Revisiting Nitrogen Species in Covalent Triazine Frameworks

Abstract

Covalent\ntriazine frameworks (CTFs) are porous organic materials\npromising for applications in catalysis and separation due to their\nhigh stability, adjustable porosity, and intrinsic nitrogen functionalities.\nCTFs are prepared by ionothermal trimerization of aromatic nitriles;\nhowever, multiple side reactions also occur under synthesis conditions,\nand their influence on the material properties is still poorly described.\nHere we report the systematic characterization of nitrogen in CTFs\nusing X-ray photoelectron spectroscopy. With the use of model compounds,\nwe could distinguish several types of nitrogen species. By combining\nthese data with textural properties, we unravel the influence that\nthe reaction temperature, the catalyst, and the monomer structure\nand composition have on the properties of the resulting CTF materials.