Hydrothermal syntheses and crystal structures of two organic-inorganic hybrid molybdovanadates based on [V2Mo6(OH)2O24]4- and [VMo12O40]3- polyoxoanions

Two new organic-inorganic hybrid cobalt-molybdovanadates [Co(phen)(3)]H-2[H2V2Mo6O26]center dot 7H(2)O (1) and [Co(2,2'- bipy)(3)][Na(H2O)(7)][VMo12O40] (2) have been hydrothermally synthesized and structurally characterized by elemental analyses, IR, UV, XPS spectroscopy, thermogravimetric (TG) analyses, and X-ray single crystal diffraction. The molecular structure of 1 consists of a [V2Mo6(OH)(2)O-24](4-) polyoxoanion, a [Co(phen)(3)](2+), two H+ and seven lattice water molecules. The structure of [V2Mo6(OH)(2)O-24](4-) consists of six MoO6 octahedra and two VO4 tetrahedra; six MoO6 octahedra are linked by edge-sharing oxygens forming a {Mo-6} ring, and two VO4 tetrahedra cap opposite sides of the {Mo-6} ring. The molecular structural unit of 2 is constructed from a typical Keggin-type [VMo12O40](3-) polyoxoanion and a [Co(2,2'-bipy)(3)](2+) cation and a Na+ countercation; Co2+ is coordinated by six nitrogens from three 2,2'-bipyridines forming a distorted octahedron.