JP2019189562A - Diacetylene derivative - Google Patents

Abstract

To provide a novel diacetylene derivative in which the birefringence and the dielectric anisotropy are comparatively large and which is chemically stable.SOLUTION: A diacetylene derivative of this invention is chemically and thermally stable because it includes a diacetylene skeleton in the central part of the molecular structure. Further, structures of both terminal groups of the diacetylene derivative are different from each other in such a way that in the structure a sulfur atom is included only in one terminal group and no sulfur atom is included in the other terminal group. As a result, the diacetylene derivative has high birefringence originating from the sulfur atom, and moreover, can exhibit mesomorphism in the vicinity of room temperature corresponding to the structure.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a novel diacetylene derivative.

  In recent years, there has been a demand for higher functionality of liquid crystal display elements. The performance of a liquid crystal display element greatly depends on the physical properties of a liquid crystal substance which is a constituent material and a liquid crystal composition including the liquid crystal substance. In general, a liquid crystal substance has dielectric anisotropy in which a dielectric constant in a major axis direction of liquid crystal molecules and a dielectric constant in a direction perpendicular to the liquid crystal molecule are different. Moreover, it has refractive index anisotropy (birefringence) in which the refractive index when parallel to the major axis direction of the liquid crystal molecules and the refractive index when perpendicular are different.

  In a liquid crystal display element, for example, a nematic liquid crystal is sealed between two glass substrates, and a twisted nematic liquid crystal cell manufactured so that the alignment direction of liquid crystal molecules is twisted by 90 ° between the two glass substrates ( A TN liquid crystal cell) is well known. In this TN liquid crystal cell, the orientation of liquid crystal molecules is manipulated by applying a voltage to change the transmitted light intensity. However, when the dielectric anisotropy of the liquid crystal molecules increases, the threshold voltage at which the transmitted light intensity begins to change may be reduced. In addition, the driving voltage of the liquid crystal display element can be lowered.

  Further, if the birefringence of the liquid crystal molecules increases, the phase difference when light passes through increases. If this retardation film is doped with liquid crystal molecules having a large birefringence, a thin retardation film having high retardation can be formed. For this reason, there is a need for a liquid crystal material or liquid crystal composition having higher birefringence and dielectric anisotropy.

  In a liquid crystal cell, several types of liquid crystal substances and non-liquid crystal compounds are used in order to obtain desired characteristics such as temperature range and dielectric anisotropy in a liquid crystal state, rather than using a single liquid crystal substance. Mixed liquid crystal compositions are often used. If a substance having a large birefringence is blended, the birefringence and dielectric anisotropy of the entire liquid crystal composition can be improved. Therefore, not only a liquid crystal substance but also a non-liquid crystalline substance can be applied to a substance having a large birefringence. Development is underway.

  Here, as a substance having a large birefringence, for example, a diacetylene compound in which a phenylene group or a naphthylene group having an alkyl group or an alkoxy group bonded to both ends of a diacetylene skeleton has been proposed. It is described that it is used as a liquid crystal member for improving the response performance of a liquid crystal display element (see Patent Documents 1, 2, 3, 4 and Non-Patent Document 1). However, the value of the birefringence is unknown, and the stability against heat and light is also unknown.

  In recent years, it has been known that a substance having a molecular structure containing a sulfur atom can improve birefringence, dielectric constant, and dielectric anisotropy. As such a substance, a diacetylene compound containing a sulfur atom is known. Has been proposed (see Patent Document 5).

JP-A-11-001445 Japanese Patent Laid-Open No. 06-211704 US Pat. No. 5,338,481 Special table 2004-518608 gazette JP 2012-167068 A

B. Grant, Mol. Cryst. Liq. Cryst., 1978, vol. 48, 175-182

  However, at present, there are not so many substances having sufficiently large birefringence and dielectric anisotropy and chemically stable. Conventionally, a plurality of substances have been mixed in order to improve the properties of the liquid crystal composition. However, the types of substances to be blended tend to increase, and adjustment is complicated. If a substance with sufficiently large birefringence and dielectric anisotropy can be used, a wide range of characteristic adjustments can be made with a small number of materials. However, since there are few options for such substances, complicated adjustment work cannot be avoided. In addition, there is a problem that there is a limit to the blending design of the liquid crystal composition that can be used practically.

  Moreover, when the miscibility (compatibility) of the substance to mix | blend is poor, a liquid crystal composition will become optically non-uniform | heterogenous and the optical characteristic of a liquid crystal cell will fall. Therefore, it is desirable that a substance having sufficiently large birefringence and dielectric anisotropy can be selected with a high degree of freedom from the viewpoint of compatibility. However, there is a problem that various substances are not provided enough to satisfy the requirement.

  Here, liquid crystal materials tend to have better miscibility with liquid crystal materials than non-liquid crystal materials. For this reason, a liquid crystal material having high birefringence and high dielectric anisotropy is strongly desired. On the other hand, in order to improve birefringence and dielectric anisotropy, the molecular structure must be anisotropic and the electronic state must be dense. (In particular, the phase transition temperature from the crystal phase to the liquid crystal phase and the melting point of the liquid crystal substance (hereinafter referred to as “Tm” as appropriate)) are increased. Therefore, it has been difficult to create a liquid crystal substance that improves characteristics such as birefringence and dielectric anisotropy and that is in a liquid crystal state near room temperature.

  Furthermore, although the molecular structure containing the sulfur atom described above can improve birefringence and dielectric anisotropy, it is difficult to develop liquid crystallinity, and the disulfide containing sulfur atom disclosed in Patent Document 5 is difficult. Although the acetylene compound has a large birefringence as compared with the conventional compound, it is not necessarily a single substance (liquid crystal substance) exhibiting liquid crystallinity.

  For this reason, there has been a problem that a liquid crystal substance exhibiting liquid crystallinity in a temperature region near room temperature and having a larger birefringence or dielectric anisotropy is not sufficiently provided.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a novel diacetylene derivative having relatively large birefringence and dielectric anisotropy and being chemically stable.

  In order to achieve this object, the diacetylene derivative according to claim 1 is a diacetylene derivative represented by the following general formula (1).

（式中、Ｒ^１は、置換基を備えていても良い炭素数１〜２０のアルキル基若しくはアルコキシ基または置換基を備えていても良い炭素数２〜２０のアルケニル基、Ｒ^２は置換基を備えていても良い炭素数１〜２０のアルキル基または置換基を備えていても良い炭素数２〜２０のアルケニル基、Ａ^１は、非置換またはハロゲン原子、シアノ基、メチル基、エチル基、ハロゲン化アルキル基、炭素数１〜２０のアルコキシ基により一置換若しくは多置換されていてもよい芳香族環基または複素環基である。）

(In the formula, R ¹ is an optionally substituted alkyl group having 1 to 20 carbon atoms, an alkoxy group, or an optionally substituted alkenyl group having 2 to 20 carbon atoms, and R ² is a substituent. An optionally substituted alkyl group having 1 to 20 carbon atoms or an optionally substituted alkenyl group having 2 to 20 carbon atoms, A ¹ is an unsubstituted or halogen atom, cyano group, methyl group, ethyl group , A halogenated alkyl group, an aromatic ring group or a heterocyclic group which may be mono- or polysubstituted by a C 1-20 alkoxy group.)

