Abstract: A compound useful as a constituent of liquid crystal materials for ferroelectric liquid crystal display elements and a liquid crystal composition containing the same are provided, which compound is expressed by the formula ##STR1## wherein R represents a linear or branched chain alkyl group or alkoxy group each of 1 to 20 carbon atoms, R* represents an optically active group of 3 to 16 carbon atoms and X and Y each represent H or F.

Abstract: A compound useful as a component constituting ferroelectric liquid crystal display elements and a liquid crystal composition containing the same are provided, which compound is expressed by the formula ##STR1## wherein R represents a linear or branched chain alkyl group of 1 to 20 carbon atoms and R* represents an optically active alkyl group, alkoxy group, alkoxyalkyl group, alkoxyalkoxy group, alkanoyloxyalkyl group, alkanoyloxyalkoxy group, halogenated alkyl group or halogenated alkoxy group each of 2 to 20 carbon atoms.

Abstract: An optically active liquid crystal compound having a large spontaneous polarization value and a chiral smectic liquid crystal composition containing the same are provided, which compound is expressed by the formula ##STR1## wherein R.sup.1 and R.sup.2 each represent an alkyl group of 4 to 18 carbon atoms and l represents 1 or 0.

Abstract: A novel liquid crystal compound exhibiting SC phase which, when added to an optically active liquid crystal, makes the resulting chiral smectic liquid crystal material exhibit superior performances in liquid crystal display elements utilizing the ferroelectricity of the material, and a chiral smectic C composition using the compound, which compound is expressed by the formula ##STR1## wherein R.sup.1 l represents an alkyl group of 7 to 12 carbon atoms and R.sup.2 represents an alkyl group of 5 to 12 carbon atoms.

Abstract: A novel liquid crystal compound represented by the general formula (I): ##STR1## (wherein R is a straight or branched alkyl or alkoxy group having 1 to 20 carbon atoms, R* is an optically active alkyl group having 4 to 20 carbon atoms, X is a fluorine atom or a chlorine atom, and n is 1 or 2), a liquid crystal composition containing at least one liquid crystal compound of the general formula (I), a chiral smectic liquid crystal composition containing at least one liquid crystal compound of the general formula (I), and an optical switching element utilizing the chiral smectic liquid crystal composition containing at least one liquid crystal compound of the general formula (I) are described.

Abstract: A ferroelectric pyridine compound suitable as a liquid crystal for display mode utilizing ferroelectric properties and exhibiting SC* phase at a temperature somewhat higher than room temperature and a liquid crystal composition are provided, which compound is expressed by the formula ##STR1## wherein n represents an integer of 0 to 8, R.sub.1 represents an alkyl group of 2 to 18 carbon atoms, R.sub.2 represents an alkyl group of 1 to 18 carbon atoms and the symbol * indicates that C having the symbol attached thereon is an optically active carbon atom.

Abstract: A novel liquid crystal compound exhibiting SC phase which, when added to an optically active liquid crystal, makes the resulting chiral smectic liquid crystal material exhibit superior performances in liquid crystal display elements utilizing the ferroelectricity of the material, and a chiral smectic C composition using the compound. The compound is expressed by the formula ##STR1## wherein X represents F or Cl and R.sub.1 and R.sub.2 each represent a straight chain alkyl group of 1 to 18 carbon atoms.

Abstract: A novel optically active liquid crystal compound and a liquid crystal composition containing the same are provided, which compound is expressed by the formula ##STR1## wherein R.sub.1 is alkyl or alkoxy of 4-18 C; R.sub.2 is alkyl, alkoxy, acyl or alkoxymethyl of 4-18 C; but either one of R.sub.1 or R.sub.2 is an optically active group; either one of X.sub.1 or X.sub.2 is halogen atom and the other is H; m and n each are 0 or 1 and m+n is 0 or 1.

Abstract: A novel liquid crystalline, halogen-containing heterocyclic compound having a characteristic that even when its S.sub.c * phase is supercooled, no other smectic phases appear, and a liquid crystal composition containing the same are provided, which compound is expressed by the formula ##STR1## wherein R.sub.1 and R.sub.2 each represent an alkyl group of 2 to 18 carbon atoms; X represents --N.dbd. or --CH.dbd.; Y represents F or Cl; n represents an integer of 0 to 10; and a symbol * represents an asymmetric carbon atom.

Abstract: A novel liquid-crystalline, optically active compound exhibiting a chiral smectic phase and a chiral smectic liquid crystal composition containing the same are provided, which liquid-crystalline, optically active compound is a compound expressed by the formula ##STR1## wherein X represents a linear chain alkyl group or a linear chain alkoxy group, each of 4 to 18 carbon atoms, or a halogen atom, R* represents an optically active alkyl group of 4 to 18 carbon atoms and ##STR2## shows that the oxygen atom can be bonded to either nitrogen atom.

