86 results on '"John M. Slattery"'
Search Results
2. Ir I (η 4 -diene) precatalyst activation by strong bases: formation of an anionic Ir III tetrahydride
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Paven Kisten, Eric Manoury, Agustí Lledós, Adrian C. Whitwood, Jason M. Lynam, John M. Slattery, Simon B. Duckett, Rinaldo Poli, Department of Chemistry, University of York, Heslington, University of York [York, UK], Laboratoire de chimie de coordination (LCC), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Universitat Autònoma de Barcelona (UAB), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), CNRS, and European Project: 860322,H2020-EU.1.3.1.,H2020-MSCA-ITN-2019,CCIMC(2020) more...
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Inorganic Chemistry ,[CHIM.COOR]Chemical Sciences/Coordination chemistry - Abstract
International audience; The reaction between [IrCl(COD)]2 and dppe in a 1:2 ratio was investigated in detail under three different conditions. [IrCl(COD)(dppe)], 1, is formed at room temperature in the absence of base. In the presence of a strong base at room temperarture, hydride complexes that retain the carbocyclic ligand in the coordination sphere are generated. In isopropanol, 1 is converted into [IrH(1,2,5,6-η2:η2-COD)(dppe)] (2) on addition of KOtBu, with k12 = (1.11±0.02)·10-4 s-1, followed by reversible isomerisation to [IrH(1-κ-4,5,6-η3-C8H12)(dppe)] (3) with k23 = (3.4±0.2)·10-4 s-1 and k32 = (1.1±0.3)·10-5 s-1 to yield an equilibrium 5:95 mixture of 2 and 3. However, when no hydride source is present in the strong base (KOtBu in benzene or toluene), the COD ligand in 1 is deprotonated, followed by β-H elimination of an IrI-C8H11 intermediate, which leads to complex [IrH(1-κ-4,5,6-η3-C8H10)(dppe)] (4) selectively. This is followed by its reversible isomerisation to 5, which features a different relative orientation of the same ligands (k45 = (3.92±0.11)·10-4 s-1; k54 = (1.39±0.12)·10-4 s-1 in C6D6), to yield an equilibrated 32:68 mixture of 4 and 5. DFT calculations assisted in the full rationalization of the selectivity and mechanism of the reactions, yielding thermodynamic (equilibrium) and kinetic (isomerization barriers) parameters in excellent agreement with the experimental values. Finally, in the presence of KOtBu and isopropanol at 80 °C, 1 is tranformed selectively to K[IrH4(dppe)] (6), a salt of an anionic tetrahydride complex of IrIII. This product is also selectively generated from 2, 3, 4 and 5 and H2 at room temperature, but only when a strong base is present. These results provide an insight into the catalytic action of [IrCl(LL)(COD)] complexes in the hydrogenation of polar substrates in the presence of a base. more...
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- 2023
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Catalog
3. Insights into the Composition and Structural Chemistry of Gallium(I) Triflate
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Josef T. Boronski, Matthew P. Stevens, Bono IJzendoorn, Adrian C. Whitwood, and John M. Slattery
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Main‐Group Chemistry ,Chemistry(all) ,chemistry.chemical_element ,low-valent gallium ,Catalysis ,Coordination complex ,Reactivity (chemistry) ,Gallium ,Bimetallic strip ,X-ray crystallography ,chemistry.chemical_classification ,Communication ,General Medicine ,General Chemistry ,Nuclear magnetic resonance spectroscopy ,Communications ,main-group chemistry ,Crystallography ,chemistry ,density functional calculations ,coordination chemistry ,Trifluoromethanesulfonate - Abstract
“GaOTf” is a simple, convenient source of low‐valent gallium for synthetic chemistry and catalysis. However, little is currently known about its composition or reactivity. In this work, 71Ga NMR spectroscopy shows the presence of [Ga(arene)n]+ salts on oxidation of Ga metal with AgOTf in arene solvents. However, a more complex picture of speciation is uncovered by X‐ray diffraction studies. In all cases, mixed‐valence compounds containing Ga‐arene and Ga‐OTf coordination motifs, in addition to an unusual “naked” [Ga]+ ion, are found. Addition of 18‐crown‐6 allows for the isolation of a discrete GaI crown complex. Evidence of a potential intermediate in the formation of “GaOTf” has been isolated in the form of the bimetallic silver(I)/gallium(I) cluster anion [Ag4{Ga(OTf)3}4(μ‐Ga)6(OTf)4]2−., Gallium(I) triflate is a promising new source of low‐valent gallium for synthesis and catalysis. However, little is known about its composition and structural chemistry. Here it is demonstrated that speciation is quite complex in this system, with compounds containing Ga in multiple oxidation states being isolated from arene solutions. more...
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- 2020
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4. Small-angle neutron scattering from mixtures of long- and short-chain 3-alkyl-1-methyl imidazolium bistriflimides
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Christopher P. Cabry, Lucía D’Andrea, Naomi S. Elstone, Sarah Kirchhecker, Alessio Riccobono, Iman Khazal, Peixun Li, Sarah E. Rogers, Duncan W. Bruce, and John M. Slattery
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General Physics and Astronomy ,Physical and Theoretical Chemistry - Abstract
The preparation of mixtures of ionic liquids (ILs) represents an attractive strategy to tune their properties, an important aspect of which is to understand how the structure of the bulk varies with composition. In this study, small-angle neutron scattering (SANS) was used to probe mixtures of methylimidazolium-based ionic liquids [Cnmim][Tf2N] with [C2mim][Tf2N]) (n = 4, 6, 8 and 10) and of [Cmmim][Tf2N] with [C12mim][Tf2N] (m = 2, 4, 6 and 8). Mixtures were prepared in both contrasts, which is to say that one component would be fully hydrogenated while the other was fully deuterated, and vice versa. Data were fitted using a range of appropriate models, of which the Teubner-Strey model provided most useful information and the pure materials showed a nascent Polar Non-polar Peak (PNPP) for n = 6, which became more evident as n increased. In the mixtures [Cnmim]x[C2mim]1−x[Tf2N], the PNPP was evident for n = 10 and 8, nascent for n = 6 and absent for n = 4, with percolation showing a very strong dependence on the chain length of the added IL, [Cnmim][Tf2N]. In contrast, while the ability of [C12mim][Tf2N] to form percolated structures was damped when mixed with [Cmmim][Tf2N], as m increased from 2 to 6, this effect was less strong. However, data obtained for mixtures of [C12mim][Tf2N] and [C8mim][Tf2N], both of which percolate as pure materials, did not fit easily in any of the models applied to the previous systems and gave results that depended on the contrast used. Complementary small-angle X-ray scattering (SAXS) data, however, showed the expected evolution and behaviour of the PNPP, COP and CP, revealing that the unexpected observations were due to an adventitious matching out of isotopic contrasts. As well as revealing details of the structures of these IL mixtures, the results also point to complementary strategies for generating bulk percolated structures as a function of cation chain length. more...
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- 2022
5. Surface Structure of Alkyl/Fluoroalkylimidazolium Ionic-Liquid Mixtures
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Simon M. Purcell, Paul D. Lane, Lucía D’Andrea, Naomi S. Elstone, Duncan W. Bruce, John M. Slattery, Eric J. Smoll, Stuart J. Greaves, Matthew L. Costen, Timothy K. Minton, and Kenneth G. McKendrick
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Materials Chemistry ,Physical and Theoretical Chemistry ,Surfaces, Coatings and Films - Abstract
The gas-liquid interface of ionic liquids (ILs) is critically important in many applications, for example, in supported IL phase (SILP) catalysis. Methods to investigate the interfacial structure in these systems will allow their performance to be improved in a rational way. In this study, reactive-atom scattering (RAS), surface tension measurements, and molecular dynamics (MD) simulations were used to study the vacuum interface of mixtures of partially fluorinated and normal alkyl ILs. The underlying aim was to understand whether fluorinated IL ions could be used as additives to modify the surface structure of one of the most widely used families of alkyl ILs. The series of ILs 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C more...
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- 2022
6. Building blocks for the chemistry of perfluorinated alkoxyaluminates [Al{OC(CF3)3}4]−: simplified preparation and characterization of Li+–Cs+, Ag+, NH4+, N2H5+ and N2H7+ salts
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Ingo Krossing, Manuel Schmitt, John M. Slattery, Tomasz Jaroń, Przemysław J. Malinowski, and Małgorzata Domańska
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Inorganic Chemistry ,Monovalent Cations ,Primary (chemistry) ,Chemistry ,Physical chemistry ,Thermal stability ,Improved method ,Crystal structure ,Solubility ,Ion ,Characterization (materials science) - Abstract
Advanced weakly coordinating anions (WCAs) significantly facilitate synthesis of various exotic chemical compounds and novel, potentially useful materials. One of such anions - [Al{OC(CF3)3}4]-, denoted [Al(ORF)4]-, appears particularly convenient, as it can be easily prepared from the commercially available alanates and HOC(CF3)3. Here we present a thorough characterization of a series of solvent-free M[Al(ORF)4] salts, M = Li-Cs, Ag, NH4, N2H5 and N2H7, and related compounds of monovalent cations, which are crucial starting materials for further work with these species. Notably, the corresponding synthetic protocols are updated by an improved method for fast, facile and easily scalable synthesis of Li[Al(ORF)4], which remains the most useful primary source of the anion. The physico-chemical properties of these salts including crystal structures, thermal stability by TG/DSC, vibrational spectra as well as solubility are discussed in a systematic fashion. more...
