A novel 3 D compound, [H 0.5 CoP 0.5 O 2.5 ], was hydrothermally synthesized and structurally characterized by singly crystal X ray diffraction, ICP, elemental analysis and IR spectra. The compound crystallizes in orthorhombic system, space group Pnnm with a =0.805 1(2) nm, b =0.838 09(13) nm, \{ c =\}0.595 0(2) nm, V =0.401(2) nm 3, Z=1, D =1.669 Mg/cm 3, R=0.049 1, wR =0.153 2.
A Hydrothermal reaction of MoO 3, NiCl 2·6H 2O, WO 3 and H 2O with a molar ratio of 1∶0.6∶1∶83.3 gives a rhombic-shaped black crystal [NiMo 12O 40H 10{Ni(H 2O) 3} 4]. It crystallizes in a tetragonal system with space group I4 1/amd and unit cell parameters a=b=1.518 4(2) nm, c=3.082 9(6) nm, Z=4, V=7.108(2) nm 3, R=0.067 1, wR=0.217 8. The compound possesses a four-capped Keggin structure. The structure of the Keggin- [NiMo 12O 40H 10] 8- consists of twelve MoO 6 octahedrons and a NiO 4 tetrahedron on the center. Four [Ni(H 2O) 3] 2+ at the cap positions are linked to Keggin-structure by three μ 3-O, respectively. The calculation of bond valence shows that the oxidation state of Mo in the compound is +5.
