JPS60204731A - New tolan-based nematic liquid crystal 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 novel nematic liquid crystal compounds of transconductors useful as electro-optic display materials. The novel nematic liquid crystal compound provided by the present invention is a compound represented by the general formula %.

M-Shut (MeS) is a typical liquid crystal display cell.
ehadri etc. (APPLIED PHYSIC8l, E
TTER81B, 127-128 (1971)) or the field effect mode cell proposed by G.H.
CEEDING OF THE 1. E, E, E, 5<
51162-1171 (195B)) or the dynamic scattering mode cell proposed by G.H. Beilmeier (G-
HHei1m@1sr) etc. (APPI, IED PRY
SIC8LETTEEt813.91 (196B))
(D L'Whi)
te) etc. (JOURNAL OF APPLIEDPH
There are guest-host star cells proposed by Y8IC845, 4718 (1974).

Among these liquid crystal display cells, the mainstream one at present is a TN type cell, which is a type of valve effect type cell. In this TN type cell, G, Bauer K, Mo, Cry
mt, Liq.

As reported in Cryst, 6345 (1981), the anisotropy of the refractive index of the liquid crystal material filled in the cell is used to prevent the generation of interference fringes on the cell surface that would impair the appearance of the cell. It is necessary to set the product of (Δ龜) and cell thickness d) μmo to a specific value. In practically used liquid crystal display cells, the values of Δnod are o, s, to, t6.
or 2.2. In this way Δ
Since the value of nod is set to a constant value, the value of d can be made small by using a liquid crystal material Nk with a large value of Δn. As the value of d becomes smaller, the response time (τ) becomes smaller according to the well-known relational expression of ταd2. Therefore,
A liquid crystal material with a large value of Δn is an extremely important C31 material for producing a liquid crystal display cell that has a fast response speed and is free from interference fringes. On the other hand, most practical liquid crystal materials consist of a compound that has a nematic phase near room temperature and a compound that has a nematic phase at a temperature higher than room temperature.
It is prepared by thoroughly mixing one or more ingredients. Many of the above-mentioned mixed liquid crystals currently in practical use are required to have a nematic phase over the entire temperature range of at least -30°C to +65°C, but the variety of applied products of liquid crystal display cells is As a result of this trend, there is a demand for liquid crystal materials that extend the nematic liquid crystal temperature range to higher temperatures.Recently, nematic liquid crystal compounds with a particularly high nematic phase-isotropic liquid phase (N-I) transition temperature have been developed. is needed.

The compounds of formula (I) according to the invention have a large Δn and a high N
-I is a novel nematic liquid crystal compound having a transition temperature. Therefore, a practical mixed liquid crystal material having a large Δn and a high N-1 transition degree can be prepared simply by mixing the compound of formula (I) with various parent liquid crystals.

The compound of formula (I) according to the present invention can be produced according to the following production method. R and R' in each of the following formulas (n) to (Vl) have the same meanings as R and R' in formula (I), respectively.

1st step - A compound of formula (Ill) is produced by reacting trans-4-n-alkyl-1-phenylcyclohexane with a compound of formula (II) and anhydrous aluminum chloride in carbon dichain or nitrobenzene.

Step 2 - The compound of formula (m) produced in step g1 is reacted with a reducing agent such as lithium aluminum hydride in anhydrous ether or anhydrous TiIF to produce a compound of formula (IV).

Step 6 - A dehydrating agent such as potassium hydrogen sulfate is added to the compound of formula (IV) produced in the second step, and the compound is heated and dehydrated to form the compound of formula (IV).
Produce the compound V).

Fourth step - The compound of formula (V) produced in the third step is added with carbon tetrachloride or chloroform or 1111,1
The compound of formula (Vl) is prepared by addition of bromine in a solvent such as , 2-trichloroethane.

Step 5 - The compound of formula (Vl) prepared in step 4 is treated with 1,5-
A compound of formula (1) is prepared by reacting with a base such as diazabicyclo(5,4,0)undecene-5.

Table 1 lists the transition temperatures of representative compounds of formula (I) thus produced.

Table 1 shoulder RR' Transition temperature ('C) 1C,H, -11-C,H? -194℃(cm)
goo℃ or higher (and 4) 2 CBH4-n-C,) 111
-210℃ (0-1) 500℃ or more (Nil) 3
n-C, B, I-n-C, H, -1a5℃ (C-IN)
300℃ or higher (Embarrassing 4 n-CBH, -n-C, Hl
l-202℃ ((, *N) 500℃ or more (Nt=tI
) In the table, C represents a crystalline phase, N represents a neutral phase, and ■ represents an isotropic liquid phase.

The compound of formula (I) according to the present invention is a nematic liquid crystal compound containing a weak negative dielectric anisotropy. It can be used as dynamic light scattering display cell material in mixture state, and it can also be used as field effect display cell material in mixture state with other nematic liquid crystal compounds that have strong positive dielectric constant anisotropy. It can be used as

Preferred representative examples which can be used in this process in combination with the compound of formula (I) include 4,4'-substituted benzoic acid phenyl ester, 4,4'-substituted cyclohexanecarboxylic acid phenyl ester, a , a'-Ml-converted cyclohexanecarboxylic biphenyl ester, 4 (4
-Substituted cyclohexanecarbonyloxy)benzoic acid 4'
→Substituted phenyl ester 4 (4-substituted cyclohexyl)
Benzoic re'a'-substituted 7 enyl ester, 4 (4-substituted cyclohexyl)benzoic acid a I-substituted cyclohexyl ester, 4.4'-substituted biphenyl.

