1-ethyl-3-methylimidazolium-2-carboxylate

• CAS: 1017847-51-6
• Catalog Number: ACM1017847516
• Category: Main Products
• Molecular Weight: 154.17
• Molecular Formula: C7H10N2O2

Case Study

1-Ethyl-3-Methylimidazolium-2-Carboxylate as A Product of The CO2 Capture

Samuel Seo, et al. J. Phys. Chem. B 2014, 118, 51, 14870-14879.

Ionic liquids (ILs) with aprotic heterocyclic anions (AHA) with 1-ethyl-3-methylimidazolium ([emim]+) cations are attractive candidates for CO2 capture. AHA is a basic anion capable of reacting stoichiometrically with CO2 to form carbamate species. The formation of 1-ethyl-3-methylimidazolium-2-carboxylate upon exposure to CO2 under mild conditions (22 °C, 1 bar) has been confirmed in the liquid phase using 1H and 13C NMR spectroscopy.
· The size of the resonance peaks in the highlighted region (associated with protons on 1-ethyl-3-methylimidazolium-2-carboxylate) gradually diminishes upon the start of the desorption step.After 5 h, the duplicate peaks have completely disappeared, and the 1H NMR spectrum is identical to that of the pure [emim][2-CNPyr].
· The fully desorbed sample was recovered and used for the second CO2 absorption cycle. The isotherm obtained using the desorbed sample was identical to that of the initial sample.
· The reaction of 1,3-diethylimidazolium acetate ([eeim][OAc]) or 1- butyl-3-methylimidazolium acetate ([bmim][OAc]) with CO2 was reversible at reduced pressure with mild heating.

CO2 Absorption of 1-Ethyl-3-Methylimidazolium Ionic Liquid

Umecky, Tatsuya, et al. Journal of CO2 Utilization, 2019, 31, 75-84.

The CO2 absorption characteristics and reaction mechanism of three 1-ethyl-3-methylimidazolium ionic liquids ([C2mim]+) were studied, namely [C2mim][acac], [C2mim][tfacac], and [ C2mim][hfacac]. The CO2 chemisorption product proves 1-ethyl-3-methylimidazolium-2-carboxylate, supporting the elimination of the H2c hydrogen atom from [C2mim]+ cation.
Mechanism of CO2 chemisorption
· 1-Ethyl-3-methylimidazolium-2-carboxylate is formed by simultaneous occurrence of the making of the carbon-carbon bond between CO2 molecule and the carbon atom at the 2-position of 1,3- dialkylimidazolium cation and the breaking of the carbon-hydrogen covalent bond at the 2-position of the cation.
· As the strength of the interaction between the anion and the imidazolium cation becomes larger beyond the threshold, the elimination of the hydrogen atom of the 1,3-dialkylimidazolium cation may be progressed.
· An anion in 1,3- dialkylimidazolium IL probably plays the role of the covalent bond breaker in the formation of 1-ethyl-3-methylimidazolium-2-carboxylate.
The chemisorption of CO2 in the ILs increased in the order of [C2mim][Tf2N] ≈ [C2mim][TFA] ≈ [C2mim][tfacac] ≈ [C2mim] [hfacac] < [C2mim][acac] < [C2mim][AcO].

Study on CO2 absorption of 1-ethyl-3-methylimidazolium-2-carboxylate

Makino, Takashi, Tatsuya Umecky, and Mitsuhiro Kanakubo.Industrial & Engineering Chemistry Research 55.50 (2016): 12949-12961.

The physical properties of [emim][AcO], [emim][C1OC2OC1CO2] and [emim][C1(OC2)2CO2] at atmospheric pressure and CO2 solubility over a wide pressure range were measured. 2-methoxyethoxy and 2-methoxyethoxymethyl functionalization of acetate increased density and viscosity and decreased conductivity compared to [emim][AcO]. 2-Methoxyethoxy has a greater impact on physical properties than 2-methoxyethoxymethyl. Each carboxylate ionic liquid chemically absorbs CO2 and desorbs the CO2 through heating. In the present system, the [emim]+ cation and CO2 form the complex 1-ethyl-3-methylimidazole-2-carboxylate and generate the corresponding carboxylic acid as a by-product. Both ether modifications weaken the basicity of the carboxylate, resulting in a decrease in CO2 solubility in the functionalized ionic liquid. The effect of 2-methoxyethoxy on CO2 chemisorption under normal pressure is more significant than that of 2-methoxyethoxymethyl. Furthermore, the solubility of high-pressure CO2 in existing ionic liquids was successfully decomposed into contributions from chemical and physical absorption. Numerical analysis was performed based on two equilibria, (1) physical dissolution of CO2 in gas-liquid equilibrium and (2) 1-ethyl-3-methylimidazole-2-carboxylate and the reaction between carboxylic acid and carboxylate The formation of dimer anions. Experimental validation of the [emim][AcO] + CO2 system using quantitative 13C NMR at high pressure validates the validity of the analysis. Solubility after decomposition showed that 2-methoxyethoxy modification increased physical adsorption and decreased chemisorption, whereas 2-methoxyethoxymethyl modification had a negative impact on both chemical and physical adsorption. The enhancement of physical absorption in [emim][C1OC2OC1CO2] results from positive entropic effects, whereas negative entropic effects are observed in [emim][C1(OC2)2CO2]. Ether modification on the carboxylate anion can improve CO2 physisorption.
Methods for measuring CO2 solubility at atmospheric pressure are described in detail elsewhere. Use an electronic balance glove box. A glass cell containing IL was immersed in a thermostatic bath using a circulator. Preheated gas was supplied to the IL very slowly through the inlet needle and stirred with a magnetic rod. The weight of the carboxylate IL and N2, wN2, and CO2, cells after saturation with wCO2 was measured using another balance. current situation. CO solubility is expressed as the molar ratio of CO to IL, α1= (w1/M1)/(w2/M2), and the mole fraction of CO x1 = (w1/M1)/(w1/M1+ w2/M2). Co-solubility was measured using the following temperature sequence: from 313, 333, 283, 298, 353 and 373, to 313 K. The CO pressure p is atmospheric pressure (0.101±0.001 MPa), i.e. checked using a barometer, and the temperature T is kept constant using a platinum resistance thermometer. After measurement, each IL was saturated with CO at 313.2 K and transferred to NMR tubes, which were then quickly sealed in a dry glove box for NMR measurements.

