1
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McGrogan A, Byrne EL, Guiney R, Headen TF, Youngs TGA, Chrobok A, Holbrey JD, Swadźba-Kwaśny M. The structure of protic ionic liquids based on sulfuric acid, doped with excess of sulfuric acid or with water. Phys Chem Chem Phys 2023; 25:9785-9795. [PMID: 36647728 DOI: 10.1039/d2cp04292d] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Neutron scattering with isotopic substitution was used to study the structure of concentrated sulfuric acid, and two protic ionic liquids (PILs): a Brønsted-acidic PIL, synthesised using pyridine and excess of sulfuric acid, [Hpy][HSO4]·H2SO4, and a hydrated PIL, in which an equimolar mixture of sulfuric acid and pyridine has been doped with water, [Hpy][HSO4]·2H2O. Brønsted acidic PILs are excellent solvents/catalysts for esterifications, driving reaction to completion by phase-separating water and ester products. Water-doped PILs are efficient solvents/antisolvents in biomass fractionation. This study was carried out to provide an insight into the relationship between the performance of PILs in the two respective processes and their liquid structure. It was found that a persistent sulfate/sulfuric acid/water network structure was retained through the transition from sulfuric acid to PILs, even in the presence of 2 moles (∼17 wt%) of water. Hydrogen sulfate PILs have the propensity to incorporate water into hydrogen-bonded anionic chains, with strong and directional hydrogen bonds, which essentially form a new water-in-salt solvent system, with its own distinct structure and physico-chemical properties. It is the properties of this hydrated PIL that can be credited both for the good performance in esterification and beneficial solvent/antisolvent behaviour in biomass fractionation.
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Affiliation(s)
- Anne McGrogan
- The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast, BT9 5AG, UK.
| | - Emily L Byrne
- The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast, BT9 5AG, UK.
| | - Robert Guiney
- The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast, BT9 5AG, UK.
| | - Thomas F Headen
- Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, UK
| | | | - Anna Chrobok
- Department of Chemical Organic Technology and Petrochemistry, Silesian University of Technology, Krzywoustego 4, 44-100, Gilwice, Poland
| | - John D Holbrey
- The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast, BT9 5AG, UK.
| | - Małgorzata Swadźba-Kwaśny
- The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast, BT9 5AG, UK.
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2
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Microstructures of Hydrophobic Ionic Liquids via Tuning Water Networks: Theoretical and Experimental Investigations. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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3
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Terban MW, Billinge SJL. Structural Analysis of Molecular Materials Using the Pair Distribution Function. Chem Rev 2022; 122:1208-1272. [PMID: 34788012 PMCID: PMC8759070 DOI: 10.1021/acs.chemrev.1c00237] [Citation(s) in RCA: 54] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Indexed: 12/16/2022]
Abstract
This is a review of atomic pair distribution function (PDF) analysis as applied to the study of molecular materials. The PDF method is a powerful approach to study short- and intermediate-range order in materials on the nanoscale. It may be obtained from total scattering measurements using X-rays, neutrons, or electrons, and it provides structural details when defects, disorder, or structural ambiguities obscure their elucidation directly in reciprocal space. While its uses in the study of inorganic crystals, glasses, and nanomaterials have been recently highlighted, significant progress has also been made in its application to molecular materials such as carbons, pharmaceuticals, polymers, liquids, coordination compounds, composites, and more. Here, an overview of applications toward a wide variety of molecular compounds (organic and inorganic) and systems with molecular components is presented. We then present pedagogical descriptions and tips for further implementation. Successful utilization of the method requires an interdisciplinary consolidation of material preparation, high quality scattering experimentation, data processing, model formulation, and attentive scrutiny of the results. It is hoped that this article will provide a useful reference to practitioners for PDF applications in a wide realm of molecular sciences, and help new practitioners to get started with this technique.
