Enhanced CO₂ uptake by intramolecular proton transfer reactions in amino-functionalized pyridine-based ILs

Abstract

This work presents a new strategy for the promotion of CO uptake by an intramolecular proton transfer reaction in amino functionalized hydroxypyridine based anions.

High Performing CO2 Capture by Smart Strategies in Functionalized Ionic Liquids

“…[11] As shown in Figure 1a (Figure 1b). The multi-site interactions between [IDA] and CO2 were further verified by FT-IR and 13 C NMR spectra (Figures 1c and 1d). In the IR spectra, the peak attributable to N-H stretch disappeared and simultaneously, two new characteristic peaks were observed at 1630 and 1423 cm -1 attributable to NH-CO2 and O-CO2 interactions, respectively.…”

“…Proposed reaction between the first TSIL [apbim][BF4] and CO2. [6] Smart strategies including basicity tuning/dual tuning methods, [8,9] multi-site cooperative interactions, [10][11][12] and intramolecular hydrogen bonding/intra-molecular proton transfer [13,14] has been employed into ILs for CO2 capture. For examples, Dai et al [8] investigated the relationship between the enthalpy of CO2 absorption and the pKa value in a series of non-amino functionalized ILs and concluded that it is possible to achieve both efficient CO2 uptake and energy-saving release by simply tuning the basicity of the anion of IL.…”

“…Cui and co-workers [12] demonstrated a novel strategy based on cooperative interactions between CO2 and multiple active sites in the pre-organized anion for highly efficient and reversible capture of low-concentration CO2. Recently, Pan et al [13,14] established a series of amino-functionalized ILs for efficient CO2 absorption as well as controllable viscosity change during the uptake process by creating intra-molecular hydrogen bonding or intra-molecular proton transfer. Therefore, the aim of this mini-review is to outline some typical advances in functionalized ILs for highly efficient, fast, and reversible capture of CO2 in recent years.…”

“…Secondly, non-amino functionalized ILs such as azolide or phenolate ILs were designed in consideration of the lack of proton donor and acceptor in such systems. [8,13] Recently, Pan and co-workers [13] designed a series of amino-functionalizd ILs that possess equimolar and fast absorption of CO2 by setting an amino group in the vicinity of negative oxygen atom in the pyridine anion (Scheme 4). Once CO2 reacts with the amino group to form the carbamic acid, and subsequently the proton on carbamic acid can transfer to the negative oxygen group in the anion, resulting in enhanced CO2 absorption capacity and improved uptake kinetics.…”

Absorption and thermodynamic properties of CO2 by amido-containing anion-functionalized ionic liquids

“…[5][6][7][8][9] In light of the reaction mechanism of CO 2 in alkanolamine solutions and the outstanding properties of ILs, Davis et al 10 rst reported imidazolium ILs with amino-graed cation for the chemical absorption of CO 2 . Since the anion plays a key role in carbon capture, worldwide researchers have developed many kinds of task-specied ILs with the functionalized anions such as amino acids, [11][12][13][14] azolates, [15][16][17][18][19][20] phenolates, 7,[21][22][23] and acetate. 24 Compared with conventional ILs, these anion-functionalized ILs typically have high CO 2 absorption capacity and selectivity.…”