JP2003081903A - Fluorine-containing liquid crystal compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new fluorine-containing liquid crystal compound increasing thermal stability of a columnar phase and extending the temperature range. SOLUTION: This fluorine-containing liquid crystal compound has a substituent on a fluoroalkyl chain at least at one position of the 2-, 3-, 6-, 7-, 10- and 11-positions of a triphenylene skeleton [except a compound in which the substituent is OCO(CH2 )4 (CF2 )3 CF3 or OCH2 COOC2 H4 Cn F2n+1 (wherein, n is 6, 8 or 10)].

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a liquid crystal compound having a triphenylene skeleton.

[0002]

2. Description of the Related Art Conventionally, in the field of rod-shaped liquid crystals having a fluoroalkyl group,
Due to strong interactions based on fluoroalkyl groups,
It has been reported that the expression of SmA and SmB phases and the thermal stability of liquid crystals are strongly affected. It has also been clarified that the fluoroalkyl chain has a strong influence on the temperature range of the liquid crystal phase.

However, regarding the liquid crystal compound in which the thermal stability of the columnar phase is increased and its temperature range is widened,
unknown.

An object of the present invention is to provide a novel liquid crystal compound in which the thermal stability of the columnar phase is increased and its temperature range is widened.

[0005]

As a result of intensive studies, the present inventors have found that the triphenylene skeleton has 2-, 3-, and 6-positions.
It has been found that by having a specific substituent having a fluoroalkyl chain at at least one of the 7-position, the 7-position, the 10-position and the 11-position, the thermal stability of the columnar phase is increased and its temperature range is expanded, The present invention has been completed.

That is, the present invention is as follows.
A fluorine-containing liquid crystal compound is provided. Item 1. 2nd, 3rd, 6th, 7th of triphenylene skeleton
At least one of the tenth, tenth and eleventh positions,
Liquid crystal compound having a substituent having a fluoroalkyl chain
(However, when the substituent is -OCO (CH₂)_Four(CF₂)₃CF₃Well
Or -OCH₂COOC ₂H_FourC_nF_{2n + 1}(N is 6, 8 or
Is 10). ). Item 2. 2nd, 3rd, 6th, 7th of triphenylene skeleton
At least one of the tenth, tenth and eleventh positions,
O (CH₂)_m(CF₂)_nCF₃(In the formula, m is an integer of 0 to 10
And n is an integer of 0-10. ) Represented by full
Item 2. The liquid crystal according to item 1, which is bound with an oroalkyloxy group.
Compound. Item 3. General formula (1);

[0007]

[Chemical 3]

[0008] (wherein, R _{-O (CH 2) m (CF} 2) n CF 3
Indicates. m is an integer of 0-10 and n is an integer of 0-10. 4. The liquid crystal compound according to item 2, which is represented by Item 4. Item 4. The liquid crystal compound according to any one of items 1 to 3, which has a liquid crystal phase having a column structure. Item 5. General formula (1);

[0009]

[Chemical 4]

(In the formula, R is --O (CH ₂ ) ₃ (CF ₂ ) _n CF ₃
Indicates. n is 3 or 5. 4. The liquid crystal compound according to item 3, which is represented by

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The liquid crystal compound of the present invention comprises the 2-position, 3-position, 6-position, 7-position, 10-position and 1-position of a triphenylene skeleton.
A fluorine-containing liquid crystal compound having a substituent having a fluoroalkyl chain at at least one position of the 1-position. Wherein the substituent is _{-OCO (CH 2) 4 (CF} 2) 3 CF 3 or -
Compounds that are OCH ₂ COOC ₂ H ₄ C _n F _{2n + 1} (where n is 6, 8 or 10) are excluded.

Substituents having such a fluoroalkyl chain are the 2-position, 3-position, 6-position and 7-position of the triphenylene skeleton
It suffices that it is bonded to at least one of the 10th, 10th and 11th positions. A hydrogen atom, a hydroxyl group, an alkyloxy group or the like may be bonded to other positions.

The liquid crystal compound of the present invention shows a temperature transition type (thermotropic) liquid crystal.

