title: Cation-assisted interactions between N-heterocycles and CO2.
abstract: Cation-assisted interactions between N-containing heterocycles (NHCs) and CO2 have been systematically studied by using density functional theory (DFT). For neutral and anionic (non-carbenoid) NHCs, the effects of monovalent cations (i.e., alkali metal ions) are moderate to small (the NHC-CO2 binding energy change, ΔBE usually < 25 kJ mol(-1)). However, for NHC carbenes, due to their strong basicity, the effects are strong (ΔBE > 60 kJ mol(-1)) and the monovalent cations play a critical role in the single carboxylation of dicarbenes with CO2. In comparison, divalent alkali earth metal cations, due to both their smaller sizes and higher formal charges, exhibit a much stronger influence (ΔBE > 100 kJ mol(-1)). Divalent cations should be incorporated into next generation CO2 capture reagents. Other aspects including the reaction potential energy surface (PES), orbital-based analyses of interactions, substitution effects, and the reactivity descriptors (cation size, reacting N lone pair orbital energy, etc.) have been discussed in detail as well.
authors.affiliation: School of Materials Science and Engineering & Center for Advancing Materials Performance from the Nanoscale (CAMP-Nano) & State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China.
authors.forename: Huarong
authors.initials: H
authors.lastname: Tang
authors.forename: Dongmei
authors.initials: D
authors.lastname: Lu
authors.forename: Chao
authors.initials: C
authors.lastname: Wu