JPH0352882A - Liquid crystal compound and use thereof - Google Patents

Abstract

NEW MATERIAL:A compound containing an optically active gamma lactone ring shown by formula I (R<1> and R<2> are 1-15C alkyl or 2-15C alkenyl; A is single bond or -O-; n is 0 or 1; * is asymmetric carbon atom). EXAMPLE:A compound shown by formula II. USE:A display element and electro-optical element. PREPARATION:1mol cyclohexylacetic acid derivative shown by formula III is reacted with 2mol lithium diisopropylamide at -30 deg.C to 10 deg.C and successively with an optically active epoxy compound shown by formula IV at -78 deg.C to room temperature to give an addition compound shown by formula V. This compound is subjected to intramolecular dehydration reaction in the presence of an acid catalyst such as sulfuric acid in a solvent such as benzene or toluene.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a novel liquid crystal compound that can be used in display elements or electro-optical elements.

The liquid crystal compound referred to in the present invention includes not only a substance whose liquid crystal state can be observed by itself, but also a compound which is useful as a component of a liquid crystal composition even if it itself does not exhibit a liquid crystal phase.

《Prior art and problems to be solved〉 Liquid crystals have come to be widely used as a display material, but currently the only display method is TN (Twisted).
d Nesatic) type is generally adopted.

This TN display method has advantages such as low power consumption and light-receiving type that does not cause eye fatigue, but since the drive is basically based on the anisotropy of dielectric constant, its power is weak and the response speed is low. It has the disadvantage of being slow, which limits its application to fields where high-speed response is required.

Ferroelectric liquid crystal was developed in 1975 by R. B. Meyer
It was first discovered by J. Ph.
ysique, 36, L-69 (1975))
Since this device uses a relatively large force derived from spontaneous polarization as the driving force, it has an extremely fast response speed and has excellent memory properties, and is attracting attention as a new display element. The condition for liquid crystal to exhibit ferroelectricity is that it must exhibit chiral smectic C phase (SIIlc phase), and for this reason it must contain asymmetric carbon in the molecule. It is necessary to have a dipole moment in the direction.

Ferroelectric liquid crystal HOBA}fB synthesized by Heyer et al.
Although C has the following structure and satisfies the above conditions, it is chemically unstable because it contains a Schiff base, and its spontaneous polarization is as small as 3×10 −90 /m. Since then, many ferroelectric liquid crystal compounds have been synthesized, but one that responds at a sufficiently high speed has not yet been found, and therefore has not been put into practical use.

Comparing these conventional ferroelectric liquid crystal compounds, for example, DOBA-1-MBC, in which the asymmetric carbon atom of DOBAMBC is one position closer to the carbonyl group, has a spontaneous polarization of 5x10-''8C/d; It is larger than DOBAHBC.This is because the positions of the asymmetric carbon and the dipole, which are important factors for the appearance of ferroelectricity, are close to each other, so the free rotation of the dipole part of the molecule is suppressed, and the dipole is This is thought to be due to the improved orientation.In other words, the asymmetric moiety acts to restrict the free rotation of molecules, and in most conventional ferroelectric liquid crystal compounds, the asymmetric moiety is in a straight chain. It is thought that satisfactory spontaneous polarization and high-speed response could not be obtained because the free rotation of the molecules could not be completely suppressed and the dipole portion could not be fixed.

(Means for Solving the 'IIl Problem) The present invention provides a structure in which an asymmetric moiety is directly connected to a five-membered ring lactone as a means for suppressing the free rotation of the dipole part of a conventional ferroelectric liquid crystal compound. The present invention provides a novel liquid crystalline compound that restrains rotation and has chemically stable ferroelectricity.

The novel compound according to the present invention has the general formula (I>(formula (I>in which R
1 and R2 are each independently an alkyl group having 1 to 15 carbon atoms or a 7-rukenyl group having 2 to 15 carbon atoms, A is a single bond or -0-, n is O or 1, and the symbol * is an asymmetric carbon atom. The present invention relates to a compound having an optically active γ-lactone ring represented by the following formula, a liquid crystal composition containing at least one of the compounds, and an electro-optical element using the composition.

