Solvent-Modulated Formation of “Pac-man” and Capsular Host–Guest Bilayers from a Dicationic Ionic Liquid and C‑Butylpyrogallol[4]arene

The pyrogallol­[4]­arenes have been shown to act as versatile host macrocycles for a wide variety of guest molecules, including the imidazolium-based cations of ionic liquids. This report demonstrates the use of alkyl-linked geminal dications in the design of bilayers comprising dimeric host–guest complexes. The pivotal role of solvent choice in controlling the resultant solid-state structure is particularly highlighted. The synthesis and single-crystal X-ray diffraction structures of two dimeric host–guest cocrystals generated by the use of different solvents while employing identical host and guest species are presented to illustrate this point. In one solvent, a “Pac-man”-type dimeric host–guest complex is assembled into bilayer galleries. With a switch to an alternate crystallization solvent, a bilayer-type structure in which each layer is composed of alternating complexes of a capsule and two “offset dimers” is instead constructed.焦没食子酚[4]芳烃（pyrogallol[4]arene）类化合物已被证实可作为通用型主体大环，能够结合包括离子液体咪唑鎓阳离子在内的多种客体分子。本研究展示了利用烷基连接的偕二阳离子设计由二聚主客体复合物构成的双层结构的方法，特别强调了溶剂选择对最终固态结构的关键调控作用。为阐明该观点，本文合成了两组主体与客体物种完全一致、仅结晶溶剂不同的二聚主客体共晶，并解析了其单晶X射线衍射（single-crystal X-ray diffraction）结构：在第一种溶剂中，“吃豆人”型二聚主客体复合物组装为双层空腔结构；切换至另一种结晶溶剂后，则形成另一种双层结构，其中每层由胶囊型复合物与两个“偏移二聚体”交替排列构成。