Faujasite (FAU) and zeolite A (LTA) are technologically important porous zeolites (aluminosilicates) because of their extensive use in petroleum cracking and water softening1,2. Introducing organic units and transition metals into the backbone of these types of zeolite allows us to expand their pore structures, enhance their functionality and access new applications3,4. The invention of metal–organic frameworks and zeolitic imidazolate frameworks (ZIFs) has provided materials based on simple zeolite structures where only one type of cage is present5,6,7,8,9. However, so far, no metal–organic analogues based on FAU or LTA topologies exist owing to the difficulty imposed by the presence of two types of large cage (super- and β-cages for FAU, α- and β-cages for LTA). Here, we have identified a strategy to produce an LTA imidazolate framework in which both the link geometry and link–link interactions play a decisive structure-directing role. We describe the synthesis and crystal structures of three porous ZIFs that are expanded analogues of zeolite A; their cage walls are functionalized, and their metal ions can be changed without changing the underlying LTA topology. Hydrogen, methane, carbon dioxide and argon gas adsorption isotherms are reported and the selectivity of this material for carbon dioxide over methane is demonstrated.

中文翻译：

八面沸石（FAU）和沸石A（LTA）是技术上重要的多孔沸石（铝硅酸盐），因为它们广泛用于石油裂解和水软化1,2中。将有机单元和过渡金属引入这些类型沸石的骨架中使我们能够扩展其孔结构，增强其功能性并获得新的应用3,4。金属-有机骨架和咪唑沸石骨架（ZIFs）的发明提供了基于简单沸石结构的材料，其中仅存在一种笼子类型5,6,7,8,9。但是，由于存在两种类型的大型笼子（FAU的超笼和β笼，LTA的α笼和β笼）所带来的困难，到目前为止，还没有基于FAU或LTA拓扑的金属有机类似物存在。 。在这里，我们确定了一种生产LTA咪唑酸酯框架的策略，该结构中的链节几何结构和链节之间的相互作用都起着决定性的结构指导作用。我们描述了三种多孔ZIF的合成和晶体结构，它们是沸石A的扩展类似物。它们的笼壁功能化，并且可以改变其金属离子，而无需改变底层的LTA拓扑结构。报告了氢气，甲烷，二氧化碳和氩气的吸附等温线，并证明了该材料对二氧化碳的选择性高于甲烷。