1
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McGrogan A, Lafferty J, O’Neill L, Brown L, Young JM, Goodrich P, Muldoon MJ, Moura L, Youngs S, Hughes TL, Gärtner S, Youngs TGA, Holbrey JD, Swadźba-Kwaśny M. Liquid Structure of Ionic Liquids with [NTf 2] - Anions, Derived from Neutron Scattering. J Phys Chem B 2024; 128:3220-3235. [PMID: 38520396 PMCID: PMC11000221 DOI: 10.1021/acs.jpcb.3c08069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 02/28/2024] [Accepted: 03/12/2024] [Indexed: 03/25/2024]
Abstract
The liquid structure of three common ionic liquids (ILs) was investigated by neutron scattering for the first time. The ILs were based on the bis(trifluoromethanesulfonyl)imide anion, abbreviated in the literature as [NTf2]- or [TFSI]-, and on the following cations: 1-ethyl-3-methylimidazolium, [C2mim]+; 1-decyl-3-methylimidazolium, [C10mim]+; and trihexyl(tetradecyl)phosphonium, [P666,14]+. Comparative analysis of the three ILs confirmed increased size of nonpolar nanodomains with increasing bulk of alkyl chains. It also sheds light on the cation-anion interactions, providing experimental insight into strength, directionality, and angle of hydrogen bonds between protons on the imidazolium ring, as well as H-C-P protons in [P666,14]+, to oxygen and nitrogen atoms in the [NTf2]-. The new Dissolve data analysis package enabled, for the first time, the analysis of neutron scattering data of ILs with long alkyl chains, in particular, of [P666,14][NTf2]. Results generated with Dissolve were validated by comparing outputs from three different models, starting from three different sets of cation charges, for each of the three ILs, which gave convergent outcomes. Finally, a modified method for the synthesis of perdeuterated [P666,14][NTf2] has been reported, with the aim of reporting a complete set of synthetic and data processing approaches, laying robust foundations that enable the study of the phosphonium ILs family by neutron scattering.
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Affiliation(s)
- Anne McGrogan
- QUILL
Research Centre, Queen’s University Belfast, School of Chemistry and Chemical Engineering, David Keir Building, 39-123 Stranmillis Road, Belfast BT9 5AG, Belfast, U.K.
| | - Jack Lafferty
- QUILL
Research Centre, Queen’s University Belfast, School of Chemistry and Chemical Engineering, David Keir Building, 39-123 Stranmillis Road, Belfast BT9 5AG, Belfast, U.K.
| | - Lauren O’Neill
- QUILL
Research Centre, Queen’s University Belfast, School of Chemistry and Chemical Engineering, David Keir Building, 39-123 Stranmillis Road, Belfast BT9 5AG, Belfast, U.K.
| | - Lucy Brown
- QUILL
Research Centre, Queen’s University Belfast, School of Chemistry and Chemical Engineering, David Keir Building, 39-123 Stranmillis Road, Belfast BT9 5AG, Belfast, U.K.
| | - J. Mark. Young
- QUILL
Research Centre, Queen’s University Belfast, School of Chemistry and Chemical Engineering, David Keir Building, 39-123 Stranmillis Road, Belfast BT9 5AG, Belfast, U.K.
| | - Peter Goodrich
- QUILL
Research Centre, Queen’s University Belfast, School of Chemistry and Chemical Engineering, David Keir Building, 39-123 Stranmillis Road, Belfast BT9 5AG, Belfast, U.K.
| | - Mark J. Muldoon
- QUILL
Research Centre, Queen’s University Belfast, School of Chemistry and Chemical Engineering, David Keir Building, 39-123 Stranmillis Road, Belfast BT9 5AG, Belfast, U.K.
| | - Leila Moura
- QUILL
Research Centre, Queen’s University Belfast, School of Chemistry and Chemical Engineering, David Keir Building, 39-123 Stranmillis Road, Belfast BT9 5AG, Belfast, U.K.
| | - Sarah Youngs
- Rutherford
Appleton Laboratory, Chilton, Didcot OX11 0QX, U.K.
| | | | - Sabrina Gärtner
- Rutherford
Appleton Laboratory, Chilton, Didcot OX11 0QX, U.K.
| | | | - John D. Holbrey
- QUILL
Research Centre, Queen’s University Belfast, School of Chemistry and Chemical Engineering, David Keir Building, 39-123 Stranmillis Road, Belfast BT9 5AG, Belfast, U.K.
| | - Małgorzata Swadźba-Kwaśny
- QUILL
Research Centre, Queen’s University Belfast, School of Chemistry and Chemical Engineering, David Keir Building, 39-123 Stranmillis Road, Belfast BT9 5AG, Belfast, U.K.
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2
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Shen Y, Xiao Y, Edkins RM, Youngs TGA, Hughes TL, Tellam J, Edkins K. Elucidating the hydrotropism behaviour of aqueous caffeine and sodium benzoate solution through NMR and neutron total scattering analysis. Int J Pharm 2023; 647:123520. [PMID: 37858637 DOI: 10.1016/j.ijpharm.2023.123520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 10/13/2023] [Accepted: 10/16/2023] [Indexed: 10/21/2023]
Abstract
Hydrotropism is a convenient way to increase the solubility of drugs by up to several orders of magnitude, and even though it has been researched for decades with both experimental and simulation methods, its mechanism is still unknown. Here, we use caffeine/sodium benzoate (CAF-SB) as model system to explore the behaviour of caffeine solubility enhancement in water through NMR spectroscopy and neutron total scattering. 1H NMR shows strong interaction between caffeine and sodium benzoate in water. Neutron total scattering combined with empirical potential structure refinement, a systematic method to study the solution structure, reveals π-stacking between caffeine and the benzoate anion as well as Coulombic interactions with the sodium cation. The strongest hydrogen bond interaction in the system is between benzoate and water, which help dissolve CAF-SB complex and increase the solubility of CAF in water. Besides, the stronger interaction between CAF and water and the distortion of water structure are further mechanisms of the CAF solubility enhancement. It is likely that the variety of mechanisms for hydrotropism shown in this system can be found for other hydrotropes, and NMR spectroscopy and neutron total scattering can be used as complementary techniques to generate a holistic picture of hydrotropic solutions.
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Affiliation(s)
- Yichun Shen
- School of Health Sciences, University of Manchester, Stopford Building, Oxford Road, Manchester M13 9PT, UK
| | - Yitian Xiao
- School of Health Sciences, University of Manchester, Stopford Building, Oxford Road, Manchester M13 9PT, UK
| | - Robert M Edkins
- Department of Pure and Applied Chemistry, University of Strathclyde, Thomas Graham Building, 295, Cathedral Street, Glasgow, G1 1XL, UK
| | - Tristan G A Youngs
- ISIS Pulsed Neutron and Muon Source, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot, OX11 0QX, UK
| | - Terri-Louise Hughes
- ISIS Pulsed Neutron and Muon Source, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot, OX11 0QX, UK
| | - James Tellam
- ISIS Deuteration Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot, OX11 0QX, UK
| | - Katharina Edkins
- School of Health Sciences, University of Manchester, Stopford Building, Oxford Road, Manchester M13 9PT, UK.
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3
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Laurent H, Hughes MDG, Walko M, Brockwell DJ, Mahmoudi N, Youngs TGA, Headen TF, Dougan L. Visualization of Self-Assembly and Hydration of a β-Hairpin through Integrated Small and Wide-Angle Neutron Scattering. Biomacromolecules 2023; 24:4869-4879. [PMID: 37874935 PMCID: PMC10646990 DOI: 10.1021/acs.biomac.3c00583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 10/03/2023] [Indexed: 10/26/2023]
Abstract
Fundamental understanding of the structure and assembly of nanoscale building blocks is crucial for the development of novel biomaterials with defined architectures and function. However, accessing self-consistent structural information across multiple length scales is challenging. This limits opportunities to exploit atomic scale interactions to achieve emergent macroscale properties. In this work we present an integrative small- and wide-angle neutron scattering approach coupled with computational modeling to reveal the multiscale structure of hierarchically self-assembled β hairpins in aqueous solution across 4 orders of magnitude in length scale from 0.1 Å to 300 nm. Our results demonstrate the power of this self-consistent cross-length scale approach and allows us to model both the large-scale self-assembly and small-scale hairpin hydration of the model β hairpin CLN025. Using this combination of techniques, we map the hydrophobic/hydrophilic character of this model self-assembled biomolecular surface with atomic resolution. These results have important implications for the multiscale investigation of aqueous peptides and proteins, for the prediction of ligand binding and molecular associations for drug design, and for understanding the self-assembly of peptides and proteins for functional biomaterials.
