The Hydrous Sodium Oxotellurates(VI) Na[TeO(OH)
<sub>5</sub>
], Na
<sub>2</sub>
[TeO
<sub>2</sub>
(OH)
<sub>4</sub>
], Na
<sub>4</sub>
[Te
<sub>2</sub>
O
<sub>6</sub>
(OH)
<sub>4</sub>
](H
<sub>2</sub>
O)
<sub>6</sub>
, and a Third Polymorph of Anhydrous Na
<sub>2</sub>
[TeO
<sub>4</sub>
]
previously reported cubic symmetry and the presence of a fourfold superstructure for (I), whereas (II) – (IV) crystallize in new structure types. Common features of the four sodium oxotellurate(VI) structures are [TeO6] octahedra. They are isolated in the structures of (I) and (II), condensed into a dinuclear [Te2O6(OH)4]4– anion in (III) and into an infinite zigzag 1∞[TeO4/2O2/1]2– chain in (IV).
化合物 Na[TeO(OH)5] (I)、Na2[TeO2(OH)4] (II)、Na4[Te2O6(OH)4](H2O)6 (III) 和第三种多晶型物的单晶(表示为γ-)无水Na2[TeO4](IV)分别从水溶液(I 和III)、水热条件(II)和NaNO3 熔体(IV)中获得。基于单晶 X 射线衍射数据的结构测定揭示了先前报道的立方对称性的降低和(I)的四重超结构的存在,而(II)-(IV)以新的结构类型结晶。四种氧代碲酸钠 (VI) 结构的共同特征是 [TeO6] 八面体。它们在 (I) 和 (II) 的结构中被隔离,在 (III) 中缩合为双核 [Te2O6(OH)4]4– 阴离子并形成无限锯齿形 1∞[TeO4/2O2/1]2– 链在(四)。四种结构中钠阳离子的配位数从四到七不等。通过热分析测量(热重法、差示扫描量热法、差热分析)和原位粉末 X 射线衍射研究了 (I)、(II)