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Błażytko A, Rams-Baron M, Paluch M. The influence of molecular shape on reorientation dynamics of sizable glass-forming isomers at ambient and elevated pressure. Sci Rep 2024; 14:887. [PMID: 38195815 PMCID: PMC10776563 DOI: 10.1038/s41598-023-50894-8] [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: 11/07/2023] [Accepted: 12/27/2023] [Indexed: 01/11/2024] Open
Abstract
We used dielectric spectroscopy to access the molecular dynamics of three isomers with a structure based on a sizable, partially rigid, and non-polar core connected to a polar phenylene unit differing in the position of the polar group, and, consequently, the direction and magnitude of the dipole moment to address the question how unique molecular properties, in particular large size and elongated shape, affect the dynamics. The position of the polar group differentiates the molecular shape and isomer's anisotropy and leads to different thermal and dynamic properties of the isomers. The shape of permittivity loss spectra was governed by magnitudes of the longitudinal and transverse components of dipole moment to a large extent. For para isomer with negligible traverse component of dipole moment, the narrowest loss peak was found while for meta isomer, the bimodal loss peak was observed at high temperatures. Its shape evolved on cooling limiting the possibility of individual mode separation near glass transition where the dynamics were more cooperative. High-pressure dielectric studies showed that sizable isomers were characterized by the pronounced sensitivity of glass transition temperature, Tg, to compression. Observed high activation volumes, such as 735 cm3/mol at Tg for para isomer, were found to correlate with the length scale of dynamic cooperativity. The number of dynamically correlated molecules depended on molecular shape and varied among isomers while the determined values were much smaller than that reported for other glass-forming liquids. We discussed here the obtained results in the context of the specific properties of the systems studied showing the overriding role of anisotropy.
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Affiliation(s)
- Alfred Błażytko
- August Chełkowski Institute of Physics, University of Silesia in Katowice, 75 Pułku Piechoty 1, 41-500, Chorzow, Poland
| | - Marzena Rams-Baron
- August Chełkowski Institute of Physics, University of Silesia in Katowice, 75 Pułku Piechoty 1, 41-500, Chorzow, Poland.
| | - Marian Paluch
- August Chełkowski Institute of Physics, University of Silesia in Katowice, 75 Pułku Piechoty 1, 41-500, Chorzow, Poland
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2
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Hellwig H, Nowok A, Peksa P, Dulski M, Musioł R, Pawlus S, Kuś P. Molecular Dynamics and Near- Tg Phenomena of Cyclic Thioethers. Int J Mol Sci 2023; 24:17166. [PMID: 38138995 PMCID: PMC10742681 DOI: 10.3390/ijms242417166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 11/20/2023] [Accepted: 12/02/2023] [Indexed: 12/24/2023] Open
Abstract
This article presents the synthesis and molecular dynamics investigation of three novel cyclic thioethers: 2,3-(4'-methylbenzo)-1,4,7,10-tetrathiacyclododeca-2-ene (compound 1), 2,3,14,15-bis(4',4″(5″)-methylbenzo)-1,4,7,10,13,16,19,22,25-octathiacyclotetracosa-2,14-diene (compound 2), and 2,3,8,9-bis(4',4″(5″)-methylbenzo)-1,4,7,10-tetrathiacyclododeca-2,8-diene (compound 3). The compounds exhibit relatively high glass transition temperatures (Tg), which range between 254 and 283 K. This characteristic positions them within the so-far limited category of crown-like glass-formers. We demonstrate that cyclic thioethers may span both the realms of ordinary and sizeable molecular glass-formers, each featuring distinct physical properties. Furthermore, we show that the Tg follows a sublinear power law as a function of the molar mass within this class of compounds. We also reveal multiple dielectric relaxation processes of the novel cyclic thioethers. Above the Tg, their dielectric loss spectra are dominated by a structural relaxation, which originates from the cooperative reorientation of entire molecules and exhibits an excess wing on its high-frequency slope. This feature has been attributed to the Johari-Goldstein (JG) process. Each investigated compound exhibits also at least one intramolecular secondary non-JG relaxation stemming from conformational changes. Their activation energies range from approximately 19 kJ/mol to roughly 40 kJ/mol. Finally, we analyze the high-pressure molecular dynamics of compound 1, revealing a pressure-induced increase in its Tg with a dTg/dp coefficient equal to 197 ± 8 K/GPa.
