富功能识别位和框架动态性MOFs荧光材料的构筑及传感性能

MOFs-based fluorescent sensing materials have attracted great attention because of their unique pore structures, tunable fluorescence and high framework flexibility. How to improve the sensitivity and selectivity of fluorescent sensing is the key problem in the design and construction of such materials. The research program is intended to synthesize fluorescent MOFs with lewis basic sites by adopting carboxylate ligands pre-functionalized with -NH2, -CONH2 and -OH group, and fluorescent MOFs with lewis acidic sites can be prepared by post-synthesized modification strategy or template effect of porphyrin derivative bifunctional ligands featuring central porphyrin ring grafted with peripheral pyridyl, phenyl carboxylate, imidazolyl, or polynitrogen heterocycle coordination group. Structurally dynamic “soft” MOFs with large-sized channel and high framework flexibility can be synthesized through combined effect of both ligand isoreticular expansion and host-guest induced interaction of structure direct agent. Strong recognition ability of lewis acid base sites and π-electron wall along with highly structural dynamic of flexible framework for fluorescent MOFs materials are responsible for the efficient improvement of selectivity and sensitivity of fluorescent sensing. The operated application performance can be improved by micro-nanostructure preparation and thin film fabrication of MOFs fluorescent sensing materials to control granularity and morphology. The MOFs with strong guest-acessable receptors are expected to have greater potential in qualitative analysis and quantitative detection of the targeted analyte in various environment and medium; and “soft” MOFs with dynamic structures can serve as remote sensing of temperature, pressure, radiation, electricity, and magnetism, etc. Through this research program we can preliminarily realize the controllable assembly of MOFs fluorescence chemosensor, reveal structure-function relationship of their sensing performance, as well as establish sensing model and interpret sensing mechanism in MOFs system. The research results will provide theoretical basis and technical support for the design of new fluorescence sensors with high sensitivity, high selectivity, and good practical maneuverability for the analysis and detection of trace substances in the environment and medium.

MOFs荧光传感材料因具有独特的孔结构、荧光可调性和框架柔性等特点，已成为该领域的研究热点之一。而如何提高传感选择性和灵敏度已成为其构筑瓶颈。拟以-NH2、-CONH2和-OH等预功能化的配体组装Lewis碱特征MOFs，以吡啶基、苯羧基、多氮唑基等修饰的卟啉衍生物模板合成和后功能化制备Lewis酸特征MOFs，以同形配体和结构导向剂控制“软”MOFs组装。利用Lewis酸碱位、π电子墙的强识别能力和“软”框架的动态性，以提高传感的选择性和灵敏度；利用微纳米化和成膜控制材料粒度和形貌，以提高其使用操控性；研究强识别位材料对环境和介质的分析检测能力及“软”材料对温度、压力、辐射、电场、磁场的传感作用，揭示MOFs荧光传感的构效关系，初步实现MOFs传感材料的可控组装；建立MOFs荧光传感模型、诠释传感机制。研究结果将为设计高选择性、高灵敏度和高操控性能的新型荧光传感器提供理论基础和技术支撑。

荧光型金属有机框架材料（MOFs）具有比表面积大、孔隙率高、结构可裁剪性强、发光性能优异等特点，为探索主-客体作用中所涉及的物理和化学过程提供了理想的研究平台。特别是此类材料具有较强的客体敏感的荧光调变能力、高效的微孔分离和富集能力以及结构动态性发光能力，能够显著提高荧光传感的选择性和灵敏度，以实现复杂组分体系的快速痕量分析与检测，以及特殊环境的遥感、遥测。本项目主要围绕MOFs材料的可控组装、光吸收与光发射、荧光传感，以及传感机理等方面进行了系统研究。设计合成了富Lewis酸碱位、π-电子墙等富功能识别位的MOFs荧光材料和结构动态的MOFs荧光材料，初步实现了对特定对象（如分子、离子）的定性分析/定量检测和特定物理参数（如温度、压力、pH值等）的荧光传感，同时对所合成MOFs材料实施荧光传感过程的内在机制进行了探索。通过项目研究获得了4种MOFs荧光传感材料，初步实现了对Ag+、Pd2+和Fe3+金属离子的定量分析和定量检测，以及小分子的荧光传感，有望应用于污水中重金属离子的快速分析与检测。原位掺杂制备了1种三重态的近白光发射的稀土MOFs白光材料（HoTZI: Tb3+, Sm3+），可用于新型荧光粉的制作。制备了1种快速、高效的吸水剂，可用于水泥的快速硬化、特殊环境的除潮和除湿作用等领域。结合实验模型，借鉴分子体系中荧光传感的主-客体识别原理，明晰了MOFs材料中荧光传感的构效关系，为MOFs材料的可控组装和高性能荧光传感器的设计提供了一定的实验依据和理论支撑。