KR102142128B1 - Surface energy controlled photoresponsive chiral dopants for cholesteric liquid crystal composition - Google Patents

Abstract

The present invention relates to a chiral dopant compound, a liquid crystal composition comprising the same, and an improved use thereof, and more specifically, from a photosensitive chiral dopant having a controlled surface energy, a liquid crystal composition comprising the same, or efficiency in various applications using the same Regarding improvement, the chiral dopant compound represented by Chemical Formula 1 of the present invention can be modified to achieve excellent compatibility with various hosts depending on the purpose, and may exhibit excellent optical properties even at a small concentration. , It is possible to implement a cholesteric liquid crystal, and further, useful effects such as efficiency improvement in products such as various optical elements, displays, and sensors are achieved.

Description

Surface energy controlled photoresponsive chiral dopants for cholesteric liquid crystal composition}

The present invention relates to a chiral dopant compound, a liquid crystal composition comprising the same, and an improved use thereof, and more specifically, from a photosensitive chiral dopant having a controlled surface energy, a liquid crystal composition comprising the same, or efficiency in various applications using the same Improvement, etc.

Cholesteric liquid crystal (CLC) is a liquid crystal composition comprising a periodic twisting structure (spiral structure), in the presence of a chiral dopant, the direction of the nematic liquid crystal is rotated along a vertical axis.

The helical structure creates a photonic bandgap as the refractive index is periodically adjusted along the helical axis. When the spiral pitch is similar to the wavelength of visible light, CLC exhibits a structural color because light of the same handedness is selectively reflected in the bandgap. The structural color is controlled by external stimuli such as temperature, electric field, light, and mechanical stress to produce promising CLCs for various photonic applications, including reflective-mode displays, colorimetric sensors, and anti-counterfeiting materials. can do.

The helical pitch of the cholesteric liquid crystal is determined by the chiral dopant used. At this time, the helical pitch is determined by the interaction with the nematic liquid crystal used.

As new application fields of cholesteric liquid crystals continue to be developed as well as existing display application, development of cholesteric liquid crystal compositions suitable for each application is also required. Depending on the use of the cholesteric liquid crystal composition, it is necessary to develop a dopant having excellent compatibility with the host liquid crystal to be introduced into various host liquid crystals.

Thus, the present invention prevents the use of excessive dopant, while maintaining a high helical twisting power (HTP) in a variety of host liquid crystals, while having sufficient compatibility with the host, and also the dopant is a host While not in search of a method for preventing the degradation of the efficiency of the cholesteric liquid crystal itself generated from problems such as being incompatible with, for example, a dopant being precipitated, each of the new dopant compounds provided in the present invention After confirming that it was properly modified to have excellent compatibility with the host, the present invention was completed.

US 2014/0117284 A1

An object of the present invention is to provide a chiral dopant compound having a controlled surface energy, which is excellent in compatibility with various host liquid crystals and can change optical properties of a cholesteric liquid crystal in response to light.

Another object of the present invention is to provide a method for preparing the chiral dopant compound.

Another object of the present invention is to provide a nematic or cholesteric liquid crystal composition comprising the chiral dopant compound.

Another object of the present invention is to provide a chiral anisotropic polymer obtained by polymerizing the chiral dopant compound or the nematic or cholesteric liquid crystal composition in the form of a thin film in its orientation.

Another object of the present invention is to provide an optical sensor comprising the nematic or cholesteric liquid crystal composition, or the chiral anisotropic polymer.

In order to achieve the above object,

In one aspect of the invention,

Chiral dopant compounds represented by Formula 1 below, or stereoisomers thereof, are provided:

[Formula 1]

(In the above formula 1,

X ¹ and X ² are each independently N or CH,

Y ¹ and Y ² are each independently N or CH,

,

,

,

,

,

, 또는

이고, 및L ¹ and L ² are each independently

,

,

,

,

,

, or

Is, and

R ¹ and R ² are each independently substituted or unsubstituted C ₁ -C ₂₀ alkyl, substituted or unsubstituted C ₁ -C ₂₀ alkoxy, or -[(CH ₂ ) _a -O-(CH ₂ ) _b ) _m-

When one of R ¹ and R ² is unsubstituted alkyl, the other is not unsubstituted alkyl,

Here, the substituted alkyl or the substituted alkoxy is substituted with one or more substituents selected from the group consisting of halogen, hydroxy, oxo (=O), and amino,

The a and b are each independently 0 to 5 is an integer, when at least one of a and b is 0, the other is not 0, and

The main chain carbon of -[(CH ₂ ) _a -O-(CH ₂ ) _b ) _m -is optionally one or more substituents selected from the group consisting of halogen, hydroxy, oxo (=O), and amino Can be substituted with).

In addition, in another aspect of the invention,

As shown in Scheme 1 below,

Preparing a compound represented by Chemical Formula 2 from a compound represented by Chemical Formula 3 (step 1); And

A method for preparing a compound represented by Formula 1 of claim 1 is provided, comprising: preparing a compound represented by Formula 1 from a compound represented by Formula 2 (step 2).

[Scheme 1]

(In Scheme 1 above,

X ¹ , X ² , Y ¹ , Y ² , L ¹ , L ² , R ¹ , and R ² are as defined in claim 1).

Furthermore, in another aspect of the invention,

A nematic or cholesteric liquid crystal composition is provided, comprising a chiral dopant compound represented by Chemical Formula 1, or a stereoisomer thereof.

