The hydrothermal synthesis and characterization of an organic-inorganic hybrid compound [ WO 3 (2,2∞-bipy)] (2,2∞-bipy=2,2∞-bipyridine) is presented. This compound was characterized by various techniques including Raman and IR spectroscopy, XRD and thermogravimetric analysis. Structural analysis of the compound by Raman and IR data shows that it has a novel tungstate structure with 2,2∞-bipy coordinated to tungsten. The X-ray powder diffraction data of the compound are indexed to a monoclinic cell with a=14.313( 4), b=9.603(2), c=7.288(2) A ˚, b=102.07(2)°. The structure of [ WO 3 (2,2∞-bipy)] adopts a chain-like framework consisting of corner-shared distorted octahedra ( WO 4 N 2 ) with 2,2∞-bipy acting as a bidentate ligand whose rings fan out from the chain. Upon heating, [ WO 3 (2,2∞-bipy)] retains its structural integrity until 300 °C, followed by a gradual loss of 2,2∞-bipy which leads to the formation of WO 3 at ca. 475 °C. The thermal decomposition is observed to proceed through a transitional intermediate, [ W 4 O 12(2,2∞-bipy)], the structure of which is proposed and discussed.

In this paper, we explored the possibility of building halogen bonds between polyoxometalate anions by synthesizing a series of polyoxometalate clusters covalently linked to different halogen atoms. Among these samples, the polyoxometalate hybrids containing bromide and iodine atoms exhibited both halogen and hydrogen bonding interactions between the hybrid anions, leading to novel 3D framework assemblies.