Direct synthesis of amorphous metal-organic frameworks from nanoclusters

Area of Science:

• Materials Science
• Nanotechnology
• Chemistry

Background:

• Direct synthesis of amorphous metal-organic frameworks (aMOFs) is challenging due to unpredictable network formation.
• Traditional methods involve crystallizing then amorphizing, which is inefficient.

Purpose of the Study:

• To develop a controlled direct synthesis strategy for aMOFs using pre-formed nanoclusters and rigid linkers.
• To establish design principles for aMOF formation and control over disorder and defect chemistry.

Main Methods:

• Synthesis of aMOFs using pre-formed nanoclusters and rigid organic linkers.
• Kinetic control via fast reactions under basic conditions at room temperature.
• Characterization using X-ray pair distribution function, thermogravimetric analysis, and statistical analysis.
• Tuning metal composition through doping with inert cations.

Main Results:

• The nanocluster approach provides enhanced control over amorphous network formation, disorder, and defects.
• Fast reactions under basic conditions at room temperature suppress crystallization, favoring amorphous structures.
• Doping with inert cations increases defect density and structural disorder.
• aMOFs exhibit unique structural motifs not directly mappable to crystalline polymorphs.

Conclusions:

• A systematic strategy for direct aMOF synthesis using nanoclusters has been established.
• Kinetic control and metal composition tuning are key factors in designing aMOF disorder.
• This work lays the groundwork for tailoring aMOFs for advanced applications in catalysis, adsorption, and transport.