title: Nucleophilicity and accessibility calculations of alkanolamines: applications to carbon dioxide absorption reactions.
abstract: Both nucleophilicities and accessibilities of three alkanolamines [monoethanolamine (MEA), (2-(methylamino)ethanol (MAE), and 2-amino-2-methyl-1-propanol (AMP)] were calculated to predict their reactivities with CO(2). After DFT geometry-optimization calculations, the global, group, and atomic nucleophilicities of each amine were obtained using MP2 quantum mechanical calculations. Only global nucleophilicity matched an experimental pK(a) order (MAE > AMP > MEA). However, it failed to predict the slow rate of the sterically hindered AMP and the order of rate constants, MAE > MEA > AMP. The accessibilities of amines to CO(2) have been calculated by MD simulations by monitoring collisions at the reaction centers: N atoms in amines and C in CO(2). The accessibility results indicate that global nucleophilicity needs quantitative correction for steric effects to predict better reactivities of amines with CO(2).
authors.affiliation: Department of Chemistry, Soongsil University, 511 Sangdo-Dong, Dongjak-Gu, Seoul 156-743, Korea.
authors.forename: Young H
authors.initials: YH
authors.lastname: Jhon
authors.forename: Jae-Goo
authors.initials: JG
authors.lastname: Shim
authors.forename: Jun-Han
authors.initials: JH
authors.lastname: Kim
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Lee
authors.forename: Kyung-Ryong
authors.initials: KR
authors.lastname: Jang
authors.forename: Jaheon
authors.initials: J
authors.lastname: Kim
mesh_terms: D000042:Absorption; D000438:Alcohols / Q000737:chemistry*; D000588:Amines / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D015394:Molecular Structure; D011789:Quantum Theory; D013499:Surface Properties
chemical_list: D000438:Alcohols; D000588:Amines; D002245:Carbon Dioxide