A device for regulating the passage of energy from an outside space into an inside space includes a switching layer, where the switching layer comprises one or more compounds of the formula: ##STR00001##
wherein R.sup.1, Z.sup.1, Z.sup.2, Ar.sup.1 and X are defined herein.

A linear polarizer may be formed a blue dichroic dye compound, having a maximum dichroic ratio Kd?12 in an entire visible wavelength range, and a red dichroic dye compound, having a maximum dichroic ratio Kd?16 in the entire visible wavelength range. The linear polarizer has a dichroic ratio Kd?18 and a thickness of less than or equal to 2 micrometers. The linear polarizer may form an achromatic polarizer.

The present invention relates to liquid crystalline media comprising one or more benzothiadiazol derivatives of formula I,

##STR00001##

in which R.sup.11, R.sup.12, A.sup.11, A.sup.12, A.sup.21, A.sup.22, Z.sup.11, Z.sup.12, Z.sup.21, Z.sup.22, W, X.sup.11, X.sup.12, r and s have the meanings indicated in claim 1, to the use of such liquid crystal media for optical, electro-optical and electronic purposes, in particular in devices for regulating the passage of energy from an outside space into an inside space, for example in windows.

An electro-polarizable compound has the following general formula:

##STR00001## where Core1 is an aromatic polycyclic conjugated molecule having two-dimensional flat form and self-assembling by pi-pi stacking in a column-like supramolecule, which is tetrapirolic macro-cyclic fragment, R1 is an dopant group connected to Core1, m is number of R1 which is equal to 1, 2, 3 or 4, R2 is a substituent comprising one or more ionic groups, p is number of R2 which is equal to 0, 1, 2, 3 or 4. The fragment marked NLE containing the Core1 with at least one R1 has a nonlinear effect of polarization. Core2 is an electro-conductive oligomer self-assembling by pi-pi stacking in a column-like supramolecule, n is number of Core2 which is equal to 2, or 4, R3 is a substituent comprising one or more ionic groups, s is number of R3 which is equal to 0, 1, 2, 3 or 4. R4 is a non-polar resistive substituent, k is a number of R4 which is equal to 0, 1, 2, 3, 4, 5, 6, 7 or 8.

The application relates to a device for regulating the entry of light into a room, which comprises a switchable layer of specific design comprising a twisted nematic liquid-crystalline medium and a dichroic compound.

The present application relates to a device for regulating the passage of light through a light-transmitting area which comprises a switching layer comprising a liquid-crystalline medium comprising at least one dichroic dye, where the parameters degree of light transmission and degree of anisotropy of the device are selected in a certain manner.

An electro-polarizable compound has the following general formula: ##STR00001##
Core1 is an aromatic polycyclic conjugated molecule having two-dimensional flat form and self-assembling by pi-pi stacking in a column-like supramolecule, R1 is a dopant group connected to Core1; a number m of R1 groups is 1, 2, 3 or 4. R2 is a substituent comprising one or more ionic groups connected to Core1; a number p of ionic groups R2 is 0, 1, 2, 3 or 4. The fragment marked NLE has a nonlinear polarization effect. Core2 is an electro-conductive oligomer self-assembling by pi-pi stacking in a column-like supramolecule, a number n of 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 providing solubility of the compound in a solvent and electrically insulating the column-like supramolecules from each other. A number k of substituents R4 is 0, 1, 2, 3, 4, 5, 6, 7 or 8.

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 element includes a pair of substrates disposed to face each other, a liquid crystal layer disposed between the pair of substrates, and a liquid crystal alignment layer provided on each of the liquid crystal layer sides of the pair of substrates. The liquid crystal layer includes a compound having an alkenyl structure and a compound having a terphenyl ring structure, or includes a compound having an alkenyl structure and a terphenyl ring structure in the same molecule, and the liquid crystal alignment layer is a layer comprising a liquid crystal alignment agent containing a polymer (P) which has at least one selected from the group consisting of a radical polymerizable group, a photoinitiator group, a nitrogen-containing heterocyclic ring (excluding imide rings in polyimides), an amino group and a protected amino group.

The application relates to a liquid-crystalline medium comprising at least one dichroic dye having a rylene structure which absorbs red light. The application furthermore relates to a device, preferably a device for the regulation of the passage of energy through a light-transmitting area, which contains the liquid-crystalline medium.