COF@COF: Constructing Core-Shell Structured Covalent-Organic Frameworks from Interpenetration Isomers.

Area of Science:

• Materials Science
• Nanotechnology
• Supramolecular Chemistry

Background:

• Core-shell structured covalent-organic frameworks (COFs) are challenging to synthesize due to inherent crystallographic differences between COF species.
• Existing methods struggle to create hierarchical COF structures with distinct core and shell components.

Purpose of the Study:

• To develop a novel strategy for constructing core-shell structured COFs using interpenetration isomers.
• To demonstrate the feasibility of this approach using the three-dimensional COF-300 framework.
• To explore the tunability of core and shell layer thicknesses in the synthesized COFs.

Main Methods:

• A two-step synthesis process was employed using identical monomers under varied reaction conditions.
• Interpenetration isomers of COF-300 were utilized to form distinct core and shell layers.
• Characterization techniques were used to confirm the core-shell structure and adjustable layer thicknesses.

Main Results:

• Successfully synthesized core-shell structured COF-300 particles, with a 5-fold interpenetrated core and a 7-fold interpenetrated shell.
• Demonstrated that the thicknesses of both the core and shell layers are adjustable.
• Validated the use of interpenetration isomers as a viable strategy for creating core-shell COFs.

Conclusions:

• A novel and effective strategy for fabricating core-shell COFs from interpenetration isomers has been established.
• This method overcomes previous limitations in synthesizing hierarchical COFs with distinct structural components.
• The developed approach offers a promising pathway for advancing hierarchical microstructures with tailored functionalities.