title: Macrocyclic influences in CO₂ uptake and stabilization.
abstract: Two 24-member diamine-tetraamido macrocycles (R = H and CH3), readily synthesized in one or two steps, were found to react with CO2 rapidly and efficiently (100% conversion within 1 min at rt). The resulting carbamate formation was demonstrated by (1)H, (13)C NMR, ESI-MS, and X-ray crystallography. The crystal structure clearly showed the carbamate group (N-CO2(-)) formed was tightly bound within the macrocyclic cavity, held by five internal hydrogen bonds, and stabilized by intramolecular carbamate-ammonium salt-bridge formation.
authors.affiliation: Department of Chemistry, University of Kansas , 1251 Wescoe Hall Drive, Lawrence, Kansas 66045, United States.
authors.forename: Qi-Qiang
authors.initials: QQ
authors.lastname: Wang
authors.forename: Victor W
authors.initials: VW
authors.lastname: Day
authors.forename: Kristin
authors.initials: K
authors.lastname: Bowman-James