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Phani Kumar BVN, Lobo NP, Mattea C, Stapf S. Exploring Crystal-Phase Molecular Dynamics of the Low-Viscous Mesogen 6CHBT: A Combined FFC and High-Field NMR Relaxometry Investigation. J Phys Chem B 2024; 128:3997-4007. [PMID: 38616575 DOI: 10.1021/acs.jpcb.3c08259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
The molecular dynamics study of thermotropic mesogens exhibiting the crystal phases is valuable in unraveling the complex global (collective) and local (noncollective) motions executed by liquid crystal molecules, which would further advance the existing knowledge on orientationally disordered crystalline (ODIC) phases. Toward the fulfillment of such a task, a combined nuclear magnetic resonance (NMR) relaxometry approach employing the fast field cycling (FFC) NMR (10 kHz-30 MHz) and high-field pulsed NMR (400 MHz) techniques is utilized to sample the broad frequency range offered by molecular motions in the crystal phase of 4-(trans-4'-n-hexylcyclohexyl)-isothiocyanatobenzene (6CHBT). The validity of the observed relaxation data is tested and interpreted by the Bloembergen-Purcell-Pound (BPP) model involving the superposition of four mutually independent Lorentzian spectral densities, reflecting molecular dynamical processes on different time scales. The salient feature of the detailed analysis reveals that the lengthening of temporal dynamics in the crystal phase due to molecular rotations by jumps, which are of intermolecular origin, is evident and further supports the presence of collective-like local dynamics. The analysis does permit decoupling of the molecular reorientations about their short axes (∼100 ns) as well as long axes (∼50 ns) and methyl group rotations (∼0.5 ns) on distinct time scales. The activation energies for reorientations about the short axes and methyl group rotations are found to be 27.3 ± 2.7 and 15.8 ± 1.1 kJ/mol, respectively. The fast methyl rotations in the crystal phase of 6CHBT obtained from FFC NMR are further well complemented by high-field NMR, where 1H NMR line shapes are relatively narrow when compared to those of the nematic phase.
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Affiliation(s)
- Bandaru V N Phani Kumar
- Department of Technical Physics II/Polymer Physics, Institute of Physics, Ilmenau University of Technology, PO Box 100565, D-98684 Ilmenau, Germany
- NMR, Centre for Analysis, Testing, Evaluation & Reporting Services (CATERS), CSIR-Central Leather Research Institute, Chennai 600020, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Nitin P Lobo
- NMR, Centre for Analysis, Testing, Evaluation & Reporting Services (CATERS), CSIR-Central Leather Research Institute, Chennai 600020, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Carlos Mattea
- Department of Technical Physics II/Polymer Physics, Institute of Physics, Ilmenau University of Technology, PO Box 100565, D-98684 Ilmenau, Germany
| | - Siegfried Stapf
- Department of Technical Physics II/Polymer Physics, Institute of Physics, Ilmenau University of Technology, PO Box 100565, D-98684 Ilmenau, Germany
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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.
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Dynamics of Solid Proteins by Means of Nuclear Magnetic Resonance Relaxometry. Biomolecules 2019; 9:biom9110652. [PMID: 31731514 PMCID: PMC6920843 DOI: 10.3390/biom9110652] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 10/16/2019] [Accepted: 10/19/2019] [Indexed: 01/21/2023] Open
Abstract
1H Nuclear magnetic resonance (NMR) relaxometry was exploited to investigate the dynamics of solid proteins. The relaxation experiments were performed at 37 °C over a broad frequency range, from approximately 10 kHz to 40 MHz. Two relaxation contributions to the overall 1H spin-lattice relaxation were revealed; they were associated with 1H-1H and 1H-14N magnetic dipole-dipole interactions, respectively. The 1H-1H relaxation contribution was interpreted in terms of three dynamical processes occurring on timescales of 10-6 s, 10-7 s, and 10-8 s, respectively. The 1H-14N relaxation contribution shows quadrupole relaxation enhancement effects. A thorough analysis of the data was performed revealing similarities in the protein dynamics, despite their different structures. Among several parameters characterizing the protein dynamics and structure (e.g., electric field gradient tensor at the position of 14N nuclei), the orientation of the 1H-14N dipole-dipole axis, with respect to the principal axis system of the electric field gradient, was determined, showing that, for lysozyme, it was considerably different than for the other proteins. Moreover, the validity range of a closed form expression describing the 1H-14N relaxation contribution was determined by a comparison with a general approach based on the stochastic Liouville equation.
