Thienyltriazine-based porous organic polymers with nitrogen rich moieties: synthesis and gas selectivity study

Here, we present the synthesis of a series of thienyltriazine-containing nitrogen-rich porous organic polymers by making use of Sonogashira coupling reaction (for TT-CBz, TT-BCBz and TT-TPA) and FeCl3-mediated polymerization (for TT-TCBz-(a-g)). The FeCl3-mediated polymerization was performed under different reaction conditions, such as oxidative polymerization, Friedel-Crafts polymerization, and competitive oxidative/Friedel-Crafts polymerizations. Polymer TT-TCBz-b, synthesized at room temperature in the presence of FeCl3 and MeNO2, displayed the highest BET surface area of approximately 1059 m2 g-1. However, the percentage of micropore volume was largest for TT-TCBz-f and TT-TCBz-g, which can be attributed to their highly cross-linked structure. All of the polymers exhibited notable thermal stability, with the TT-TCBz series polymers reaching stability as high as 580 degrees C. The polymers of the TT-TCBz series were also used for CO2 adsorption studies. The rich heteroatom content, presence of an electron-rich carbazole unit and high micropore volume make these polymers attractive candidates for sequestration of Lewis acidic CO2 gas. A maximum CO2 uptake of 16.5 wt% at 263 K and 100 kPa has been observed for TT-TCBz-g attributed to its high surface area and high percentage of micropore volume. IAST results further revealed that in TT-TCBz-g the selectivity for the CO2 : N2 mixture (15 : 85) is around 65. A series of thienyltriazine-based porous polymers have been synthesized and explored for CO2 adsorption with the uptake reaching as high as 16.5 wt% at 263 K and 100 kPa and a selectivity of around 65 for the CO2 : N2 mixture (15 : 85).