A new rubidium uranyl silicate, Rb2(UO2)2O(Si3O8) (1), was obtained using high-temperature approach from the melt in silica tubes. Its crystal structure was solved by direct methods: hexagonal, P6/m, a = 27.7992(7), c = 7.2346(2) Å, V = 4841.8(3) Å3, R 1 = 0.033. The structure of 1 represents a new structure type with unprecedented topology not observed before among U(VI) oxides and oxysalts. It is comprised of layers with large voids derived from the U3O8 structure formed exclusively by pentagonal UrO5 bipyramids. The low-occupied Rb sites are located in the interlayer space. The SiO4 silicate tetrahedra in the structure of 1 share vertices to form rolled [Si6O16]8− chains. The nanotubules [(UO2)(Si6O16)]6− penetrate through both U3O8-derived layers and Rb interlayer. These tubules are attached to the U3O8 derived sheets via uranyl-uranyl interactions and edge-sharing between silicate tetrahedra and UrO5 bipyramids.

中文翻译：

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Rb2[(UO2)2O(Si3O8)] 中的硅酸铀酰纳米管：合成和晶体结构

一种新型硅酸双氧铀铷，Rb2（UO2）2O(硅3氧8) (1)，是使用高温方法从石英管中的熔体中获得的。通过直接法求解其晶体结构：六方、磷6/米,A= 27.7992(7),C= 7.2346(2) 埃,V= 4841.8(3) 埃3,右 1= 0.033。1的结构代表了一种新的结构类型，具有前所未有的拓扑结构，在U(VI)氧化物和含氧盐中以前从未观察到过。它由具有源自 U 的大空隙的层组成3氧8完全由五边形组成的结构乌尔氧5双锥体。低占据的 Rb 位点位于层间空间。二氧化硅4硅酸盐四面体结构中1股顶点形成卷状[Si6氧16]8−链。纳米管[(UO2)(硅6氧16)]6−穿透两个U3氧8-衍生层和Rb夹层。这些小管连接到U3氧8通过铀酰-铀酰相互作用和硅酸盐四面体之间的边缘共享衍生片乌尔氧5双锥体。