Controlled synthesis of conjugated polycarbazole polymers via structure tuning for gas storage and separation...

A series of conjugated microporous polymers (CMPs) based on 1,3,6,8-tetrabromocarbazole (N₄CMP-1-5) is synthesized via Suzuki cross-coupling or Sonogashira polycondensation. The porosity properties and surface area of these polymer networks can be finely tuned by using a linker with different geometries or strut length. These polymers show the Brunauer-Emmett-Tellerthe (BET) surface areas ranging from 592 to 1426 m² g^-1. The dominant pore sizes of the polymers on the basis of the different linker are located between 0.36 and 0.61 nm. Gas uptake increases with BET surface area and micropore volume, N₄CMP-3 polymer can capture CO₂ with a capacity of 3.62 mmol g^-1 (1.05 bar and 273 K) among the obtained polymers. All of the polymers show high isosteric heats of CO₂ adsorption (25.5-35.1 kJ mol^-1), and from single component adsorption isotherms, IAST-derived ideal CO₂/N₂ (28.7-53.8), CO₂/CH₄ (4.6-5.2) and CH₄/N₂ (5.7-10.5) selectivity. Furthermore, N₄CMPs exhibit the high CO₂ adsorption capacity of 542-800 mg g^-1 at 318 K and 50 bar pressure. These data indicate that these materials are a promising potential for clean energy application and environmental field.