Reticular Synthesis of Multinary Covalent Organic Frameworks

Area of Science:

• Materials Science
• Chemistry
• Nanotechnology

Background:

• Covalent organic frameworks (COFs) are crystalline porous polymers.
• Existing 2D COF topologies are relatively simple.
• Developing COFs with complex topologies is challenging.

Purpose of the Study:

• To synthesize and characterize a novel 2D porous covalent organic framework (COF-346) with an unprecedented tth topology.
• To explore the structural complexity and potential of COFs with intricate network architectures.
• To report additional COFs with rare or defected topologies.

Main Methods:

• Utilized hexaminophenyl benzene, tetrakis(4-aminophenyl) ethane, and 1,3,5-tris(p-formylphenyl)benzene as building blocks.
• Employed imine linkages for framework construction.
• Leveraged precise linker geometry, metrics, and dynamic imine formation for successful crystallization.

Main Results:

• Successfully synthesized COF-346, a 2D porous covalent organic framework with a novel tth topology.
• COF-346 exhibits a higher degree of structural complexity with three types of vertices and edges, and three types of linkers.
• Reported COF-360 with a rare kgd topology and COF-340, the first crystalline porous COF with a defected tth topology.

Conclusions:

• The precise design of linkers and dynamic imine chemistry are crucial for constructing complex COF architectures.
• COF-346 represents a significant advancement in COF structural diversity and complexity.
• The reported COFs expand the library of known topologies and provide platforms for further materials development.