In addition, in another aspect of the invention,

A chiral anisotropic polymer obtained by polymerizing a chiral dopant compound represented by Chemical Formula 1, or a stereoisomer thereof, or the nematic or cholesteric liquid crystal composition in the form of a thin film in its orientation state is provided.

Furthermore, in another aspect of the invention,

An optical sensor comprising the nematic or cholesteric liquid crystal composition or the chiral anisotropic polymer is provided.

The chiral dopant compound represented by Chemical Formula 1 of the present invention can be modified to achieve excellent compatibility with various hosts depending on the purpose, and as a result, cholesteric liquid crystals that may exhibit excellent optical properties even at a small concentration. It is possible to implement, and further useful effects such as improving efficiency in products such as various optical elements, displays, and sensors are achieved.

1 is a photograph showing the contact angle of water or diiodomethane to the chiral dopant compounds prepared in Examples 1, 3 and Comparative Examples coated on a glass substrate.

Hereinafter, the present invention will be described in detail.

The following description is provided to help the understanding of the invention, and the present invention is not limited to the contents of the following description.

In one aspect of the invention,

Chiral dopant compounds represented by Formula 1 below, or stereoisomers thereof, are provided:

[Formula 1]

(In the above formula 1,

X ¹ and X ² are each independently N or CH,

Y ¹ and Y ² are each independently N or CH,

,

,

,

,

,

, 또는

이고, 및L ¹ and L ² are each independently

,

,

,

,

,

, or

Is, and

R ¹ and R ² are each independently substituted or unsubstituted C ₁ -C ₂₀ alkyl, substituted or unsubstituted C ₁ -C ₂₀ alkoxy, or -[(CH ₂ ) _a -O-(CH ₂ ) _b ) _m-

When one of R ¹ and R ² is unsubstituted alkyl, the other is not unsubstituted alkyl,

Here, the substituted alkyl or the substituted alkoxy is substituted with one or more substituents selected from the group consisting of halogen, hydroxy, oxo (=O), and amino,

The a and b are each independently 0 to 5 is an integer, when at least one of a and b is 0, the other is not 0, and

The main chain carbon of -[(CH ₂ ) _a -O-(CH ₂ ) _b ) _m -is optionally one or more substituents selected from the group consisting of halogen, hydroxy, oxo (=O), and amino Can be substituted with).

In one embodiment of the invention,

The compound represented by Formula 1, wherein R ¹ and R ² are each independently C ₁ -C ₂₀ alkyl substituted with halogen, or -(CH ₂ OCH ₂ ) _n -CH ₂ OCH ₃ (where n Is an integer from 0 to 20)

When one of R ¹ and R ² is unsubstituted alkyl, the other may be a non-substituted alkyl, chiral dopant compound, or stereoisomer thereof.

In another embodiment of the invention,

The compound represented by Chemical Formula 1 may be a chiral dopant compound wherein X ¹ , X ² , Y ¹ , and Y ² are N, or a stereoisomer thereof.

In another embodiment of the invention,

인 키랄 도펀트 화합물, 또는 이의 입체 이성질체일 수 있다..In the compound represented by Chemical Formula 1, L ¹ and L ² are

Phosphorous chiral dopant compounds, or stereoisomers thereof.

In another embodiment of the invention,

The chiral dopant compound represented by Chemical Formula 1 may be a compound selected from the group consisting of the following, or a stereoisomer thereof.

,

,

,

, 및

.

,

,

,

, And

.

In another aspect of the invention,

The chiral dopant compound represented by Chemical Formula 1 or a stereoisomer thereof may be photosensitive or thermally sensitive.

In one embodiment of the invention,

The chiral dopant compound represented by Chemical Formula 1 is photosensitive.

In another aspect of the invention,

The chiral dopant compound represented by Chemical Formula 1 may be a chiral dopant compound having a surface energy of 20-50 dyne/cm, 20-40 dyne/cm, 20-30 dyne/cm, or a stereoisomer thereof. .

In one aspect of the invention,

It can be understood that the dopant compound provided above, or the stereoisomer thereof, is a compound according to Formula 1, modified according to the characteristics of the target host, so as to have excellent compatibility with various hosts.

In one embodiment of the invention,

The compound represented by Formula 1 may be a compound independently selecting the R ¹ and R ² moieties according to the characteristics of the host.

In another embodiment of the invention,

If the applied host property is hydrophilic, it is preferable that the dopant for this is also hydrophilic, for example, at least one of the R ¹ and R ² moieties is a compound of -(CH ₂ OCH ₂ ) _n -CH ₂ OCH ₃ It can be used as a dopant, or a compound in which both R ¹ and R ² are -(CH ₂ OCH ₂ ) _n -CH ₂ OCH ₃ can be used as a dopant.

In another embodiment of the invention,

As shown in Experimental Example 1 below, as a result of measuring the contact angle with water or diiodomethane, R ¹ and R ² are -(CH compared to when at least one of R ¹ and R ² is an alkyl group or a halogen-substituted alkyl group. _{In the case of 2} OCH ₂ ) _n -CH ₂ OCH ₃ , it was experimentally confirmed that it was modified to be hydrophilic.