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Affiliation(s)
- Maxwell W. Terban
- Max
Planck Institute for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Simon J. L. Billinge
- Department
of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, United States
- Condensed
Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, United States
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4
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Shmukler LE, Fedorova IV, Fadeeva Y, Gruzdev MS, Safonova LP. Alkylimidazolium Protic Ionic Liquids: Structural Features and Physicochemical Properties. Chemphyschem 2021; 23:e202100772. [PMID: 34904777 DOI: 10.1002/cphc.202100772] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 12/04/2021] [Indexed: 11/08/2022]
Abstract
We focus on a series of protic ionic liquids (PILs) with imidazolium and alkylimidazolium (1R3HIm, R = methyl, ethyl, propyl, and butyl) cations. Using the literature data and our experimental results on the thermal and transport properties, we analyze the effects of the anion nature and the alkyl radical length in the cation structure on the above properties. DFT calculations in gas and solvent phase have resulted in microscopic insights into the structure and cation-anion binding in these PILs. We show that the higher thermodynamic stability of an ion pair raises the PIL decomposition temperature. The melting points of the salts with the same cation decrease as the hydrocarbon radical in the cation becomes longer, which correlates with the weaker ion-ion interaction in the ion pairs. A comparative analysis of the protic ILs and corresponding ILs (1R3MeIm) with the same radical (R) in the cation structure and the same anion has been performed. The lower melting points of the ILs with 1R3MeIm cations are assumed to result from the weakening both of the ion-ion interaction and hydrogen bond.
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Affiliation(s)
- Liudmila E Shmukler
- G A Krestov Institute of Solution Chemistry Russian Academy of Sciences: Institut himii rastvorov imeni G A Krestova Rossijskoj akademii nauk, laboratory 1-8, RUSSIAN FEDERATION
| | - Irina V Fedorova
- G A Krestov Institute of Solution Chemistry Russian Academy of Sciences: Institut himii rastvorov imeni G A Krestova Rossijskoj akademii nauk, laboratory 1-8, RUSSIAN FEDERATION
| | - Yuliya Fadeeva
- G A Krestov Institute of Solution Chemistry Russian Academy of Sciences: Institut himii rastvorov imeni G A Krestova Rossijskoj akademii nauk, laboratory 1-8, Akademicheskaya, 1, 153045, Ivanovo, RUSSIAN FEDERATION
| | - Matvey S Gruzdev
- G A Krestov Institute of Solution Chemistry Russian Academy of Sciences: Institut himii rastvorov imeni G A Krestova Rossijskoj akademii nauk, laboratory 1-8, RUSSIAN FEDERATION
| | - Liubov P Safonova
- G A Krestov Institute of Solution Chemistry Russian Academy of Sciences: Institut himii rastvorov imeni G A Krestova Rossijskoj akademii nauk, laboratory 1-8, RUSSIAN FEDERATION
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5
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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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6
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Hasani M, Varela LM, Martinelli A. Short-Range Order and Transport Properties in Mixtures of the Protic Ionic Liquid [C 2HIm][TFSI] with Water or Imidazole. J Phys Chem B 2020; 124:1767-1777. [PMID: 31999926 DOI: 10.1021/acs.jpcb.9b10454] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
We investigate the effect of adding different molecular cosolvents, water or imidazole, to the protic ionic liquid 1-ethylimidazolium bis(trifluoromethanesulfonyl)imide, i.e., [C2HIm][TFSI]. We explore how the added cosolvent distributes within the ionic liquid by means of molecular dynamics simulations and X-ray scattering. We also analyze the degree of short-range heterogeneity in the resulting mixtures, finding that while imidazole easily mixes with the protic ionic liquid, water tends to form small clusters in its own water-rich domains. These differences are rationalized by invoking the nature of intermolecular interactions. In aqueous mixtures water-water hydrogen bonds are more likely to form than water-ion hydrogen bonds (water-TFSI bonds being particularly weak), while imidazole can interact with both cations and anions. Hence, the cation-anion association is negligibly influenced by the presence of water, whereas the addition of imidazole creates solvent-separated ion pairs and is thus able to also increase the ionicity. As a consequence of these structural and interactional features, transport properties like self-diffusion and ionic conductivity also show different composition dependencies. While the mobility of both ions and solvent is increased considerably by the addition of water, upon adding imidazole this property changes significantly only for molar fractions of imidazole above 0.6. At these molar fractions, which correspond to a base-excess composition, the imidazole/[C2HIm][TFSI] mixture behaves as a glass-forming liquid with suppressed phase transitions, while homomixtures such as imidazole/[HIm][TFSI] can display a eutectic point.
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Affiliation(s)
- Mohammad Hasani
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Luis Miguel Varela
- Department of Applied and Particle Physics, University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Anna Martinelli
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg, Sweden
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7
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Al-Madhagi LH, Callear SK, Schroeder SLM. Hydrophilic and hydrophobic interactions in concentrated aqueous imidazole solutions: a neutron diffraction and total X-ray scattering study. Phys Chem Chem Phys 2020; 22:5105-5113. [DOI: 10.1039/c9cp05993h] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A study of 5 M aqueous imidazole solutions combining neutron and X-ray diffraction with EPSR simulations shows dominance of hydrogen-bonding between imidazole and water and negligible hydrogen-bonding between imidazole molecules.
