Abstract: An optically active compound represent by formula (I): ##STR1## wherein R.sub.1 represents a fluoroalkyl group having from 1 to 18 carbon atoms; R.sub.2 represents an alkyl group having from 1 to 16 carbon atoms and an aralkyl group having from 6 to 16 carbon atoms; R.sub.3 represents C.sub.2 F.sub.5, CF.sub.3, CHF.sub.2, or CH.sub.2 F; X represents a single bond, --O--, --COO--, or --OCO--; Y represents --COO--, --OCO--, --CH.sub.2 O--, or --OCH.sub.2 --; Z represents --COO-- or --O--; (A) and (B) each represent a cyclic group; and * indicates an optically active center, and a liquid crystal composition containing at least one of said optically active compounds are disclosed. The compound is useful not only as a liquid crystal compound but as a chiral dopant to provide a liquid crystal composition exhibiting a chiral smectic phase.

Abstract: A liquid crystal compound represented by formula (I): ##STR1## wherein R.sub.1 represents an alkyl group having from 3 to 18 carbon atoms or an aralkyl group having from 7 to 18 carbon atoms; R.sub.2 represents an alkenyl group having from 1 to 18 (preferably from 3 to 14) carbon atoms; R.sub.3 represents CF.sub.3 or C.sub.2 F.sub.5 ; X represents a single bond, --O--, --COO--, or --OCO--; Y represents --COO--, --OCO--, --CH.sub.2 O--, or --OCH.sub.2 --; A and B each represents a cyclic group; and * indicates an optically active center.The compound of formula (I) exhibits three stable states of molecular orientation.

Abstract: The invention lies in novel ferroelectric liquid crystal compounds particularly represented by the general formulae, having a good responsibility in relation to the applied electric field and a wide range of phase transition points inclusive of the room temperature so as to be useful alone as the liquid crystal material but also to be mixed with other liquid crystal compounds for expanding the phase transition points to a desired range and making the response speed of the liquid crystal composition faster. ##STR1## In the formulae, m and n are same or different with each other and represent an integral of 1-20.

Abstract: There is disclosed herein a ferroelectric liquid crystal electro-optical apparatus of the maxtrix type comprising a liquid crystal cell having first and second electrode substrates which include n striped line electrodes and m striped column electrodes, respectively, facing at right angles each other. A ferroelectric liquid crystal is put in therebetween so as to form n by m indication picture elements. Also included in the apparatus a scanning drive device adapted to supply a scanning signal and a data signal to the n striped line electrodes and the m striped column electrodes, respectively. The ferroelectric liquid crystal shows three stable states in accordance with an application voltage and has a light transmittance with a hysteresis sufficient to a dynamic drive in accordance with increase or decrease in the application voltage in a predetermined voltage range.

Abstract: The invention intends to separating a methyl derivative of naphthalene (2,6-dimethyl naphthalene or 2-methyl naphthalene) from a mixture material in a high purity more than 98 weight %. The starting material is preliminarily treated at a raised temperature up to 220.degree. c. at the highest and with LHSV of 0.1-6 Hr.sup.-1 in the presence of an acid catalyst usually used for olefin polymerization. The treated material is distillated to remove the polymerized impurities and to raise the naphthalene derivative content at least up to 50 weight %. And then the obtained material is subjected to the crystallization under a pressure of 500-2500 kgf/cm.sup.2 at a temperature of 80.degree.-150.degree. C. (for 2,6-DMN) or 10.degree.-35.degree. C. (for 2-MN).

Abstract: Novel ferroelectric liquid crystal compounds which may realize a stable molecular orientation which makes it possible to give a definite light-dark contrast in the no electric field state and attain a definite threshold property as well as hysteresis, and for making it possible to attain the dynamic driving as well as the high speed of response, owing to tri-stable phase thereof, of the general formulae (I) and (II) ##STR1## in which R.sub.1 means an alkyl, alkoxy or alkyloxycarbonyl each of 1-20 carbon atoms, R.sub.