金属有机骨架材料晶体内缺陷的可控生成和功能

Defects in crystalline materials, such as dislocations, vacancies, and doping, are well-known and have been extensively studied for the impact they make on the properties of materials. However, it is not easy to control the distribution and ordering of defects in metal-organic frameworks currently. The design of defects in the materials towards specific functions is limited, and the defect structure - material property relationship needs further investigation. In this proposal, we are targeting to introduce vacancies, doping, and partial interpenetrations into the structures of the porous materials, by ligand competition, topology prescription, post-synthetic modification, as well as multi-component synthesis. This will result in the re-construction of the interfaces inside the pores. We will also explore the relationship between the properties such as porosity, chemical environment, and catalysis performance, and the structural attributes such as formation of defects, and the ordering of these defects. By addressing the following issues: the chemical insight of the vacancies formation in porous materials, the assembly mechanism of the single-phase crystalline materials from multi-component, and the relationship between the defects, and the active metal sites and pore environment; we are aiming for new materials with multi-components for multi-functions.

空缺、掺杂等晶体缺陷与材料的性质息息相关。目前，我们对缺陷在金属有机骨架材料中的分布及有序性缺乏控制，以特定功能为导向的晶体缺陷的设计相当有限，对晶体缺陷与材料性质间的构效关系需进一步阐明。本课题拟利用配体竞争、拓扑诱导、合成后修饰、多组分合成等手段将空缺、掺杂、局部穿插等晶体缺陷引入金属有机骨架材料的晶体中，实现多孔晶体材料内部界面的重构；同时将积极探索上述晶体缺陷的存在和是否有序对晶体多孔性、化学环境、催化效能等理化性质的影响，并探索晶体内部功能分区且协同的效应。在研究过程中，重点解决多孔材料内生成空缺等缺陷的化学过程、多组分参与的单相晶体组装机理、缺陷与金属活性位点及孔道性质的关联等关键科学问题，进一步拓展材料的多组分多功能。

在本项目的资助下，围绕着金属有机框架材料（MOF）内的有序缺位及基于缺位的功能化开展了具体的研究。（1）基于有序缺位，发展了新的结构精准调控方法，实现了多组分、价态可逆的官能化框架材料。将有序缺位作为MOF结构有序修饰和孔道有序调控的作用位点，基于氧缺位设计具有氧化还原活性的多孔框架材料，精准调控其催化性能。利用含缺位的金属化配体，通过拓扑分析，进一步解构MOF网络，报道了含多达五种基元的价态可逆转变的MOF结构。（2）初步研究基于组分的光学性质、光化学反应性质的MOF材料的功能化，为基于缺位化学的材料功能化奠定基础。利用镧系金属的荧光特性，研究所构筑的金属有机框架材料的荧光性能；利用含有光化学活性的配体，实现MOF内的光化学环加成反应，研究基于单晶到单晶的结构转变。发表标注受本项目资助的SCI论文13篇，其中包括3篇J. Am. Chem. Soc.、1篇Angew. Chem. Int. Ed.、1篇Coord. Chem. Rev.，发表成果获JACS Spotlights等专文报道，同时培养在项目执行期内毕业的博士研究生5名和硕士研究生3名。项目负责人在国内外会议及高校做学术报告48次。在此期间，项目负责人晋升为教授（2017年），获得上海市“青年拔尖人才”（2017年）、国家“万人计划”青年拔尖人才（2019年）等奖项，获自然科学基金委“优秀青年科学基金”支持（2019年）。