Chiral esters of alpha -substituted carboxylic acids and mesogenic phenols, and their use as dopants in liquid-crystal phases

摘要

The novel compounds are chiral esters of alpha -substituted carboxylic acids and mesogenic phenols which are characterised by the formula (I) <IMAGE> in which the symbols have the following meanings: R<1> is straight-chain or branched (C3-C12)alkyl, in which one or two non-adjacent CH2 groups may be replaced by O and/or S atoms, A is diazine-2,5-diyl, Y is F, Cl, Br, CN or CF3, and R<2> is straight-chain (C1-C9)alkyl or branched (C3-C9)alkyl. The compounds are preferably used in tilted, smectic liquid-crystal phases which they convert into ferroelectric liquid-crystal phases; they have or induce high values for spontaneous polarisation.