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- 2020
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7. Probing a Ruthenium Coordination Complex at the Ionic Liquid–Vacuum Interface with Reactive-Atom Scattering, X-ray Photoelectron Spectroscopy, and Time-of-Flight Secondary Ion Mass Spectrometry
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John M. Slattery, Lucia D'Andrea, Timothy K. Minton, Lewis M. Hall, Ximeng Chen, and Eric J. Smoll
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chemistry.chemical_classification ,Materials science ,chemistry.chemical_element ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Coordination complex ,Ruthenium ,Secondary ion mass spectrometry ,Time of flight ,chemistry.chemical_compound ,General Energy ,chemistry ,X-ray photoelectron spectroscopy ,Transition metal ,Ionic liquid ,Physical chemistry ,Reactivity (chemistry) ,Physical and Theoretical Chemistry - Abstract
The speciation, conformation, and reactivity of transition metal complexes at the gas–liquid interface are poorly understood, yet the potential is high for observing chemistry unique to this anisot... more...
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- 2019
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8. Solvent effects in palladium catalysed cross-coupling reactions
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John M. Slattery, Ian J. S. Fairlamb, James H. Clark, and James Sherwood
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010405 organic chemistry ,Chemistry ,Negishi coupling ,chemistry.chemical_element ,Sonogashira coupling ,010402 general chemistry ,01 natural sciences ,Pollution ,Combinatorial chemistry ,Coupling reaction ,0104 chemical sciences ,Catalysis ,Stille reaction ,Solvent ,Environmental Chemistry ,Solvent effects ,Palladium - Abstract
Palladium catalysed cross-couplings reactions have been a dominant method in synthetic chemistry for decades. Despite this, the role of the solvent is often taken for granted and poorly understood. Regulations affecting some the most frequently used solvents for cross-coupling reactions are accelerating current trends towards using new types of solvents. In this review, the fundamental interactions between solvent and catalyst are explained so that it may inform the rational selection of high performance and safe solvents. The popular cross-coupling methodologies are addressed (Suzuki, Stille, Kumada, Negishi, Hiyama, Heck, Sonogashira, and Buchwald–Hartwig reactions) and novel solvents introduced. more...
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- 2019
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9. Physical methods for mechanistic understanding: general discussion
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Jonathan D. Wilden, Simone Gallarati, Jennifer A. Love, David J. Nelson, Samuel Scott, Thomas Braun, David Schilter, Matthias Bauer, Aaron L. Odom, David L. Davies, Robert H. Morris, Vidar R. Jensen, Tolga Yaman, Jana Roithova, Yutaka Aoki, Kevin R. J. Lovelock, Alexander J Hamilton, Evert Jan Meijer, Jason M. Lynam, James W. Walton, Meghan E. Halse, Alison N. Hulme, Joseph S. Renny, Youichi Ishii, Shigeki Kuwata, Robin N. Perutz, Stuart MacGregor, Aiwen Lei, Laurel L. Schafer, Jamie A. Cadge, Martin Jakoobi, John M. Slattery, Todd B. Marder, Derek J. Durand, Ian J. S. Fairlamb, Guy C. Lloyd-Jones, Pierre Kennepohl, Natalie Fey, M. George, Odile Eisenstein, Ulrich Hintermair, Anthony Haynes, Megan Greaves, Markus Reiher, Jeremy N. Harvey, Daniel H. Ess, Patrick Morgan, Joseph M. Mwansa, Tom A. Young, Chun-Yuen Wong, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Brigham Young University (BYU), Department of Chemistry [York, UK], University of York [York, UK], University of Bristol [Bristol], Department of Chemistry, University of Bergen (UiB), Medical Informatics Division, Tottori University Hospital, Heriot-Watt University [Edinburgh] (HWU), University of Würzburg, Universiteit van Amsterdam (UvA), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Department of Organic Chemistry [Prague], University of Chemistry and Technology Prague (UCT Prague), Department of Chemistry [Vancouver] (UBC Chemistry), University of British Columbia (UBC), and Center for Multidimensional Carbon Materials, Institute for Basic Science (IBS) (CMCM) more...
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h-2 ,spectroscopy ,02 engineering and technology ,spin states ,ligand ,010402 general chemistry ,01 natural sciences ,PI-SYMMETRY ,ABSORPTION ,Physical and Theoretical Chemistry ,CARBON-MONOXIDE ,ComputingMilieux_MISCELLANEOUS ,SPIN STATES ,H-2 ,Cognitive science ,CATALYST ,complexes ,Science & Technology ,SPECTROSCOPY ,Chemistry, Physical ,carbon-monoxide ,[CHIM.CATA]Chemical Sciences/Catalysis ,HYDROGEN ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,Chemistry ,pi-symmetry ,hydrogen ,Physical Sciences ,COMPLEXES ,LIGAND ,0210 nano-technology ,Psychology ,absorption ,catalyst - Abstract
ispartof: FARADAY DISCUSSIONS vol:220 issue:0 pages:144-178 ispartof: location:England status: published
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- 2019
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10. Building blocks for the chemistry of perfluorinated alkoxyaluminates [Al{OC(CF
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Przemysław J, Malinowski, Tomasz, Jaroń, Małgorzata, Domańska, John M, Slattery, Manuel, Schmitt, and Ingo, Krossing
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Advanced weakly coordinating anions (WCAs) significantly facilitate synthesis of various exotic chemical compounds and novel, potentially useful materials. One of such anions - [Al{OC(CF
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- 2020
11. Determining the composition of the vacuum–liquid interface in ionic-liquid mixtures
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Maria Antonia Tesa-Serrate, Kenneth G. McKendrick, John M. Slattery, Matthew L. Costen, Timothy K. Minton, Simon Purcell, Lucia D'Andrea, Duncan W. Bruce, and Eric J. Smoll
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Scattering ,Analytical chemistry ,Raoult's law ,Langmuir adsorption model ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Mole fraction ,01 natural sciences ,0104 chemical sciences ,Ion ,Surface tension ,Molecular dynamics ,chemistry.chemical_compound ,symbols.namesake ,chemistry ,Ionic liquid ,symbols ,Physical and Theoretical Chemistry ,0210 nano-technology - Abstract
The vacuum–liquid interfaces of a number of ionic-liquid mixtures have been investigated using the combination of reactive-atom scattering with laser-induced fluorescence detection (RAS-LIF), selected surface tension measurements, and molecular dynamics (MD) simulations. The mixtures are based on the widespread 1-alkyl-3-methylimidazolium ([Cnmim]+) cation, including mixed cations which differ in chain length or chemical functionality with a common anion; and different anions for a common cation. RAS-LIF results imply that the surface compositions exhibit a general form of non-stoichiometric behaviour that mimics the well-known Henry’s and Raoult’s laws at low and high mole fraction, respectively. The extended Langmuir model provides a moderately good single-parameter fit, but higher-order terms are required for an accurate description. The quantitative relationship between RAS-LIF and surface tension, which probes the surface composition only indirectly, is explored for mixtures of [C2mim]+ and [C12mim]+ with a common bis(trifluoromethylsulfonyl)imide ([NTf2]−) anion. Extended Langmuir model fits to surface tension data are broadly consistent with those to RAS-LIF; however, several other common approaches to extracting surface compositions from measured surface tensions result in much larger discrepancies. MD simulations suggest that RAS-LIF faithfully reports on the alkyl-chain exposure at the surface, which is only subtly modified by composition-dependent structural reorganisation. more...
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- 2018
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12. 1,2,4-Triazolium ions as flexible scaffolds for the construction of polyphilic ionic liquid crystals
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Alessio Riccobono, Rachel R. Parker, Duncan W. Bruce, Andrea Pace, John M. Slattery, Adrian C. Whitwood, Ivana Pibiri, Riccobono, Alessio, Parker, Rachel R., Whitwood, Adrian C., Slattery, John M., Bruce, Duncan W., Pibiri, Ivana, and Pace, Andrea more...
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Materials Chemistry2506 Metals and Alloys ,Materials science ,Surfaces, Coatings and Film ,chemistry.chemical_element ,Ceramics and Composite ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Catalysis ,Catalysi ,Ion ,chemistry.chemical_compound ,Phase (matter) ,Materials Chemistry ,chemistry.chemical_classification ,Electronic, Optical and Magnetic Material ,Chemistry (all) ,Metals and Alloys ,General Chemistry ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Chain length ,Hydrocarbon ,chemistry ,Chemical engineering ,Ionic liquid ,Ceramics and Composites ,Fluorine ,0210 nano-technology - Abstract
A novel scaffold for the construction of self-organised ionic liquids and ionic liquid crystals bearing both perfluorocarbon and hydrocarbon moieties has been developed. The phase behaviour and physical properties of these materials can be tuned as a function of chain length and fluorine content and significant structural elaboration is possible, giving a highly flexible system. more...
