1
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Yao B, Alvarez VM, Paluch M, Fedor G, McLaughlin S, McGrogan A, Swadźba-Kwaśny M, Wojnarowska Z. Crystallization Kinetics of Phosphonium Ionic Liquids: Effect of Cation Alkyl Chain Length and Thermal History. J Phys Chem B 2024; 128:6610-6621. [PMID: 38924509 PMCID: PMC11247483 DOI: 10.1021/acs.jpcb.4c01720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 06/13/2024] [Accepted: 06/14/2024] [Indexed: 06/28/2024]
Abstract
The effects of alkyl chain length on the crystallization kinetics and ion mobility of tetraalkylphosphonium, [P666,n][TFSI], (n = 2, 6, 8, and 12) ionic liquids were studied by differential scanning calorimetry (DSC) and broadband dielectric spectroscopy (BDS) over a wide temperature range. The liquid-glass transition temperature (Tg) and ion dynamics examined over a broad T range were almost insensitive to structural modifications of the phosphonium cation. In contrast, the crystallization kinetics were strongly affected by the length of the fourth alkyl chain. Furthermore, the thermal history of the sample (cold vs melt crystallization) significantly impacted the crystallization rate. It has been found that the nature of crystallization phenomena is the same across the homologous series, while the kinetic aspect differs. Finally, electric conductivity in supercooled liquid and crystalline solid phases was measured for all samples, revealing significant ionic conductivity, largely independent of the cation structure.
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Affiliation(s)
- B. Yao
- Institute
of Physics, The University of Silesia in
Katowice, 75 Pułku Piechoty 1A, Chorzów 41-500, Poland
| | - V. Morales Alvarez
- Institute
of Physics, The University of Silesia in
Katowice, 75 Pułku Piechoty 1A, Chorzów 41-500, Poland
| | - M. Paluch
- Institute
of Physics, The University of Silesia in
Katowice, 75 Pułku Piechoty 1A, Chorzów 41-500, Poland
| | - G. Fedor
- The
QUILL Research Centre, School of Chemistry and Chemical Engineering, The Queen’s University of Belfast, David Keir Building, Stranmillis
Rd, Belfast, NI BT9 5AG, U.K.
| | - S. McLaughlin
- The
QUILL Research Centre, School of Chemistry and Chemical Engineering, The Queen’s University of Belfast, David Keir Building, Stranmillis
Rd, Belfast, NI BT9 5AG, U.K.
| | - A. McGrogan
- The
QUILL Research Centre, School of Chemistry and Chemical Engineering, The Queen’s University of Belfast, David Keir Building, Stranmillis
Rd, Belfast, NI BT9 5AG, U.K.
| | - M. Swadźba-Kwaśny
- The
QUILL Research Centre, School of Chemistry and Chemical Engineering, The Queen’s University of Belfast, David Keir Building, Stranmillis
Rd, Belfast, NI BT9 5AG, U.K.
| | - Z. Wojnarowska
- Institute
of Physics, The University of Silesia in
Katowice, 75 Pułku Piechoty 1A, Chorzów 41-500, Poland
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2
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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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3
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Arkhipova EA, Ivanov AS, Levin MM, Maslakov KI, Kupreenko SY, Savilov SV. Study of tetraalkylammonium salts in acetonitrile solutions: Transport properties, density, thermal expansion and phase transitions. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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4
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Hofmann A, Rauber D, Wang TM, Hempelmann R, Kay CWM, Hanemann T. Novel Phosphonium-Based Ionic Liquid Electrolytes for Battery Applications. Molecules 2022; 27:molecules27154729. [PMID: 35897904 PMCID: PMC9329924 DOI: 10.3390/molecules27154729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 07/21/2022] [Accepted: 07/21/2022] [Indexed: 02/04/2023] Open
Abstract
In this study, we address the fundamental question of the physicochemical and electrochemical properties of phosphonium-based ionic liquids containing the counter-ions bis(trifluoromethanesulfonyl)imide ([TFSI]−) and bis(fluorosulfonyl)imide ([FSI]−). To clarify these structure–property as well as structure–activity relationships, trimethyl-based alkyl- and ether-containing phosphonium ILs were systematically synthesized, and their properties, namely density, flow characteristics, alkali metal compatibility, oxidative stability, aluminum corrosivity as well as their use in Li-ion cells were examined comprehensively. The variable moiety on the phosphonium cation exhibited a chain length of four and five, respectively. The properties were discussed as a function of the side chain, counter-ion and salt addition ([Li][TFSI] or [Li][FSI]). High stability coupled with good flow characteristics were found for the phosphonium IL [P1114][TFSI] and the mixture [P1114][TFSI] + [Li][TFSI], respectively.
