1
|
Stankiewicz A, Kasparek A, Masiewicz E, Kruk D. Diffusion of Water Molecules on the Surface of Silica Nanoparticles─Insights from Nuclear Magnetic Resonance Relaxometry. J Phys Chem B 2024; 128:1535-1543. [PMID: 38295281 PMCID: PMC10875636 DOI: 10.1021/acs.jpcb.3c06451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 12/15/2023] [Accepted: 12/15/2023] [Indexed: 02/02/2024]
Abstract
1H spin-lattice nuclear magnetic resonance (NMR) relaxation experiments have been performed for water dispersions of functionalized silica nanoparticles of diameters of 25 and 45 nm. The experiments have been performed in a broad frequency range spanning 3 orders of magnitude, from 10 kHz to 10 MHz, versus temperature, from 313 to 263 K. On the basis of the data, two-dimensional translation diffusion (diffusion close to the nanoparticle surface within a layer of the order of a few diameters of water molecules) has been revealed. The translational correlation times as well as the residence life times on the nanoparticle surface have been determined. It has turned out that the residence lifetime is temperature-independent and is on the order of 5 × 10-6 s for the smaller nanoparticles and by about a factor of 3 longer for the larger ones. The translational correlation time for the case of 25 nm nanoparticles is also temperature-independent and yields about 6 × 10-7 s, while for the dispersion of the larger nanoparticles, the correlation times changed from about 8 × 10-7 s at 313 K to about 1.2 × 10-6 s at 263 K. In addition to the quantitative characterization of the two-dimensional translation diffusion, correlation times associated with bound water molecules have been determined. The studies have also given insights into the population of the bound and diffusing water on the surface water fractions.
Collapse
Affiliation(s)
- Aleksandra Stankiewicz
- Department of Physics and
Biophysics, University of Warmia & Mazury
in Olsztyn, Oczapowskiego 4, 10-719 Olsztyn, Poland
| | - Adam Kasparek
- Department of Physics and
Biophysics, University of Warmia & Mazury
in Olsztyn, Oczapowskiego 4, 10-719 Olsztyn, Poland
| | - Elzbieta Masiewicz
- Department of Physics and
Biophysics, University of Warmia & Mazury
in Olsztyn, Oczapowskiego 4, 10-719 Olsztyn, Poland
| | - Danuta Kruk
- Department of Physics and
Biophysics, University of Warmia & Mazury
in Olsztyn, Oczapowskiego 4, 10-719 Olsztyn, Poland
| |
Collapse
|
2
|
Fraenza CC, Greenbaum SG, Suarez SN. Nuclear Magnetic Resonance Relaxation Pathways in Electrolytes for Energy Storage. Int J Mol Sci 2023; 24:10373. [PMID: 37373520 DOI: 10.3390/ijms241210373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 06/15/2023] [Accepted: 06/16/2023] [Indexed: 06/29/2023] Open
Abstract
Nuclear Magnetic Resonance (NMR) spin relaxation times have been an instrumental tool in deciphering the local environment of ionic species, the various interactions they engender and the effect of these interactions on their dynamics in conducting media. Of particular importance has been their application in studying the wide range of electrolytes for energy storage, on which this review is based. Here we highlight some of the research carried out on electrolytes in recent years using NMR relaxometry techniques. Specifically, we highlight studies on liquid electrolytes, such as ionic liquids and organic solvents; on semi-solid-state electrolytes, such as ionogels and polymer gels; and on solid electrolytes such as glasses, glass ceramics and polymers. Although this review focuses on a small selection of materials, we believe they demonstrate the breadth of application and the invaluable nature of NMR relaxometry.
Collapse
Affiliation(s)
- Carla C Fraenza
- Physics Department, Hunter College, City University of New York, 695 Park Avenue, New York, NY 10065, USA
| | - Steve G Greenbaum
- Physics Department, Hunter College, City University of New York, 695 Park Avenue, New York, NY 10065, USA
- Physics Department, The Graduate Center, City University of New York, 365 Fifth Avenue, New York, NY 10016, USA
| | - Sophia N Suarez
- Physics Department, The Graduate Center, City University of New York, 365 Fifth Avenue, New York, NY 10016, USA
- Physics Department, Brooklyn College, City University of New York, 2900 Bedford Avenue, Brooklyn, NY 11210, USA
| |
Collapse
|
3
|
Water Dynamics in Highly Concentrated Protein Systems-Insight from Nuclear Magnetic Resonance Relaxometry. Int J Mol Sci 2023; 24:ijms24044093. [PMID: 36835511 PMCID: PMC9963861 DOI: 10.3390/ijms24044093] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/07/2023] [Accepted: 02/10/2023] [Indexed: 02/22/2023] Open
Abstract
1H spin-lattice relaxation experiments have been performed for water-Bovine Serum Albumin (BSA) mixtures, including 20%wt and 40%wt of BSA. The experiments have been carried out in a frequency range encompassing three orders of magnitude, from 10 kHz to 10 MHz, versus temperature. The relaxation data have been thoroughly analyzed in terms of several relaxation models with the purpose of revealing the mechanisms of water motion. For this purpose, four relaxation models have been used: the data have been decomposed into relaxation contributions expressed in terms of Lorentzian spectral densities, then three-dimensional translation diffusion has been assumed, next two-dimensional surface diffusion has been considered, and eventually, a model of surface diffusion mediated by acts of adsorption to the surface has been employed. In this way, it has been demonstrated that the last concept is the most plausible. Parameters describing the dynamics in a quantitative manner have been determined and discussed.
