Liquid crystalline compound and liquid crystal

Abstract

A liquid crystalline compound expressed by the formula ##STR1## wherein R.sub.1 represents an alkyl group of 1 to 12 carbon atoms, and one or two not adjacent CH.sub.2 group excluding the terminal in this group may be replaced by --CO-- group, --OCO-- group, --COO-- group or --CH.dbd.CH group; X and Z each represents H, F or Cl; Y represents perfluoroalkyl group or perfluoroalkyloxy group of 1 to 4 carbon atoms, and one or two F atoms in this group may be replaced by H; one of A, B and C represents cyclohexene ring and the others thereof are chosen from among covalent bond or cyclohexane group and benzene ring and these rings may be substituted by F or Cl; and l, m and n each are 0 or 1, independently of each other, but when m=0, then l=0. Effectiveness It is possible to provide a liquid crystal composition having a large .DELTA.n, a low viscosity and a high voltage-holding ratio, and exhibiting a nematic liquid crystal phase within a broad temperature range and having a very high .DELTA..epsilon. and a low driving voltage, and preferably used for TFT. Further it is possible to provide a novel liquid crystalline compound preferred as a component for the liquid crystal composition.

Dependencies are inferred from the claim text.