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Affiliation(s)
- Andreas Hofmann
- Institute for Applied Materials, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany; (T.-M.W.); (T.H.)
- Correspondence: ; Tel.: +49-721-608-25920
| | - Daniel Rauber
- Department of Chemistry, Saarland University, Campus B2.2, 66123 Saarbrücken, Germany; (D.R.); (R.H.); (C.W.M.K.)
| | - Tzu-Ming Wang
- Institute for Applied Materials, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany; (T.-M.W.); (T.H.)
| | - Rolf Hempelmann
- Department of Chemistry, Saarland University, Campus B2.2, 66123 Saarbrücken, Germany; (D.R.); (R.H.); (C.W.M.K.)
| | - Christopher W. M. Kay
- Department of Chemistry, Saarland University, Campus B2.2, 66123 Saarbrücken, Germany; (D.R.); (R.H.); (C.W.M.K.)
- London Centre for Nanotechnology, Bloomsbury Campus, University College London, 17-19 Gordon Street, London WC1H 0AH, UK
| | - Thomas Hanemann
- Institute for Applied Materials, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany; (T.-M.W.); (T.H.)
- Department of Microsystems Engineering, University of Freiburg, Georges-Köhler-Allee 102, D-79110 Freiburg, Germany
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5
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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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6
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Philippi F, Rauber D, Eliasen KL, Bouscharain N, Niss K, Kay CWM, Welton T. Pressing matter: why are ionic liquids so viscous? Chem Sci 2022; 13:2735-2743. [PMID: 35340854 PMCID: PMC8890108 DOI: 10.1039/d1sc06857a] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 02/06/2022] [Indexed: 01/09/2023] Open
Abstract
Room temperature ionic liquids are considered to have huge potential for practical applications such as batteries. However, their high viscosity presents a significant challenge to their use changing from niche to ubiquitous. The modelling and prediction of viscosity in ionic liquids is the subject of an ongoing debate involving two competing hypotheses: molecular and local mechanisms versus collective and long-range mechanisms. To distinguish between these two theories, we compared an ionic liquid with its uncharged, isoelectronic, isostructural molecular mimic. We measured the viscosity of the molecular mimic at high pressure to emulate the high densities in ionic liquids, which result from the Coulomb interactions in the latter. We were thus able to reveal that the relative contributions of coulombic compaction and the charge network interactions are of similar magnitude. We therefore suggest that the optimisation of the viscosity in room temperature ionic liquids must follow a dual approach.
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Affiliation(s)
- Frederik Philippi
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London White City Campus London W12 0BZ UK
| | - Daniel Rauber
- Department of Chemistry, Saarland University Campus B2.2 Saarbrücken Germany
| | - Kira Lieberkind Eliasen
- "Glass and Time", IMFUFA, Department of Science and Environment, Roskilde University P.O. Box 260 DK-4000 Roskilde Denmark
| | | | - Kristine Niss
- "Glass and Time", IMFUFA, Department of Science and Environment, Roskilde University P.O. Box 260 DK-4000 Roskilde Denmark
| | - Christopher W M Kay
- Department of Chemistry, Saarland University Campus B2.2 Saarbrücken Germany.,London Centre for Nanotechnology, University College London 17-19 Gordon Street London WC1H 0AH UK
| | - Tom Welton
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London White City Campus London W12 0BZ UK
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7
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Xiao Y, Song F, An S, Zeng F, Xu Y, Peng C, Liu H. Quantitative structure-property relationship for predicting the diffusion coefficient of ionic liquids. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.118476] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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8