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Kubica-Misztal A, Rochowski P, Florek-Wojciechowska M, Kruk D. Dynamics of solid alanine by means of nuclear magnetic resonance relaxometry. J Chem Phys 2018; 146:164501. [PMID: 28456185 DOI: 10.1063/1.4980152] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
1H nuclear magnetic resonance relaxometry was applied to investigate the dynamics of l-alanine in the solid phase (powder). The experimental studies were carried out in a very broad frequency range, covering four orders of magnitude-from 4 kHz to 40 MHz (referring to the 1H resonance frequency) in order to probe motional processes of much different time scales by a single experiment. To get access to the dynamics of different proton groups of alanine, the 1H spin-lattice relaxation measurements were performed for non-deuterated and partially deuterated alanine. The experiments were carried out in the temperature range of 293 K-370 K (non-deuterated alanine) and 318 K-370 K (partially deuterated alanine). As a result of a thorough theoretical analysis of the extensive set of experimental results, three motional processes occurring on different time scales are identified and quantitatively described. The slowest process occurs on a time scale of μs and it is attributed to the collective dynamics of a 3D hydrogen bond network of alanine, while the intermediate, attributed to the dynamics of the NH3 group, corresponds to the range of tenths of ns. The fast process describes the rotation of the CH3 group.
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Affiliation(s)
- A Kubica-Misztal
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, Łojasiewicza 11, 30-348 Kraków, Poland
| | - P Rochowski
- Faculty of Mathematics and Computer Science, University of Warmia and Mazury in Olsztyn, Słoneczna 54, 10-710 Olsztyn, Poland
| | - M Florek-Wojciechowska
- Department of Physics and Biophysics, University of Warmia and Mazury in Olsztyn, Oczapowskiego 4, 10-719 Olsztyn, Poland
| | - D Kruk
- Faculty of Mathematics and Computer Science, University of Warmia and Mazury in Olsztyn, Słoneczna 54, 10-710 Olsztyn, Poland
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Gineste S, Di Cola E, Amouroux B, Till U, Marty JD, Mingotaud AF, Mingotaud C, Violleau F, Berti D, Parigi G, Luchinat C, Balor S, Sztucki M, Lonetti B. Mechanistic Insights into Polyion Complex Associations. Macromolecules 2018. [DOI: 10.1021/acs.macromol.7b02391] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Stéphane Gineste
- Laboratoire
des IMRCP, Université de Toulouse, CNRS UMR 5623, Université Toulouse III - Paul Sabatier, 118 route de Narbonne, Cedex 9 F-31062, Toulouse, France
| | - Emanuela Di Cola
- BioSoftMatter
Laboratorio Dip CBBM LITA, Universita di Milano, Via F lli Cervi
93 MI IT, 20090 Segrate, Italy
| | - Baptiste Amouroux
- Laboratoire
des IMRCP, Université de Toulouse, CNRS UMR 5623, Université Toulouse III - Paul Sabatier, 118 route de Narbonne, Cedex 9 F-31062, Toulouse, France
| | - Ugo Till
- Laboratoire
des IMRCP, Université de Toulouse, CNRS UMR 5623, Université Toulouse III - Paul Sabatier, 118 route de Narbonne, Cedex 9 F-31062, Toulouse, France
- Département
Sciences Agronomiques et Agroalimentaires, Université de Toulouse, Institut National Polytechnique de Toulouse - Ecole d’Ingénieurs de Purpan, 75 voie du TOEC, BP 57611, Cedex 03 F-31076 Toulouse, France
| | - Jean-Daniel Marty
- Laboratoire
des IMRCP, Université de Toulouse, CNRS UMR 5623, Université Toulouse III - Paul Sabatier, 118 route de Narbonne, Cedex 9 F-31062, Toulouse, France
| | - Anne-Françoise Mingotaud
- Laboratoire
des IMRCP, Université de Toulouse, CNRS UMR 5623, Université Toulouse III - Paul Sabatier, 118 route de Narbonne, Cedex 9 F-31062, Toulouse, France
| | - Christophe Mingotaud
- Laboratoire
des IMRCP, Université de Toulouse, CNRS UMR 5623, Université Toulouse III - Paul Sabatier, 118 route de Narbonne, Cedex 9 F-31062, Toulouse, France
| | - Frédéric Violleau
- Laboratoire
de Chimie Agro-industrielle (LCA), Université de Toulouse, INRA, INPT, INP-EI PURPAN, Toulouse, France
| | - Debora Berti
- Department
