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 (K_sv) for detection of picric acid (PA) are in the order of 10⁵ M⁻¹.