Abstract: Liquid crystalline ferroelectric derivatives of branched acyclic alpha-chlorocarboxylic acids of the general formula I ##STR1## wherein n=0 or 1; m=0 or 1, o=0 or 1; p=0 or 1X=--COO--, --OOC--, or --CH.sub.2 --CH.sub.2 --Y=X, --CH.sub.2 --, --N.dbd.N--, or --N.dbd.N(O)--, ##STR2## It was discovered that, by reacting chiral alpha-chlorocarboxylic acids or alpha-chlorocarboxylic acid chlorides or bromides, synthesized from natural alpha-amino acids by reaction with nitric and hydrochloric acids, with appropriate hydroxy compounds directly or in the presence of strongly dehydrating substances, preferably carbodiimides, liquid crystalline ferroelectric substances of the general formula I are formed.The inventive substances by themselves, in mixtures with one another as well as with other liquid crystalline substances or substances which are not liquid crystalline, can form liquid crystalline ferroelectric phases, which make them suitable for use in displays.

Abstract: 2,5-substituted 1,3,4-thiadiazoles of the general formula ##STR1##The aforementioned compounds are used in amounts of 0.1 to 80 mole percent in mixtures for electrooptical arrangements for the modulation of transmitted and reflected light, as well as for the colored or black-and-white display of numerals, symbols and moving or still pictures. The compounds endow the liquid-crystalline mixtures with an extended phase field of the smectic C phase, negative dielectric anisotropy and the property of forming optically active C phases upon admixture with optically active compounds.

Abstract: Fast-switching displays with memory properties are provided, which can display digits, symbols, and images, and which contain as chemically and thermally stable ferroelectric liquid crystalline substances, according to the invention, liquid crystalline derivatives which contain a chiral alkyl halide residue corresponding to the general formula ##STR1## are used in mixtures of one another as well as in conjunction with other liquid crystalline or non-crystalline liquid substances.

Abstract: The orientation of a thermotropic LC volume is achieved by means of thermotropic LC molecules firmly bonded chemically to a matrix. The orientation takes place due to the physical and chemical properties of the LC volume, chemically bonded to the matrix on the disordered LC volume. Hydrocarbon polymers or organosilanes are used as the matrix, to the functional groups of which the thermotropic liquid crystal molecules, which also have functional groups suitable for bonding to the matrix, are chemically linked. The chemically linked thermotropic LC may be a nematic, cholesterinic, discotic or smectic LC, with which nematic, cholesterinic, discotic or smectic LC volumes can be oriented. The matrix is chemically bonded covalently to the substrate surface and may be colored due to additional coupling of reactive dyes.

Abstract: Compounds of the general formula C.sub.m H.sub.2m+2, wherein m signifies 10 to 35, are added to liquid crystalline nematic substances to shorten the switching time of the substances when used in opto-electronic components.

Abstract: Liquid crystalline 2,6-disubstituted trans-1,3-dioxadecalins of the general formula ##STR1## are well suited as components of low double refraction for mixtures which are utilized in opto-electronic components.

Abstract: A mixing component for nematic liquid-crystalline substances used in optoelectronic components for the rendition of numbers, symbols and images. The object of the invention is to reduce, in components for nematic liquid crystal substances, the threshold and operating voltages. It has been found, that the addition of one or more 1-oxa-2,6,7-trioxane-1-phospha-bicyclo-derivatives having the general formula ##STR1## wherein ##STR2## with R.sup.1 =C.sub.n H.sub.2n+1 --, C.sub.n H.sub.2n+1 O--, C.sub.n H.sub.2n+1 COO--, C.sub.n H.sub.2n+1 OCOO--, R.sup.2 +C.sub.n H.sub.2n=1 --with n=an integer from 1 to 10to nematic liquid crystal substances, considerably reduces the operating voltage.

Abstract: 2-Substituted-5-(1-alkyl-piperid-yl)-1,3-dioxanes of the formula I ##STR1## wherein R= ##STR2## R.sup.1 =--C.sub.n H.sub.2n+1, --OC.sub.n H.sub.2n+1, --OOCC.sub.n H.sub.2n+1, --COC.sub.n H.sub.2n+1, --OOCOC.sub.n H.sub.2n+1, --F, --Cl, --Br, --I, --NO.sub.2, --CN --(CH.sub.2).sub.2 CN, ##STR3## and n=1 to 10, are novel liquid crystalline compounds, which can be produced in high yields by means of reacting 2-(1-alkyl-piperid-4-yl)-propane-1,3-diols with aldehydes in the presence of acid catalysts, such as p-toluenesulfonic acid, mineral acids and Lewis acids. Because of their high thermal and chemical stability, which is also transferred to mixtures, the compounds of the formula I are very well suited for utilization in optoelectronic displays.