In R1 and R2 of the above general formula (I), examples of the alkyl group include methyl, ethyl, n-propyl,
n-butyl, n-bentyl, n-hexyl, n-
heptyl, n-octyl, n-nonyl, n-decyl, n
-Undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, isoprovil, t-butyl, 2-methylpropyl, 1-methylpropyl, 3
-Methylbutyl, 2-methylbutyl, 1-methylbutyl, 4-methylpentyl, 3-methylbentyl, 2-methylbentyl, 1-methylbentyl, 5-methylhexyl, 4-methylhexyl, 3-methylhexyl, 2-methylhexyl , 1-methylhexyl, 6-methylheptyl, 5-methylheptyl, 4-methylheptyl, 3-methylheptyl, 2-methylheptyl, 1-methylheptyl, 7-methyloctyl, 6-methyloctyl, 5-methyloctyl, 4 -methyloctyl, 3-methyloctyl, 2-methyloctyl, 1-methyloctyl, 8-methylnonyl, 7-methylnonyl, 6-methylnonyl,
Examples include groups such as 5-methylnonyl, 4-methylnonyl, 3-methylnonyl, 2-methylnonyl, 1-methylnonyl, 3,7-dimethyloctyl, and 3,7.11-trimethyldodecyl. Further, examples of alkenyl groups include vinyl, brobenyl, and the like. butenyl, pentenyl,
Hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl. Linear ones such as pentadecenyl, 1-
Examples thereof include branched alkenyl groups such as methylpropenyl, 2-methylprobenyl, 3-methylbutenyl, and 4-methylbentenyl.

The above-mentioned novel compound according to the present invention has a carbonyl group as a moiety having a dipole moment for generating ferroelectricity located inside a 5-membered ring, and a subirocyl hexyl group is roughly substituted on the 5-membered ring. This makes it possible to orient the dipole portion as a whole in one direction, increasing spontaneous polarization and realizing high-speed response. The liquid crystal compound (I) of the present invention has two types of cis and trans isomers. These have a structure that meets the purpose of suppressing the free rotation of the dipole part, so
They are useful as liquid crystalline compounds whether they are used alone or as a mixture.

The compound represented by the general formula (I) according to the present invention can be produced by the method shown below. however,
In the reaction formula below, the symbols R1, R2A, n and * represent the same meanings as the symbols R1, R2A, n and * in general formula (I)77).

(n) (II) (TV) In the above reaction, a cyclohexyl acetic acid derivative (It>) synthesized by a known method is mixed with twice the molar amount of lithium diisobrobyl aide (LDA) at a temperature of -30 to 10°C. The adduct compound (IV} can be obtained by reacting with 0.3 to 3 times the mole of optically active epoxy compound (III) at -78°C to room temperature.This compound (IV) can be reacted with When an intramolecular dehydration reaction is carried out in a solvent such as benzene or toluene in the presence of an acid catalyst such as sulfuric acid, hydrochloric acid, or para-1-luenesulfonic acid, the optical activity γ- of the general formula (I>)
A lactone derivative is obtained.

In the optically active epoxy compound (III>) used in the above reaction, a compound (III)-(1) in which A is a single bond can be obtained by the following reaction.

(III)-(1) (In the above reaction, the symbols R1 and * represent the general formula (I)
(X represents a halogen atom) In other words, a Grignard reagent is synthesized by the reaction of an alkyl halide or an alkenyl halide (RIX) with magnesium, and then a halogen Optically active epoxy compound (III)-(1) can be obtained by reacting with optically active shrimp chlorohydrin in the presence of copper chloride (CuX).

In the optically active epoxy compound (III), A is -0
- Compound (III> - (2>) can be obtained by the following reaction.

(III) - (2) <In the above reaction, R? The signs of and * represent the general formula (I>
(represents the same meaning as the R1 and * symbols) That is, alcohols (R10) and optically active epichlorohydrin are reacted in the presence of an acid catalyst to combine chlorohydrin ether (V), The synthesis can then be carried out by a two-step method in which ring closure is performed with an alkali, or a one-step method in which the alcohol is reacted with optically active shrimp chlorohydrin and a base in the presence of a quaternary ammonium salt catalyst.

Moreover, the optically active epoxy compound (III) -(1
) is a method in which the reaction between olefin and air is carried out using microorganisms.

The above-mentioned optically active shrimp chlorohydrin is of high purity, and the R form is disclosed in Japanese Patent Application Laid-Open No. 61-132199 filed by the present applicant.
@Publication and JP-A-62-6697@Publication method,
Similarly, the S-form obtained by the method described in the specification of Japanese Patent Application No. 63-284881 can be used.

