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Rauber D, Philippi F, Becker J, Zapp J, Morgenstern B, Kuttich B, Kraus T, Hempelmann R, Hunt P, Welton T, Kay CWM. Anion and ether group influence in protic guanidinium ionic liquids. Phys Chem Chem Phys 2023; 25:6436-6453. [PMID: 36779955 DOI: 10.1039/d2cp05724g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Ionic liquids are attractive liquid materials for many advanced applications. For targeted design, in-depth knowledge about their structure-property-relations is urgently needed. We prepared a set of novel protic ionic liquids (PILs) with a guanidinium cation with either an ether or alkyl side chain and different anions. While being a promising cation class, the available data is insufficient to guide design. We measured thermal and transport properties, nuclear magnetic resonance (NMR) spectra as well as liquid and crystalline structures supported by ab initio computations and were able to obtain a detailed insight into the influence of the anion and the ether substitution on the physical and spectroscopic properties. For the PILs, hydrogen bonding is the main interaction between cation and anion and the H-bond strength is inversely related to the proton affinity of the constituting acid and correlated to the increase of 1H and 15N chemical shifts. Using anions from acids with lower proton affinity leads to proton localization on the cation as evident from NMR spectra and self-diffusion coefficients. In contrast, proton exchange was evident in ionic liquids with triflate and trifluoroacetate anions. Using imide-type anions and ether side groups decreases glass transitions as well as fragility, and accelerated dynamics significantly. In case of the ether guanidinium ionic liquids, the conformation of the side chain adopts a curled structure as the result of dispersion interactions, while the alkyl chains prefer a linear arrangement.
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Affiliation(s)
- Daniel Rauber
- Department of Chemistry, Saarland University, Campus B 2.2, 66123 Saarbrücken, Germany.
| | - Frederik Philippi
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, White City Campus, London W12 0BZ, UK
| | - Julian Becker
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, White City Campus, London W12 0BZ, UK
| | - Josef Zapp
- Pharmaceutical Biology, Saarland University, Campus B 2.3, 66123 Saarbrücken, Germany
| | - Bernd Morgenstern
- Department of Chemistry, Saarland University, Campus B 2.2, 66123 Saarbrücken, Germany.
| | - Björn Kuttich
- INM-Leibniz Institute for New Materials, Campus D2.2, 66123 Saarbrücken, Germany
| | - Tobias Kraus
- Department of Chemistry, Saarland University, Campus B 2.2, 66123 Saarbrücken, Germany. .,INM-Leibniz Institute for New Materials, Campus D2.2, 66123 Saarbrücken, Germany
| | - Rolf Hempelmann
- Department of Chemistry, Saarland University, Campus B 2.2, 66123 Saarbrücken, Germany.
| | - Patricia Hunt
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, White City Campus, London W12 0BZ, UK.,School of Chemical and Physical Sciences, Victoria University of Wellington, New Zealand
| | - Tom Welton
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, White City Campus, London W12 0BZ, UK
| | - Christopher W M Kay
- Department of Chemistry, Saarland University, Campus B 2.2, 66123 Saarbrücken, Germany. .,London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London WC1H 0AH, UK.
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Imamura K, Yokogawa D, Higashi M, Sato H. Reference interaction site model self-consistent field with constrained spatial electron density approach for nuclear magnetic shielding in solution. J Chem Phys 2022; 157:204105. [DOI: 10.1063/5.0122326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
We propose a new hybrid approach combining quantum chemistry and statistical mechanics of liquids for calculating the nuclear magnetic resonance (NMR) chemical shifts of solvated molecules. Based on the reference interaction site model self-consistent field with constrained spatial electron density distribution (RISM–SCF–cSED) method, the electronic structure of molecules in solution is obtained, and the expression for the nuclear magnetic shielding tensor is derived as the second-order derivative of the Helmholtz energy of the solution system. We implemented a method for calculating chemical shifts and applied it to an adenine molecule in water, where hydrogen bonding plays a crucial role in electronic and solvation structures. We also performed the calculations of 17O chemical shifts, which showed remarkable solvent dependence. While converged results could not be sometimes obtained using the conventional method, in the present framework with RISM–SCF–cSED, an adequate representation of electron density is guaranteed, making it possible to obtain an NMR shielding constant stably. This introduction of cSED is key to extending the method’s applicability to obtain the chemical shift of various chemical species. The present demonstration illustrates our approach’s superiority in terms of numerical robustness and accuracy.