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Affiliation(s)
- Harrison Laurent
- School
of Physics and Astronomy, University of
Leeds, Leeds, United Kingdom, LS2
9JT
| | - Matt D. G. Hughes
- School
of Physics and Astronomy, University of
Leeds, Leeds, United Kingdom, LS2
9JT
- Astbury
Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom LS2
9JT
| | - Martin Walko
- School
of Chemistry, University of Leeds, Leeds, United
Kingdom, LS2 9JT
| | - David J. Brockwell
- Astbury
Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom LS2
9JT
| | - Najet Mahmoudi
- ISIS
Neutron and Muon Source, Rutherford Appleton
Laboratory, Harwell Oxford, Didcot, United Kingdom, OX11 0QX
| | - Tristan G. A. Youngs
- ISIS
Neutron and Muon Source, Rutherford Appleton
Laboratory, Harwell Oxford, Didcot, United Kingdom, OX11 0QX
| | - Thomas F. Headen
- ISIS
Neutron and Muon Source, Rutherford Appleton
Laboratory, Harwell Oxford, Didcot, United Kingdom, OX11 0QX
| | - Lorna Dougan
- School
of Physics and Astronomy, University of
Leeds, Leeds, United Kingdom, LS2
9JT
- Astbury
Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom LS2
9JT
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4
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Busch J, Niemann T, Neumann J, Stange P, Gärtner S, Youngs TGA, Youngs S, Paschek D, Ludwig R. The role of hydrogen bond defects for cluster formation and distribution in ionic liquids by means of neutron diffraction and molecular dynamics simulations. Chemphyschem 2023:e202300031. [PMID: 37002728 DOI: 10.1002/cphc.202300031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 03/30/2023] [Accepted: 03/31/2023] [Indexed: 04/03/2023]
Abstract
Defects fundamentally govern the properties of all real materials. Correlating molecular defects to macroscopic quantities remains a challenge, particularly in the liquid phase. Herein, we report the influence of hydrogen bonds (HB) acting as defects in mixtures of non-hydroxyl-functionalized ionic liquids (ILs) with an increasing concentration of hydroxyl-functionalized ILs. We observed two types of HB defects: The conventional HBs between cation and anion (c-a), and the elusive HBs between cations (c-c) despite the repulsive Coulomb forces. We use neutron diffraction with isotopic substitution in combination with molecular dynamics simulations for measuring the geometry, strength, and distribution of mobile OH defects in the IL mixtures. In principle, this procedure allows relating the number and stability of defects to macroscopic properties such as diffusion, viscosity, and conductivity, which are of utmost importance for the performance of electrolytes in batteries and other electrical devices.
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Affiliation(s)
- Johanna Busch
- University of Rostock: Universitat Rostock Chemistry GERMANY
| | - Thomas Niemann
- University of Rostock: Universitat Rostock Chemistry GERMANY
| | - Jan Neumann
- University of Rostock: Universitat Rostock Chemistry GERMANY
| | - Peter Stange
- University of Rostock: Universitat Rostock Chemistry GERMANY
| | - Sabrina Gärtner
- STFC: Science and Technology Facilities Council Isis Facility UNITED KINGDOM
| | | | - Sarah Youngs
- STFC: Science and Technology Facilities Council ISIS Facility UNITED KINGDOM
| | - Dietmar Paschek
- University of Rostock: Universitat Rostock Chemistry GERMANY
| | - Ralf Ludwig
- Universität Rostock Physikalische Chemie Dr.-Lorenz-Weg 1 18051 Rostock GERMANY
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5
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Maity A, Singh S, Mehta S, Youngs TGA, Bahadur J, Polshettiwar V. Insights into the CO 2 Capture Characteristics within the Hierarchical Pores of Carbon Nanospheres Using Small-Angle Neutron Scattering. Langmuir 2023; 39:4382-4393. [PMID: 36920854 DOI: 10.1021/acs.langmuir.2c03474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Understanding adsorption processes at the molecular level has transformed the discovery of engineered materials for maximizing gas storage capacity and kinetics in adsorption-based carbon capture applications. In this work, we studied the molecular mechanism of gas (CO2, H2, methane, and ethane) adsorption inside an interconnected porous network of carbon. This was achieved by synthesizing novel macro-meso-microporous carbon (M3C) nanospheres with interconnected pore structures. The M3Cs showed a CO2 capture capacity of 5.3 mmol/g at atmospheric CO2 pressure, with excellent kinetics. This was due to fast CO2 adsorption within the interconnected hierarchical macro-meso-microporous M3C. In situ small-angle neutron scattering (SANS) under various CO2 pressures indicated that the macro- and mesopores of M3C enable fast diffusion of CO2 molecules inside the micropores, where adsorbed CO2 molecules densify into a liquid-like state. This strong densification of CO2 molecules causes fast CO2 diffusion in the macro- and mesopores of M3C, restarting the adsorption cycle for fresh CO2 molecules until all pores are completely filled. Notably, M3C also showed good capture capacities for hydrogen and various hydrocarbons, with excellent selectivity toward ethane over methane.
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Affiliation(s)
- Ayan Maity
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
| | - Saideep Singh
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
| | - Swati Mehta
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha National Institute, Mumbai 400094, India
| | - Tristan G A Youngs
- ISIS Pulsed Neutron and Muon Source, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX, U.K
| | - Jitendra Bahadur
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha National Institute, Mumbai 400094, India
| | - Vivek Polshettiwar
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
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6
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Busch J, Kotwica D, Al Sheakh L, Headen T, Youngs TGA, Paschek D, Ludwig R. Quantification and Distribution of Three Types of Hydrogen Bonds in Mixtures of an Ionic Liquid with the Hydrogen-Bond-Accepting Molecular Solvent DMSO Explored by Neutron Diffraction and Molecular Dynamics Simulations. J Phys Chem Lett 2023; 14:2684-2691. [PMID: 36892277 DOI: 10.1021/acs.jpclett.3c00018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The concept of hydrogen bonding is celebrating its 100th birthday. Hydrogen bonds (H-bonds) play a key role in the structure and function of biological molecules, the strength of materials, and molecular binding. Herein, we study H-bonding in mixtures of a hydroxyl-functionalized ionic liquid with the neutral, H-bond-accepting molecular liquid dimethylsulfoxide (DMSO) using neutron diffraction experiments and molecular dynamics simulations. We report the geometry, strength, and distribution of three different types of H-bond OH···O, formed between the hydroxyl group of the cation and either the oxygen atom of another cation, the counteranion, or the neutral molecule. Such a variety of different strengths and distributions of H-bonds in one single mixture could hold the promise of providing solvents with potential applications in H-bond-related chemistry, for example, to alter the natural selectivity patterns of catalytic reactions or the conformation of catalysts.
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Affiliation(s)
- Johanna Busch
- Institut für Chemie, Abteilung Physikalische und Theoretische Chemie, Universität Rostock, Albert-Einstein-Str. 27, 18059 Rostock, Germany
| | - David Kotwica
- Institut für Chemie, Abteilung Physikalische und Theoretische Chemie, Universität Rostock, Albert-Einstein-Str. 27, 18059 Rostock, Germany
| | - Loai Al Sheakh
- Institut für Chemie, Abteilung Physikalische und Theoretische Chemie, Universität Rostock, Albert-Einstein-Str. 27, 18059 Rostock, Germany
| | - Thomas Headen
- ISIS Faculty, STFC, Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom
| | - Tristan G A Youngs
- ISIS Faculty, STFC, Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom
| | - Dietmar Paschek
- Institut für Chemie, Abteilung Physikalische und Theoretische Chemie, Universität Rostock, Albert-Einstein-Str. 27, 18059 Rostock, Germany
| | - Ralf Ludwig
- Institut für Chemie, Abteilung Physikalische und Theoretische Chemie, Universität Rostock, Albert-Einstein-Str. 27, 18059 Rostock, Germany
- Department LL&M, Universität Rostock, Albert-Einstein-Str. 25, 18059 Rostock, Germany
- Leibniz-Institut für Katalyse an der Universität Rostock e.V., Albert-Einstein-Str. 29a, 18059 Rostock, Germany
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7
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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: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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8
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Laurent H, Youngs TGA, Headen TF, Soper AK, Dougan L. The ability of trimethylamine N-oxide to resist pressure induced perturbations to water structure. Commun Chem 2022; 5:116. [PMID: 36697784 PMCID: PMC9814673 DOI: 10.1038/s42004-022-00726-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 08/19/2022] [Indexed: 01/28/2023] Open
Abstract
Trimethylamine N-oxide (TMAO) protects organisms from the damaging effects of high pressure. At the molecular level both TMAO and pressure perturb water structure but it is not understood how they act in combination. Here, we use neutron scattering coupled with computational modelling to provide atomistic insight into the structure of water under pressure at 4 kbar in the presence and absence of TMAO. The data reveal that TMAO resists pressure-induced perturbation to water structure, particularly in retaining a clear second solvation shell, enhanced hydrogen bonding between water molecules and strong TMAO - water hydrogen bonds. We calculate an 'osmolyte protection' ratio at which pressure and TMAO-induced energy changes effectively cancel out. Remarkably this ratio translates across scales to the organism level, matching the observed concentration dependence of TMAO in the muscle tissue of organisms as a function of depth. Osmolyte protection may therefore offer a molecular mechanism for the macroscale survival of life in extreme environments.
