Chemisorption of CO2 by diamine-tetraamido macrocyclic motifs: a theoretical study.

Although alkanolamines have been systematically utilized for CO2 capture, intensive research efforts are still required to ultimately design more efficient CO2 sorbents with appropriate sorption characteristics. In this article, we have explored a series of diamine-tetraamido macrocyclic molecules with different organic linkers, namely, pyridine, phenylene, pyrrole, furan, and thiophene, for the titled purpose using quantum chemical calculations. The optimized structures of the sequestration reaction revealed the formation of a carbamate anion within the macrocyclic cavity that was stabilized through several intramolecular interactions compared to parent amines. The reaction thermodynamics indicated that the macrocyclic compounds with pyridine, pyrrole and furan can effectively capture CO2. The results highlight the potential application of macrocyclic structures as efficient CO2 capturing agents.