三铝九钨杂多硅酸盐异构体的合成和性质研究

Preparation and Characterization of Trialuminononatungstosilicate Isomers

本文报道了八种新化合物 A-α-和 A-β-M_(5-m)H_m[H_2SiW_9Al_3(H_2O)_3O_(37)]·xH_2O(M=K,TMA,TEA,TBA)的合成、性质研究和结构确定.几种盐的红外和紫外光谱表明这两种异构体阴离子具有 Keggin 结构.四圆衍射实验测得 A-α-SiW_9Al_3-K 的晶体结构.极谱数据表明两个阴离子仍保持母体阴离子α-和β-SiW_9的还原形式,但其半波电位稍有降低.^(27)Al NMR 数据指出铝原子在阴离子中是八面体配位的,三个铝原子处于相同的化学环境中.紫外光谱、极谱和^(27)Al NMR谱均可区分两种异构体.也研究了两种阳离子在水溶液中的稳定性和几种盐的热稳定性.

The eight new compounds α-and β-M_(5-m)H_m [H_2SiW_9Al_3(H_2O)_3O_(37)]·xH_2O (M=K,TMA,TEA,TBA) has been prepared and characterized.They have the characteristicabsorption peaks of Keggin structure in IR and UV spectra.It is shown from theirpolarographic data that the two heteropoly anions retain the reduced patterns of theirparents,but differ in their E_(1/2) values.The ^(27)Al NMR data show that aluminiumatoms are coordinated octahedrally and in a same chemical environment.Theirstability in water and thermal stability have been examined.The structure of anionA-α-[SiW_9Al_3(H_2O)_3O_(37)]^(7-) has been determined.