JP3106664B2 - New metal complex liquid crystal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel metal complex liquid crystal compound which is useful as an optical display material or an optical recording material, and more particularly, is useful as a charge transport material for a liquid crystal device, a molecular element or an electrophotographic photoreceptor. .

[0002]

BACKGROUND OF THE INVENTION Generally, organometallic complexes are useful as catalysts or pigments. It is known from the following literature that this complex can be expected to exhibit new physicochemical properties when it exhibits a liquid crystal phase.

(1) Chem. Ber., 59,962 (1926) (2) Liquid. Cryst., 1,215 (1986) (3) Mol, Cryst. Liq. Cryst., 13, 305 (1971) (4) Mol, Cryst. Liq. Cryst., 20, 133 (1973) (5) Mol, Cryst. Liq. Cryst., Lett, 34, 117 (1976) (6) J. Chem. Soc., Chem. Commun., 1980, 797 (7) Mol. Cryst. Liq. Cryst., 43, 53 (1977) (8) JCS Chem., Chommun, 1986, 581 (9) Mol. Cryst. Liq. Cryst., 84, 207 (1982) (10) S. Chandrasekjar, BKSadashiva and BSSrikan
ta, preprint (11) Khim. Teknol. Krasheniya, Sint. Krasitelei po
lim. mater., 1981, 60 (12) Dokl. Akad. Nauk SSSR, 276, 126 (1984) (13) Mol. Crust. Liq. Cryst., 123, 369 (1985)

The organometallic complexes exhibiting a liquid crystal phase described in the above-mentioned documents are listed below.

[0005]

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[0006]

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[0007]

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[0008]

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[0009]

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[0010]

However, most of the above-mentioned conventional metal complex liquid crystal compounds are easily thermally decomposed at a clear point, and it is difficult to obtain a chemically stable liquid crystal device. Moreover, very few discotic columnar liquid crystal phases are useful as one-dimensional organic conductive materials, which is the reason why a charge transfer complex composed of only discotic liquid crystals cannot be produced.

An object of the present invention is to provide an electron-donating and thermally stable metal complex having a discotic columnar liquid crystal phase.

[0012]

According to the present invention, there is provided a compound represented by the general formula (I):

[0013]

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(Wherein R represents an alkyl group having 1 to 20 carbon atoms, but preferably represents a linear alkyl group having 1 to 20 carbon atoms).

Further, the present invention provides a discotic columnar liquid crystal composition containing the compound represented by the general formula (I), and further has a layer containing the liquid crystal composition on a substrate, and has a color depending on temperature. Provide a liquid crystal device utilizing a changing thermochromism phenomenon.

The compound of the general formula (I) according to the present invention is
For example, it can be manufactured according to the following manufacturing method.

[0017]

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(In the above, R in the general formula (III)
Has the same meaning as R in formula (I). )

First step-The compound of the formula (II) is dissolved in a polar solvent such as dimethylacetamide, and calcium carbonate and alkyl bromide are added thereto, and the mixture is heated to about 70 ° C. to react. The reaction mixture is extracted with a chlorinated solvent such as dichloromethane, and the extract is washed with water and dried, and then the solvent is distilled off from the extract. Next, the compound of the general formula (III) can be produced by recrystallizing the reaction product from ethyl acetate.

Second step: NH ₂ OH.HCl and potassium hydroxide are added to ethanol, and the mixture is vigorously stirred and filtered. The compound of the formula (III) produced in the first step is added to the filtrate, and the mixture is refluxed under a nitrogen stream. After a solution of K ₂ PtCl ₄ in ethylene glycol is added thereto, the reaction solution is neutralized with acetic acid and further refluxed. After cooling, filtration, column purification, and recrystallization from a mixed solvent of acetone and chloroform, the compound of the general formula (I) according to the present invention can be produced.

Table 1 shows the phase transition temperatures of the typical compounds represented by the general formula (I) thus produced.

[0022]

[Table 1]

(In the table, C represents a crystal phase, D1 represents a discotic phase 1, D2 represents a discotic phase 2, D represents a discotic phase, and I represents an isotropic liquid crystal phase.)

The compound of the general formula (I) of the present invention can be obtained by observing the liquid crystal phase with a polarizing microscope and analyzing the X-ray structure to obtain a discotic columnar liquid crystal phase, specifically, a Dhd phase (Dish.
It was revealed that the metal complex had an electron-donating metal complex having a cotic hexagonal disordered columnar phase).
Therefore, it can be understood that it is useful as a charge transporting material of an electrophotographic photosensitive member.

