Synthesis And Structural Characterization Of Sandwich-type Antimoniotungstate

The transition metal substituted polyoxometalate structures with its diversity, ithas excellent performance in medicine、catalytic、magnetic、optical sensors andmaterials science, particularly in the more recent years, the sandwich structure andthe expansion of the structure research polyoxometalates has been widespreadconcern.In this thesis, trivacant Keggin type heteropoly anions as precursors usingconventional synthesis and transition metal ions react by changing the reactionconditions, synthesized three Krebs-sandwich-type tungstoantimonates. Byelemental analysis, infrared spectroscopy, thermal gravimetric analysis of itsstructure were studied.In an acidic environment, the successful synthesis and characterization of threesandwich-type POMs:[Na(H2O)3Na(H2O)4Na(H2O)5]2[{Co2(H2O)6}0.75{W2(H2O)6}0.25{Co2(OH)4}0.25{W2(OH)4}0.75(B-β-SbW9O33)2]·17H2O (1)[Na(H2O)3Na(H2O)4Na(H2O)5]2[{Ni2(H2O)6}0.75{W2(H2O)6}0.25{Ni2(OH)4}0.25{W2(OH)4}0.75(B-β-SbW9O33)2]·16H2O (2)[Na(H2O)3Na(H2O)4]2[{Cu2(H2O)6}0.75{W2(H2O)6}0.25{W(OH)2}2(B-β-SbW9O33)2]·16H2O (3)Compound (1) is synthesised by using two trivacant [B-β-SbW9O33]9-anionfragment as a basic building blocks, which connect transition metal have formedsandwich type Polyoxometalates. The transition-metal-containing polyoxoanions areconnected into monoclinic system space group p21/n-dimensional chain compoundsvia the two different kinds of dual-core [Na2(H2O)6]2+units and two [Na(H2O)4]+units, and this compound contains three different types of Na+cations. Compound (2)and (3) are similar to the structure (1). The structure of compounds werecharacterized by using TGA, IR, single-crystal X-ray. The study found threecompounds have the ability to degrade dye, We have tested the catalytic properties ofdegradation of three different dyes, finding degradation is better for crystal violetand UV-light and oxygen can accelerate the degradation rate, We also findedmechanism of degradationon of dye usingin Compound (2) in the dark and underlight conditions may be different.