Syntheses, Characterization and Catalytic Properties of Two New Wells-Dawson Molybdosulfates

TWO new wells-Dawson compounds [C5N2H14](2)[(S2Mo18O62)-O-VI]center dot 8H(2)O (1) and [C5N2H14](8)(H3O)(2)[(S2Mo2Mo16O62)-Mo-V-O-VI]3 center dot (C5H5N)(2) (2) have been synthesized and characterized by single crystal X-ray analysis, IR spectra and elemental analysis. Single crystal X-ray diffraction confirms that compound 1 crystallizes in orthorhombic, a=1.799 29(17) nm, b=1.35804(13) nm, c=1.419 26(13) nm, V=3.4680(6) nm(3), Z=2. Compound 2, monoclinic, a=2.2665(3) nm, b =1.374 9(2) nm, c=3.291 2(5) nm, beta= 104.31 (0)degrees, V=9.938(2) nm(3), Z=4. Both compound 1 and 2 are built up of the Dawson-type molybdosulfate anions, full protonated /V-methylpiperazine cations. The catalytic result in the oxidation of styrene indicates that the mixed Mo (V)/Mo (VI) compound 2 has higher catalytic activity than 1. CCDC: 783378, 1; 783379, 2.