Four three-ring compounds, consisting of two cyclohexyl rings and one mono- or difluorinated phenyl ring, were studied using dielectric spectroscopy methods over a broad frequency range (1kHz–3GHz). They exhibit a nematic phase in a broad temperature interval, enriched by a smectic B phase in one case. The static and dynamic dielectric properties were analysed. It was established that the bridging CH2CH2 group placed between cyclohexyl and phenyl rings considerably changes the reference frame of the molecule, unlike the situation when it links two cyclohexyl rings. In the nematic and smectic B phases the motion around the short axis is a Debye process, whereas the rotation around the long axis is split into two processes: independent rotation of the whole molecule and its fluorophenyl part.
|Autori:||Czub J; Urban S; Geppi M; Marini A; Dabrowski R|
|Titolo:||Dielectric properties of three-ring fluorinated compounds|
|Anno del prodotto:||2008|
|Digital Object Identifier (DOI):||10.1080/02678290801989983|
|Appare nelle tipologie:||1.1 Articolo in rivista|