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Arkhipova EA, Ivanov AS, Reshetko SS, Aleshin DY, Maslakov KI, Kupreenko SY, Savilov SV. Transport properties of nitrile and carbonate solutions of [P66614][NTf 2] ionic liquid, its thermal degradation and non-isothermal kinetics of decomposition. Phys Chem Chem Phys 2021; 23:23909-23921. [PMID: 34651626 DOI: 10.1039/d1cp03549e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The electrical conductivity, density and diffusion coefficients of trihexyl(tetradecyl)phosphonium bis(trifluoromethylsulfonyl)amide ([P66614][NTf2]) ionic liquid and its binary solutions in acetonitrile, propionitrile, dimethyl and diethyl carbonates were measured in the temperature range of 293-348 K. The electrical conductivity - ionic liquid mole fraction dependencies for the binary solutions were fitted with the empirical Casteel-Amis equation. The temperature dependencies of electrical conductivity were analyzed using the Arrhenius, Litovitz and Vogel-Fulcher-Tammann approaches. The dependences of the Arrhenius activation energy and pre-exponential factor on the mole fraction of ionic liquid in the solutions were fitted with the empirical equations proposed in the literature. The thermo-gravimetric analysis combined with mass spectrometry demonstrated the high thermal stability of [P66614][NTf2] up to 600 K. At higher temperatures the decomposition of [P66614][NTf2] proceeded via the elimination of alkyl radicals as a result of the nucleophilic attack of reactive intermediates to the [P66614]+ cation with the formation of trialkylphosphines. The activation energies of the thermal destruction of [P66614][NTf2] were calculated using the Kissinger equation and non-linear integral isoconversional model.
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Affiliation(s)
- Ekaterina A Arkhipova
- Department of Chemistry, Lomonosov Moscow State University, 1-3 Leninskiye Gory, Moscow 119991, Russia.
| | - Anton S Ivanov
- Department of Chemistry, Lomonosov Moscow State University, 1-3 Leninskiye Gory, Moscow 119991, Russia.
| | - Sergei S Reshetko
- Department of Chemistry, Lomonosov Moscow State University, 1-3 Leninskiye Gory, Moscow 119991, Russia.
| | - Dmitry Yu Aleshin
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str., 28, Moscow 119991, Russia
| | - Konstantin I Maslakov
- Department of Chemistry, Lomonosov Moscow State University, 1-3 Leninskiye Gory, Moscow 119991, Russia.
| | - Stepan Yu Kupreenko
- Department of Chemistry, Lomonosov Moscow State University, 1-3 Leninskiye Gory, Moscow 119991, Russia.
| | - Serguei V Savilov
- Department of Chemistry, Lomonosov Moscow State University, 1-3 Leninskiye Gory, Moscow 119991, Russia.
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9
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Rauber D, Philippi F, Kuttich B, Becker J, Kraus T, Hunt P, Welton T, Hempelmann R, Kay CWM. Curled cation structures accelerate the dynamics of ionic liquids. Phys Chem Chem Phys 2021; 23:21042-21064. [PMID: 34522943 DOI: 10.1039/d1cp02889h] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ionic liquids are modern liquid materials with potential and actual implementation in many advanced technologies. They combine many favourable and modifiable properties but have a major inherent drawback compared to molecular liquids - slower dynamics. In previous studies we found that the dynamics of ionic liquids are significantly accelerated by the introduction of multiple ether side chains into the cations. However, the origin of the improved transport properties, whether as a result of the altered cation conformation or due to the absence of nanostructuring within the liquid as a result of the higher polarity of the ether chains, remained to be clarified. Therefore, we prepared two novel sets of methylammonium based ionic liquids; one set with three ether substituents and another set with three butyl side chains, in order to compare their dynamic properties and liquid structures. Using a range of anions, we show that the dynamics of the ether-substituted cations are systematically and distinctly accelerated. Liquefaction temperatures are lowered and fragilities increased, while at the same time cation-anion distances are slightly larger for the alkylated samples. Furthermore, pronounced liquid nanostructures were not observed. Molecular dynamics simulations demonstrate that the origin of the altered properties of the ether substituted ionic liquids is primarily due to a curled ether chain conformation, in contrast to the alkylated cations where the alkyl chains retain a linear conformation. Thus, the observed structure-property relations can be explained by changes in the geometric shape of the cations, rather than by the absence of a liquid nanostructure. Application of quantum chemical calculations to a simplified model system revealed that intramolecular hydrogen-bonding is responsible for approximately half of the stabilisation of the curled ether-cations, whereas the other half stems from non-specific long-range interactions. These findings give more detailed insights into the structure-property relations of ionic liquids and will guide the development of ionic liquids that do not suffer from slow dynamics.
