外部重原子效应增强分子室温磷光的作用机理与规律研究

Given that external heavy-atom effect can balance the relationships among fluorescence quantum yield, phosphorescence quantum yield and phosphorescence lifetime effectively, it has become one of the most important strategies to optimize luminescence performances. However, studies on external heavy-atom effect are still in the stage of phenomenology and the lack of its mechanism research, to a large extent, limits the usage of external heavy-atom effect to design different molecular systems to meet the practical applications.. In the present project, we will study the mechanism and rules for external heavy-atom effect enhanced molecular room-temperature phosphorescence systematically from the view of orbital match and hybridization through a delicate molecular structure design, combining different important techniques, including transient absorption spectra, single crystal X-ray diffraction and density functional theory calculations. The contributions of various types of molecular orbital interactions involved will be clarified and the mechanism model will be improved to provide general principles for molecule design. Furthermore, the preliminary applications of external heavy atom effect in oxygen sensing and cell imaging will be explored. This project will not only help to gain a deeper understanding and controllable utilization of external heavy atom effect, but also promote its practical applications in the related fields.

外部重原子效应可有效平衡荧光量子产率、磷光量子产率与磷光寿命之间的关系，已经逐渐成为优化体系发光性能的重要手段。但其研究主要处于现象学阶段，缺乏深入的机理研究，这大大限制了有效利用外部重原子效应设计符合实际应用需求的体系。. 本申请项目拟从轨道匹配杂化出发，通过精细的分子结构设计，结合瞬态吸收光谱、单晶X射线衍射及密度泛函理论计算等重要技术手段，对外部重原子效应加强分子室温磷光的作用方式及作用规律进行系统研究；明确不同分子结构中存在的各种分子轨道作用类型对外部重原子效应的贡献，完善机理模型，以期提供具有普适性的分子设计原则；同时拟初步探究外部重原子效应在氧气传感及细胞成像方面的应用。该工作的开展不仅有助于更加深入理解且可控应用外部重原子效应，也将进一步推动其在相关领域的实际应用。

相比于传统成像及检测方法，荧光分析法因其高灵敏性、非侵入性以及直观实时性等优点受到广泛关注。本项目基于荧光分析法，成功设计并合成了一系列具有分子内电荷转移性质的7-氨基喹啉类荧光染料，探究了其基本的荧光性质，并进一步研究了这些喹啉类荧光染料在细胞成像方面的应用。实验结果显示所合成的喹啉染料对细胞内高尔基体细胞器具有特异性识别的性质，这对开发针对高尔基体的基于喹啉类染料的载药体系奠定了相应的基础。同时还构筑了具有双荧光发射性质的复合材料，利用其优异的双发射性质实现了水体污染物萘普生、氟离子及铝离子的痕量检测，这对水体污染的实时监控和治理起到了推动作用。