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- 2018
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13. Exploring the bulk-phase structure of ionic liquid mixtures using small-angle neutron scattering
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John M. Slattery, Peixun Li, Duncan W. Bruce, Christopher P. Cabry, Karina Shimizu, Sarah E. Rogers, Lucia D'Andrea, José N. Canongia Lopes, and Isabelle Grillo
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Scattering ,Analytical chemistry ,02 engineering and technology ,Neutron scattering ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Small-angle neutron scattering ,0104 chemical sciences ,Ion ,chemistry.chemical_compound ,Molecular dynamics ,chemistry ,Phase (matter) ,Ionic liquid ,Polar ,Physical and Theoretical Chemistry ,0210 nano-technology - Abstract
Small-angle neutron scattering experiments, supported by molecular dynamics simulations, have been performed on a range of compositions of the [C2mim]1−x[C12mim]x[Tf2N] ionic liquid mixture system. Isotopic contrast variation, through selective deuteration of both cations, has been used to assist in fitting the data to different scattering models. These data, and subsequent fitting, show that the structure of the ionic liquid mixtures changes substantially as a function of composition. Mixtures where x < 0.32 are dominated by aggregates of amphiphilic [C12mim]+ ions in the relatively polar [C2mim][Tf2N] solvent. Compositions where x > 0.32 can be described as bicontinuous, containing networks of both polar and non-polar domains, where the C12 chains of the [C12mim]+ ions percolate through the system to form a continuous non-polar sub-phase. Temperature-dependent scattering experiments suggest that there is relatively little change in bulk structure in these liquids between 20 and 60 °C. The presence of water, however, does influence some aspects of the liquid structure in a composition that is rich in [C2mim][Tf2N] (where x = 0.24). more...
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- 2018
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14. Mechanistic insight into organic and industrial transformations: general discussion
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Joseph S. Renny, Alison N. Hulme, James W. Walton, Markus Reiher, Jeremy N. Harvey, Aaron L. Odom, Jason M. Lynam, Odile Eisenstein, Shigeki Kuwata, Jana Roithova, Martin Jakoobi, George E Clarke, Robin N. Perutz, Anthony Haynes, Laurel L. Schafer, David J. Nelson, Stuart MacGregor, Matthias Bauer, Youichi Ishii, Yutaka Aoki, Toshiro Takao, Peter W. Seavill, Thomas Braun, Simone Gallarati, Megan Greaves, Guy C. Lloyd-Jones, Jennifer A. Love, Tom A. Young, Jamie A. Cadge, John M. Slattery, Jonathan D. Wilden, Chun-Yuen Wong, Pierre Kennepohl, Aiwen Lei, Derek J. Durand, Samuel Scott, Robert H. Morris, Vidar R. Jensen, Ulrich Hintermair, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), University of Bergen (UiB), Medical Informatics Division, Tottori University Hospital, Heriot-Watt University [Edinburgh] (HWU), Department of Chemistry [York, UK], University of York [York, UK], Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Department of Organic Chemistry [Prague], University of Chemistry and Technology Prague (UCT Prague), Department of Chemistry [Vancouver] (UBC Chemistry), and University of British Columbia (UBC) more...
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ab-initio ,mono-oxidation ,complexes ,ligands ,010405 organic chemistry ,Chemistry ,[CHIM.CATA]Chemical Sciences/Catalysis ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,reactivity ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,phosphines ,challenge ,Spectroscopy and Catalysis ,donor properties ,activation ,Biochemical engineering ,solvation ,Physical and Theoretical Chemistry ,ComputingMilieux_MISCELLANEOUS - Abstract
Contains fulltext : 215022.pdf (Publisher’s version ) (Open Access)
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- 2019
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15. Understanding unusual element-element bond formation and activation: general discussion
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Thomas Braun, Youichi Ishii, Joseph M. Mwansa, John M. Slattery, Alexander J Hamilton, Odile Eisenstein, Gilian T. Thomas, Jason M. Lynam, David L. Davies, Christopher Goult, Markus Reiher, Chun-Yuen Wong, Zhiliang Huang, Robin N. Perutz, Natalie Fey, Patrick Morgan, Guy C. Lloyd-Jones, Martin Jakoobi, Todd B. Marder, Stuart MacGregor, Maria Talavera, Shigeki Kuwata, Yutaka Aoki, Ian J. S. Fairlamb, M. George, Jennifer A. Love, Aaron L. Odom, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Department of Chemistry [York, UK], University of York [York, UK], University of Bristol [Bristol], Medical Informatics Division, Tottori University Hospital, Heriot-Watt University [Edinburgh] (HWU), University of Würzburg, Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Hospital Universitario Ramón y Cajal [Madrid], and Universidad de Alcalá - University of Alcalá (UAH) more...
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Materials science ,Thermodynamics ,02 engineering and technology ,[CHIM.CATA]Chemical Sciences/Catalysis ,Bond formation ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,[CHIM]Chemical Sciences ,Physical and Theoretical Chemistry ,Element (category theory) ,0210 nano-technology ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
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- 2019
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16. Computational and theoretical approaches for mechanistic understanding: general discussion
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Alison N. Hulme, Matthias Bauer, Aaron L. Odom, Natalie Fey, Robin N. Perutz, Markus Reiher, Robert H. Morris, Vidar R. Jensen, Jeremy N. Harvey, Daniel H. Ess, Odile Eisenstein, Todd B. Marder, Patrick Morgan, Jamie A. Cadge, John M. Slattery, Alexander J Hamilton, Guy C. Lloyd-Jones, Evert Jan Meijer, Youichi Ishii, Ulrich Hintermair, Stuart MacGregor, Simone Gallarati, Jennifer A. Love, Laurel L. Schafer, David L. Davies, Derek J. Durand, Joseph M. Mwansa, Tom A. Young, Jason M. Lynam, M. George, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Brigham Young University (BYU), University of Bristol [Bristol], University of Bergen (UiB), Heriot-Watt University [Edinburgh] (HWU), University of Würzburg, Universiteit van Amsterdam (UvA), Department of Chemistry [York, UK], University of York [York, UK], Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Department of Chemistry [Vancouver] (UBC Chemistry), and University of British Columbia (UBC) more...
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Science & Technology ,010405 organic chemistry ,Computer science ,Management science ,Chemistry, Physical ,boronic acid ,C-H ACTIVATION ,BORONIC ACID ,c-h activation ,[CHIM.CATA]Chemical Sciences/Catalysis ,BASE ,exploration ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,EXPLORATION ,Chemistry ,MOLECULES ,Physical Sciences ,[CHIM]Chemical Sciences ,molecules ,base ,Physical and Theoretical Chemistry ,ComputingMilieux_MISCELLANEOUS - Abstract
ispartof: FARADAY DISCUSSIONS vol:220 issue:0 pages:464-488 ispartof: location:England status: published
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- 2019
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17. Hiding the Headgroup? Remarkable Similarity in Alkyl Coverage of the Surfaces of Pyrrolidinium- and Imidazolium-Based Ionic Liquids
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Maria Antonia Tesa-Serrate, Kenneth G. McKendrick, Matthew L. Costen, Simon Purcell, Lucia D'Andrea, Duncan W. Bruce, John M. Slattery, Eric J. Smoll, and Timothy K. Minton
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chemistry.chemical_classification ,Stereochemistry ,Scattering ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Ring (chemistry) ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Ion ,Crystallography ,chemistry.chemical_compound ,Molecular dynamics ,General Energy ,chemistry ,Yield (chemistry) ,Ionic liquid ,Physical and Theoretical Chemistry ,0210 nano-technology ,Imide ,Alkyl - Abstract
The liquid–vacuum interfaces of a series of ionic liquids (ILs) containing 1-alkyl-1-methylpyrrolidinium ([Cnmpyrr]+) cations of different alkyl chain lengths have been studied by reactive-atom scattering with laser-induced fluorescence detection (RAS-LIF) and molecular dynamics (MD) simulations. A direct, quantitative comparison has been performed between [Cnmpyrr]+ and the previously better-characterized 1-alkyl-3-methylimidazolium ([Cnmim]+) ILs with the same chain lengths, n, and common anion, bis(trifluoromethylsulfonyl)imide ([Tf2N]−). Both RAS-LIF experiments, using O(3P) as the projectile and monitoring OH yield, and MD simulations indicate that the coverage of the surface by alkyl chains is almost independent of the identity of the cation headgroup. Moreover, the potentially abstractable H atoms of the saturated pyrrolidinium ring do not contribute appreciably to the experimental OH yield. In both these senses, therefore, the headgroup is “hidden” from the probe particles approaching from vacuum.... more...
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- 2016
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18. Reactive-Atom Scattering from Liquid Crystals at the Liquid–Vacuum Interface: [C12mim][BF4] and 4-Cyano-4′-Octylbiphenyl (8CB)
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John M. Slattery, Maria Antonia Tesa-Serrate, Lucia D'Andrea, Simon Purcell, Timothy K. Minton, Duncan W. Bruce, Eric J. Smoll, Kenneth G. McKendrick, Matthew L. Costen, and Brooks C. Marshall
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chemistry.chemical_classification ,Phase boundary ,Tetrafluoroborate ,Materials science ,Scattering ,02 engineering and technology ,Surfaces and Interfaces ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Condensed Matter::Soft Condensed Matter ,chemistry.chemical_compound ,Crystallography ,chemistry ,Liquid crystal ,Phase (matter) ,Atom ,Ionic liquid ,Electrochemistry ,General Materials Science ,0210 nano-technology ,Spectroscopy ,Alkyl - Abstract
Two complementary approaches were used to study the liquid–vacuum interface of the liquid-crystalline ionic liquid 1-dodecyl-3-methylimidazolium tetrafluoroborate ([C12mim][BF4]) in the smectic A (SmA) and isotropic phases. O atoms with two distinct incident translational energies were scattered from the surface of [C12mim][BF4]. Angle-dependent time-of-flight distributions and OH yields, respectively, were recorded from high- and low-energy O atoms. There were no significant changes in the measurements using either approach, nor the properties derived from them, accompanying the transition from the SmA to the isotropic phase. This indicates that the surface structure of [C12mim][BF4] remains essentially unchanged across the phase boundary, implying that the bulk order and surface structure are not strongly correlated for this material. This effect is ascribed to the strong propensity for the outer surfaces of ionic liquids to be dominated by alkyl chains, over an underlying layer rich in anions and catio... more...
