结晶诱导室温单组分有机长余辉发光材料的设计合成、发光性能及机理

Organic materials with room-temperature persistent phosphorescence are emerging materials which break the traditional concept of only inorganic materials exhibit persistent phosphorescence at room-temperature. Such new materials attract considerable attentions because they not only can fill in gaps of the inorganic persistent phosphorescent materials but also could provide new kind of persistent phosphorescent materials with high performance, especially smart responsive. They also reveal a totally new approach for tuning the excited state of organic materials, which is very important for the understanding in depth of the luminescent behavior of organic materials. In this project, based on our previously discovery of some organic persistent phosphorescent materials, we propose to synthesize a series organic materials with new design molecular structures and crystallization-induced persistent phosphorescence of their crystals. Then the relationship of molecular structures, crystal structures and their properties of both persistent luminescence and mechano-responsive will be investigated in detail, which can be used to verify our proposed “intermolecular electronic coupling” mechanism. We will focus on studying the molecular design strategy, and the mechanism of their persistent phosphorescence and mechano-responsive properties, in order to reveal the tuning approach of the excited state life in organic materials with persistent phosphorescence. The work being proposed in this project will push forward the development of those new organic functional materials with persistent phosphorescence. Furthermore, it will promote the fundamental investigation on luminescent behavior and excited state feature of organic molecules as well.

室温有机长余辉发光材料是一类刚刚兴起的新材料，打破了长余辉发光局限于无机材料的传统观念，受到了人们高度重视。这类新材料不但能填补现有长余辉材料的短板，而且为发展高性能，特别是智能响应性的长余辉材料提供了新的材料基础。并且为有机材料的激发态调控提供了一条全新的思路和途径，对于深入理解有机材料的发光行为具有重要的科学意义。本项目拟在前期发现一些单组分有机长余辉材料的基础上，通过分子设计合成与结晶诱导获得一系列长余辉有机晶体材料。研究分子结构、材料聚集态（晶体）结构与其长余辉及力刺激响应性能之间的联系，并验证我们提出的“分子间电子耦合作用”的解释。从而明确材料的分子结构设计策略；并且阐明其发光机理和力刺激响应机制；以及揭示有机长余辉材料激发态寿命调控的思路与途径。本项目的成功实施，不但有利于发展有机长余辉材料这一新型功能材料，还将有助于深化对有机材料分子发光行为和激发态特征等基础科学问题的认识。

有机超长磷光材料是近几年发展起来的有机发光新材料，具有裸眼可见的超长寿命磷光，也就是超长寿命的激发态，有着巨大的基础科研价值和广泛的应用前景。但是其分子结构设计策略、发光机理、激发态过程和刺激响应行为等都还不明确。本项目围绕以上问题，基于D-A型分子结构，设计合成了系列有机超长磷光分子，对该类材料的分子设计策略、发光机理和力刺激响应行为开展了详细研究。取得了以下主要成果：（1）提出了一个新的有机超长磷光分子设计策略——“柔性间隔基团”策略，并获得了高量子效率的红光有机超长磷光材料，在生物细胞成像上展现了很好的应用效果。（2）发现了有机材料力致三线态（超长磷光激子）产生现象，深入研究了其中的激发态过程。（3）提出了利用范德华力构筑“含松散区域晶体”的分子设计策略，开发了新型高灵敏“阳光再生”力刺激发光材料及器件，并应用在多彩显示、气体压力传感等，器件可重复使用超过50次。相关成果在包括化学类顶级期刊Angew Chem Int Ed（2篇）、Chem Sci （3篇）化学类顶级综述期刊Chem Soc Rev上发表标注论文9篇，其中8篇影响因子 > 6。这些论文被同行专家学者大量引用和正面评价，其中1篇选为杂志Hot论文，3篇入选ESI高被引论文，1篇入选ESI热点论文；研究论文最高SCI他引78次，综述最高SCI他引423次。此外还有一篇论文被国际学术评论网站（Wiley ChemistryViews）选为研究亮点报道。申请中国发明专利2项，获授权1项。项目负责人获得广东省杰出青年基金支助，并获评广东省特支计划科技创新青年拔尖人才；还协助培养博士研究生6名（已毕业并获得学位3名），在站博士后2名。