Triptycene based 1,2,3-triazole linked network polymers (TNPs): small gas storage and selective CO2 capture

Abstract

Herein, facile synthesis and characterization of four triazole linked network polymers (TNPs) in high yields is described. These nitrogen rich polymers are derived using a “click” reaction between 2,6,14-triazido triptycene and various di- or triethynyl comonomers. The TNPs are microporous and exhibit high surface area (SA_BET up to 1348 m² g⁻¹). Due to the incorporation of the 1,2,3-triazole motif (a CO₂-philic moiety), the TNPs record moderate to high CO₂ uptake (up to 4.45 mmol g⁻¹ at 273 K and 1 bar). The TNPs also show very good CO₂/N₂ (up to 48) and CO₂/CH₄ (8–9) selectivity. While the highest storage capacity has been registered by TNP4 (CO₂ 4.45 mmol g⁻¹ at 273 K and 1 bar, CH₄ 23.8 mg g⁻¹, H₂ 1.8 wt%), the highest CO₂/N₂ and CO₂/CH₄ selectivity is shown by TNP3 which contains additional nitrogen rich building blocks in the form of heteroaromatic pyrazine rings. These results suggest that TNPs are porous materials with potential practical application in gas storage and separation.