Dielectric Spectroscopy Studies of Conformational Relaxation Dynamics in Molecular Glass-Forming Liquids
We review experimental results obtained with broadband dielectric spectroscopy concerning the relaxation times and activation energies of intramolecular conformational relaxation processes in small-molecule glass-formers. Such processes are due to the interconversion between different conformers of...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-12-01
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| Series: | International Journal of Molecular Sciences |
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| Online Access: | https://www.mdpi.com/1422-0067/24/24/17189 |
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| author | Michela Romanini Roberto Macovez Sofia Valenti Wahi Noor Josep Lluís Tamarit |
| author_facet | Michela Romanini Roberto Macovez Sofia Valenti Wahi Noor Josep Lluís Tamarit |
| author_sort | Michela Romanini |
| collection | DOAJ |
| description | We review experimental results obtained with broadband dielectric spectroscopy concerning the relaxation times and activation energies of intramolecular conformational relaxation processes in small-molecule glass-formers. Such processes are due to the interconversion between different conformers of relatively flexible molecules, and generally involve conformational changes of flexible chain or ring moieties, or else the rigid rotation of planar groups, such as conjugated phenyl rings. Comparative analysis of molecules possessing the same (type of) functional group is carried out in order to test the possibility of assigning the dynamic conformational isomerism of given families of organic compounds to the motion of specific molecular subunits. These range from terminal halomethyl and acetyl/acetoxy groups to both rigid and flexible ring structures, such as the planar halobenzene cycles or the buckled saccharide and diazepine rings. A short section on polyesters provides a generalisation of these findings to synthetic macromolecules. |
| first_indexed | 2024-03-08T20:41:30Z |
| format | Article |
| id | doaj.art-1743435e18b94a74b962caa9fb824b29 |
| institution | Directory Open Access Journal |
| issn | 1661-6596 1422-0067 |
| language | English |
| last_indexed | 2024-03-08T20:41:30Z |
| publishDate | 2023-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | International Journal of Molecular Sciences |
| spelling | doaj.art-1743435e18b94a74b962caa9fb824b292023-12-22T14:13:32ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672023-12-0124241718910.3390/ijms242417189Dielectric Spectroscopy Studies of Conformational Relaxation Dynamics in Molecular Glass-Forming LiquidsMichela Romanini0Roberto Macovez1Sofia Valenti2Wahi Noor3Josep Lluís Tamarit4Grup de Caracterització de Materials, Departament de Física and Barcelona Research Center in Multiscale Science and Engineering, Universitat Politècnica de Catalunya, Barcelona East School of Engineering (EEBE), Av. Eduard Maristany 10-14, E-08019 Barcelona, SpainGrup de Caracterització de Materials, Departament de Física and Barcelona Research Center in Multiscale Science and Engineering, Universitat Politècnica de Catalunya, Barcelona East School of Engineering (EEBE), Av. Eduard Maristany 10-14, E-08019 Barcelona, SpainGrup de Caracterització de Materials, Departament de Física and Barcelona Research Center in Multiscale Science and Engineering, Universitat Politècnica de Catalunya, Barcelona East School of Engineering (EEBE), Av. Eduard Maristany 10-14, E-08019 Barcelona, SpainGrup de Caracterització de Materials, Departament de Física and Barcelona Research Center in Multiscale Science and Engineering, Universitat Politècnica de Catalunya, Barcelona East School of Engineering (EEBE), Av. Eduard Maristany 10-14, E-08019 Barcelona, SpainGrup de Caracterització de Materials, Departament de Física and Barcelona Research Center in Multiscale Science and Engineering, Universitat Politècnica de Catalunya, Barcelona East School of Engineering (EEBE), Av. Eduard Maristany 10-14, E-08019 Barcelona, SpainWe review experimental results obtained with broadband dielectric spectroscopy concerning the relaxation times and activation energies of intramolecular conformational relaxation processes in small-molecule glass-formers. Such processes are due to the interconversion between different conformers of relatively flexible molecules, and generally involve conformational changes of flexible chain or ring moieties, or else the rigid rotation of planar groups, such as conjugated phenyl rings. Comparative analysis of molecules possessing the same (type of) functional group is carried out in order to test the possibility of assigning the dynamic conformational isomerism of given families of organic compounds to the motion of specific molecular subunits. These range from terminal halomethyl and acetyl/acetoxy groups to both rigid and flexible ring structures, such as the planar halobenzene cycles or the buckled saccharide and diazepine rings. A short section on polyesters provides a generalisation of these findings to synthetic macromolecules.https://www.mdpi.com/1422-0067/24/24/17189molecular conformerssecondary relaxationsactivation barriercharacteristic relaxation timeinternal rotationring buckling |
| spellingShingle | Michela Romanini Roberto Macovez Sofia Valenti Wahi Noor Josep Lluís Tamarit Dielectric Spectroscopy Studies of Conformational Relaxation Dynamics in Molecular Glass-Forming Liquids International Journal of Molecular Sciences molecular conformers secondary relaxations activation barrier characteristic relaxation time internal rotation ring buckling |
| title | Dielectric Spectroscopy Studies of Conformational Relaxation Dynamics in Molecular Glass-Forming Liquids |
| title_full | Dielectric Spectroscopy Studies of Conformational Relaxation Dynamics in Molecular Glass-Forming Liquids |
| title_fullStr | Dielectric Spectroscopy Studies of Conformational Relaxation Dynamics in Molecular Glass-Forming Liquids |
| title_full_unstemmed | Dielectric Spectroscopy Studies of Conformational Relaxation Dynamics in Molecular Glass-Forming Liquids |
| title_short | Dielectric Spectroscopy Studies of Conformational Relaxation Dynamics in Molecular Glass-Forming Liquids |
| title_sort | dielectric spectroscopy studies of conformational relaxation dynamics in molecular glass forming liquids |
| topic | molecular conformers secondary relaxations activation barrier characteristic relaxation time internal rotation ring buckling |
| url | https://www.mdpi.com/1422-0067/24/24/17189 |
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