钨钼杂多酸及其盐与二甲基亚砜加合物的制备和性质研究

Syntheses and Properties of Adducts Between Heteropoly Tungstic and Molybdic Acids and Their Salts with Dimethyl Sulfoxide

在乙腈和水的混合溶剂中制备了9种钨钼杂多酸和杂多酸盐的二甲基亚砜加合物。研究结果表明,加合物中杂阴离子的Keggin结构基本不变。配体DMSO以S=O键上的氧作为配位原子,它不直接与杂阴离子骨架结构发生配位作用,而是与杂多酸中的质子氢或杂多酸盐中的金属阳离子以氢键或配位键相配位,生成的质子(钅羊)离子和金属配离子再通过离子缔合键与杂阴离子相结合,形成杂多酸或杂多酸盐加合物。

Nine dimethyl sulfoxide (DMSO) adducts of heteropoly tungstic and molybdic acids and their salts were synthesized in mixed solvent of acetonitrile and water. Their properties were characterized by IR, Raman, UV-Vis,1H and 13C NMR spectra, TG-DTA thermal analysis, and X-ray diffraction analysis. The results show that the coordinating atom of DMSO is the oxygen atom of S = O bond . In the adducts, the a-Keggin structure of heteropoly anions keeps well. The organic lig-ands do not coordinate directly with heteropoly anions, but with protons in heteropoly acids by hydrogen-bond, forming oxonium ions, or with metal cations in heteropoly acid salts by coordination bond, forming complex ions. The adducts lost their organic ligands in a few steps in the range of 100-450 ℃, and the a-Keggin structure of heteropoly anions decomposes as temperature is higher than 500 ℃-The crystallographic data of CaPW-DMSO and (Bu3NH)3PW-DMSO single crystals were also determined.