Encapsulating Azolates Within Cationic Metal-Organic Frameworks for High-Energy-Density Materials

Area of Science:

• Materials Science
• Inorganic Chemistry
• Crystallography

Background:

• Cationic metal-organic frameworks (CMOFs) typically use weakly coordinating inorganic anions.
• Limited diversity in CMOF counter anions restricts their potential applications.

Purpose of the Study:

• To synthesize novel CMOFs using azolates as strongly coordinating counter anions.
• To explore the potential of these new CMOFs as high-energy-density materials.
• To investigate the structural and energetic properties influenced by azolate incorporation.

Main Methods:

• Synthesis of new CMOFs with azolate counter anions.
• Characterization using X-ray diffraction.
• Quantum chemical calculations.
• Performance evaluation as energetic materials.

Main Results:

• Successful synthesis of CMOFs with azolate counter anions and ligands.
• CMOF(CuTNPO) achieved a detonation heat of 7375 kJ kg⁻¹, exceeding CL-20.
• Azolate incorporation enhanced both energy density and safety properties.
• Stronger hydrogen bonds and π-π interactions were identified as key factors for enhanced performance.

Conclusions:

• Azolates can serve as effective counter anions and ligands in CMOFs, offering strong coordination.
• This strategy significantly boosts the energy density and safety of framework materials.
• The findings open new avenues for designing advanced energetic materials based on MOFs.