Synthesis of Acid-Base-Resistant 3D MOF-Network with Ligand Containing a Concave Backbone and Convex Binding Sites

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Crystallography

Background:

• Designing functional organic ligands is key for constructing advanced porous materials.
• Tailoring ligand geometry influences the self-assembly of metal-organic frameworks (MOFs).

Purpose of the Study:

• To introduce a novel ligand design featuring a concave backbone and convex binding sites.
• To explore the formation of extended frameworks using this new ligand.
• To investigate the role of the metal ion in dictating the framework topology.

Main Methods:

• Synthesis of a C2-linked 1,2,3-trisubstituted arene ligand with meta-COOH side arms.
• Crystallization with different metal ions (Co2+, Cd2+) to form extended structures.
• Characterization of the resulting metal-organic frameworks (MOFs).

Main Results:

• The ligand successfully formed extended frameworks with different metal ions.
• Cobalt(II) ions yielded a 1D linear polymer.
• Cadmium(II) ions resulted in 3D porous networks with a novel (3,3-c) topology.
• The synthesized MOF demonstrated exceptional stability across a wide pH range (2-11).

Conclusions:

• The new ligand design is effective for creating diverse MOF structures.
• The choice of metal ion significantly impacts the dimensionality and topology of the resulting frameworks.
• The high stability of the MOF in aqueous conditions suggests promising applications in solution-based processes.