Beyond Solution Chemistry: Mechanochemistry Enables Clustered Defects in Metal-Organic Frameworks

Area of Science:

• Materials Science
• Chemistry
• Nanotechnology

Background:

• Defects in metal-organic frameworks (MOFs) are crucial for unique properties.
• Existing methods for defect incorporation have limitations.

Purpose of the Study:

• Introduce mechanochemistry for de novo synthesis of extrinsic MOF defects.
• Compare mechanochemical and solvothermal methods for defect incorporation.
• Investigate the formation and impact of clustered defects in MOFs.

Main Methods:

• Utilized mechanochemistry with symmetry-reduced or defective ligands.
• Synthesized MOFs using both mechanochemical and conventional solvothermal techniques.
• Systematically compared the resulting defective MOFs.

Main Results:

• Mechanochemical synthesis allows precise and rapid incorporation of defective ligands.
• Defective ligands spatially aggregate under mechanochemical conditions, forming locally missing domains.
• Clustered defects result in observable hierarchical porosity, exceeding capabilities of solution-based methods.
• Observed a unique phenomenon of cluster defects in MOFs due to uneven ligand distribution.

Conclusions:

• Mechanochemistry is a powerful tool for controlled defect engineering in MOFs.
• The formation of clustered defects leads to enhanced hierarchical porosity.
• This work establishes a new paradigm for defect control in MOF synthesis.