of Chemistry “Ugo Schiff”, University of Florence and CSGI, Via della Lastruccia 3, 50019 Sesto Fiorentino Firenze, Italy
| | - Giacomo Parigi
- Department
of Chemistry Ugo Schiff and Magnetic Resonance Center (CERM), University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino Firenze, Italy
| | - Claudio Luchinat
- Department
of Chemistry Ugo Schiff and Magnetic Resonance Center (CERM), University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino Firenze, Italy
| | - Stéphanie Balor
- Plateforme
METi, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Michael Sztucki
- European Synchrotron
Radiation Facility-71, avenue des Martyrs,
CS 40220, Cedex 9 38043 Grenoble, France
| | - Barbara Lonetti
- Laboratoire
des IMRCP, Université de Toulouse, CNRS UMR 5623, Université Toulouse III - Paul Sabatier, 118 route de Narbonne, Cedex 9 F-31062, Toulouse, France
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Kimmich R, Fatkullin N. Self-diffusion studies by intra- and inter-molecular spin-lattice relaxometry using field-cycling: Liquids, plastic crystals, porous media, and polymer segments. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2017; 101:18-50. [PMID: 28844220 DOI: 10.1016/j.pnmrs.2017.04.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 04/02/2017] [Accepted: 04/02/2017] [Indexed: 06/07/2023]
Abstract
Field-cycling NMR relaxometry is a well-established technique for probing molecular dynamics in a frequency range from typically a few kHz up to several tens of MHz. For the interpretation of relaxometry data, it is quite often assumed that the spin-lattice relaxation process is of an intra-molecular nature so that rotational fluctuations dominate. However, dipolar interactions as the main type of couplings between protons and other dipolar species without quadrupole moments can imply appreciable inter-molecular contributions. These fluctuate due to translational displacements and to a lesser degree also by rotational reorientations in the short-range limit. The analysis of the inter-molecular proton spin-lattice relaxation rate thus permits one to evaluate self-diffusion variables such as the diffusion coefficient or the mean square displacement on a time scale from nanoseconds to several hundreds of microseconds. Numerous applications to solvents, plastic crystals and polymers will be reviewed. The technique is of particular interest for polymer dynamics since inter-molecular spin-lattice relaxation diffusometry bridges the time scales of quasi-elastic neutron scattering and field-gradient NMR diffusometry. This is just the range where model-specific intra-coil mechanisms are assumed to occur. They are expected to reveal themselves by characteristic power laws for the time-dependence of the mean-square segment displacement. These can be favorably tested on this basis. Results reported in the literature will be compared with theoretical predictions. On the other hand, there is a second way for translational diffusion phenomena to affect the spin-lattice relaxation dispersion. If rotational diffusion of molecules is restricted, translational diffusion properties can be deduced even from molecular reorientation dynamics detected by intra-molecular spin-lattice relaxation. This sort of scenario will be relevant for adsorbates on surfaces or polymer segments under entanglement and chain connectivity constraints. Under such conditions, reorientations will be correlated with translational displacements leading to the so-called RMTD relaxation process (reorientation mediated by translational displacements). Applications to porous glasses, protein solutions, lipid bilayers, and clays will be discussed. Finally, we will address the intriguing fact that the various time limits of the segment mean-square displacement of polymers in some cases perfectly reproduce predictions of the tube/reptation model whereas the reorientation dynamics suggests strongly deviating power laws.
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Affiliation(s)
| | - Nail Fatkullin
- Institute of Physics, Kazan Federal University, Kazan 420008 Tatarstan, Russia
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