New method and results of Raman studies of non-diffusional reorientational dynamics of molecules in the nematic phase
| Autor: | S. Ye. Yakovenko, B. Arnscheidt, Josef Pelzl, Anatoli A. Minko |
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| Rok vydání: | 1995 |
| Předmět: |
Materials science
Cyclohexane Relaxation (NMR) Rotation around a fixed axis General Chemistry Condensed Matter Physics Molecular physics chemistry.chemical_compound symbols.namesake Nuclear magnetic resonance chemistry Liquid crystal Intramolecular force Phase (matter) symbols General Materials Science Coherent anti-Stokes Raman spectroscopy Raman spectroscopy |
| Zdroj: | Liquid Crystals. 19:449-458 |
| ISSN: | 1366-5855 0267-8292 |
| Popis: | The method of differential Raman spectroscopy is developed to the case of uniaxial liquid crystals, increasing the precision of the determination of relative broadening and splitting of the polarized components of Raman bands in liquid crystals. With the help of the new technique and on the basis of a more general treatment of rotational broadening of Raman bands, some typical liquid crystal materials, namely, 4-pentyl-4′-cyanobiphenyl (5CB) and trans-4-pentyl-(4-cyanophenyl)cyclohexane (5PCH) have been studied. It is shown that for a particular form of intramolecular vibration (for example the cyano stretching mode), it is possible to determine all independent orientational autocorrelation functions without applying model considerations of the rotational motion in the nematic phase. The deviations of the results of these studies from a simple diffusional model of orientational relaxation in the short-time limit are discussed. |
| Databáze: | OpenAIRE |
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