Gate opening behaviour of structurally flexible porous coordination polymers - characterization by combined X-ray diffraction and sorption studies

在多孔配位聚合物（金属有机框架，mof）中，一些mof表现出所谓的门打开行为，这取决于客体分子对孔隙的负载程度。在这些结构灵活的材料中，晶体结构响应外部刺激，例如某些气体存在的差异，因此它们被认为是具有各种潜在应用前景的可切换材料。然而，到目前为止，只有少数例子是已知的，它们的结构是如何变化的。该项目的目的之一是详细调查结构变化，以了解闸门打开效应的起源和后果。为此目的，将结合吸收实验，包括纯气体和混合气体的吸收研究和突破实验，并根据在吸收研究条件下收集的x射线粉末衍射图进行结构确定研究。除此之外，改进我们实验室衍射仪的自制原位（吸收/ x射线衍射）样品支架是该项目的中心任务，以扩展研究结构柔性材料的实验可能性-独立于同步加速器束流线的访问。拟议的项目需要相关研究小组密切合作，利用他们在吸附和结构表征方面的专业知识。

Out of the class of porous coordination polymers (metal-organic frameworks, MOFs) some MOFs exhibit so-called gate opening behaviour which is dependent on the degree of loading of the pores with guest molecules. In these structurally flexible materials the crystal structure responds on external stimuli such as differences in presence of certain gases, and therefore they are regarded as promising switchable materials with various potential applications. However, up to now only for a few examples it is known, how their structures change. One aim of this project are detailed investigations of structural changes in order to understand origin and consequences of the gate opening effect. For that purpose a combination of sorption experiments, including pure and mixed gas sorption studies and break through experiments, and structure determination studies will be performed based on X-ray powder diffraction patterns collected at the conditions of the sorption studies. Besides that, it is an central task within the project, to improve the home-built in situ (sorption / X-ray diffraction) sample holder for our laboratory diffractometer in order to extend the experimental possibilities for investigation of structurally flexible materials - independent of access to synchrotron beam lines. The proposed project requires a close cooperation of the involved research groups with their individual expertise in sorption and structural characterization.