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, this work reports that an amphiphilic naphthalene-histidine compound (NIHis) readily self-assembled into distinct chiral nanostructures through pathway-dependent supramolecular polymorphism, which shows opposite and multistimuli responsive CPL signals. Specifically, NIHis display assembly-induced CPL from the polymorphic keto tautomer, which become predominant during enol-keto tautomerization shifting controlled by a bulk solvent effect. Interestingly, chiral polymorphs of nanofiber and microbelt with inverted CPL signals can 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 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 is developed. This work brings a new approach for developing smart CPL materials via supramolecular polymorphism engineering.

中文翻译：

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通过路径依赖的手性超分子多态性实现手性反转和刺激响应的圆偏振发光纳米/微米材料

超分子多晶型物的精确操控已广泛应用于控制自组装体的形态和功能，但很少用于制造具有定制特性的圆偏振发光（CPL）材料。在这里，这项工作报告说，两亲性萘-组氨酸化合物（NIHis）通过路径依赖性超分子多态性很容易自组装成不同的手性纳米结构，显示出相反的多刺激响应性 CPL 信号。具体来说，NIHis 显示来自多态酮互变异构体的组装诱导的 CPL，该 CPL 在受本体溶剂效应控制的烯醇-酮互变异构转移过程中占主导地位。有趣的是，具有反向 CPL 信号的纳米纤维和微带的手性多晶型物可以通过仅改变温度，在完全相同的溶剂组成和浓度下由相同的 NIHis 单体制备。固体微带的可调CPL性能是在研磨、酸熏和加热等多种外部物理或化学刺激下实现的。特别是，通过可逆加热-冷却协议开发了基于微带多晶型物的发射颜色和CPL开关。这项工作为通过超分子多态性工程开发智能 CPL 材料提供了一种新方法。