Koike Masakazu, Asakura Yusuke, Sugihara Megumi, Kuroda Yoshiyuki, Tsuzura Hidehiro, Wada Hiroaki, Shimojima Atsushi, Kuroda Kazuyuki
Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan.
Dalton Trans. 2017 Aug 8;46(31):10232-10239. doi: 10.1039/c7dt01287j.
Silica sodalite was obtained using topotactic conversion of layered silicate RUB-15 through stepwise processes that consisted of the control of stacking sequence of the layers, interlayer condensation by refluxing, and elimination of intercalated guest species. The interlayer condensation of RUB-15, in which acetic acid was pre-intercalated between the layers to control the stacking sequence, afforded a sodalite framework containing organic guest species by refluxing in N-methylformamide (NMF). The pre-intercalated acetic acid molecules were largely replaced with NMF. This formation process of silica sodalite containing large amounts of intercalated organic guest species is in clear contrast to the previously reported process that used direct calcination of an intercalation compound of layered RUB-15 accommodating acetic acid between the layers. Calcination of the condensed product provided sodalite with fewer defects than the directly calcined product, thus indicating the advantage of the stepwise process. The method reported here is useful for the preparation of pure silica sodalite with relatively low defects and plate-like morphology.
通过逐步过程对层状硅酸盐RUB-15进行拓扑转化得到了方钠石，该过程包括控制层的堆积顺序、通过回流进行层间缩合以及去除插层客体物种。RUB-15的层间缩合过程中，在层间预先插入乙酸以控制堆积顺序，通过在N-甲基甲酰胺（NMF）中回流得到了含有有机客体物种的方钠石骨架。预先插入的乙酸分子大部分被NMF取代。这种含有大量插层有机客体物种的方钠石的形成过程与先前报道的直接煅烧层状RUB-15的插层化合物（层间容纳乙酸）的过程形成了鲜明对比。缩合产物的煅烧提供了比直接煅烧产物缺陷更少的方钠石，从而表明了逐步过程的优势。这里报道的方法对于制备具有相对低缺陷和板状形态的纯方钠石是有用的。
