A liquid crystal composition without requiring an alignment film or alignment treatment on a substrate. The problem is solved by a low molecular weight polar compound capable of homogeneously aligning a liquid crystal medium relative to the substrate, for example, a low molecular weight polar compound represented by formula (1):
M-P(1) In formula (1), M is a nonpolar group having 1 or more carbons, and P is a polar group.

Disclosed are a liquid crystal composition and a liquid crystal display device. The liquid crystal composition comprises at least one compound of general formula I, at least one compound of general formula II, at least one compound of general formula III, and at least one compound of general formula IV. By compounding the four compounds, the composition can have advantages of a wide temperature range of nematic phase, a low viscosity and a low threshold voltage, and the liquid crystal display element can have a short response time and great power saving performance.

Liquid-crystalline media containing one or more compounds of formulae I-1, I-2 and/or I-3 ##STR00001##
and one or more compounds of formulae II and/or III ##STR00002##
and components containing these media for high-frequency technology, in particular phase shifters and microwave array antennas.

An object of the present invention is to provide a composition that realizes high n, has a wide liquid crystal phase temperature range, small viscosity, excellent low-temperature solubility, and high resistivity and voltage holding ratio, and is stable against heat and light, and to provide a liquid crystal composition having an excellent lens effect and excellent chemical stability using the composition, and a liquid crystal display device and a liquid crystal lens that use the liquid crystal composition. The present invention provides a liquid crystal composition that contains one or two or more compounds represented by general formula (i) and one or two or more compounds represented by general formula (ii), a liquid crystal display device using the liquid crystal composition, a liquid crystal lens using the liquid crystal composition, and a birefringence lens for stereoscopic image display using the liquid crystal composition.

There is provided a liquid crystal composition which has favorable characteristics and excellent characteristic balance as a material for an element used for phase control of an electromagnetic wave signal with a frequency of 1 MHz to 400 THz. A liquid crystal composition which contains at least one compound selected from the group consisting of compounds represented by Formula (1), and is used for phase control of an electromagnetic wave signal with a frequency of 1 MHz to 400 THz:

##STR00001##

As a material to be used in a device used for phase control of an electromagnetic wave signal with a frequency of 1 MHz to 400 THz, a liquid crystal composition having a high maximum temperature of a nematic phase, a low minimum temperature of the nematic phase, large optical anisotropy, small dielectric loss, and thermal stability in a frequency range used for phase control and having good balance between characteristics is required. A liquid crystal composition used for phase control of an electromagnetic wave signal with any frequency of 1 MHz to 400 THz containing at least one compound selected from a group consisting of compounds represented by formula (1) and at least one compound selected from a group consisting of compounds represented by formula (2).

##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##

A liquid crystal compound comprising a specific compound having a positive dielectric anisotropy as the first component, and a specific compound having a low viscosity as a second component. Further, the liquid crystal compound may contain a specific compound having a positive dielectric anisotropy as the third component, a specific compound having a maximum temperature or a low viscosity as the fourth component, or a specific compound having a negative dielectric anisotropy as the fifth component.

A liquid crystalline compound, a liquid crystal composition, and a liquid crystal display element are provided. The liquid crystalline compound satisfying at least one physical property among high stability against heat and light, high transparency, low minimum temperature of the liquid crystal phase, low viscosity, proper optical anisotropy, negatively large dielectric anisotropy, proper elastic constant, good compatibility with other liquid crystalline compounds at room temperature and low temperature. The liquid crystalline compound represented by formula (1).

##STR00001##

A LC lens and a liquid-crystal medium used in said LC lens, wherein the medium contains one or more compounds of each of formulae I and II

##STR00001##