Tricyclic Smectic C Compounds Incorporating a 1,3-Dioxan Ring

Abstract

About 80 mesogenic achiral 1,3-dioxans substituted in the 2 position by a p-(benzoyloxy)phenyl, 4-biphenylyl, 2-phenyl-5-pyridyl, or a 2-phenyl-5-pyrimidyl core have been synthesized. Most of them exhibit broad smectic C temperature ranges at elevated temperatures. The influence of the aromatic moiety, of a lateral fluorine atom and of an alkyl vs. an alkoxy side chain on the smectic C temperature range and, in some cases, on the viscosity behaviour and the thermal stability of the smectic C* phase in a ferroelectric liquid crystal mixture is studied. Many of the tricyclic 1,3-dioxans are well suited for the use in low viscosity wide-range ferroelectric smectic C* materials.

Key Words:

• smectic C
• 1,3-dioxan