Triptycene-based porous photoluminescent polymers with dual role: efficient capture of carbon dioxide and sensitive detection of picric acid

Design and synthesis of unique photoluminescent triptycene-based porous polymers (TBP-OH and TBP-NH2) bearing active functional groups is described herein. Pd catalyzed Sonogashira cross-coupling reaction was utilized to obtain these polymeric networks that are nanoporous and strongly fluorescent in THF. In solid state, these polymers demonstrated CO2 uptake up to 92 mg g−1 at 273 K/1bar and H2 up to 16 mg g−1 at 77 K/1bar which may be attributed to the presence of 3D robust triptycene and CO2-philic groups –OH and –NH2 in their polymeric framework. TBP-OH and TBP-NH2 also selectively capture CO2 over nitrogen and methane. CO2 capture by TBP-OH and TBP-NH2 is a physisorption process and hence reversible in nature. Suspensions of TBP-OH and TBP-NH2 in THF are strongly fluorescent and are also capable of detecting picric acid (an environmental pollutant and explosive) in trace amounts. The Stern–Volmer quenching constants (Ksv) for detection of picric acid (PA) are in the order of 105 M−1.