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Author Spotlight: Functionalizing Metal-Organic Frameworks: Advancements, Challenges, and the Power of Post-Synthetic Ligand Exchange
Published on: June 23, 2023
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Systematic Study on Zirconium Chelidamates: From a Molecular Complex to a M-HOF and a MOF
Mirjam P M Poschmann1, Özge Alan1, Sho Ito2
1Institute of Inorganic Chemistry, Christian-Albrechts-University Kiel, Max-Eyth-Street 2, 24118 Kiel, Germany.
Inorganic Chemistry
|June 29, 2023
Summary
This study synthesizes and characterizes three novel zirconium chelidamates, including a porous metal-containing hydrogen-bonded organic framework and a unique zirconium metal-organic framework. These compounds exhibit stability and selective porosity, with potential applications in gas storage and separation.
Area of Science:
- Coordination Chemistry
- Materials Science
- Supramolecular Chemistry
Background:
- Zirconium-based materials are of interest for their diverse structural possibilities and applications.
- Chelidamic acid is a versatile ligand capable of forming various coordination complexes.
- Developing porous materials with tunable properties remains a key challenge in materials science.
Purpose of the Study:
- To synthesize and characterize novel zirconium chelidamate complexes.
- To investigate the structural diversity and properties of these compounds, including porosity and stability.
- To explore the potential of these materials in gas adsorption and separation.
Main Methods:
- High-throughput synthesis and characterization of zirconium chelidamates using chelidamic acid.
- Single-crystal X-ray diffraction and powder X-ray diffraction (PXRD) for structural elucidation.
- Single-crystal 3D electron diffraction and Rietveld refinements for challenging structures.
- Gas (N2, CO2) and water adsorption isotherms to determine porosity and surface area (BET).
Main Results:
- Successful synthesis of three crystalline zirconium chelidamates: a molecular complex (1), a porous M-HOF (2), and a Zr-MOF (3) with a rare mononuclear IBU.
- Chelidamate ions act as palindromic pincer ligands, with additional aryloxy coordination in compound 3.
- Compound 2 exhibits flexible, water-porous behavior, while compound 3 shows porosity towards N2, CO2, and various solvents, with a BET surface area of 410 m2/g.
- All compounds demonstrate stability in organic solvents and thermal stability above 280 °C.
Conclusions:
- The study successfully produced diverse zirconium chelidamate structures with distinct properties.
- Compound 3 represents a novel Zr-MOF with a unique building unit and significant porosity for gas adsorption.
- These materials show promise for applications requiring selective adsorption and separation due to their tunable porosity and stability.
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