KR100496502B1 - Multifunctional Star-Shaped Discotic Liquid Crystals - Google Patents

Abstract

The present invention is a star-shaped disc-shaped liquid crystal having a rod-shaped substituent conjugated with oxadiazole and ethynyl group at 1,3,5-position of the benzene core represented by the following general formula (1); It provides a manufacturing method thereof.

[Formula 1]

Description

Multifunctional Star-Shaped Discotic Liquid Crystals

The present invention relates to a novel star type multifunctional disc type liquid crystal. In particular, the present invention relates to a novel star-type multifunctional disk-type liquid crystal having excellent electron transporting ability and blue luminescence properties and exhibiting various liquid crystal phases.

Disc liquid crystals, first published in 1977 (Chandrasekhar S, Sadashiva BK, Suresh KA, Pramana 1977; 7: 471), represent a new class of thermotropic liquid crystals.

The disc type liquid crystal refers to a substance in which a flexible alkyl group is substituted around an aromatic core, which is a disc-shaped rigid structure. Disc-shaped liquid crystals are classified into various liquid crystalline phases according to their chemical structure. As a representative example, disc-shaped liquid crystals (columnar phase) in which discs are stacked and columns are scattered like coins stacked vertically. Similarly, discs have a discotic nematic phase that is directional but not positional. In particular, disk-like liquid crystals that form columns form quasi-one-dimensional conductors due to the high charge carrier mobility formed along the axis of the column [Cammidge, AN, and Bushby, RJ, 1998, in Handbook of Liquid Crystals , Vol. 2B, edited by D. Demus, J. Gooby, GW Gray, H.-W. Spiess, and V. Vill (Wiley-VCH)], phtoconducting systems [Adam D, Schuhmacher P, Simmerer J, Haussling L, Siemensmeyer K, Etzbach KH, Ringsdorf H, Haarer D, Nature 1994; 37 1: 141], light emitting diodes [Christ T, Glusen B, Greiner A, Kettner A, Sander R, Stumpflen Tsukruk V, Wendorff JH, Adv. Mater. 1997; 9: 48], photovoltaic solar cells [L. Schmidt-Mende, A. Fechtenkotter, K. Mullen, E. Moons, RH Friend, JD MacKenzie, Science 2001, 293 , 1119]. In addition, nematic disc-shaped liquid crystals with negative birefringence are actively studied as optical compensation films that can improve the narrow viewing angle of existing nematic liquid crystal display devices caused by positive birefringence. [Mori H, Itoh Y, Nishiura Y, Nakamura T, Shinagawa Y. Jpn. J. Appl. Phys., 1997; 36: 143.

Typical materials used as disk cores for disk-type liquid crystals include benzene, triphenylene, porphyrin, phthalocyanine, and hexabenzocoronene. [Cammidge, AN, and Bushby, RJ, 1998, in Handbook of Liquid Crystals , Vol. 2B, edited by D. Demus, J. Gooby, GW Gray, H.-W. Spiess, and V. Vill (Wiley-VCH)].

However, the disk-type liquid crystals are limited in their application by showing a high transport speed for holes, rather than electrons, in a charge transporter on a column. In addition, there is a problem that the symmetry of C _6h becomes very complicated in order to form a disk in the form of a molecule. For example, in the case of a disc-shaped liquid crystal having a benzene core, an ethynyl group, an ester, or an amide group must be substituted at all positions 1 to 6 of benzene, which makes it difficult to manufacture and purify the same.

It is an object of the present invention to provide a novel disc-shaped liquid crystal compound having excellent electron transportability.

      Another object of the present invention is to provide a disk-shaped liquid crystal made of a novel compound for a disk-shaped liquid crystal, which is easy to manufacture and purify.

Another object of the present invention is a novel disc-shaped liquid crystal compound, which is composed of C _3h -symmetric structured star shape, and can realize column and nematic phases through chemical structure changes to various applications of disc-shaped liquid crystals. It is to provide a multi-functional disk-type liquid crystal that can be applied.

Another object of the present invention consists of a novel disc-shaped liquid crystal compound which exhibits strong fluorescence in itself, and can be used as a light emitting layer as well as an electron transporting layer in an LED. To provide.

