JPS59112974A - Novel tetrazine compound - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel tetrazine compound, which can be used in electro-optical devices for the purpose of modulating transmitted or incident light, particularly for coloring numbers, symbols and figures (17). It can be applied as a nematic liquid crystal material.

It is well known that the preferential orientation of nematic liquid crystals can be changed by adjusting the temperature. This orientation change can be used in various ways for light modulation, in particular for colored numerical or symbolic representations and graphical reproduction. One known method is based on isotropically aligning a nematic liquid crystal with negative dielectric anisotropy between two glass plates coated with a transparent conductive coating (N-connection). When this effect is brought between two crossed polarizers, the light that is transmitted or reflected after applying a voltage appears colored (DAP-effect) / M, F, 5
Chiekel, Fahrenschen: App
liea Physics Letters Volume 19 3
91 pages (1971).

Another known method is to orient a nematic liquid crystal with dielectric constant anisotropy in such a way that the long sleeves of the molecules are, on average, parallel to the confining electrodes (CP). When a single P layer is placed in an oblique position between crossed polarizers and a voltage is applied to the electrodes, the color of the transmitted or reflected light can be controlled by the voltage (DP- Effect) / H, Zasehke, HoSC
Hubert, F., Kuechel, F. Dinge
r, D, Demus, Q Soul General Purpose Patent No. 95892.

Since both methods use two polarizers, some of the incident light is lost through absorption. The special manufacturing technology cone arises from the fact that in both methods the layer thickness must be kept constant within a very narrow range (approximately ±1 μ). Furthermore, the observed interference colors are extremely sensitive to voltage and temperature variations.

These disadvantages can be partly avoided by methods which are also already known. In that case, twisting (Verdrillun)
g) An optical acetate with a weakly twisted nematic or cholesterin layer serves for colored modulation of the light. Suitable dyes, either non-liquid-crystalline or in the form of nematic-smectic or cholesterin compounds, are added to the liquid-crystalline material with as high anisotropy as possible. Between crossed polarizers these cells give colored light under transmitted or incident light and exhibit dimming when an electric field is applied (F, Fusch
el, D., Demue, G., Pe1zl, East German General Purpose Patent No. 11611,15). However, the drawbacks resulting from the use of two polarizing filters remain.

Furthermore, a method is also known that allows colored light modulation by a liquid crystal display tube using only one polarizer.

This method is based on the guest-host effect (Gj(,
Hellroeier, L.A., Zanoni, A.
pplied Physics Letters, Vol. 13, p. 91 (1968)), which utilizes a positive dichroism dye dissolved in a nematic liquid. When this liquid-crystalline material mixture exhibits positive-sign dielectric constant field tropism, two layers are produced from it.

This Pi appears colored in light control when the direction of the 4-moment of incorporated dye molecules coincides with the direction of vibration of light. After applying one pressure, a change from colored to weakly colored or colorless is observed. For visual reasons, it is advantageous if the liquid crystal mixture has negative dielectric anisotropy and starts from a single N layer. In this case, this layer is colorless or weakly colored in the absence of voltage, but becomes colored when uniformly reoriented by an electric field. The purpose of creating an electro-optical device in which electrically controlled areas (numbers, letters, etc.) are strongly colored and stands out in strong contrast to the surrounding non-electric field area cannot be satisfactorily achieved by this method. . This can be attributed to the fact that the known nematic liquid crystals with negative anisotropy, which are suitable as components, require excessive operating times (more than 10 cm).

Another drawback of known color modulation methods of light is that the dyes used are often difficult to dissolve in nematic liquid crystal materials. In these cases only weak color contrast is obtained.

In addition, if the γ quality used is low, there is a risk that the dye will precipitate. Furthermore, the light fastness of conventionally used dyes is insufficient and color contrast decreases when used for a long time.

The object of the present invention is to provide an electro-optical device for the modulation of transmitted or incident light and for the R4 representation of KM letters, symbols and figures, which exhibits a good color contrast at low voltages and degrees of use. be.

