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Development of Heterogeneous Enantioselective Catalysts using Chiral Metal-Organic Frameworks (MOFs)
Published on: January 17, 2020
Solvent-modified dynamic porosity in chiral 3D kagome frameworks.
Tony D Keene1, Damien Rankine, Jack D Evans
1School of Chemistry and Physics, The University of Adelaide, SA 5005, Australia.
Dalton Transactions (Cambridge, England : 2003)
|February 21, 2013
Summary
New chiral metal-organic frameworks (MOFs) exhibit dynamic porosity and structural changes in response to solvent vapors. These MOFs show tunable thermal expansion and colorimetric responses, offering novel applications in materials science.
Area of Science:
- Materials Science
- Inorganic Chemistry
- Crystallography
Background:
- Metal-organic frameworks (MOFs) are crystalline materials with tunable porosity.
- Dynamically porous MOFs can alter their structure in response to external stimuli.
- Chiral MOFs are of interest for enantioselective applications.
Purpose of the Study:
- To synthesize and characterize novel dynamically porous MOFs with a chiral structure.
- To investigate the solvent-dependent structural and dynamic properties of these MOFs.
- To explore the potential applications of these MOFs in gas adsorption and sensing.
Main Methods:
- Synthesis of chiral MOFs using a multidentate ligand (H2diol) and Ni(II) ions.
- Gas (N2) sorption measurements at 77 K to assess porosity.
- Powder X-ray diffraction and single-crystal X-ray diffraction to determine crystal structures.
- Variable-temperature magnetometry to track structural changes.
- Thermal expansion measurements.
Main Results:
- Successfully synthesized chiral MOFs with a quartz-based structure.
- [Ni(II)(H2diol)(S)2]·xS compounds exhibit significant changes in N2 uptake upon desolvation.
- Solvent-dependent porosity was observed due to the rotation of coordinated solvent molecules.
- Reversible coordination changes in Ni(II) centers in response to H2O and MeOH vapor were detected.
- Differential thermal expansivities were observed between solvated and desolvated forms.
- Dynamic structural and colorimetric responses to adsorbates were demonstrated.
Conclusions:
- The synthesized MOFs display dynamic structural responses to guest molecules through a unique mechanism involving metal center coordination changes.
- The rotational mobility of the ligand's biaryl bond plays a crucial role in mediating these structural changes.
- These findings highlight the potential of designing MOFs with tailored dynamic properties for advanced applications.
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