Synthesis and Characterization of Phenanthropyrazine‐Based Covalent Triazine Frameworks for CO ₂ Capture

In this context, two novel multi‐cyano monomers based on phenanthro‐pyrazine derivatives, dibenzo[f,h]quinoxaline‐2,3,7,10‐tetracarbonitrile (TCP) and dibenzo[a,c]phenazine‐3,11‐dicarbonitrile (TPI), were synthesized for constructing covalent triazine‐based frameworks via ZnCl 2 ‐triggered polytrimerization. The optimal molar ratios of monomers to anhydrous ZnCl 2 were first investigated, then a series of CTF‐TCPs and CTF‐TPIs were synthesized at different polymerization temperatures and characterized systematically. The resulting frameworks were amorphous and exhibited high specific surface areas (1735 m 2 g −1 for CTF‐TCP‐7 and 1400 m 2 g −1 for CTF‐TPI‐5). The CO 2 capture capacities of as‐synthesized CTF‐TCPs and CTF‐TPIs were evaluated. Owing to the presence of pyrazine and triazine rings within their highly porous structures, CTF‐TCP‐7 and CTF‐TPI‐5 demonstrated CO 2 uptake capacities of 4.10 and 3.62 mmol g −1 at 273 K. Additionally, CTF‐TCP‐3 exhibited the highest CO 2 /N 2 selectivity of 65.1 at 273 K and 1 bar as determined by the Ideal Adsorbed Solution Theory (IAST).