Transformation Strategy for Highly Crystalline Covalent Triazine Frameworks: From Staggered AB to Eclipsed AA...

Area of Science:

• Materials Science
• Organic Chemistry
• Nanotechnology

Background:

• Fabricating crystalline covalent triazine frameworks (CTFs) under mild conditions without carbonization is a significant challenge.
• Existing methods often require harsh conditions, limiting their applicability and scalability.

Purpose of the Study:

• To demonstrate a tandem transformation strategy for preparing highly crystalline CTFs.
• To achieve CTF synthesis under mild, metal-free, and solvent-free conditions.
• To explore the extension of this strategy to fluorinated CTFs with tunable properties.

Main Methods:

• A two-step process involving initial CTF-1 formation at 250 °C with superacid catalysis.
• Subsequent annealing of CTF-1 at 350 °C under nitrogen to achieve a different crystalline structure (eclipsed AA stacking).
• Adaptation of the strategy for producing crystalline fluorinated CTFs.

Main Results:

• Successfully synthesized highly crystalline CTF-1 with an eclipsed AA stacking order.
• Achieved a high surface area of 646 m² g⁻¹ for the resulting CTF.
• Demonstrated the versatility of the method for producing crystalline fluorinated CTFs with controlled fluorine content.

Conclusions:

• The tandem transformation strategy offers a mild, efficient route to highly crystalline CTFs.
• This approach facilitates the design of CTFs with tunable photoelectric properties.
• The method provides a scalable pathway for advanced materials development.