噻吩功能化配位聚合物吸附和识别重金属离子的研究

Heavy metal ions are significant pollution for the environment due to their tremendous harms to the ecological environment and human health. How to effective removal and recognition of heavy metal ions has become an importance research topic in many disciplines. Porous coordination polymers, recognized as a new type of porous materials, exhibit many advantages such as high surface areas and porosities, modified structures and adjustable properties, and can be used to effectively absorb and rapidly recognize heavy metal ions. This project will synthesize thiophene-functionalized porous coordination polymers by adopting a series of thiophene-carboxylate bifunctional organic ligands and hard metal ions. Their frameworks and pore structures will be adjusted by varying the substituent groups, the relative position and number of carboxylate and thiophene groups, using different metal ions with diverse coordination modes, and changing the diverse experiment conditions. Moreover, on the basis of the structures of the frameworks defined by single crystal and powder X-ray diffraction, the systemic information will be acquired and the relationship between the structures and properties are summarized by studying the properties of heavy metal ions adsorption and fluorescent recognition through atomic absorption (or emission) spectroscopy and fluorescence spectrometry. This study will provide new methods for the design and synthesis of novel functional coordination polymer with large uptake capacity and selective recognition of heavy metal ions, and develop new porous materials with effective adsorption and highly sensitive recognition of heavy metal ions that can be applied for the extraction and detection of heavy metals.

重金属离子是一类重要的环境污染物，严重危害到生态环境和人类生命健康，如何有效去除和识别重金属离子已成为许多学科的重要研究课题。多孔配位聚合物作为一种新型多孔材料，具有比表面大、孔洞率高、结构可修饰、性能可调节等诸多优点，能有效吸附和快速识别重金属离子。本项目拟采用系列含噻吩与羧酸双官能团的有机桥联配体，选用硬酸金属离子，以期构筑噻吩功能化的多孔配位聚合物。通过取代基的改变、噻吩与羧酸相对位置以及数目的改变，不同配位特性的金属离子和实验条件的选择，来调控配位聚合物的结构及其孔结构。在单晶和粉末X-衍射确定其空间结构的基础上，通过原子吸收（或发射）光谱和荧光分析法来分析对重金属离子的选择性吸附与荧光识别性能，获得比较系统的信息，总结其构效关系，为定向组装高效吸附和选择性识别重金属离子功能配位聚合物提供经验和规律，开发高效吸附和高灵敏识别重金属离子的新型多孔材料，可用于重金属离子富集与检测。

多孔配位聚合物作为一种新型多孔材料，具有比表面大、孔洞率高、结构可修饰、性能可调节等诸多优点，能有效吸附和快速识别重金属离子。本项目采用含噻吩二羧酸配体、含噻吩二羧酸和双吡啶类混合配体、含噻吩二羧酸和三氮唑类混合配体与金属离子组装得到14个结构新颖的噻吩功能化配位聚合物，为定向组装功能化多孔配位聚合物提供经验和规律。利用单晶衍射、粉末衍射、红外光谱表征化合物的结构与组成，利用气体吸附测试表征了多孔性能及气体吸附性能，利用热重和XRD分析表征化合物的热稳定性，利用荧光和紫外表征了化合物荧光识别性能和染料吸附分离性能。研究发现，噻吩二羧酸配体与稀土或碱土金属构筑的配位聚合物都具有发光性能，通过荧光淬灭可用于快速识别金属Fe3+离子，且具有较好的荧光识别可循环性；由噻吩二羧酸配体构筑的锰离子配位聚合物可选择性光催化有机染料；由噻吩二羧酸配体和双吡啶类配体构筑的穿插配位聚合物具有结构柔性，在气体吸附方面表现了“开门”效应特征，且结构的柔性和气体吸附开关门压力与双吡啶配体的柔性有关；由噻吩二羧酸配体和双吡啶类配体构筑的穿插配位聚合物也具有发光性能，可用于识别金属Fe3+离子，且时间响应速度快和可循环性好；由噻吩二羧酸配体和三氮唑配体构筑的阴离子框架化合物可用于选择性吸附与分离阳离子染料。此外，稀土离子负载的噻吩功能化阴离子框架化合物可以用于荧光识别金属离子。