On the other hand, in one embodiment of the invention,

If the applied host property is hydrophobic, it is preferable that the dopant therefor is also hydrophobic, for example, at least one of the R ¹ and R ² moieties is a dopant compound of C ₁ -C ₂₀ alkyl substituted with halogen. It can be used as, or a compound in which both R ¹ and R ² are C ₁ -C ₂₀ alkyl substituted with halogen may be used as a dopant.

In another embodiment of the invention,

As shown in Experimental Example 1 below, as a result of measuring the contact angle with water or diiodomethane, the R ¹ and R ² are -(CH ₂ OCH ₂ ) _n -CH ₂ OCH ₃ , compared to the R ¹ and R ² It has been experimentally confirmed that when at least one is an alkyl group or a halogen-substituted alkyl group, it is modified to be hydrophobic. In addition, it was confirmed that, in particular, when at least one of R ¹ and R ² is a halogen-substituted alkyl group, it is more hydrophobic and surface energy is significantly reduced.

Therefore, as described above, the novel dopant compound provided in the present invention can be modified to suit each host property, and thus has excellent compatibility with the host, resulting from precipitation of the dopant compound, etc. It is possible to significantly improve problems such as a change or a decrease in efficiency as a product such as a display, a sensor, or the like that may appear therefrom.

In another aspect of the invention,

It can be seen from the following description that the compound represented by Chemical Formula 1 provided by the present invention is a dopant compound having improved compatibility with a host liquid crystal.

Chiral liquid crystal (LC) materials are useful in many applications, such as LC displays (LCDs) or polymer films with twisted structures. Typically, they consist of an LC host material containing one or more chiral dopants that induce the desired helical torsion. The effect of a chiral compound inducing a spirally twisted molecular structure in a liquid crystal host material is explained by its so-called helical twisting power (HTP). HTP is represented by Equation 1 below as a first approach sufficient for most practical uses:

[Equation 1]

HTP = 1/p·c

Where c is the concentration of the chiral dopant compound in the host material and p is the helical pitch.

As can be seen from Equation 1, a short pitch can be achieved using a large amount of chiral compound, or a chiral compound having a high absolute HTP. Therefore, when using a chiral compound having a low HTP, a large amount is required to induce a short pitch.

When a large amount of a chiral compound is required, it often adversely affects the properties of the LC host mixture, e.g., transparent point, anisotropy, viscosity, driving voltage or switching time, and the chiral compound can only be used as a pure enantiomer. Therefore, it is disadvantageous because it is uneconomical and difficult to synthesize.

Another disadvantage of the prior art chiral compounds is that they often exhibit low solubility in the LC host material, causing undesirable crystallization at low temperatures. To address this drawback, typically two or more different chiral dopants must be added to the host mixture. This has the disadvantage that it requires a higher cost and also requires additional effort to compensate for the temperature of the material, since different dopants must be selected such that their torsional temperature coefficients are usually compensated for each other.

As a result, high HTP, which can be used in small amounts, exhibits low temperature dependence of torsional forces, e.g., good solubility in LC host materials, and does not adversely affect the properties of the LC host, for example to use a constant reflection wavelength. There is a need for chiral compounds to have.

From this point of view, the dopant compound represented by the formula (1) provided by the present invention has excellent compatibility with the host, and thus a small amount can be used, and an adaptive amount can exhibit a sufficient pitch and desired characteristics. .

In addition, the dopant compound represented by Formula 1 of the present invention is useful as it may be a selectively modified compound to be applied to various hosts.

In another aspect of the invention,

The compound represented by Chemical Formula 1 may have several advantages as follows.

The starting material, S,S-binaphthol or R,R-binaphthol, or a derivative derived therefrom, can be commercially obtained and can be produced by being applied to processes such as mass production.

Compounds of different handedness (left handed and right handed) are prepared enantiomerically pure, so that both left and right helices can be formed in the nematic host. .

The compound represented by Chemical Formula 1 represents high HTP,

The compound represented by Formula 1 shows excellent solubility in the LC mixture.

When the compounds represented by Formula 1 are used as chiral dopants in the LC host material, they do not adversely affect the LC phase of the host.

In another aspect of the invention,

An LC composition comprising at least one compound represented by Formula 1 is provided.

In one embodiment of the invention,

A chimeric dopant compound represented by Chemical Formula 1, or a nematic or cholesteric liquid crystal composition comprising a stereoisomer thereof is provided.

In another aspect of the invention,

A chiral anisotropic polymer obtained by polymerizing the compound represented by the above formula (1) or the LC composition as described above and below, preferably in the form of a thin film in its oriented state, is provided.

In one embodiment of the invention,

A chiral anisotropic polymer obtained by polymerizing a nematic, or cholesteric liquid crystal composition comprising the compound represented by Formula 1 or a stereoisomer thereof, preferably in the form of a thin film in its orientation state is provided.

Furthermore, in another aspect of the invention,

An optical sensor comprising the nematic or cholesteric liquid crystal composition or the chiral anisotropic polymer is provided.

The present invention also provides an electro-optical display, LCD, optical film, polarizer, compensator, beam separator, reflective film, array layer, color filter, holographic element, hot stamping foil, color image, decorative or security label, LC Pigments, adhesives, cosmetics, diagnostic devices, nonlinear optical materials, optical information storage devices, electronic devices, organic semiconductors, field effect transistors (FETs), integrated circuit (IC) components, thin film transistors (TFTs), and radio recognition devices (Radio Frequency) Identification, RFID) tag, organic light emitting diode (OLED), electroluminescent display, lighting device, photoelectric device, sensor device, electrode material, photoconductor, electrophotographic recorder, laser material or device, or as a chiral dopant And compounds, compositions and polymers as described below.