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Affiliation(s)
- Laila H. Al-Madhagi
- School of Chemical and Process Engineering
- University of Leeds
- Leeds LS2 9JT
- UK
- Diamond Light Source Ltd
| | | | - Sven L. M. Schroeder
- School of Chemical and Process Engineering
- University of Leeds
- Leeds LS2 9JT
- UK
- Diamond Light Source Ltd
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8
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Rhys NH, Duffy IB, Sowden CL, Lorenz CD, McLain SE. On the hydration of DOPE in solution. J Chem Phys 2019; 150:115104. [PMID: 30902020 DOI: 10.1063/1.5085736] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The atomic-scale hydration structure around the 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) headgroup in a chloroform/water solution has been investigated using neutron diffraction enhanced by isotopic substitution and NMR, coupled with empirical potential structure refinement and molecular dynamics simulations. The results obtained show the preferential binding sites for water molecules on the DOPE headgroups, with the most predominant interactions being with the ammonium and phosphate groups. Interestingly, the level of hydration, as well as the association of DOPE molecules, varies according to the simulation method used. The results here suggest the presence of a tight water network around these lipid headgroups that could affect the permeability of the membrane for lipid-mediated diffusion.
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Affiliation(s)
- Natasha H Rhys
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Imogen B Duffy
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Christopher L Sowden
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Christian D Lorenz
- Department of Physics, King's College London, London WC2R 2LS, United Kingdom
| | - Sylvia E McLain
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
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9
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Turner AH, Kim D. Rotation and translation dynamics of coumarin 153 in choline chloride-based deep eutectic solvents. J Chem Phys 2018; 149:174503. [DOI: 10.1063/1.5038067] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Adam H. Turner
- Department of Physics, Sogang University, Seoul, South Korea
| | - Doseok Kim
- Department of Physics, Sogang University, Seoul, South Korea
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10
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Brown LC, Hogg JM, Gilmore M, Moura L, Imberti S, Gärtner S, Gunaratne HQN, O'Donnell RJ, Artioli N, Holbrey JD, Swadźba-Kwaśny M. Frustrated Lewis pairs in ionic liquids and molecular solvents - a neutron scattering and NMR study of encounter complexes. Chem Commun (Camb) 2018; 54:8689-8692. [PMID: 29938294 DOI: 10.1039/c8cc03794a] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The presence of the weakly-associated encounter complex in the model frustrated Lewis pair solution (FLP): tris(tert-butyl)phosphine (P(tBu)3) and tris(pentafluorophenyl)borane (BCF) in benzene, was confirmed via PB correlation analysis from neutron scattering data. On average, ca. 5% of dissolved FLP components were in the associated state. NMR spectra of the FLP in benzene gave no evidence of such association, in agreement with earlier reports and the transient nature of the encounter complex. In contrast, the corresponding FLP solution in the ionic liquid, 1-decyl-3-methylimidazolium bistriflamide, [C10mim][NTf2], generated NMR signals that can be attributed to formation of encounter complexes involving over 20% of the dissolved species. The low diffusivity characteristics of ionic liquids is suggested to enhance high populations of encounter complex. The FLP in the ionic liquid solution retained its ability to split hydrogen.
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Affiliation(s)
- Lucy C Brown
- The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University of Belfast, Belfast BT9 5AG, UK.
| | - James M Hogg
- The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University of Belfast, Belfast BT9 5AG, UK.
| | - Mark Gilmore
- The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University of Belfast, Belfast BT9 5AG, UK.
| | - Leila Moura
- The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University of Belfast, Belfast BT9 5AG, UK.
| | - Silvia Imberti
- ISIS, Rutherford Appleton Laboratory, Harwell Science & Innovation Campus, Didcot, Oxfordshire OX11 0DE, UK
| | - Sabrina Gärtner
- ISIS, Rutherford Appleton Laboratory, Harwell Science & Innovation Campus, Didcot, Oxfordshire OX11 0DE, UK
| | - H Q Nimal Gunaratne
- The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University of Belfast, Belfast BT9 5AG, UK.
| | - Ruairi J O'Donnell
- The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University of Belfast, Belfast BT9 5AG, UK.
| | - Nancy Artioli
- The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University of Belfast, Belfast BT9 5AG, UK.
| | - John D Holbrey
- The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University of Belfast, Belfast BT9 5AG, UK.
| | - Małgorzata Swadźba-Kwaśny
- The QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University of Belfast, Belfast BT9 5AG, UK.
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