Tungsten dioxo complex WO 2(C 9H 6NO) 2 was obtained via the low temperature solid-state reaction of(NH 4) 2WS 4, 8-hydroxyquinoline(8-hq) and(CH 3) 4NI, and it was characterized by means of elemental analyses, IR spectroscopy and X-ray diffraction analysis. The crystal of the title compound belongs to monoclinic, space group C2/c, with the crystal cell parameters: a=1.3316(3) nm, b=0.94444(19) nm, c=1.3485(3) nm, β=109.66(3)°, V=1.5970(6) nm 3, Z=6. The title compound possesses a supramolecular structure formed through hydrogen bonds and π-π stacking interactions. The third-order non-linear optical(NLO) properties of the title compound were also investigated. The third-order non-linear absorption coefficient α 2 and refractive index n 2 are 0.85×10 -11 m/W -1 and -1.5×10 -19 m 2/W, respectively. The third-order non-linear susceptibility χ (3) is 3.03×10 -13 esu for 3.8×10 -5 mol/L sample concentration.
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.
