Handedness‐Inverted and Stimuli‐Responsive Circularly Polarized Luminescent Nano/Micro‐Materials through Pathway‐Dependent Chiral Supramolecular Polymorphism

Abstract The precise manipulation of supramolecular polymorphs has been widely applied to control the morphologies and functions of self‐assemblies, but is rarely utilized for the fabrication of circularly polarized luminescence (CPL) materials with tailored properties. Here, we report that an amphiphilic naphthalene‐histidine compound (NIHis) readily self‐assembled into distinct chiral nanostructures through pathway‐dependent supramolecular polymorphism, which showed opposite and multi‐stimuli responsive CPL signals. Specifically, NIHis displayed assembly‐induced CPL from the polymorphic keto tautomer, which became predominant during enol‐keto tautomerization shifting controlled by a bulk solvent effect. Interestingly, chiral polymorphs of nanofiber and microbelt with inverted CPL signals could be prepared from the same NIHis monomer in exactly the same solvent compositions and concentrations by only changing the temperature. The tunable CPL performance of the solid microbelts is realized under multi external physical or chemical external stimuli including grinding, acid fuming and heating. In particular, an emission color and CPL on‐off switch based on the microbelt polymorph by reversible heating‐cooling protocol was developed. This work brings a new approach for developing smart CPL materials via supramolecular polymorphism engineering. This article is protected by copyright. All rights reserved