The present inventors have substituted oxadiazole and ethynyl group having electron transporting ability at 1,3,5-position of benzene core, and as a result, the star form of C _3h -symmetric structure has surprisingly excellent electron transporting ability. The compound represented by the following general formula (1) which is easy to manufacture and purify was found and the present invention was reached.

Wherein n is 0 or 1, R ₁ is-(CH ₂ ) _x CH ₃ , R ₂ is H or — (CH ₂ ) _x CH ₃ , and x represents an integer between 5 and 21.

In the formula,-(CH ₂ ) _x CH ₃ is particularly preferably selected from hexyl, octyl, decyl, dodecyl or hexadecyl with x of 5, 7, 9, 11 or 15.

 The term used in the specification of the present invention has the following meaning.

The term 'liquid crystal material' is used hereinafter for both liquid crystal materials and mesogenic materials, and the term 'mesogen' refers to mesogenic groups of materials.

The term 'star' refers to the shape of three rod-shaped rigid structures connected at 1,3,5-positions of the benzene core at an angle of 120 degrees.

The term 'disc' refers to the shape of a molecule that has a disc shape, such as a coin.

The term 'column' refers to a state in which disk-like molecules are stacked, such as coins stacked in a row.

The term 'disc nematic phase' refers to a state in which disc-shaped molecules, such as scattered coins, have no ordering position but the normals of the discs point in one direction, that is, direction direction.

The term 'rigid structure' refers to a chemical structure that maintains a given shape without flexibility through conjugation or resonance, and has the meaning of 'mesogen'.

The compound of Formula 1 achieves excellent electron transport ability by selecting oxadiazole having excellent electron transport ability, and achieves strong blue fluorescence by π-conjugation of star-shaped rigid structure through oxadiazole which is a hetero aromatic ring. It was. In addition, the compound of Formula 1 may implement a column phase and a nematic phase by controlling the size of the star-shaped rigid structure by introducing an ethynyl group, and by converting an alkyl group substituted around it. Such a compound of Formula 1 is a novel material that is first discovered by the inventors and has not been introduced in any literature.

Preferred examples of the compound of formula 1 include 1,3,5-tris (2- (4-hexyloxyphenyl) -oxadiazol-5-yl) benzene, 1,3,5-tris (2- (4-dode Siloxyphenyl) -oxadiazol-5-yl) benzene, 1,3,5-tris (2- (3,4,5, -tris-dodecyloxyphenyl) -oxadiazol-5-yl) benzene , 1,3,5-tris (2- (4-hexyloxyphenyl) -oxadiazol-5-yl-ethynyl) benzene, 1,3,5-tris (2- (4-dodecyloxyphenyl) -Oxadiazol-5-yl-ethynyl) benzene, or 1,3,5-tris (2- (3,4,5-tris-dodecyloxyphenyl) -oxadiazol-5-yl-ethynyl Benzene, but is not limited thereto.

Preferred embodiments of the compound of the formula (1) include a liquid crystal display comprising a disc-shaped liquid crystal composed of the compound of the formula (1) and a disc-shaped liquid crystal composed of the compound of the formula (1).

The compound of formula 1 may be synthesized via any method known to those skilled in the art to which this invention belongs.

Scheme of the preparation of the compound of Formula 1 is shown in the following scheme.

Hereinafter, the synthesis step of the compound of Formula 1 will be described in detail, but the synthesis method of the compound of Formula 1 is not limited thereto.

Step 1:

4-hydroxy ethylbenzoate or garlic acid ethyl ester is reacted with chloro, bromo or iodoalkane having 6 to 22 carbon atoms under a base catalyst to synthesize the following Chemical Formula 2.

In the formula, R ₁ , R ₂ has the same meaning as defined in formula (1).

Compounds of formula (2) preferably include, but are not limited to, 4-hexyloxy ethylbenzoate, 4-dodecyloxy ethylbenzoate or 3,4,5, -tridodecyloxy-benzoic acid ethyl ester no.

Step 2:

After hydrolyzing the ethyl ester of Formula 2 with KOH as a catalyst, thionyl chloride is used to generate an acid chloride and reacted with hydrazine to obtain the following Formula 3.

