Linkage Multi-functionalization in Covalent Organic Frameworks via Criss-Cross 1,3-Dipolar Cycloaddition

Area of Science:

• Materials Science
• Polymer Chemistry
• Organic Chemistry

Background:

• Functionalization of covalent organic frameworks (COFs) is crucial for tailoring their properties and applications.
• Multi-functionalization strategies for polymers, especially COFs, are underdeveloped, limiting their potential.
• Azine-linked COFs offer a platform for post-synthetic modification.

Purpose of the Study:

• To develop a novel and general strategy for simultaneous multi-functionalization of azine-linked COFs.
• To demonstrate the versatility of the strategy in introducing diverse functional groups into COFs.
• To enable the creation of highly functionalized COFs for advanced applications.

Main Methods:

• Utilizing a criss-cross 1,3-dipolar cycloaddition reaction between azine linkages in COFs and multifarious alkynes.
• Employing alkynes with different functional groups to achieve simultaneous homo-type and hetero-type functionalization.
• Synthesizing and characterizing over 10 different functionalized COFs.

Main Results:

• Successfully demonstrated a novel linkage conversion strategy for COF functionalization.
• Achieved simultaneous introduction of multiple, diverse functional groups into azine-linked COFs.
• Constructed more than 10 distinct functionalized COFs, showcasing the method's broad applicability and high efficiency.

Conclusions:

• The developed strategy provides a powerful and general tool for dense functional group introduction into COFs.
• This method significantly expands the possibilities for designing COFs with specific properties.
• The functionalized COFs are poised for further exploration in various application domains.