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Affiliation(s)
- Daniel Rauber
- Department of Chemistry, Saarland University, Campus B2.2, 66123, Saarbrücken, Germany.
| | - Frederik Philippi
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, White City Campus, London W12 0BZ, UK
| | - Björn Kuttich
- INM-Leibniz Institute for New Materials, Campus D2.2, 66123, Saarbrücken, Germany
| | - Julian Becker
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, White City Campus, London W12 0BZ, UK
| | - Tobias Kraus
- Department of Chemistry, Saarland University, Campus B2.2, 66123, Saarbrücken, Germany. .,INM-Leibniz Institute for New Materials, Campus D2.2, 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
| | - Rolf Hempelmann
- Department of Chemistry, Saarland University, Campus B2.2, 66123, Saarbrücken, Germany.
| | - Christopher W M Kay
- Department of Chemistry, Saarland University, Campus B2.2, 66123, Saarbrücken, Germany. .,London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London WC1H 0AH, UK.
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10
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Lundin F, Hansen HW, Adrjanowicz K, Frick B, Rauber D, Hempelmann R, Shebanova O, Niss K, Matic A. Pressure and Temperature Dependence of Local Structure and Dynamics in an Ionic Liquid. J Phys Chem B 2021; 125:2719-2728. [PMID: 33656344 PMCID: PMC8034775 DOI: 10.1021/acs.jpcb.1c00147] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
![]()
A detailed understanding
of the local dynamics in ionic liquids
remains an important aspect in the design of new ionic liquids as
advanced functional fluids. Here, we use small-angle X-ray scattering
and quasi-elastic neutron spectroscopy to investigate the local structure
and dynamics in a model ionic liquid as a function of temperature
and pressure, with a particular focus on state points (P,T) where the macroscopic dynamics, i.e., conductivity,
is the same. Our results suggest that the initial step of ion transport
is a confined diffusion process, on the nanosecond timescale, where
the motion is restricted by a cage of nearest neighbors. This process
is invariant considering timescale, geometry, and the participation
ratio, at state points of constant conductivity, i.e., state points
of isoconductivity. The connection to the nearest-neighbor structure
is underlined by the invariance of the peak in the structure factor
corresponding to nearest-neighbor correlations. At shorter timescales,
picoseconds, two localized relaxation processes of the cation can
be observed, which are not directly linked to ion transport. However,
these processes also show invariance at isoconductivity. This points
to that the overall energy landscape in ionic liquids responds in
the same way to density changes and is mainly governed by the nearest-neighbor
interactions.
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Affiliation(s)
- Filippa Lundin
- Department of Physics, Chalmers University of Technology, SE-41296 Göteborg, Sweden
| | - Henriette Wase Hansen
- Department of Physics, Chalmers University of Technology, SE-41296 Göteborg, Sweden.,Glass and Time, IMFUFA, Department of Science and Environment, Roskilde University, P.O. Box 260, DK-4000 Roskilde, Denmark.,Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, France
| | - Karolina Adrjanowicz
- Insitute of Physics, University of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland
| | - Bernhard Frick
- Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, France
| | - Daniel Rauber
- Department of Chemistry, Saarland University, 66123 Saarbrücken, Germany
| | - Rolf Hempelmann
- Department of Chemistry, Saarland University, 66123 Saarbrücken, Germany
| | | | - Kristine Niss
- Glass and Time, IMFUFA, Department of Science and Environment, Roskilde University, P.O. Box 260, DK-4000 Roskilde, Denmark
| | - Aleksandar Matic
- Department of Physics, Chalmers University of Technology, SE-41296 Göteborg, Sweden
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11
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Shirota H, Ando M, Kakinuma S, Takahashi K. Ultrafast Dynamics in Nonaromatic Cation Based Ionic Liquids: A Femtosecond Raman-Induced Kerr Effect Spectroscopic Study. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2020. [DOI: 10.1246/bcsj.20200198] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Hideaki Shirota
- Department of Chemistry, Chiba University, 1-33 Yayoi, Inage-ku, Chiba 263-8522, Japan
| | - Masatoshi Ando
- Department of Chemistry, Chiba University, 1-33 Yayoi, Inage-ku, Chiba 263-8522, Japan
