Social Chiral Self‐Sorting Synthesis of [9]Cycloparaphenylene‐Pillar[5]arene Heterochiral Multicavity Macrocyclic Trimers with Circularly Polarized Luminescence
Shiyu Tan, Ye‐Qiang Han, Guangguo Wang, Liya Chen, Li Shao, Mingrui Xiao, Bohan Zhao, Feihe Huang, Bin Hua
Abstract
The precise synthesis of stereochemically controlled multicavity macrocyclic hosts based on pillar[n]arenes presents a significant challenge in supramolecular chemistry. This difficulty primarily stems from the spontaneous generation of planar chirality-induced stereoisomer mixtures during synthetic procedures, which considerably complicates the isolation process. In this study, we introduce a social chiral self-sorting strategy utilizing a triangular gold complex, enabling the stereochemically controlled synthesis of [9]cycloparaphenylene-pillar[5]arene trimers ([9]CPP-3P[5]A). Diverging from conventional synthetic approaches that typically yield four stereoisomers of pillararene trimers (pSSS, pRRR, pSSR, and pRRS), our methodology demonstrates selectivity, predominantly generating pSSR and pRRS isomers of [9]CPP-3P[5]A, with only trace amounts of pSSS and pRRR isomers. This stereoselectivity, as elucidated by crystallographic analysis, arises from the dynamic reorganization of Au─C σ-bonds during the assembly of the hexagold(I) complex, synergistically combined with specific phosphine ligand conformations and inter-pillararene interactions. The resulting chiral trimers exhibit circularly polarized luminescence (CPL) properties, which facilitates the fabrication of CPL-active supramolecular polymers by leveraging the superior host-guest complexation capability of the pillar[5]arene units, opening new avenues for the development of chiral functional materials.