Cooperative Binding and Chirogenesis in an Expanded Perylene Bisimide Cyclophane

Additional data to report https://doi.org/10.1021/jacs.4c08073: The encapsulation of more than one guest molecule into a synthetic cavity is a highly desirable yet a highly challenging task to achieve for neutral supramolecular hosts in organic media. Herein, we report a neutral perylene bisimide cyclophane, which has a tailored chiral cavity with an interchromophoric distance of 11.2 Å, capable of binding two aromatic guests in a π-stacked fashion. Detailed host–guest binding studies with a series of aromatic guests revealed that the encapsulation of the second guest in this cyclophane is notably more favored than the first one. Accordingly, for the encapsulation of the coronene dimer, a cooperativity factor (α) as high as 485 was observed, which is remarkably high for neutral host–guest systems. Furthermore, a successful chirality transfer, from the chiral host to encapsulated coronenes, resulted in a chiral charge-transfer (CT) complex and the rare observation of circularly polarized emission originating from the CT state for a noncovalent donor–acceptor assembly in solution. The involvement of the CT state also afforded an enhancement in the luminescence dissymmetry factor (glum) value due to its relatively large magnetic transition dipole moment. The 1:2 binding pattern and chirality-transfer were unambiguously verified by single-crystal X-ray diffraction analysis of the host–guest superstructures.补充数据详见：https://doi.org/10.1021/jacs.4c08073：在有机介质中，利用中性超分子主体（supramolecular host）将多个客体分子封装至合成空腔内，是一项兼具重要应用价值与极高挑战的研究课题。本文报道一种中性苝二酰亚胺环芳（perylene bisimide cyclophane）主体，其拥有定制化手性空腔，生色团间距为11.2埃（Å），可通过π堆叠模式结合两个芳香族客体分子。针对一系列芳香族客体开展的详细主客体结合研究表明，该环芳主体对第二位客体分子的封装相较于第一位显著更具热力学优势。在针对蔻二聚体（coronene dimer）的封装实验中，我们观测到协同因子（α）高达485，这一数值在中性主客体体系中属于极高水平。此外，手性主体可将手性成功传递至被封装的蔻分子，形成手性电荷转移（charge-transfer, CT）复合物；同时在溶液中非共价供体-受体组装体中，我们罕见地观测到源自CT态的圆偏振发射现象。由于CT态具有相对较大的磁跃迁偶极矩，其参与作用还提升了发光不对称因子（luminescence dissymmetry factor, g_lum）的数值。通过对主客体超结构的单晶X射线衍射分析，我们明确验证了1:2的结合模式与手性传递过程。