Collapse
|
4
|
Kruk D, Masiewicz E, Kołodziejski K, Markiewicz R, Jurga S. Relative Cation-Anion Diffusion in Alkyltriethylammonium-Based Ionic Liquids. Int J Mol Sci 2022; 23:ijms23115994. [PMID: 35682674 PMCID: PMC9181216 DOI: 10.3390/ijms23115994] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 05/11/2022] [Accepted: 05/14/2022] [Indexed: 02/04/2023] Open
Abstract
19F Nuclear Magnetic Resonance spin-lattice relaxation experiments have been performed for a series of ionic liquids including the same anion, bis(trifluoromethanesulfonyl)imide, and cations with alkyl chains of different lengths: triethylhexylammonium, triethyloctylammonium, decyltriethylammonium, dodecyltriethylammonium, decyltriethylammonium, and hexadecyltriethylammonium. The experiments have been carried out in a frequency range of 10 kHz to 10 MHz versus temperature. A thorough analysis of the relaxation data has led to the determination of the cation–anion as a relative translation diffusion coefficient. The diffusion coefficients have been compared with the corresponding cation–cation and anion–anion diffusion coefficients, revealing a correlation in the relative translation movement of the anion and the triethylhexylammonium, triethyloctylammonium, decyltriethylammonium, and dodecyltriethylammonium cations, whereas the relative translation diffusion between the anion and the cations with the longer alkyl chains, decyltriethylammonium and hexadecyltriethylammonium, remains rather uncorrelated (correlated to a much lesser extent).
Collapse
Affiliation(s)
- Danuta Kruk
- Department of Physics and Biophysics, University of Warmia & Mazury in Olsztyn, Oczapowskiego 4, 10-719 Olsztyn, Poland; (E.M.); (K.K.)
- Correspondence:
| | - Elżbieta Masiewicz
- Department of Physics and Biophysics, University of Warmia & Mazury in Olsztyn, Oczapowskiego 4, 10-719 Olsztyn, Poland; (E.M.); (K.K.)
| | - Karol Kołodziejski
- Department of Physics and Biophysics, University of Warmia & Mazury in Olsztyn, Oczapowskiego 4, 10-719 Olsztyn, Poland; (E.M.); (K.K.)
| | - Roksana Markiewicz
- NanoBioMedical Centre, Adam Mickiewicz University, Wszechnicy Piastowskiej 3, 61-614 Poznan, Poland; (R.M.); (S.J.)
| | - Stefan Jurga
- NanoBioMedical Centre, Adam Mickiewicz University, Wszechnicy Piastowskiej 3, 61-614 Poznan, Poland; (R.M.); (S.J.)
| |
Collapse
|
5
|
Damodaran K. Recent advances in NMR spectroscopy of ionic liquids. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2022; 129:1-27. [PMID: 35292132 DOI: 10.1016/j.pnmrs.2021.12.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 12/17/2021] [Accepted: 12/28/2021] [Indexed: 06/14/2023]
Abstract
This review presents recent developments in the application of NMR spectroscopic techniques in the study of ionic liquids. NMR has been the primary tool not only for the structural characterization of ionic liquids, but also for the study of dynamics. The presence of a host of NMR active nuclei in ionic liquids permits widespread use of multinuclear NMR experiments. Chemical shifts and multinuclear coupling constants are used routinely for the structure elucidation of ionic liquids and of products formed by their covalent interactions with other materials. Also, the availability of a multitude of NMR techniques has facilitated the study of dynamical processes in them. These include the use of NOESY to study inter-ionic interactions, pulsed-field gradient techniques for probing transport properties, and relaxation measurements to elucidate rotational dynamics. This review will focus on the application of each of these techniques to investigate ionic liquids.
Collapse
Affiliation(s)
- Krishnan Damodaran
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, United States.
| |
Collapse
|
6
|
Kruk D, Masiewicz E, Budny J, Stankiewicz A, Lotarska S, Oztop M, Wieczorek Z. Diffusion in oils versus their viscosity – Insight from Nuclear Magnetic Resonance relaxometry. J FOOD ENG 2022. [DOI: 10.1016/j.jfoodeng.2021.110848] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
7
|
Kruk D, Masiewicz E, Budny J, Kolodziejski K, Zulewska J, Wieczorek Z. Relationship between macroscopic properties of honey and molecular dynamics – temperature effects. J FOOD ENG 2022. [DOI: 10.1016/j.jfoodeng.2021.110782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
8
|
Relationship between Translational and Rotational Dynamics of Alkyltriethylammonium-Based Ionic Liquids. Int J Mol Sci 2022; 23:ijms23031688. [PMID: 35163609 PMCID: PMC8836145 DOI: 10.3390/ijms23031688] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 01/22/2022] [Accepted: 01/26/2022] [Indexed: 02/05/2023] Open
Abstract
1H spin-lattice relaxation experiments have been performed for a series of ionic liquids including bis(trifluoromethanesulfonyl)imide anion and cations of a varying alkyl chain length: triethylhexylammonium, triethyloctylammonium, decyltriethylammonium, dodecyltriethylammonium, triethyltetradecylammonium, and hexadecyltriethylammonium. The relaxation studies were carried out in abroad frequency range covering three orders of magnitude, from 10 kHz to 10 MHz, versus temperature. On the basis of a thorough, quantitative analysis of this reach data set, parameters characterizing the relative, cation-cation, translation diffusion (relative diffusion coefficients and translational correlation times), and rotational motion of the cation (rotational correlation times) were determined. Relationships between these quantities and their dependence on the alkyl chain length were discussed in comparison to analogous properties of molecular liquids. It was shown, among other findings, that the ratio between the translational and rotational correlation times is smaller than for molecular liquids and considerably dependent on temperature. Moreover, a comparison of relative and self-diffusion coefficients indicate correlated translational dynamics of the cations.