[0014] As a substituent having a fluoroalkyl _{chain, -O (CH 2) m (} CF 2) fluoroalkyl group represented by _n CF ₃ is preferred. Here, m is an integer of 0-10, preferably an integer of 3-10. Also, n
Is an integer of 0 to 10, preferably an integer of 0 to 7.

The fluoroalkyl group represented by _{-O (CH 2) m (CF} 2) n CF 3 , as represented by the general formula (1), 2-position of the triphenylene skeleton, 3, 6
It is preferably attached at all positions, 7, 7, 10 and 11.

Among the above liquid crystal compounds, compounds having a liquid crystal phase having a column structure are preferable.

[0017] As the fluoroalkyl _{group, -O (CH 2) 3 (} CF 2) fluoroalkyl group represented by _n CF ₃ is preferred. Here, n is 3 or 5. Such a fluoroalkyloxy group represented by —O (CH ₂ ) ₃ (CF ₂ ) _n CF _{3 has all} of the 2-position, 3-position, 6-position, 7-position, 10-position and 11-position of the triphenylene skeleton. The liquid crystal compound bonded to the position has a liquid crystal phase having a column structure.

The fluorine-containing liquid crystal compound of the present invention is, for example,
It can be manufactured as follows.

That is, it is obtained by reacting 2,3,6,7,10,11-hexahydroxytriphenylene with a fluoroalkyl p-toluenesulfonate in the presence of sodium hydride in a solvent such as DMF. be able to. The reaction temperature is preferably 120 to 150 ° C. The reaction time is
15 to 22 hours are preferred.

After completion of the reaction, the target compound can be purified by a known method such as extraction, solvent removal, recrystallization and the like.

Since the liquid crystal compound of the present invention has a fluoroalkyl chain in the molecule, the thermal stability of the columnar phase is increased and its temperature range is expanded. As a result, the liquid crystal compound of the present invention can be expected to have an increased charge mobility due to the stabilization of the columnar structure, and is therefore expected to be used as a material having an optical / electronic function. For example,
By being used as a photoconductor, it can be applied to electrophotographic photoreceptor devices and the like.

Further, heat resistance, chemical resistance, weather resistance, surface characteristics (low surface tension, water / oil repellency, antifouling property, low friction property,
It is expected to be used as a material such as non-adhesiveness), optical characteristics (low refractive index, high transparency), electrical characteristics (high conductivity, high insulation), and gas selective permeability represented by contact lenses.

[0023]

EXAMPLES The present invention will be described in more detail below with reference to examples.

The reactions in Examples 1 and 2 were as follows:
It is expressed by the following formula.

[0025]

[Chemical 5]

Example 1 Preparation of 2,3,6,7,10,11-hexa [3- (perfluoro-n-butyl) propyloxy] triphenylene (when n = 3 in the above reaction formula) Sodium hydride ( 576 mg, 24.0 mmol),
Dry DMF (30 ml) and 2,3,6,7,10,11-hexahydroxytriphenylene (649 mg, 2.0 mmo
1) were sequentially added, and the mixture was stirred at room temperature under an argon atmosphere.
After 1.5 hours, 3- (perfluoro-n-butyl) propyl p-
Toluene sulfonate (6400 mg, 14.8 mmo
1) was added and the mixture was reacted at 130 ° C. for 17.5 hours. After allowing to cool, ice water was added, and the mixture was extracted with ether. The ether layer is 0.
It was washed with 5N-hydrochloric acid aqueous solution and saturated saline, and then the solvent was removed. The crude product was separated by column chromatography and recrystallized from hexane to obtain the desired product. Yield 84
0 mg, yield 22.3%. The analysis results are shown below. ¹ HNMR (CDCl ₃ , 500.0MHz) δ 2.21-2.28 (m, 2H), 2.37-2.5
1 (m, 2H), 4.31 (t, J = 5.8Hz, 2H), 7.82 (s, 1H). ¹⁹ FNMR (CDCl ₃ , 376.1MHz) δ -81.7 (t, J = 9.2Hz, 3F),- 11
5.0- -115.2 (m, 2F), -125.0 (s, 2F), -125.6 (t, J = 12.2H
z, 2F) .MS m / z = 1884 (calculated as C ₆₀ H ₄₂ F ₅₄ O ₆ 1884) .FTIR (KBr, cm ^-1 ) 1520, 1442, 1269, 1226, 1176, 1134,
1032, 722.