In another aspect of the invention,

Polymerizable mesogens or LC compounds suitable for use as monomers or comonomers in a polymerizable LC mixture include, for example, WO 93/22397, EP 0 261 712, DE 195 04 224, WO 95/22586 , WO 97/00600, US 5,518,652, US 5,750,051, US 5,770,107 and US 6,514,578.

In one aspect of the invention,

The compound represented by the formula (1) is a polymerizable LC mixture, an anisotropic polymer gel, and an anisotropic polymer film, particularly having a uniform planar orientation, that is, a spirally twisted molecular structure in which the helical axis is oriented perpendicular to the plane of the film. Polymer films, for example, oriented cholesteric films.

Anisotropic polymer gels and displays comprising them are disclosed, for example, in DE 195 04 224 and GB 2 279 659.

Oriented cholesteric polymer films can be used, for example, as broadband reflective polarizers, color filters, security labels, or in the production of LC pigments.

Accordingly, another aspect of the present invention is a polymerizable LC composition comprising at least one compound of Formula 1, and at least one other compound that is a polymerizable and LC compound.

Here, the polymerizable LC composition is preferably a mixture of two or more compounds, one or more of which are polymerizable or crosslinkable compounds. The polymerizable compound having one polymerizer is also referred to hereinafter as "monoreactive". Crosslinkable compounds, ie compounds having two or more polymerisation groups, are hereinafter also referred to as “bi- or polyreactive”.

The polymerizable mesogen or LC compound is preferably a monomer, and more preferably a calamitic monomer. These materials typically have good optical properties, such as reduced chromaticity, and can be easily and quickly aligned to the desired orientation, which is particularly important for large scale industrial production of polymer films. It is also possible that the polymerizable material comprises one or more discotic monomers.

Furthermore, in one aspect of the invention,

As shown in Scheme 1 below,

Preparing a compound represented by Chemical Formula 2 from a compound represented by Chemical Formula 3 (step 1); And

A method for preparing a compound represented by Formula 1 of claim 1 is provided, comprising: preparing a compound represented by Formula 1 from a compound represented by Formula 2 (step 2):

[Scheme 1]

(In Scheme 1 above,

X ¹ , X ² , Y ¹ , Y ² , L ¹ , L ² , R ¹ , and R ² are as defined in Formula 1).

In one embodiment of the present invention, the manufacturing method represented by Reaction Scheme 1 may be performed as in the Examples of the present invention below, or may be a manufacturing method easily performed by a person skilled in the art to change/modify the present invention. Includes this.

In another embodiment of the present invention, at least the substituent portion corresponding to the L and R parts can be appropriately modified or modified for the purpose of improving the compatibility with the host desired by the present invention, reaction time, solvent , Reaction control that can be changed or modified normally, such as conditions, can be applied, and the manufacturing method derived therefrom is also included in the present invention.

Furthermore, in one aspect of the invention,

The compounds of formula 1 of the present invention are used in LC mixtures for LCDs exhibiting a twisted structure such as, for example, twisted or supertwisted nematic (TN, STN) displays with multiple or active matrix addressing, or , Or a multi-region LCD as described in WO 98/57223, a multicolor cholesteric display as described in US 5,668,614 or a chiral LC operating on isotropic or blue as described in WO 02/93244 Surface stabilized or polymer stabilized cholesteric structure display as described in WO 92/19695, WO 93/23496, US 5,453,863 or US 5,493,430 for LCDs with variable pitch, such as displays comprising a medium It can be used for cholesteric displays such as surface stabilized or polymer stabilized cholesteric texture display (SSCT, PSCT).

In addition, in one aspect of the present invention,

The compounds of formula 1 of the present invention are also suitable for use in thermochromic or photochromic LC media, each of which changes its color upon temperature change or light irradiation.

Accordingly, another aspect of the present invention is a cholesteric LCD comprising a cholesteric LC medium containing one or more chiral compounds of Formula 1, or stereoisomers thereof.

The compound of formula (1) has good solubility in the LC host mixture and can be added as a dopant to the LC host in small amounts, with little effect on the mode of the phase and the total lightness of the mixture, and can optionally be added in large quantities.

The chiral dopant compound of Chemical Formula 1 of the present invention has excellent compatibility with a host, and thus, undesirable spontaneous crystallization is reduced at a low temperature, and the process temperature range of the mixture can be widened.

In addition, they can be used for the production of highly torsional LC media, even if they have low HTP, since they can increase the dopant concentration to provide a low pitch value (i.e., high torsion) without affecting the mixture properties. . Therefore, the use of a second dopant, which is often added to prevent crystallization, may be excluded.

In one aspect of the invention,

Since the chiral compounds of Formula 1 exhibit high HTP values, highly helical twisting, ie, low pitch, LC mixtures can be prepared by adding these compounds in very small amounts.

The LC mixture preferably comprises 0.1 to 30% by weight, in particular 1 to 25% by weight, very particularly preferably 2 to 15% by weight of the chiral compound of formula (1). Preferably, the mixture comprises 1 to 3 chiral compounds of formula (I).

