Social Chiral Self-Sorting Synthesis of [9]Cycloparaphenylene-Pillar[5]arene Heterochiral Multicavity Macrocyclic Trimers with Circularly Polarized Luminescence.

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.