- Published
- 2016
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19. Synthesis and mesomorphism of related series of triphilic ionic liquid crystals based on 1,2,4-triazolium cations
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Ivana Pibiri, Alessio Riccobono, John M. Slattery, Andrea Pace, Sarah E. Rogers, Duncan W. Bruce, Giuseppe Lazzara, Riccobono A., Lazzara G., Rogers S.E., Pibiri I., Pace A., Slattery J.M., and Bruce D.W. more...
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Thermogravimetric analysis ,Tetrafluoroborate ,Materials science ,Impedance spectroscopy ,Ionic bonding ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Settore CHIM/12 - Chimica Dell'Ambiente E Dei Beni Culturali ,chemistry.chemical_compound ,Liquid crystal ,Materials Chemistry ,Thermal stability ,Bistriflimide ,Physical and Theoretical Chemistry ,Spectroscopy ,SANS ,SAXS ,Settore CHIM/06 - Chimica Organica ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Crystallography ,Triphilic ,chemistry ,Ionic liquid ,Ionic liquid crystal ,0210 nano-technology ,Trifluoromethanesulfonate - Abstract
The synthesis, liquid crystal and conductivity properties of a series of 27 salts based on the 5-(4-(alkyloxy)phenyl)-1,2,4-triazol-4-ium cation bearing a perfluoroalkyl chain with triflate, tetrafluoroborate and bistriflimide anion are reported. The cations are regarded as triphilic on account of their three distinct regions – hydrocarbon, fluorocarbon and ionic. The mesophases were characterised by a combination of polarised optical microscopy, calorimetry and small-angle scattering experiments using both X-rays and neutrons, while thermal stability was probed using thermogravimetric analysis. The liquid crystal properties are found to be dependent on the anion and the length of the perfluorocarbon chain, which effects combine to determine aspects of the self-organisation in the mesophases. A strong dependence of conductivity on the anion is seen, which is in turn related to its charge density. more...
- Published
- 2021
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20. Probing Conformational Heterogeneity at the Ionic Liquid-Vacuum Interface by Reactive-Atom Scattering
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John M. Slattery, Kenneth G. McKendrick, Eric J. Smoll, Lucia D'Andrea, Matthew L. Costen, Simon Purcell, Duncan W. Bruce, and Timothy K. Minton
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Materials science ,Scattering ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Ring (chemistry) ,01 natural sciences ,0104 chemical sciences ,Condensed Matter::Soft Condensed Matter ,chemistry.chemical_compound ,chemistry ,Deuterium ,Chemical physics ,Yield (chemistry) ,Ionic liquid ,Atom ,Molecule ,General Materials Science ,Isotopologue ,Physical and Theoretical Chemistry ,0210 nano-technology - Abstract
The atomic-level description of liquid interfaces has lagged behind that of solid crystalline surfaces because existing experimental techniques have been limited in their capability to report molecular structure in a fluctuating liquid interfacial layer. We have moved toward a more detailed experimental description of the gas–liquid interface by studying the F-atom scattering dynamics on a common ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide. When given contrast by deuterium labeling, the yield and dynamical behavior of reactively scattered HF isotopologues can resolve distinct signatures from the cation butyl, methyl, and ring groups, which help to quantify the relative populations of cation conformations at the liquid–vacuum interface. These results demonstrate the importance of molecular organization in driving site-specific reactions at the extreme outer regions of the gas–liquid interface. more...
- Published
- 2018
21. Filling a niche in 'ligand space' with bulky, electron-poor phosphorus (III) alkoxides
- Author
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Adrian C. Whitwood, John M. Slattery, Tim James, Paul Beet, Jonathon Cottom, Denis Priester, Robert J. Thatcher, Sam Hart, and Sharifa Hussein
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chemistry.chemical_classification ,Steric effects ,010405 organic chemistry ,Ligand ,Phosphorus ,Organic Chemistry ,chemistry.chemical_element ,General Chemistry ,Electron ,010402 general chemistry ,01 natural sciences ,Combinatorial chemistry ,Catalysis ,0104 chemical sciences ,Coordination complex ,chemistry.chemical_compound ,chemistry ,Alkoxide ,Organometallic chemistry - Abstract
The chemistry of phosphorus(III) ligands, which are of key importance in coordination chemistry, organometallic chemistry and catalysis, is dominated by relatively electron-rich species. Many of the electron-poor P(III) ligands that are readily available have relatively small steric profiles. As such, there is a significant gap in “ligand space” where more sterically bulky, electron-poor P(III) ligands are needed. This contribution discusses the coordination chemistry, steric and electronic properties of P(III) ligands bearing highly fluorinated alkoxide groups of the general form PRn(ORF)3-n, where R = Ph, RF = C(H)(CF3)2 and C(CF3)3; n = 1-3. These ligands are simple to synthesize and a range of experimental and theoretical methods suggest that their steric and electronic properties can be “tuned” by modification of their substituents, making them excellent candidates for large, electron-poor ligands. more...
- Published
- 2018
22. Structure of Amido Pyridinium Betaines: Persistent Intermolecular C−H⋅⋅⋅N Hydrogen Bonding in Solution
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John M. Slattery, David G. Johnson, Robert J. Thatcher, and Richard E. Douthwaite
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Quantitative Biology::Biomolecules ,Halogen bond ,Hydrogen bond catalysis ,010405 organic chemistry ,Hydrogen bond ,Chemistry ,Organic Chemistry ,Inorganic chemistry ,Low-barrier hydrogen bond ,General Chemistry ,010402 general chemistry ,Hydrogen atom abstraction ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Crystallography ,Chemical bond ,Molecule ,Bond energy - Abstract
A hydrogen bond of the type C-H⋅⋅⋅X (X=O or N) is known to influence the structure and function of chemical and biological systems in solution. C-H⋅⋅⋅O hydrogen bonding in solution has been extensively studied, both experimentally and computationally, whereas the equivalent thermodynamic parameters have not been enumerated experimentally for C-H⋅⋅⋅N hydrogen bonds. This is, in part, due to the lack of systems that exhibit persistent C-H⋅⋅⋅N hydrogen bonds in solution. Herein, a class of molecule based on a biologically active norharman motif that exhibits unsupported intermolecular C-H⋅⋅⋅N hydrogen bonds in solution has been described. A pairwise interaction leads to dimerisation to give bond strengths of about 7 kJ mol-1 per hydrogen bond, which is similar to chemically and biologically relevant C-H⋅⋅⋅O hydrogen bonding. The experimental data is supported by computational work, which provides additional insight into the hydrogen bonding by consideration of electrostatic and orbital interactions and allowed a comparison between calculated and extrapolated NMR chemical shifts. more...
- Published
- 2016
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23. Advancement in knowledge of phenomena and processes: general discussion
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John M. Slattery, Chaohui Wei, Xianbo Jin, Paul A. Madden, Yiyang Kong, Qian Xu, Wei Xiao, John T. S. Irvine, Bin Dong, Andrew Doherty, Dihua Wang, Jennifer M. Pringle, Deshani H. A. T. Gunasekera, Han Wang, Ali Reza Kamali, Jianbang Ge, Babak Khalaghi, George Chen, Bencan Tang, Hongmin Zhu, Binjie Hu, Yingjun Liu, Linpo Yu, Yalan Liu, Toru H. Okabe, Ye Liu, Kathie McGregor, Juanyu Yang, Andrew S. Mount, and Ian Farnan more...
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Viscosity ,chemistry.chemical_compound ,Chemistry ,Ionic liquid ,Organic chemistry ,Graphite ,Physical and Theoretical Chemistry ,Molten salt ,Cellulose ,1-ethyl-3-methylimidazolium acetate ,Dissolution - Published
- 2016
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24. Ionic Liquid–Vacuum Interfaces Probed by Reactive Atom Scattering: Influence of Alkyl Chain Length and Anion Volume
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Brooks C. Marshall, Maria Antonia Tesa-Serrate, Eric J. Smoll, John M. Slattery, Kenneth G. McKendrick, Simon Purcell, Matthew L. Costen, and Timothy K. Minton
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chemistry.chemical_classification ,Tetrafluoroborate ,Scattering ,Inorganic chemistry ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Ion ,chemistry.chemical_compound ,General Energy ,chemistry ,Ionic liquid ,Atom ,Physical chemistry ,Physical and Theoretical Chemistry ,Imide ,Trifluoromethanesulfonate ,Alkyl - Abstract
The liquid–vacuum interfaces of a series of room-temperature ionic liquids (RTILs) containing the 1-alkyl-3-methylimidazolium cation ([Cnmim]) were investigated by reactive-atom scattering (RAS). The length of the alkyl chain (n = 4, 6, 8, and 12) and the anion type (bis(trifluoromethylsulfonyl)imide ([Tf2N]), trifluoromethanesulfonate ([OTf]), and tetrafluoroborate ([BF4])) were varied systematically to determine their effects on the preferential occupancy of the surface by alkyl chains. The experiments employed collisions with gas-phase, ground-state oxygen atoms, O(3P), generating OH and H2O products that revealed the abundance of abstractable H atoms at the liquid surface. Two complementary approaches with different O atom energies and detection methods were employed: we denote these RAS-laser-induced fluorescence (RAS-LIF) and RAS-mass spectrometry (RAS-MS). [Cnmim][BF4] RTILs were studied by both methods, giving consistent trends of strongly increasing alkyl coverage with chain length. Even for the ... more...