In one embodiment of the invention,

The LC mixture consists of 2 to 25, preferably 3 to 15 compounds, at least one of which is a chiral compound of formula (I). Other compounds are preferably low molecular weight LC compounds selected from:

Nematic or nematogenic materials such as phenyl or cyclohexyl esters of cyclohexane carboxylic acids, cyclohexyl esters, cyclohexyl benzoates, benzylidene-aniline, biphenyl, terphenyl, phenyl or cyclohexylcarboxylic acid, cyclohexyl Phenyl or cyclohexyl ester of benzoic acid, phenyl or cyclohexyl ester of cyclohexylcyclohexanecarboxylic acid, cyclohexylphenyl ester of benzoic acid, cyclohexylphenyl ester of cyclohexanecarboxylic acid, and cyclohexylphenyl ester of cyclohexylcyclohexanecarboxylic acid, Phenylcyclohexane, cyclohexylbiphenyl, phenylcyclohexylcyclohexane, cyclohexylcyclohexane, cyclohexylcyclohexene, cyclohexylcyclohexylcyclohexene, 1,4-bis-cyclohexylbenzene, 4,4'- Bis-cyclohexylbiphenyl, phenyl- or cyclohexylpyrimidine, phenyl- or cyclohexylpyridine, phenyl- or cyclohexylpyridazine, phenyl- or cyclohexyldioxane, phenyl- or cyclohexyl-1,3-di Thiane, 1,2-diphenyl-ethane, 1,2-dicyclohexylethane, 1-phenyl-2-cyclohexylethane, 1-cyclohexyl-2-(4-phenylcyclohexyl)-ethane, 1-cyclo Hexyl-2-biphenyl-ethane, 1-phenyl-2-cyclohexyl-phenylethane, halogenated or unhalogenated stilbene, benzyl phenyl ether, tolane, substituted cinnamic acid and other classes of nematic or nematogenic matter. The 1,4-phenylene group in these compounds can also be flankingly mono- or difluorinated. The LC mixture is preferably based on non-chiral compounds of this type.

In one aspect of the invention,

In the present invention, in particular, in order to improve the compatibility with the host, the compound represented by Formula 1 is modified to prepare a derivative. Particularly, it could be modified with hydrophobicity or hydrophilicity, whereby the desired pitch could be achieved even when added in a small amount to the host liquid crystal. Also, when the compatibility between the conventional host and the dopant is poor, problems such as precipitation appear, Or there is an advantage that can improve the problems such as the efficiency of the product appearing therefrom.

Hereinafter, preferred embodiments and experimental examples of the present invention will be described in detail. The terms or words used in the present specification and claims are not interpreted as being limited to ordinary or dictionary meanings, and should be interpreted as meanings and concepts consistent with the technical matters of the present invention.

The examples and test examples described in the present specification are preferred embodiments of the present invention, and do not represent all of the technical spirit of the present invention, and thus there may be various equivalents and modification examples that can replace them at the time of this application. .

<Production Example 1> Preparation of 2,2'-bis(4-hydroxyphenylazo)-1,1'-binaphthalene

1,1'-Binaphthyl-2,2'-diamine (500 mg, 1.76 mmol) was added to the flask, dissolved in water (8.5 mL) and concentrated hydrochloric acid (1.25 mL). To this, a solution of sodium nitrite (250 mg, 4.22 mmol) dissolved in water (10 mL) in an ice bath was slowly added dropwise. This was reacted at 0° C. for 15 minutes, and the solution was slowly added dropwise to a mixed solution of an aqueous solution of sodium hydroxide (450 mg, 22.53 mmol) in phenol (360 mg, 3.87 mmol) and water (15 mL) in another flask. do. After reaction at room temperature for 15 minutes, 1M hydrochloric acid aqueous solution was added to acidify. The precipitated solid is filtered while washing with water. After the filtered solid is dried, it is separated by column chromatography with a mixed solution of hexane:ethyl acetate (2:1). The isolated compound was a red solid compound, and 0.54 g (62%) was obtained.

¹ H NMR (300 MHz, DMSO-d ₆ ) δ 10.15 (s, 2H), 8.32-7.92 (m, 6H), 7.57 (t, J = 7.4 Hz, 2H), 7.42-7.31 (m, 2H), 7.21 (m, 6H), 6.68 (d, J = 8.8 Hz, 4H).

<Production Example 2> Preparation of 2-[4-decanoyloxyphenylazo]-2'-(4-hydroxyphenylazo)-1,1'-binaphthalene

The compound of Preparation Example 1 (200 mg, 0.4 mmol) was added to a flask, and dichloromethane (10 mL) was added thereto to dissolve. Then, DMAP (5 mg, 0.04 mmol) and triethylamine (0.6 ml, 4 mmol) were added. After that, decanoyl chloride (0.074 mL, 0.36 mmol) was added dropwise at 0° C., followed by reaction at room temperature for 15 minutes. After completion of the reaction, extraction was performed with dichloromethane. The organic layer is dried over magnesium sulfate, and then the solvent is removed. The concentrated solution is then separated by column chromatography. The isolated compound was obtained as a red solid compound, 0.09 g (35%).