Collapse
|
9
|
Fraenza CC, Elgammal RA, Garaga MN, Bhattacharyya S, Zawodzinski TA, Greenbaum SG. Dynamics of Glyceline and Interactions of Constituents: A Multitechnique NMR Study. J Phys Chem B 2022; 126:890-905. [DOI: 10.1021/acs.jpcb.1c09227] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Carla C. Fraenza
- Department of Physics and Astronomy, Hunter College of CUNY, New York, New York 10065, United States
| | - Ramez A. Elgammal
- Department of Chemical and Biomolecular Engineering, University of Tennessee-Knoxville, Knoxville, Tennessee 37996, United States
| | - Mounesha N. Garaga
- Department of Physics and Astronomy, Hunter College of CUNY, New York, New York 10065, United States
| | - Sahana Bhattacharyya
- Department of Physics and Astronomy, Hunter College of CUNY, New York, New York 10065, United States
| | - Thomas A. Zawodzinski
- Department of Chemical and Biomolecular Engineering, University of Tennessee-Knoxville, Knoxville, Tennessee 37996, United States
| | - Steven G. Greenbaum
- Department of Physics and Astronomy, Hunter College of CUNY, New York, New York 10065, United States
| |
Collapse
|
10
|
Kruk D, Jancelewicz M, Klimaszyk A, Markiewicz R, Fojud Z, Jurga S. Internal Dynamics of Ionic Liquids over a Broad Temperature Range-The Role of the Cation Structure. MATERIALS (BASEL, SWITZERLAND) 2021; 15:ma15010216. [PMID: 35009361 PMCID: PMC8746224 DOI: 10.3390/ma15010216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 12/21/2021] [Accepted: 12/21/2021] [Indexed: 05/08/2023]
Abstract
1H and 19F spin-lattice relaxation experiments have been performed for a series of ionic liquids sharing the same anion: bis(trifluoromethanesulfonyl)imide but including cations of different alkyl chain lengths: butyltriethylammonium, triethyloctylammonium, dodecyltriethylammo-nium and hexadecyltriethylammonium. The studies have been carried out in the temperature range from 383 to 108 K at the resonance frequency of 200 MHz (for 1H). A quantitative analysis of the relaxation data has revealed two dynamical processes for both kinds of ions. The dynamics have been successfully modeled in terms of the Arrhenius law. The timescales of the dynamical processes and their temperature evolution have been discussed in detail, depending on the structure of the cation.
Collapse
Affiliation(s)
- Danuta Kruk
- Department of Physics and Biophysics, University of Warmia & Mazury in Olsztyn, Oczapowskiego 4, 10-719 Olsztyn, Poland
- NanoBioMedical Centre, Adam Mickiewicz University, Wszechnicy Piastowskiej 3, 61-614 Poznan, Poland; (M.J.); (A.K.); (R.M.); (S.J.)
- Correspondence:
| | - Mariusz Jancelewicz
- NanoBioMedical Centre, Adam Mickiewicz University, Wszechnicy Piastowskiej 3, 61-614 Poznan, Poland; (M.J.); (A.K.); (R.M.); (S.J.)
| | - Adam Klimaszyk
- NanoBioMedical Centre, Adam Mickiewicz University, Wszechnicy Piastowskiej 3, 61-614 Poznan, Poland; (M.J.); (A.K.); (R.M.); (S.J.)
| | - Roksana Markiewicz
- NanoBioMedical Centre, Adam Mickiewicz University, Wszechnicy Piastowskiej 3, 61-614 Poznan, Poland; (M.J.); (A.K.); (R.M.); (S.J.)
| | - Zbigniew Fojud
- Department of MacromoLecular Physics, Faculty of Physics, Adam Mickiewicz University, Uniwersytetu Poznanskiego 2, 61-614 Poznan, Poland;
| | - Stefan Jurga
- NanoBioMedical Centre, Adam Mickiewicz University, Wszechnicy Piastowskiej 3, 61-614 Poznan, Poland; (M.J.); (A.K.); (R.M.); (S.J.)