| | - Shohei Kakinuma
- Department of Chemistry, Chiba University, 1-33 Yayoi, Inage-ku, Chiba 263-8522, Japan
| | - Kotaro Takahashi
- Department of Chemistry, Chiba University, 1-33 Yayoi, Inage-ku, Chiba 263-8522, Japan
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12
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Abstract
The extent to which cations and anions in ionic liquids (ILs) and ionic liquid solutions are dissociated is of both fundamental scientific interest and practical importance because ion dissociation has been shown to impact viscosity, density, surface tension, volatility, solubility, chemical reactivity, and many other important chemical and physical properties. When mixed with solvents, ionic liquids provide the unique opportunity to investigate ion dissociation from infinite dilution in the solvent to a completely solvent-free state, even at ambient conditions. The most common way to estimate ion dissociation in ILs and IL solutions is by comparing the molar conductivity determined from ionic conductivity measurements such as electrochemical impedance spectroscopy (EIS) (which measure the movement of only the charged, i.e., dissociated, ions) with the molar conductivity calculated from ion diffusivities measured by pulse field gradient nuclear magnetic resonance spectroscopy (PFG-NMR, which gives movement of all of the ions). Because the NMR measurements are time-consuming, the number of ILs and IL solutions investigated by this method is relatively limited. We have shown that use of the Stokes-Einstein equation with estimates of the effective ion Stokes radii allows ion dissociation to be calculated from easily measured density, viscosity, and ionic conductivity data (ρ, η, λ), which is readily available in the literature for a much larger number of pure ILs and IL solutions. Therefore, in this review, we present values of ion dissociation for ILs and IL solutions (aqueous and nonaqueous) determined by both the traditional molar conductivity/PFG-NMR method and the ρ, η, λ method. We explore the effect of cation and anion alkyl chain length, structure, and interaction motifs of the cation and anion, temperature, and the strength of the solvent in IL solutions.
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Affiliation(s)
- Oscar Nordness
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
| | - Joan F Brennecke
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
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13
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Wang YL, Li B, Sarman S, Mocci F, Lu ZY, Yuan J, Laaksonen A, Fayer MD. Microstructural and Dynamical Heterogeneities in Ionic Liquids. Chem Rev 2020; 120:5798-5877. [PMID: 32292036 PMCID: PMC7349628 DOI: 10.1021/acs.chemrev.9b00693] [Citation(s) in RCA: 197] [Impact Index Per Article: 49.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Indexed: 12/11/2022]
Abstract
Ionic liquids (ILs) are a special category of molten salts solely composed of ions with varied molecular symmetry and charge delocalization. The versatility in combining varied cation-anion moieties and in functionalizing ions with different atoms and molecular groups contributes to their peculiar interactions ranging from weak isotropic associations to strong, specific, and anisotropic forces. A delicate interplay among intra- and intermolecular interactions facilitates the formation of heterogeneous microstructures and liquid morphologies, which further contributes to their striking dynamical properties. Microstructural and dynamical heterogeneities of ILs lead to their multifaceted properties described by an inherent designer feature, which makes ILs important candidates for novel solvents, electrolytes, and functional materials in academia and industrial applications. Due to a massive number of combinations of ion pairs with ion species having distinct molecular structures and IL mixtures containing varied molecular solvents, a comprehensive understanding of their hierarchical structural and dynamical quantities is of great significance for a rational selection of ILs with appropriate properties and thereafter advancing their macroscopic functionalities in applications. In this review, we comprehensively trace recent advances in understanding delicate interplay of strong and weak interactions that underpin their complex phase behaviors with a particular emphasis on understanding heterogeneous microstructures and dynamics of ILs in bulk liquids, in mixtures with cosolvents, and in interfacial regions.