In the formula, R ₁ , R ₂ has the same meaning as defined in formula (1).

The compound of formula 3 is preferably 4-hexyloxy-benzoic acid hydrazide, 4-dodecyloxy benzoic acid hydrazide or 3,4,5, -tridodecyloxy benzoic acid hydrazide Including but not limited to.

Step 3:

4-Bromo or 4-iodo benzoic acid is converted to an acid chloride using thionyl chloride, and then reacted with Chemical Formula 3 and refluxed with POCl ₃ to obtain Chemical Formula 4 below.

In the formula, R ₁ , R ₂ has the same meaning as defined in formula (1).

The compound of formula 4 is preferably 2- (4-bromo-phenyl) -5- (4-hexyloxy-phenyl) oxadiazole, 2- (4-bromo-phenyl) -5- (4- Dodecyloxy-phenyl) oxadiazole or 2- (4-bromo-phenyl) -5- (3,4,5-tris-dodecyloxy-phenyl) oxadiazole.

Step 4a:

The reaction obtained by reacting Formula 3 with 1,3,5-benzene tricarboxylic acid chloride under triethyl amine catalyst was refluxed with POCl ₃ to obtain Formula 1 wherein n is 0.

The compound of formula (1) obtained by this step is 1,3,5-tris (2- (4-hexyloxyphenyl) -oxadiazol-5-yl) benzene, 1,3,5-tris (2- ( 4-dodecyloxyphenyl) -oxadiazol-5-yl) benzene or 1,3,5-tris (2- (3,4,5, -tris-dodecyloxyphenyl) -oxadiazole-5- I) benzene, but not limited thereto.

Step 4b:

The reaction of Chemical Formula 4 with 1,3,5, -triethynyl benzene under Pd / Cu catalyst yields Chemical Formula 1 where n is 1.

The compound of formula 1 obtained by this step is 1,3,5-tris (2- (4-hexyloxyphenyl) -oxadiazol-5-yl-ethynyl) benzene, 1,3,5-tris ( 2- (4-dodecyloxyphenyl) -oxadiazol-5-yl-ethynyl) benzene or 1,3,5-tris (2- (3,4,5-tris-dodecyloxyphenyl) -oxa Diazol-5-yl-ethynyl) benzene, but is not limited thereto.

Example

The present invention is explained in more detail by the following examples, but the protection scope of the present invention is not limited by the examples.

Example 1: Preparation of 1,3,5-tris (2- (4-hexyloxyphenyl) -oxadiazol-5-yl) benzene

(1) Preparation of 4-hexyloxy ethylbenzoate

33.24 g (0.2 mol) of 4-hydroxy ethylbenzoate is dissolved in 100 ml of ethanol, and then 11.22 g (0.2 mol) KOH and a small amount of KI are added. Heat to 60 ^° C. with stirring, and then react for about 6 hours at reflux with the slow addition of 27.48 ml (0.2 mol) of 1-chlorohexane. After completion of the reaction, the resultant was added to excess distilled water, and extracted with ethyl acetate. After solvent removal, precipitate in hexane to afford 4-hexyloxy ethylbenzoate.

Yield: 82%

¹ H-NMR (CDCl ₃ , 300 MHz) 7.99 (d, 2H), 6.89 (d, 2H), 4.31 (q, 2H), 4.00 (t, 2H)

(2) Preparation of 4-hexyloxy-benzoic acid hydrazide

25.0 g (0.1 mol) of 4-hexyloxy ethylbenzoate obtained are suspended in a mixture of ethanol / water (7/3 volume ratio) and KOH is added in 2 molar times. The mixture is refluxed for 3 hours and then added to excess water. The neutralized solution is filtered to give a white solid which is completely dried and then dissolved in 10 ml of dichloromethane containing 7.3 ml of dionyl chloride. One drop of N, N'-dimethylformamide is added to the mixture and heated with stirring at 70 ^° C. for 2 hours. After the reaction is complete the mixture is cooled to 0 ° C. and the fully dried mixture is diluted with 15 ml of tetrahydrofuran. Thereafter, the diluted solution was added dropwise to a solution composed of 24 ml (0.5 mol) of hydrazine monohydrate and 20 ml of triethylamine simultaneously with high speed stirring. After stirring for about 20 minutes, the solution is diluted with excess tetrahydrofuran, and the resulting yellow salt is filtered off. After complete removal of the solvent, impurities are removed using a silica gel flash column using ethyl acetate. Complete removal of tetrahydrofuran yields 4-hexyloxy-benzoic acid hydrazide as a white solid.