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Affiliation(s)
- Hubert Hellwig
- Center for Integrated Technology and Organic Synthesis (CiTOS), MolSys Research Unit, University of Liège, B6a, Room 3/19, Allée du Six Août 13, 4000 Liege, Belgium;
| | - Andrzej Nowok
- Department of Experimental Physics, Wrocław University of Science and Technology, Wybrzeże Stanisława Wyspiańskiego 27, 50-370 Wrocław, Poland; (A.N.); (P.P.)
| | - Paulina Peksa
- Department of Experimental Physics, Wrocław University of Science and Technology, Wybrzeże Stanisława Wyspiańskiego 27, 50-370 Wrocław, Poland; (A.N.); (P.P.)
| | - Mateusz Dulski
- Faculty of Science and Technology, Institute of Materials Engineering, University of Silesia in Katowice, 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland;
| | - Robert Musioł
- Institute of Chemistry, University of Silesia in Katowice, Szkolna 9, 40-003 Katowice, Poland;
| | - Sebastian Pawlus
- August Chełkowski Institute of Physics, University of Silesia in Katowice, 75 Pułku Piechoty 1, 41-500 Chorzów, Poland;
| | - Piotr Kuś
- Institute of Chemistry, University of Silesia in Katowice, Szkolna 9, 40-003 Katowice, Poland;
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Simple Rules for Complex Near-Glass-Transition Phenomena in Medium-Sized Schiff Bases. Int J Mol Sci 2022; 23:ijms23095185. [PMID: 35563574 PMCID: PMC9103181 DOI: 10.3390/ijms23095185] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Revised: 05/01/2022] [Accepted: 05/03/2022] [Indexed: 02/04/2023] Open
Abstract
Glass-forming ability is one of the most desired properties of organic compounds dedicated to optoelectronic applications. Therefore, finding general structure–property relationships and other rules governing vitrification and related near-glass-transition phenomena is a burning issue for numerous compound families, such as Schiff bases. Hence, we employ differential scanning calorimetry, broadband dielectric spectroscopy, X-ray diffraction and quantum density functional theory calculations to investigate near-glass-transition phenomena, as well as ambient- and high-pressure molecular dynamics for two structurally related Schiff bases belonging to the family of glycine imino esters. Firstly, the surprising great stability of the supercooled liquid phase is shown for these compounds, also under high-pressure conditions. Secondly, atypical self-organization via bifurcated hydrogen bonds into lasting centrosymmetric dimers is proven. Finally, by comparing the obtained results with the previous report, some general rules that govern ambient- and high-pressure molecular dynamics and near-glass transition phenomena are derived for the family of glycine imino esters. Particularly, we derive a mathematical formula to predict and tune their glass transition temperature (Tg) and its pressure coefficient (dTg/dp). We also show that, surprisingly, despite the presence of intra- and intermolecular hydrogen bonds, van der Waals and dipole–dipole interactions are the main forces governing molecular dynamics and dielectric properties of glycine imino esters.
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Heczko D, Jesionek P, Hachuła B, Jurkiewicz K, Grelska J, Tarnacka M, Kamiński K, Paluch M, Kamińska E. Variation in the local ordering, H-bonding pattern and molecular dynamics in the pressure densified ritonavir. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.118666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Rams-Baron M, Yao B, Cheng S, Dulski M, Paluch M. Complex Reorientation Dynamics of Sizable Glass-Formers with Polar Rotors Revealed by Dielectric Spectroscopy. J Phys Chem Lett 2021; 12:11303-11307. [PMID: 34780195 PMCID: PMC8630796 DOI: 10.1021/acs.jpclett.1c03088] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 11/05/2021] [Indexed: 06/13/2023]
Abstract
We present the results of dielectric measurements for three sizable glass-formers with identical nonpolar cores linked to various dipole-labeled rotors that shed new light on the picture of reorientation of anisotropic systems with significant moment of inertia revealed by broadband dielectric spectroscopy. The dynamics of sizable glass-formers formed by partially rigid molecular cores linked to small polar rotors in many respects differs from that of typical glass-formers. For instance, the extraordinarily large prefactors (τ0 > 10-12 s) in the Vogel-Fulcher-Tammann equation were found. The rich and highly diverse relaxation pattern was governed by the location of a dipole, its ability to rotate freely, and the degree of coupling to the motion of the entire sizable system.