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Affiliation(s)
- Yong-Lei Wang
- Department
of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Bin Li
- School
of Chemical Engineering and Technology, Sun Yat-sen University, Zhuhai 519082, P. R. China
| | - Sten Sarman
- Department
of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Francesca Mocci
- Department
of Chemical and Geological Sciences, University
of Cagliari, I-09042 Monserrato, Italy
| | - Zhong-Yuan Lu
- State
Key Laboratory of Supramolecular Structure and Materials, Institute
of Theoretical Chemistry, Jilin University, Changchun 130021, P. R. China
| | - Jiayin Yuan
- Department
of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Aatto Laaksonen
- Department
of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
- State
Key Laboratory of Materials-Oriented and Chemical Engineering, Nanjing Tech University, Nanjing 210009, P. R. China
- Centre of
Advanced Research in Bionanoconjugates and Biopolymers, Petru Poni Institute of Macromolecular Chemistry Aleea Grigore Ghica-Voda, 41A, 700487 Iasi, Romania
- Department
of Engineering Sciences and Mathematics, Division of Energy Science, Luleå University of Technology, SE-97187 Luleå, Sweden
| | - Michael D. Fayer
- Department
of Chemistry, Stanford University, Stanford, California 94305, United States
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14
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Khazalpour S, Yarie M, Kianpour E, Amani A, Asadabadi S, Seyf JY, Rezaeivala M, Azizian S, Zolfigol MA. Applications of phosphonium-based ionic liquids in chemical processes. JOURNAL OF THE IRANIAN CHEMICAL SOCIETY 2020. [DOI: 10.1007/s13738-020-01901-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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15
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Harris KR. On the Use of the Angell–Walden Equation To Determine the “Ionicity” of Molten Salts and Ionic Liquids. J Phys Chem B 2019; 123:7014-7023. [DOI: 10.1021/acs.jpcb.9b04443] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kenneth R. Harris
- School of Science, The University of New South Wales, P.O.
Box 7916, Canberra BC ACT 2610, Australia
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16
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Philippi F, Quinten A, Rauber D, Springborg M, Hempelmann R. Density Functional Theory Descriptors for Ionic Liquids and the Introduction of a Coulomb Correction. J Phys Chem A 2019; 123:4188-4200. [DOI: 10.1021/acs.jpca.9b01831] [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)
- Frederik Philippi
- Physical Chemistry, Saarland University, Campus B 2 2, 66123 Saarbrücken, Germany
| | - Anna Quinten
- Physical Chemistry, Saarland University, Campus B 2 2, 66123 Saarbrücken, Germany
| | - Daniel Rauber
- Physical Chemistry, Saarland University, Campus B 2 2, 66123 Saarbrücken, Germany
- Transfercenter Sustainable Electrochemistry, Saarland University and KIST Europe, Am Markt, Zeile 3, 66125 Saarbrücken, Germany
| | - Michael Springborg
- Physical and Theoretical Chemistry, Saarland University, Campus B 2 2, 66123 Saarbrücken, Germany
- School of Materials Science and Engineering, Tianjin University, Tianjin 300072, P. R. China
| | - Rolf Hempelmann
- Physical Chemistry, Saarland University, Campus B 2 2, 66123 Saarbrücken, Germany
- Transfercenter Sustainable Electrochemistry, Saarland University and KIST Europe, Am Markt, Zeile 3, 66125 Saarbrücken, Germany
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17
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Philippi F, Rauber D, Zapp J, Präsang C, Scheschkewitz D, Hempelmann R. Multiple Ether-Functionalized Phosphonium Ionic Liquids as Highly Fluid Electrolytes. Chemphyschem 2019; 20:443-455. [PMID: 30480374 DOI: 10.1002/cphc.201800939] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 11/22/2018] [Indexed: 11/11/2022]
Abstract
Ionic liquids (ILs) are promising electrolytes, although their often high viscosity remains a serious drawback. The latter can be addressed by the introduction of multiple ether functionalization. Based on the highly atom efficient synthesis of tris(2-ethoxyethyl) phosphine, several new phosphonium ionic liquids were prepared, which allows studying the influence of the ether side chains. Their most important physicochemical properties have been determined and will be interpreted using established approaches like ionicity, hole theory, and the Walden plot. There is striking evidence that the properties of phosphonium ionic liquids with the methanesulfonate anion are dominated by aggregation, whereas the two triple ether functionalized ILs with the highest fluidity show almost ideal behavior with other factors being dominant. It is furthermore found that the deviation from ideality is not significantly changed upon introduction of the ether side chains, although a very beneficial impact on the fluidity of ILs is observed. Multiple ether functionalization therefore proves as a powerful tool to overcome the disadvantages of phosphonium ionic liquids with large cations.
