Mechanochemical Cyclotrimerization: A Versatile Tool to Covalent Organic Frameworks with Tunable Stacking Mode

Abstract

We introduce the first mechanochemical cyclotrimerization of nitriles, a facile strategy for synthesizing triazine‐containing molecules and materials, overcoming challenges related to carbonization and solubility. Conducting this solid‐state approach in a mixer ball mill with 4‐Methylbenzonitrile, we synthesize Tris(4‐methylphenyl)‐1,3,5‐triazine quantitatively in as little as 90 minutes. Just as fast, this mechanochemical method facilitates the synthesis of the covalent triazine framework CTF‐1 using 1,4 Dicyanobenzene. Material characterization confirms its porous (650m²g‐1) and crystalline nature. Adjusting the induced mechanical energy allows control over the obtained stacking conformation of the resulting CTFs ‐ from a staggered AB arrangement to an eclipsed AA stacking conformation. Finally, a substrate scope demonstrates the versatility of this approach, successfully yielding various CTFs.