五唑基含能金属有机骨架的稳定化机制及组装方法研究

Energetic Metal-Organic Frameworks (MOFs) are a class of new developed energetic materials with good stability and high energy density. However, the detonation performance of current reported energetic MOFs have not outstripped the traditional energetic materials. In this program we plan to prepare several high-nitrogen to all-nitrogen energetic MOFs, based on pentazole anion and its derivatives as energetic ligand assembling with metal cation. First, the stabilization mechanism of pentazole ring and metal ion will be theoretically studied, which could provide strategies for designing energetic MOFs with reasonable structure and good balance between stability and energy. Following the strategies, the synthesized pentazole anion and its derivatives are allowed to assemble with metal cations to prepare target energetic MOFs. The prepared materials will be analyzed by X-ray difference and solid NMR and measured their sensitivity, thermal and explosive properties, with the purpose of finding the regulations between structure, stability and energy. The great number of N-N bonds with high energy in high-nitrogen and all-nitrogen ligand of energetic MOFs is expected to push the explosive performance to a higher level. Meanwhile, the coordination effect of metal cation and conjugation of framework are beneficial for the stabilization the all nitrogen ligand. It is believed that this program with potential for both academic and industrial purpose, may promote the development of future generation of energetic materials.

含能金属有机框架（Metal-Organic Frameworks，MOFs）是近年发展起来的一类稳定性好、能量密度高的新型含能材料。但与传统含能材料相比，现有含能MOFs的综合爆轰性能未有明显提升。本项目拟以全氮五唑及其高氮衍生物作为含能配体，与金属组装，构建超高氮乃至全氮含能MOFs，以期在能量水平上实现新突破。首先研究五唑环与金属的稳定化机制，设计出多种结构合理、稳定性-能量平衡的含能MOFs；基于设计的构型，将合成的五唑及衍生物与匹配的金属离子组装获得目标含能MOFs；依据X射线衍射、固体核磁等结构表征和感度、热重、爆轰性能等测试结果，探索结构-稳定性-能量之间的规律性。超高氮和全氮配体中的大量N-N高能键是含能MOFs实现能量提升的关键，而金属离子配位作用和网络状结构的共轭效应则能有效提升配体的稳定性。本项目将有力地推动新一代含能材料的开发，具重要的学术价值和应用意义。

本项目以全氮五唑及其高氮衍生物作为含能配体，与金属组装，构建超高氮乃至全氮含能MOFs，以期在能量水平上实现新突破。.首先研究了五唑环与金属的稳定化机制，设计并合成出6种结构合理、稳定性-能量平衡的含能MOFs；基于设计的构型，将合成的五唑及衍生物与匹配的非金属离子组装获得目标含能MOFs。.然后，依据X射线衍射、固体核磁等结构表征和感度、热重、爆轰性能等测试结果，探索了结构-稳定性-能量之间的规律性。超高氮和全氮配体中的大量N-N高能键是含能MOFs实现能量提升的关键，而金属离子配位作用和网络状结构的共轭效应则能有效提升配体的稳定性。.基于化合物的分子式和计算得所合成的五唑羟胺盐（NH3OH+N5-）的标准摩尔生成热为327.6 kJ/mol，采用K-J方程计算得爆速为8893 m/s，爆压为33.9 GPa，爆热为14.7 MJ/kg，由EXPLO 5计算得爆速为9005 m/s，爆压为32.7 GPa。综合来看，五唑羟胺盐理论爆轰能量达到HMX水平，爆热达3倍TNT当量。.本项目的研究成果对推动氮化学和第四代超高能含能材料的发展，具有重要的科学意义。