 2004).
In the course of our investigations of organic-inorganic oxide hybrid materials of molybdenum and vanadium, we have noted that Fis a useful mineralizing agent. However, under appropriate conditions of temperature and stoichiometry, fluoride may be incorporated into the coordinate covalent framework of the material to provide novel oxyfluorometalate composites. In the course of these investigations, the title compound [Mo 2 F 2 O 5 (bpy) 2 ] was isolated.
The compound crystallizes in the monoclinic space group P2 1 /c with two binuclear molecules per unit cell. The bridging oxo-group sits at a center of symmetry producing equivalent molybdenum sites. The coordination geometry is distorted  (Table).

Refinement
All the hydrogen atoms were discernable in the difference electron density map and were freely refined.