Polyphenylene networks containing triptycene units: Promising porous materials for CO2, CH4, and H2 adsorption

Abstract

The synthesis of triptycene-based three-dimensional networks and their uptake towards various gases are described. The target polymers TPP1-3 were synthesized by employing a convenient palladium-catalyzed Suzuki-Miyaura cross-coupling reaction between a triptycene synthon bearing two peripheral dibromotetraphenyl benzene ( TBT ) units and various arylboronic acid/ester moieties. Polymers TPP1-3 were characterized by several instrumental analysis techniques, namely, solid-state 13 C nuclear magnetic resonance (SSNMR), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR), and emission spectrophotometry. Brunauer-Emmett-Teller (BET) nitrogen adsorption investigation of TPP1-3 revealed surface areas up to 468 m 2 g −1 and an average pore volume of ~0.25 cm 3 g −1 . Interestingly, low-pressure gas adsorption studies of TPP1-3 disclosed a CO 2 uptake for TPP1 of 78.4 mg g −1 (273 K) and a gas adsorption capacity for TPP2 towards H 2 and CH 4 of 10 mg g −1 (77 K) and 7.9 mg g −1 (273 K), respectively. • Synthesis of new polyhenylene networks TPP1-3 bearing triptycene units is reported. • Gas sorption study show BET surface area up to 468 m 2 /g and pore volume of 0.25 cm 3 /g. • CO 2 adsorption capacity discloses a promising uptake of 78.4 mg g −1 at 273 K for TPP1 . • TPP2 uptakes 10 mg g −1 of H 2 at 77 K and 7.9 mg g −1 of CH 4 at 273 K.