Described herein are heterocyclic liquid crystal compositions that can allow for the adjustment of their refractive indices by the application of an electric field. In addition, selectively dimmable reverse-mode polymer dispersed liquid crystal (PDLC) elements and devices using these compositions are also described, which are transparent when no voltage is applied and opaque when a voltage is applied.

To provide a liquid crystal display device that has a high off-response speed and a good balance between drive voltage and transmittance, is stable over time, and also has a high voltage holding ratio. A liquid crystal display device in which a liquid crystal layer containing a polymer network (A) and a liquid crystal composition (B) is disposed between two substrates having an electrode on at least one side thereof and having transparent properties on at least one side thereof, and the loss factor (tan ) (loss modulus/storage modulus) of the liquid crystal layer calculated from the storage modulus (Pa) and the loss modulus (Pa) in a sinusoidal vibration measured with a rheometer at 25 C. and at a measurement frequency of 1 Hz ranges from 0.1 to 1.

A polar compound having high chemical stability, high capability of aligning liquid crystal molecules, high solubility in a liquid crystal composition, and a large voltage holding ratio when the compound is used in a liquid crystal display device; and a composition containing the compound. The compound is represented by formula (1). In formula (1), for example, P.sup.1 is a group represented by any one of formulas (1b) to (1i), P.sup.2 is a group represented by formula (1d), Sp.sup.1 and Sp.sup.2 are a single bond, Z.sup.1, Z.sup.2, Z.sup.3, Z.sup.4 and Z.sup.5 are COO, and ring A.sup.1, ring A.sup.2, ring A.sup.3 and ring A.sup.4 are 1,4-phenylene:

##STR00001##

Disclosed is a compound containing a specific structure having an azomethine part, the compound being reversibly fluidized and non-fluidized by being irradiated with light.

Disclosed herein is a light emitting device and method of manufacturing such a device comprised of a series of photopolymerizable, chiral liquid crystalline layers that can be solvent cast on a substrate. The mixture of chiral materials in each successive layer may be blended in such a way that each layer has the same chiral pitch. Further the chiral materials in each layer may also be blended so that the ordinary and extraordinary refractive indices in each layer match the other layers such that the complete assembly of layers will optically function as a single relatively thick layer of chiral liquid crystal. The chiral nematic material in each layer can spontaneously adopt a helical structure with a helical pitch. The light emitting layers of the light emitting device can further comprise electroluminescent material that emits light into the band edge light propagation modes of the photonic crystal.

The present invention relates to heteroaromatic compounds which have two different reactive groups, their use in the synthesis of asymmetrically substituted compounds, and synthesis processes in which the compounds according to the invention are reacted sequentially with two different compounds, whereby an asymmetrically substituted compound is formed.

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.

An electro-polarizable compound has the following general formula: ##STR00001##
Core1 is an aromatic polycyclic conjugated molecule having two-dimensional flat form and that self-assembles to form supramolecular structures. R1 are electron donor groups connected to Core1 and R1 are electron acceptor groups connected to Corel, m is number of acceptor groups R1, m is a number of donor groups R. The numbers m and m are equal to 0, 1, 2, 3, 4, 5 or 6, but both m and m are not both equal to 0. R2 is a substituent comprising one or more ionic groups connected to Core1 directly or via a connecting group; a number p of ionic groups R2 is 0, 1, 2, 3 or 4. The fragment marked NLE has a nonlinear effect of polarization. Core2 is a self-assembling electro-conductive oligomer, a number n of the such oligomers is 0, 2, or 4. R3 is a substituent comprising one or more ionic groups connected to Core2; a number s of the ionic groups R3 is 0, 1, 2, 3 or 4. R4 is a resistive substituent electrically insulating the supramolecular structures from each other. A number k of substituents R4 is 0, 1, 2, 3, 4, 5, 6, 7 or 8.

A liquid crystal composition contains a liquid crystal compound; a photo-alignment compound; and a polymer obtained by polymerizing a monomer having two or more radically polymerizable double bonds and one or more hydroxyl groups.

The invention relates to novel compositions comprising at least two anisotropic compounds of formula ##STR00001##
as well as to liquid crystalline networks, films and electro-optical devices comprising the compositions.