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Abe H, Yoshiichi Y, Hirano T, Ohkubo T, Kishimura H. Hydrogen bonding of nanoconfined water in ionic liquids. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Estimation of the slow hydrogen–deuterium exchange rates for local water confined in 1-butyl-3-methylimidazolium tetrafluoroborate via nuclear magnetic resonance. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Abe H, Yoshiichi Y, Kishimura H. Hydrogen/deuterium Exchange in 1-Alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide-based Solutions. Chem Phys 2022. [DOI: 10.1016/j.chemphys.2022.111631] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Li J, Farooq MQ, Petrich JW, Anderson JL, Smith EA. Fast and non-destructive determination of water content in ionic liquids at varying temperatures by Raman spectroscopy and multivariate regression analysis. Anal Chim Acta 2021; 1188:339164. [PMID: 34794575 DOI: 10.1016/j.aca.2021.339164] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 10/06/2021] [Accepted: 10/08/2021] [Indexed: 11/26/2022]
Abstract
Imidazolium acetate ionic liquids (ILs) have been utilized as promising solvents in many applications that involve varying water content and temperature. These experimental variables affect the anion-cation intermolecular interactions, which in turn influence the performance of the ILs in these applications. This paper shows Raman spectroscopy can be used as an operando method to measure water content in IL solvents when simultaneous temperature changes may occur. The Raman spectra of 1-alkyl-3-methylimidazolium acetate ILs (alkyl chain length n = 2, 4, 6, 8) with varying water content (from 0.028 to 0.899 water mole fraction) and temperature (from 78.1 K to 423.1 K) were measured. Increasing the water content or decreasing the temperature of the tested ILs weakens the anion-cation intermolecular interactions. The water content of these ILs can be quantified even in conditions when the temperature is changing using Raman spectroscopy combined with multivariate regression analysis, including principal component regression (PCR), partial-least-squares regression (PLSR), and artificial neural networks (ANNs). The ANN model combined with partial-least-squares (PLS) achieved the highest prediction accuracy of water content in ILs at varying temperatures (RMSECV = 0.017, R2CV = 99.1%, RMSEP = 0.019, R2P = 98.8%, RPD = 8.93). Raman spectroscopy provides a potential fast non-destructive operando method to monitor the water content of ILs even in applications when the temperature may be simultaneously altered; this information can lead to the optimized use of these ILs in many applications.
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Affiliation(s)
- Jingzhe Li
- The Ames Laboratory, U.S. Department of Energy, Ames, IA, 50011-3111, United States; Department of Chemistry, Iowa State University, Ames, IA, 50011-3111, United States
| | - Muhammad Qamar Farooq
- The Ames Laboratory, U.S. Department of Energy, Ames, IA, 50011-3111, United States; Department of Chemistry, Iowa State University, Ames, IA, 50011-3111, United States
| | - Jacob W Petrich
- The Ames Laboratory, U.S. Department of Energy, Ames, IA, 50011-3111, United States; Department of Chemistry, Iowa State University, Ames, IA, 50011-3111, United States
| | - Jared L Anderson
- The Ames Laboratory, U.S. Department of Energy, Ames, IA, 50011-3111, United States; Department of Chemistry, Iowa State University, Ames, IA, 50011-3111, United States
| | - Emily A Smith
- The Ames Laboratory, U.S. Department of Energy, Ames, IA, 50011-3111, United States; Department of Chemistry, Iowa State University, Ames, IA, 50011-3111, United States.
