Temperature Dependence of Physical Constants with Varied Molecular Length and Position of Fluorine Substituents in Phenyl-bicyclohexane Core Liquid Crystals

The effects of a fluorinated substituent on physical properties of phenyl bicyclohexane liquid crystals (LCs) are reported. Temperature dependence of the physical properties for different terminals and extents of fluorine substituents were compared. Electro optic measurements suggest that the molecular length and position of fluorine strongly influence the threshold voltage and anisotropic dielectric constant. However, the resulting temperature dependences of refractive indices, order parameters and splay elastic constants indicate that the fluorine substituents cause minor differences. The effect of symmetric fluorine substituents on the benzene ring was also discussed.