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Affiliation(s)
- Frederik Philippi
- Physical Chemistry, Saarland University, Campus B 2 2, 66123, Saarbrücken, Germany
| | - Daniel Rauber
- Physical Chemistry, Saarland University, Campus B 2 2, 66123, Saarbrücken, Germany.,Transfercentre Sustainable Electrochemistry, Saarland University and KIST Europe, Am Markt, Zeile 3, 66125, Saarbrücken, Germany
| | - Josef Zapp
- Pharmaceutical Biology, Saarland University, Campus B 2 3, 66123, Saarbrücken, Germany
| | - Carsten Präsang
- Krupp-Chair of General and Inorganic Chemistry, Saarland University, 66123, Saarbrücken, Germany
| | - David Scheschkewitz
- Krupp-Chair of General and Inorganic Chemistry, Saarland University, 66123, Saarbrücken, Germany
| | - Rolf Hempelmann
- Physical Chemistry, Saarland University, Campus B 2 2, 66123, Saarbrücken, Germany.,Transfercentre Sustainable Electrochemistry, Saarland University and KIST Europe, Am Markt, Zeile 3, 66125, Saarbrücken, Germany
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18
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Philippi F, Rauber D, Springborg M, Hempelmann R. Density Functional Theory Descriptors for Ionic Liquids and the Charge-Transfer Interpretation of the Haven Ratio. J Phys Chem A 2019; 123:851-861. [DOI: 10.1021/acs.jpca.8b10827] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Frederik Philippi
- Physical Chemistry, Saarland University, Campus B 2 2, 66123 Saarbrücken, Germany
| | - Daniel Rauber
- Physical Chemistry, Saarland University, Campus B 2 2, 66123 Saarbrücken, Germany
- Transfercenter Sustainable Electrochemistry, Saarland University and KIST Europe, Am Markt, Zeile 3, 66125 Saarbrücken, Germany
| | - Michael Springborg
- Physical and Theoretical Chemistry, Saarland University, Campus B 2 2, 66123 Saarbrücken, Germany
- School of Materials Science and Engineering, Tianjin University, Tianjin 300072, PR China
| | - Rolf Hempelmann
- Physical Chemistry, Saarland University, Campus B 2 2, 66123 Saarbrücken, Germany
- Transfercenter Sustainable Electrochemistry, Saarland University and KIST Europe, Am Markt, Zeile 3, 66125 Saarbrücken, Germany
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19
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Zheng Q, Thompson SJ, Zhou S, Lail M, Amato K, Rayer AV, Mecham J, Mobley P, Shen J, Fletcher B. Task-Specific Ionic Liquids Functionalized by Cobalt(II) Salen for Room Temperature Biomimetic Dioxygen Binding. Ind Eng Chem Res 2018. [DOI: 10.1021/acs.iecr.8b04224] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Qinghe Zheng
- Technology Advancement & Commercialization Division, RTI International, Durham, North Carolina 27709, United States
| | - Samuel John Thompson
- Technology Advancement & Commercialization Division, RTI International, Durham, North Carolina 27709, United States
| | - Shaojun Zhou
- Technology Advancement & Commercialization Division, RTI International, Durham, North Carolina 27709, United States
| | - Marty Lail
- Technology Advancement & Commercialization Division, RTI International, Durham, North Carolina 27709, United States
| | - Kelly Amato
- Technology Advancement & Commercialization Division, RTI International, Durham, North Carolina 27709, United States
| | - Aravind V. Rayer
- Technology Advancement & Commercialization Division, RTI International, Durham, North Carolina 27709, United States
| | - Jeff Mecham
- Technology Advancement & Commercialization Division, RTI International, Durham, North Carolina 27709, United States
| | - Paul Mobley
- Technology Advancement & Commercialization Division, RTI International, Durham, North Carolina 27709, United States
| | - Jianping Shen
- Technology Advancement & Commercialization Division, RTI International, Durham, North Carolina 27709, United States
| | - Brenda Fletcher
- Technology Advancement & Commercialization Division, RTI International, Durham, North Carolina 27709, United States
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20
