准轮烷型预组织配体用于锕系离子的协同配位及固相分离研究

Research on novel ligands for specific identification and selective separation of actinide ions is of great significance to put forward new spent fuel reprocessing methodology in order to realize the high efficiency, high selectivity of radionuclide separation and disposal. Pseudorotaxane-type host-guest inclusion system represents a new class of supramolecular organization system, and can be expected to achieve specific identification and selective separation of actinide ions by collaborative coordination. This project intends to perform the design and syntheses of cucurbituril or crown ether host based pseudorotaxane-typed supramolecular pre-organized ligands, and utilizes a variety of comprehensive spectroscopic analysis methods to study collaborative-coordination behavior of these pseudorotaxane ligands for actinide ions with different valence states and chemial species, and finally select certain pseudorotaxane systems with specific recognition capacity of actinide ions by combining different modification methods of the host and guest molecules. Synchrotron radiation absorption spectra technology (such as EXAFS), single crystal structure analysis and theoretical calculation simulation methods will be also used to analyze the synergistic mechanism and specifici recognition for actinide ions. And meanwhile, a modification of porous silica based adsorbent by this kind of rotaxane systems will be conducted so as to figure out their performance for selective separation of actinide ions and irradiation stability of themselves. The objective of the study is to get in-depth understanding on actinide ion complexing mechanism of pseudorotaxane-typed supramolecular pre-organized system and to set up a new method for actinide ion recognition and separation based on pre-organized supramolecular system.

锕系元素选择性识别和分离用新型配体的开发，对于提出新的乏燃料后处理方法学以实现放射性核素的高效高选择性分离、处理处置具有重要的指导意义。本项目拟开展准轮烷型预组织配体用于锕系离子的协同配位及固相分离研究。首先设计合成基于葫芦脲或冠醚大环与链状吡啶嗡盐客体分子主客体包合作用的新型准轮烷配体，然后利用多种谱学综合分析手段研究这些准轮烷配体对不同价态和不同化学种态锕系离子的协同配位行为，并结合主客体分子的结构功能化修饰，筛选出具有锕系离子特异性识别能力的准轮烷体系。在此基础上，利用EXAFS等同步辐射吸收谱技术、单晶结构分析和理论计算模拟的方法分析其协同配位和特异性识别机理。最后将这一类准轮烷体系修饰到多孔硅基吸附剂上，研究其对锕系离子的选择性分离性能及材料自身辐照稳定性。本项目的研究，将促进对准轮烷与锕系离子协同配位机制的认识，并推动基于超分子预组织体系的锕系离子识别和分离新方法的发展。

锕系元素选择性识别和分离用新型配体的开发，对于提出新的乏燃料后处理方法学以实现放射性核素的高效高选择性分离、处理处置具有重要的指导意义。本项目围绕“准轮烷型预组织配体对锕系离子的协同配位化学研究及固相核素分离应用”这一总体科学目标，开展了基于葫芦脲或冠醚大环的超分子准轮烷配体的设计合成、准轮烷配体对锕系离子的协同配位识别机理分析和准轮烷配体的结构修饰及其固相分离锕系离子的研究三个方面的研究。在四年的研究过程，以葫芦脲和冠醚作为大环包合分子设计合成了系列基于吡啶甲酸骨架和联吡啶骨架的准轮烷配体，发现主客体的几何形状和尺寸匹配效应在构建协同配位超分子体系时具有非常重要的作用，并从其中筛选出四种具有协同识别锕系离子能力的准轮烷；系统研究了具有协同识别能力的CB7基吡啶甲酸骨架准轮烷配体与锕系离子的配位化学行为，结合多种表征手段分析了其协同配位机理，特别是超分子配体所特有的结构柔性和自适应性；利用筛选的具有良好协同配位能力的准轮烷配体初步开展了核素分离应用研究，展现了良好的应用前景。基于本项目研究成果，提出并发展了新型锕系准轮烷配体，并评估了具有良好协同配体能力的准轮烷配体的核素分离性能，为此类配体的未来应用潜力提供了关键数据支持和技术积累。本项目的研究结果累计发表SCI论文15篇，包括Nature Communications, Journal of the American Chemical Society, Angewandte Chemie International Edition, Inorganic Chemistry等知名化学期刊，并培养多名博士生和硕士生。