Example 2 Preparation of 2,3,6,7,10,11-hexa [3- (perfluoro-n-hexyl) propyloxy] triphenylene (when n = 5 in the above reaction formula) Sodium hydride ( 288 mg, 12.0 mmol),
Dry DMF (20 ml) and 2,3,6,7,10,11-hexahydroxytriphenylene (324 mg, 1.0 mmo
1) were sequentially added, and the mixture was stirred at room temperature under an argon atmosphere.
After 1.5 hours, 3- (perfluoro-n-hexyl) propyl p
-Toluene sulfonate (3730 mg, 7.0 mmo
1) was added, and the mixture was reacted at 130 ° C. for 21.5 hours. After allowing to cool, ice water was added, and the mixture was extracted with ether. The ether layer is 0.
It was washed with 5N-hydrochloric acid aqueous solution and saturated saline, and then the solvent was removed. The crude product was separated by column chromatography and recrystallized from acetone to obtain the desired product. Yield 27
0 mg, yield 10.9%. The analysis results are shown below. ¹ HNMR (CDCl ₃ , 500.0MHz) δ 2.20-2.28 (m, 2H), 2.36-2.5
0 (m, 2H), 4.30 (t, J = 5.8Hz, 2H), 7.81 (s, 1H). ¹⁹ FNMR (CDCl ₃ , 376.1MHz) δ -81.4 (t, J = 10.0Hz, 3F),- 1
14.8- -115.2 (m, 2F), -122.5 (s, 2F), -123.5 (s, 2F), -1
24.0 (s, 2F), -126.6- -126.9 (m, 2F) .MS m / z = 2484 (calculated as C ₇₂ H ₄₂ F ₇₈ O ₆ 2484) .FTIR (KBr, cm ^-1 ) 1520, 1442, 1266, 1236, 1191, 1146,
1034, 698.

Example 3 Investigation of liquid crystallinity The compounds produced in Examples 1 and 2 were examined by texture observation with a DSC and a polarizing microscope. The results are shown in Table 1. These compounds are liquid crystal compounds exhibiting a hexagonal columnar (Col _h ) phase.

[Table 1] Compound Phase transition temperature (° C) (Phase transition enthalpy (kJ / mol)) Example 1 Cr 117.0 Col _h 156.4 Iso (n = 3) (49.7) (3.67) Example 2 Cr 86.6 Col _h 180.2 Iso (n = 5) (45.7) (4.82) .

[0030]

The liquid crystal compound of the present invention is a novel liquid crystal compound in which the thermal stability of the columnar phase is increased and the temperature range is widened.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroshi Shimizu             1-83-1 Midorigaoka, Ikeda, Osaka Prefecture             AIST Kansai Center F-term (reference) 4H006 AA01 AA03 AB64 GP03 GP20                 4H027 BA16 BD01 BD02 DM03

Claims (5)

[Claims] 1. The triphenylene skeleton in the 2-position, 3-position and 6-position.
Position, 7-position, at least one position of the 10-position and 11-position, the liquid crystal compound having a substituent group having a fluoroalkyl chain (wherein the substituent is _{-OCO (CH 2) 4 (CF} 2) 3 CF
₃ or _{-OCH 2 COOC 2 H 4 C n} F 2n + 1 (n is 6, 8
Or is 10). ). 2. The 2-position, 3-position and 6-position of the triphenylene skeleton.
Position, 7-position, at least one position of the 10-position and _{11-position, -O (CH 2) m (} CF 2) n CF 3 ( where, m is 0-10
Is an integer of 0, and n is an integer of 0-10. The liquid crystal compound according to claim 1, wherein a fluoroalkyloxy group represented by the formula (1) is bonded. 3. A compound represented by the general formula (1): (Wherein, R .m showing a _{-O (CH 2) m (CF} 2) n CF 3 is an integer of 0, n is an integer of 0-10.)
The liquid crystal compound according to claim 2, represented by: 4. The liquid crystal compound according to claim 1, which has a liquid crystal phase having a column structure. 5. A compound represented by the general formula (1): (Wherein, R _{-O (CH 2) 3 (CF} 2) .n showing an _n CF ₃ is 3 or 5.) The liquid crystal compound of claim 3 represented by.