Formation of Diquinoline Molecular Bricks and Their Assembly into Lattice Inclusion Compounds

The dibromodiquinoline derivative 2 yields crystalline lattice inclusion compounds with a wide range of guest molecules. The solvent-free crystal structure is also formed. In all these, pairs of dibromodiquinoline molecules form centrosymmetric brick-like dimers by means of three different aromatic edge−face (EF) interactions. The resultant (EF)6 building blocks, which are virtually identical across the series of 13 crystal structures described, act as tectons that pack into layers. Guest molecules occupy interlayer spaces near the corners of the tectons, with the host−guest attractions acting as molecular mortar and allowing variation of the inclusion structures dependent on guest size, shape, and functionality. The apohost crystal structure demonstrates that guest-free packing of these molecular bricks (analogous to the dry stone construction method) is also favorable. The molecular substitution of a dibromodiquinoline unit required to ensure dimeric (EF)6 tecton formation is explained.

二溴二喹啉衍生物2可与多种客体分子形成结晶晶格包合物，同时亦可生成无溶剂晶体结构。在所有此类体系中，成对的二溴二喹啉分子通过三种不同的芳香环边面（edge-face, EF）相互作用，形成中心对称的砖状二聚体。所得的(EF)₆结构基元在本文所述的13种晶体结构系列中几乎完全一致，作为结构构筑单元（tecton）堆积形成层状结构。客体分子占据结构构筑单元边角附近的层间空间，主客体相互作用充当分子黏合剂，使得包合结构可随客体分子的尺寸、形状与官能团发生变化。空主体（apohost）晶体结构表明，此类分子砖的无客体堆积方式（类比干砌石施工法）同样具备可行性。本文还阐明了为确保二聚体(EF)₆结构构筑单元形成所需的二溴二喹啉单元的分子取代修饰策略。