Facile synthesis of porous organic polymers bifunctionalized with azo and porphyrin groups

Azo and porphyrin bifunctionalized porous polymers networks (azo-PPors) were synthesized via a catalyst-free direct coupling of tetra(4-nitrophenyl)porphyrin and several readily available aryl amine monomers. The resulting porous solids exhibited surface areas up to 750 m² g^-1, with high thermal and chemical stability. Owing to the high concentration of Lewis basic N-sites at their surfaces (derived from porphyrin rings and azo units), these azo-PPors have high CO₂ capture (up to 2.45 mmol g^-1) and good selectivity for CO₂/CH₄ adsorption (5) at 273 K/1.0 bar, thus showing good potential for CO₂ capture.