The diacetylene derivative according to claim 2 is the diacetylene derivative according to claim 1, wherein the A ¹ is unsubstituted or a halogen atom, a cyano group, a methyl group, an ethyl group, a halogenated alkyl group, or a C 1-20 carbon atom. An aromatic ring group which may be mono- or poly-substituted by an alkoxy group.

The diacetylene derivative according to claim 3 is the diacetylene derivative according to claim 2, wherein A ¹ is a 1,4-phenylene group and has liquid crystallinity.

The diacetylene derivative according to claim 4 is the diacetylene derivative according to claim 3, wherein R ¹ is an alkyl group having 1 to 16 carbon atoms which may have a substituent.

The diacetylene derivative according to claim 5 is the diacetylene derivative according to claim 3 or 4, wherein the carbon number of the alkyl group of R ¹ is an even number.

  Since the diacetylene derivative according to claim 1 has a relatively large birefringence and dielectric anisotropy, it can be suitably used for an optical device, an electro-optical device, and the like. For example, a liquid crystal display element (liquid crystal composition) It can be used as a material of the product. In addition, by using the present diacetylene derivative, there is an effect that the birefringence and dielectric anisotropy of the liquid crystal composition can be improved.

According to the diacetylene derivative of claim 2, since A ¹ is an aromatic ring group, there is an effect that it can be easily synthesized as compared with the case where a non-aromatic heterocyclic group is introduced into the structure.

  According to the diacetylene derivative according to claim 3, in addition to the effect of the diacetylene derivative according to claim 2, it has liquid crystallinity, so that the present diacetylene derivative itself can be used as a liquid crystal substance. There is. In addition, for example, when the diacetylene derivative is used in forming a liquid crystal composition, it is superior in miscibility compared with non-liquid crystalline ones, so that it is possible to suppress turbidity and to suppress deterioration of optical properties. There is an effect that can be.

According to the diacetylene derivative according to claim 4, in addition to the effect exerted by the diacetylene derivative according to claim 3, since R ¹ is an alkyl group having 1 to 16 carbon atoms which may have a substituent, nematic There is an effect that the liquid crystal phase can be more easily formed.

According to the diacetylene derivative according to claim 5, in the diacetylene derivative according to claim 3 or 4, since the carbon number of the alkyl group of R ¹ is an even number, the temperature range for forming the nematic liquid crystal phase is further increased. There is an effect that it can be widened.

It is a figure explaining the phase transition behavior of a diphenyl diacetylene derivative. 3 is a graph showing the temperature dependence of birefringence at a measurement wavelength of 550 nm for the diacetylene derivatives of Example 1 and Comparative Example 1. FIG.

  Hereinafter, the present invention will be described in detail.

  The present invention is a diacetylene derivative represented by the following general formula (1).

本発明のジアセチレン誘導体は、分子構造の中央部にジアセチレン（以下、適宜「１，３−ブタジイン」と称することがある。）骨格を備えている。ジアセチレン骨格部分は、本発明の一般式（１）の化合物の特徴である。これらの化合物は化学的及び熱的に安定である。また、一般的に、ジアセチレン骨格を有する化合物は高い異方性を発現する。

The diacetylene derivative of the present invention has a diacetylene (hereinafter sometimes referred to as “1,3-butadiyne”) skeleton at the center of the molecular structure. The diacetylene skeleton portion is a feature of the compound of the general formula (1) of the present invention. These compounds are chemically and thermally stable. In general, a compound having a diacetylene skeleton exhibits high anisotropy.

Additionally, the diacetylene derivative of the present invention comprises a cyclic group A ¹ at both ends of the diacetylene backbone. The molecular structure of A ¹ is preferably one that can take a resonance structure with the diacetylene skeleton, and examples thereof include an aromatic carbocyclic group and a heterocyclic group having a hetero atom. A ¹ may be a single ring or a condensed ring.

  The heterocyclic group is preferably a 5- or 6-membered heterocyclic group, or a group containing 2 or 3 condensed rings containing a heterocyclic group, and the number of atoms constituting the heterocyclic group is 1 or 2 One or more heteroatoms are preferred, especially heteroatoms selected from N, O, S and Se.

  Examples of the heterocyclic group include groups derived from furan, pyrrole, thiophene, oxazole, thiazole, thiadiazole, selenophene, imidazole, pyridine, pyrimidine, pyrazine and the like. Particularly preferred are furan-2,5-diyl, thiophene-2,5-diyl, pyrrole-2,5-diyl, pyridine-2,5-diyl, and pyrimidine-2,5-diyl.

These groups may be provided with substituents, such as F, Cl, Br, I, CN, CH ₃ , C ₂ H ₅ , OCH ₃ , OC ₂ H ₅ , CF ₃ , OCF. ₃ , OCHF ₂ , OC ₂ F ₅ or SCF ₃ can be exemplified.

  Examples of the aromatic ring group include groups derived from phenylene, biphenyl, naphthalene, anthracene, phenanthrene and the like. This aromatic ring group may have a substituent. Examples of the substituent include an alkyl group such as a halogen atom, a cyano group, a methyl group, and an ethyl group, a halogenated alkyl group, a methoxy group, and an ethoxy group. Although the C1-C20 alkoxy group of this is illustrated, it is not restricted to this. The number of substituents may be one or two or more.

In the diacetylene derivative of the present invention, it is particularly preferred that A ¹ is 1,4-phenylene. In such a case, the compound has a diphenyl diacetylene structure represented by the following general formula (2).

  In addition, 1,4-phenylene may have a substituent. Examples of 1,4-phenylene include 1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1, 4-phenylene, 2,3-difluoro-1,4-phenylene, 2-chloro-1,4-phenylene, 2-cyano-1,4-phenylene, 2-methyl-1,4-phenylene, 3-methyl- 1,4-phenylene and the like can be mentioned.

  In particular, when the acetylene derivative is liquid crystalline, the above cyclic group is preferably unsubstituted 1,4-phenylene, and the diacetylene derivative having the molecular structure represented by the general formula (2) is: According to the structure, it exhibits nematic liquid crystal properties and smectic liquid crystal properties.

Further, the diacetylene derivative of the present invention includes terminal groups R ¹ and R ² S bonded to each of the cyclic groups. That is, this acetylene derivative has an asymmetric molecular structure in which the terminal groups on both sides are composed of different atomic groups.

The terminal group R ¹ bonded to one cyclic group is preferably an alkyl group, an alkoxy group or an alkenyl group which may have a substituent.

Examples of the substituent provided by R ¹ include a halogen atom, a cyano group, an alkyl group, a halogenated alkyl group, an alkoxy group such as a methoxy group or an ethoxy group, an aldehyde group, a carbonyl group, a hydroxy group, a carboxy group, a nitro group, and an amino group. , Sulfo group, nitro group and the like are exemplified, but not limited thereto. Further, R ¹ may be mono-substituted or poly-substituted by these groups.