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Affiliation(s)
- Kosuke Imamura
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Daisuke Yokogawa
- Graduate School of Arts and Science, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan
| | - Masahiro Higashi
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Hirofumi Sato
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
- Fukui Institute for Fundamental Chemistry, Kyoto University, Kyoto 606-8103, Japan
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Damodaran K. Recent advances in NMR spectroscopy of ionic liquids. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2022; 129:1-27. [PMID: 35292132 DOI: 10.1016/j.pnmrs.2021.12.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 12/17/2021] [Accepted: 12/28/2021] [Indexed: 06/14/2023]
Abstract
This review presents recent developments in the application of NMR spectroscopic techniques in the study of ionic liquids. NMR has been the primary tool not only for the structural characterization of ionic liquids, but also for the study of dynamics. The presence of a host of NMR active nuclei in ionic liquids permits widespread use of multinuclear NMR experiments. Chemical shifts and multinuclear coupling constants are used routinely for the structure elucidation of ionic liquids and of products formed by their covalent interactions with other materials. Also, the availability of a multitude of NMR techniques has facilitated the study of dynamical processes in them. These include the use of NOESY to study inter-ionic interactions, pulsed-field gradient techniques for probing transport properties, and relaxation measurements to elucidate rotational dynamics. This review will focus on the application of each of these techniques to investigate ionic liquids.
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Affiliation(s)
- Krishnan Damodaran
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, United States.
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Shmukler L, Fedorova I, Fadeeva YA, Safonova L. The physicochemical properties and structure of alkylammonium protic ionic liquids of RnH4-nNX (n = 1–3) family. A mini–review. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.114350] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Overbeck V, Schröder H, Bonsa AM, Neymeyr K, Ludwig R. Insights into the translational and rotational dynamics of cations and anions in protic ionic liquids by means of NMR fast-field-cycling relaxometry. Phys Chem Chem Phys 2021; 23:2663-2675. [PMID: 33480888 DOI: 10.1039/d0cp05440b] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Understanding the translational and rotational dynamics of cations and anions in hydrogen bonded protic ionic liquids (PIls) is still a challenge. In this study, we determine self-diffusion coefficients and rotational correlation times of both ions in triethylammonium based PILs by means of NMR Fast-Field-Cycling (FFC) relaxometry. Global fits of 1H and 19F nuclear magnetic relaxation dispersion (NMRD) curves allowed proper separation into intra and inter molecular relaxation rates for both NMR sensitive nuclei and thus a reliable description of translational and rotational motion for both ions individually. The diffusion coefficients of the cations are in the order of 6 × 10-11 m2 s-1 at room temperature and about 50 per cent larger than those of the anions. The diffusion coefficients of cations and anions in both PILs were compared with those we derived from applying an universal dispersion power law and those known from pulsed field gradient (PFG) NMR studies. Considering the Nernst-Einstein equation, molar conductivities were calculated from cationic and anionic diffusion coefficients and related to directly measured molar conductivities, allowing the determination of the degree of dissociation. The rotational correlation times τR ranging from 50 ps up to 2 ns as a function of temperature were compared with those obtained from high-field NMR quadrupolar relaxation time measurements addressing explicitly the rotation of the NH vector and giving insights into the acidic proton mobility. The Stokes-Einstein and Stokes-Einstein-Debye relations were applied to relate the diffusion coefficients and rotational correlation times to the macroscopic bulk viscosity. The results were also discussed with respect to the archetypical PIL ethylammonium nitrate.