Further, it was revealed that the compound No. 1 in Table 1 shows two kinds of discotic columnar liquid crystal phases. Further, it was revealed that the compounds of No. 2 and No. 3 exhibited a discotic columnar liquid crystal phase at room temperature, and had a discotic columnar liquid crystal phase in an extremely wide temperature range.

These compounds exhibit a green color at room temperature, exhibit thermochromism in which the color changes dramatically to red with increasing temperature, and this color change has been found to be reversible. Therefore, the compound of the present invention having such characteristics can be applied to a liquid crystal device.

[0027]

EXAMPLES Examples of the present invention will be shown below to further explain the present invention. However, the invention is not limited to these examples.

The structure of the compound was confirmed by NMR and IR. CDCl _{3 in} NMR represents a solvent, t represents a triplet, and m represents a multiplet. (KBr) in IR represents measurement by tablet molding.

(Example 1-a) 2.42 g (17.5 mmol) of K ₂ CO ₃ and 3.38 g of nC ₈ H ₁₇ Br (1
7.5 mmol), and then formula (A)

[0030]

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3,3 ', 4,4'-Tetrahydroxybenzyl 1.
20 g (4.38 mmol) were added as a 28 ml solution of dimethylacetamide. The solution was heated in an oil bath under a nitrogen stream, and reacted at 70 to 100 ° C. for 10 hours. The reaction product was extracted with dichloromethane, the extract was Na ₂ S
After drying over O ₄ , the solvent is distilled off and the resulting extract is purified by recrystallization from ethyl acetate, yielding the compound of formula (B)

[0032]

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2.44 g of white fine needle crystals of the compound of the formula (1) were obtained.

Yield 77%, melting point 96 ° C. ¹ H-NMR (CDCl ₃ ) δ (ppm): 0.80 to 1.51 (m,
60H), 3.93 to 4.14 (t, 8H), 6.72 to 7.45 (m, 6
H) IR (KBr) 2940, 2860, 1670, 1580, 1520, 1270cm ^-1

(Example 1-b) In a 500 ml Erlenmeyer flask, 11.39 g (0.16 mol) of NH ₂ OH.HCl and 11.39 g (85%) of KOH were added.
6 mol), 141 ml of ethanol and 141 ml of methanol were added and stirred vigorously for 1 hour. After completion of the reaction, the precipitated KCl
And 2.00 g (2.77 mmol) of the compound of formula (B) obtained in (Example 1-a) was added to the filtrate, and the mixture was refluxed for 6 hours and 45 minutes under a nitrogen stream. 0.57 g (2.77 mmol) of K ₂ PtCl ₄ dissolved in about 20 ml of ethylene glycol
, The reaction solution is neutralized with acetic acid, and
Refluxed for 45 minutes.

After cooling to room temperature, the resulting dark green precipitate was filtered off. The precipitate was dried and purified by column chromatography (silica gel, developing solvent: chloroform), and then purified by recrystallization from a mixed solvent of chloroform and acetone to obtain 0.19 g of the following compound.

[0037]

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[0038]

(Example 2) In Example 1, C ₈ H ₁₇ Br
The following compounds were obtained in the same manner as in Example 1 except that C ₄ H ₉ Br was used instead of

[0040]

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[0041]

(Example 3) In Example 1, C ₈ H ₁₇ Br
The following compound was obtained in the same manner as in Example 1 except that C ₁₂ H ₂₅ Br was used instead of

[0043]

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[0044]

[0045]

The compound of the general formula (I) of the present invention has a discotic columnar liquid crystal phase centered on a platinum metal atom and stable over a very wide temperature range.
Useful as a one-dimensional organic conductive material. In addition, it has thermochromism in which the color changes reversibly depending on the temperature, and a liquid crystal device using this is also promising.

Continuation of the front page (56) References "Bull. Chem. Soc. Jpn.," (1978), Vol. 51, No. 11, pages 3257-3260 (58) Fields investigated (Int. Cl. ⁷ , DB name) C07F 15/00 C09K 19/40 G02F 1/13 500 CA (STN) REGISTRY (STN)

Claims (3)

(57) [Claims] 1. A compound of the general formula (I) (Wherein, R represents an alkyl group having 1 to 20 carbon atoms). 2. A discotic columnar liquid crystal composition comprising the compound represented by the general formula (I) according to claim 1. 3. A liquid crystal device having a layer containing the discotic columnar liquid crystal composition according to claim 2 on a substrate, wherein the color changes with temperature.