Zr-based metal-organic frameworks with tailored linkers: Immobilized liquids for sorption, extraction and ionic conduction

• Applicants: Professor Dr. Peter Behrens (†); Professorin Dr. Adelheid Godt; Professor Dr. Michael Wark
• Subject Area: Inorganic Molecular Chemistry - Synthesis and Characterisation
• Term: from 2008 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 79828012

The goal is to create a liquid like phase within the pores of metal-organic frameworks (MOFs) and to use it for the transport of molecules and ions. This is based on the idea that the side chains of the organic building blocks (linkers) fill the pores and form a nanodrop of a phase which in respect to its order resembles a liquid, however, with the main difference that translation is inhibited through the anchoring at the linkers. This is why we use the term immobilised liquids. The immobilisation inhibits leakage of the liquid and microphase separation. The regular arrangement of the pores offers energetically homogeneous paths for species which are to be transported, the stiffness of the framework strongly limits swelling and shrinkage of the liquid. These properties are of significant importance for sorption, extraction and ion conduction. The MOFs with immobilised liquids will be explored in respect to these processes. Our focus will be on Zr-MOFs of the UiO and PIZOF type. The side chains will be tailored for the application: hydrophobic, hydrophilic, fluorophilic for sorption and extraction; polyether for Li+ conduction; polyether with protogenic groups for proton conduction. They will either be attached to the linkers before the synthesis of the MOF or introduced by postsynthetic modification of the MOFs.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1362: Porous Metal-Organic Frameworks