LIQUID-CRYSTALLINE PHENYLPYRIMIDINYL CYCLOHEXANECARBOXYLATES HAVING A SMECTIC PHASE, A PROCESS FOR THEIR PREPARATION, AND THEIR USE IN LIQUID-CRYSTAL MIXTURES

摘要

of the disclosure Liquid-crystalline phenylpyrimidinyl cyclohexanecarboxylates having a smectic phase, a process for their preparation, and their use in liquid-crystal mixtures The phenylpyrimidinyl trans-cyclohexanecarboxylates of the general formula <IMG> form a smectic C phase besides a relatively broad nematic phase when R1 denotes an alkyl radical having 10 to 16 carbon atoms, in particular 11 to 16 carbon atoms, or an alkoxy radical having 8 to 14 carbon atoms, and R2 denotes an alkyl radical having 2 to 9 carbon atoms. They are therefore particularly suitable as components of liquidcrystalline mixtures having a smectic C phase since they induce a relatively broad nematic phase or extend a narrow nematic phase which is present and extend the temperature range of the smectic C phase to low temperatures, but in particular to high temperatures.