¹ H NMR (400 MHz, Acetone-d ₆ ) δ 8.24-7.99 (m, 6H), 7.63-7.50 (m, 2H), 7.47-7.21 (m, 8H), 7.04 (d, J = 8.8 Hz, 2H ), 6.73 (d, J = 8.9 Hz, 2H), 2.52 (t, J = 7.4 Hz, 2H), 1.66 (q, J = 7.5 Hz, 2H), 1.41-1.18 (m, 12H), 0.86 (t , J = 6.8 Hz, 3H).

<Production Example 3> 2-[4-hydroxyphenylazo]-2'-[4-(2-(2-(2-methoxyethoxy)ethoxy)acetoxy)-phenylazo]-1,1 '-Production of binaphthalene

2-[2-(2-methoxyethoxy)ethoxy]acetic acid (0.12 mL, 0.8 mmol) was added to a round neck flask, dissolved in dichloromethane (10 mL), and triethylamine (0.2 ml, 1.4 mmol). After that, methanesulfonyl chloride (0.1 mL, 1.4 mmol) was added dropwise at 0° C., followed by reaction at room temperature for 5 hours. In another flask, the compound of Preparation Example 1 (200 mg, 0.4 mmol), DMAP (5 mg, 0.04 mmol) was added, and dissolved in dichloromethane (10 mL). The compound reacted in the first flask is cannulated into the second flask. After reacting at room temperature for 3 hours, extraction is performed with dichloromethane. The organic layer is dried over magnesium sulfate, and then the solvent is removed. The concentrated solution is then separated by column chromatography with a mixed solution of hexane:ethyl acetate (1:1). The isolated compound was 0.073 g (28%) as a red solid compound.

¹ H NMR (400 MHz, Acetone-d ₆ ) δ 8.26-8.04 (m, 6H), 7.69-7.49 (m, 2H), 7.48-7.32 (m, 6H), 7.27 (d, J = 8.9 Hz, 2H ), 7.12 (d, J = 8.9 Hz, 2H), 6.73 (d, J = 8.9 Hz, 2H), 4.38 (s, 2H), 3.78-3.68 (m, 2H), 3.65-3.59 (m, 2H) , 3.59-3.53 (m, 2H), 3.50-3.41 (m, 2H), 3.26 (s, 3H).

Using the compounds prepared in Preparation Examples 1-3, the following Examples and Comparative Example compounds were prepared.

<Example 1> 2,2'-bis[4-(4,4,5,5,6,6,7,7,8,8,9,9,9-tridecafluorononanoyloxy) Preparation of phenylazo]-1,1'-binaphthalene

2H,2H,3H,3H-perfluorononanoic acid (550 mg, 1.4 mmol) was added to the flask, dichloromethane (20 mL) was added thereto, and triethylamine (0.5 ml, 3.5 mmol) was added. Then, methanesulfonyl chloride (0.2 mL, 2.8 mmol) was added dropwise at 0° C., and then reacted at room temperature for 17 hours. In another flask, the compound of Preparation Example 1 (100 mg, 0.2 mmol) and DMAP (12 mg, 0.1 mmol) were added and dissolved in dichloromethane (10 mL). The compound reacted in the first flask is cannulated into the second flask. After reacting at room temperature for 2 days, extraction was performed with dichloromethane. The organic layer is dried over magnesium sulfate, and then the solvent is removed. The concentrated solution is then separated by column chromatography with a mixed solution of hexane:ethyl acetate (1:1). The isolated compound was obtained as a red solid compound, 0.06 g (38%).

¹ H NMR (400 MHz, Acetone-d ₆ ) δ 8.29-8.02 (m, 6H), 7.60 (t, J = 7.4 Hz, 2H), 7.50-7.29 (m, 8H), 7.09 (d, J = 8.8 Hz, 4H), 2.97 (t, J = 7.5 Hz, 4H), 2.78-2.57 (m, 4H).

<Example 2> 2-[4-decanoyloxyphenylazo]-2'-[4-(4,4,5,5,6,6,7,7,8,8,9,9,9- Preparation of tridecafluorononanoyloxy)phenylazo]-1,1'-binaphthalene

2H,2H,3H,3H-perfluorononanoic acid (180 mg, 0.45 mmol) was added to the flask, dichloromethane (10 mL) was dissolved, triethylamine (0.11 ml, 0.75 mmol) was added. Thereafter, methanesulfonyl chloride (0.06 mL, 0.75 mmol) was added dropwise at 0° C., and then reacted at room temperature for 5 hours. In another flask, the compound of Preparation Example 2 (100 mg, 0.15 mmol) and DMAP (2 mg, 0.015 mmol) were added and dissolved in dichloromethane (10 mL). The compound reacted in the first flask is cannulated into the second flask. After reacting at room temperature for 3 hours, extraction is performed with dichloromethane. The organic layer is dried over magnesium sulfate, and then the solvent is removed. The concentrate is separated by column chromatography. The isolated compound was obtained as a red solid compound, 0.07 g (47%).

¹ H NMR (400 MHz, Acetone-d ₆ ) δ 8.25-8.09 (m, 6H), 7.60 (t, J = 7.4 Hz, 2H), 7.48-7.33 (m, 8H), 7.12-7.08 (m, 2H ), 7.08-7.03 (m, 2H), 2.97 (t, J = 7.5 Hz, 2H), 2.77-2.61 (m, 2H), 2.53 (t, J = 7.4 Hz, 2H), 1.67 (q, J = 7.5 Hz, 2H), 1.40-1.26 (m, 12H), 0.87 (t, J = 6.8 Hz, 3H).

