Carboxylate-Based Metal-Organic Framework and Coordination Polymer Glasses: Progress and Perspectives

Area of Science:

• Materials Science
• Chemistry
• Nanotechnology

Background:

• Coordination polymers (CPs) and metal-organic frameworks (MOFs) are versatile materials but suffer from poor processability and mechanical fragility in their crystalline forms.
• Zeolitic-imidazole framework (ZIF)-based glasses have shown promise, but carboxylate-based CP/MOF glasses are less developed due to strong metal-ligand bonds and low thermal stability of carboxylic acids.
• Previous methods for CP/MOF glass synthesis include desolvation and melt-quenching.

Purpose of the Study:

• To review recent advancements in the synthesis of carboxylate-based CP/MOF glasses.
• To highlight strategies for overcoming challenges in forming carboxylate-based CP/MOF glasses.
• To explore the potential applications of these novel glass materials.

Main Methods:

• Review of six studies on the synthesis of CP/MOF glasses from carboxylate-based CPs/MOFs.
• Strategies discussed include altering the metal coordination sphere and increasing ligand flexibility.
• Vitrification approaches categorized into desolvation (potentially with vapor perturbation) and melt-quenching.

Main Results:

• Successful synthesis of carboxylate-based CP/MOF glasses has been achieved through desolvation and melt-quenching.
• Aliphatic ligands were found to be more amenable to melt-quenching than aromatic carboxylates.
• The first melt-quenched carboxylate-based MOF glass was developed from an aliphatic ligand-based Mg-MOF.

Conclusions:

• Carboxylate-based CP/MOF glasses offer enhanced processability and a broad application spectrum, mirroring their crystalline counterparts.
• These glasses present opportunities for new applications, including potential use as bioactive glasses.
• Further research into modifying metal coordination and ligand freedom is key to expanding the library of carboxylate-based CP/MOF glasses.