- Published
- 2015
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25. Design and synthesis of fluorescent 7-deazaadenosine nucleosides containing π-extended diarylacetylene motifs
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John M. Slattery, Christoph G. Baumann, Robert M. Edkins, Ian J. S. Fairlamb, Sara De Ornellas, and Andrew Beeby
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Models, Molecular ,Molecular Conformation ,Chemistry Techniques, Synthetic ,Biochemistry ,Tubercidin ,Electron Transport ,symbols.namesake ,chemistry.chemical_compound ,Computational chemistry ,Stokes shift ,Physics::Atomic and Molecular Clusters ,Moiety ,Physics::Chemical Physics ,Physical and Theoretical Chemistry ,Diphenylacetylene ,Quantum ,Fluorescent Dyes ,Quantitative Biology::Biomolecules ,Organic Chemistry ,Solvatochromism ,Charge (physics) ,Fluorescence ,chemistry ,Drug Design ,Intramolecular force ,symbols ,Quantum Theory - Abstract
C-modified 7-deazaadenosines containing a diphenylacetylene moiety have been synthesised using cross-coupling approaches. The C-modified nucleosides exhibit remarkable fluorescence properties, including high quantum yields. Solvatochromic studies show a near linear correlation between the Stokes shift and solvent polarity which is indicative of intramolecular charge transfer. DFT calculations have allowed us to correlate the experimentally observed photophysical properties with the calculated HOMO-LUMO energy gaps within a series of real and model compounds. more...
- Published
- 2015
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26. Evidence for a SN2-type pathway in the exchange of phosphines at a [PhSe]+centre
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Christopher A. Russell, Michael Green, Mairi F. Haddow, John M. Slattery, Laura C. Forfar, Sharifa Hussein, and Jason M. Lynam
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Models, Molecular ,Magnetic Resonance Spectroscopy ,Phosphines ,Chemistry ,Stereochemistry ,Aryl ,Cationic polymerization ,Thio ,Entropy of activation ,Electron donor ,Associative substitution ,Crystallography, X-Ray ,Medicinal chemistry ,Inorganic Chemistry ,Kinetics ,chemistry.chemical_compound ,Cations ,Organoselenium Compounds ,Thermodynamics ,SN2 reaction ,Phosphine - Abstract
A range of thio- and seleno-phosphonium cationic complexes [RE(PR'3)](+)[X](-) (R = Me, Ph; E = S, Se; X = GaCl4, SbF6) have been synthesised and structurally characterised. Reaction of [PhSPPh3][GaCl4] and [PhSePPh3][GaCl4] with P(t)Bu3 results in the ready transfer of the "RS(+)" and "RSe(+)" fragments from PPh3 to the stronger electron donor P(t)Bu3. NMR experiments combined with an Eyring analysis on the corresponding degenerate phosphine exchange reaction allowed the thermodynamic values for the phosphine exchange reaction of the sulfur cation (ΔH(‡) 18.7 ± 12.0 kJ mol(-1); ΔS(‡) -99.3 ± 36.3 J mol(-1) K(-1)) to be compared with the corresponding values (ΔH(‡) 2.4 ± 1.1 kJ mol(-1) and ΔS(‡) -58.1 ± 5.0 J mol(-1) K(-1)) for the [PhSePPh3](+) system. Importantly, the large negative entropy of activation and linear dependence on the rate of exchange are compatible with an SN2-type exchange process. This conclusion is supported by DFT calculations which confirm that the phosphine exchange process occurs via an associative mechanism. The rate of exchange was found to increase from sulfur to selenium and those with aryl substituents underwent exchange faster than those with alkyl substituents. more...
- Published
- 2015
- Full Text
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27. Phase behaviour and thermodynamics: general discussion
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Matthieu Gras, Benjamin Cross, Shraeddha Tiwari, Joshua Elias Samuel James Reid, Jeffrey C. Everts, Satyen Saha, Millicent A. Firestone, Andrew P. Abbott, Florian Maier, Susan Perkin, Magdalena Bendová, Seiji Tsuzuki, Rob Atkin, Ramesh L. Gardas, Hiroshi Abe, Morgan L. Thomas, Simon Halstead, Johan Jacquemin, Carin H.J.T. Dietz, Philip G. Jessop, Himani Medhi, John M. Slattery, Agilio A. H. Padua, Leigh Aldous, José N. Canongia Lopes, Masayoshi Watanabe, Matteo Busato, Betul Uralcan, Tamar L. Greaves, Tristan G. A. Youngs, Doug MacFarlane, James F. Wishart, Christopher Hardacre, John D. Holbrey, Markus Mezger, Jason B. Harper, Margarida F. Costa Gomes, Biological Laboratory, Nihon University, Institute of Chemical Process Fundamentals of the ASCR, Czech Republic, Centro de Quimica Estrutural (CQE), Instituto Superior Técnico, Universidade Técnica de Lisboa (IST), Institut de Chimie de Clermont-Ferrand (ICCF), SIGMA Clermont (SIGMA Clermont)-Institut de Chimie du CNRS (INC)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Laboratoire Interdisciplinaire de Physique [Saint Martin d’Hères] (LIPhy), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), School of Chemistry and Chemical Engineering (QUILL), Queen's University [Belfast] (QUB), Physico-chimie des Matériaux et des Electrolytes pour l'Energie (PCM2E), Université de Tours, School of Chemistry and Chemical Engineering [Belfast], Physical and Theoretical Chemistry Laboratory [Oxford], University of Oxford [Oxford], National Institute of Advanced Industrial Science and Technology (AIST), Yokohama National University, Université de Tours (UT), and University of Oxford more...
- Subjects
060201 languages & linguistics ,Chemistry ,Thermodynamics ,06 humanities and the arts ,02 engineering and technology ,Ionic liquids ,Phase (matter) ,0602 languages and literature ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,[PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph] ,Physical and Theoretical Chemistry ,[PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft] ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 2017
28. Nanosegregation and Structuring in the Bulk and at the Surface of Ionic-Liquid Mixtures
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Duncan W, Bruce, Christopher P, Cabry, José N Canongia, Lopes, Matthew L, Costen, Lucía, D'Andrea, Isabelle, Grillo, Brooks C, Marshall, Kenneth G, McKendrick, Timothy K, Minton, Simon M, Purcell, Sarah, Rogers, John M, Slattery, Karina, Shimizu, Eric, Smoll, and María A, Tesa-Serrate more...
- Abstract
Ionic-liquid (IL) mixtures hold great promise, as they allow liquids with a wide range of properties to be formed by mixing two common components rather than by synthesizing a large array of pure ILs with different chemical structures. In addition, these mixtures can exhibit a range of properties and structural organization that depend on their composition, which opens up new possibilities for the composition-dependent control of IL properties for particular applications. However, the fundamental properties, structure, and dynamics of IL mixtures are currently poorly understood, which limits their more widespread application. This article presents the first comprehensive investigation into the bulk and surface properties of IL mixtures formed from two commonly encountered ILs: 1-ethyl-3-methylimidazolium and 1-dodecyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C more...
- Published
- 2017
29. Univalent Gallium Salts of Weakly Coordinating Anions: Effective Initiators/Catalysts for the Synthesis of Highly Reactive Polyisobutylene
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John M. Slattery, Sarah C. Hughes, Dietmar A. Plattner, Alberto Steffani, Martin R. Lichtenthaler, Anne Kraft, Alexander Higelin, and Ingo Krossing
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Isobutylene ,chemistry.chemical_classification ,Double bond ,Organic Chemistry ,chemistry.chemical_element ,Toluene ,Catalysis ,Inorganic Chemistry ,Solvent ,chemistry.chemical_compound ,chemistry ,Polymerization ,Polymer chemistry ,Physical and Theoretical Chemistry ,Gallium ,Volume concentration - Abstract
The scope of the univalent gallium salts [Ga(C6H5F)2]+[Al(ORF)4]− and the new completely characterized [Ga(1,3,5-Me3C6H3)2]+[Al(ORF)4]− (RF = C(CF3)3) was investigated in terms of initiating or catalyzing the synthesis of highly reactive poly(2-methylpropylene)—highly reactive polyisobutylene (HR-PIB)—in several solvents. A series of polymerization reactions proved the high efficiency and quality of the univalent gallium salts for the polymerization of isobutylene. The best results were obtained using very low concentrations of [Ga(C6H5F)2]+[Al(ORF)4]− (down to 0.007 mol%) while working at reaction temperatures of up to ±0 °C and in the noncarcinogenic and non-water hazardous solvent toluene. Under these conditions, HR-PIB with an α-content of terminal olefinic double bonds up to 91 mol% and a molecular weight of 1000–2000 was obtained in good yields. Upon changing [Ga(C6H5F)2]+[Al(ORF)4]− for the electron richer [Ga(1,3,5-Me3C6H3)2]+[Al(ORF)4]−, polymerization temperatures could be increased to +10 °C. T... more...
