金属有机框架材料中聚集诱导发光性质的引入及对VOCs的传感应用研究

Current and intensive research on metal-organic frameworks (MOFs) have revealed the interesting and useful porosity-related functionality of these crystalline solids, which offer a unique platform for the development of solid-state luminescent materials, thus making them highly promising for utilization in chemical sensors, light-emitting devices, and biomedicine. However, the narrow choices of luminogenic building units and the low quantum yield make the design of luminescent MOFs still a big challenge. Development of new strategy for the new type of MOFs materials with enhanced luminescence and performance is highly desirable. Recently, molecules with aggregation-induced emission (AIE) characteristics have been developed and drawn much attention, due to their exotic turn-on emission nature in aggregate form or solid-state. In this project, inspired from AIE phenomenon, we will utilize AIE type chromophores as building units to construct AIE-based luminescent MOFs (AIE-MOFs) with sustainable porosity. By using elaborately designed AIE ligands and tuning experimental parameters, not only the structures and pore properties of AIE-MOFs,but also the luminescence can be systematically tailored. In AIE-MOFs, coordinative immobilization of functionalized AIE core within rigid porous matrix, and AIE effect from molecular packing between AIE ligands or AIE ligands-guest, both could turn on fluorescence in the typically non-emissive manner. In addition, the combination of luminescence and accessible porosity within such materials imparts them with the capability of transducing the host-guest chemistry to detectable changes in their luminescence and makes them promising candidates for chemical sensing applications. AIE-MOFs or MOFs functionalized with AIE luminogens serving as a fluorescent sensor for the detection of adsorbed analytes, e.g. VOCs,explosives, will be preliminarily investigated in this research. The AIE-MOFs will offer a platform for scientists to look into light emissions from matrix coordination induced emission or luminogenic aggregates, from which information on structure-property relationships and insights into mechanisms may be gained. Such information will be instructive to the structural design for the development of new type of highly-efficient luminescent MOFs materials, and also promote their potential utility toward sensing and detection.

本项目旨在将聚集诱导发光（AIE）的原理方法与金属有机框架结构（MOFs）的设计相结合，在充分利用金属有机框架材料结构与性质可调性的基础上，将功能无机组分与具有AIE性质的新型配体组装系列基于聚集诱导发光性质的新型金属有机框架功能发光材料（AIE-MOFs）。通过系统研究这一新型材料"构造单元-框架结构-发光性能"之间的关系，探索其荧光产生机理及结构、性质对荧光性能的影响机制，为在设计中实现材料结构与发光性能的可操控性提供依据。同时将AIE-MOFs特殊的孔道结构及独特的AIE发光性质相结合，充分利用主客体分子间在空间和能量上的加合与协同等多重识别作用，开发针对特定VOCs和爆炸物分子的高效荧光传感体系。本项目的研究将为设计新型高效金属有机框架发光材料提供新的思路，进一步丰富MOFs荧光的多样性，并推进其在荧光传感方向上的应用研究。

本项目将聚集诱导发光（AIE）的原理方法与金属有机框架结构（MOFs）的设计相结合，设计了系列基于四苯乙烯、四苯丁二烯、芴基以及蒽醌衍生物且具有较强AIE发光性质的多羧基有机配体，在充分利用金属有机框架材料结构与性质可调性的基础上，通过自组装的方式将这些AIE配体与Zn（II），Zr（IV）和镧系金属离子或金属簇组装成系列结构新颖，性能优异的新型金属有机框架功能发光材料（AIE-MOFs），并成功将聚集诱导发光性质引入至MOF体系中。本项目较为系统研究了AIE-MOF体系这一新型材料"构造单元-框架结构-发光性能"之间的关系，以及荧光产生机理及结构、性质对荧光性能的影响机制；利用其独特的AIE发光性质，以及主客体分子间在空间和能量上的加合与协同等多重识别作用，在水体系实现了对爆炸物分子2,4,6-三硝基苯酚（TNP）以及Al（III）等的高效荧光识别；同时对基于螺二芴的手性MOF材料的二阶和三阶非线性光学性质进行了较为深入的研究。