Examples include 4,4'-substituted phenylcyclohexane, 4,4'-substituted terphenyl, 4,4'-biphenylcyclohexane, 2(4'-substituted phenyl)5-substituted pyrimidine, and the like.

Table 2 shows the parent liquid crystals (90% by weight of AI) that are currently widely used as nematic liquid crystal materials with excellent time-division driving characteristics and the compound of formula (I) 41.mu2./#6 shown in Table 1.
N-I point and refractive index anisotropy (Δ11)' measured for each mixed liquid crystal consisting of 101 quantities of each of A and Mu4.
For comparison, the N-I point and Δnt-n point measured for the parent liquid crystal (At itself) are shown.
The parent liquid crystal is
t9 (L110) According to the data listed in Table 2, the compound of formula (I) raises the 0N-I point of the host liquid crystal in a practical amount of light, but tΔ
It can be seen that n can be increased significantly.

The effects of the present invention are also clarified by the following comparative experiments. A known compound of the formula (%) whose chemical structure is similar to the compound of formula (1) according to the present invention and which is used for the purpose of increasing the 0N-I point of the mixed liquid crystal is added to the above-mentioned base liquid crystal (Al). Mixed in various proportions.

Similarly, one of the compounds according to the invention, namely the formula %formula %(44
) were mixed with the parent liquid crystal (Al) in various proportions.For the two kinds of mixed liquid crystals obtained in this way, each N-
One point and Δnt- were measured. Based on these measurement results,
FIG. 1 of the attached drawings shows the relationship between the NI point and the amount added, and FIG. 2 shows the relationship between Δn and the amount added.

From these facts, it can be understood that the compound of formula (I) according to the present invention can significantly increase the N-I point and Δn of the parent liquid crystal as compared to typical known similar compounds.

Example: 9 g of anhydrous aluminum chloride (0,
9.41 (0,0500 moJ) of trans-4-ethyl-, l'-phenylcyclohexane and trans-4-n-probylfuclohexylphenylcyclohexane) were added to this solution while heating under reflux. 14 JI (0,0500 moJ) of mixed water was added dropwise. After heating under reflux for 1 hour, the neated carbon system was distilled off, and the product was added to ice water and stirred at 60°C for 1 hour. After cooling, the product Extracted with toluene, washed with water, and dried.

After distilling off the toluene, recrystallization was carried out with ethanol to obtain 18 g (0,0420 moJ) of the following compound. Obtained.

This compound contains 71 (dilithium aluminum 16
Mixture of 9(0,t1420moJ) and anhydrous T)lF8ON a11. Gradually add the crystals to the solution, react for 1 hour at room temperature, add 9% HCA 150 mA and water 150 M to the reaction solution, extract the product with toluene, wash with water, dry, and distill off the toluene from the extract. do. The obtained crystals were dissolved in 300ml of toluene, and 1.5J of hydrogen potassium was added to this mortar. (0,0110 mol) was added and heated under reflux for 1 hour while removing water. Reaction wave, inorganic matter filtration,
Its "tIPS crystallized and the following compound 14.1' (0,0
350 moj) was obtained.

This compound was dissolved in 250 parts of 1.1.2-) dichloroethane, and 5.6 I of bromine (0,0350 moJ) was added at room temperature.
? The mixture was added dropwise and reacted for 1 hour, and the precipitated crystal II was collected by filtration, washed with methanol, and dried. Obtained compound '4
1,5-diazabicyclo[5,4,0)undecene-514,9 (0,0921 moj') was added to this solution and heated under reflux for 3 hours. Thereafter, the product was extracted with toluene, washed with water, dried, and crystallized again with ethanol-acetone to obtain 8 g (0,0200 moJ) of the following compound.

Yield rate 40.0% Transition temperature 194℃ (C→N) 300℃ or higher (NaI) Example 2 The following compound was obtained in the same manner as in Example 1.

Yield rate 37.5% Transition temperature 210℃ (C-+N) 600℃ or higher (NdI) Example 3 The following compound was obtained in the same manner as in Example 1.

Yield rate 34.7% Transition temperature 185℃ (C-+N) 300℃ or more (NOI) Example 4 The following compound was obtained in the same manner as in Example 1.

Yield rate 66.4% Transition temperature 202℃ (C→N) 300℃ or more (Ngl)

[Brief explanation of drawings]

Figures 1 and 2 are one of the compounds according to the present invention/#
64 compounds and known compounds with similar structure t (1
1) The relationship between the N-I point and the added amount of the mixed liquid crystal obtained by adding each of the above to the currently widely used base liquid crystal (Al), and the N
- A chart showing the relationship between the I point and the refractive index anisotropy Δn. Kuzu 1 Figure 1111 Known compound combination ((A) -1-(ku)) [(A) + (Mekaripe5 10 (A) + (a) I:N#ru( Q);1t2(A) 10(doA)I=r#Kk(PJoA) t>I+'
/.

Claims (1)

[Claims] general formula A compound represented by