1-ethyl-3-methylimidazolium-2-carboxylate participates in the study of the properties of ionic liquids

Watanabe, Masayoshi, and Hiroyuki Tokuda. Ionic Liquids Further UnCOILed: Critical Expert Overviews (2014): 217-234.

Ionic liquids with the conjugate base of the protic acid as the counter anion can be easily prepared by the CO-releasing reaction by neutralizing 1-ethyl-3-methylimidazolium-2-carboxylate with a protic acid that is more acidic than carbonic acid. The obtained ionic liquids do not require special purification procedures. The method was successfully applied to the preparation of [Cmim][CFCO], [Cmim][CHSO], and [Cmim][CHCO]. The physicochemical properties, especially the transport properties, of 1-ethyl-3-methylimidazolium ionic liquids with [CFCO], [CHSO], [CHCO], [CFSO], [BF], and [N(CFSO)] anions were precisely measured. The data for the first four ionic liquids are provided in this study for the first time. The ionicity of ionic liquids is controlled by the magnitude and balance of Coulomb forces, which in this study are mainly modified by the anion Lewis basicity and van der Waals forces. The ionicity Λ/Λ of ionic liquids is 0.5~0.8, and the order of anion dependence is [BF]>[N(CFSO)]>[CFSO]>[CFC O]>[CHSO]>[CHCO], which is the reciprocal order of anion donor ability or the acidity order of conjugate acid. The viscosity of various 1-ethyl-3-methylimidazolium and 1-butyl-3-methylimidazolium ionic liquids is related to the effective ion concentration C, which is estimated based on the ionicity and molar concentration of these ionic liquids. The viscosity tends to increase with increasing C, although at the same C value, 1-butyl-3-methylimidazolium ionic liquids show higher viscosity than 1-ethyl-3-methylimidazolium ionic liquids due to the enhanced van der Waals effect.
The ionic liquids [Cmim][CFCO], [Cmim][CHSO] and [Cmim][CHCO] were synthesized by the CO release reaction of 1-ethyl-3-methylimidazolium 2-carboxylate with CFCOH, CHSOH and CHCl3. 1-Ethylimidazole, dimethyl carbonate and anhydrous methanol were placed in a pressure vessel and mixed at 120°C for 36 hours. Methanol was removed from the reaction mixture under reduced pressure to obtain a white solid, which was purified by recrystallization from an acetonitrile-tetrahydrofuran mixture. A methanol solution of 1-ethyl-3-methylimidazolium-2-carboxylic acid was added dropwise to a methanol solution of CFCOH, CHSOH and CHCl3, stirred for several hours and dried under reduced pressure at 60°C to remove methanol, yielding [Cmim][CFCO], [Cmim][CHSO] and [Cmim][CHCO], respectively. [Cmim][CFSO] was prepared by the double decomposition reaction of [Cmim]Cl and Na[CFSO]. [Cmim][CFSO] was finally dehydrated by heating under high vacuum for 48 hours. The obtained [Cmim] ionic liquids were stored in an argon atmosphere glove box ([O] < 1 ppm; [H2O] < 1 ppm). The structures of the ionic liquids were identified by 1H and 13C NMR spectroscopy and fast atom bombardment mass spectrometry (FAB-MS). The chlorine content in [Cmim][CFSO] remained at least below the solubility limit of AgCl in water (1.4 mg/l), which was checked by adding AgNO solution. The water content of all ionic liquids was less than 40 ppm as determined by Karl Fischer titration.

Custom Q&A

What is the molecular formula of 1-ethyl-3-methylimidazolium-2-carboxylate?

The molecular formula is C7H10N2O2.

What is the molecular weight of 1-ethyl-3-methylimidazolium-2-carboxylate?

The molecular weight is 154.17 g/mol.

What is the IUPAC name of 1-ethyl-3-methylimidazolium-2-carboxylate?

The IUPAC name is 1-ethyl-3-methylimidazol-3-ium-2-carboxylate.

What is the InChI of 1-ethyl-3-methylimidazolium-2-carboxylate?

The InChI is InChI=1S/C7H10N2O2/c1-3-9-5-4-8(2)6(9)7(10)11/h4-5H,3H2,1-2H3.

What is the InChIKey of 1-ethyl-3-methylimidazolium-2-carboxylate?

The InChIKey is AACQANZPAVCEIV-UHFFFAOYSA-N.

What is the canonical SMILES of 1-ethyl-3-methylimidazolium-2-carboxylate?

The canonical SMILES is CCN1C=C[N+](=C1C(=O)[O-])C.

What is the XLogP3-AA value of 1-ethyl-3-methylimidazolium-2-carboxylate?

The XLogP3-AA value is 1.

How many hydrogen bond donor count does 1-ethyl-3-methylimidazolium-2-carboxylate have?

It has 0 hydrogen bond donor count.

How many hydrogen bond acceptor count does 1-ethyl-3-methylimidazolium-2-carboxylate have?

It has 2 hydrogen bond acceptor count.

What is the topological polar surface area of 1-ethyl-3-methylimidazolium-2-carboxylate?

The topological polar surface area is 48.9Ų.