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Affiliation(s)
- Harrison Laurent
- grid.9909.90000 0004 1936 8403School of Physics and Astronomy, University of Leeds, Leeds, UK
| | - Tristan G. A. Youngs
- grid.76978.370000 0001 2296 6998ISIS Facility, STFC Rutherford Appleton Laboratory, Didcot, UK
| | - Thomas F. Headen
- grid.76978.370000 0001 2296 6998ISIS Facility, STFC Rutherford Appleton Laboratory, Didcot, UK
| | - Alan K. Soper
- grid.76978.370000 0001 2296 6998ISIS Facility, STFC Rutherford Appleton Laboratory, Didcot, UK
| | - Lorna Dougan
- grid.9909.90000 0004 1936 8403School of Physics and Astronomy, University of Leeds, Leeds, UK ,grid.9909.90000 0004 1936 8403Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds, UK
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9
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Moura L, Gilmore M, Callear SK, Youngs TGA, Holbrey JD. Solution structure of propane and propene dissolved in the ionic liquid 1-butyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}imide from neutron diffraction with H/D substitution and empirical potential structure refinement modelling. Mol Phys 2019. [DOI: 10.1080/00268976.2019.1649495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Leila Moura
- QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast, UK
| | - Mark Gilmore
- QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast, UK
| | | | | | - John D. Holbrey
- QUILL Research Centre, School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast, UK
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10
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Niemann T, Neumann J, Stange P, Gärtner S, Youngs TGA, Paschek D, Warr GG, Atkin R, Ludwig R. Die zweigesichtige Natur der Wasserstoffbrückenbindung in hydroxylfunktionalisierten ionischen Flüssigkeiten, offenbart durch Neutronendiffraktometrie und Molekulardynamik‐Simulation. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201904712] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Thomas Niemann
- Universität Rostock Institut für Chemie Abteilung für Physikalische Chemie Dr.-Lorenz-Weg 2 18059 Rostock Deutschland
| | - Jan Neumann
- Universität Rostock Institut für Chemie Abteilung für Physikalische Chemie Albert-Einstein-Str. 21 18059 Rostock Deutschland
| | - Peter Stange
- Universität Rostock Institut für Chemie Abteilung für Physikalische Chemie Dr.-Lorenz-Weg 2 18059 Rostock Deutschland
| | - Sabrina Gärtner
- ISIS Faculty, STFC Rutherford Appleton Laboratory Didcot OX11 0QX UK
| | | | - Dietmar Paschek
- Universität Rostock Institut für Chemie Abteilung für Physikalische Chemie Albert-Einstein-Str. 21 18059 Rostock Deutschland
| | - Gregory G. Warr
- School of Chemistry and Sydney Nano The University of Sydney NSW 2006 Australien
| | - Rob Atkin
- School of Molecular Sciences The University of Western Australia Perth Western Australia 6009 Australien
| | - Ralf Ludwig
- Universität Rostock Institut für Chemie Abteilung für Physikalische Chemie Dr.-Lorenz-Weg 2 18059 Rostock Deutschland
- Department LL&M University of Rostock Albert-Einstein-Str. 25 18059 Rostock Deutschland
- Leibniz-Institut für Katalyse an der Universität Rostock e.V. Albert-Einstein-Str. 29a 18059 Rostock Deutschland
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11
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Niemann T, Neumann J, Stange P, Gärtner S, Youngs TGA, Paschek D, Warr GG, Atkin R, Ludwig R. The Double-Faced Nature of Hydrogen Bonding in Hydroxy-Functionalized Ionic Liquids Shown by Neutron Diffraction and Molecular Dynamics Simulations. Angew Chem Int Ed Engl 2019; 58:12887-12892. [PMID: 31177605 DOI: 10.1002/anie.201904712] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 05/25/2019] [Indexed: 01/14/2023]
Abstract
We characterize the double-faced nature of hydrogen bonding in hydroxy-functionalized ionic liquids by means of neutron diffraction with isotopic substitution (NDIS), molecular dynamics (MD) simulations, and quantum chemical calculations. NDIS data are fit using the empirical potential structure refinement technique (EPSR) to elucidate the nearest neighbor H⋅⋅⋅O and O⋅⋅⋅O pair distribution functions for hydrogen bonds between ions of opposite charge and the same charge. Despite the presence of repulsive Coulomb forces, the cation-cation interaction is stronger than the cation-anion interaction. We compare the hydrogen-bond geometries of both "doubly charged hydrogen bonds" with those reported for molecular liquids, such as water and alcohols. In combination, the NDIS measurements and MD simulations reveal the subtle balance between the two types of hydrogen bonds: The small transition enthalpy suggests that the elusive like-charge attraction is almost competitive with conventional ion-pair formation.
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Affiliation(s)
- Thomas Niemann
- Universität Rostock, Institut für Chemie, Abteilung für Physikalische Chemie, Dr.-Lorenz-Weg 2, 18059, Rostock, Germany
| | - Jan Neumann
- Universität Rostock, Institut für Chemie, Abteilung für Physikalische Chemie, Albert-Einstein-Strasse 21, 18059, Rostock, Germany
| | - Peter Stange
- Universität Rostock, Institut für Chemie, Abteilung für Physikalische Chemie, Dr.-Lorenz-Weg 2, 18059, Rostock, Germany
| | - Sabrina Gärtner
- ISIS Faculty, STFC, Rutherford Appleton Laboratory, Didcot, OX11 0QX, UK
| | - Tristan G A Youngs
- ISIS Faculty, STFC, Rutherford Appleton Laboratory, Didcot, OX11 0QX, UK
| | - Dietmar Paschek
- Universität Rostock, Institut für Chemie, Abteilung für Physikalische Chemie, Albert-Einstein-Strasse 21, 18059, Rostock, Germany
| | - Gregory G Warr
- School of Chemistry and Sydney Nano, The University of Sydney, NSW, 2006, Australia
| | - Rob Atkin
- School of Molecular Sciences, The University of Western Australia, Perth, Western Australia, 6009, Australia
| | - Ralf Ludwig
- Universität Rostock, Institut für Chemie, Abteilung für Physikalische Chemie, Dr.-Lorenz-Weg 2, 18059, Rostock, Germany.,Department LL&M, University of Rostock, Albert-Einstein-Strasse 25, 18059, Rostock, Germany.,Leibniz-Institut für Katalyse an der, Universität Rostock e.V., Albert-Einstein-Strasse 29a, 18059, Rostock, Germany
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12
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Abstract
Liquids under confinement exhibit different properties compared with their corresponding bulk phases, for example, miscibility, phase transitions, and diffusion. The underlying cause is the local ordering of molecules, which is usually only studied using pure simulation methods. Herein, we derive experimentally the structure of benzene confined in MCM-41 using total neutron scattering measurements. The study reveals a layering of molecules across a pore, and four concentric cylindrical shells can be distinguished for a pore with the radius of 18 Å. The nanoscale confinement of the liquid has a major effect on the spatial and orientational correlations observed between the molecules, when compared with the structure of the bulk liquid. These differences are most marked for molecules in parallel configurations, and this suggests differences in chemical reactivity between the confined and bulk liquids.
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Affiliation(s)
- Marta Falkowska
- School of Chemical Engineering and Analytical ScienceThe University of ManchesterUK
| | - Daniel T. Bowron
- ISIS Neutron and Muon SourceScience and Technology Facilities CouncilUK
| | - Haresh Manyar
- School of Chemistry and Chemical EngineeringQueen's University BelfastUK
| | | | - Christopher Hardacre
- School of Chemical Engineering and Analytical ScienceThe University of ManchesterUK
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13
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Affiliation(s)
- Marta Falkowska
- School of Chemical Engineering and Analytical Science The University of Manchester UK
| | - Daniel T. Bowron
- ISIS Neutron and Muon Source Science and Technology Facilities Council UK
| | - Haresh Manyar
- School of Chemistry and Chemical Engineering Queen's University Belfast UK
| | | | - Christopher Hardacre
- School of Chemical Engineering and Analytical Science The University of Manchester UK
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14
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Cox SJ, Taylor DJF, Youngs TGA, Soper AK, Totton TS, Chapman RG, Arjmandi M, Hodges MG, Skipper NT, Michaelides A. Formation of Methane Hydrate in the Presence of Natural and Synthetic Nanoparticles. J Am Chem Soc 2018; 140:3277-3284. [PMID: 29401390 PMCID: PMC5860788 DOI: 10.1021/jacs.7b12050] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
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Natural gas hydrates occur widely
on the ocean-bed and in permafrost
regions, and have potential as an untapped energy resource. Their
formation and growth, however, poses major problems for the energy
sector due to their tendency to block oil and gas pipelines, whereas
their melting is viewed as a potential contributor to climate change.
