Department of Chemistry The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong 999077 China.
Hong Kong Branch of Chinese National Engineering. Research Center for Tissue Restoration and Reconstruction Institute for Advanced Study Department of Chemical and Biological Engineering The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong 999077 China.
Adv Sci (Weinh). 2021 Feb 11;8(7):2004299. doi: 10.1002/advs.202004299. eCollection 2021 Apr.
The study of nonconventional luminescence is important for revealing the luminescence of natural systems and has gradually drawn the attention of researchers in recent years. However, the underlying mechanism is still inexplicable. Herein, the luminescence behavior of two series of simple, heteroatom-containing small molecules without aromatic rings, i.e., maleimide and succinimide derivatives, are studied to gain further mechanistic insight into the nonconventional luminescence process. It has been unveiled that all the molecules exhibit bright and visible luminescence in concentrated solution and solid state and the formation of clusters is the root cause for such behaviors, which can effectively increase the possibility of both the nonradiative n-* and favorable -* transitions and stabilize the excitons formed in the excited state. The distinctive luminescent phenomena and intriguing mechanism presented in this work will be significant for understanding the mechanism of clusteroluminescence and provide new strategies for the rational design of novel luminescent materials.
非传统发光的研究对于揭示自然体系的发光行为具有重要意义，近年来逐渐引起了研究人员的关注。然而，其内在机制尚无法解释。在此，我们研究了两个系列的简单、含杂原子且不含芳环的小分子（即马来酰亚胺和琥珀酰亚胺衍生物）的发光行为，以深入了解非传统发光过程的机制。研究结果表明，所有分子在浓溶液和固态中均表现出明亮的可见光发射，而团簇的形成是导致这种行为的根本原因，它可以有效增加非辐射 n-* 和有利 -* 跃迁的可能性，并稳定激发态中形成的激子。本工作中呈现出的独特发光现象和有趣的机制对于理解团簇发光的机制具有重要意义，并为新型发光材料的合理设计提供了新的策略。
