A porphyrin-linked conjugated microporous polymer with selective carbon dioxide adsorption and heterogeneous organocatalytic performances

Abstract

A new porphyrin-based conjugated microporous polymer with rich nitrogen sites in the skeleton has been synthesized by alkyne–alkyne homocoupling reaction. The Brunauer–Emmett–Teller specific surface area up to 662 m² g⁻¹ was obtained for the new polymer framework with a pore volume of 0.55 cm³ g⁻¹. The polymer network displays high carbon dioxide uptake capacity (up to 3.58 mmol g⁻¹) at 273 K and 1 bar, with good selectivity towards CO₂ over N₂ and CH₄. Furthermore, this framework also acts as a solid organocatalyst towards Knoevenagel reaction of malononitrile with aromatic, heterocyclic aldehydes, and cyclic ketones. The reaction afforded the corresponding products in excellent yields (up to 99%) with short times. Moreover, the heterogeneous catalyst was also found to exhibit an excellent recyclability (up to 10 times) without loss of efficiency.