| |
Collapse
|
11
|
Kruk D, Masiewicz E, Lotarska S, Markiewicz R, Jurga S. Correlated Dynamics in Ionic Liquids by Means of NMR Relaxometry: Butyltriethylammonium bis(Trifluoromethanesulfonyl)imide as an Example. Int J Mol Sci 2021; 22:ijms22179117. [PMID: 34502026 PMCID: PMC8431572 DOI: 10.3390/ijms22179117] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/13/2021] [Accepted: 08/16/2021] [Indexed: 11/27/2022] Open
Abstract
1H and 19F spin-lattice relaxation experiments have been performed for butyltriethylammonium bis(trifluoromethanesulfonyl)imide in the temperature range from 258 to 298 K and the frequency range from 10 kHz to 10 MHz. The results have thoroughly been analysed in terms of a relaxation model taking into account relaxation pathways associated with 1H–1H, 19F–19F and 1H–19F dipole–dipole interactions, rendering relative translational diffusion coefficients for the pairs of ions: cation–cation, anion–anion and cation–anion, as well as the rotational correlation time of the cation. The relevance of the 1H–19F relaxation contribution to the 1H and 19F relaxation has been demonstrated. A comparison of the diffusion coefficients has revealed correlation effects in the relative cation–anion translational movement. It has also turned out that the translational movement of the anions is faster than of cations, especially at high temperatures. Moreover, the relative cation–cation diffusion coefficients have been compared with self-diffusion coefficients obtained by means of NMR (Nuclear Magnetic Resonance) gradient diffusometry. The comparison indicates correlation effects in the relative cation–cation translational dynamics—the effects become more pronounced with decreasing temperature.
Collapse
Affiliation(s)
- Danuta Kruk
- Department of Physics and Biophysics, University of Warmia and Mazury in Olsztyn, Oczapowskiego 4, 10-719 Olsztyn, Poland; (E.M.); (S.L.)
- NanoBioMedical Centre, Adam Mickiewicz University, Wszechnicy Piastowskiej 3, 61-614 Poznan, Poland; (R.M.); (S.J.)
- Correspondence:
| | - Elzbieta Masiewicz
- Department of Physics and Biophysics, University of Warmia and Mazury in Olsztyn, Oczapowskiego 4, 10-719 Olsztyn, Poland; (E.M.); (S.L.)
| | - Sylwia Lotarska
- Department of Physics and Biophysics, University of Warmia and Mazury in Olsztyn, Oczapowskiego 4, 10-719 Olsztyn, Poland; (E.M.); (S.L.)
| | - Roksana Markiewicz
- NanoBioMedical Centre, Adam Mickiewicz University, Wszechnicy Piastowskiej 3, 61-614 Poznan, Poland; (R.M.); (S.J.)
| | - Stefan Jurga
- NanoBioMedical Centre, Adam Mickiewicz University, Wszechnicy Piastowskiej 3, 61-614 Poznan, Poland; (R.M.); (S.J.)
| |
Collapse
|
12
|
Kruk D, Florek-Wojciechowska M, Oztop M, Ilhan E, Wieczorek Z. Water dynamics in eggs by means of Nuclear Magnetic Resonance relaxometry. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2021; 327:106976. [PMID: 33901897 DOI: 10.1016/j.jmr.2021.106976] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 03/28/2021] [Accepted: 03/29/2021] [Indexed: 06/12/2023]
Abstract
1H Nuclear Magnetic Resonance relaxometry has been applied to reveal dynamical properties of water molecules embedded into egg yolk and white of three species: turkey, chicken and quail. Two fractions of water molecules, referred to as confined-water and free-water fractions, have been revealed. It has been demonstrated that translation diffusion of the confined-water fraction is three-dimensional. The dynamics of the confined-water has been quantitatively described in terms of diffusion coefficients and rotational correlation times. The parameters have been compared for egg yolk and white for all the species. In addition to these quantities, the number of the confined-water molecules per unit volume has been provided for all cases. The obtained parameters provide insight into the dynamics of water in eggs of different origin and allow to identify similarities and differences between them in connection to the structure of the network formed by the macromolecular fraction of egg yolk and white.
Collapse
Affiliation(s)
- Danuta Kruk
- Department of Physics & Biophysics, Faculty of Food Sciences, University of Warmia & Mazury in Olsztyn, Michała Oczapowskiego 4, 10-719 Olsztyn, Poland.
| | - Małgorzata Florek-Wojciechowska
- Department of Physics & Biophysics, Faculty of Food Sciences, University of Warmia & Mazury in Olsztyn, Michała Oczapowskiego 4, 10-719 Olsztyn, Poland
| | - Mecit Oztop
- Department of Food Engineering, Middle East Technical University, Ankara, Turkey
| | - Esmanur Ilhan
- Department of Food Engineering, Middle East Technical University, Ankara, Turkey
| | - Zbigniew Wieczorek
- Department of Physics & Biophysics, Faculty of Food Sciences, University of Warmia & Mazury in Olsztyn, Michała Oczapowskiego 4, 10-719 Olsztyn, Poland
| |
Collapse
|
13
|
Kruk D, Florek – Wojciechowska M, Masiewicz E, Oztop M, Ploch-Jankowska A, Duda P, Wilczynski S. Water mobility in cheese by means of Nuclear Magnetic Resonance relaxometry. J FOOD ENG 2021. [DOI: 10.1016/j.jfoodeng.2021.110483] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
|
14
|
Molecular-level insights into structure and dynamics in ionic liquids and polymer gel electrolytes. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.115454] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
15
|
Overbeck V, Appelhagen A, Rößler R, Niemann T, Ludwig R. Rotational correlation times, diffusion coefficients and quadrupolar peaks of the protic ionic liquid ethylammonium nitrate by means of 1H fast field cycling NMR relaxometry. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.114983] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
16
|
Overbeck V, Schröder H, Bonsa AM, Neymeyr K, Ludwig R. Insights into the translational and rotational dynamics of cations and anions in protic ionic liquids by means of NMR fast-field-cycling relaxometry. Phys Chem Chem Phys 2021; 23:2663-2675. [PMID: 33480888 DOI: 10.1039/d0cp05440b] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Understanding the translational and rotational dynamics of cations and anions in hydrogen bonded protic ionic liquids (PIls) is still a challenge. In this study, we determine self-diffusion coefficients and rotational correlation times of both ions in triethylammonium based PILs by means of NMR Fast-Field-Cycling (FFC) relaxometry. Global fits of 1H and 19F nuclear magnetic relaxation dispersion (NMRD) curves allowed proper separation into intra and inter molecular relaxation rates for both NMR sensitive nuclei and thus a reliable description of translational and rotational motion for both ions individually. The diffusion coefficients of the cations are in the order of 6 × 10-11 m2 s-1 at room temperature and about 50 per cent larger than those of the anions. The diffusion coefficients of cations and anions in both PILs were compared with those we derived from applying an universal dispersion power law and those known from pulsed field gradient (PFG) NMR studies. Considering the Nernst-Einstein equation, molar conductivities were calculated from cationic and anionic diffusion coefficients and related to directly measured molar conductivities, allowing the determination of the degree of dissociation. The rotational correlation times τR ranging from 50 ps up to 2 ns as a function of temperature were compared with those obtained from high-field NMR quadrupolar relaxation time measurements addressing explicitly the rotation of the NH vector and giving insights into the acidic proton mobility. The Stokes-Einstein and Stokes-Einstein-Debye relations were applied to relate the diffusion coefficients and rotational correlation times to the macroscopic bulk viscosity. The results were also discussed with respect to the archetypical PIL ethylammonium nitrate.