In the present invention, if a racemic compound is used as the epoxy compound (I[I), the final target product, the γ-lactone derivative (I), can be obtained as a racemic compound. This racemic compound can be added to other optically active liquid crystal compounds to adjust their helical pitch.

The compound of the above general formula (i>) of the present invention can be made into a liquid crystal composition by mixing at least one of the compounds with another ferroelectric liquid crystal, a non-chiral liquid crystal, or a mixture thereof. .

As the other ferroelectric liquid crystals mentioned above, all ferroelectric liquid crystals including those conventionally known can be applied, and as non-chiral liquid crystals, liquid crystals that do not have asymmetric carbon atoms and that after mixing can be used. Any material may be used as long as it exhibits a smectic C phase.

Specific examples of the above-mentioned non-chiral liquid crystal include compounds represented by the following formula (J).

R3-w+{E←-7-K4→yL- (J) (In formula (J), E, F, and G each represent a six-membered ring independently selected from The atom may be substituted with a halogen atom, a cyano group, or a ditro group. a1b is 0, 1 or 2, C is 1 or 2, and a + b + c = 2 to 4. W, M is a single bond or represents a group selected from O - O - C - C - 10 days 20 - and OCR2 -. When a = 0, K
represents a single bond, and when bo, L represents a single bond.

K. when a or b is not O. Each L is independently a single bond, or -OC21-CH2-C2110 days=N-1N-CH-, -C days=C days0 -C3C- -C CH-C-0- and R3 and R4 represent an alkyl group having 1 to 15 carbon atoms) A transparent electrode is attached to the liquid crystal composition of the present invention, and polyethylene,
Enclosed in two glass plates whose surfaces have been treated with polyester, nylon, polyvinyl alcohol, polyimide, etc.
A birefringence mode and host-to-guest mode liquid crystal cell provided with a polarizer can be used as a display element or an electro-optical element.

The compound of the general formula (I>) of the present invention has good stability against heat and light, and a liquid crystal composition containing this compound has excellent properties as a ferroelectric liquid crystal.

Furthermore, a liquid crystal composition in which the compound is added to a nematic liquid crystal can be used for the following purposes.

(1) TN to suppress the occurrence of reverse domain
Liquid crystal composition added to type and STN type liquid crystal.

(2) Display element using cholesteric-nematic phase transition effect (J.J.Wysoki, A.^daRI
s and W.S. Haas: Phys. Rev. L
ett. , 20.1024 (1968)).

(3) Display element using White Tiller type guest-host effect (D.L.White and G.N.T.
aylor ;J. ^DDl. Phys. ,45.47
18 (1974)).

(4) immobilizing the cholesteric phase in the matrix;
Notch filters and bandpass filters (F.J. Kahn: Appl.Ph.
ys. Lett. , 18, 231 (1971)
).

(5> Circular polarization beam splitter using the circular polarization characteristics of the cholesteric phase (S. D. Jacob, SP
I.E. 37. 98 (1981)).

(Example) In each of the following examples, the cis and trans representations of the optically active compound represented by the general formula (I>) of the present invention are expressed as follows.

The phase transition temperature described in the examples was determined by DSC and polarized light microscopy. In addition, the symbols shown in the phase transition temperature section represent the following phases.

C: Crystalline phase SIA; Smectic A phase SmC": Chiral smectic C phase I; Isotropic liquid phase Formula (III> Combination of compounds) Synthesis Example 1 (S) Combination of monoallyl glycidyl ether or stirred and refluxed (S) shrimp chlorohydrin (chemical purity 98.5% or more, optical purity 99% or more ([α] g = +34.0°, C
= 1.2, methanol) ) 19.54g and allyl alcohol 20! A solution of f1i was added dropwise over 20 minutes, and the mixture was roughly stirred and refluxed for 20 minutes. 10 to 15 times the reaction solution
After cooling to ℃, methanol solution of 25.2 g of caustic potash 13
0Rl was added dropwise and stirred for 10 minutes. The reaction solution was transferred to saturated brine, the product was extracted with methylene chloride, and the product was rectified to obtain (S) monoallyl glycidyl ether9. 51 g was obtained.

