Hierarchical porous organic hyper-cross-linked polymers containing phthalazinone and carbazole moieties for gas uptake and fluorescence properties

Based on rigid and twisted heterocyclic phthalazinone unit as the core skeleton, novel hierarchical porous carbazole-containing porous organic polymers (PCMOPs) were successfully constructed through Friedel-Crafts reaction (PCMOP-Hs) and oxidation coupling reaction (PCMOP-Os), respectively, with anhydrous FeCl 3 as catalyst. The structures of resultant PCMOPs were characterized by FT-IR, 13 C CP-MAS NMR and WXRD. PCMOP-Hs displayed higher BET surface area (660–675 m 2 g −1 ), CO 2 uptake capacity (11.8–12.1 wt%, 273 K, 1 bar) and CO 2 /N 2 selectivity (up to 78.46, IAST) than those of PCMOP-Os, respectively. Even though, PCMOP-Os both displayed high sensitivity and selectivity with the fluorescent quenching rate value up to 83% for 2,4-dinitrotoluene (DNT) and 70% for nitrobenzene (NB) in low concentration (10 −2 mol/L). The properties along with large-scale and low-cost preparation make these hierarchical POPs potential candidates for gas storage and separation as well as fluorescence detection of explosives application.