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Katsyuba SA, Grimme S. Structure and intermolecular interactions in ionic liquid 1-ethyl-3-methylimidazolium bromide and its aqueous solutions investigated by vibrational spectroscopy and quantum chemical computations. J Comput Chem 2024. [PMID: 39139057 DOI: 10.1002/jcc.27472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 06/10/2024] [Accepted: 07/13/2024] [Indexed: 08/15/2024]
Abstract
The recently developed efficient protocol to explicit quantum mechanical modeling of structure and IR spectra of liquids and solutions (S. A. Katsyuba, S. Spicher, T. P. Gerasimova, S. Grimme, J. Phys. Chem. B 2020, 124, 6664) is applied to ionic liquid (IL) 1-ethyl-3-methylimidazolium bromide (EmimBr), its C2-deuterated analog [Emim-d]Br and its aqueous solutions. It is shown that the solvation strongly modifies frequencies and IR intensities of the CH/CD stretching vibrations (νCH/νCD) of the imidazolium ring. The main vibrational spectroscopic features of the neat IL are reproduced by the simulations for a cluster (EmimBr)9, in which all three imidazolium CH moieties of the solvated cation form short contacts with three Br- anions, and another two Br- anions are located on top and bottom of imidazolium ring. Cluster models of aqueous solutions reproduce the experimental vibrational frequencies of actual solutions, provided that the Br- anion of solvated contact ion pair (CIP) is situated on top of imidazolium ring, and CH/CD moieties of the latter participate in short contacts with surrounding water molecules. Both structural and spectroscopic analysis allow to interpret the short contacts CH/CD⋯Br- and CH/CD⋯OH2 as hydrogen bonds of approximately equal strength. Enthalpies of bonding of these liquid-state H-bonds, estimated with the use of empirical correlations, amount to ca. 1.4 kcal⋅mol-1, while the analogous estimates obtained for the gas-phase charged species [Emim]2Br+ increase to 5.6 kcal⋅mol-1. It is shown that formation of solvent-shared ion pair (SIP) in aqueous solution, where the counterions of IL are separated by two water molecules H-bonded to a Br- anion, produces frequency shifts ΔνCH/CD, strongly different from the case of CIP formation. This difference can be used for IR/Raman spectroscopic differentiation of the type of solvated ion pairs of EmimBr or other related ILs.
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Affiliation(s)
- Sergey A Katsyuba
- Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Centre of RAS, Kazan, Russia
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry, Clausius Institut für Physikalische und Theoretische Chemie der Universität Bonn, Bonn, Germany
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Katsyuba SA, Zvereva EE. What quantum chemical simulations tell us about the infrared spectra, structure and interionic interactions of a bulk ionic liquid. Phys Chem Chem Phys 2022; 24:7349-7355. [PMID: 35266472 DOI: 10.1039/d1cp05745f] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The recently developed efficient protocol to explicit quantum mechanical modeling of the structure and IR spectra of liquids and solutions [Katsyuba et al., J. Phys. Chem. B, 2020, 124, 6664-6670] is applied to ionic liquid 1-ethyl-3-methyl-imidazolium tetrafluoroborate [Emim][BF4], and its C2-deuterated analog [Emim-d][BF4]. It is shown that the solvation strongly modifies the frequencies and IR intensities of both cationic and anionic components of the ionic liquids. The main features of the bulk spectra are reproduced by the simulations for cluster ([Emim][BF4])8, representing an ion pair solvated by the first solvation shell. The geometry of the cluster closely resembles the solid-state structure of the actual ionic liquid and is characterized by short contacts of all CH moieties of the imidazolium ring with [BF4]- anions. Both structural and spectroscopic analyses allow the contacts to be interpreted as hydrogen bonds of approximately equal strength. The enthalpies of these liquid-state H-bonds, estimated with the use of empirical correlations, amount to 1.2-1.5 kcal mol-1, while the analogous estimates obtained for the gas-phase charged species [Emim][BF4]2- and [Emim]2[BF4]+ increase to 3.6-3.9 kcal mol-1.
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Affiliation(s)
- Sergey A Katsyuba
- Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Centre of RAS, Arbuzov st. 8, 420088, Kazan, Russia.