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Mondal A, Sunda AP. Molecular dynamics simulations of ammonium/phosphonium-based protic ionic liquids: influence of alkyl to aryl group. Phys Chem Chem Phys 2018; 20:19268-19275. [PMID: 29989116 DOI: 10.1039/c8cp03004a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The variation of the center atom in the cation from an N to a P-atom leads to improved physiochemical properties of protic ionic liquids (PILs) which are suitable for electrolyte applications. We present an atomistic simulations study to compare the effect of an alkyl or aryl group on trioctylammonium triflate ([HN(Oct)3][TFO]) and triphenylammonium triflate ([HN(Ph)3][TFO]) with their phosphonium analogues. We have computed the binding energy from quantum chemical calculations and physical properties such as the viscosity and the electrical conductivity of PILs from molecular dynamics simulations. The influence of the aromatic character in PILs is found to be significant to the physical properties. Gas phase quantum chemical calculations on clusters of ion pairs have revealed the presence of C-H/π interactions in aromatic PILs along with hydrogen bonding. The variation in strength of the ion-pair affinities is examined using electric-current correlation and velocity autocorrelation functions. The qualitative differences observed are due to the aromatic rings and change in the central atom of the quaternary cation from an N to a P-atom, substantiated quantitatively by diffusion coefficients and electrical conductivities. The relatively weaker ion-pair interactions and low binding energy (-73.34 kcal mol-1) lead to the highest electrical conductivity in [HP(Ph)3][TFO].
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Affiliation(s)
- Anirban Mondal
- Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz 55128, Germany.
| | - Anurag Prakash Sunda
- Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, Ajmer 305817, India.
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21
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Rauber D, Philippi F, Zapp J, Kickelbick G, Natter H, Hempelmann R. Transport properties of protic and aprotic guanidinium ionic liquids. RSC Adv 2018; 8:41639-41650. [PMID: 35559272 PMCID: PMC9091945 DOI: 10.1039/c8ra07412g] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 11/16/2018] [Indexed: 12/03/2022] Open
Abstract
Ionic liquids (ILs) are a promising class of solvents, functional fluids and electrolytes that are of high interest for both basic as well as applied research. For further fundamental understanding of ILs and a successful implementation in technical processes, a deeper insight into transport properties and their interrelations is of particular importance. In this contribution we synthesised a series of mostly novel protic and aprotic ILs based on the tetramethylguanidinium (TMG) cation that is a derivative of the superbase guanidine. Different substitution patterns and anions from acids with broadly varied pKa values were investigated. We measured general properties, such as thermal transitions and densities of these ILs, as well as their transport quantities by means of rheology, impedance spectroscopy and NMR diffusometry. Different models for the correlation of the transport properties, namely the Nernst–Einstein, Walden and Stokes–Einstein–Sutherland relations were applied. The deviation from ideal behaviour of fully dissociated electrolytes, often termed as ionicity, was quantified by the reciprocal Haven ratio, fractional Walden rule and ionicity obtained from the Walden plot. Velocity cross-correlation coefficients were calculated to gain further insight into the correlation between ion movements. Both protic and aprotic TMG ILs show transport properties comparable to other ILs with similar molecular weight and high ionicity values especially in contrast to other protic ILs. Lowest ionicity values were found for the protic ILs with smallest ΔpKa values between constituting acid and base. This can either be explained by stronger hydrogen bonding between cation and anion or lower anti-correlations between the oppositely charged ions. These results aim to provide insight into the properties of this interesting cations class and a deeper understanding of the transport properties of ILs and their interrelations in general. New protic and aprotic ionic liquids based on superbase cations show promising properties and enrich the field of cation classes![]()
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Affiliation(s)
- Daniel Rauber
- Physical Chemistry
- Saarland University
- 66123 Saarbrücken
- Germany
- Transfercenter Sustainable Electrochemistry
| | | | - Josef Zapp
- Pharmaceutical Biology
- Saarland University
- 66123 Saarbrücken
- Germany
| | - Guido Kickelbick
- Inorganic Solid State Chemistry
- Saarland University
- 66123 Saarbrücken
- Germany
| | - Harald Natter
- Physical Chemistry
- Saarland University
- 66123 Saarbrücken
- Germany
- Transfercenter Sustainable Electrochemistry
| | - Rolf Hempelmann
- Physical Chemistry
- Saarland University
- 66123 Saarbrücken
- Germany
- Transfercenter Sustainable Electrochemistry
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