A compound capable of providing a liquid crystal composition with high T.sub.ni, large n, low V.sub.th, large .sub.r, small tan .sub.iso, and satisfactory storability at low temperatures, and a liquid crystal composition, as well as a liquid crystal display element, a sensor, a liquid crystal lens, an optical communication device, and an antenna using the liquid crystal composition. Specifically, a compound represented by general formula (i) having an alkynyl group and an isothiocyanate group (NCS) and a liquid crystal composition containing one or two or more of such compounds.

Isothiocyanatoethynylbenzene derivatives of formula I ##STR00001##
liquid crystal media comprising the isothiocyanatoethynylbenzene derivatives, and high-frequency components comprising these media, especially microwave components for high-frequency devices, such as devices for shifting the phase of microwaves, tunable filters, tunable metamaterial structures, and electronic beam steering antennas (e.g., phased array antennas), and devices comprising said components. Further, an optical component comprising said liquid-crystalline media, operable in the infrared region of the electromagnetic spectrum, the use of said LC medium in the infrared (IR) region, and devices comprising said optical component.

An object of the present invention is to provide a liquid crystal composition with which a liquid crystal cured layer having both favorable aligning properties and favorable light resistance can be produced; and to provide a benzoquinone derivative, a liquid crystal cured layer, an optical film, a polarizing plate, and an image display device. The liquid crystal composition of the present invention is a liquid crystal composition containing a compound represented by Formula (A) and a liquid crystal compound.

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The present invention provides a liquid crystal composition which has excellent aligning properties of a liquid crystal compound and excellent adhesiveness between a liquid crystal layer after being cleaned with a solvent and a layer disposed adjacent to the liquid crystal layer, in a case of forming a liquid crystal layer. In addition, there is provided a compound which has excellent aligning properties of a liquid crystal compound and excellent adhesiveness between a liquid crystal layer after being cleaned with a solvent and a layer disposed adjacent to the liquid crystal layer, in a case of forming a liquid crystal layer by being mixed with a liquid crystal compound. In addition, there are provided an optically anisotropic layer, a cured film, and a diffraction element. The liquid crystal composition of the present invention contains a compound represented by Formula (1) and a liquid crystal compound.

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