Although recent advances have been made in understanding bulk methane
hydrate formation, the effect of impurity particles, which are always
present under conditions relevant to industry and the environment,
remains an open question. Here we present results from neutron scattering
experiments and molecular dynamics simulations that show that the
formation of methane hydrate is insensitive to the addition of a wide
range of impurity particles. Our analysis shows that this is due to
the different chemical natures of methane and water, with methane
generally excluded from the volume surrounding the nanoparticles.
This has important consequences for our understanding of the mechanism
of hydrate nucleation and the design of new inhibitor molecules.
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Affiliation(s)
- Stephen J Cox
- Department of Chemistry , University College London , 20 Gordon Street , London WC1H 0AJ , United Kingdom.,Thomas Young Centre and London Centre for Nanotechnology , 17-19 Gordon Street , London WC1H 0AH , United Kingdom
| | - Diana J F Taylor
- Thomas Young Centre and London Centre for Nanotechnology , 17-19 Gordon Street , London WC1H 0AH , United Kingdom.,Department of Physics and Astronomy , University College London , Gower Street , London WC1E 6BT , United Kingdom
| | - Tristan G A Youngs
- ISIS Facility , STFC Rutherford Appleton Laboratory , Harwell Oxford , Didcot OX11 0QX , United Kingdom
| | - Alan K Soper
- ISIS Facility , STFC Rutherford Appleton Laboratory , Harwell Oxford , Didcot OX11 0QX , United Kingdom
| | - Tim S Totton
- BP Exploration Operating Co. Ltd , Chertsey Road , Sunbury-on-Thames TW16 7LN , United Kingdom
| | - Richard G Chapman
- BP Exploration Operating Co. Ltd , Chertsey Road , Sunbury-on-Thames TW16 7LN , United Kingdom
| | - Mosayyeb Arjmandi
- BP Exploration Operating Co. Ltd , Chertsey Road , Sunbury-on-Thames TW16 7LN , United Kingdom
| | - Michael G Hodges
- BP Exploration Operating Co. Ltd , Chertsey Road , Sunbury-on-Thames TW16 7LN , United Kingdom
| | - Neal T Skipper
- Thomas Young Centre and London Centre for Nanotechnology , 17-19 Gordon Street , London WC1H 0AH , United Kingdom.,Department of Physics and Astronomy , University College London , Gower Street , London WC1E 6BT , United Kingdom
| | - Angelos Michaelides
- Thomas Young Centre and London Centre for Nanotechnology , 17-19 Gordon Street , London WC1H 0AH , United Kingdom.,Department of Physics and Astronomy , University College London , Gower Street , London WC1E 6BT , United Kingdom
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15
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Leutzsch M, Falkowska M, Hughes TL, Sederman AJ, Gladden LF, Mantle MD, Youngs TGA, Bowron D, Manyar H, Hardacre C. An integrated total neutron scattering – NMR approach for the study of heterogeneous catalysis. Chem Commun (Camb) 2018; 54:10191-10194. [DOI: 10.1039/c8cc04740e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
By combining total neutron scattering with nuclear magnetic resonance (NeuNMR) in a single experimental apparatus, new insights into the kinetics and mechanisms of heterogeneous catalytic reactions occurring in situ, within the catalyst pore space, are possible.
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Affiliation(s)
- Markus Leutzsch
- Department of Chemical Engineering and Biotechnology
- Philippa Fawcett Drive
- University of Cambridge
- Cambridge
- UK
| | - Marta Falkowska
- School of Chemical Engineering and Analytical Science
- The University of Manchester
- Manchester
- UK
| | - Terri-Louise Hughes
- School of Chemical Engineering and Analytical Science
- The University of Manchester
- Manchester
- UK
| | - Andrew J. Sederman
- Department of Chemical Engineering and Biotechnology
- Philippa Fawcett Drive
- University of Cambridge
- Cambridge
- UK
| | - Lynn F. Gladden
- Department of Chemical Engineering and Biotechnology
- Philippa Fawcett Drive
- University of Cambridge
- Cambridge
- UK
| | - Michael D. Mantle
- Department of Chemical Engineering and Biotechnology
- Philippa Fawcett Drive
- University of Cambridge
- Cambridge
- UK
| | | | - Daniel Bowron
- STFC ISIS Facility
- Rutherford Appleton Laboratory Chilton
- Didcot
- UK
| | - Haresh Manyar
- School of Chemistry and Chemical Engineering
- Queen's University Belfast
- UK
| | - Christopher Hardacre
- School of Chemical Engineering and Analytical Science
- The University of Manchester
- Manchester
- UK
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16
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Szala-Bilnik J, Falkowska M, Bowron DT, Hardacre C, Youngs TGA. The Structure of Ethylbenzene, Styrene and Phenylacetylene Determined by Total Neutron Scattering. Chemphyschem 2017; 18:2541-2548. [PMID: 28672104 PMCID: PMC5811833 DOI: 10.1002/cphc.201700393] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 06/30/2017] [Indexed: 11/10/2022]
Abstract
Organic solvents such as phenylacetylene, styrene and ethylbenzene are widely used in industrial processes, especially in the production of rubber or thermoplastics. Despite their important applications detailed knowledge about their structure is limited. In this paper the structures of these three aromatic solvents were investigated using neutron diffraction. The results show that many of their structural characteristics are similar, although the structure of phenylacetylene is more ordered and has a smaller solvation sphere than either ethylbenzene or styrene. Two regions within the first coordination sphere, in which the surrounding molecules show different preferable orientations with respect to the central molecule, were found for each liquid. Additionally, the localisation of the aliphatic chains reveals that they tend to favour closer interactions with each other than to the aromatic rings of the adjacent molecules.
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Affiliation(s)
- Joanna Szala-Bilnik
- School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester, M13 9PL, UK.,STFC ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX, UK
| | - Marta Falkowska
- STFC ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX, UK.,School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast, BT9 5AG, UK
| | - Daniel T Bowron
- STFC ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX, UK
| | - Christopher Hardacre
- School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester, M13 9PL, UK
| | - Tristan G A Youngs
- STFC ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX, UK
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17
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Stefanopoulos KL, Youngs TGA, Sakurovs R, Ruppert LF, Bahadur J, Melnichenko YB. Neutron Scattering Measurements of Carbon Dioxide Adsorption in Pores within the Marcellus Shale: Implications for Sequestration. Environ Sci Technol 2017; 51:6515-6521. [PMID: 28463504 DOI: 10.1021/acs.est.6b05707] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Shale is an increasingly viable source of natural gas and a potential candidate for geologic CO2 sequestration. Understanding the gas adsorption behavior on shale is necessary for the design of optimal gas recovery and sequestration projects. In the present study neutron diffraction and small-angle neutron scattering measurements of adsorbed CO2 in Marcellus Shale samples were conducted on the Near and InterMediate Range Order Diffractometer (NIMROD) at the ISIS Pulsed Neutron and Muon Source, STFC Rutherford Appleton Laboratory along an adsorption isotherm of 22 °C and pressures of 25 and 40 bar. Additional measurements were conducted at approximately 22 and 60 °C at the same pressures on the General-Purpose Small-Angle Neutron Scattering (GP-SANS) instrument at Oak Ridge National Laboratory. The structures investigated (pores) for CO2 adsorption range in size from Å level to ∼50 nm. The results indicate that, using the conditions investigated densification or condensation effects occurred in all accessible pores. The data suggest that at 22 °C the CO2 has liquid-like properties when confined in pores of around 1 nm radius at pressures as low as 25 bar. Many of the 2.5 nm pores, 70% of 2 nm pores, most of the <1 nm pores, and all pores <0.25 nm, are inaccessible or closed to CO2, suggesting that despite the vast numbers of micropores in shale, the micropores will be unavailable for storage for geologic CO2 sequestration.