- Published
- 2013
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30. A Structurally Characterized Fluoroalkyne
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Natalie E. Pridmore, Lewis M. Hall, David P. Tew, Adrian C. Whitwood, John M. Slattery, and Jason M. Lynam
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Deprotonation ,010405 organic chemistry ,Chemistry ,Stereochemistry ,Electrophile ,Electrophilic fluorination ,General Medicine ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences - Abstract
The facile synthesis of a stable and isolable compound with a fluoroalkynyl group, M−C≡CF, is reported. Reaction of [Ru(C≡CH)(η5-C5Me5)(dppe)] with an electrophilic fluorinating agent (NFSI) results in the formation of the fluorovinylidene complex [Ru(=C=CHF)(η5-C5Me5)(dppe)][N(SO2Ph)2]. Subsequent deprotonation with LiN(SiMe3)2 affords the fluoroalkynyl complex [Ru(C≡CF)(η5-C5Me5)(dppe)]. In marked contrast to the rare and highly reactive examples of fluoroalkynes that have been reported previously, this compound can be readily isolated and structurally characterized. This has allowed the structure and bonding in the CCF motif to be explored. Further electrophilic fluorination of this species yields the difluorovinylidene complex [Ru(C=CF2)(η5-C5Me5)(dppe)][N(SO2Ph)2]. more...
- Published
- 2017
31. Interactions in Water-Ionic Liquid Mixtures: Comparing Protic and Aprotic Systems
- Author
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Seishi Shimizu, Joshua Elias Samuel James Reid, Adam J. Walker, John M. Slattery, and Richard Gammons
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Inorganic chemistry ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,chemistry.chemical_compound ,chemistry ,Ionic liquid ,Materials Chemistry ,Organic chemistry ,Physical and Theoretical Chemistry ,0210 nano-technology ,Imide ,Water content ,Volume concentration - Abstract
The sensitivity of ionic liquids (ILs) to water affects their physical and chemical properties, even at relatively low concentrations, yet the structural thermodynamics of protic IL– (PIL−) water systems at low water concentrations still remains unclear. Using the rigorous Kirkwood–Buff theory of solutions, which can quantify the interactions between species in IL–water systems solely from thermodynamic data, we have shown the following: (1) Between analogous protic and aprotic ILs (AILs), the AIL cholinium bis(trifluoromethanesulfonyl)imide ([Ch][NTf2]) shows stronger interactions with water at low water concentrations, with the analogous PIL N,N-dimethylethanolammonium bis(trifluoromethanesulfonyl)imide ([DMEtA][NTf2]) having stronger water–ion interactions at higher water contents, despite water–ion interactions weakening with increasing water content in both systems. (2) Water has little effect on the average ion–ion interactions in both protic and aprotic ILs, aside from the AIL [Ch][NTf2], which sho... more...
- Published
- 2017
32. Highlights from liquid salts for energy and materials - Faraday Discussion, Ningbo, China, 11-13 May 2016
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John M. Slattery, Linpo Yu, George Chen, Xianbo Jin, Bamidele Akinwolemiwa, and Di Hu
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Materials science ,Metals and Alloys ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Engineering physics ,Catalysis ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,law.invention ,law ,Materials Chemistry ,Ceramics and Composites ,0210 nano-technology ,Faraday cage ,China ,Energy (signal processing) - Published
- 2016
33. Reactive-Atom Scattering from Liquid Crystals at the Liquid-Vacuum Interface: [C
- Author
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Simon M, Purcell, Maria A, Tesa-Serrate, Brooks C, Marshall, Duncan W, Bruce, Lucía, D'Andrea, Matthew L, Costen, John M, Slattery, Eric J, Smoll, Timothy K, Minton, and Kenneth G, McKendrick
- Abstract
Two complementary approaches were used to study the liquid-vacuum interface of the liquid-crystalline ionic liquid 1-dodecyl-3-methylimidazolium tetrafluoroborate ([C
- Published
- 2016
34. Evidence for a SN2-type pathway for phosphine exchange in phosphine-phosphenium cations, [R2P--PR'3]+
- Author
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John M. Slattery, Thomas N. Hooper, Charlotte E. Willans, Christopher A. Russell, Cheryl Fish, Michael Green, Jason M. Lynam, Dimitrios A. Pantazis, Richard J. Kilby, John C. Jeffery, and John E. McGrady more...
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Steric effects ,Stereochemistry ,Aryl ,Organic Chemistry ,General Chemistry ,Nuclear magnetic resonance spectroscopy ,Catalysis ,chemistry.chemical_compound ,Crystallography ,chemistry ,Amide ,Electrophile ,SN2 reaction ,Density functional theory ,Phosphine - Abstract
ion of a Cl(-) ion from the P-chlorophospholes, R4C4PCl (R=Me, Et), produced the P--P bonded cations [R4C4P--P(Cl)C4R4]+, which reacted with PPh3 to afford X-ray crystallographically characterised phosphine-phosphenium cations [R4C4P(PPh3)]+ (R=Me, Et). Examination of the 31P-{1H} NMR spectrum of a solution (CH2Cl(2)) of [Et4C4P-(PPh3)]+ and PPh3 revealed broadening of the resonances due to both free and coordinated PPh3, and importantly it proved possible to measure the rate of exchange between PPh3 and [Et4C4P-(PPh3)]+ by line shape analysis (gNMR programmes). The results established second-order kinetics with DeltaS( not equal)=(-106.3+/-6.7) J mol(-1) K(-1), DeltaH( not equal)=(14.9+/-1.6) kJ mol(-1) and DeltaG( not equal) (298.15 K)=(46.6+/-2.6) kJ mol(-1), values consistent with a SN2-type pathway for the exchange process. This result contrasts with the dominant dissociative (S(N)1-type) pathway reported for the analogous exchange reactions of the [ArNCH2CH2N(Ar)P(PMe3)]+ ion, and to understand in more detail the factors controlling these two different reaction pathways, we have analysed the potential energy surfaces using density functional theory (DFT). The calculations reveal that, whilst phosphine exchange in [Et4C4P(PPh3)]+ and [ArNCH2CH2N(Ar)P(PMe3)](+) is superficially similar, the two cations differ significantly in both their electronic and steric requirements. The high electrophilicity of the phosphorus center in [Et4C4P]+, combined with strong pi-pi interactions between the ring and the incoming and outgoing phenyl groups of PPh3, favours the SN2-type over the SN1-type pathway in [Et4C4P(PPh3)]+. Effective pi-donation from the amide groups reduces the intrinsic electrophilicity of [ArNCH2CH2N(Ar)P]+, which, when combined with the steric bulk of the aryl groups, shifts the mechanism in favour of a dissociative SN1-type pathway. more...
- Published
- 2016
35. Benefits to energy efficiency and environmental impact: general discussion
- Author
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Wei Xiao, John M. Slattery, Binjie Hu, Geir Martin Haarberg, Andrew Doherty, Xianbo Jin, Paul A. Madden, Hongmin Zhu, Chaohui Wei, Daniel Cooper, George Chen, Derek J. Fray, Ye Liu, Xingli Zou, Yiyang Kong, Dihua Wang, Tim Sudmeier, Shuqiang Jiao, Han Wang, Liang Xu, Ali Reza Kamali, Andrew R. Mount, Qian Xu, Majd Eshtaya, Kathie McGregor, Babak Khalaghi, Cairong Jiang, Linpo Yu, Gang Chen, Yating Yuan, Yingjun Liu, Toru H. Okabe, Olga Kuzmina, Xiangling Yue, and John T. S. Irvine more...
- Subjects
Environmental science ,Environmental impact assessment ,02 engineering and technology ,010501 environmental sciences ,Physical and Theoretical Chemistry ,Environmental economics ,021001 nanoscience & nanotechnology ,0210 nano-technology ,01 natural sciences ,0105 earth and related environmental sciences ,Efficient energy use - Published
- 2016
36. Improvements of energy conversion and storage: general discussion
- Author
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Olga Kuzmina, Dihua Wang, Paul A. Madden, Meilong Hu, John M. Slattery, George Chen, Geir Martin Haarberg, Daniel Cooper, Hongmin Zhu, Jianbang Ge, Kathie McGregor, Bencan Tang, Ye Liu, Qiushi Song, Ali Reza Kamali, Linpo Yu, John T. S. Irvine, Shuqiang Jiao, Tim Sudmeier, Xiangling Yue, Qian Xu, and Jennifer M. Pringle more...
- Subjects
business.industry ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Chemical engineering ,chemistry ,Energy transformation ,Physical and Theoretical Chemistry ,Molten salt ,0210 nano-technology ,business ,Process engineering ,Carbon ,Thermal energy - Published
- 2016
37. Liquid-Crystalline Ionic Liquids as Ordered Reaction Media for the Diels-Alder Reaction
- Author
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Yanan Gao, John M. Slattery, Duncan W. Bruce, Karina Shimizu, and José N. Canongia Lopes
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chemistry.chemical_classification ,Cyclopentadiene ,010405 organic chemistry ,Hydrogen bond ,Organic Chemistry ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,chemistry.chemical_compound ,Crystallinity ,chemistry ,Liquid crystal ,Ionic liquid ,Polymer chemistry ,Organic chemistry ,Methyl acrylate ,Alkyl ,Diels–Alder reaction - Abstract
Liquid-crystalline ionic liquids (LCILs) are ordered materials that have untapped potential to be used as reaction media for synthetic chemistry. This paper investigates the potential for the ordered structures of LCILs to influence the stereochemical outcome of the Diels–Alder reaction between cyclopentadiene and methyl acrylate. The ratio of endo- to exo-product from this reaction was monitored for a range of ionic liquids (ILs) and LCILs. Comparison of the endo:exo ratios in these reactions as a function of cation, anion and liquid crystallinity of the reaction media, allowed for the effects of liquid crystallinity to be distinguished from anion effects or cation alkyl chain length effects. These data strongly suggest that the proportion of exo-product increases as the reaction media is changed from an isotropic IL to a LCIL. A detailed molecular dynamics (MD) study suggests that this effect is related to different hydrogen bonding interactions between the reaction media and the exo- and endo-transition states in solvents with layered, smectic ordering compared to those that are isotropic. more...