Abstract: A ferroelectric liquid crystal compound having superior properties and a chiral smectic liquid crystal composition are provided. The ferroelectric liquid crystal compound is expressed by the formula ##STR1## wherein R represents an alkyl group of 2-18 C; A, --COO-- or --OCO--; l and m each, 1 or 2 but l+m=2 or 3; n, an integer of 2-8; and symbol *, an asymmetric carbon atom.

Abstract: A novel liquid crystal compound exhibiting smectic phases and useful for display elements and a chiral smectic liquid crystal composition containing the compound are provided, which compound is expressed by the formula ##STR1## wherein R.sup.1 and R.sup.2 each represent an alkyl group of 1 to 20 carbon atoms and X represents H atom or F atom, and which composition comprises at least one kind of the compounds of the formula (I) and an optically active compound.

Abstract: A novel chiral liquid crystal compound having an optically active group which affords a superior response rate when used as a liquid crystal display element, and a liquid crystal composition containing the same are provided, which chiral liquid crystal compound is expressed by the formula ##STR1## wherein R represents an alkyl group of 1 to 18 carbon atoms; R* represents an optically active alkyl group of 4 to 15 carbon atoms; X represents single bond, --O--, ##STR2## Y represents --CH.sub.2 O-- or --OCH.sub.2 --; Z represents single bond, --O--, ##STR3## and m and n each represent 1 or 2.

Abstract: Novel ferroelectric liquid crystals exhibiting a chiral smectic C phase and liquid crystal compositions containing the same are provided, which liquid crystals are substituted biphenyl esters expressed by the general formula ##STR1## wherein R.sub.1 * represents an optically active alkyl group of 4 to 18 carbon atoms; ##STR2## represents ##STR3## or ##STR4## Z represents R.sub.2, R.sub.2 CO or R.sub.2 COO wherein R.sub.2 represents an alkyl group or an alkoxy group each of 1 to 18 carbon atoms; and X and Y each represent hydrogen atom (H), bromine atom (Br), chlorine atom (Cl), fluorine atom (F) or cyano group (CN), and either one of X or Y is always hydrogen atom.

Abstract: A novel, superior, optically active liquid crystal compound exhibiting a smectic C* phase, and a liquid crystal composition containing the same are provided, which compound is expressed by the formula ##STR1## wherein X represents --CH.sub.2 O-- or --OCH.sub.2 --; Y represents --COO-- or --OCO--; and either one of R.sup.1 or R.sup.2 represents an optically active alkyl group, alkoxy group or alkoxycarbonyl group and the other represents a non-optically-active alkyl group or alkoxy group each of 4 to 18 carbon atoms.

Abstract: Compounds useful as lower viscosity liquid-crystalline components of which liquid-crystalline compositions are partly composed are provided, which compounds areliquid-crystalline compounds expressed by the general formula ##STR1## wherein ##STR2## and R.sub.1 and R.sub.2 each represent an alkyl group of 1 to 8 carbon atoms, orliquid-crystalline compounds expressed by the general formula ##STR3## wherein R.sub.1 and R.sub.2 each represent an alkyl group of 1 to 8 carbon atoms.

Abstract: A novel optically active compound suitable for use in a display mode utilizing a ferroelectric liquid crystal, and a chiral smectic liquid crystal composition containing the same are provided, which novel optically active compound is expressed by the formula ##STR1## wherein R represents an alkyl group of 2 to 15 carbon atoms; X represents CN group or a halogen atom; Y and Z each represent a halogen atom or hydrogen atom, but either one of Y and Z is hydrogen atom; l is 1 or 2; m is 0 or 1; and a symbol * shows that the carbon atom having this symbol attached thereto constitutes an optically active center.

Abstract: Chiral smectic compounds having a high response rate and being superior as a ferroelectric liquid crystalline material, and chiral smectic mixtures containing the same are provided, which compounds being expressed by the formula ##STR1## wherein X represents --CH.sub.2 --, --O-- or --CO--; n represents 0, 1 or 2; when X represents --CH.sub.2 --, Y represents R--, R--CO--, ROCO--, ##STR2## wherein R represents an alkyl group having 1 to 18 carbon atoms, and when X represents --O-- or --CO--, Y represents R; and * represents a symbol indicating an optically active carbon atom.

Abstract: A novel chiral liquid crystal compound having an optically active group which affords a superior response rate when used as a liquid crystal display element, and a liquid crystal composition containing the same are provided, which chiral liquid crystal compound is expressed by the formula ##STR1## wherein R represents an alkyl group of 1 to 18 carbon atoms; R* represents an optically active alkyl group of 4 to 15 carbon atoms; X represents single bond, --O--, ##STR2## Y represents --CH.sub.2 O-- or --OCH.sub.2 --; Z represents single bond, --O--, ##STR3## and m and n each represent 1 or 2.

Abstract: A liquid crystal compound containing an optically active group, suitable for being used for display mode utilizing ferroelectric liquid crystals, and a composition containing the same are provided, which compound is an optically active pyridazine compound expressed by the general formula ##STR1## wherein X represents an alkyl group or an alkoxy group each having 1 to 18 carbon atoms and R* represents an optically active group.