Harnessing Point–Planar Chirality Synergy: Crystallization‐Enabled Resolution of Pillar[5]arene Rotaxanes With Tunable Circularly Polarized Luminescence

Abstract

ABSTRACT Immobilizing the planar chirality inherent to pillar[5]arene remains a challenge in supramolecular chemistry. Herein, we report a rational strategy for constructing chiral pillar[5]arene‐based [2]rotaxanes and controlling their planar chirality by incorporating sterically bulky chiral stopper groups at both ends of the axle units. Using this approach, six structurally distinct [2]rotaxanes were efficiently resolved via simple recrystallization, achieving yields exceeding 90% and diastereomeric ratios ( d.r .) above 99.5:0.5. These molecules can be classified as either synergistic or mismatched point–planar chiral [2]rotaxanes. Remarkably, only the synergistic point–planar chiral [2]rotaxanes exhibited tunable circularly polarized luminescence (CPL), with a maximum | g lum | value of 0.02, whereas the mismatched configurations yielded no detectable CPL signal. This work overcomes a fundamental bottleneck in the scalable, stereocontrolled synthesis of chiral pillar[5]arene rotaxanes and establishes a robust platform for their development in chiroptical materials.