α－一铌二钼十五钨磷杂多酸盐的合成和性质研究

Synthesis and Properties of α-Molybadotungstoniobic Diphosphates

合成了通式为α－Ｍ＿（７－ｘ）Ｈ＿ｘ［Ｐ＿２Ｗ＿（１５）Ｍｏ＿２ＮｂＯ＿（６２）］·ｘＨ＿２Ｏ［Ｍ＝Ｋ~＋，（ＣＨ＿３）＿４Ｎ~＋，（Ｃ＿２Ｈ＿５）＿４Ｎ~＋，（Ｃ＿４Ｈ＿９）＿４Ｎ~＋］的４种盐．用ＩＲ、ＵＶ吸收光谱、极谱、^（１８３）ＷＮＭＲ、ＸＰＳ和ＸＲＤ等方法对其进行了表征，确认三取代的位置是在Ｄａｗｓｏｎ结构的同一“极位”．研究了取代Ｗ原子数目对^（１８３）ＷＮＭＲ化学位移的影响，发现“极位”Ｗ原子的^（１８３）ＷＮＭＲ化学位移平均值与取代原子数目呈线性关系．

Four kinds of new molybdotungstoniobic diphosphates with the Dawson structure, formulated as α-P_2W_(15)Mo_2NbO , are prepared and characterized by IR, UV spectra,polarography and ￣(183)W NMR which show that the same 'polar' W atoms in the Dawson frames are substituted. The mean value of ￣(183)W chemical shifts of the 'polar' group varies linearly with the number of substituted atoms in the opposite polar group.