基于银硫簇的金属有机框架材料的构建及比率型荧光传感性能研究

Thiolated silver cluster with beautiful structures and exotic photophysical properties is a currently hot topic. However, low quantum yield and notorious instability considerably hampered their extensive applications. Cluster-based metal-organic frameworks (MOFs) with porosity, rigidity and stability have demonstrated promising application in separation, adsorption, catalyisis, luminescent material etc. Therefore, cluster-based MOFs provide an adaptable platform for thiolated silver clusters to retain or enhance luminescence, overcome instability and extend application. This project will assemble thiolated silver clusters into MOFs using adaptable conjugated organic ligands by step-by-step and one-pot synthesis, thus, silver-thiolate-cluster MOFs with dual-emitting functionality will be designed and synthesized for the first time. By comprehensive tuning the nuclear number, configuration of silver-thiolate clusters, and/or adjusting the organic ligands' degree of conjugation, geometric configuration and substituent groups etc., this project will systemically and deeply investigate the conditions and rules of assembly, and achieve dual-emitting functionality of this new-type materials which would be applied in ratiometric luminescent sensing. This project will integrate research fileds of silver–thiolate clusters and metal-organic frameworks, which will not only enrich the categories of MOFs but also extend the application of silver–thiolate clusters. The strategy proposed in the project provides a new avenue for functional MOFs and more theoretical basis for designing high-sensitivity luminescent sensing materials.

具有优美结构和优异光物理性质的银硫簇是目前的热点研究领域，但低量子产率和不稳定性阻碍其广泛应用。多孔、刚性、稳定的簇基金属有机框架（MOFs）在分离、吸附、催化、发光材料等方面显示出重大应用前景。它为银硫簇保持或增强发光性能，克服不稳定性，拓展实际应用提供了一个很好的平台。本项目将利用合适的共轭有机配体，通过分步组装和原位组装法，将银硫簇高度有序地连接成金属有机框架，首次设计合成具有双发射性能的银硫簇基MOFs材料。通过综合调节银硫簇的核数、构型或有机配体的构型、共轭程度、取代基等，系统深入地研究此类新型材料的组装条件、组装规律，实现材料的双发射性能，进而在比率型荧光传感方面得到应用。该项目的研究将实现银硫簇材料和金属有机框架材料两个研究领域的交叉融合，既丰富MOFs的种类，又拓展银硫簇的应用，为功能性MOFs的设计合成提供新思路，还为高精度荧光传感材料的设计提供更多科学理论依据。

银簇具有潜在的荧光性质，但其在室温下量子产率低，在空气中不稳定，严重阻碍了其荧光性能的开发和应用。本项目利用配位组装将银硫簇高度有序地连接成金属有机框架，同步提升了银簇的发光效率和稳定性，并开发了此类材料在荧光传感领域的应用。发表标注项目基金的SCI科研论文75篇，其中包括; Nat. Chem., 2017, 9, 689-697; Nat. Commun., 2020, 11, 3678; J. Am. Chem. Soc., 2020, 142, 12010-12014; J. Am. Chem. Soc., 2019, 141, 15755-15760; Angew. Chem. Int. Ed., 2018, 57, 12775-12779; Angew. Chem. Int. Ed., 2018, 57, 8560-8566等。组装的银簇基框架材料Ag12bpy的发光量子产率达到12.1%，并能通过荧光的快速（<1 s）开关响应，检测有机挥发物和氧气。进一步调节取代基，组装的Ag12bpy-NH2表现出蓝色荧光和黄色磷光的双重发射现象，成功实现了超快速（<0.3 s）的比率荧光氧气检测。利用吡啶配体精准修饰与桥联具有面心立方结构的Ag14超原子团簇实现其稳定性提升及温度依赖性的双发射的荧光行为。利用定点修饰和定向组装的的策略进一步推广，实现了系列银簇基材料的荧光、手性等多重功能。该项目的研究成功实现了银硫簇材料和金属有机框架材料两个研究领域的交叉融合，既丰富MOFs的种类，又拓展银硫簇的应用，为功能性MOFs的设计合成提供新思路，还为高精度荧光传感材料的设计提供更多科学理论依据。