多孔金属-有机框架多层次后合成修饰及相应物化性能变化研究

Post synthetic modifications (PSM) of Microporous Metal-Organic Frameworks (MMOF) concering the special functional group is a new level of function modification research. This project aims at the construction of MMOFs with tag group (such as hydroxyl, halogen, cyanogroup, heterocycle, et al) maintained in the channel and conducting PSM study including covalent PSM, dative PSM and post-synthetic deprotection based on the organic reaction character of the tag group and finding new types of PSM. Tandem PSM including at least two steps will be explored concerning those MMOFs which possess high stability and tag group with rich organic reaction possibility. Through the appling of different characterization techniques including NMR, MS and especially flsorescence and UV-Vis spectrum and introducing of small molecular guest probe such as solvent, gas as well as iodine, a new way to monitor and track the PSM modification process will be established, the modification effect of different PSM routes and reaction conversion on whole or part of the skeleton, on the wall, windows of the channels and on the configuration of tag group. Some typical examples which contributed to explain the modification of PSM on gate-opening, hydrophilic or hydrophobic properties and small molecular recognition will be explored. The multiple modified effects of physical/chemical properties caused by PSM will be emphasized so as to clarify relative reaction activity, charge-transfer, spatial effect and cooperative host-guest interaction.

针对多孔金属-有机框架（MMOFs）中特定官能团后合成修饰是一种新层次上的功能调控研究。本项目拟定向构筑孔道内部含有羟基、卤素、氰基、杂环等潜在活性官能团的MMOFs，依照孔道内上述自由官能团的化学特点，进行共价、配位以及去保护等各类后合成修饰研究；发掘新类型后反应。针对稳定性高、官能团化学调变性丰富的特殊体系，探寻新颖串联后反应的有效路线。选择不同特性的客体分子为探针，结合核磁、质谱、尤其是荧光、紫外可见光谱等技术建立反应过程的有效监测及跟踪方法；探讨不同后合成修饰路线和反应程度对于特定体系骨架整体和局部，以及孔壁类型、孔道窗口、孔道内官能团排布等的多级调控作用；为可控开门效应、亲憎水调变、分子识别控释等调控作用提供实例。综合研究后修饰对目标物相应物化性能的多层次影响与效应关系，进而尝试阐明其化学反应性、电荷转移、空间效应，尤其是协同调控等核心特征。

项目围绕MOFs定向构筑及可控合成，开发新型MOFs后合成修饰体系及反应路线，建立跟踪及评估后合成修饰过程和效应新方法，阐析修饰体系构效关系等内容展开研究。主要进展包括：1）定向构筑系列稳定性高、孔穴率大、官能团化学调变性丰富的簇基、柱-层、柱链MOFs体系；2）基于MOFs结构特点，建立了水诱导配位畸变、后合成氧化、后合成金属离子替换、后合成热消除等新颖后合成反应方法；3）发展了综合利用核磁、质谱、粉末衍射、荧光、紫外可见光谱、ICP发射光谱、磁、吸附等技术监测及跟踪方法后反应过程的方法；4）通过串联后合成修饰，首次实现MOFs四重磁基态调控，通过热消除在MOFs体系引入稳定自由基，通过后合成离子替换显著增强高孔穴率MOFs框架稳定性，通过后合成氧化实现荧光调控；5）以后合成修饰为基础，拓展至MOFs的成型加工，发现了系列具有玻璃态转变能力的新类别MOFs体系；6）针对后修饰产物，尝试阐析了其结构、化学反应性、电荷转移、空间效应，尤其是协同调控等核心特征与其物化性能间的效应关系。目前发表SCI收录论文15篇，其中包括国际重要化学期刊J. Am. Chem. Soc.1篇、Angew. Chem. Int. Ed.1篇Coord. Chem. Rev.1篇、Chem. Sci.2篇、Chem. Eur. J. 2篇，Inorg. Chem. 3篇。