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Affiliation(s)
| | - Tristan G A Youngs
- Disordered Materials Group (ISIS), STFC Rutherford Appleton Laboratory , Oxfordshire, U.K
| | - Richard Sakurovs
- CSIRO Energy, CSIRO Riverside Life Sciences Centre , Sydney, Australia
| | - Leslie F Ruppert
- U.S. Geological Survey, Eastern Energy Resource Science Center , Reston, Virginia 20192, United States
| | - Jitendra Bahadur
- Biology and Soft Matter Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee, 37830, United States
| | - Yuri B Melnichenko
- Biology and Soft Matter Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee, 37830, United States
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18
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Abstract
The local solvation environment of uracil dissolved in the ionic liquid 1-ethyl-3-methylimidazolium acetate has been studied using neutron diffraction techniques. At solvent:solute (ionic liquid:uracil) ratios of 3:1 and 2:1, little perturbation of the ion-ion correlations compared to those of the neat ionic liquid are observed. We find that solvation of the uracil is driven predominantly by the acetate anion of the solvent. While short distance correlations exist between uracil and the imidazolium cation, the geometry of these contacts suggest that they cannot be considered as hydrogen bonds, in contrast to other studies by Araújo et al. (J. M. Araújo, A. B. Pereiro, J. N. Canongia-Lopes, L. P. Rebelo, I. M. Marrucho, J. Phys. Chem. B 2013, 117, 4109-4120). Nevertheless, this combination of interactions of the solute with both the cation and anion components of the solvents helps explain the high solubility of the nucleobase in this media. In addition, favourable uracil-uracil contacts are observed, of similar magnitude to those between cation and uracil, and are also likely to aid dissolution.
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Affiliation(s)
- Sarah E Norman
- ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire, OX11 0QX, UK.,School of Chemistry and Chemical Engineering, David Keir Building, Queen's University Belfast, Belfast, Northern Ireland, BT9 5AG, UK
| | - Adam H Turner
- School of Chemistry and Chemical Engineering, David Keir Building, Queen's University Belfast, Belfast, Northern Ireland, BT9 5AG, UK
| | - John D Holbrey
- School of Chemistry and Chemical Engineering, David Keir Building, Queen's University Belfast, Belfast, Northern Ireland, BT9 5AG, UK
| | - Tristan G A Youngs
- ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire, OX11 0QX, UK
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19
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Youngs TGA, Falkowska M, Bowron DT, Hardacre C. Confined liquid structure and chemical kinetics from total neutron scattering. Acta Crystallogr A Found Adv 2016. [DOI: 10.1107/s2053273316097655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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20
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Abstract
Organic solvents, such as cyclohexane, cyclohexene, methylcyclohexane, benzene and toluene, are widely used as both reagents and solvents in industrial processes. Despite the ubiquity of these liquids, the local structures that govern the chemical properties have not been studied extensively. Herein, we report neutron diffraction measurements on liquid cyclohexane, cyclohexene, methylcyclohexane, benzene and toluene at 298 K to obtain a detailed description of the local structure in these compounds. The radial distribution functions of the centres of the molecules, as well as the partial distribution functions for the double bond for cyclohexene and methyl group for methylcyclohexane and toluene have been calculated. Additionally, probability density functions and angular radial distribution functions were extracted to provide a full description of the local structure within the chosen liquids. Structural motifs are discussed and compared for all liquids, referring specifically to the functional group and aromaticity present in the different liquids.
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Affiliation(s)
- Marta Falkowska
- STFC ISIS Facility, Rutherford Appleton Laboratory, Harwell, Oxford, Didcot, Oxon, OX11 0QX, UK.,CenTACat, School of Chemistry and Chemical Engineering, Queen's University, Belfast, Stranmillis Road, BT9 5AG, UK
| | - Daniel T Bowron
- STFC ISIS Facility, Rutherford Appleton Laboratory, Harwell, Oxford, Didcot, Oxon, OX11 0QX, UK
| | - Haresh G Manyar
- CenTACat, School of Chemistry and Chemical Engineering, Queen's University, Belfast, Stranmillis Road, BT9 5AG, UK
| | - Christopher Hardacre
- CenTACat, School of Chemistry and Chemical Engineering, Queen's University, Belfast, Stranmillis Road, BT9 5AG, UK.
| | - Tristan G A Youngs
- STFC ISIS Facility, Rutherford Appleton Laboratory, Harwell, Oxford, Didcot, Oxon, OX11 0QX, UK.
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21
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Schumacher M, Weber H, Jóvári P, Tsuchiya Y, Youngs TGA, Kaban I, Mazzarello R. Structural, electronic and kinetic properties of the phase-change material Ge2Sb2Te5 in the liquid state. Sci Rep 2016; 6:27434. [PMID: 27272222 PMCID: PMC4897623 DOI: 10.1038/srep27434] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 05/18/2016] [Indexed: 11/09/2022] Open
Abstract
Phase-change materials exhibit fast and reversible transitions between an amorphous and a crystalline state at high temperature. The two states display resistivity contrast, which is exploited in phase-change memory devices. The technologically most important family of phase-change materials consists of Ge-Sb-Te alloys. In this work, we investigate the structural, electronic and kinetic properties of liquid Ge2Sb2Te5 as a function of temperature by a combined experimental and computational approach. Understanding the properties of this phase is important to clarify the amorphization and crystallization processes. We show that the structural properties of the models obtained from ab initio and reverse Monte Carlo simulations are in good agreement with neutron and X-ray diffraction experiments. We extract the kinetic coefficients from the molecular dynamics trajectories and determine the activation energy for viscosity. The obtained value is shown to be fully compatible with our viscosity measurements.
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Affiliation(s)
- Mathias Schumacher
- Institute for Theoretical Solid State Physics, RWTH Aachen University, 52056 Aachen, Germany
| | - Hans Weber
- IFW Dresden, Institute for Complex Materials, PO Box 270116, 01171 Dresden, Germany.,TU Dresden, Institut für Strukturphysik, 01062 Dresden, Germany
| | - Pál Jóvári
- Wigner Research Centre for Physics, Institute for Solid State Physics and Optics, PO Box 49, 1525 Budapest, Hungary
| | - Yoshimi Tsuchiya
- Department of Physics, Faculty of Science, Niigata University, Ikarashi 2-8050, Niigata 950-21, Japan
| | - Tristan G A Youngs
- ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot, UK
| | - Ivan Kaban
- IFW Dresden, Institute for Complex Materials, PO Box 270116, 01171 Dresden, Germany
| | - Riccardo Mazzarello
- Institute for Theoretical Solid State Physics, RWTH Aachen University, 52056 Aachen, Germany.,JARA-FIT and JARA-HPC, RWTH Aachen University, 52056 Aachen, Germany
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22
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Hill CR, Mitterdorfer C, Youngs TGA, Bowron DT, Fraser HJ, Loerting T. Neutron Scattering Analysis of Water's Glass Transition and Micropore Collapse in Amorphous Solid Water. Phys Rev Lett 2016; 116:215501. [PMID: 27284664 DOI: 10.1103/physrevlett.116.215501] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Indexed: 06/06/2023]
Abstract
The question of the nature of water's glass transition has continued to be disputed over many years. Here we use slow heating scans (0.4 K min^{-1}) of compact amorphous solid water deposited at 77 K and an analysis of the accompanying changes in the small-angle neutron scattering signal, to study mesoscale changes in the ice network topology. From the data we infer the onset of rotational diffusion at 115 K, a sudden switchover from nondiffusive motion and enthalpy relaxation of the network at <121 K to diffusive motion across sample grains and sudden pore collapse at >121 K, in excellent agreement with the glass transition onset deduced from heat capacity and dielectric measurements. This indicates that water's glass transition is linked with long-range transport of water molecules on the time scale of minutes and, thus, clarifies its nature. Furthermore, the slow heating rates combined with the high crystallization resistance of the amorphous sample allow us to identify the glass transition end point at 136 K, which is well separated from the crystallization onset at 144 K-in contrast to all earlier experiments in the field.
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Affiliation(s)
- Catherine R Hill
- Department of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA, United Kingdom
| | | | - Tristan G A Youngs
- ISIS Facility, Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxon OX11 0QX, United Kingdom
| | - Daniel T Bowron
- ISIS Facility, Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxon OX11 0QX, United Kingdom
| | - Helen J Fraser
- Department of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA, United Kingdom
| | - Thomas Loerting
- Institute of Physical Chemistry, University of Innsbruck, A-6020 Innsbruck, Austria
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23
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Stefanopoulos KL, Katsaros FK, Steriotis TA, Sapalidis AA, Thommes M, Bowron DT, Youngs TGA. Anomalous Depletion of Pore-Confined Carbon Dioxide upon Cooling below the Bulk Triple Point: An In Situ Neutron Diffraction Study. Phys Rev Lett 2016; 116:025502. [PMID: 26824548 DOI: 10.1103/physrevlett.116.025502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Indexed: 06/05/2023]
Abstract
The phase behavior of sorbed CO{2} in an ordered mesoporous silica sample (SBA-15) was studied by neutron diffraction. Surprisingly, upon cooling our sample below the bulk critical point, confined CO{2} molecules neither freeze nor remain liquid as expected, but escape from the pores. The phenomenon has additionally been confirmed gravimetrically. The process is reversible and during heating CO{2} refills the pores, albeit with hysteresis. This depletion was for the first time observed in an ordered mesoporous molecular sieve and provides new insight on the phase behavior of nanoconfined fluids.
