Direct Synthesis of a Covalent Triazine‐Based Framework from Aromatic Amides

Abstract

There have been extensive efforts to synthesize crystalline covalent triazine-based frameworks (CTFs) for practical applications and to realize their potential. The phosphorus pentoxide (P O )-catalyzed direct condensation of aromatic amide instead of aromatic nitrile to form triazine rings. P O -catalyzed condensation was applied on terephthalamide to construct a covalent triazine-based framework (pCTF-1). This approach yielded highly crystalline pCTF-1 with high specific surface area (2034.1 m g ). At low pressure, the pCTF-1 showed high CO (21.9 wt % at 273 K) and H (1.75 wt % at 77 K) uptake capacities. The direct formation of a triazine-based COF was also confirmed by model reactions, with the P O -catalyzed condensation reaction of both benzamide and benzonitrile to form 1,3,5-triphenyl-2,4,6-triazine in high yield.

Strong‐Base‐Assisted Synthesis of a Crystalline Covalent Triazine Framework with High Hydrophilicity via Benzylamine Monomer for Photocatalytic Water Splitting

“…A pore‐size analysis (Supporting Information, Figure S30b) shows the CTF‐HUST‐A1 are of microporous frameworks. Especially, the pore size of CTF‐HUST‐A1‐ t BuOK is calculated to be about 1.2 nm, matching very well with the theoretical value of CTF‐HUST‐1 . The water adsorption ability of these CTFs was also measured (Supporting Information, Figure S31).…”

“…t BuOK was found to be the best base reagent in the series, which allows one to synthesize CTF‐HUST‐A1 in high yield and less reaction time. It is noted that the method can produce CTF‐HUST‐A1‐ t BuOK in 99.2 % yield, which is much higher than previous methods (Supporting Information, Table S1) . Moreover, t BuOK is cheaper and greener than Cs 2 CO 3 used in the previous work, which makes the reaction more economic and environmental benign.…”

“…The highly robust structures deriving from an aromatic triazine linkage and fully conjugated structures enriched by aromatic nitrogen atoms of CTFs make them appealing in various applications, such as heterogeneous catalysis and photocatalysis –. As for the synthesis of CTFs, some typical synthetic methods have been reported –. However, most of the CTFs synthesized from these methods are amorphous.…”

“…The polycondensation reaction has made the crystalline CTFs accessible at relatively mild conditions. Nevertheless, the types of the monomers for the synthesis of crystalline CTFs are still limited to nitrile, amide, aldehyde, or benzyl alcohol . The organic polymers derived from different monomers can result in the materials with different properties, which is due to the different crystallinity and peripheral residual functional groups originating from the monomers modulating the charge transport/separation and hydrophilicity of the materials .…”

Lithium‐Salt Mediated Synthesis of a Covalent Triazine Framework for Highly Stable Lithium Metal Batteries

“…Simultaneously, alternative synthetic strategies have also been developed to obtain CTFs under mild reaction conditions. These strategies include acid‐catalyzed approaches, polycondensation of aldehydes and amidines under basic conditions and P 2 O 5 ‐catalyzed conversion of aromatic amides . In particular, the utilization of elemental sulfur and aromatic nitriles to form CTFs points to the versatility of the synthetic strategies .…”