A nitrogen-rich, azaindole-based microporous organic network: synergistic effect of local dipole–π and dipole–quadrupole interactions on carbon dioxide uptake

Abstract

A new type of microporous organic polymer with azaindole units (N-PEINK) has been designed. The resulting N-PEINK exhibits good chemical and thermal stability with a decomposition temperature of 550 °C. Taking advantage of the synergistic effect of local dipole–π and dipole–quadrupole interactions between azaindole and carbon dioxide (CO₂), the CO₂ uptake capacity of the polymer reaches 20.8 wt% (1.0 bar, 273 K) with high selectivities (CO₂/N₂ = 97, CO₂/CH₄ = 18), making the polymer a promising microporous material for application in CO₂ separation and capture. Furthermore, the azaindole-based microporous organic polymer also exhibits a high hydrogen storage (2.67 wt%) at 1.0 bar and 77 K. For comparison, the microporous organic polymer with indole units (PEINK) was also prepared.