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Affiliation(s)
- Viviane Overbeck
- Department LL&M, University of Rostock, Albert-Einstein-Str. 25, 18059 Rostock, Germany. and Physical and Theoretical Chemistry, Department of Chemistry, University of Rostock, Dr-Lorenz-Weg 2, 18059 Rostock, Germany
| | - Henning Schröder
- Department of Mathematics, University of Rostock, Ulmenstr. 69, 18057 Rostock, Germany
| | - Anne-Marie Bonsa
- Department LL&M, University of Rostock, Albert-Einstein-Str. 25, 18059 Rostock, Germany. and Physical and Theoretical Chemistry, Department of Chemistry, University of Rostock, Dr-Lorenz-Weg 2, 18059 Rostock, Germany
| | - Klaus Neymeyr
- Department of Mathematics, University of Rostock, Ulmenstr. 69, 18057 Rostock, Germany
| | - Ralf Ludwig
- Department LL&M, University of Rostock, Albert-Einstein-Str. 25, 18059 Rostock, Germany. and Physical and Theoretical Chemistry, Department of Chemistry, University of Rostock, Dr-Lorenz-Weg 2, 18059 Rostock, Germany and Leibniz Institute for Catalysis e.V., Albert-Einstein-Str. 29a, 18059 Rostock, Germany
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Fedorova IV, Safonova LP. Ion Pair Structures and Hydrogen Bonding in R nNH 4-n Alkylammonium Ionic Liquids with Hydrogen Sulfate and Mesylate Anions by DFT Computations. J Phys Chem A 2020; 124:3170-3179. [PMID: 32243166 DOI: 10.1021/acs.jpca.0c01282] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Density function theory calculations are employed to study the interaction of amines bearing different numbers of alkyl substituents of different sizes on the nitrogen atom with sulfuric and methanesulfonic acids. The proton affinities of the studied amines are calculated, and it is shown that the higher the value is, the more probable is its protonation. The most stable structures of the ion pairs resulting from the acid-base interaction are obtained and characterized. The geometric parameters of the ion pairs and the characteristics derived from the NBO and QTAIM analysis show that there are hydrogen bonding interactions between the cation and the anion. The hydrogen bonding character of the ion pairs and the strength of the interaction between the ions strongly depend on the nature of the cation itself. The interaction between the ions in the ion pairs weakens with the increase in the cation size. The trend of change in the structural parameters of the H-bonds and energetic characteristics in the cation series for the studied ion pairs is not dependent on the nature of the anion.
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Affiliation(s)
- Irina V Fedorova
- G. A. Krestov Institute of Solution Chemistry of the Russian Academy of Sciences, 1 Akademicheskaya Street, Ivanovo 153045, Russia
| | - Lyubov P Safonova
- G. A. Krestov Institute of Solution Chemistry of the Russian Academy of Sciences, 1 Akademicheskaya Street, Ivanovo 153045, Russia
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Fedotova MV, Kruchinin SE, Chuev GN. Features of local ordering of biocompatible ionic liquids: The case of choline-based amino acid ionic liquids. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.112081] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Shmukler LE, Fedorova IV, Gruzdev MS, Safonova LP. Triethylamine-Based Salts: Protic Ionic Liquids or Molecular Complexes? J Phys Chem B 2019; 123:10794-10806. [DOI: 10.1021/acs.jpcb.9b08032] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- L. E. Shmukler
- G. A. Krestov Institute of Solution Chemistry, Russian Academy of Sciences, Akademicheskaya St. 1, Ivanovo, 153045, Russia
| | - I. V. Fedorova
- G. A. Krestov Institute of Solution Chemistry, Russian Academy of Sciences, Akademicheskaya St. 1, Ivanovo, 153045, Russia
| | - M. S. Gruzdev
- G. A. Krestov Institute of Solution Chemistry, Russian Academy of Sciences, Akademicheskaya St. 1, Ivanovo, 153045, Russia
| | - L. P. Safonova
- G. A. Krestov Institute of Solution Chemistry, Russian Academy of Sciences, Akademicheskaya St. 1, Ivanovo, 153045, Russia
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Gabriele F, Chiarini M, Germani R, Tiecco M, Spreti N. Effect of water addition on choline chloride/glycol deep eutectic solvents: Characterization of their structural and physicochemical properties. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.111301] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Turguła A, Materna K, Gwiazdowska D, Walkiewicz F, Marcinkowska K, Pernak J. Difunctional ammonium ionic liquids with bicyclic cations. NEW J CHEM 2019. [DOI: 10.1039/c8nj06054a] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The increasing limitations regarding the applied amounts of plant protection make hybrid ionic liquids an interesting class of compounds belonging to the III generation ILs.
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Affiliation(s)
- Anna Turguła
- Department of Chemical Technology
- Poznan University of Technology
- Poznan 60-965
- Poland
| | - Katarzyna Materna
- Department of Chemical Technology
- Poznan University of Technology
- Poznan 60-965
- Poland
| | - Daniela Gwiazdowska
- Department of Natural Science and Quality Assurance
- Poznan University of Economics and Business
- Poland
| | - Filip Walkiewicz
- Department of Chemical Technology
- Poznan University of Technology
- Poznan 60-965
- Poland
| | | | - Juliusz Pernak
- Department of Chemical Technology
- Poznan University of Technology
- Poznan 60-965
- Poland
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Saielli G. Computational Spectroscopy of Ionic Liquids for Bulk Structure Elucidation. ADVANCED THEORY AND SIMULATIONS 2018. [DOI: 10.1002/adts.201800084] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Giacomo Saielli
- CNR Institute on Membrane Technology; Unit of Padova; Via Marzolo 1-35131 Padova Italy
- Department of Chemical Sciences; University of Padova; Via Marzolo 1-35131 Padova Italy
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