Yield: 70%

¹ H-NMR (CDCl ₃ , 300 MHz) δ 7.72 (d, 2H), 6.90 (d, 2H), 5.99 (t, 2H).

(3) Preparation of 1,3,5-tris (2- (4-hexyloxyphenyl) -oxadiazol-5-yl) benzene

2.6 g (0.01 mol) of 1,3,5-benzene tricarboxylic acid chloride and 9.5 g (0.04 mol) of 4-hexyloxy-benzoic acid hydrazide (2a) were added to tetrahydrofuran and triethyl amine. After the reaction, the solution is diluted with an excess of tetrahydrofuran and the yellow salt is removed. The solid obtained is then refluxed in 20 ml of POCl ₃ to effect ring closure of oxadiazole. The solution is placed in cold water and neutralized. Thereafter, the mixture is extracted with dichloromethane to give 1,3,5-tris (2- (4-hexyloxyphenyl) -oxadiazol-5-yl) benzene.

Yield 45%.

¹ H-NMR (CDCl ₃ , 300 MHz) δ 9.02 (t, 3H), 8.15 (d, 6H), 7.08 (d, 6H), 4.07 (t, 6H) MS-FAB: m / z = 811 [ M ⁺ + H] (calcd. 810).

Example 2: Preparation of 1,3,5-tris (2- (4-dodecyloxyphenyl) -oxadiazol-5-yl) benzene

(1) Preparation of 4-dodecyloxy ethylbenzoate

A 4-dodecyloxy ethylbenzoate was obtained in the same manner as in Example (1) except that 4-hydroxy ethylbenzoate and 1-bromododecane were used.

Yield: 76%

¹ H-NMR (CDCl ₃ , 300 MHz) δ 7.99 (d, 2H), 6.89 (d, 2H), 4.31 (q, 2H), 4.00 (t, 2H).

(2) Preparation of 4-dodecyloxy benzoic acid hydrazide

In the same manner as in Example (2), 4-dodecyloxy benzoic acid hydrazide is obtained.

Yield: 68%

¹ H-NMR (CDCl ₃ , 300 MHz) δ 7.72 (d, 2H), 6.90 (d, 2H), 5.99 (t, 2H).

(3) Preparation of 1,3,5-tris (2- (4-dodecyloxyphenyl) -oxadiazol-5-yl) benzene

1,3,5-tris (2- (4-dodecyloxyphenyl) -oxadiazol-5-yl) benzene was obtained in the same manner as in Example (3).

Yield: 42%.

¹ H-NMR (CDCl ₃ , 300 MHz) δ 9.03 (s, 3H), 8.15 (d, 6H), 7.07 (d, 6H), 4.07 (t, 6H) MS-FAB: m / z = 1063 [ M ⁺ + H] (calcd. 1062).

Example 3: Preparation of 1,3,5-tris (2- (3,4,5, -tris-dodecyloxyphenyl) -oxadiazol-5-yl) benzene

(1) 3,4,5, -tridodecyloxy-benzoic acid ethyl ester:

51 g (0.3 mol) of gallic acid are suspended in 200 ml of ethanol under sulfuric acid catalyst. The solution is refluxed for 3 hours and then cooled. When poured into cooling water, a white solid (gallic acid ethyl ester) is obtained.

The obtained solid and 1-bromododecane were subjected to the same method as in (1) of Example 1 to obtain 3,4,5, -tridodecyloxy-benzoic acid ethyl ester.

Yield: 55%

¹ H-NMR (CDCl ₃ , 300 MHz) δ 7.24 (s, 2H), 4.33 (q, 2H), 3.99 (m, 6H).

(2) Preparation of 3,4,5, -tridodecyloxy benzoic acid hydrazide

A 3,4,5, -tridodecyloxy benzoic acid high was carried out in the same manner as in Example (2) except that 3,4,5, -tridodecyloxy-benzoic acid ethyl ester was used. Obtain drazide.

