| Autor: |
Ludwig, R., Bopp, Ph. A., Zeidler, M. D. |
| Zdroj: |
Zeitschrift für Naturforschung A; March 1995, Vol. 50 Issue: 2-3 p211-216, 6p |
| Abstrakt: |
Nuclear magnetic resonance (NMR) relaxation time measurements on isotopically substituted samples yield a detailed understanding of the molecular reorientational dynamics in liquids. Reorientational correlation times obtained from such experiments are reported for two molecule-fixed vectors in pure liquid methanol. While the reorientational motions of single molecules are nearly isotropic at temperatures below 250 K, at 308 K the reorientational correlation time of the O-H vector becomes 2.3 times larger than that of the O-C vector. Molecular dynamics (MD) simulations give access to the complete correlation functions of the reorientational motions. Correlation times extracted from these functions fit well to the experiment in case of the O-C vector. At low temperatures, however, these times lie markedly above those obtained in the experiment for the O-H vector. Thus, the simulation yields reorientation times for the O-H vector that are, independent of the temperature, twice as large as those of the O-C vector. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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