Conjugated microporous polymers using a copper-catalyzed [4 + 2] cyclobenzannulation reaction: promising materials for iodine and dye adsorption

Abstract

A design strategy is disclosed to synthesize conjugated microporous polymers (CMPs) using a versatile copper-catalyzed [4 + 2] cyclobenzannulation reaction, which employs a diphenylethynyl terephthalaldehyde derivative 3 with a series of triptycene-based diethynyl aryl building blocks 2a–e. Investigation of the intrinsic microporosity properties of CBP1–5 using nitrogen adsorption measurements reveals Brunauer–Emmett–Teller (BET) surface areas up to 794 m² g⁻¹ and average pore volumes reaching 0.63 cm³ g⁻¹. Inspection of the adsorption properties of the graphitic-like polymers CBP1–5 divulges their high iodine uptake with a maximum of 166 wt%. Moreover, the target polymers CBP1–5 prove their efficiency as selective dye adsorbents by removing up to 100% methylene blue over methyl orange from aqueous solution.