[α]l -9.24゜ (C= 1.075, C
mouth2Ci2) NMR (CDC1:s) δ:2.61 (1 day, dd) 2.80
(IH.t) 3.16 (1 day, m) 3.40 (1 mouth, dd) 3.73 (IH, dd) 4.05
(1 mouth, m) 5.20 (1 day, d> 5.29 (IH, d>5.91
(1 mouth, m) Example 1 3 ml of a 15% n-butyllithium hexane solution was added dropwise to a solution of 505 mg of diimpylamine and 10 d of tetrahydrofuran cooled to -78°C, and the temperature was gradually raised to 0°C. Stir for 30 minutes. A solution of 695 lRg of trans-4-(p-n-octylphenyl)cyclohexanecarboxylic acid and 3d of 7 runs of tetrahydride was added dropwise to this reaction solution and stirred for 1 hour. The reaction solution -
Cool to 78°C and use commercially available (R) = 1,2-epoxy hebutane ([α cotube + 15.0° (neat)) 274
A solution of na and tetrahydride 7 runs 2nd was added dropwise.

The temperature of the reaction solution was gradually raised to a boiling point, water was added after stirring for 6 hours, the solution was acidified with hydrochloric acid, and the raw material was extracted with chloroform. Dry benzene and a catalytic amount of WL acid were added to the extract, and the mixture was heated and stirred for 6 hours while allowing the penzene to flow out little by little.

After cooling, benzene was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography to obtain γ shown by the chemical formula below.
- Lactone derivative cis form and 1 to lance form each 4
43m(] and 55mg were obtained.

[α]萱 +9.28゜ (c=1.OD7 phase transition temperature Cday2Ci2) IR (KBr) 1760cm-IIH-NMR
(CDα3) δ: 0.8 ~ 1.0 (6 mouths, m) 1.2 ~ 1
．． 8 (25 days, m) 1.8 - 2.2 (4 days, m) 2.4 - 2.6 (4 units, m) 4.44 (1 day, m) 7.10 (2 days, d ) 7.17 (2 ports, d) 13C-NMR (CDC13) δ: 13.96, 14.10, 22.52
,29.17 ,29.27 ,29.45 ,3
1.58, 31.91, 34.29, 35,
90, 42.21, 43.19, 126.8
5, 128.31, 140.61, 22.68, 29.49, 34.6B, 44.86, 143. 90, 24.98, 31.54, 35.59, 76.83, 179. 77 [α Koda + 25.38° Phase transition temperature (C = 1.120, C day 2c12) C7 snoring → I I R (KB r) 1756 cm-11 days-NMR (CDC13) δ: 0.8 ~ 1.0 (6 mouths, m) 1.2~
2.1 (29 days, m) 2.4-2.6 (4 days, m) 4.42 (1 mouth, m) 7.11 (4 mouths, S) "C-NMR (CDC13) δ: 13 .96, 14.10, 22.53
, 22.66 , 25.05 , 29.26 ,
29.42, 29.49, 29.91, 3
0.00 , 31.53 , 31.57 , 31.
66, 31.89, 34.75, 35.5B
, 36.03 , 38.76 , 42.75
, 44.83 , 77.62 , 126.49,
128.43, 140.139, 143.55,1
81.85 Example 2 505 ffl diimpyramine cooled to -78°C
g and 15% n- in a solution of 10 ml of tetrahydrofuran.
3d of a hexane solution of butyl lithium was added dropwise, the temperature was gradually raised to 0° C., and the mixture was stirred for 30 minutes. A solution of 446 mg of trans-4-n-pentylcyclohexanecarboxylic acid and 5 d of tetrahydrofuran was added dropwise to this reaction solution and stirred for 1 hour. The reaction solution was cooled to -78°C, and commercially available (R>-1,2-epoxytridecane ([α]
A solution of 446 mg of V+9.8° (neat) and 1 d of tetrahydrofuran was added dropwise. After the temperature of the reaction solution was gradually raised to room temperature and stirred for 6 hours, water was added, and the mixture was further acidified with hydrochloric acid and the raw material was extracted with chloroborm. Dry benzene and a catalytic amount of fIft acid were added to the extract, and the benzene was heated and stirred for 6 hours while gradually flowing out. After cooling, the benzene was distilled off under reduced pressure, and the residue was purified by silica gel force column chromatography to obtain the following chemical formula. γ−
583 mg of lactone derivative was obtained.