Specific examples of R ¹ include linear alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl groups, 2-methylpropyl, and 2-methylbutyl. And an alkyl group having a branched chain such as 3-methylbutyl, 3-methylpentyl, 2-methylhexyl, 2-methyldecyl group. Also, 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl, 6-fluorohexyl, 4,4-difluorobutyl, 6,6-difluorohexyl, 2-chloroethyl, 3-chloropropyl, 4-chlorobutyl, 6 -An alkyl group having a substituent such as chlorohexyl, perfluoroethyl, perfluorobutyl, 1-cyanoethyl, 1-cyanobutyl, 2-cyanobutyl, 1-trifluoromethylethyl, 1-trifluoromethylbutyl, methoxy, ethoxy, Examples include alkoxy groups such as propoxy, butoxy, pentyloxy, hexyloxy, octyloxy, decyloxy, dodecyloxy, trifluoromethoxy, 2-fluorobutoxy, 2-fluorohexyloxy groups and alkoxy groups having substituents.

Further, as R ¹ , for example, an alkenyl group having 2 to 20 carbon atoms such as ethenyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, etc., or those having the above-mentioned substituents The alkenyl group of is illustrated.

Here, the carbon number of R ¹ may be 1 or more, but is preferably 2 or more. Further, the carbon number of R ¹ may be 30 or less, and is desirably 20 or less, more preferably 16 or less, from the viewpoint of easy availability of synthetic raw materials. In particular, in order to make the acetylene derivative liquid crystalline, R ¹ is preferably an alkyl group or an alkoxy group, in which case the number of carbon atoms is preferably 2 or more. By changing the molecular chain length of R ¹ , the expression state of the smectic phase and the nematic phase can be controlled. When R ¹ is an alkenyl group, the number of carbon atoms is 2 or more. When an unsaturated bond is contained in R ¹ (that is, a terminal group), the average refractive index tends to increase, and as a result, birefringence can be improved.

The other terminal group R ² S has a sulfur atom in the molecular structure, and has a structure in which it is bonded to a cyclic group via the sulfur atom. By introducing this sulfur atom into the molecular structure, the birefringence, dielectric constant, and dielectric anisotropy of the diacetylene derivative of the present invention are improved.

This terminal group R ² S is an alkylthio group or alkenylthio group which may have a substituent. The substituent is the same as the substituent for R ¹ described above, and R ² may be monosubstituted or polysubstituted by these substituents.

Specific examples of R ² include the same alkyl groups and alkenyl groups as those described above for R ¹ .

The carbon number of R ² may be 1 or more and 30 or less, and is preferably 20 or less because of the availability of synthetic raw materials. When R ² is an alkyl group, the carbon number of R ² is more preferably 1 or more and 6 or less, and particularly preferably 1 or more and 2 or less.

In addition, as described above, the introduction of an unsaturated bond into the terminal group can improve birefringence, but it is preferable to introduce it into R ² rather than R ¹ because of ease of synthesis. In that case, that is, when R ² is an alkenyl group, the number of carbon atoms is 2 or more.

The carbon numbers of R ¹ and R ² may be different or the same, and are preferably selected so that the asymmetry in the molecular structure of the diacetylene derivative is increased.

  As described above, in the present diacetylene derivative, the structures of both terminal groups are different, and the terminal group containing a sulfur atom is provided only in one cyclic group, and the terminal group bonded to the other cyclic group is the same. Does not contain sulfur atoms. For example, an alkylthio group containing a sulfur atom has a high polarizability and is an atomic group effective for improving birefringence. On the other hand, rod-like molecules into which alkylthio groups are introduced are unlikely to become liquid crystalline. For example, when both terminal groups of the diphenyl diacetylene skeleton are alkylthio groups, liquid crystallinity is not exhibited. However, by making only one of the terminal groups an atomic group containing a sulfur atom, the present diacetylene derivative exhibits nematic liquid crystallinity and smectic liquid crystallinity according to its structure. As a result, the present diacetylene derivative has a high birefringence attributed to the sulfur atom and realizes a low melting point and exhibits liquid crystallinity near room temperature.

R ¹ and R ² may be linear or branched, but when the diacetylene derivative is liquid crystalline, it must be a linear unsubstituted alkyl group. Is preferred.

Furthermore, R ¹ and R ² may have a highly polarizable substituent or a reactive group that reacts and polymerizes by heat or light at the terminal.

FIG. 1 is a diagram illustrating a phase transition behavior of a diphenyl diacetylene derivative using a diphenyl diacetylene derivative which is an embodiment of the diacetylene derivative of the present invention. Specifically, FIG. 1 shows the phase transition behavior of the liquid crystal phase of a diphenyl diacetylene derivative in which the alkyl group (R ¹ ) has 2 to 12 carbon atoms.

FIG. 1A is a diagram showing the relationship between the temperature range for forming a nematic liquid crystal phase or a smectic liquid crystal phase and the number of carbon atoms of the terminal group R ¹ . The horizontal axis indicates the carbon number of R ¹ (the carbon number of the alkyl group (n)), and the vertical axis indicates the temperature (° C.). A white square (□) indicates a phase transition temperature from an isotropic phase to a liquid crystal phase (hereinafter referred to as “ _TN ” as appropriate), and a white circle (◯) indicates a liquid crystal. A phase transition temperature from a phase (including both a nematic liquid crystal phase and a smectic liquid crystal phase) to a crystal phase (hereinafter referred to as “ _TCr ” as appropriate) is shown.

  In FIG. 1A, the white square (□) is an isotropic phase region, and the white circle (白) is a crystal phase region. A region between a white square (□) and a white circle (◯) is a liquid crystal phase.

When each of the phase transition temperatures (T _N , T _Cr ) in FIG. 1 (a) is calculated by linear approximation using Microsoft Excel (registered trademark), the isotropic phase of the diphenyl diacetylene derivative is calculated. A nematic phase transition line is determined at y = −0.5885n + 79.945. Similarly, the phase transition line of the liquid crystal phase-crystal phase transition point is obtained as y = −2.9203n + 58.482. As a result, in the case of 16 carbon atoms (n = 16), T _N = 70.5 ° C. and T _Cr = 11.8 ° C. That is, in the range where the carbon number of R ¹ is up to 16, the present diphenyl diacetylene derivative forms a liquid crystal phase at room temperature, and the expected liquid crystal phase temperature range may be 58.7 ° C. It is shown.

FIG. 1B is a diagram showing the relationship between the temperature range for forming the nematic liquid crystal phase and the carbon number of the terminal group R ¹ , and the horizontal axis is the carbon number of R ¹ as in FIG. The vertical axis represents temperature (° C.). The white square (□) indicates _TN , and the white circle (◯) indicates T _Cr or the phase transition temperature from the nematic liquid crystal phase to the smectic liquid crystal phase (hereinafter referred to as “ _TSm ” as appropriate). .). In FIG. 1B, for reference, the phase transition temperature ( _TCr ) from the smectic liquid crystal phase to the crystal phase is indicated by a white triangle (Δ).

As shown in FIG. 1B, a region between a white square (□) and a white circle (◯) is a region that becomes a nematic liquid crystal phase. When the approximate straight line is calculated in the same manner as in FIG. 1A, the isotropic phase-nematic phase transition point line is y = −0.5885n + 79.945, and the nematic phase-crystal phase transition (nematic phase in the case of 12 carbon atoms− The smectic phase transition) line is determined as y = 0.1303n + 44.972. That is, in the range where the carbon number of R ¹ is up to 16, the present diphenyl diacetylene derivative has T _N = 70.5 ° C., T _Cr or T _Sm transition = 47.1 ° C., and the carbon number of R ¹ is up to 16. In this range, it has been shown that the present diphenyl diacetylene derivative can sufficiently form a nematic phase.

