Abstract: A ferroelectric chiral smectic liquid crystal composition, comprising at least one optically active compound represented by the following formula (I): ##STR1## wherein R.sub.1 denotes a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent; R.sub.2 denotes a linear or branched alkyl group having 1-14 carbon atoms capable of having a substituent; and X.sub.1 denotes a single bond, ##STR2## and at least one optically active compound represented by the following formula (II): ##STR3## wherein R.sub.3 denotes a linear alkyl group having 1-14 carbon atoms; R.sub.4 denotes a linear or branched alkyl group having 1-14 carbon atoms capable of having a substituent; and X.sub.

Abstract: An optically active mesomorphic compound represented by the formula (III) is obtained through an optically active compound represented by the formula (I) and then through a compound represented by the formula (II), respectively, shown below. ##STR1## In the above formulas, R represents a linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1-18 carbon atoms each capable of having a substituent, C* represents an asymmetric carbon atom, k is an integer of from 2 to 5, A is a releasable active group such as hydroxyl, l is 0 or 1, and when l is 1, m is 0, 1 or 2 and n is 0 or 1; R.sup.1 represents an alkyl or alkoxy group having 1-18 carbon atoms; ##STR2## respectively denote ##STR3## p, q and r are respectively 0 or 1 satisfying the relation of p+q+r.gtoreq.1.

Abstract: A liquid crystal composition comprises at least one compound represented by the formula [I] below and at least one compound represented by the formula [II] below: ##STR1## wherein R.sub.1 denotes an alkyl group having 1-16 carbon atoms capable of having a substituent; R.sub.2 denotes any one of alkyl group, alkoxy group, alkoxycarbonyl group, acyloxy group and alkoxycarbonyloxy group, each having 1-16 carbon atoms and being capable of having a substituent; and A denotes any one of ##STR2## each capable of having a substituent; and ##STR3## wherein R.sub.3 denotes a linear alkyl group having 1-16 carbon atoms; R.sub.4 denotes a linear alkyl group having 1-12 carbon atoms; X.sub.1 is a single bond, --O--, ##STR4## X.sub.2 is --OCH.sub.2 --, ##STR5## or --CH.sub.

Abstract: A mesomorphic compound represented by the following formula (I): ##STR1## wherein R.sub.1 and R.sub.2 respectively denote a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent; X denotes any one of a single bond, --O--, ##STR2## Y denotes ##STR3## or --CH.sub.2 O--; and Z denotes any one of --O--, ##STR4## .

Abstract: A mesomorphic compound represented by the following formula (I): ##STR1## wherein R.sub.1 and R.sub.2 respectively denote a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent; X.sub.1 denotes any one of a single bond, --O--, ##STR2## X.sub.2 denotes any one of a single bond, --O--, ##STR3## Z.sub.1 denotes any one of ##STR4## --CH.sub.2 O-- and --CH.dbd.C(CN)--; and A.sub.1 denotes --A.sub.2 -- or --A.sub.2 --A.sub.3 -- wherein A.sub.2 and A.sub.

Abstract: There is provided a liquid crystal compound represented by the following general formula (I), a liquid crystal composite including at least one kind of above liquid crystal compound and a liquid crystal device in which the liquid crystal composite is disposed between a pair of electrode substrates. ##STR1## In the above formula (I), R.sub.1 is a straight chain alkyl having 1-12 carbon atoms. R.sub.2 is a straight chain or branched chain alkyl, which may have a substituted radical, having 1-18 carbon atoms and in which one or more than two methylene, which do not adjoin, may be substituted by --Y--, ##STR2## --CH.dbd.CH--, or --C.vertline.C--. Y is O or S. A is --A.sub.1 -- or --A.sub.1 --A.sub.2 --, and B is --B.sub.1 -- or --B.sub.1 --B.sub.2 --. A.sub.1, A.sub.2, B.sub.1, and B.sub.2 each is selected from ##STR3## and a single bond. Z is hydrogen, halogen, cyano or methyl. X.sub.1 is a single bond when A is a single bond and is --CH.sub.2 O--, ##STR4## in other cases. n is 0 or 1, ##STR5## --OCH.sub.

Abstract: A mesomorphic compound represented by the following formula (I): ##STR1## wherein R.sub.1 and R.sub.2 respectively denote an alkyl group having 1-16 carbon atoms capable of having a substituent; X.sub.1, X.sub.2 and X.sub.3 respectively denote a single bond, --O--, ##STR2## A.sub.1 and A.sub.2 respectively ##STR3## wherein X.sub.4 and X.sub.5 respectively denote hydrogen, fluorine, chlorine, bromine, --CH.sub.3, --CN or --CF.sub.3 with proviso that X.sub.1 always denotes a single bond when A.sub.1 denotes a single bond; and n is 0 or 1.

Abstract: A mesomorphic compound represented by the following formula (I): ##STR1## wherein R.sup.1 and R.sup.2 respectively denote a linear or branched alkyl group having 1-18 carbon atoms capable of including one or two or more non-neighboring methylene groups which can be replaced with at least one species of --Z--, ##STR2## --CH.dbd.CH-- and --C.tbd.C--, wherein Z denotes --O-- or --S-- and R.sup.3 denotes hydrogen or an alkyl group having 1-5 carbon atoms; A.sup.1 denotes ##STR3## and A.sup.2 denotes any one of ##STR4## The mesomorphic compound is effective for providing a ferroelectric liquid crystal composition showing an improved low-temperature operation characteristic and a decreased temperature-dependence of response speed.

Abstract: A liquid crystal composition, comprising: at least one compound represented by the following formula (I): ##STR1## wherein R.sub.1 and R.sub.2 respectively denote an optically inactive linear or branched alkyl group having 1-18 carbon atoms capable of including one or non-neighboring two or more methylene groups which can be replaced with at least one species of ##STR2## wherein Z denotes --O-- or --S-- and R.sub.3 denotes hydrogen or an alkyl group having 1-5 carbon atoms; A denotes --A.sub.1 -- or --A.sub.2 --A.sub.3 -- wherein A.sub.1 denotes ##STR3## and A.sub.2 and A.sub.3 respectively denote ##STR4## or --A.sub.1 --; and at least one compound represented by the following formula (II): ##STR5## wherein R.sub.4 denotes a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent; X.sub.1 denotes a single bond, --O--, ##STR6## X.sub.2 denotes a single bond, --O-- or ##STR7## Z.sub.1 denotes a single bond or ##STR8## A.sub.4 denotes ##STR9## and l is 1-12.