粉状白钨酸的研究(Ⅻ)——某些聚钨酸有机铵盐的合成和性质

Studies on Powdery White Tungstic Acid(Ⅻ)--Preparation and Properties of Certain Organic Ammonium Polytungstates

以粉状白钨酸和三种有机铵——乙二胺、乙醇胺和异丙胺为原料,分别合成了偏钨酸盐和仲钨酸盐。通过紫外,红外光谱、核磁共振谱以及极谱测定,研究了三种不同类型有机胺聚钨酸盐的组成与性质,发现乙醇胺和异丙胺的偏钨酸盐具有光敏性。

Ethylene diamine and ethanol amine react with white powdery tungstic acid to form metatungstates and paratungstates at weak acidic and neutral media respectively. Isopropyl amine forms metatungstate at pH 3-7 region. The compositions of these polytugstates are shown in table 1. UV, 1R, PMR and polarographic studies have all been performed for these compounds. It has been found that only the metatungstates of ethanol amine and isopropyl amine are photosensitive. On exposure to sunlight or ultraviolat ray, significant absorption peaks appear at 620 and 860nm respectively. The decay rates concerning extinction of the peaks obey the pseudo-first order rate equation.