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Affiliation(s)
- Marzena Rams-Baron
- August
Chełkowski Institute of Physics, University
of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland
- Silesian
Center for Education and Interdisciplinary Research, 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
| | - Beibei Yao
- August
Chełkowski Institute of Physics, University
of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland
- Silesian
Center for Education and Interdisciplinary Research, 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
| | - Shinian Cheng
- August
Chełkowski Institute of Physics, University
of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland
- Silesian
Center for Education and Interdisciplinary Research, 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
| | - Mateusz Dulski
- Institute
of Materials Engineering, University of
Silesia, 75 Pulku Piechoty
1a, 41-500 Chorzow, Poland
- Silesian
Center for Education and Interdisciplinary Research, 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
| | - Marian Paluch
- August
Chełkowski Institute of Physics, University
of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland
- Silesian
Center for Education and Interdisciplinary Research, 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
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Rams-Baron M, Jedrzejowska A, Jurkiewicz K, Matussek M, Ngai KL, Paluch M. Broadband Dielectric Study of Sizable Molecular Glass Formers: Relationship Between Local Structure and Dynamics. J Phys Chem Lett 2021; 12:245-249. [PMID: 33331778 DOI: 10.1021/acs.jpclett.0c03377] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
In this Letter we report significant differences in the dielectric behavior of four nonpolymeric and sizable glass-forming molecules with related chemical structures. They belong to the recently constituted class of sizable glass-formers [Jedrzejowska et al. Phys. Rev. E: Stat. Phys., Plasmas, Fluids, Relat. Interdiscip. Top. 2020, 101, 010603], for which the pattern of change in dielectric properties with structure has not yet been fully discovered. In the present study we tackle the fundamental problem of the structure-dynamics relationship. It was made possible by judicious choice of investigated systems with the values of dipole moments purposely kept at about the same level, and the only difference is the structure of the terminal substituents applied. The remarkable effect revealed by broadband dielectric spectroscopy is a large difference in the frequency dispersion of the α-relaxation for the systems studied. This interesting finding can be rationalized by the results of X-ray diffraction, clearly indicating the dissimilarities in the local intermolecular structure.
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Affiliation(s)
- M Rams-Baron
- August Chełkowski Institute of Physics, University of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland
- Silesian Center for Education and Interdisciplinary Research, 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
| | - A Jedrzejowska
- PET Diagnostics Department, Maria Sklodowska-Curie Memorial Cancer Centre and Institute of Oncology, Gliwice Branch, Poland
| | - K Jurkiewicz
- August Chełkowski Institute of Physics, University of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland
- Silesian Center for Education and Interdisciplinary Research, 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
| | - M Matussek
- Institute of Chemistry, University of Silesia, Szkolna 9, 40-006 Katowice, Poland
| | - K L Ngai
- CNR-IPCF, Largo Bruno Pontecorvo 3, I-56127 Pisa, Italy
| | - M Paluch
- August Chełkowski Institute of Physics, University of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland
- Silesian Center for Education and Interdisciplinary Research, 75 Pulku Piechoty 1a, 41-500 Chorzow, Poland
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Interplay between structural static and dynamical parameters as a key factor to understand peculiar behaviour of associated liquids. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.114084] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Körber T, Krohn F, Neuber C, Schmidt HW, Rössler EA. Main and secondary relaxations of non-polymeric high-T g glass formers as revealed by dielectric spectroscopy. Phys Chem Chem Phys 2020; 22:9086-9097. [PMID: 32300764 DOI: 10.1039/d0cp00930j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of high-Tg glass formers with Tg values varying between 347 and 390 K and molar masses in the range of 341 and 504 g mol-1 are investigated by dielectric spectroscopy. They are compared to paradigmatic reference systems. Differently polar side groups are attached to a rigid non-polar core unit at different positions. Thereby, the dielectric relaxation strength varies over more than two decades. All the relaxation features typical of molecular glass formers are rediscovered, i.e. stretching of the main (α-) relaxation, a more or less pronounced secondary (β-) process, and a fragility index quite similar to that of other molecular systems. The position of the polar nitrile side group influences the manifestation of the β-relaxation. The α-relaxation stretching displays the trend to become less with higher relaxation strength Δεα, confirming recent reports. Typical for a generic β-process is the increase of its amplitude above Tg, which is found to follow a power-law behaviour as a function of the ratio τα/τβ with a universal exponent; yet, its relative amplitude to that of the α-relaxation varies as does the temporal separation of both processes. The mean activation energy of the β-process as well as the width of the energy distribution gβ(E) increases more or less systematically with Tg. The latter is determined from the dielectric spectra subjected to a scaling procedure assuming a thermally activated process. Plotting gβ(E) as a function of the reduced energy scale E/Tg, the distributions are centred between 19-35 and their widths differ by a factor 2-3.
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Affiliation(s)
- Thomas Körber
- Department of Inorganic Chemistry III and Northern Bavarian NMR Centre, University of Bayreuth, 95440 Bayreuth, Germany.
| | - Felix Krohn
- Department of Macromolecular Chemistry and Bavarian Polymer Institute, University of Bayreuth, 95440 Bayreuth, Germany
| | - Christian Neuber
- Department of Macromolecular Chemistry and Bavarian Polymer Institute, University of Bayreuth, 95440 Bayreuth, Germany
| | - Hans-Werner Schmidt
- Department of Macromolecular Chemistry and Bavarian Polymer Institute, University of Bayreuth, 95440 Bayreuth, Germany
| | - Ernst A Rössler
- Department of Inorganic Chemistry III and Northern Bavarian NMR Centre, University of Bayreuth, 95440 Bayreuth, Germany.
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