| | - Elena E Zvereva
- Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Centre of RAS, Arbuzov st. 8, 420088, Kazan, Russia. .,IFP Energies Nouvelles, 1 et 4 avenue de Bois-Préau, 92852 Rueil-Malmaison Cedex, France
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Chen L, Bryantsev VS. A density functional theory based approach for predicting melting points of ionic liquids. Phys Chem Chem Phys 2018; 19:4114-4124. [PMID: 28111666 DOI: 10.1039/c6cp08403f] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Accurate prediction of melting points of ILs is important both from the fundamental point of view and from the practical perspective for screening ILs with low melting points and broadening their utilization in a wider temperature range. In this work, we present an ab initio approach to calculate melting points of ILs with known crystal structures and illustrate its application for a series of 11 ILs containing imidazolium/pyrrolidinium cations and halide/polyatomic fluoro-containing anions. The melting point is determined as a temperature at which the Gibbs free energy of fusion is zero. The Gibbs free energy of fusion can be expressed through the use of the Born-Fajans-Haber cycle via the lattice free energy of forming a solid IL from gaseous phase ions and the sum of the solvation free energies of ions comprising IL. Dispersion-corrected density functional theory (DFT) involving (semi)local (PBE-D3) and hybrid exchange-correlation (HSE06-D3) functionals is applied to estimate the lattice enthalpy, entropy, and free energy. The ions solvation free energies are calculated with the SMD-generic-IL solvation model at the M06-2X/6-31+G(d) level of theory under standard conditions. The melting points of ILs computed with the HSE06-D3 functional are in good agreement with the experimental data, with a mean absolute error of 30.5 K and a mean relative error of 8.5%. The model is capable of accurately reproducing the trends in melting points upon variation of alkyl substituents in organic cations and replacement one anion by another. The results verify that the lattice energies of ILs containing polyatomic fluoro-containing anions can be approximated reasonably well using the volume-based thermodynamic approach. However, there is no correlation of the computed lattice energies with molecular volume for ILs containing halide anions. Moreover, entropies of solid ILs follow two different linear relationships with molecular volume for halides and polyatomic fluoro-containing anions. Continuous progress in predicting crystal structures of organic salts with halide anions will be a key factor for successful prediction of melting points with no prior knowledge of the crystal structure.
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Affiliation(s)
- Lihua Chen
- Department of Materials Science and Engineering, University of Connecticut, Storrs, CT 06269, USA and Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
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Basicity Characterization of Imidazolyl Ionic Liquids and Their Application for Biomass Dissolution. INTERNATIONAL JOURNAL OF CHEMICAL ENGINEERING 2018. [DOI: 10.1155/2018/7501659] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Alkalinity determination is of crucial significance for the applications of basic ionic liquids with imidazolyl. In this work, the ionization constant pKb value and acid function H- values of ionic liquids synthesized were calculated by pH method and UV spectrum-Hammett method. The dissolution ratio of biomass in these ionic liquids was measured at different temperatures. Finally, the relationship between the alkalinity and structure of these ionic liquids was discussed, and the relationship between the alkalinity of ionic liquid and the dissolution mechanism biomass was also discussed. The results show that the basicity of carboxylate ionic liquids is determined mainly by their anions, whereas cations take some finely tuned roles. Furthermore, cations and anions are equally important and are involved in dissolution mechanisms.
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Serra PB, Ribeiro FM, Rocha MA, Fulem M, Růžička K, Coutinho JA, Santos LM. Solid-liquid equilibrium and heat capacity trend in the alkylimidazolium PF6 series. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2017.10.042] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Rezabal E, Schäfer T. Ionic liquids as solvents of polar and non-polar solutes: affinity and coordination. Phys Chem Chem Phys 2015; 17:14588-97. [DOI: 10.1039/c5cp01774b] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Evolution of H2O and CO2 interactions with an ionic liquid (IL) from gas phase to IL phase is described. Affinity is lost and coordination patterns vary in the process, favouring H2O–anion and CO2–cation interactions.
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Affiliation(s)
- Elixabete Rezabal
- Laboratoire de Chimie Moleculaire
- Department of Chemistry
- Ecole Polytechnique and CNRS
- 91128 Palaiseau Cedex
- France
| | - Thomas Schäfer
- POLYMAT
- University of the Basque Country UPV/EHU 20018 Donostia-San Sebastián
- Spain
- Ikerbasque
- Basque Foundation for Science
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Fei Z, Zhu DR, Yan N, Scopelliti R, Katsuba SA, Laurenczy G, Chisholm DM, McIndoe JS, Seddon KR, Dyson PJ. Electrostatic and Non-covalent Interactions in Dicationic Imidazolium-Sulfonium Salts with Mixed Anions. Chemistry 2014; 20:4273-83. [DOI: 10.1002/chem.201303520] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 01/09/2014] [Indexed: 11/05/2022]
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Shah HH, Al-Balushi RA, Al-Suti MK, Khan MS, Marken F, Sudlow AL, Kociok-Köhn G, Woodall CH, Raithby PR, Molloy KC. New di-ferrocenyl-ethynylpyridinyl triphenylphosphine copper halide complexes and related di-ferricenyl electro-crystallized materials. Dalton Trans 2014; 43:9497-507. [PMID: 24824939 DOI: 10.1039/c3dt52914b] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Three di-ferrocenyl-ethynylpyridinyl copper complexes have been synthesised and CV measurements made.
