Studies On The Synthesis, Characterization And Catalytic Property Of P/Mo/W Oxygen Clusters

The studies on the synthesis and property of metal-oxygen clusters have became an important field in recent years, not only because of their abundant structural types and topological novelty but also due to their potential application in the fields of absorption, catalysis, conductivity, storage of energy, optical material and host-guest chemistry, etc..In this paper,we obtained a new metal-oxygen cluster polymer,formula as [C₂N₂H₁₀]₆H₈[NaCr(P₄Mo₆O₃₁)₂]·5H₂O, which possess novel structure. The compound has been characterized by single crystal X-ray diffraction, elemental analysis, and IR. spectra. The result of structure analysis showed that the crystal belongs to triclinic system, space group P-1. In this compound, the adjacent [Cr(P₄Mo₆O₃₁)₂] cluster units with sandwich-like structure were connected together by the Na⁺ ions to form two-dimensional layers. The strong hydrogen bonds formed by the N-H of ethylenedimine with oxygen atom of the clusters linked the layers to generate three-dimensional supramolecular network. The compound with this type of structure was firstly reported.The Keggin-type phosphor-molybdenum-tungstic acid H₃PW₆Mo₆O₄₀·nH₂O was also prepared in this paper. Vanillin 1,2-propylene glycol acetal was synthesized from vanillin and 1,2- propylene glycol by using H₃PW₆Mo₆O₄₀·nH₂O as catalyst. The catalytic activity of the compound was investigated. The factors influencing the product yield were discussed, such as the molar ratio of aldehyde to alcohol, the reaction time, the amount and stability of the catalyst. The experimental result indicated that the compound is a perfect catalyst for the synthesis of vanillin 1,2-propylene glycol acetal.