- Published
- 2016
38. Charged Behaviour from Neutral Ligands: Synthesis and Properties of N-Heterocyclic Pseudo-amides
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Richard E. Douthwaite, David G. Johnson, John M. Slattery, and Robert J. Thatcher
- Subjects
chemistry.chemical_classification ,Ligand ,Stereochemistry ,Organic Chemistry ,Substituent ,Aromaticity ,General Chemistry ,Catalysis ,Coordination complex ,Crystallography ,chemistry.chemical_compound ,Deprotonation ,chemistry ,Structural isomer ,Pyridinium ,Alkyl - Abstract
Deprotonation of the 1-isopropyl-3-(phenylamino)pyridin-1-ium iodide gives the corresponding neutral betaine, which is formalised as a pyridinium-amido ligand when coordinated to a metal. Spectroscopic, structural and theoretical methods have been used to investigate the metal-ligand bonding, ligand dynamics and electron distribution. Collectively, the data show that the ligand can be characterised as a pseudo-amide and is a strong donor akin to alkyl phosphines and N-heterocyclic carbenes. Furthermore, rotation about both N substituent C-N bonds occurs, which is in contrast to the two alternative pyridinium positional isomers that exhibit neutral resonance structures. For comparison, compounds and complexes derived from norharman were prepared, which contain an additional C-C bond supporting conjugation and the accessibility of a neutral resonance structure. Notwithstanding the formal neutral structure, norharman-derived ligands are comparably strong donors, and have the additional advantage of exhibiting stability to dioxygen and water. more...
- Published
- 2012
- Full Text
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39. How Lewis acidic is your cation? Putting phosphenium ions on the fluoride ion affinity scale
- Author
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John M. Slattery and Sharifa Hussein
- Subjects
Inorganic Chemistry ,Steric effects ,chemistry.chemical_compound ,Chemistry ,Electrophile ,Inorganic chemistry ,Substituent ,Lewis acids and bases ,Ab inito ,Medicinal chemistry ,Fluoride ,Affinities ,Ion - Abstract
The fluoride ion affinities (FIAs) of 33 phosphenium ions with a range of substituents were calculated using ab inito and DFT methods. The use of these FIA data as a measure of the Lewis acidities of phosphenium ions is described and the FIAs of the species studied here are compared to FIA data for more commonly encountered Lewis acids. Phosphenium ions are often stronger Lewis acids than neutral species, but in many cases are less Lewis acidic than highly electrophilic cations such as [Me(3)C](+) or [Me(3)Si](+). The impact of mesomeric, inductive and steric substituent effects on FIAs are discussed and related to the underlying electronic structures of different cation types. A comparison between the FIAs of known "free" phosphenium ions with those that are currently unknown and other highly electrophilic cations suggests that some diaryl- and dialkylphosphenium ions may yet be accessible under the right conditions. more...
- Published
- 2012
- Full Text
- View/download PDF
40. Comparison of donor properties of N-heterocyclic carbenes and N-donors containing the 1H-pyridin-(2E)-ylidene motif
- Author
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Richard E. Douthwaite, John M. Slattery, Qi Shi, and Robert J. Thatcher
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Ligand ,Stereochemistry ,General Chemical Engineering ,chemistry.chemical_element ,General Chemistry ,Rhodium ,Electronegativity ,Crystallography ,chemistry.chemical_compound ,chemistry ,Electrophile ,Molecular orbital ,HOMO/LUMO ,Carbene ,Palladium - Abstract
IR spectroscopic and X-ray structural data of rhodium and palladium complexes of N-heterocyclic carbene (NHC) and 1H-pyridin-(2E)-ylidene (PYE) ligands indicate that both ligand classes exhibit similar electron-donating properties. However, catalytic application of palladium PYE complexes appears to be limited by PYE ligand loss. Density functional theory (DFT) calculations show that the Pd–CNHC σ-bond is very low-lying in energy (HOMO-14 and 15, ca. –11 eV) and a π-backbonding contribution is also present, whereas the Pd-NPYE σ-bond is comparatively high-lying (HOMO-9 and 10, ca. –8 eV) and the highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) gap is also significantly less (4.0 vs. 5.6 eV). Essentially, electronegativity differences between Pd, C, and N render the Pd–N bond much more polarized and susceptible to electrophilic and nucleophilic attack and hence ligand substitution. more...
- Published
- 2010
- Full Text
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41. Ein einfacher Zugang zu einwertigen Gallium-Salzen mit schwach koordinierenden Anionen
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Alexander Higelin, John M. Slattery, Thomas Bayer, and Ingo Krossing
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Materials science ,General Medicine - Published
- 2010
- Full Text
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42. O(3P) Atoms as a Chemical Probe of Surface Ordering in Ionic Liquids
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Kenneth G. McKendrick, John M. Slattery, Carla Waring, Paul A. J. Bagot, and Matthew L. Costen
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chemistry.chemical_classification ,Surface (mathematics) ,Radical ,Fluorescence ,chemistry.chemical_compound ,chemistry ,Ionic liquid ,Organic chemistry ,Physical chemistry ,Reactivity (chemistry) ,Physical and Theoretical Chemistry ,Imide ,Alkyl ,Stoichiometry - Abstract
The reactivity of photolytically generated, gas-phase, ground-state atomic oxygen, O(3P), with the surfaces of a series of 1-alkyl-3- methylimidazolium bis(trifluoromethylsulfonyl)imide ([NTf2]) ionic liquids has been investigated. The liquids differ only in the length of the linear CnH2n+1 alkyl side chain on the cation, with n = 2, 4, 5, 8, and 12. Laser-induced fluorescence was used to detect gas-phase OH v′ = 0 radicals formed at the gas-liquid interface. The reactivity of the ionic liquids increases nonlinearly with n, in a way that cannot simply be explained by stoichiometry. We infer that the alkyl chains must be preferentially exposed at the interface to a degree that is dependent on chain length. A relatively sharp onset of surface segregation is apparent in the region of n = 4. The surface specificity of the method is confirmed through the nonthermal characteristics of both the translational and rotational distributions of the OH v′ = 0. These reveal that the dynamics are dominated by a direct, impulsive scattering mechanism at the outer layers of the liquid. The OH v′ = 0 yield is effectively independent of the bulk temperature of the longest-chain ionic liquid in the range 298-343 K, also consistent with a predominantly direct mechanism. These product attributes are broadly similar to those of the benchmark pure hydrocarbon liquid, squalane, but a more detailed analysis suggests that the interface may be microscopically smoother for the ionic liquids. © 2010 American Chemical Society. more...
- Published
- 2010
- Full Text
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43. Scattering Dynamics of Hyperthermal Oxygen Atoms on Ionic Liquid Surfaces: [emim][NTf2] and [C12mim][NTf2]
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Scott Yockel, John M. Slattery, Timothy K. Minton, Kenneth G. McKendrick, George C. Schatz, Jianming Zhang, and Bohan Wu
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chemistry.chemical_classification ,Scattering ,Analytical chemistry ,Mass spectrometry ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,General Energy ,Oxygen atom ,chemistry ,Thermal ,Ionic liquid ,Translational energy ,Physical and Theoretical Chemistry ,Imide ,Alkyl - Abstract
Collisions of hyperthermal oxygen atoms, with an average laboratory-frame translational energy of 520 kJ mol−1, on continuously refreshed ionic liquids, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([emim][NTf2]) and 1-dodecyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([C12mim][NTf2]), were studied with the use of a beam-surface scattering technique. Time-of-flight and angular distributions of inelastically scattered O and reactively scattered OH and H2O were collected for various angles of incidence with the use of a rotatable mass spectrometer detector. For both O and OH, two distinct scattering processes were identified, which can be empirically categorized as thermal and nonthermal. Nonthermal scattering is more probable for both O and OH products. The observation of OH confirms that at least some reactive sites, presumably alkyl groups, must be exposed at the surface. The ionic liquid with the longer alkyl chain, [C12mim][NTf2], is substantially more reactive than the l... more...