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Affiliation(s)
- K L Stefanopoulos
- Institute of Nanoscience and Nanotechnology, NCSR "Demokritos", 15310 Ag. Paraskevi Attikis, Athens, Greece
| | - F K Katsaros
- Institute of Nanoscience and Nanotechnology, NCSR "Demokritos", 15310 Ag. Paraskevi Attikis, Athens, Greece
| | - Th A Steriotis
- Institute of Nanoscience and Nanotechnology, NCSR "Demokritos", 15310 Ag. Paraskevi Attikis, Athens, Greece
| | - A A Sapalidis
- Institute of Nanoscience and Nanotechnology, NCSR "Demokritos", 15310 Ag. Paraskevi Attikis, Athens, Greece
| | - M Thommes
- Quantachrome Instruments, 1900 Corporate Drive, Boynton Beach, Florida, USA
| | - D T Bowron
- ISIS Neutron and Muon Source, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX, United Kingdom
| | - T G A Youngs
- ISIS Neutron and Muon Source, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX, United Kingdom
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24
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Falkowska M, Chansai S, Manyar HG, Gladden LF, Bowron DT, Youngs TGA, Hardacre C. Determination of toluene hydrogenation kinetics with neutron diffraction. Phys Chem Chem Phys 2016; 18:17237-43. [DOI: 10.1039/c6cp01494a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Total neutron scattering has been used to follow the hydrogenation of toluene-d8 to methylcyclohexane-d14 over 3 wt% platinum supported on highly ordered mesoporous silica (MCM-41) at 298 K and under 150–250 mbar D2 pressure.
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Affiliation(s)
- Marta Falkowska
- STFC ISIS Facility
- Rutherford Appleton Laboratory
- Harwell Campus
- Oxon
- UK
| | - Sarayute Chansai
- CenTACat
- School of Chemistry and Chemical Engineering
- Queen's University Belfast
- UK
| | - Haresh G. Manyar
- CenTACat
- School of Chemistry and Chemical Engineering
- Queen's University Belfast
- UK
| | - Lynn F. Gladden
- Department of Chemical Engineering and Biotechnology
- University of Cambridge
- Cambridge CB2 3RA
- UK
| | - Daniel T. Bowron
- STFC ISIS Facility
- Rutherford Appleton Laboratory
- Harwell Campus
- Oxon
- UK
| | | | - Christopher Hardacre
- CenTACat
- School of Chemistry and Chemical Engineering
- Queen's University Belfast
- UK
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25
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Cunningham R, Forero-Martinez NC, Hardacre C, Youngs TGA, Migaud ME. Solubility study of tobramycin in room temperature ionic liquids: an experimental and computational based study. RSC Adv 2016. [DOI: 10.1039/c6ra23078d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Herein, we present a computational and experimental study assessing the solubility of tobramycin1in a series of hydrophilic room temperature ionic liquids (RTIL).
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Affiliation(s)
| | | | - Christopher Hardacre
- School of Chemistry and Chemical Engineering
- Queen's University Belfast
- Belfast BT9 5AG
- UK
- School of Chemical Engineering & Analytical Science
| | | | - Marie E. Migaud
- School of Pharmacy
- Queen's University Belfast
- Belfast BT9 7BL
- UK
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26
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Humphreys EK, Allan PK, Welbourn RJL, Youngs TGA, Soper AK, Grey CP, Clarke SM. A Neutron Diffraction Study of the Electrochemical Double Layer Capacitor Electrolyte Tetrapropylammonium Bromide in Acetonitrile. J Phys Chem B 2015; 119:15320-33. [DOI: 10.1021/acs.jpcb.5b08248] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Elizabeth K. Humphreys
- Department
of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Phoebe K. Allan
- Department
of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
- Gonville and Caius College, Trinity
Street, Cambridge CB2 1TA, United Kingdom
| | - Rebecca J. L. Welbourn
- Department
of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
- BP Institute, University of Cambridge, Madingley Road, Cambridge CB3 0EZ, United Kingdom
| | - Tristan G. A. Youngs
- ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot, OX11 0QX, United Kingdom
| | - Alan K. Soper
- ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot, OX11 0QX, United Kingdom
| | - Clare P. Grey
- Department
of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Stuart M. Clarke
- Department
of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
- BP Institute, University of Cambridge, Madingley Road, Cambridge CB3 0EZ, United Kingdom
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27
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McCune JA, Turner AH, Coleman F, White CM, Callear SK, Youngs TGA, Swadźba-Kwaśny M, Holbrey JD. Association and liquid structure of pyridine–acetic acid mixtures determined from neutron scattering using a ‘free proton’ EPSR simulation model. Phys Chem Chem Phys 2015; 17:6767-77. [DOI: 10.1039/c4cp05746e] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Hydrogen-bonded molecular acetic acid chains are observed in acid–base mixtures from small angle neutron diffraction.
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Affiliation(s)
- Jade A. McCune
- The QUILL Research Centre
- School of Chemistry and Chemical Engineering, Queen's University Belfast
- Belfast BT9 5AG
- UK
| | - Adam H. Turner
- The QUILL Research Centre
- School of Chemistry and Chemical Engineering, Queen's University Belfast
- Belfast BT9 5AG
- UK
| | - Fergal Coleman
- The QUILL Research Centre
- School of Chemistry and Chemical Engineering, Queen's University Belfast
- Belfast BT9 5AG
- UK
| | - Caithlin M. White
- 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
| | - John D. Holbrey
- The QUILL Research Centre
- School of Chemistry and Chemical Engineering, Queen's University Belfast
- Belfast BT9 5AG
- UK
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28
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McGregor J, Li R, Zeitler JA, D'Agostino C, Collins JHP, Mantle MD, Manyar H, Holbrey JD, Falkowska M, Youngs TGA, Hardacre C, Stitt EH, Gladden LF. Structure and dynamics of aqueous 2-propanol: a THz-TDS, NMR and neutron diffraction study. Phys Chem Chem Phys 2015; 17:30481-91. [DOI: 10.1039/c5cp01132a] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
90 molH2O% is identified as a critical composition at which alcohol–water interactions are maximised; with 4–5 H2O molecules present in the hydration shell per 2-propanol.
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Affiliation(s)
- James McGregor
- Department of Chemical Engineering and Biotechnology
- University of Cambridge
- Cambridge CB2 3RA
- UK
| | - Ruoyu Li
- Department of Chemical Engineering and Biotechnology
- University of Cambridge
- Cambridge CB2 3RA
- UK
| | - J. Axel Zeitler
- Department of Chemical Engineering and Biotechnology
- University of Cambridge
- Cambridge CB2 3RA
- UK
| | - Carmine D'Agostino
- Department of Chemical Engineering and Biotechnology
- University of Cambridge
- Cambridge CB2 3RA
- UK
| | - James H. P. Collins
- Department of Chemical Engineering and Biotechnology
- University of Cambridge
- Cambridge CB2 3RA
- UK
| | - Mick D. Mantle
- Department of Chemical Engineering and Biotechnology
- University of Cambridge
- Cambridge CB2 3RA
- UK
| | - Haresh Manyar
- School of Chemistry and Chemical Engineering
- Queen's University Belfast
- Belfast BT9 5AG
- UK
| | - John D. Holbrey
- School of Chemistry and Chemical Engineering
- Queen's University Belfast
- Belfast BT9 5AG
- UK
| | - Marta Falkowska
- School of Chemistry and Chemical Engineering
- Queen's University Belfast
- Belfast BT9 5AG
- UK
| | | | - Christopher Hardacre
- School of Chemistry and Chemical Engineering
- Queen's University Belfast
- Belfast BT9 5AG
- UK
| | | | - Lynn F. Gladden
- Department of Chemical Engineering and Biotechnology
- University of Cambridge
- Cambridge CB2 3RA
- UK
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29
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Mitterdorfer C, Bauer M, Youngs TGA, Bowron DT, Hill CR, Fraser HJ, Finney JL, Loerting T. Small-angle neutron scattering study of micropore collapse in amorphous solid water. Phys Chem Chem Phys 2014; 16:16013-20. [DOI: 10.1039/c4cp00593g] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Amorphous solid water (ASW) is shown to undergo a micropore collapse from cylindrical pores (3D) to lamellae (2D) at >120 K using small-angle neutron scattering.