Collapse
Affiliation(s)
- Viviane Overbeck
- Department LL&M, University of Rostock, Albert-Einstein-Str. 25, 18059 Rostock, Germany. and Physical and Theoretical Chemistry, Department of Chemistry, University of Rostock, Dr-Lorenz-Weg 2, 18059 Rostock, Germany
| | - Henning Schröder
- Department of Mathematics, University of Rostock, Ulmenstr. 69, 18057 Rostock, Germany
| | - Anne-Marie Bonsa
- Department LL&M, University of Rostock, Albert-Einstein-Str. 25, 18059 Rostock, Germany. and Physical and Theoretical Chemistry, Department of Chemistry, University of Rostock, Dr-Lorenz-Weg 2, 18059 Rostock, Germany
| | - Klaus Neymeyr
- Department of Mathematics, University of Rostock, Ulmenstr. 69, 18057 Rostock, Germany
| | - Ralf Ludwig
- Department LL&M, University of Rostock, Albert-Einstein-Str. 25, 18059 Rostock, Germany. and Physical and Theoretical Chemistry, Department of Chemistry, University of Rostock, Dr-Lorenz-Weg 2, 18059 Rostock, Germany and Leibniz Institute for Catalysis e.V., Albert-Einstein-Str. 29a, 18059 Rostock, Germany
| |
Collapse
|
17
|
Abstract
The extent to which cations and anions in ionic liquids (ILs) and ionic liquid solutions are dissociated is of both fundamental scientific interest and practical importance because ion dissociation has been shown to impact viscosity, density, surface tension, volatility, solubility, chemical reactivity, and many other important chemical and physical properties. When mixed with solvents, ionic liquids provide the unique opportunity to investigate ion dissociation from infinite dilution in the solvent to a completely solvent-free state, even at ambient conditions. The most common way to estimate ion dissociation in ILs and IL solutions is by comparing the molar conductivity determined from ionic conductivity measurements such as electrochemical impedance spectroscopy (EIS) (which measure the movement of only the charged, i.e., dissociated, ions) with the molar conductivity calculated from ion diffusivities measured by pulse field gradient nuclear magnetic resonance spectroscopy (PFG-NMR, which gives movement of all of the ions). Because the NMR measurements are time-consuming, the number of ILs and IL solutions investigated by this method is relatively limited. We have shown that use of the Stokes-Einstein equation with estimates of the effective ion Stokes radii allows ion dissociation to be calculated from easily measured density, viscosity, and ionic conductivity data (ρ, η, λ), which is readily available in the literature for a much larger number of pure ILs and IL solutions. Therefore, in this review, we present values of ion dissociation for ILs and IL solutions (aqueous and nonaqueous) determined by both the traditional molar conductivity/PFG-NMR method and the ρ, η, λ method. We explore the effect of cation and anion alkyl chain length, structure, and interaction motifs of the cation and anion, temperature, and the strength of the solvent in IL solutions.
Collapse
Affiliation(s)
- Oscar Nordness
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
| | - Joan F Brennecke
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
| |
Collapse
|
18
|
Dynamics of Ionic Liquids in Confinement by Means of NMR Relaxometry-EMIM-FSI in a Silica Matrix as an Example. MATERIALS 2020; 13:ma13194351. [PMID: 33007881 PMCID: PMC7579494 DOI: 10.3390/ma13194351] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 09/17/2020] [Accepted: 09/21/2020] [Indexed: 02/07/2023]
Abstract
1H and 19F spin–lattice relaxation studies for 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide in bulk and mesoporous MCM-41 silica matrix confinement were performed under varying temperatures in a broad range of magnetic fields, corresponding to 1H resonance frequency from 5Hz to 30MHz.A thorough analysis of the relaxation data revealed a three-dimensional translation diffusion of the ions in the bulk liquid and two-dimensional diffusion in the vicinity of the confining walls in the confinement. Parameters describing the translation dynamics were determined and compared. The rotational motion of both kinds of ions in the confinement was described by two correlation times that might be attributed to anisotropic reorientation of these species.