<Example 3> Preparation of 2,2'-bis[4-(2-(2-(2-methoxyethoxy)ethoxy)acetoxy)-phenylazo]-1,1'-binaphthalene

2-[2-(2-methoxyethoxy)ethoxy]acetic acid (0.16 mL, 1 mmol) was added to a round neck flask, dissolved in dichloromethane (20 mL), triethylamine (0.36 ml, 2.5 mmol). After that, methylsulfonyl chloride (0.12 mL, 1.5 mmol) was added dropwise at 0° C., and reacted at room temperature for 17 hours. In another flask, the compound of Preparation Example 1 (200 mg, 0.4 mmol) and DMAP (17 mg, 0.14 mmol) were added and dissolved in dichloromethane (10 mL). The compound reacted in the first flask is cannulated into the second flask. After reacting it at room temperature for 17 hours, it was extracted with dichloromethane. The organic layer is dried over magnesium sulfate, and then the solvent is removed. The concentrate is separated by column chromatography. The isolated compound was 0.14 g (29%) as a red solid compound.

¹ H NMR (400 MHz, Acetone-d ₆ ) δ 8.26-8.07 (m, 6H), 7.60 (t, J = 7.4 Hz, 2H), 7.47-7.30 (m, 8H), 7.12 (d, J = 8.8 Hz, 4H), 4.38 (s, 4H), 3.77-3.68 (m, 4H), 3.67-3.51 (m, 8H), 3.50-3.41 (m, 4H), 3.26 (s, 6H).

<Example 4> 2-[4-decanoyloxyphenylazo]-2'-[4-(2-(2-(2-methoxyethoxy)ethoxy)acetoxy)-phenylazo]-1, Preparation of 1'-binaphthalene

2-[2-(2-methoxyethoxy)ethoxy]acetic acid (0.05 mL, 0.3 mmol) was added to a 1-neck round-bottom flask, dissolved with dichloromethane (20 mL), and triethylamine (1.8 ml, 0.6) mmol). After that, methanesulfonyl chloride (0.05 mL, 0.6 mmol) was added dropwise at 0° C., and then reacted at room temperature for 5 hours. In another flask, the compound of Preparation Example 2 (80 mg, 0.12 mmol) and DMAP (2 mg, 0.012 mmol) were added and dissolved in dichloromethane (10 mL). The compound reacted in the first flask is cannulated into the second flask. After reacting at room temperature for 3 hours, extraction is performed with dichloromethane. The organic layer was dried over MgSO _4, and then the solvent was removed. The concentrated solution is then separated by column chromatography with a mixed solution of hexane:ethyl acetate (1:1). The isolated compound was obtained as a red solid compound, 0.05 g (52%).

¹ H NMR (400 MHz, Acetone-d ₆ ) δ 8.27-8.09 (m, 6H), 7.61 (t, J = 7.4 Hz, 2H), 7.49-7.32 (m, 8H), 7.12 (d, J = 8.8 Hz, 2H), 7.06 (d, J = 8.8 Hz, 2H), 4.39 (s, 2H), 3.76-3.68 (m, 2H), 3.64-3.59 (m, 2H), 3.59-3.53 (m, 2H) , 3.50-3.42 (m, 2H), 3.26 (s, 3H), 2.53 (t, J = 7.4 Hz, 2H), 1.67 (q, J = 7.3 Hz, 2H), 1.42-1.24 (m, 12H), 0.87 (t, J = 6.8 Hz, 3H).

<Example 5> 2-[4-(4,4,5,5,6,6,7,7,8,8,9,9,9-tridecafluorononanoyloxy)phenylazo]- Preparation of 2'-[4-(2-(2-(2-methoxyethoxy)ethoxy)acetoxy)-phenylazo]-1,1'-binaphthalene

2H,2H,3H,3H-perfluorononanoic acid (130 mg, 0.45 mmol) was added to a round neck flask, dissolved in dichloromethane (10 mL), and triethylamine (0.08 ml, 0.55 mmol) dissolved. Put it in. Thereafter, methanesulfonyl chloride (0.04 mL, 0.55 mmol) was added dropwise at 0° C., and then reacted at room temperature for 5 hours. In another flask, the compound of Preparation Example 3 (73 mg, 0.11 mmol) and DMAP (2 mg, 0.011 mmol) were added and dissolved in dichloromethane (10 mL). The compound reacted in the first flask is cannulated into the second flask. After reacting at room temperature for 3 hours, extraction is performed with dichloromethane. The organic layer was dried over MgSO _4, and then the solvent was removed. The concentrated solution is then separated by column chromatography with a mixed solution of hexane:ethyl acetate (1:1). The isolated compound was obtained as 0.045 g (41%) as a red solid compound. ¹ H NMR (400 MHz, Acetone-d6) δ 8.27-8.07 (m, 6H), 7.67-7.55 (m, 2H), 7.50-7.34 (m, 8H), 7.19-7.04 (m, 4H), 4.38 ( s, 2H), 3.79-3.68 (m, 2H), 3.67-3.59 (m, 2H), 3.59-3.51 (m, 2H), 3.49-3.38 (m, 2H), 3.26 (s, 3H), 2.97 ( t, J = 7.5 Hz, 2H), 2.80-2.57 (m, 2H).