Yield: 79%

¹ H-NMR (CDCl ₃ , 300 MHz) δ 6.60 (s, 2H), 3.51 (m, 6H).

(3) Preparation of 1,3,5-tris (2- (3,4,5, -tris-dodecyloxyphenyl) -oxadiazol-5-yl) benzene

Except for using 3,4,5, -tridodecyloxy benzoic acid hydrazide in the same manner as in Example 1 (3), 1,3,5-tris (2- (3,4, 5, -tris-dodecyloxyphenyl) -oxadiazol-5-yl) benzene is obtained.

Yield: 31%

¹ H-NMR (CDCl ₃ , 300 MHz) δ 9.06 (s, 3H), 7.40 (s, 6H), 4.11 (m, 18H)

MS-FAB: m / z = 2 169 [ M ⁺ + H] (calcd. 2168).

Example 4: Preparation of 1,3,5-tris (2- (4-hexyloxyphenyl) -oxadiazol-5-yl-ethynyl) benzene

(1) Preparation of 2- (4-bromo-phenyl) -5- (4-hexyloxy-phenyl) oxadiazole

2.0 g (0.01 mol) of 4-bromo benzoic acid is suspended in dichloromethane (10 ml) containing 1.96 ml (0.02 mol) of dionyl chloride, and then a small amount of N, N-dimethylformamide is added thereto. Heat to 70 ^o C and stir for 2 h. Thereafter, the mixture is cooled to room temperature and then diluted with 15 ml of tetrahydrofuran. The solution is then added with 3.84 g (0.012 mol) of 4-hexyloxy-benzoic acid hydrazide to a tetrahydrofuran solution containing 20 ml of triethylamine with high speed stirring. After stirring for 20 minutes, the mixture is diluted with excess tetrahydrofuran and then the salt is removed and then the solvent is removed. A silica gel flash column using ethyl acetate is carried out with the obtained yellow solid. The obtained solid was dissolved in 15 ml of phosphorus oxychloride and refluxed for 3 hours. After cooling again, it is poured into cooling water, which is extracted with dichloromethane. The extract is then washed several times and dried thoroughly.

This is column chromatographed to give 2- (4-bromo-phenyl) -5- (4-hexyloxy-phenyl) oxadiazole.

Yield: 56%

¹ H-NMR (CDCl ₃ , 300 MHz) δ 8.03 (d, 2H), 8.01 (d, 2H), 7.01 (d, 2H), 7.67 (d, 2H), 4.04 (t, 2H).

(2) Preparation of 1,3,5-tris (2- (4-hexyloxyphenyl) -oxadiazol-5-yl-ethynyl) benzene

Under a nitrogen atmosphere, 7.0 g of 2- (4-bromo-phenyl) -5- (4-hexyloxy-phenyl) oxadiazole is suspended in 40 ml of triethylamine / pyridine (volume ratio 3: 1) at room temperature. 0.75 g of 1,3,5, -triethynyl benzene was added, followed by dissolution of CuI and PPh3 with a catalyst. The mixture is then heated to 60 ^° C. and 0.001 g of PdCl ₂ is added. After refluxing for 12 hours, it is immersed in cooling water. The solid obtained through the filter is dissolved in dichloromethane. After the solvent is completely removed, the residue is purified by column chromatography.

Yield: 54%

¹ H-NMR (CDCl ₃ , 300 MHz) δ 8.15 (d, 6H), 8.08 (d, 6H), 7.75 (s, 3H), 7.69 (d, 6H), 7.04 (d, 6H), 4.05 (t, 6H) MALDI / TOF (Reflector, Positive) 1112.

Example 5 Preparation of 1,3,5-tris (2- (4-dodecyloxyphenyl) -oxadiazol-5-yl-ethynyl) benzene

(1) Preparation of 2- (4-bromo-phenyl) -5- (4-dodecyloxy-phenyl) oxadiazole

A 2- (4-bromo-phenyl) -5- (4-dodecyloxy-phenyl was carried out in the same manner as in (1) of Example 4, except that 4-dodecyloxy benzoic acid hydrazide was used. ) Oxadiazole is obtained.