Collapse
|
19
|
Jayakody NK, Fraenza CC, Greenbaum SG, Ashby D, Dunn BS. NMR Relaxometry and Diffusometry Analysis of Dynamics in Ionic Liquids and Ionogels for Use in Lithium-Ion Batteries. J Phys Chem B 2020; 124:6843-6856. [DOI: 10.1021/acs.jpcb.0c02755] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Nishani Kanchana Jayakody
- Department of Physics and Astronomy, Hunter College of CUNY, New York, New York 10065, United States
| | - Carla C. Fraenza
- Department of Physics and Astronomy, Hunter College of CUNY, New York, New York 10065, United States
| | - Steven G. Greenbaum
- Department of Physics and Astronomy, Hunter College of CUNY, New York, New York 10065, United States
| | - David Ashby
- Department of Materials Science and Engineering, University of California, Los Angeles, California 90024, United States
| | - Bruce S. Dunn
- Department of Materials Science and Engineering, University of California, Los Angeles, California 90024, United States
| |
Collapse
|
20
|
Wang YL, Li B, Sarman S, Mocci F, Lu ZY, Yuan J, Laaksonen A, Fayer MD. Microstructural and Dynamical Heterogeneities in Ionic Liquids. Chem Rev 2020; 120:5798-5877. [PMID: 32292036 PMCID: PMC7349628 DOI: 10.1021/acs.chemrev.9b00693] [Citation(s) in RCA: 192] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Indexed: 12/11/2022]
Abstract
Ionic liquids (ILs) are a special category of molten salts solely composed of ions with varied molecular symmetry and charge delocalization. The versatility in combining varied cation-anion moieties and in functionalizing ions with different atoms and molecular groups contributes to their peculiar interactions ranging from weak isotropic associations to strong, specific, and anisotropic forces. A delicate interplay among intra- and intermolecular interactions facilitates the formation of heterogeneous microstructures and liquid morphologies, which further contributes to their striking dynamical properties. Microstructural and dynamical heterogeneities of ILs lead to their multifaceted properties described by an inherent designer feature, which makes ILs important candidates for novel solvents, electrolytes, and functional materials in academia and industrial applications. Due to a massive number of combinations of ion pairs with ion species having distinct molecular structures and IL mixtures containing varied molecular solvents, a comprehensive understanding of their hierarchical structural and dynamical quantities is of great significance for a rational selection of ILs with appropriate properties and thereafter advancing their macroscopic functionalities in applications. In this review, we comprehensively trace recent advances in understanding delicate interplay of strong and weak interactions that underpin their complex phase behaviors with a particular emphasis on understanding heterogeneous microstructures and dynamics of ILs in bulk liquids, in mixtures with cosolvents, and in interfacial regions.
Collapse
Affiliation(s)
- Yong-Lei Wang
- Department
of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Bin Li
- School
of Chemical Engineering and Technology, Sun Yat-sen University, Zhuhai 519082, P. R. China
| | - Sten Sarman
- Department
of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Francesca Mocci
- Department
of Chemical and Geological Sciences, University
of Cagliari, I-09042 Monserrato, Italy
| | - Zhong-Yuan Lu
- State
Key Laboratory of Supramolecular Structure and Materials, Institute
of Theoretical Chemistry, Jilin University, Changchun 130021, P. R. China
| | - Jiayin Yuan
- Department
of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Aatto Laaksonen
- Department
of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
- State
Key Laboratory of Materials-Oriented and Chemical Engineering, Nanjing Tech University, Nanjing 210009, P. R. China
- Centre of
Advanced Research in Bionanoconjugates and Biopolymers, Petru Poni Institute of Macromolecular Chemistry Aleea Grigore Ghica-Voda, 41A, 700487 Iasi, Romania
- Department
of Engineering Sciences and Mathematics, Division of Energy Science, Luleå University of Technology, SE-97187 Luleå, Sweden
| | - Michael D. Fayer
- Department
of Chemistry, Stanford University, Stanford, California 94305, United States
| |
Collapse
|
21
|
Noferini D, Holderer O, Frielinghaus H. Effect of mild nanoscopic confinement on the dynamics of ionic liquids. Phys Chem Chem Phys 2020; 22:9046-9052. [PMID: 32296792 DOI: 10.1039/c9cp05200c] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Ionic liquids are molten salts without an additional solvent and are discussed as innovative solvents and electrolytes in chemical processing and electrochemistry. A thorough microscopic understanding of the structure and ionic transport processes is essential for tailored applications. Here, we study the influence of "mild" nanoscopic confinement on the structure and diffusion properties of an ionic liquid, 1-ethyl-3-methylimidazolium acetate, using scattering techniques. The structure is analyzed by X-ray diffraction, while neutron backscattering spectroscopy is used for the study of the diffusion processes in these systems. Interpreting the diffusion processes in terms of a jump-diffusion model allowed us to deduce the confinement effects on the jump length and residence time, both increased at elevated temperatures in confinement. The applied "mild" confinement, which leaves room for 10-25 times the domain spacing, allows us to observe in great detail how the onset of domain distortion decelerates the dynamics.