<Comparative Example> Preparation of 2,2'-bis(4-decanoyloxyphenylazo)-1,1'-binaphthalene

The Preparation Example 1 compound (150 mg, 0.3mmol) was put in a round neck flask with 1 neck, and dichloromethane (20 mL) was added to dissolve it. Then, DMAP (4 mg, 0.03 mmol) and triethylamine (0.43 ml, 3 mmol) were added. After that, dicanoyl chloride (0.25 mL, 1.35 mmol) was added dropwise at 0° C., and reacted at room temperature for 3 hours. After completion of the reaction, extraction was performed with dichloromethane. The organic layer was dried over MgSO _4, and then the solvent was removed. The concentrated solution is then separated by column chromatography with a mixed solution of hexane:ethyl acetate (2:1). The isolated compound was 0.17 g (71%) as a red solid compound.

¹ H NMR (400 MHz, Acetone-d ₆ ) δ 8.17 (m, 6H), 7.60 (t, J = 7.4 Hz, 2H), 7.48-7.33 (m, 8H), 7.05 (d, J = 8.8 Hz, 4H), 2.53 (t, J = 7.4 Hz, 4H), 1.66 (q, J = 7.5 Hz, 4H), 1.45-1.20 (m, 24H), 0.87 (t, J = 6.7 Hz, 6H).

Table 1 below shows the chemical structural formulas of the compounds of Examples 1-5 of the present invention.

Example Chemical structural formula One

2

3

4

5

<Experimental Example 1> Surface energy measurement

In order to evaluate whether the chiral dopant compound of the present invention can be applied to various hosts, that is, to evaluate compatibility with a host, a surface energy measurement experiment was performed as follows.

Specifically, after coating the compounds of the Examples and Comparative Examples thinly on a glass substrate, contact angles were measured by dropping a drop of water and diiodomethane, respectively, and calculation of surface energy from the measured contact angles was measured using two solutions. It was calculated by a geometric mean method well known as a method, and the results are shown in Table 2 and FIG. 1 below.

compound Contact angle Surface energy
(dyne/cm) water Diaodomethane Comparative example 99.3 33.2 41.4 Example 1 107.2 49.1 24.7 Example 3 83.2 42.2 39.1

Looking at Table 2, it can be confirmed that the surface energy of Examples 1 and 3 of the present invention was adjusted compared to the comparative example, and further, it was confirmed that the contact angle with water or diiodomethane was changed, respectively.

Therefore, the chiral dopant having a controlled surface energy as in the present invention has excellent compatibility with a host, and has an advantage that can be applied to various hosts.

For example, host liquid crystals used in LCD modes such as TN, IPS, and VA need to adjust viscosity, dielectric anisotropy, and surface energy according to the driving method and initial alignment state. These host liquid crystals are used as cholesteric liquid crystal phases. When changing, it is possible to apply a chiral dopant whose surface energy is controlled as in the present invention.

In addition, by simply adding a chiral dopant to the host liquid crystal used in the LCD mode, a cholesteric liquid crystal phase can be realized, from which a composition applicable to sensors, smart windows, and the like can be formed.

Claims (10)

A chiral dopant compound represented by Formula 1 below or a stereoisomer thereof:
[Formula 1]

(In the above formula 1,
X ¹ and X ² are each independently N or CH,
Y ¹ and Y ² are each independently N or CH,
L ¹ and L ² are each independently

,

,

,

,

,

, or

Is, and
R ¹ and R ² are each independently substituted or unsubstituted C ₁ -C ₂₀ alkyl with halogen, or -(CH ₂ OCH ₂ ) _n -CH ₂ OCH ₃ (where n is an integer from 0 to 20) )
When one of R ¹ and R ² is unsubstituted alkyl, the other is not unsubstituted alkyl).
According to claim 1,
A chiral dopant compound or a stereoisomer thereof, characterized in that X ¹ , X ² , Y ¹ , and Y ² are N.
According to claim 1,
L ¹ and L ² are

Chiral dopant compound, or a stereoisomer thereof, characterized in that is.
According to claim 1,
The chiral dopant compound represented by Formula 1 is a compound, or a stereoisomer thereof, characterized in that it is any one selected from the group consisting of:

,

,

,

, And

.
According to claim 1,
The chiral dopant compound has a surface energy of 20-50 dyne/cm, a chiral dopant compound, or a stereoisomer thereof.
As shown in Scheme 1 below,
Preparing a compound represented by Chemical Formula 2 from a compound represented by Chemical Formula 3 (step 1); And
A method for preparing a compound represented by Formula 1 of claim 1 comprising: preparing a compound represented by Formula 1 from a compound represented by Formula 2 (Step 2):
[Scheme 1]

(In Scheme 1 above,
X ¹ , X ² , Y ¹ , Y ² , L ¹ , L ² , R ¹ , and R ² are as defined in claim 1).
A nematic or cholesteric liquid crystal composition comprising the chiral dopant compound of claim 1 or a stereoisomer thereof.
A chiral anisotropic polymer obtained by polymerizing the chiral dopant compound of claim 1, or a stereoisomer thereof, or the nematic or cholesteric liquid crystal composition of claim 7, in the form of a thin film in its orientation.
An optical sensor comprising the nematic or cholesteric liquid crystal composition of claim 7.
An optical sensor comprising the chiral anisotropic polymer of claim 8.

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