Metallo‐Supramolecular Octahedral Cages with Three Types of Chirality towards Spontaneous Resolution
Xu Chen, Quanjie Lin, Chuan Shan, Xin Han, Hao Wang, Hao Wang, Heng Wang, Heng Wang, Wenjing Zhang, Zhi Chen, Chenxing Guo, Yinghao Xie, Xiujun Yu, Bo Song, Heng Song, Łukasz Wojtas, Xiaopeng Li
Abstract
Abstract Chirality is one of the most important intrinsic properties of (supra)molecules. In this study, we obtained enantiomeric metallo‐supramolecular octahedra without using any chiral sources. Such cages were self‐assembled by prochiral trispyridine ligand L based on a C 3h truxene core and Cu II salts. Crystallization of the cages with BF 4 − as counterions afforded racemate crystals; while crystallizations of cages with ClO 4 − and OTf − as counterions resulted in conglomerates with spontaneous resolution. Three types of chirality were observed in each cage, including planar chirality of the truxene core, axial chirality from the pyridyl and truxene moieties, and propeller chirality of the pyridyl‐Cu II coordination sites. The cages reported here are among the largest discrete synthetic metallo‐supramolecules ever reported with chiral self‐sorting behavior. Remarkably, the chiral cages exhibited very slow racemization even at low concentrations, suggesting their high stability in solution.