Yield: 79%

¹ H-NMR (CDCl ₃ , 300 MHz) δ 8.03 (d, 2H), 8.01 (d, 2H), 7.01 (d, 2H), 7.67 (d, 2H), 4.04 (t, 2H).

(2) Preparation of 1,3,5-tris (2- (4-dodecyloxyphenyl) -oxadiazol-5-yl-ethynyl) benzene

Except for using 2- (4-bromo-phenyl) -5- (4-dodecyloxy-phenyl) oxadiazole, it was carried out in the same manner as in Example 4 (2) to give 1,3,5-tris ( 2- (4-dodecyloxyphenyl) -oxadiazol-5-yl-ethynyl) benzene is obtained.

Yield: 24%

¹ H-NMR (CDCl ₃ , 300 MHz) δ 8.15 (d, 6H), 8.08 (d, 6H), 7.75 (s, 3H), 7.69 (d, 6H), 7.04 (d, 6H), 4.05 (t, 6H) MALDI / TOF (Reflector, Positive) 1363.

Example 6: Preparation of 1,3,5-tris (2- (3,4,5-tris-dodecyloxyphenyl) -oxadiazol-5-yl-ethynyl) benzene

(1) Preparation of 2- (4-bromo-phenyl) -5- (3,4,5-tris-dodecyloxy-phenyl) oxadiazole

Except using 3,4,5, -tridodecyloxy benzoic acid hydrazide, it carried out similarly to (1) of Example 4, and 2- (4-bromo-phenyl) -5- ( 3,4,5-tris-dodecyloxy-phenyl) oxadiazole is obtained.

Yield: 78%

¹ H-NMR (CDCl ₃ , 300 MHz) δ 8.01 (d, 2H), 7.68 (d, 2H), 7.03 (s, 2H), 4.05 (m, 6H).

(2) Preparation of 5-tris (2- (3,4,5-tris-dodecyloxyphenyl) -oxadiazol-5-yl-ethynyl) benzene

 In the same manner as in (2) of Example 4, except that 2- (4-bromo-phenyl) -5- (3,4,5-tris-dodecyloxy-phenyl) oxadiazole was used 5-tris (2- (3,4,5-tris-dodecyloxyphenyl) -oxadiazol-5-yl-ethynyl) benzene is obtained.

Yield: 49%

¹ NMR (CDCl ₃ , 300 MHz) δ 8.16 (d, 6H), 7.76 (s, 6H), 7.71 (d, 6H), 7.33 (s, 3H), 4.08 (m, 18H) MALDI / TOF (Reflector, Positive ) 2469.

Experimental Example

Hereinafter, the effects of the compounds of the present invention will be described with reference to experimental examples in which the properties of the novel nematic liquid crystal materials prepared in Examples 1 to 6 are measured.

Phase Behavior of Star Flat Mesogens with Temperature

Phase behavior of star-shaped mesogens using differential scanning calorimetry (DSC), polarized optical microscopy (POM), and X-ray diffractometer (XRD) Measured.

The transition temperatures of the compounds of Examples 1 to 6 were measured at a scan rate of 10 ^o C / min using an undivided scanning calorimeter. The measurement results are shown in Table 1 below.

Fig. 1 shows the results of incineration X-ray diffractometer measurement of 1,3,5-tris (2- (4-dodecyloxyphenyl) -oxadiazol-5-yl-ethynyl) benzene as a star-shaped disc-shaped mesogen And the wide-angle X-ray diffractometer measurement result (inset). The XRD results above show a typical X-ray diffraction pattern of disc-shaped nematic phases.

Fig. 2 incineration of 1,3,5-tris (2- (3,4,5-tris-dodecyloxyphenyl) -oxadiazol-5-yl-ethynyl) benzene, a star-shaped disc-shaped mesogen The X-ray diffractometer measurement result and the wide-angle X-ray diffractometer measurement result (insertion degree) are shown. The XRD results above show a typical X-ray diffraction pattern on hexagonal irregular columns.

FIG. 3 shows a polarized light microscope observation of 1,3,5-tris (2- (4-dodecyloxyphenyl) -oxadiazol-5-yl-ethynyl) benzene, which is a star-shaped disc-shaped mesogen. It shows a typical Schlieren texture on the type nematic.

