Linker-Guided Growth of Single-Crystal Covalent Organic Frameworks

Area of Science:

• Materials Science
• Chemistry
• Nanotechnology

Background:

• Covalent organic frameworks (COFs) are known for their crystallinity and porosity.
• Synthesizing single-crystal COFs with diverse monomers and tunable pores remains a significant challenge.

Purpose of the Study:

• To develop a method for creating complex, single-crystal COFs with mixed components.
• To demonstrate the ability to control component ratios and pore structures in COFs.
• To explore the synergistic effects of mixed components for gas adsorption and separation.

Main Methods:

• Utilized a linker-guided crystal growth strategy.
• Employed linkers that react with a node to form single-crystal COFs, guiding other linkers.
• Synthesized nine types of single-crystal COFs with up to nine components.

Main Results:

• Achieved homogeneous single-crystal COFs with controlled mixed components on the unit cell scale.
• Created COFs with structures adapting to the main component and pore volumes expanded up to 8.8%.
• Demonstrated significantly enhanced SO2 uptake (2200% and 733% increases) and high SO2/CO2 selectivity (1230-4247) in bicomponent COFs.

Conclusions:

• The linker-guided method enables the synthesis of highly complex, multi-component single-crystal COFs.
• These materials exhibit tunable porosity and remarkable synergistic performance for gas separation applications.
• The developed COFs show potential for efficient deep desulfurization of flue gas.