Further, the number of carbon atoms in R ¹ is preferably an even number than an odd number. This is because when the number of carbon atoms is even as shown in FIG. 1, the temperature range for forming the nematic phase can be widened as compared with the case where the number of carbon atoms is odd.

  Next, a method for synthesizing the diacetylene derivative of the present invention will be described. The diacetylene derivative of the present invention can be produced by appropriately combining per se known reactions.

  Specifically, for example, as described in Jacs, 2016, 138 (38), PP. 12348-12351, it can be produced using a Glaser-Hay Coupling reaction.

The diacetylene derivative of the present invention thus obtained can be mixed with a liquid crystal substance to improve birefringence. Furthermore, in the case where a diphenyl diacetylene skeleton is provided, it can exhibit liquid crystallinity alone. In the case of exhibiting liquid crystallinity, the liquid crystal phase behavior (phase transition temperature) and birefringence differ depending on the group introduced into the derivative and the overall structure, but the isotropic phase transition temperature (hereinafter referred to as the transition from the liquid crystal phase to the isotropic phase) appropriately referred to as _{"T i".)} from the measured birefringent [Delta] n (550 nm were measured 10 ° C. at a low liquid crystal temperature) is preferably 0.25 or more, it is particularly preferable to indicate 0.30 or more.

  The liquid crystal composition containing the diacetylene derivative of the present invention is preferably constituted by using a compound showing a nematic phase as the other constituent component. Examples of such substances include known liquid crystal substances such as azoxybenzenes and mixtures thereof.

  EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

In the following Examples and Comparative Examples, observation, analysis, and measurement were performed using the following equipment.
¹ H NMR: JNM-ECS 400 (manufactured by JEOL Ltd.)
¹³ C NMR: Avans III 400 (manufactured by BRUKER ANALYTIK)
FT-IR: FT / IR-4200 (manufactured by JASCO Corporation)
Polarizing microscope: BX50 (Olympus Corporation)
Hot stage: LK-600PM (Rinkham)
Thermal analyzer: DSC-60 (manufactured by Shimadzu Corporation)
Liquid crystal cell for evaluation: KSRP-03 / B311 PINSS05 (manufactured by EHC)
Spectrometer: USB4000 (manufactured by Ocean optics, Inc.)

Example 1 Synthesis of 1-Heptyl-4- [4- (4-hexylthiophenyl) -1,3-butadiynyl] benzene According to the following synthesis scheme, 1-Heptyl-4- [4- (4-hexylthiophenyl) -1 , 3-butadiynyl] benzene was synthesized. In order to simplify the explanation, the compound may be referred to as “6S-DPDA-7” as appropriate hereinafter.

（１）1-Bromo-4-hexylthiobenzene（化合物１）の合成
100 mLなす型フラスコに4‐ブロモベンゼンチオール3.00 g(15.9 mmol)、1‐ブロモヘキサン2.62 g(15.9 mmol)、炭酸カリウム6.55 g(47.4 mmol)、アセトニトリル50 mLを加えて90℃のオイルバスで24時間撹拌した。有機層に酢酸エチルを用いて3回分液抽出を行い、飽和食塩水を用いた洗浄を行った。得られた有機層に無水硫酸マグネシウムを加えて脱水し、ろ過により硫酸マグネシウムを取り除いた後、エバポレーターとダイヤフラム真空ポンプによって酢酸エチルを取り除き、4.29 g(収率99%) の目的化合物を得た。得られた化合物の^１Ｈ−ＮＭＲのスペクトルデータにより、得られた目的化合物は、化合物１であることが確認された。以下に、その^１Ｈ−ＮＭＲのスペクトルデータを示す。
＜スペクトルデータ＞
¹H NMR (400 MHz, CDCl₃) δ 7.38 (d, J = 8.4 Hz , 2H), 7.17 (d, J = 8.4 Hz, 2H), 2.88 (t, J =7.2 Hz, 2H), 1.62 (tt, J = 7.2 and 7.6 Hz, 2H), 1.41 (tt, J = 6.8 and 7.6 Hz, 2H), 1.34‐1.23 (m, 4H), 0.88 (t, J = 6.4 Hz, 3H) ppm.

(1) Synthesis of 1-Bromo-4-hexylthiobenzene (Compound 1)
Add 4-bromobenzenethiol 3.00 g (15.9 mmol), 1-bromohexane 2.62 g (15.9 mmol), potassium carbonate 6.55 g (47.4 mmol) and acetonitrile 50 mL to a 100 mL eggplant-shaped flask in an oil bath at 90 ° C. Stir for 24 hours. The organic layer was extracted three times with ethyl acetate, and washed with saturated brine. The obtained organic layer was dehydrated by adding anhydrous magnesium sulfate, and after removing magnesium sulfate by filtration, ethyl acetate was removed by an evaporator and a diaphragm vacuum pump to obtain 4.29 g (yield 99%) of the target compound. From the ¹ H-NMR spectrum data of the obtained compound, it was confirmed that the obtained target compound was Compound 1. The ¹ H-NMR spectral data is shown below.
<Spectral data>
¹ H NMR (400 MHz, CDCl ₃ ) δ 7.38 (d, J = 8.4 Hz, 2H), 7.17 (d, J = 8.4 Hz, 2H), 2.88 (t, J = 7.2 Hz, 2H), 1.62 (tt , J = 7.2 and 7.6 Hz, 2H), 1.41 (tt, J = 6.8 and 7.6 Hz, 2H), 1.34‐1.23 (m, 4H), 0.88 (t, J = 6.4 Hz, 3H) ppm.

(2) Synthesis of 1-Hexylthio-4- (2-trimethylsilylethynyl) benzene (Compound 2)
Compound 1 2.00 g (7.32 mmol), trimethylsinylacetylene 2.1 mL (15.6 mmol), TEA (tetraethylamine): THF (tetrahydrofuran) = 3: 1 (v / v) in a 100 mL two-necked flask 30 mL was added, and dissolved oxygen was degassed by bubbling with argon gas. In another 100 mL two-neck flask, weigh 97.8 mg (373 μmol) of triphenylphosphine, 69.9 mg (367 μmol) of copper iodide, and 424 mg (366 μmol) of tetrakis (triphenylphosphine) palladium. Then, the above-mentioned bubbled mixed solution was added and stirred at 60 ° C. for 24 hours. The organic layer was extracted three times with ethyl acetate, neutralized with 2M hydrochloric acid and washed with saturated brine. The obtained organic layer was dehydrated by adding anhydrous magnesium sulfate, and after removing magnesium sulfate by filtration, ethyl acetate was removed by an evaporator and a diaphragm vacuum pump. Isolate by silica gel column chromatography using a developing solvent of hexane: dichloromethane = 6: 1 (v / v), remove the solvent with an evaporator, dry under reduced pressure with a diaphragm vacuum pump, and obtain 0.99 g (yield 47%). The target compound was obtained. From the ¹ H-NMR spectrum data of the obtained compound, it was confirmed that the obtained target compound was Compound 2. The ¹ H-NMR spectral data is shown below.
<Spectral data>
¹ H NMR (400 MHz, CDCl ₃ ) δ 7.35 (d, J = 8.4 Hz, 2H), 7.20 (d, J = 8.4 Hz, 2H), 2.92 (t, J = 7.6 Hz, 2H), 1.64 (tt , J = 7.2 and 7.6 Hz, 2H), 1.42 (tt, J = 7.2 and 7.2 Hz, 2H), 1.35‐1.22 (m, 4H), 0.88 (t, J = 6.4 Hz, 3H), 0.24 (s, 9H) ppm.