Collapse
Affiliation(s)
- Daria Noferini
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Garching, Germany.
| | | | | |
Collapse
|
22
|
Kruk D, Rochowski P, Masiewicz E, Wilczynski S, Wojciechowski M, Broche LM, Lurie DJ. Mechanism of Water Dynamics in Hyaluronic Dermal Fillers Revealed by Nuclear Magnetic Resonance Relaxometry. Chemphyschem 2019; 20:2816-2822. [PMID: 31532873 PMCID: PMC6899992 DOI: 10.1002/cphc.201900761] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 09/18/2019] [Indexed: 11/23/2022]
Abstract
1 H spin-lattice nuclear magnetic resonance relaxation experiments were performed for five kinds of dermal fillers based on hyaluronic acid. The relaxation data were collected over a broad frequency range between 4 kHz and 40 MHz, at body temperature. Thanks to the frequency range encompassing four orders of magnitude, the dynamics of water confined in the polymeric matrix was revealed. It is demonstrated that translation diffusion of the confined water molecules exhibits a two-dimensional character and the diffusion process is slower than diffusion in bulk water by 3-4 orders of magnitude. As far as rotational dynamics of the confined water is concerned, it is shown that in all cases there is a water pool characterized by a rotational correlation time of about 4×10-9 s. In some of the dermal fillers a fraction of the confined water (about 10 %) forms a pool that exhibits considerably slower (by an order of magnitude) rotational dynamics. In addition, the water binding capacity of the dermal fillers was quantitatively compared.
Collapse
Affiliation(s)
- Danuta Kruk
- Faculty of Mathematics and Computer ScienceUniversity of Warmia & Mazury in OlsztynSłoneczna 5410-710OlsztynPoland
| | - Pawel Rochowski
- Faculty of Mathematics and Computer ScienceUniversity of Warmia & Mazury in OlsztynSłoneczna 5410-710OlsztynPoland
- Current affiliation:Faculty of Mathematics, Physics and InformaticsGdansk UniversityWita Stwosza 5780-308GdanskPoland
| | - Elzbieta Masiewicz
- Faculty of Mathematics and Computer ScienceUniversity of Warmia & Mazury in OlsztynSłoneczna 5410-710OlsztynPoland
| | - Slawomir Wilczynski
- Department of Basic Biomedical Science School of PharmacyMedical University of Silesia in KatowiceKasztanowa 341-200SosnowiecPoland
| | - Milosz Wojciechowski
- Faculty of Mathematics and Computer ScienceUniversity of Warmia & Mazury in OlsztynSłoneczna 5410-710OlsztynPoland
| | - Lionel M. Broche
- Bio-Medical Physics School of Medicine Medical Sciences & NutritionUniversity of Aberdeen ForesterhillAberdeenAB25 2ZD, ScotlandUnited Kingdom
| | - David J. Lurie
- Bio-Medical Physics School of Medicine Medical Sciences & NutritionUniversity of Aberdeen ForesterhillAberdeenAB25 2ZD, ScotlandUnited Kingdom
| |
Collapse
|
23
|
Flämig M, Hofmann M, Lichtinger A, Rössler EA. Application of proton field-cycling NMR relaxometry for studying translational diffusion in simple liquids and polymer melts. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2019; 57:805-817. [PMID: 30604576 DOI: 10.1002/mrc.4823] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 12/19/2018] [Accepted: 12/20/2018] [Indexed: 06/09/2023]
Abstract
With the availability of commercial field-cycling relaxometers together with progress of home-built instruments nuclear magnetic resonance relaxometry has gained new momentum as a method of investigating the dynamics in viscous liquids and polymer melts. The method provides the frequency dependence of the spin-lattice relaxation rate. In the case of protons, one distinguishes intramolecular and intermolecular relaxation pathways. Whereas the intramolecular contribution prevails at high frequencies and reflects rotational dynamics, the often ignored intermolecular relaxation contribution dominates at low-frequency and provides access to translational dynamics. A universal low-frequencies dispersion law holds which in pure systems allows determining the diffusion coefficient in a straightforward way. In addition, the rotational time constant is extracted from the high-frequency relaxation contribution. This is demonstrated for simple and ionic liquids and for polymer melts.
