An understanding of crystal formation and transformation is crucial in the pharmaceutical, food, chemical, and optoelectronic industries. However, direct observation of such processes under realistic conditions in real time remains a challenge because of the lack of advanced techniques to discriminate the phase boundaries and capture the intermediate states. In this work, (Z)-1-phenyl-2-(3-phenylquinoxalin-2(1H)-ylidene)ethanone (PPQE) with crystallization-induced emission properties was reported. Three polymorphs of PPQE with various luminescence behaviors were obtained with good reproducibility under controlled conditions and crystal transformations between two pairs of polymorphs were observed. With the crystallization-induced emission characteristics and polymorph-dependent luminescence of PPQE, we have successfully realized a real-time, on-site, nondestructive fluorescence imaging technique to monitor the crystal transformation processes, as well as crystal formation from amorphous state and dilute solution, respectively. This work provides a useful and convenient fluorescence tool for in situ crystal analysis, from which detailed experimental evidence and mechanistic insights into crystal formation and transformation can be obtained through direct fluorescence visualization.

中文翻译：

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具有结晶诱导发射特性的有机发光剂的晶体形成和转化过程的荧光可视化†

在制药，食品，化学和光电行业中，对晶体形成和转化的理解至关重要。但是，由于缺乏区分相界和捕获中间状态的先进技术，在现实条件下实时实时观察这些过程仍然是一个挑战。在这项工作中，（Z）-1-苯基-2-（3-苯基喹喔啉-2（1 H报道了具有结晶诱导的发射特性的）-亚丙基）乙酮（PPQE）。在受控条件下，获得了三种具有不同发光行为的PPQE多态性，并具有良好的重现性，并观察到两对多态性之间的晶体转变。借助PPQE的结晶诱导发射特性和依赖于多晶型物的发光，我们成功地实现了实时，现场，无损的荧光成像技术，可监控晶体的转化过程以及由非晶态和稀溶液形成的晶体， 分别。这项工作为原位提供了一个有用且方便的荧光工具 晶体分析，可通过直接荧光可视化从晶体分析中获得详细的实验证据以及对晶体形成和转化的机理见解。