(3) Synthesis of 1-Ethynyl-4-hexylthiobenzene (Compound 3)
To a 100 mL eggplant-shaped flask, 0.980 g (3.37 mmol), 0.986 g (7.13 mmol) of potassium carbonate, 14 mL of a mixed solvent of THF: methanol = 1: 1 was added, and the mixture was stirred at room temperature for 3 hours. The organic layer was extracted three times with ethyl acetate and washed with saturated brine. The obtained organic layer was dehydrated by adding anhydrous magnesium sulfate, and after removing magnesium sulfate by filtration, ethyl acetate was removed by an evaporator and a diaphragm vacuum pump. Purification was performed by silica gel column chromatography using hexane as a developing solvent, and hexane was removed by an evaporator and a diaphragm vacuum pump to obtain 0.70 g (yield 95%) of the target compound. From the ¹ H-NMR spectrum data of the obtained compound, it was confirmed that the obtained target compound was Compound 3. The ¹ H-NMR spectral data is shown below.
<Spectral data>
¹ H NMR (400 MHz, CDCl ₃ ) δ 7.38 (d, J = 8.4 Hz, 2H), 7.22 (d, J = 8.4 Hz, 2H), 3.07 (s, 1H), 2.93 (t, J = 7.2 Hz , 2H), 1.65 (tt, J = 7.2 and 7.6 Hz, 2H), 1.43 (tt, J = 7.2 and 7.6 Hz, 2H), 1.36‐1.23 (m, 4H), 0.88 (t, J = 6.8 Hz, 3H) ppm.

(4) Synthesis of 1-Heptyl-4- [4- (4-hexylthiophenyl) -1,3-butadiynyl] benzene (6S-DPDA-7)
In a 100 mL flask, 0.200 g (0.916 mmol) of 1-ethynyl-4-hexylthiobenzene, 0.184 g (0.918 mmol) of 1-ethynyl-4-heptylbenzene, 3.10 mg (48.8 μmol) of copper, tetramethylethylenediamine ( TMEDA) (30 μL), chloroform: 1,4-dioxane = 3: 1 mixed solvent (4 mL) was added, and the mixture was stirred at 50 ° C. for 24 hours. The organic layer was extracted three times with chloroform, neutralized with 2M hydrochloric acid, and washed with saturated brine. The resulting organic layer was dehydrated by adding anhydrous magnesium sulfate, and after removing magnesium sulfate by filtration, chloroform was removed by an evaporator and a diaphragm vacuum pump. Silica gel column chromatography was performed using a developing solvent of hexane: chloroform = 9: 1, the target product was isolated, and the solvent was removed with an evaporator. Recrystallization was performed using methanol as a poor solvent and chloroform as a good solvent. ^From the spectrum data of ¹ H-NMR, ¹³ C-NMR, and FT-IR, the product obtained was 1-Heptyl-4- [4- (4-hexylthiophenyl) -1,3-butadiynyl] benzene (6S- DPDA-7) was confirmed.
<Spectral data>
6S-DPDA-7: ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.43 (d, J = 8.4 Hz, 2H), 7.41 (d, J = 8.4 Hz, 2H), 7.21 (d, J = 8.4 Hz, 2H), 7.14 (d, J = 8.4 Hz, 2H), 2.94 (t, J = 7.4 Hz, 2H), 2.60 (t, J = 7.6 Hz, 2H), 1.67 (tt, J = 7.4 and 7.8 Hz, 2H), 1.60 (tt, J = 7.6 and 7.6 Hz, 2H), 1.43 (tt, J = 7.4 and 7.8 Hz, 2H), 1.36-1.20 (m, 12H), 0.89 (t, J = 6.4 Hz, 3H ), 0.88 (t, J = 7.2 Hz, 3H) ppm.
¹³ C NMR (100 MHz, CDCl ₃ ) δ 144.6, 139.7, 132.7 × 2, 132.4 × 2, 128.6 × 2, 127.4 × 2, 118.9, 118.4, 82.1, 81.1, 74.3, 73.4, 36.0, 32.7, 31.8, 31.4 , 31.2, 29.2, 29.1, 28.9, 28.6, 22.7, 22.5, 14.1, 14.0 ppm. Yield: 31% (120 mg).
FTIR (KBr): 2212, 2141 cm ^-1 .

When the obtained 6S-DPDA-7 was set on a hot stage and the change of the phase state was observed with a polarizing microscope during the cooling process from the isotropic phase, it was observed that it became a nematic liquid crystal. Further, the final product was heated at a rate of temperature increase of 3 ° C./min from room temperature to a temperature exceeding the isotropic phase transition temperature in a nitrogen atmosphere using a differential scanning calorimeter, and then cooled at 3 ° C./min. It was detected on the basis of the _{T N,} and _{T Cr} to a change in the DSC curve. 6S-DPDA-7 of _{T N,} the _{T Cr} shown in Table 1.

  The obtained 6S-DPDA-7 was obtained by confirming the phase transition from the isotropic phase to the liquid crystal phase with a polarizing microscope and measuring the spectrum in the wavelength range of 400 to 900 nm at the liquid crystal phase temperature. The birefringence Δn was determined from the value.

  Specifically, first, light is applied from below the evaluation liquid crystal cell without enclosing the liquid crystal, and the transmitted interference light is measured with a spectroscope to obtain the thickness of the air layer from the following formula (1). The thickness of the air layer was defined as the cell gap.

ここで、上記数式（１）において、ｄはセルギャップ、ｍは整数、λは波長である。

Here, in the above formula (1), d is a cell gap, m is an integer, and λ is a wavelength.

  Next, 6S-DPDA-7 is sealed in a liquid crystal cell for evaluation whose cell gap is known, and a birefringent material produced by homogeneous alignment is sandwiched between two polarizers whose polarization axes are orthogonal to each other. Then, the wavelength value at which the measured spectral transmittance is maximized or minimized (the following formula (2)) and the retardation of the birefringent body at each wavelength (the following formula (3)) are expanded to the fourth order. Fitting was performed using the dispersion formula (Formula (4) below), and the birefringence Δn of 6S-DPDA-7 and the wavelength dispersion of retardation R were determined.

In Equation (2), I ₀ = initial transmitted light intensity, I = transmitted light intensity, A = amplitude intensity, d = cell gap, λ = wavelength, Δn = birefringence. In Equation (3), R = retardation, d = cell gap, Δn = birefringence, and in Equation (4), Δn = birefringence and λ = wavelength.

  The birefringence Δn of 6S-DPDA-7 thus obtained is shown in FIG.

