Preparation of a series of aCTV-based covalent organic frameworks and substituent effects on their properties

Abstract

A series of amino substituted cyclotrianisylene (aCTV)-based covalent organic frameworks (COFs), aCTV-COF1 to aCTV-COF4, have been synthesized. These crystalline analogues showed permanent porosity with BET surface areas from 656 m² g⁻¹ to 1428 m² g⁻¹. With the introduction of methoxy groups and hydroxyl groups at the phenyl linker moieties in aCTV-COF3 and aCTV-COF4, their properties (such as color, gas adsorption, hydrolytic stability and so on) have been influenced to a great extent. The CO₂ sorption of aCTV-COF4 has increased significantly, and the H₂ uptake of aCTV-COF3 is obviously higher than those of aCTV-COF1 and aCTV-COF2. Moreover, the introduction of the methoxy and hydroxyl groups has made aCTV-COF3 and aCTV-COF4 have better hydrolytic stability.