Fig. 4 shows polarization of 1,3,5-tris (2- (3,4,5-tris-dodecyloxyphenyl) -oxadiazol-5-yl-ethynyl) benzene, a star-shaped disc-shaped mesogen. A microscopic view shows a typical mosaic texture on a hexagonal irregular column.

It can be seen from Table 1 and FIGS. 1 to 4 that both column and disc nematic phases, which are typical liquid crystal phases of a disc type liquid crystal, can be obtained from a star-shaped molecule different from the structure of a conventional disc type liquid crystal.

Figure 5 shows the optical properties of the resultant compounds of Examples 1 to 6, it can be seen from Figure 5 that the liquid crystal material of the present invention has a fully conjugated structure and exhibits a strong blue fluorescence at about 390 ~ 480 nm.

The novel disc-shaped liquid crystal compound of the present invention has excellent electron transportability and provides new application possibilities by electron transport rather than hole transport.

The novel disc-like compound of the present invention, unlike the conventional disc-like, is a simple C _3h -symmetric structure, that is, a star-type in which the rigid structure is substituted at the 1,3,5-position of the benzene core, and thus is easy to manufacture and purify There is an advantage.

The novel disc-shaped compounds of the present invention can implement columnar and nematic phases through chemical structure changes and can be applied to various applications of disc-shaped liquid crystals.

The novel disc-shaped compound of the present invention shows strong fluorescence by itself and can be used as a light emitting layer as well as an electron transport layer in a light emitting diode.

1 is a measurement of an X-ray diffractometer (XRD) of a disc-shaped liquid crystal composed of 1,3,5-tris (2- (4-dodecyloxyphenyl) -oxadiazol-5-yl-ethynyl) benzene The result is.

     FIG. 2 shows the X-ray rotation of a disc-shaped liquid crystal composed of 1,3,5-tris (2- (3,4,5-tris-dodecyloxyphenyl) -oxadiazol-5-yl-ethynyl) benzene It is a measurement result of season (XRD).

3 is a measurement result of a polarization microscope (POM) of a disc-shaped liquid crystal composed of 1,3,5-tris (2- (4-dodecyloxyphenyl) -oxadiazol-5-yl-ethynyl) benzene.

     4 is a polarization microscope (POM) of a disc-shaped liquid crystal composed of 1,3,5-tris (2- (3,4,5-tris-dodecyloxyphenyl) -oxadiazol-5-yl-ethynyl) benzene ) Is the measurement result.

5 is a measurement result of the optical properties of the resultant compound of Examples 1 to 6.

Claims (7)

Compound represented by the following formula (1). [Formula 1] (Wherein n is 0 or 1, R ₁ is-(CH ₂ ) _x CH ₃ , R ₂ is H or — (CH ₂ ) _x CH ₃ , and x represents an integer between 5 and 21).  The compound of claim 1, wherein x is 5, 7, 9, 11 or 15. A compound according to claim 1 wherein the compound of formula 1 is 1,3,5-tris (2- (4-hexyloxyphenyl) -oxadiazol-5-yl) benzene, 1,3,5-tris (2- ( 4-dodecyloxyphenyl) -oxadiazol-5-yl) benzene, 1,3,5-tris (2- (3,4,5, -tris-dodecyloxyphenyl) -oxadiazole-5- Yl) benzene, 1,3,5-tris (2- (4-hexyloxyphenyl) -oxadiazole-5-yl-ethynyl) benzene, 1,3,5-tris (2- (4-dodecyl Oxyphenyl) -oxadiazol-5-yl-ethynyl) benzene, or 1,3,5-tris (2- (3,4,5-tris-dodecyloxyphenyl) -oxadiazol-5-yl -Ethynyl) benzene. Comprising a compound of the formula (1), the disk-like liquid crystal material that can implement a column phase and nematic phase. A disk-shaped liquid crystal comprising a liquid crystal material according to claim 4, which can implement a columnar phase and a nematic phase. Blue-emitting fluorescent disk-type liquid crystal made of the liquid crystal material of claim 4. A liquid crystal display comprising the disc-shaped liquid crystal of claim 5 or 6, wherein the column phase and the nematic phase can be realized.