Robust mechanochromic luminescent materials are highly in demand for high-tech applications, such as mechanosensors and data recording. In this work, a new luminogen (4-(phenothiazin-10-yl)phenyl)(pyren-1-yl)methanone (Py-BP-PTZ) is synthesized and characterized, and its crystal structure and photophysical properties are investigated. Py-BP-PTZ exhibits apparent aggregation-induced emission, and polymorphism and mechanochromism properties. Two kinds of crystals with sky blue (463 nm) and green (557 nm) photoluminescence (PL), respectively, are obtained. And the sky blue PL is progressively red-shifted to orange PL (592 nm) along with the PL intensity change when the crystal is compressed under gradually strengthened external pressure. When the external pressure is released, the original sky blue PL and a new PL peak (582 nm) are recorded. Similar mechanochromic luminescence behaviors under altered external pressures are also found for the pristine solid of Py-BP-PTZ, with the PL change between sky blue (463 nm) and orange red (627 nm). In addition, the solid of Py-BP-PTZ shows reversible PL changes between sky blue (463 nm) and yellow (556 nm) by repeated grinding and solvent fuming. These interesting mechanochromic luminescence behaviors are rationalized to be caused by the changes in molecular conformations, intermolecular interactions, molecular packing patterns and aggregate morphologies. This new mechanochromic luminogen and understanding of the relevant mechanism should be useful for further development and application of new mechanochromic luminescent materials.

中文翻译：

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高对比度发光取决于AIE活性（4-（吩噻嗪-10-基）苯基）（吡喃-1-基）甲酮的多态性和机械变色

对于诸如机械传感器和数据记录之类的高科技应用，强烈需要坚固的机械致变色发光材料。在这项工作中，合成并表征了一种新型发光剂（4-（吩噻嗪-10-基）苯基）（吡喃-1-基）甲酮（Py-BP-PTZ），并研究了其晶体结构和光物理性质。Py-BP-PTZ表现出明显的聚集诱导发射，以及多态性和机械变色特性。分别获得两种具有天蓝色（463 nm）和绿色（557 nm）光致发光（PL）的晶体。当在逐渐增强的外部压力下压缩晶体时，随着PL强度的变化，天蓝色PL逐渐红移为橙色PL（592 nm）。释放外部压力后，将记录原始的天蓝色PL和新的PL峰（582 nm）。在Py-BP-PTZ的原始固体中，在改变的外部压力下也发现了类似的机械变色发光行为，其中PL在天蓝色（463 nm）和橙红色（627 nm）之间变化。另外，Py-BP-PTZ的固体通过反复研磨和溶剂发烟显示出天蓝色（463 nm）和黄色（556 nm）之间可逆的PL变化。这些有趣的机械变色发光行为被合理地认为是由分子构象，分子间相互作用，分子堆积模式和聚集体形态的变化引起的。这种新的机械致变色发光剂和相关机理的理解对于进一步开发和应用新型的机械致变色发光材料将是有用的。