The object of the present invention is to have high chemical and thermal stability, strong intrinsic coloration, remarkable dichroism within the visible spectrum range, sufficiently low melting point, sufficiently high clarification point, and good light resistance. The object of the present invention is to provide a new nematic liquid crystal material.

General formula where R1 is Br −, CI −, CnH2n+, −
, 0nH2n+, O- (Dke 1-10), R1 is cnH
2n++ CD means 2-10), a new tetrazine compound is used as a nematic liquid crystal material for the modulation of transmitted or incident light and for the reproduction of numbers, symbols and figures. It was found that it can be used for.

These liquid crystal materials have high chemical and thermal stability, strong intrinsic colors, pronounced dichroism in the visible spectrum range, low melting points, sufficiently high clearing points, and good light resistance.

By vertically structuring several of these liquid-crystalline substances or mixtures of these substances with other liquid-crystalline compounds, it is possible to lower the melting point still considerably and to widen the operating temperature still considerably. The transition temperature T of the liquid crystal material of the present invention is shown in Table 1 below. In this table, K is in a crystalline solid state, S is in a smectic state, a-Q,
N represents a nematic state, and ■ represents an isotropic liquid state.

Dots below these symbols indicate the presence of that condition, and lines indicate the absence of that condition. Displays in parentheses indicate transitions within the unstable region. 4 The unit of one degree of displacement is °0.

The novel compounds of the present invention can be synthesized according to the following reaction formula: A 5-(4-substituted phenyl)-6-n-furkyl-1,2,4,5-tetrazine Variation 1 Variation 2 Table 1 Nr, R' R” K 8
N Engineering 1/1. 06H+s 07H
15,41(,27) -1/2 04H9QC
5H,,,551)-,59,5・1/3 04)19
006H,3,49-,571/4 04H900,
H, 5, 47 (, 43), 621/ 8 0sH
++007H15,49,52,5,631/9
C6H+sO05H,,,5s,6s'-
1) An unstable solid melts at 53.5'C2
) Monomorphic nematics 3) Unstable solids melt at 43'O 4) A transition is observed in the smectic region at 65-68°C.

Example 1゜3-(4-butoxyphenyl)-6-n-hexyl-1
, 2,4,5-tetrazine (1/l) (variation 2) N-hexanoyl-N'-[4-butoxybenzoyl] in a three-ring flask equipped with a thermometer, stirrer and distillation equipment.
Hydrazine 0.03 molt Pc420.9 (0,0
9 mol) and stirred under vacuum until 140'0
Heat to. The reaction mixture becomes liquid and po O/! 3
"Pal," he says, and leaves. The reaction is complete if no more PoCl3 is produced. After cooling, drain the contents of the flask into ether and carefully add ice while cooling. The ether extract is then washed with water and bicarbonate solution, dried over Na, So, and freed from the solvent on a rotary evaporator. 1.4-dichloro-
1-(4-Butoxyphenyl]-4-hexylazine is produced as a tan oil and is further processed as crude product.

The oil is suspended in 50-80 vO of absolute ethanol and cooled to -5'C. Ether (approximately 20 ml) is then added until a clear solution results. A solution of 41 parts of hydrazine in 20 m of ethanol is added dropwise while stirring so that the temperature does not exceed 00. Next, 2 more
Stir at room temperature for an hour. The resulting dihydrotetrazine was suctioned from door to door, and NaNO0. and oxidized with acetic acid to give tetrazine. Purification of the product is carried out by recrystallization or column chromatography. The yield is 20% of theory.

Other compounds listed in Table 1 were similarly prepared. The yield was 10-20% of theory.

Example 2 6-(4-butoxyphenyl)-6-n-benziroot 2,4,5-tetrazine (1/2) (variation 1) 4-butoxybenzimide ester-hydrochloride D
-005 mol, pentyl-amidine hydrochloride 0
．． 015 mol and hydrazine hydrad (80 to 10)
Stir the 30-zone in the chamber for 2-5 hours. Next, the contents of the flask are poured into water, and the precipitate is vacuumed and washed.