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Affiliation(s)
- Hakikulla H. Shah
- Department of Chemistry
- Sultan Qaboos University
- Al-Khoudh 123, Sultanate of Oman
| | - Rayya A. Al-Balushi
- Department of Chemistry
- Sultan Qaboos University
- Al-Khoudh 123, Sultanate of Oman
| | - Mohammed K. Al-Suti
- Department of Chemistry
- Sultan Qaboos University
- Al-Khoudh 123, Sultanate of Oman
| | - Muhammad S. Khan
- Department of Chemistry
- Sultan Qaboos University
- Al-Khoudh 123, Sultanate of Oman
| | - Frank Marken
- Department of Chemistry
- University of Bath
- Bath, UK
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Katsyuba SA, Vener MV, Zvereva EE, Fei Z, Scopelliti R, Laurenczy G, Yan N, Paunescu E, Dyson PJ. How strong is hydrogen bonding in ionic liquids? Combined X-ray crystallographic, infrared/Raman spectroscopic, and density functional theory study. J Phys Chem B 2013; 117:9094-105. [PMID: 23822750 DOI: 10.1021/jp405255w] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Hydrogen bonding in ionic liquids based on the 1-(2'-hydroxylethyl)-3-methylimidazolium cation ([C₂OHmim](+)) and various anions ([A](-)) of differing H-bond acceptor strength, viz. hexafluorophosphate [PF6](-), tetrafluoroborate [BF₄](-), bis(trifluoromethanesulfonimide) [Tf₂N](-), trifluoromethylsulfonate [OTf](-), and trifluoroacetate [TFA](-), was studied by a range of spectroscopic and computational techniques and, in the case of [C₂OHmim][PF6], by single crystal X-ray diffraction. The first quantitative estimates of the energy (E(HB)) and the enthalpy (-ΔH(HB)) of H-bonds in bulk ILs were obtained from a theoretical analysis of the solid-state electron-density map of crystalline [C₂OHmim][PF6] and an analysis of the IR spectra in crystal and liquid samples. E(HB) for OH···[PF6](-) H-bonds amounts to ~3.4-3.8 kcal·mol(-1), whereas weaker H-bonds (2.8-3.1 kcal·mol(-1)) are formed between aromatic C2H group of imidazolium ring and the [PF6](-) anion. The enthalpy of the OH···[A](-) H-bonds follows the order: [PF6] (2.4 kcal·mol(-1)) < [BF₄] (3.3 kcal·mol(-1)) < [Tf₂N] (3.4 kcal·mol(-1)) < [OTf] (4.7 kcal·mol(-1)l) < [TFA] (6.2 kcal·mol(-1)). The formation of aggregates of self-associated [C₂OHmim](+) cations is present in liquid [C₂OHmim][PF6], [C₂OHmim][BF₄], and [C₂OHmim][Tf₂N], with the energy of the OH···OH H-bonds amounting to ~6 kcal·mol(-1). Multiple secondary interactions in the bulk ILs influence their structure, vibrational spectra, and H-bond strength. In particular, these interactions can blue-shift the stretching frequencies of the CH groups of the imidazolium ring in spite of red-shifting CH···[A](-) H-bonds. They also weaken the H-bonding in the IL relative to the isolated ion pairs, with these anticooperative effects amounting to ca. 50% of the E(HB) value.
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Affiliation(s)
- Sergey A Katsyuba
- A. E. Arbuzov Institute of Organic and Physical Chemistry of Kazan Scientific Centre of the Russian Academy of Sciences, Arbuzov str. 8, 420088 Kazan, Russia.
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Relationship between stabilization energy and thermophysical properties of different imidazolium ionic liquids: DFT studies. COMPUT THEOR CHEM 2013. [DOI: 10.1016/j.comptc.2013.04.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Rezabal E, Schäfer T. First Principle Approach to Solvation by Methylimidazolium-Based Ionic Liquids. J Phys Chem B 2013; 117:553-62. [DOI: 10.1021/jp305379s] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Elixabete Rezabal
- POLYMAT, University of the Basque Country UPV/EHU, 20018 Donostia-San Sebastián,
Spain
| | - Thomas Schäfer
- POLYMAT, University of the Basque Country UPV/EHU, 20018 Donostia-San Sebastián,
Spain
- IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain
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Katsyuba SA, Zvereva EE, Yan N, Yuan X, Kou Y, Dyson PJ. Rationalization of Solvation and Stabilization of Palladium Nanoparticles in Imidazolium-Based Ionic Liquids by DFT and Vibrational Spectroscopy. Chemphyschem 2012; 13:1781-90. [DOI: 10.1002/cphc.201200087] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Indexed: 11/08/2022]
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Endo T, Imanari M, Seki H, Nishikawa K. Effects of Methylation at Position 2 of Cation Ring on Rotational Dynamics of Imidazolium-Based Ionic Liquids Investigated by NMR Spectroscopy: [C4mim]Br vs [C4C1mim]Br. J Phys Chem A 2011; 115:2999-3005. [DOI: 10.1021/jp200635h] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Takatsugu Endo
- Graduate School of Advanced Integration Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
| | - Mamoru Imanari
- Chemical Analysis Center, Chiba University, Yayoi, Inage-ku, Chiba 263-8522, Japan
| | - Hiroko Seki
- Chemical Analysis Center, Chiba University, Yayoi, Inage-ku, Chiba 263-8522, Japan
| | - Keiko Nishikawa
- Graduate School of Advanced Integration Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
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