A liquid crystal compound represented by formula (I) and a liquid crystal composition containing the same. The compound exhibits an antiferroelectric liquid crystal phase and has good compatibility with known liquid crystal compounds. ##STR1## wherein R.sup.1 represents a straight-chain or branched alkyl, alkoxy, alkoxycarbonyl, alkanoyloxy or alkoxycarbonyloxy group having 4 to 16 carbon atoms; R.sup.2 represents a straight-chain alkyl group having 4 to 10 carbon atoms or a branched alkyl group containing 1 to 3 carbon atoms in its branch and 4 to 12 carbon atoms in total; X represents an oxygen or sulfur atom; rings A and B each represent an F-substituted or unsubstituted phenylene group, a cyclohexylene group or a divalent nitrogen-containing heterocyclic group, provided that either one of rings A and B is the nitrogen-containing heterocyclic group; ring C represents an F-substituted or unsubstituted phenylene group; and C* represents an asymmetric carbon atom.
化学式(I)表示的液晶化合物和含有该化合物的液晶组合物。该化合物表现出反
铁电液晶相,并且与已知液晶化合物具有良好的相容性。其中,R.sup.1代表具有4到16个碳原子的直链或支链烷基,烷氧基,烷氧羰基,烷酰氧基或烷氧羰氧基;R.sup.2代表具有4到10个碳原子的直链烷基或含有1到3个碳原子的支链烷基,并且总共含有4到12个碳原子;X代表氧原子或
硫原子;环A和环B分别表示F取代或未取代的苯基,环己基或含氮杂环基,其中环A和环B中的任意一个是含氮杂环基;环C表示F取代或未取代的苯基;C*表示一个不对称的碳原子。