Orientational order parameter in five fluorinated nematogens have been investigated by means of optical, dielectric and 19F NMR techniques. Quantum mechanical calculations were also employed to derive molecular and nuclear properties necessary for the analysis of the spectroscopic quantities. The obtained data were compared and discussed taking into account the differences among the three methods. The values of the order parameter differ due to different anisotropic physical quantities measured and, consequently, the different axes frame in which the order parameters are defined. However, the temperature trends, expressed with the aid of the Haller-type relation, are very close within the broad range of the nematic phase. Copyright © Taylor & Francis Group, LLC.
Determination of order parameters in laterally fluorosubstituted terphenyls by 19F-NMR, optical and dielectric anisotropies
Marini, Alberto;
2011-01-01
Abstract
Orientational order parameter in five fluorinated nematogens have been investigated by means of optical, dielectric and 19F NMR techniques. Quantum mechanical calculations were also employed to derive molecular and nuclear properties necessary for the analysis of the spectroscopic quantities. The obtained data were compared and discussed taking into account the differences among the three methods. The values of the order parameter differ due to different anisotropic physical quantities measured and, consequently, the different axes frame in which the order parameters are defined. However, the temperature trends, expressed with the aid of the Haller-type relation, are very close within the broad range of the nematic phase. Copyright © Taylor & Francis Group, LLC.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