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Affiliation(s)
| | - Marion Bauer
- Institute of General
- Inorganic and Theoretical Chemistry
- University of Innsbruck
- A-6020 Innsbruck, Austria
| | | | - Daniel T. Bowron
- ISIS Facility
- Rutherford Appleton Laboratory
- Harwell Oxford
- Didcot, UK
| | - Catherine R. Hill
- Department of Physical Sciences
- The Open University
- Milton Keynes MK7 6AA, UK
| | - Helen J. Fraser
- Department of Physical Sciences
- The Open University
- Milton Keynes MK7 6AA, UK
| | - John L. Finney
- Department of Physics and Astronomy and London Centre for Nanotechnology
- University College London
- London WC1E 6BT, UK
| | - Thomas Loerting
- Institute of Physical Chemistry
- University of Innsbruck
- A-6020 Innsbruck, Austria
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30
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Youngs TGA, Manyar H, Bowron DT, Gladden LF, Hardacre C. Probing chemistry and kinetics of reactions in heterogeneous catalysts. Chem Sci 2013. [DOI: 10.1039/c3sc51477c] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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31
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Jacquemin J, Bendová M, Sedláková Z, Blesic M, Holbrey JD, Mullan CL, Youngs TGA, Pison L, Wagner Z, Aim K, Gomes MFC, Hardacre C. Phase Behaviour, Interactions, and Structural Studies of (Amines+Ionic Liquids) Binary Mixtures. Chemphyschem 2012; 13:1825-35. [DOI: 10.1002/cphc.201100952] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 01/26/2012] [Indexed: 11/08/2022]
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32
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Kohanoff J, Pinilla C, Youngs TGA, Artacho E, Soler JM. Dispersion interactions in room-temperature ionic liquids: results from a non-empirical density functional. J Chem Phys 2012; 135:154505. [PMID: 22029322 DOI: 10.1063/1.3652897] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The role of dispersion or van de Waals (VDW) interactions in imidazolium-based room-temperature ionic liquids is studied within the framework of density functional theory, using a recently developed non-empirical functional [M. Dion, H. Rydberg, E. Schröder, D. C. Langreth, and B. I. Lundqvist, Phys. Rev. Lett. 92, 246401 (2004)], as efficiently implemented in the SIESTA code [G. Román-Pérez and J. M. Soler, Phys. Rev. Lett. 103, 096102 (2009)]. We present results for the equilibrium structure and lattice parameters of several crystalline phases, finding a general improvement with respect to both the local density (LDA) and the generalized gradient approximations (GGA). Similar to other systems characterized by VDW bonding, such as rare gas and benzene dimers as well as solid argon, equilibrium distances and volumes are consistently overestimated by ≈7%, compared to -11% within LDA and 11% within GGA. The intramolecular geometries are retained, while the intermolecular distances and orientations are significantly improved relative to LDA and GGA. The quality is superior to that achieved with tailor-made empirical VDW corrections ad hoc [M. G. Del Pópolo, C. Pinilla, and P. Ballone, J. Chem. Phys. 126, 144705 (2007)]. We also analyse the performance of an optimized version of this non-empirical functional, where the screening properties of the exchange have been tuned to reproduce high-level quantum chemical calculations [J. Klimes, D. Bowler, and A. Michaelides, J. Phys.: Condens. Matter 22, 074203 (2010)]. The results for solids are even better with volumes and geometries reproduced within 2% of experimental data. We provide some insight into the issue of polymorphism of [bmim][Cl] crystals, and we present results for the geometry and energetics of [bmim][Tf] and [mmim][Cl] neutral and charged clusters, which validate the use of empirical force fields.
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Affiliation(s)
- Jorge Kohanoff
- Atomistic Simulation Centre, Queen's University Belfast, Belfast BT7 1NN, Northern IrelandSchool of Chemistry, University of Bristol, Bristol BS2 1TS, United Kingdom.
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33
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Youngs TGA, Holbrey JD, Mullan CL, Norman SE, Lagunas MC, D'Agostino C, Mantle MD, Gladden LF, Bowron DT, Hardacre C. Neutron diffraction, NMR and molecular dynamics study of glucose dissolved in the ionic liquid 1-ethyl-3-methylimidazolium acetate. Chem Sci 2011. [DOI: 10.1039/c1sc00241d] [Citation(s) in RCA: 110] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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34
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Youngs TGA, Hardacre C. Effect of hydrophobic nanopatches within an ionic surface on the structure of liquids. Phys Chem Chem Phys 2011; 13:582-5. [DOI: 10.1039/c0cp01838d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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35
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Hardacre C, Holbrey JD, Mullan CL, Youngs TGA, Bowron DT. Small angle neutron scattering from 1-alkyl-3-methylimidazolium hexafluorophosphate ionic liquids ([Cnmim][PF6], n=4, 6, and 8). J Chem Phys 2010; 133:074510. [DOI: 10.1063/1.3473825] [Citation(s) in RCA: 257] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
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36
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Hardacre C, Holbrey JD, Mullan CL, Nieuwenhuyzen M, Youngs TGA, Bowron DT, Teat SJ. Solid and liquid charge-transfer complex formation between 1-methylnaphthalene and 1-alkyl-cyanopyridinium bis{(trifluoromethyl)sulfonyl}imide ionic liquids. Phys Chem Chem Phys 2010; 12:1842-53. [DOI: 10.1039/b921160h] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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37
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Jones SG, Yau HM, Davies E, Hook JM, Youngs TGA, Harper JB, Croft AK. Ionic liquids through the looking glass: theory mirrors experiment and provides further insight into aromatic substitution processes. Phys Chem Chem Phys 2010; 12:1873-8. [DOI: 10.1039/b919831h] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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38
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Abstract
We compare the properties of models of liquids and crystals constructed from a number of intermolecular potentials for dimethylimidazolium chloride [dmim][Cl]. The force fields differ in the charge distribution in the cation but all include short range interactions which determine the shape of the cation. In addition to 'realistic' models intended for simulation of [dmim][Cl] we take two extreme 'unrealistic' models in which the cation charge is localized on the ring atoms or at the ring centre in order to study the effects of the cation charge distribution. The effects of polarizability are investigated by using shell models for the chloride ion. We find that, while equilibrium properties such as energetics, crystal structure, liquid structure and charge screening depend on the charge distribution in the cation but are little affected by including polarizability, dynamical properties such as diffusion are strongly affected by polarizability.
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Affiliation(s)
- R M Lynden-Bell
- Department of Chemistry, Lensfield Road, Cambridge CB2 1EW, UK
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39
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Youngs TGA, Hardacre C. Application of static charge transfer within an ionic-liquid force field and its effect on structure and dynamics. Chemphyschem 2008; 9:1548-58. [PMID: 18613196 DOI: 10.1002/cphc.200800200] [Citation(s) in RCA: 166] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The effects of linear scaling of the atomic charges of a reference potential on the structure, dynamics, and energetics of the ionic liquid 1,3-dimethylimidazolium chloride are investigated. Diffusion coefficients that span over four orders of magnitude are observed between the original model and a scaled model in which the ionic charges are +/-0.5 e. While the three-dimensional structure of the liquid is less affected, the partial radial distribution functions change markedly--with the positive result that for ionic charges of +/-0.7 e, an excellent agreement is observed with ab initio molecular dynamics data. Cohesive energy densities calculated from these partial-charge models are also in better agreement with those calculated from the ab initio data. We postulate that ionic-liquid models in which the ionic charges are assumed to be +/-1 e overestimate the intermolecular attractions between ions, which results in overstructuring, slow dynamics, and increased cohesive energy densities. The use of scaled-charge sets may be of benefit in the simulation of these systems--especially when looking at properties beyond liquid structure--thus providing an alternative to computationally expensive polarisable force fields.
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Affiliation(s)
- Tristan G A Youngs
- Atomistic Simulation Centre, School of Maths and Physics, Queen's University Belfast, Belfast, BT7 1NN, UK.
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40
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Youngs TGA, Hardacre C. Cover Picture: Application of Static Charge Transfer within an Ionic-Liquid Force Field and Its Effect on Structure and Dynamics (ChemPhysChem 11/2008). Chemphyschem 2008. [DOI: 10.1002/cphc.200890044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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41
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Hardacre C, Holbrey JD, Mullan CL, Nieuwenhuyzen M, Youngs TGA, Bowron DT. Liquid Structure of the Ionic Liquid, 1-Methyl-4-cyanopyridinium Bis{(trifluoromethyl)sulfonyl}imide Determined from Neutron Scattering and Molecular Dynamics Simulations. J Phys Chem B 2008; 112:8049-56. [DOI: 10.1021/jp801801j] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Christopher Hardacre
- School of Chemistry and Chemical Engineering/School of Mathematics and Physics, The QUILL Centre, Queen’s University Belfast, Belfast BT9 5AG, United Kingdom, and Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX, United Kingdom
| | - John D. Holbrey
- School of Chemistry and Chemical Engineering/School of Mathematics and Physics, The QUILL Centre, Queen’s University Belfast, Belfast BT9 5AG, United Kingdom, and Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX, United Kingdom
| | - Claire L. Mullan
- School of Chemistry and Chemical Engineering/School of Mathematics and Physics, The QUILL Centre, Queen’s University Belfast, Belfast BT9 5AG, United Kingdom, and Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX, United Kingdom
| | - Mark Nieuwenhuyzen
- School of Chemistry and Chemical Engineering/School of Mathematics and Physics, The QUILL Centre, Queen’s University Belfast, Belfast BT9 5AG, United Kingdom, and Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX, United Kingdom
| | - Tristan G. A. Youngs
- School of Chemistry and Chemical Engineering/School of Mathematics and Physics, The QUILL Centre, Queen’s University Belfast, Belfast BT9 5AG, United Kingdom, and Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX, United Kingdom
| | - Daniel T. Bowron
- School of Chemistry and Chemical Engineering/School of Mathematics and Physics, The QUILL Centre, Queen’s University Belfast, Belfast BT9 5AG, United Kingdom, and Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX, United Kingdom
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42
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Yau HM, Barnes SA, Hook JM, Youngs TGA, Croft AK, Harper JB. The importance of solvent reorganisation in the effect of an ionic liquid on a unimolecular substitution process. Chem Commun (Camb) 2008:3576-8. [DOI: 10.1039/b805255g] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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43
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Abstract
This Account describes experimental data used to understand the structure of ionic liquids and solute-solvent interactions of both molecular solutes and dissolved metal complexes. In general, the structures of the ionic liquids determined from experimental data show good agreement with both simulated structures and solid-state structures. For all ionic liquids studied, strong charge ordering is found leading to long-range order even in the presence of a solute. For dissolved metal complexes, the ionic liquid is not innocent and a clear dependence on the speciation is observed with variations in both the cation and anion.
