Research Center for Compact Chemical Systems, National Institute of Advanced Industrial Science and Technology, AIST Tohoku, Sendai, Miyagi 983-8551, Japan.
Inorg Chem. 2011 Mar 21;50(6):2294-301. doi: 10.1021/ic1020065. Epub 2011 Feb 4.
A new layered silicate, HUS-1, was synthesized by hydrothermal synthesis using decomposed FAU- and *BEA-type zeolites as nanosized silica parts. Structural analyses by X-ray powder diffractometry and solid-state magic-angle-spinning (MAS) NMR spectroscopy revealed that HUS-1 has a layered structure containing a silicate layer per unit cell along a stacking direction. Its framework topology is similar to that of SOD-type zeolites and consists of a halved sodalite cage, which includes four- and six-membered Si rings. Structure refinement by the Rietveld method showed that tetramethylammonium (TMA) ions used as a structure-directing agent (SDA) were incorporated into the interlayer. The four methyl groups of the TMA molecule were located orderly in a hemispherical cage in the silicate layer, which suggests restraint of molecular motion. The interlayer distance is estimated at about 0.15 nm, which is unusually short in comparison with that in other layered silicates (e.g., β-HLS or RUB-15) with similar framework topologies. The presence of hydrogen bonding between adjacent terminal O atoms was clearly revealed by the (1)H MAS NMR spectroscopy and by electron-density distribution obtained by the maximum entropy method.
一种新型层状硅酸盐 HUS-1 通过水热合成法用分解的 FAU 和 *BEA 型沸石作为纳米级硅部分合成。X 射线粉末衍射和固态魔角旋转（MAS）NMR 光谱结构分析表明，HUS-1 具有层状结构，沿堆积方向每个单元包含一个硅酸盐层。其骨架拓扑与 SOD 型沸石相似，由减半的方钠石笼组成，其中包含四元和六元 Si 环。Rietveld 法结构精修表明，用作结构导向剂（SDA）的四甲基铵（TMA）离子被掺入层间。TMA 分子的四个甲基有序地位于硅酸盐层的半球形笼中，这表明分子运动受到限制。层间距离估计约为 0.15nm，与具有类似骨架拓扑的其他层状硅酸盐（例如β-HLS 或 RUB-15）相比，该距离异常短。通过（1）H MAS NMR 光谱和通过最大熵法获得的电子密度分布清楚地表明相邻末端 O 原子之间存在氢键。