The precipitate was suspended in NaNO210 to a solution range of 60 to 40, stirred gently with 70 ml of ether, and oxidized to tetrazine by adding 10% acetic acid little by little.

The ether extracts are washed, dried with Na, So, and the solvent is removed on a rotary evaporator. The residue is purified chromatographically on silica gel using methylene chloride as the eluent. The theoretical yield is 40 i.

Other compounds listed in Table 1 were similarly prepared.

The yield was 20-50% of theory.

Example 3: Using 1/4 of the material, a thickness of about 1
Create a 0μ orientation layer (P layer). This layer appears colorless in the absence of space when the vibration direction of the incident polarized light matches the preferred direction of the P layer. When applying a 15V power at 56°C, the layer turns reddish-purple after the distribution is changed. Distribution time 1d-30
ms, 71 months at the time of collapse is 90me. The color change from pale red to reddish-purple and vice versa is also observed in unpolarized white light. When a line color filter is inserted in the optical path, a change from bright edge to black appears after applying an electric field.

Example 4 A mixture of the following composition is made: 4,-n-propylcyclohexane carboxylic acid-4-
Cyan, phenyl ester 255 mol X4-n-
Butyl-cyclohexanecarboxylic acid-4-cyan-phenyl ester 24 mol% 4-
n-Benzylcyclohexanecarboxylic acid-4-cyan-phenyl ester 25.5 mol π substance 1/4
25 mol% This mixture is nematic and red colored at room temperature. Dichroism is negative. This mixture is used to create a P layer with a thickness of about 20μ between the transparent electrodes. Under white line polarized light whose imaging direction coincides with the preferred direction of the P layer, the transmitted or reflected light appears colored in a faded rose color. A strong red coloration appears after applying a voltage of 3V.

The device was exposed to sunlight for 600 hours. After that, no change in dimming was observed in the visible spectral range compared to the original state.

Example 5 In the mixture described in Example 4, 0.9 weight of a dichroic old yellow dye "Wolfen 6" having the following chemical structure is dissolved.

When the preferential direction of the P layer made of this mixture matches the vibration direction of the incident polarized light, the transmitted or reflected light appears yellow, but after being exposed to 5 V (50 Hz), it appears red. A discoloration appears. Figure 1 shows the relationship between the transmittance of a display tube filled with this mixture and the wavelength as l1j11!
The following shows the case of 20μ: where 1 is a state with no field, 2 is 1.2V, 3 is 1.5V, 4 is 6. Ov's,
5 represents after applying an AC voltage of 10V.

Example 6 In addition to the mixture described in Example 5, 0.4 weight π of indophenol plow was dissolved. Indophenol plow is a positive dichroic pigment.

A P layer with a thickness of 20 μm is made from the mixture thus obtained. When the preferred direction of this layer matches the direction in which incident polarized light is captured, the transmitted or reflected light appears green. When an AC voltage of 3V is applied, the layer turns red.

[Brief explanation of the drawing]

The figure shows the relationship between the light transmittance and the wavelength of a display tube using a liquid crystal material having a temperature of 5 according to the present invention. Agent: Hikaru Esaki Good agent: Fumi Esaki 400 500
600 700 800 wavelength (nm
) German Democratic Republic 402 Hare Franzstrasse 13 M Author Gerhard Perzl German Democratic Republic 402 Haare Leniner 297 0 Inventor Hans Ulrich Notnikuts German Democratic Republic 77 Hoierswerda Robert Schumannstrasse 0 Inventor Willibald Schliemann German Democratic Republic 402 Halle Herder Strasse 9

Claims (1)

Scope of Claims: General formula [wherein R1 is a Br-, Ol-, OnH2+1- or CnH2n+10- group (n is 1 to 10), and R2 is a C11H2n+1- group (n is 2 to 10) be)
It is. ] A tetrazine compound represented by