Mono- or few-layer sheets of covalent organic frameworks (COFs) represent an attractive platform of two-dimensional materials that hold promise for tailor-made functionality and pores, through judicious design of the COF building blocks. But although a wide variety of layered COFs have been synthesized, cleaving their interlayer stacking to obtain COF sheets of uniform thickness has remained challenging. Here, we have partitioned the interlayer space in COFs by incorporating pseudorotaxane units into their backbones. Macrocyclic hosts based on crown ethers were embedded into either a ditopic or a tetratopic acylhydrazide building block. Reaction with a tritopic aldehyde linker led to the formation of acylhydrazone-based layered COFs in which one basal plane is composed of either one layer, in the case of the ditopic macrocyclic component, or two adjacent layers covalently held together by its tetratopic counterpart. When a viologen threading unit is introduced, the formation of a host–guest complex facilitates the self-exfoliation of the COFs into crystalline monolayers or bilayers, respectively.

单层或几层共价有机框架 (COF) 代表了一个有吸引力的二维材料平台，通过对 COF 构建块的明智设计，有望实现量身定制的功能和孔隙。但是，尽管已经合成了各种各样的层状 COF，但切割它们的层间堆叠以获得均匀厚度的 COF 片仍然具有挑战性。在这里，我们通过将假轮烷单元合并到其骨架中来划分 COF 中的层间空间。基于冠醚的大环主体被嵌入到双位或四位酰肼结构单元中。与三元醛连接体反应导致形成基于酰基腙的层状 COF，其中一个基面由任一层组成，在双位大环组分的情况下，或两个相邻层由其四位对应物共价结合在一起。当引入紫罗碱穿线单元时，主客体复合物的形成促进了 COF 分别自剥离成晶体单层或双层。