| Autor: |
Kossack, Wilhelm, Kipnusu, Wycliffe Kiprop, Dulski, Mateusz, Adrjanowicz, Karolina, Madejczyk, Olga, Kaminska, Ewa, Mapesa, Emmanuel Urandu, Tress, Martin, Kaminski, Kamil, Kremer, Friedrich |
| Jazyk: |
angličtina |
| Rok vydání: |
2014 |
| Předmět: |
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| Druh dokumentu: |
Článek |
| Popis: |
Fourier Transform Infrared Spectroscopy and Broadband Dielectric Spectroscopy are combined to trace kinetics of mutarotation in L-fucose. After quenching molten samples down to temperatures between T=313 K and 328 K, the concentrations of two anomeric species change according to a simple exponential time dependence, as seen by an increase in absorbance of specific IR-vibrations. In contrast, the dielectric spectra reveal a slowing down of the structural (α-) relaxation process according to a stretched exponential time dependence (stretching exponent of 1.5 ± 0.2). The rates of change in the IR absorption for α- and β-fucopyranose are (at T = 313 K) nearly one decade faster than that of the intermolecular interactions as measured by the shift of the α-relaxation. This reflects the fact that the α-relaxation monitors the equilibration at a mesoscopic length scale, resulting from fluctuations in the anomeric composition. |
| Databáze: |
Networked Digital Library of Theses & Dissertations |
| Externí odkaz: |
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