Increasing the complexity in breathing metal-organic frameworks using organic building units with conformational flexibility

• Applicant: Dr. Helge Reinsch
• Subject Area: Solid State and Surface Chemistry, Material Synthesis
• Term: from 2017 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 362562990

This project aims at the synthesis of new metal-organic frameworks (MOFs) incorporating intrinsically flexible organic building units. Therefore the obtained framework compounds are expected to exhibit reversible structural changes. The organic building units best suited for this purpose are alkanedioic acids and their functionalised derivatives, partially aliphatic dicarboxylic acids which also contain an aromatic benzene core and ferrocenedicarboxylic acid. The most important structural characterisation method will be X-ray powder diffraction. While the discovery of new compounds is anticipated, it is also expected that aliphatic analogues of well-known MOFs based on rigid linker molecules will be obtained. In this case the influence of the flexible unit on the compounds properties can be directly deduced by comparison to its rigid counterpart. Thus the flexibility of the investigated compounds depending on external stimuli like pressure, temperature and guest molecules will be also investigated by means of X-ray powder diffraction. The expected structural flexibility of the new MOFs will be compared to related compounds based on rigid organic building units. Pressure dependent diffraction experiments will be conducted using synchrotron radiation and a diamond anvil cell. In addition the phase transitions upon adsorption of guest molecules from solution and especially their kinetics will be investigated in-situ using synchrotron radiation.

• DFG Programme: Research Grants
• International Connection: Belgium, France
• Cooperation Partners: Professor Rob Ameloot, Ph.D.; Dr. Alexandra Lieb; Professor Dr. Guillaume Maurin