Covalent Triazine Frameworks Based on the First -Octahedral Hexanitrile Monomer via Nitrile Trimerization: Synthesis, Porosity, and CO Gas Sorption Properties.

Herein, we report the first synthesis of covalent triazine-based frameworks (CTFs) based on a hexanitrile monomer, namely the novel pseudo-octahedral hexanitrile 1,4-bis(tris(4'-cyano-phenyl)methyl)benzene using both ionothermal reaction conditions with ZnCl at 400 °C and the milder reaction conditions with the strong Brønsted acid trifluoromethanesulfonic acid (TFMS) at room temperature. Additionally, the hexanitrile was combined with different di-, tri-, and tetranitriles as a second linker based on recent work of mixed-linker CTFs, which showed enhanced carbon dioxide captures. The obtained framework structures were characterized via infrared (IR) spectroscopy, elemental analysis, scanning electron microscopy (SEM), and gas sorption measurements. Nitrogen adsorption measurements were performed at 77 K to determine the Brunauer-Emmett-Teller (BET) surface areas range from 493 m/g to 1728 m/g (/ = 0.01-0.05). As expected, the framework synthesized from with ZnCl possesses the highest surface area for nitrogen adsorption. On the other hand, the mixed framework structure formed from the hexanitrile and 1,3,5 tricyanobenzene () shows the highest uptake of carbon dioxide and methane of 76.4 cm/g and 26.6 cm/g, respectively, at 273 K.