Example 2 Synthesis of 1-Hexylthio-4- (4-phenyl-1,3-butadiyn-1-yl) benzene In Example 2, instead of 1-ethynyl-4-heptylbenzene in Example 1, ethynyl was used. A diacetylene derivative was synthesized in the same manner as in Example 1 except that benzene was used. The obtained diacetylene derivative was subjected to structural analysis by ¹ H-NMR and ¹³ C-NMR, and this final product was converted to the desired 1-Hexylthio-4- (4-phenyl-1,3-butadiyn-1 -yl) Confirmed to be benzene. In order to simplify the explanation, the present compound of Example 2 may be referred to as “6S-DPDA-0” as appropriate hereinafter.

Thus, in this example, a diacetylene derivative having the diphenyl diacetylene skeleton represented by the general formula (2) described above, one of which is an alkylthio group having 6 carbon atoms and no other end group. Got. The spectrum data of ¹ H-NMR, ¹³ C-NMR, and FT-IR are shown below.
<Spectral data>
¹ H NMR (400 MHz, CDCl ₃ ) δ 7.52 (d, J = 7.8 Hz, 2H), 7.42 (d, J = 8.8 Hz, 2H), 7.35 (dd, J = 7.0 and 7.0 Hz, 1H), 7.35 (dd, J = 7.8 and 7.0 Hz, 2H), 7.22 (d, J = 8.8 Hz, 2H), 2.94 (t, J = 7.6 Hz, 2H), 1.67 (tt, J = 7.2 and 7.6 Hz, 2H) , 1.44 (tt, J = 7.2 and 7.4 Hz, 2H), 1.36-1.24 (m, 4H), 0.89 (t, J = 6.8 Hz, 3H) ppm.
¹³ C NMR (100 MHz, CDCl ₃ ) δ 139.7, 139.6, 132.7 × 2, 132.4 × 2, 129.2 × 2, 127.4 × 2, 118.7, 118.4, 82.1, 81.2, 74.3, 73.4, 32.7, 31.4, 28.9, 28.6 , 22.5, 14.0 ppm. Yield: 22% (78 mg).
FTIR (KBr): 2214, 2147 cm ^-1

  Similarly to Example 1, the obtained 6S-DPDA-0 was subjected to observation with a polarizing microscope and differential scanning calorimetry to observe and measure the expression of the liquid crystal phase. The results are shown in Table 1.

Example 3 Synthesis of 1- [4- (4-Hexylthiophenyl) -1,3-butadiyn-1-yl] -4-methylbenzene
In Example 3, a diacetylene derivative was synthesized in the same manner as in Example 1 except that 1-ethynyl-4-methylbenzene was used instead of 1-ethynyl-4-heptylbenzene in Example 1. The obtained diacetylene derivative was subjected to structural analysis by NMR, and this final product was the target 1- [4- (4-Hexylthiophenyl) -1,3-butadiyn-1-yl] -4-methylbenzene. I confirmed that there was. In order to simplify the description, the compound of Example 3 may be referred to as “6S-DPDA-1” as appropriate hereinafter.

Thus, in this example, the diacetylene derivative having the diphenyl diacetylene skeleton represented by the general formula 2 described above, one terminal group of which is an alkylthio group having 6 carbon atoms, and the other terminal group is a methyl group. Got. The spectrum data of ¹ H-NMR, ¹³ C-NMR, and FT-IR are shown below.
<Spectral data>
¹ H NMR (400 MHz, CDCl ₃ ) δ 7.41 (d, J = 8.4 Hz, 2H), 7.41 (d, J = 8.4 Hz, 2H), 7.22 (d, J = 8.4 Hz, 2H), 7.14 (d , J = 8.4 Hz, 2H), 2.94 (t, J = 7.6 Hz, 2H), 2.37 (s, 3H), 1.67 (tt, J = 7.6 and 7.6 Hz, 2H), 1.43 (tt, J = 7.2 and 7.6 Hz, 2H), 1.36-1.27 (m, 4H), 0.89 (t, J = 6.8 Hz, 3H) ppm.
¹³ C NMR (100 MHz, CDCl ₃ ) δ 139.7, 139.6, 132.7 × 2, 132.4 × 2, 129.2 × 2, 127.4 × 2, 118.7, 118.4, 82.1, 81.2, 74.3, 73.4, 32.7, 31.3, 28.9, 28.6 , 22.5, 21.6, 14.0 ppm. Yield: 36% (136 mg).
FTIR (KBr): 2140 cm ^-1 .

  Similarly to Example 1, the obtained 6S-DPDA-1 was also observed with a polarizing microscope and differential scanning calorimetry, and observed and measured the expression of the liquid crystal phase. The results are shown in Table 1.

Example 4 Synthesis of 1-Ethyl-4- [4- (4-hexylthiophenyl) -1,3-butadiyn-1-yl] benzene
In Example 4, a diacetylene derivative was synthesized in the same manner as in Example 1 except that 1-ethynyl-4-ethylbenzene was used instead of 1-ethynyl-4-heptylbenzene in Example 1. The obtained diacetylene derivative was subjected to structural analysis by NMR, and this final product was converted to the desired 1-Ethyl-4- [4- (4-hexylthiophenyl) -1,3-butadiyn-1-yl] benzene It was confirmed that. In order to simplify the description, the compound of Example 4 may be referred to as “6S-DPDA-2” as appropriate hereinafter.

Accordingly, in this example, the diphenyl diacetylene skeleton represented by the general formula (2) described above is included, one end group is an alkylthio group having 6 carbon atoms, and the other end group is ethyl having 2 carbon atoms. A diacetylene derivative as a group was obtained. The spectrum data of ¹ H-NMR, ¹³ C-NMR, and FT-IR are shown below.
<Spectral data>
¹ H NMR (400 MHz, CDCl ³ ) δ 7.44 (d, J = 8.0 Hz, 2H), 7.41 (d, J = 8.0 Hz, 2H), 7.21 (d, J = 8.0 Hz, 2H), 7.17 (d , J = 8.0 Hz, 2H), 2.94 (t, J = 7.4 Hz, 2H), 2.66 (q, J = 7.6 Hz, 2H), 1.67 (tt, J = 7.4 and 7.4 Hz, 2H), 1.43 (tt , J = 7.0 and 7.4 Hz, 2H), 1.36-1.27 (m, 4H), 1.23 (t, J = 7.6 Hz, 3H), 0.89 (t, J = 6.6 Hz, 3H) ppm.
¹³ C NMR (100 MHz, CDCl ₃ ) δ 145.8, 139.7, 132.7 × 2, 132.5 × 2, 128.1 × 2, 127.4 × 2, 119.0, 118.4, 82.1, 81.1, 74.3, 73.4, 32.7, 31.3, 28.9 × 2 , 28.6, 22.5, 15.2, 14.0 ppm. Yield: 33% (129 mg).
FTIR (KBr): 2210, 2131 cm ^-1 .

  Similarly to Example 1, the obtained 6S-DPDA-2 was also observed with a polarizing microscope and differential scanning calorimetry to observe and measure the expression of the liquid crystal phase. The results are shown in Table 1.

Example 5 Synthesis of 1- [4- (4-Hexylthiophenyl) -1,3-butadiyny-1-yl] -4-propylbenzene
In Example 5, a diacetylene derivative was synthesized in the same manner as in Example 1 except that 1-ethynyl-4-propylbenzene was used instead of 1-ethynyl-4-heptylbenzene in Example 1. The obtained diacetylene derivative was subjected to structural analysis by NMR, and this final product was obtained as the target 1- [4- (4-Hexylthiophenyl) -1,3-butadiyny-1-yl] -4-propylbenzene. I confirmed that there was. In order to simplify the description, the compound of Example 5 may be referred to as “6S-DPDA-3” as appropriate hereinafter.