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Pabst F, Kraus J, Kloth S, Steinrücken E, Kruteva M, Radulescu A, Vogel M, Blochowicz T. Evidence of supercoolable nanoscale water clusters in an amorphous ionic liquid matrix. J Chem Phys 2021; 155:174501. [PMID: 34742203 DOI: 10.1063/5.0066180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Nanoscale water clusters in an ionic liquid matrix, also called "water pockets," were previously found in some mixtures of water with ionic liquids containing hydrophilic anions. However, in these systems, at least partial crystallization occurs upon supercooling. In this work, we show for mixtures of 1-butyl-3-methylimidazolium dicyanamide with water that none of the components crystallizes up to a water content of 72 mol. %. The dynamics of the ionic liquid matrix is monitored from above room temperature down to the glass transition by combining depolarized dynamic light scattering with broadband dielectric and nuclear magnetic resonance spectroscopy, revealing that the matrix behaves like a common glass former and stays amorphous in the whole temperature range. Moreover, we demonstrate by a combination of Raman spectroscopy, small angle neutron scattering, and molecular dynamics simulation that, indeed, nanoscale water clusters exist in this mixture.
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Affiliation(s)
- Florian Pabst
- TU Darmstadt, Institute for Condensed Matter Physics, 64289 Darmstadt, Germany
| | - Jennifer Kraus
- TU Darmstadt, Institute for Condensed Matter Physics, 64289 Darmstadt, Germany
| | - Sebastian Kloth
- TU Darmstadt, Institute for Condensed Matter Physics, 64289 Darmstadt, Germany
| | - Elisa Steinrücken
- TU Darmstadt, Institute for Condensed Matter Physics, 64289 Darmstadt, Germany
| | - Margarita Kruteva
- Jülich Centre for Neutron Science JCNS (JCNS-1), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Aurel Radulescu
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, 85747 Garching, Germany
| | - Michael Vogel
- TU Darmstadt, Institute for Condensed Matter Physics, 64289 Darmstadt, Germany
| | - Thomas Blochowicz
- TU Darmstadt, Institute for Condensed Matter Physics, 64289 Darmstadt, Germany
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Silva W, Zanatta M, Ferreira AS, Corvo MC, Cabrita EJ. Revisiting Ionic Liquid Structure-Property Relationship: A Critical Analysis. Int J Mol Sci 2020; 21:ijms21207745. [PMID: 33086771 PMCID: PMC7589445 DOI: 10.3390/ijms21207745] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 10/15/2020] [Accepted: 10/16/2020] [Indexed: 12/23/2022] Open
Abstract
In the last few years, ionic liquids (ILs) have been the focus of extensive studies concerning the relationship between structure and properties and how this impacts their application. Despite a large number of studies, several topics remain controversial or not fully answered, such as: the existence of ion pairs, the concept of free volume and the effect of water and its implications in the modulation of ILs physicochemical properties. In this paper, we present a critical review of state-of-the-art literature regarding structure–property relationship of ILs, we re-examine analytical theories on the structure–property correlations and present new perspectives based on the existing data. The interrelation between transport properties (viscosity, diffusion, conductivity) of IL structure and free volume are analysed and discussed at a molecular level. In addition, we demonstrate how the analysis of microscopic features (particularly using NMR-derived data) can be used to explain and predict macroscopic properties, reaching new perspectives on the properties and application of ILs.
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Affiliation(s)
- Wagner Silva
- UCIBIO, Chemistry Department, School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal; (W.S.); (A.S.F.)
| | - Marcileia Zanatta
- i3N|Cenimat, Materials Science Department, School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal; (M.Z.); (M.C.C.)
| | - Ana Sofia Ferreira
- UCIBIO, Chemistry Department, School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal; (W.S.); (A.S.F.)
| | - Marta C. Corvo
- i3N|Cenimat, Materials Science Department, School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal; (M.Z.); (M.C.C.)
| | - Eurico J. Cabrita
- UCIBIO, Chemistry Department, School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal; (W.S.); (A.S.F.)
- Correspondence:
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Yoshimura Y, Mori T, Kaneko K, Hattori S, Takekiyo T, Masuda Y, Shimizu A. Raman investigation on the local structure of alcohols in 1-butyl-3-methylimidazolium tetrafluoroborate. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.111508] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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