Collapse
Affiliation(s)
- Max Flämig
- Experimentalphysik and Nordbayerisches NMR-Zentrum, Universität Bayreuth, Bayreuth, Germany
| | - Marius Hofmann
- Experimentalphysik and Nordbayerisches NMR-Zentrum, Universität Bayreuth, Bayreuth, Germany
| | - Anne Lichtinger
- Experimentalphysik and Nordbayerisches NMR-Zentrum, Universität Bayreuth, Bayreuth, Germany
| | - Ernst A Rössler
- Experimentalphysik and Nordbayerisches NMR-Zentrum, Universität Bayreuth, Bayreuth, Germany
| |
Collapse
|
24
|
Wiedemann C, Hempel G, Bordusa F. Reorientation dynamics and ion diffusivity of neat dimethylimidazolium dimethylphosphate probed by NMR spectroscopy. RSC Adv 2019; 9:35735-35750. [PMID: 35528082 PMCID: PMC9074696 DOI: 10.1039/c9ra07731f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 10/28/2019] [Indexed: 11/21/2022] Open
Abstract
NMR spectroscopy at two magnetic field strengths was employed to investigate the dynamics of dimethylimidazolium dimethylphosphate ([C1C1IM][(CH3)2PO4]). [C1C1IM][(CH3)2PO4] is a low-melting, halogen-free ionic liquid comprising of only methyl groups. 13C spin–lattice relaxation rates as well as self-diffusion coefficients were measured for [C1C1IM][(CH3)2PO4] as a function of temperature. The rotational correlation times, τc, for the cation and the anion were obtained from the 13C spin–lattice relaxation rates. Although from a theoretical point of view cations and anions are similar in size, they show different reorientation mobilities and diffusivities. The self-diffusion coefficients and the rotational correlation times were related to the radii of the diffusing spheres. The analysis reveals that the radii of the cation and the anion, respectively, are different from each other but constant at temperatures ranging from 293 to 353 K. The experimental results are rationalised by a discrete and individual cation and anion diffusion. The [(CH3)2PO4]− anion reorients faster compared to the cation but diffuses significantly slower indicating the formation of anionic aggregates. Relaxation data were acquired with standard liquid and magic-angle-spinning NMR probes to estimate residual dipolar interactions, chemical shift anisotropy or differences in magnetic susceptibility within the sample. Liquid and HR-MAS NMR spectroscopy at two magnetic field strengths was employed to investigate the dynamics of ([C1C1IM][(CH3)2PO4]).![]()
Collapse
Affiliation(s)
- Christoph Wiedemann
- Institute of Biochemistry and Biotechnology
- Charles Tanford Protein Center
- Martin Luther University Halle-Wittenberg
- D-06120 Halle (Saale)
- Germany
| | - Günter Hempel
- Institute of Physics
- Martin Luther University Halle-Wittenberg
- D-06120 Halle (Saale)
- Germany
| | - Frank Bordusa
- Institute of Biochemistry and Biotechnology
- Charles Tanford Protein Center
- Martin Luther University Halle-Wittenberg
- D-06120 Halle (Saale)
- Germany
| |
Collapse
|
25
|
Fries PH, Belorizky E. Theory of fast field-cycling NMR relaxometry of liquid systems undergoing chemical exchange. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1538539] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
| | - Elie Belorizky
- CEA-LETI, Grenoble, France
- Univ. Grenoble Alpes, Grenoble, France
| |
Collapse
|
26
|
Robinson N, Robertson C, Gladden LF, Jenkins SJ, D'Agostino C. Direct Correlation between Adsorption Energetics and Nuclear Spin Relaxation in a Liquid-saturated Catalyst Material. Chemphyschem 2018; 19:2472-2479. [PMID: 29923663 DOI: 10.1002/cphc.201800513] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Indexed: 11/09/2022]
Abstract
The ratio of NMR relaxation time constants <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:msub><mml:mi>T</mml:mi> <mml:mn>1</mml:mn></mml:msub> <mml:mo>/</mml:mo> <mml:msub><mml:mi>T</mml:mi> <mml:mn>2</mml:mn></mml:msub> </mml:mrow> </mml:math> provides a non-destructive indication of the relative surface affinities exhibited by adsorbates within liquid-saturated mesoporous catalysts. In the present work we provide supporting evidence for the existence of a quantitative relationship between such measurements and adsorption energetics. As a prototypical example with relevance to green chemical processes we examine and contrast the relaxation characteristics of primary alcohols and cyclohexane within an industrial silica catalyst support. <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:msub><mml:mi>T</mml:mi> <mml:mn>1</mml:mn></mml:msub> <mml:mo>/</mml:mo> <mml:msub><mml:mi>T</mml:mi> <mml:mn>2</mml:mn></mml:msub> </mml:mrow> </mml:math> values obtained at intermediate magnetic field strength are in good agreement with DFT adsorption energy calculations performed on single molecules interacting with an idealised silica surface. Our results demonstrate the remarkable ability of this metric to quantify surface affinities within systems of relevance to liquid-phase heterogeneous catalysis, and highlight NMR relaxation as a powerful method for the determination of adsorption phenomena within mesoporous solids.
Collapse
Affiliation(s)
- Neil Robinson
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS, United Kingdom.,Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, United Kingdom
| | - Christopher Robertson
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS, United Kingdom
| | - Lynn F Gladden
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS, United Kingdom
| | - Stephen J Jenkins
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, United Kingdom
| | - Carmine D'Agostino
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS, United Kingdom.,Present address: School of Chemical Engineering and Analytical Science, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
| |
Collapse
|
27
|
Smith CJ, Gehrke S, Hollóczki O, Wagle DV, Heitz MP, Baker GA. NMR relaxometric probing of ionic liquid dynamics and diffusion under mesoscopic confinement within bacterial cellulose ionogels. J Chem Phys 2018; 148:193845. [PMID: 30307178 DOI: 10.1063/1.5016337] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Chip J. Smith
- Department of Chemistry, University of Missouri-Columbia, Columbia, Missouri 65211, USA
| | - Sascha Gehrke
- Mulliken Center for Theoretical Chemistry, University of Bonn, Beringstr. 4+6, Bonn 53115, Germany
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, Muelheim an der Ruhr 45470, Germany
| | - Oldamur Hollóczki
- Mulliken Center for Theoretical Chemistry, University of Bonn, Beringstr. 4+6, Bonn 53115, Germany
| | - Durgesh V. Wagle
- Department of Chemistry, University of Missouri-Columbia, Columbia, Missouri 65211, USA
| | - Mark P. Heitz
- Department of Chemistry and Biochemistry, The College at Brockport SUNY, Brockport, New York 14420, USA
| | - Gary A. Baker
- Department of Chemistry, University of Missouri-Columbia, Columbia, Missouri 65211, USA
| |
Collapse
|