Thus, in this example, the diphenyl diacetylene skeleton represented by the general formula (2) described above is included, one terminal group is an alkylthio group having 6 carbon atoms, and the other terminal group is propyl having 3 carbon atoms. A diacetylene derivative as a group was obtained. The spectrum data of ¹ H-NMR, ¹³ C-NMR, and FT-IR are shown below.
<Spectral data>
¹ H NMR (400 MHz, CDCl ₃ ) δ 7.43 (d, J = 8.8 Hz, 2H), 7.41 (d, J = 8.4 Hz, 2H), 7.22 (d, J = 8.4 Hz, 2H), 7.15 (d , J = 8.8 Hz, 2H), 2.94 (t, J = 7.6 Hz, 2H), 2.59 (t, J = 7.6 Hz, 2H), 1.67 (tt, J = 7.6 and 7.6 Hz, 2H), 1.64 (tq , J = 7.2 and 7.6 Hz, 2H), 1.44 (tt, J = 7.4 and 7.6 Hz, 2H), 1.37‐1.22 (m, 4H), 0.94 (t, J = 7.2 Hz, 3H), 0.89 (t, J = 6.8 Hz, 3H) ppm.
¹³ C NMR (100 MHz, CDCl ₃ ) δ 144.3, 139.7, 132.7 × 2, 132.4 × 2, 128.7 × 2, 127.4 × 2, 119.0, 118.4, 82.1, 81.2, 74.3, 73.4, 38.1, 32.7, 31.4, 28.9 , 28.6, 24.3, 22.5, 14.0, 13.8 ppm. Yield: 34% (141 mg).
FTIR (KBr): 2137 cm ^-1 .

  Similarly to Example 1, the obtained 6S-DPDA-3 was also subjected to observation with a polarizing microscope and differential scanning calorimetry to observe and measure the expression of the liquid crystal phase. The results are shown in Table 1.

Example 6 Synthesis of 1-Butyl-4- [4- (4-hexylthiophenyl) -1,3-butadiyn-1yl] benzene
In Example 6, a diacetylene derivative was synthesized in the same manner as in Example 1 except that 1-ethynyl-4-butylbenzene was used instead of 1-ethynyl-4-heptylbenzene in Example 1. The obtained diacetylene derivative was subjected to structural analysis by NMR, and this final product was the target 1-Butyl-4- [4- (4-hexylthiophenyl) -1,3-butadiyn-1yl] benzene It was confirmed. In order to simplify the description, the compound of Example 6 may be referred to as “6S-DPDA-4” as appropriate hereinafter.

Accordingly, in this example, the diphenyl diacetylene skeleton represented by the general formula (2) described above is included, one terminal group is an alkylthio group having 6 carbon atoms, and the other terminal group is butyl having 4 carbon atoms. A diacetylene derivative as a group was obtained. The spectrum data of ¹ H-NMR, ¹³ C-NMR, and FT-IR are shown below.
<Spectral data>
¹ H NMR (400 MHz, CDCl ₃ ) δ 7.43 (d, J = 8.0 Hz, 2H), 7.41 (d, J = 8.4 Hz, 2H), 7.22 (d, J = 8.4 Hz, 2H), 7.15 (d , J = 8.0 Hz, 2H), 2.94 (t, J = 7.2 Hz, 2H), 2.62 (t, J = 7.6 Hz, 2H), 1.67 (tt, J = 7.2 and 7.2 Hz, 2H), 1.59 (tt , J = 7.6 and 7.6 Hz, 2H), 1.44 (tt, J = 7.2 and 7.2 Hz, 2H), 1.33 (tq, J = 6.8 and 7.6 Hz, 2H), 1.36-1.27 (m, 4H), 0.92 ( t, J = 6.8 Hz, 3H), 0.89 (t, J = 6.6 Hz, 3H) ppm.
¹³ C NMR (100 MHz, CDCl ₃ ) δ 144.6, 139.7, 132.7 × 2, 132.4 × 2, 128.6 × 2, 127.4 × 2, 118.9, 118.4, 82.1, 81.1, 74.3, 73.4, 35.7, 33.3, 32.7, 31.4 , 28.9, 28.6, 22.5, 22.3, 14.0, 13.9 ppm. Yield: 37% (159 mg).
FTIR (KBr): 2140 cm ^-1 .

  Similarly to Example 1, the obtained 6S-DPDA-4 was also observed with a polarizing microscope and differential scanning calorimetry, and observed and measured the expression of the liquid crystal phase. The results are shown in Table 1.

Example 7 Synthesis of 1- [4- (4-Hexylthiophenyl) -1,3-butadiyn-1yl] -4-pentylbenzene
In Example 7, a diacetylene derivative was synthesized in the same manner as in Example 1 except that 1-ethynyl-4-pentylbenzene was used instead of 1-ethynyl-4-heptylbenzene in Example 1. The obtained diacetylene derivative was subjected to structural analysis by NMR, and the final product was the target 1- [4- (4-Hexylthiophenyl) -1,3-butadiyn-1yl] -4-pentylbenzene. It was confirmed. In order to simplify the description, the compound of Example 7 may be referred to as “6S-DPDA-5” as appropriate hereinafter.

Accordingly, in this example, the diphenyl diacetylene skeleton represented by the general formula (2) described above is included, one terminal group is an alkylthio group having 6 carbon atoms, and the other terminal group is pentyl having 5 carbon atoms. A diacetylene derivative as a group was obtained. The spectrum data of ¹ H-NMR, ¹³ C-NMR, and FT-IR are shown below.
<Spectral data>
¹ H NMR (400 MHz, CDCl ₃ ) δ 7.43 (d, J = 8.4 Hz, 2H), 7.41 (d, J = 8.0 Hz, 2H), 7.22 (d, J = 8.0 Hz, 2H), 7.14 (d , J = 8.4 Hz, 2H), 2.94 (t, J = 7.6 Hz, 2H), 2.61 (t, J = 7.6 Hz, 2H), 1.67 (tt, J = 7.6 and 7.6 Hz, 2H), 1.59 (tt , J = 7.6 and 7.6 Hz, 2H), 1.43 (tt, J = 7.2 and 7.6 Hz, 2H), 1.38-1.25 (m, 8H), 0.89 (t, J = 6.8 Hz, 3H), 0.89 (t, J = 6.8 Hz, 3H) ppm.
¹³ C NMR (100 MHz, CDCl ₃ ) δ 144.6, 139.7, 132.7 × 2, 132.4 × 2, 128.6 × 2, 127.4 × 2, 118.9, 118.4, 82.1, 81.1, 74.3, 73.4, 36.0, 32.7, 31.4, 31.3 , 30.8, 28.9, 28.6, 22.5 × 2, 14.0 × 2 ppm. Yield: 34% (120 mg).
FTIR (KBr): 2136 cm ^-1 .

  Similarly to Example 1, the obtained 6S-DPDA-5 was observed with a polarizing microscope and differential scanning calorimetry to observe and measure the expression of the liquid crystal phase. The results are shown in Table 1.

