A liquid-crystalline medium which comprises at least one compound selected from the group of compounds of the formulae IA to IH, ##STR00001##
in which Z.sup.1 denotes a single bond, CH.sub.2CH.sub.2, CH?CH, CH.sub.2O, OCH.sub.2, CF.sub.2O, OCF.sub.2, COO, OCO, C.sub.2F.sub.4, (CH.sub.2).sub.4, CHFCHF, CF.sub.2CH.sub.2, CH.sub.2CF.sub.2, C?C, CF?CF, CH?CHCHO or CH.sub.2CF.sub.2O,
and the use thereof for an active-matrix display, in particular based on the VA, PSA, PS-VA, PALC, FFS, PS-FFS, SA-VA, PS-IPS or IPS effect.

The invention relates to a compound of formula I, ##STR00001##
wherein R.sup.11, R.sup.21, A.sup.11, A, Z, X.sup.11, X.sup.21, Y.sup.11, Y.sup.12, Sp.sup.11, Sp.sup.21, o and p have one of the meanings as given in claim 1. The invention further relates to method of production of a compound of formula I, to the use of said compounds in LC media and to LC media comprising one or more compounds of formula I. Further, the invention relates to a method of production of such LC media, to the use of such media in LC devices, and to LC device comprising a LC medium according to the present invention. The present invention further relates to a process for the fabrication such liquid crystal display and to the use of the liquid crystal mixtures according to the invention for the fabrication of such liquid crystal display.

A liquid-crystalline medium which comprises at least one compound selected from the group of compounds of the formulae IA to IH, ##STR00001##
in which Z.sup.1 denotes a single bond, CH.sub.2CH.sub.2, CH?CH, CH.sub.2O, OCH.sub.2, CF.sub.2O, OCF.sub.2, COO, OCO, C.sub.2F.sub.4, (CH.sub.2).sub.4, CHFCHF, CF.sub.2CH.sub.2, CH.sub.2CF.sub.2, C?C, CF?CF, CH?CHCHO or CH.sub.2CF.sub.2O,
and the use thereof for an active-matrix display, in particular based on the VA, PSA, PS-VA, PALC, FFS, PS-FFS, SA-VA, PS-IPS or IPS effect.

The present invention relates to liquid-crystal (LC) media as defined in claim 1, to the use thereof for optical, electro-optical and electronic purposes, in particular in LC displays, and to LC displays containing said LC media. The invention in particular relates to LC media with improved response time that enable energy saving displays.

The invention relates to a compound of formula I, ##STR00001##
wherein R.sup.11, R.sup.21, A.sup.11, A, Z, X.sup.11, X.sup.21, Y.sup.11, Y.sup.12, Sp.sup.11, Sp.sup.21, o and p have one of the meanings as given in claim 1. The invention further relates to method of production of a compound of formula I, to the use of said compounds in LC media and to LC media comprising one or more compounds of formula I. Further, the invention relates to a method of production of such LC media, to the use of such media in LC devices, and to LC device comprising a LC medium according to the present invention. The present invention further relates to a process for the fabrication such liquid crystal display and to the use of the liquid crystal mixtures according to the invention for the fabrication of such liquid crystal display.

The present invention relates to a liquid-crystal (LC) medium comprising polymerizable compounds, to its use for optical, electro-optical and electronic purposes, in particular in LC displays, especially in LC displays of the PSA (polymer sustained alignment) or SA (self-aligning) mode, to an LC display of the PSA or SA mode comprising the LC medium, and to a process of manufacturing the LC display.

The new media exhibit a ferroelectric nematic phase preferably at ambient temperature. They preferably comprise one or more compounds selected from the group of compounds of formulae IA, IB and IC,

##STR00001##

in which the variable groups have the meanings indicated in the text and in the claims. Use of the media for providing ferroelectric nematic materials and a method of operation of an electro-optical device are presented. The media may be useful for energy-saving displays and electrical appliances.

The present invention relates to a negative dielectric anisotropic liquid crystal composition, a liquid crystal display element, and a liquid crystal display. The negative dielectric anisotropic liquid crystal composition of the present invention comprises a first component composed of one or more compounds represented by formula I and a second component composed of one or more polymerizable compounds: The negative dielectric anisotropic liquid crystal composition disclosed by the present invention has a low rotary viscosity, a fast response speed and a good stability, and is very suitable for manufacturing liquid crystal display elements, particularly suitable for PS (polymer-stabilized) or PSA (polymer-stabilized alignment)-type liquid crystal displays.

##STR00001##

Disclosed are compounds of the formula I, liquid-crystalline media comprising the compounds of formula I, and the use of these liquid-crystalline media in liquid-crystal displays.

Liquid-crystalline medium contains at least one compound of formula I,

##STR00001##

and at least one compound formulae ST-1 to ST-17 and the use thereof for an active-matrix display, in particular based on the VA, PSA, PA-VA, SS-VA, SA-VA, PS-VA, PALC, IPS, PS-IPS, UB-FFS, U-IPS, FFS or PS-FFS effect.