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Affiliation(s)
- Christopher Hardacre
- School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast BT9 5AG, UK.
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44
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Lynden-Bell RM, Del Pópolo MG, Youngs TGA, Kohanoff J, Hanke CG, Harper JB, Pinilla CC. Simulations of ionic liquids, solutions, and surfaces. Acc Chem Res 2007; 40:1138-45. [PMID: 17914887 DOI: 10.1021/ar700065s] [Citation(s) in RCA: 246] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We have been using atomistic simulation for the last 10 years to study properties of imidazolium-based ionic liquids. Studies of dissolved molecules show the importance of electrostatic interactions in both aromatic and hydrogen-bonding solutes. However, the local structure strongly depends upon ion-ion and solute-solvent interactions. We find interesting local alignments of cations at the gas-liquid and solid-liquid interfaces, which give a potential drop through the surface. If the solid interface is charged, this charge is strongly screened over distances of a few nanometres and this screening decays on a fast time scale. We have studied the sensitivity of the liquid structure to force-field parameters and show that results from ab initio simulations can be used in the development of force fields.
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Affiliation(s)
- Ruth M Lynden-Bell
- Atomistic Simulation Centre, School of Mathematics and Physics, Queen's University, Belfast BT7 1NN, United Kingdom.
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45
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Youngs TGA, Holbrey JD, Deetlefs M, Nieuwenhuyzen M, Costa Gomes MF, Hardacre C. A Molecular Dynamics Study of Glucose Solvation in the Ionic Liquid 1,3-Dimethylimidazolium Chloride. Chemphyschem 2006; 7:2279-81. [PMID: 17086590 DOI: 10.1002/cphc.200600569] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Tristan G A Youngs
- Atomistic Simulation Centre/QUILL, School of Maths and Physics, Queen's University Belfast, BT7 1NN, UK.
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46
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Youngs TGA, Del Pópolo MG, Kohanoff J. Development of Complex Classical Force Fields through Force Matching to ab Initio Data: Application to a Room-Temperature Ionic Liquid. J Phys Chem B 2006; 110:5697-707. [PMID: 16539515 DOI: 10.1021/jp056931k] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Recent experimental neutron diffraction data and ab initio molecular dynamics simulation of the ionic liquid dimethylimidazolium chloride ([dmim]Cl) have provided a structural description of the system at the molecular level. However, partial radial distribution functions calculated from the latter, when compared to previous classical simulation results, highlight some limitations in the structural description offered by force field-based simulations. With the availability of ab initio data it is possible to improve the classical description of [dmim]Cl by using the force matching approach, and the strategy for fitting complex force fields in their original functional form is discussed. A self-consistent optimization method for the generation of classical potentials of general functional form is presented and applied, and a force field that better reproduces the observed first principles forces is obtained. When used in simulation, it predicts structural data which reproduces more faithfully that observed in the ab initio studies. Some possible refinements to the technique, its application, and the general suitability of common potential energy functions used within many ionic liquid force fields are discussed.
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Affiliation(s)
- Tristan G A Youngs
- Atomistic Simulation Centre, School of Physics, Queen's University, Belfast BT7 1NN, UK.
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47
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Hudson MJ, Boucher CE, Braekers D, Desreux JF, Drew MGB, Foreman MRSJ, Harwood LM, Hill C, Madic C, Marken F, Youngs TGA. New bis(triazinyl) pyridines for selective extraction of americium(iii). NEW J CHEM 2006. [DOI: 10.1039/b514108g] [Citation(s) in RCA: 145] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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48
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Aulenta F, Drew MGB, Foster A, Hayes W, Rannard S, Thornthwaite DW, Worrall DR, Youngs TGA. Synthesis and Characterization of Fluorescent Poly(aromatic amide) Dendrimers. J Org Chem 2004; 70:63-78. [PMID: 15624907 DOI: 10.1021/jo048799a] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The synthesis of a series of poly(aromatic amide) dendrimers up to the second generation is described herein. The AB(2) building block used throughout the synthesis of the dendrimers was the allyl ester of 3,5-diaminocinnamic acid, which has been synthesized from 3,5-dinitrobenzoic acid in good yield with use of a four-step procedure. Dendron synthesis was achieved via a convergent approach with use of a sequence of deprotection/coupling steps. Two commercially available alcohols, L-menthol and citronellol, were coupled to the AB(2) monomer by using an alkyl diacid spacer and two core units; 1,7-diaminoheptane and tris(2-aminoethyl)amine have been used to produce the final dendrimers. Characterization was carried out by NMR and IR spectroscopies, MALDI-TOF mass spectrometry, GPC, and DSC. The novel monomer and dendritic derivatives exhibited a strong fluorescence emission in the visible region (lambda approximately 500 nm) of the spectrum and a weak emission in the near-infrared (lambda approximately 850 nm) upon excitation in the near-UV region. The fluorescence emission characteristics were found to be solvent and dendrimer generation dependent.
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Affiliation(s)
- Francesca Aulenta
- School of Chemistry, The University of Reading, Whiteknights, Reading RG6 6AD, UK
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Drew MGB, Hill C, Hudson MJ, Iveson PB, Madic C, Vaillant L, Youngs TGA. Separation of lanthanides and actinides(iii) using tridentate benzimidazole, benzoxazole and benzothiazole ligands. NEW J CHEM 2004. [DOI: 10.1039/b314321j] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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50
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Drew MGB, Hill C, Hudson MJ, Iveson PB, Madic C, Youngs TGA. Solvent extraction and lanthanide complexation studies with new terdentate ligands containing two 1,3,5-triazine moieties. Dalton Trans 2004:244-51. [PMID: 15356719 DOI: 10.1039/b312582c] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The extracting agent 2,6-bis(4,6-di-pivaloylamino-1,3,5-triazin-2-yl)-pyridine (L(5)) in n-octanol was found, in synergy with 2-bromodecanoic acid, to give D(Am)/D(Eu) separation factors (SFs) between 2.4 and 3.7 when used to extract the metal ions from 0.02-0.12 M HNO(3). Slightly higher SFs (4-6) were obtained in the absence of the synergist when the ligand was used to extract Am(III) and Eu(III) from 0.98 M HNO(3). In order to investigate the possible nature of the extracted species crystal structures of L(5) and the complex formed between Yb(III) with 2,6-bis(4,6-di-amino-1,3,5-triazin-2-yl)-pyridine (L(4)) were also determined. The structure of L(5) shows 3 methanol solvent molecules all of which form 2 or 3 hydrogen bonds with triazine nitrogen atoms, amide nitrogen or oxygen atoms, or pyridine nitrogen atoms. However, L(5) is relatively unstable in metal complexation reactions and loses amide groups to form the parent tetramine L(4). The crystal structure of Yb(L(4))(NO(3))(3) shows ytterbium in a 9-coordinate environment being bonded to three donor atoms of the ligand and three bidentate nitrate ions. The solvent extraction properties of L(4) and L(5) are far inferior to those found for the 2,6-bis-(1,2,4-triazin-3-yl)-pyridines (L(1)) which have SF values of ca. 140 and theoretical calculations have been made to compare the electronic properties of the ligands. The electronic charge distribution in L(4) and L(5) is similar to that found in other terdentate ligands such as terpyridine which have equally poor extraction properties and suggests that the unique properties of L(1) evolve from the presence of two adjacent nitrogen atoms in the triazine rings.
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Affiliation(s)
- Michael G B Drew
- Department of Chemistry, The University, Whiteknights, Reading RG6 6AD, UK
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