+13.08° phase transition temperature in cis form [α] (C=1.063, c6 Wataruhi→I 1 mouth-NMR (CDc!3) δ: 0.8-0.9 1.2-2,0 2.12 4.40 (6 ports, m) (38H, m> (1 day, dd) (1 port, m) C port 2α2> 13C-NMR (CD(j!3) δ: 14.1i, 22 .70, 25.36
, 26.86 , 27.57 , 29.37 ,
29.42, 29.52, 29.56, 2
9.64, 31.95, 32.15, 32.
22, 33.09, 35.06, 35.71
, 35.99 , 43.33 , 43.53
, 76.95, 180.43 Example 3 A hexane solution of 15% n-butyllithium was added to a solution of 1.01 g of diisopropylamine and 20 d of tetrahydrofuran cooled to -78°C. IJ1 was added dropwise, the temperature was gradually raised to 0° C., and the mixture was stirred for 30 minutes. A solution of 1.39 g of trans-4-(1)-n-octylphenyl)cyclohexanecarboxylic acid and 8 m of tetrahydrofuran was added dropwise to this reaction solution and stirred for 1 hour. The reaction solution was cooled to -78°C, and a solution of 627 mg of (S) monoallyl glycidyl ether synthesized in Synthesis Example 1 and tetrahydrofuran 2Id was added dropwise. After the temperature of the reaction solution was gradually raised to room temperature and stirred for 6 hours, water was added to make the mixture acidic with salt M, and the raw material was extracted with chloroform. Dry benzene and a catalytic amount of sulfuric acid were added to the extract, and the mixture was heated and stirred for 6 hours while allowing the benzene to flow out little by little. After cooling, benzene was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography to obtain 109 mg and 3 mg of the cis and trans forms of T-lactone derivatives represented by the following chemical formulas, respectively.
Obtained 0 mg.

[α]τ -9.93° (C-1.007, C day 2α2) Phase transition temperature 1-row NMR (CDCi3) δ: 0.8-1.0 (3rd, 1.2-2.6 ( 25th, 3.58 (2H, 4.05 (2H, 4.62 (1st, 5.2-5.4 (2 mouths, 5.8-6.0 (1st, m) 7.10 ( 2 days, d) 7.18 (2 shares, d) DC-NMR (CDCi3) δ: 11.54, 23.11, 29.54
, 29.88 , 29.92 , 31.97 , 3
4.98, 36.02, 40.89, 71.
98, 72.95, 75.81, 128.7
5, 134.71, 141.71, trans form 29.68, 29.70, 32, 33, 34.94, 42.14, 43.52, 117.88, 127.28, 144.26, 179. 76 Phase transition temperature 1-NMR (CDCi3) δ2 0.8-1.0 (31-1.1.2-2.6
(25 mouths, 3.60 (2 days, 4.06 (2H, 4.60 (1 day, m) 5.2~5.4 (2 mouths, m) 5.8~6.0 (1 eye, m) 7.26 (4th day, S) Example 4 The T-lactone derivative represented by the following chemical formula obtained in Example 2 and the compound represented by the following chemical formula were mixed at a ratio of 1:19 (weight). A liquid crystal composition was obtained.The phase transition temperature of this composition was as follows.

In addition, as a result of measuring the response speed of this composition, it was found that 30
A high-speed response of 0 μSec (45°C) was obtained.The response speed was measured by enclosing the above composition in a 2 m thick cell treated with an alignment agent and using a VD-0
It was determined from the change in transmitted light intensity when a voltage of =20V was applied. A PET film was used as the baser, a polyimide film was used as the alignment agent, and an ITO electrode was used as the electrode, and the rubbing was performed in parallel.

(Effects of the Invention) The novel liquid crystal compound according to the present invention has better stability against heat and light than conventional liquid crystal materials, is chemically stable, and has excellent properties as a ferroelectric liquid crystal. This provides a liquid crystal material with extremely fast response speed.

Claims (4)

[Claims] (1) General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In formula (I), R^1 and R^2 are each independently an alkyl group having 1 to 15 carbon atoms or a carbon number A compound having an optically active γ-lactone ring represented by 2 to 15 alkenyl groups, A is a single bond or -O-, n is 0 or 1, and the symbol * represents an asymmetric carbon atom. (2) The compound according to claim 1, wherein the compound of general formula (I) is a racemate. (3) A liquid crystal composition containing at least one of the compounds according to claim 1 or 2. (4) An electro-optical element using the liquid crystal composition according to claim 3.