Supramolecular Polymerization of Triphenylamine[3]arenes for Switchable and Stimuli‐Responsive Chiroptical Properties

The design of advanced photonic materials with integrated stimuli‐responsive properties remains coveted yet challenging. Herein, we demonstrate that chiral supramolecular assembly of triphenylamine[3]arenes (TPA[3]s) offers an efficient and modular solution to address this challenge. Despite intrinsically nonplanar and conformationally flexible macrocyclic scaffold, peripheral chiral alkyl chains direct TPA[3]s to self‐assemble into long‐range one‐dimensional (1D) nanofibers, as confirmed by transmission electron microscopy and atomic force microscopy, ultimately giving rise to intense blue circularly polarized luminescence (CPL) with a g lum of 1.2 × 10 −3 and a fluorescence quantum yield of 48%. Benefiting from the triphenylamine cores, the resulting supramolecular polymers exhibit reversible CPL switching upon acid–base stimulation. Notably, TPA[3]s readily undergo rapid photo‐induced radical generation in dilute monomeric solution, whereas this process is significantly suppressed in the supramolecular assemblies due to molecular confinement. Combining spectroscopic analyses with coarse‐grained molecular dynamics simulations reveals that the formation of air‐stable TPA radical cations disrupts the chiral packing, leading to disassembly of supramolecular polymers and the concomitant irreversible loss of CD and CPL signals. These findings establish supramolecular polymerization as a versatile strategy for organizing macrocyclic arenes into ordered 1D chiral assemblies with multi‐responsive CPL properties, while providing general design principles for photoresponsive chiral optoelectronic systems.