- Published
- 2010
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44. Cooperative Effect of a Classical and a Weak Hydrogen Bond for the Metal-Induced Construction of a Self-Assembled β-Turn Mimic
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John M. Slattery, Andy Ch. Laungani, Ingo Krossing, Bernhard Breit, and Manfred Keller
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chemistry.chemical_classification ,Mechanical bond ,Chemistry ,Stereochemistry ,Hydrogen bond ,Organic Chemistry ,Low-barrier hydrogen bond ,Supramolecular chemistry ,General Chemistry ,Catalysis ,Supramolecular polymers ,Crystallography ,Molecular recognition ,Chemical bond ,Non-covalent interactions - Abstract
A novel metal-induced template for the self-assembly of two independent phosphane ligands by means of unprecedented multiple noncovalent interactions (classical hydrogen bond, weak hydrogen bond, metal coordination, pi-stacking interaction) was developed and investigated. Our results address the importance and capability of weak hydrogen bonds (WHBs) as important attractive interactions in self-assembling processes based on molecular recognition. Together with a classical hydrogen bond, WHBs may serve as promoters for the specific self-assembly of complementary monomeric phosphane ligands into supramolecular hybrid structures. The formation of an intermolecular C-H...N hydrogen bond and its persistence in the solid state and in solution was studied by X-ray crystal analysis, mass spectrometry and NMR spectroscopy analysis. Further evidence was demonstrated by DFT calculations, which gave specific geometric parameters for the proposed conformations and allowed us to estimate the energy involved in the hydrogen bonds that are responsible for the molecular recognition process. The presented template can be regarded as a new type of self-assembled beta-turn mimic or supramolecular pseudo amino acid for the nucleation of beta-sheet structures when attached to oligopeptides. more...
- Published
- 2009
- Full Text
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45. In Silico Prediction of Molecular Volumes, Heat Capacities, and Temperature-Dependent Densities of Ionic Liquids
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Ulrich P. Preiss, Ingo Krossing, and John M. Slattery
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Lattice energy ,chemistry.chemical_compound ,chemistry ,Volume (thermodynamics) ,General Chemical Engineering ,In silico ,Ionic liquid ,Thermodynamics ,General Chemistry ,Heat capacity ,Industrial and Manufacturing Engineering - Abstract
We present a fast and reliable general estimation of the heat capacity, Cp, and temperature-dependent density, ρ, of ionic liquids, based on a new in silico method to calculate the molecular volume, Vm. The knowledge of Vm allows the prediction of many physical properties of hitherto unknown ionic liquids as well as the prediction of lattice energies and entropies of salts. more...
- Published
- 2009
- Full Text
- View/download PDF
46. Ein leichter Zugang zur nicht-oxidierenden Lewis-Supersäure PhF→Al(ORF)3(RF=C(CF3)3)
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Gustavo Santiso-Quiñones, Lutz O. Müller, Ingo Krossing, Volker Brecht, Daniel Himmel, John M. Slattery, Gunther Steinfeld, and Julia Stauffer
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Chemistry ,General Medicine - Published
- 2008
- Full Text
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47. Supramolecular Bidentate Ligands by Metal-Directed in situ Formation of Antiparallel β-Sheet Structures and Application in Asymmetric Catalysis
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John M. Slattery, Ingo Krossing, Bernhard Breit, and Andy Ch. Laungani
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Models, Molecular ,Macromolecular Substances ,Molecular Conformation ,Supramolecular chemistry ,Beta sheet ,Crystallography, X-Ray ,Ligands ,Antiparallel (biochemistry) ,Protein Structure, Secondary ,Catalysis ,Supramolecular assembly ,Molecular recognition ,Organometallic Compounds ,Transition Elements ,Combinatorial Chemistry Techniques ,Rhodium ,Carbon Monoxide ,Chemistry ,Organic Chemistry ,Enantioselective synthesis ,Hydrogen Bonding ,General Chemistry ,Combinatorial chemistry ,Models, Chemical ,Peptides ,Supramolecular catalysis ,Hydrogen - Abstract
The principles of protein structure design, molecular recognition, and supramolecular and combinatorial chemistry have been applied to develop a convergent metal-ion-assisted self-assembly approach that is a very simple and effective method for the de novo design and the construction of topologically predetermined antiparallel beta-sheet structures and self-assembled catalysts. A new concept of in situ generation of bidentate P-ligands for transition-metal catalysis, in which two complementary, monodentate, peptide-based ligands are brought together by employing peptide secondary structure motif as constructing tool to direct the self-assembly process, is achieved through formation of stable beta-sheet motifs and subsequent control of selectivity. The supramolecular structures were studied by (1)H, (31)P, and (13)C NMR spectroscopy, ESI mass spectrometry, X-ray structure analysis, and theoretical calculations. Our initial catalysis results confirm the close relationship between the self-assembled sheet conformations and the catalytic activity of these metallopeptides in the asymmetric rhodium-catalyzed hydroformylation. Good catalyst activity and moderate enantioselectivity were observed for the selected combination of catalyst and substrate, but most importantly the concept of this new methodology was successfully proven. This work presents a perspective interface between protein design and supramolecular catalysis for the design of beta-sheet mimetics and screening of libraries of self-organizing supramolecular catalysts. more...
- Published
- 2008
- Full Text
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48. Supercritical CO2 extraction as an effective pretreatment step for wax extraction in a miscanthus biorefinery
- Author
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Simon J. McQueen-Mason, Thomas M. Attard, Oene Dolstra, John M. Slattery, Claire Lessa Alvim Kamei, Andrew J. Hunt, C. Robert McElroy, Richard Gammons, Luisa M. Trindade, Seishi Shimizu, Nontipa Supanchaiyamat, and Neil C. Bruce more...
- Subjects
General Chemical Engineering ,Biomass ,Miscanthus sinensis ,Extraction ,Miscanthus ,010402 general chemistry ,Saccharification ,01 natural sciences ,Laboratorium voor Plantenveredeling ,Botany ,Supercritical ,Environmental Chemistry ,Wax ,PBR Biobased Economy ,Chromatography ,Supercritical carbon dioxide ,biology ,010405 organic chemistry ,Renewable Energy, Sustainability and the Environment ,Chemistry ,Extraction (chemistry) ,General Chemistry ,biology.organism_classification ,Biorefinery ,Supercritical fluid ,0104 chemical sciences ,Plant Breeding ,Carbon dioxide ,13. Climate action ,visual_art ,PBR Bio-based Economy ,Waxes ,visual_art.visual_art_medium ,EPS - Abstract
The use of supercritical carbon dioxide (scCO2) to extract valuable lipophilic compounds from miscanthus was investigated and subsequent enzymatic saccharification was carried out to determine the impact of scCO2 extraction on downstream processing of miscanthus. Two miscanthus genotypes (Miscanthus x. giganteus and Miscanthus sinensis) were investigated and characterized. A diverse range of molecules were detected including long-chain hydrocarbons, fatty acids, n-policosanols, aldehydes, wax esters, sterols and steroid ketones. Quantification data indicates that there is a considerable difference among each species in the quantities of specific compounds. The waxes also exhibited significant differences in melting temperature, thus illustrating the opportunity for utilization in various applications. In addition to the isolation of valuable chemical compounds, the scCO2 pretreatment also had a beneficial effect on the downstream processing of the biomass. The total sugars released after saccharification was found to increase by around 20% when coupled with scCO2 extraction, as compared to untreated samples. more...
- Published
- 2016
49. How to Predict the Physical Properties of Ionic Liquids: A Volume-Based Approach
- Author
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John M. Slattery, Corinne Daguenet, Paul J. Dyson, Thomas J. S. Schubert, and Ingo Krossing
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General Medicine - Published
- 2007
- Full Text
- View/download PDF
50. Access to novel fluorovinylidene ligands via exploitation of outer-sphere electrophilic fluorination: new insights into C-F bond formation and activation
- Author
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John M. Slattery, Natalie E. Pridmore, Lucy M. Milner, Adrian C. Whitwood, Matthew K. Skeats, Lewis M. Hall, and Jason M. Lynam
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010405 organic chemistry ,Ligand ,Stereochemistry ,Electrophilic fluorination ,chemistry.chemical_element ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,0104 chemical sciences ,Ruthenium ,Inorganic Chemistry ,chemistry.chemical_compound ,Nucleophile ,chemistry ,Pyridine ,Reactivity (chemistry) ,Pyridinium ,Bond cleavage - Abstract
Metal vinylidene complexes are widely encountered, or postulated, as intermediates in a range of important metal-mediated transformations of alkynes. However, fluorovinylidene complexes have rarely been described and their reactivity is largely unexplored. By making use of the novel outer-sphere electrophilic fluorination (OSEF) strategy we have developed a rapid, robust and convenient method for the preparation of fluorovinylidene and trifluoromethylvinylidene ruthenium complexes from non-fluorinated alkynes. Spectroscopic investigations (NMR and UV/Vis), coupled with TD-DFT studies, show that fluorine incorporation results in significant changes to the electronic structure of the vinylidene ligand. The reactivity of fluorovinylidene complexes shows many similarities to non-fluorinated analogues, but also some interesting differences, including a propensity to undergo unexpected C-F bond cleavage reactions. Heating fluorovinylidene complex [Ru(η(5)-C5H5)(PPh3)2(C[double bond, length as m-dash]C{F}R)][BF4] led to C-H activation of a PPh3 ligand to form an orthometallated fluorovinylphosphonium ligand. Reaction with pyridine led to nucleophilic attack at the metal-bound carbon atom of the vinylidene to form a vinyl pyridinium species, which undergoes both C-H and C-F activation to give a novel pyridylidene complex. Addition of water, in the presence of chloride, leads to anti-Markovnikov hydration of a fluorovinylidene complex to form an α-fluoroaldehyde, which slowly rearranges to its acyl fluoride isomer. Therefore, fluorovinylidenes ligands may be viewed as synthetic equivalents of 1-fluoroalkynes providing access to reactivity not possible by other routes. more...
- Published
- 2015
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