Chiralization of diamond nets: Stretchable helices and chiral and achiral nets with nearly identical unit cells
Chiralization of diamond nets: Stretchable helices and chiral and achiral nets with nearly identical unit cells
复制标题
DOI：
10.1002/anie.200701374
复制
发表时间：
2007-01-01
影响因子：
16.6
通讯作者：
Bu, Xianhui
中科院分区：
文献类型：
--
作者：
Zhang, Jian;Bu, Xianhui
由于纯手性固体在对映选择性过程中的潜在应用，目前对它们的兴趣正在迅速扩大。[1-7]对于无机氧化物如沸石，其中基本结构构建单元如[SiO4] 4 β和[AlO4] 5 β或次级构建单元如[Si4Al4O16] 4 β中的双四元环是非手性的，手性必须来自非手性单元的空间组织（通常是螺旋）。沸石B（多晶型A）是一种罕见的手性多孔硅铝酸盐，但由于堆积无序，其纯的对映体尚未制备。[8]产生沸石B型材料的愿望促使研究人员使用手性分子（如胺[9]或金属络合物[10]）作为模板来诱导手性。然而，用于此目的的手性物种倾向于在水热条件下外消旋化或倾向于直接合成低维结构。最近金属有机骨架材料（MOFs）的成功[11]开辟了合成纯手性固体的新途径，甚至是从非手性前体合成。[12]已经发现许多MOF采用在简单无机固体中通常已知的骨架拓扑结构。[13]不幸的是，最常见的手性网（石英）很少被这些骨架固体采用，而非手性金刚石网经常出现。考虑到金刚石网的普遍性，将其转化为手性网的方法应该引起普遍兴趣。此外，开发的金刚石网络的手性化的方法可以扩展到其他四连接网络，如那些代表的沸石。[1-5然而，尽管对手性骨架材料进行了深入的研究，但具有四连接拓扑结构的纯手性3D骨架仍然很少。此外，对映体纯和外消旋配体的结构导向效应的比较研究应该是特别感兴趣的，因为这样的研究可以发现调节纯手性固体结晶过程的重要因素。因为涉及对映体纯和外消旋配体的结晶过程由于以下原因而具有根本差异：
Current interest in homochiral solids is rapidly expanding because of their potential applications in enantioselective processes.[1–7] For inorganic oxides such as zeolites in which the basic structural building units such as [SiO4] 4À and [AlO4] 5À or secondary building units such as the double four-membered rings in [Si4Al4O16] 4À are achiral, the chirality must come from the spatial organization (usually helices) of achiral units. Zeolite b (polymorph A) is a rare chiral porous aluminosilicate, but its pure enantiomer has not yet been prepared because of the stacking disorder.[8] The desire to create materials of the zeolite b type has motivated researchers to use chiral molecules (such as amines [9] or metal complexes [10]) as templates to induce the chirality. However, chiral species used for this purpose tend to racemize under hydrothermal conditions or have a tendency to direct the synthesis of low-dimensional structures. Recent successes with metal–organic framework materials (MOFs)[11] have opened up new routes towards the synthesis of homochiral solids, even from achiral precursors.[12] Many MOFs have been found to adopt framework topologies commonly known in simple inorganic solids.[13] Unfortunately, the most common chiral net (quartz) is rarely adopted by these framework solids, whereas the achiral diamond net frequently occurs. Considering the ubiquity of the diamond net, a method for its conversion into the chiral net should be of general interest. Furthermore, the method developed for chiralization of the diamond net may be extensible to other four-connected nets such as those represented by zeolites.Homochiral solids can be constructed from enantiopure ligands.[1–5, 14–16] However, despite intensive research on chiral framework materials, homochiral 3D frameworks with the four-connected topology remain rare. Furthermore, comparative studies on the structure-directing effects of both enantiopure and racemic ligands should be of particular interest, because such studies can uncover important factors regulating the crystallization process of homochiral solids. Because the crystallization processes involving enantiopure and racemic ligands have fundamental differences owing to