There is provided a ferroelectric liquid crystal (FLC) material for the deformed helix FLC (DHFLC) electro-optical mode devices and shows optimum electro-optical properties including high tilt angle (>38°), and short helix pitch (<120 nm), and spontaneous polarization (>100 nC/cm.sup.2) comprising at least two components, wherein at least one FLC component is a chiral compound of Formula (I):

##STR00001##

particularly:

##STR00002##

wherein W.sub.1 and W.sub.2 are chiral groups with polar substituent at chiral centre, A and B are independently N atom or CH groups providing that at least one of A or B is N atom. Other various groups are as defined herein.

A material used in an element for phase control of an electromagnetic wave signal having a frequency of 1 GHz to 10 THz. A liquid crystal composition containing at least one compound selected from a group of compounds represented by Formula (1), at least one compound selected from a group of compounds represented by Formula (2) and at least one compound selected from a group of compounds represented by Formula (3).

##STR00001##

For example, R.sup.1, R.sup.21, R.sup.22, R.sup.31, and R.sup.32 are alkyls having 1 to 12 carbon atoms; a ring A.sup.1 is 1,4-phenylene; Z.sup.11, Z.sup.13, Z.sup.21, Z.sup.23, Z.sup.31, and Z.sup.33 are single bonds; Z.sup.12, Z.sup.22, and Z.sup.32 are —C≡C— or —C≡C—C≡C—; L.sup.13 to L.sup.16, L.sup.21 to L.sup.23, and L.sup.31 to L.sup.36 are hydrogen or fluorine; Y.sup.11 and Y.sup.12 are hydrogen or fluorine; and n.sup.1 is 0.

A polymer having excellent liquid crystal alignment and electrical properties and thus is suitable for use as a liquid crystal alignment agent, a liquid crystal alignment agent including the same, a liquid crystal alignment film formed from the liquid crystal alignment agent, and a liquid crystal display device including the liquid crystal alignment film are provided.

A polymer having excellent liquid crystal alignment and electrical properties and thus is suitable for use as a liquid crystal alignment agent, a liquid crystal alignment agent including the same, a liquid crystal alignment film formed from the liquid crystal alignment agent, and a liquid crystal display device including the liquid crystal alignment film are provided.

Shown is a compound represented by formula (1). For example, R.sup.1 is alkyl having 1 to 15 carbons; MES is a mesogen group having at least one ring; Sp.sup.1 is a single bond or alkylene having 1 to 10 carbons; M.sup.1 is methyl; and R.sup.2, M.sup.2 and M.sup.3 are hydrogen. ##STR00001##

The invention relates to novel anisotropic compounds of formula (I) ##STR00001##
as well as liquid crystalline mixtures, films and electro-optical devices comprising the compound.

A material used in an element for phase control of an electromagnetic wave signal having a frequency of 1 GHz to 10 THz. A liquid crystal composition containing at least one compound selected from a group of compounds represented by Formula (1), at least one compound selected from a group of compounds represented by Formula (2) and at least one compound selected from a group of compounds represented by Formula (3). In Formulae (1) to (3), R.sup.1, R.sup.21, R.sup.22, R.sup.31, and R.sup.32 may be alkyls having 1 to 12 carbon atoms; a ring A.sup.1 may be 1,4-phenylene; Z.sup.11, Z.sup.13, Z.sup.21, Z.sup.23, Z.sup.31, and Z.sup.33 may be single bonds; Z.sup.12, Z.sup.22, and Z.sup.32 may be C?C or C?CC?C; L.sup.13 to L.sup.16, L.sup.21 to L.sup.23, and L.sup.31 to L.sup.36 may be hydrogen or fluorine; Y.sup.11 and Y.sup.12 may be hydrogen or fluorine; and n.sup.1 may be 0. ##STR00001##

Shown is a compound represented by formula (1). For example, R.sup.1 is alkyl having 1 to 15 carbons; MES is a mesogen group having at least one ring; Sp.sup.1 is a single bond or alkylene having 1 to 10 carbons; M.sup.1 is methyl; and R.sup.2, M.sup.2 and M.sup.3 are hydrogen.

##STR00001##

The present invention relates to a switch element, which is thermoresponsive and which switches between a less transmissive state for radiant energy and a more transmissive state for radiant energy, and which comprises a liquid-crystalline medium. The invention furthermore relates to the use of the switch element for the regulation of radiant energy flow between interior spaces and the environment and for the regulation of the temperature of interior spaces. The invention furthermore relates to a liquid-crystalline medium, characterised in that it comprises 5-95% of a compound of the formula (I), in particular for use in the switch elements according to the invention.

The present invention relates to nematic liquid-crystal media of negative dielectric anisotropy which have a peak time (t.sub.max.) of 0.25 ms or less, which is determined as described in the disclosure, and which preferably have a value of the quotient of the peak time and the square of the birefringence (t.sub.max/n.sup.2) of 22 ms or less, and to the use of these liquid-crystal media in liquid-crystal displays, and to these liquid-crystal displays.