Tröger's Base-Enriched Conjugated Cyclopentannulated Copolymers: Prominent Adsorbents of CO₂, H₂, and Iodine

Three copolymers with conjugated structures, PTB1-PTB3, were produced utilizing a palladium-catalyzed cyclopentannulation polymerization by reacting a specially designed diethynyl Tröger's base surrogate with different dihalogenated polycondensed aromatic hydrocarbons. Brunauer, Emmet, and Teller nitrogen gas adsorption investigation revealed the surface areas of the copolymers, attaining ∼365 m² g^-1. Gas uptake studies demonstrated a considerable carbon dioxide uptake for PTB2 of 44.41 mg g^-1 at 273 K and a promising H₂ gas uptake of 3.18 mg g^-1 at 77 K. PTB1-PTB3 displayed a sizable iodine adsorption capacity, achieving 4000 mg g^-1, and mechanistic investigations demonstrated the prevalence of a pseudo-second-order kinetic model. Recyclability experiments proved the effective regeneration of the copolymers, even after performing several adsorption and desorption tests.