Synthesis of π‐conjugated network polymers based on fluoroarene and fluorescent units via direct arylation polycondensation and their porosity and fluorescent properties

Abstract

ABSTRACTIn this study, we report the synthesis of π‐conjugated network polymers including unique fluorescent units via palladium‐catalyzed direct (CH) arylation polycondensation of 1,2,4,5‐tetrafluorobenzene with tetrabromoarenes. The obtained polymers, including tetraphenylethene (TPE) or pyrene (PYR) units, had microporous structures with the specific Brunauer–Emmett–Teller (BET) surface areas at 508 and 824 m2 g−1, respectively. These polymers possessed narrow pore distributions (<15 nm). These analyses supported that π‐conjugated microporous polymers (CMPs) were synthesized by the direct arylation. Similar to the result of BET surface areas, carbon capture capacity of CMP based on PYR unit was higher than that of CMP based on TPE unit. Because the nitrogen capture capacity of these CMPs was low (≈ 0), selectivity of carbon dioxide adsorption was very high. TPE is a typical aggregation‐induced emission unit but PYR is an aggregation‐caused quenching (ACQ) molecule. The incorporation of TPE unit into the microporous polymer gave green‐colored fluorescence (Φ = 0.12). The polymer including PYR units also showed the green‐colored fluorescence (Φ = 0.05) even though the ACQ property. These synthesized CMPs exhibited characteristic solvatofluorochromism. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3862–3867