金属有机框架结构材料的负热膨胀性

Abnormal Thermal Expansion in Metal- Organic Frameworks

框架结构材料如Zr W2O8,Zr Mo2O8等,因其特有的原子排列方式往往呈现出负热膨胀性(NTE)等特殊性能。沸石和普鲁士蓝结构材料由于其特有的骨架构型,也表现出了负热膨胀性能,即体积随温度的升高而收缩。近年来,以配位化学为基础发展起来的金属有机骨架结构(Metal-Organic Frameworks,MOFs)材料正迅猛发展,新的结构不断被发现,其中不乏一些物质也表现出了负热膨胀性,如IRMOFs,HKUST-1,MIL-53等,且一些物质具有巨大的负热膨胀系数,如Ag3Co(CN)6。MOFs材料的负热膨胀性起源于其骨架中桥连原子垂直于连接方向的横向振动,而MOFs材料的热膨胀性能还涉及到配体的柔性带来的影响以及变温过程中配体的转动等行为。综述了MOFs材料的反常热膨胀性研究近年来取得的进展及展望,以期引发更多的学者对该领域的研究兴趣。

Some framework materials show unique properties due to their special atomic arrangement, among them some show negative thermal expansion, for example ZrW208 , ZrMo20s , et al, zeolite and Prussian blue analogues show neg- ative thermal expansion（ volume contracts with increasing temperature）. Recently, researches about metal-organic frameworks based on coordination chemistry developed rapidly, numerous structures have been found. Some metal-organic frameworks （MOFs） show abnormal thermal expansion, for example, IRMOFs, HKUST-1, MIL-53 show negative thermal expansion, while some MOFs show colossal thermal expansion, such as Ag3Co（CN）6. Most framework materials show negative thermal expansion due to the transverse vibration of the bridging atoms, while, as for MOFs, the flexibility and the rotation of ligands also contribute to thermal expansion properties. This paper is mainly concerning abnormal thermal expansion properties of MOFs to inspire more researchers＇ interest.