Example 8 Synthesis of 1-Hexyl-4- [4- (4-hexylthiophenyl) -1,3-butadiyn-1-yl] benzene
In Example 8, a diacetylene derivative was synthesized in the same manner as in Example 1 except that 1-ethynyl-4-hexylbenzene was used instead of 1-ethynyl-4-heptylbenzene in Example 1. The obtained diacetylene derivative was subjected to structural analysis by NMR, and this final product was converted to the desired 1-Hexyl-4- [4- (4-hexylthiophenyl) -1,3-butadiyn-1-yl] benzene It was confirmed that. In order to simplify the description, the compound of Example 8 may be referred to as “6S-DPDA-6” as appropriate hereinafter.

Thus, in this example, the diphenyl diacetylene skeleton represented by the general formula (2) described above is included, one terminal group is an alkylthio group having 6 carbon atoms, and the other terminal group is a hexyl having 6 carbon atoms. A diacetylene derivative as a group was obtained. The spectrum data of ¹ H-NMR, ¹³ C-NMR, and FT-IR are shown below.
<Spectral data>
¹ H NMR (400 MHz, CDCl ₃ ) δ 7.43 (d, J = 8.4 Hz, 2H), 7.41 (d, J = 8.4 Hz, 2H), 7.22 (d, J = 8.4 Hz, 2H), 7.14 (d , J = 8.4 Hz, 2H), 2.94 (t, J = 7.2 Hz, 2H), 2.61 (t, J = 7.6 Hz, 2H), 1.67 (tt, J = 7.2 and 7.6 Hz, 2H), 1.60 (tt , J = 7.2 and 7.6 Hz, 2H), 1.44 (tt, J = 7.4 and 7.6 Hz, 2H), 1.36-1.25 (m, 10H), 0.89 (t, J = 6.8 Hz, 3H), 0.88 (t, J = 6.8 Hz, 3H) ppm.
¹³ C NMR (100 MHz, CDCl ₃ ) δ 144.6, 139.7, 132.7 × 2, 132.4 × 2, 128.6 × 2, 127.4 × 2, 118.9, 118.4, 82.1, 81.1, 74.3, 73.4, 36.0, 32.7, 31.7, 31.3 , 31.1, 28.9 × 2, 28.6, 22.6, 22.5, 14.1, 14.0 ppm. Yield: 27% (100 mg).
FTIR (KBr): 2212, 2141 cm ^-1 .

  Similarly to Example 1, the obtained 6S-DPDA-6 was also observed and measured for the expression of the liquid crystal phase by performing polarization microscope observation and differential scanning calorimetry. The results are shown in Table 1.

Example 9 Synthesis of 1- [4- (4-Hexylthiophenyl) -1,3-butadiyn-1yl] -4-octylbenzene
In Example 9, a diacetylene derivative was synthesized in the same manner as in Example 1 except that 1-ethynyl-4-octylbenzene was used instead of 1-ethynyl-4-heptylbenzene in Example 1. The obtained diacetylene derivative was subjected to structural analysis by NMR, and the final product was the target 1- [4- (4-Hexylthiophenyl) -1,3-butadiyn-1yl] -4-octylbenzene It was confirmed. In order to simplify the description, the compound of Example 9 may be referred to as “6S-DPDA-8” as appropriate hereinafter.

Thus, in this example, the diphenyl diacetylene skeleton represented by the general formula (2) described above is included, one terminal group is an alkylthio group having 6 carbon atoms, and the other terminal group is octyl having 8 carbon atoms. A diacetylene derivative as a group was obtained. The spectrum data of ¹ H-NMR, ¹³ C-NMR, and FT-IR are shown below.
<Spectral data>
¹ H NMR (400 MHz, CDCl ₃ ) δ 7.43 (d, J = 8.4 Hz, 2H), 7.41 (d, J = 8.4 Hz, 2H), 7.22 (d, J = 8.4 Hz, 2H), 7.14 (d , J = 8.4 Hz, 2H), 2.94 (t, J = 7.4 Hz, 2H), 2.60 (t, J = 7.2 Hz, 2H), 1.67 (tt, J = 7.0 and 7.4 Hz, 2H), 1.60 (tt , J = 7.0 and 7.2 Hz, 2H), 1.43 (tt, J = 7.0 and 7.2 Hz, 2H), 1.37‐1.21 (m, 14H), 0.89 (t, J = 6.8 Hz, 3H), 0.88 (t, J = 6.8 Hz, 3H) ppm.
¹³ C NMR (100 MHz, CDCl ₃ ) δ 144.6, 139.7, 132.7 × 2, 132.4 × 2, 128.6 × 2, 127.4 × 2, 118.9, 118.4, 82.1, 81.1, 74.3, 73.4, 36.0, 32.7, 31.9, 31.3 , 31.2, 29.4, 29.3, 29.2, 28.9, 28.6, 22.7, 22.5, 14.1, 14.0 ppm. Yield: 39% (152 mg).
FTIR (KBr): 2216, 2146 cm ^-1 .

  Similarly to Example 1, the obtained 6S-DPDA-8 was also observed with a polarizing microscope and differential scanning calorimetry, and observed and measured the expression of the liquid crystal phase. The results are shown in Table 1.

Example 10 Synthesis of 1-Dodecyl-4- [4- (4-hexylthiophenyl) -1,3-butadiyn-1-yl] benzene
In Example 10, a diacetylene derivative was synthesized in the same manner as in Example 1 except that 1-ethynyl-4-dodecylbenzene was used instead of 1-ethynyl-4-heptylbenzene in Example 1. The resulting diacetylene derivative was subjected to structural analysis by NMR, and this final product was converted to the desired 1-Dodecyl-4- [4- (4-hexylthiophenyl) -1,3-butadiyn-1-yl] benzene It was confirmed that. In order to simplify the description, the compound of Example 10 may be referred to as “6S-DPDA-12” as appropriate hereinafter.

Thus, in this example, the diphenyl diacetylene skeleton represented by the general formula (2) described above is included, one terminal group is an alkylthio group having 6 carbon atoms, and the other terminal group is 12 carbon atoms dodecyl. A diacetylene derivative as a group was obtained. The spectrum data of ¹ H-NMR, ¹³ C-NMR, and FT-IR are shown below.
<Spectral data>
¹ H NMR (400 MHz, CDCl ₃ ) δ 7.43 (d, J = 8.4 Hz, 2H), 7.41 (d, J = 8.4 Hz, 2H), 7.22 (d, J = 8.4 Hz, 2H), 7.14 (d , J = 8.4 Hz, 2H), 2.94 (t, J = 7.4 Hz, 2H), 2.60 (t, J = 7.6 Hz, 2H), 1.67 (tt, J = 7.4 and 7.4 Hz, 2H), 1.60 (tt , J = 7.0 and 7.6 Hz, 2H), 1.44 (tt, J = 7.4 and 7.4 Hz, 2H), 1.37-1.20 (m, 22H), 0.89 (t, J = 7.0 Hz, 3H), 0.88 (t, J = 7.0 Hz, 3H) ppm.
¹³ C NMR (100 MHz, CDCl ₃ ) δ 144.6, 139.7, 132.7 × 2, 132.4 × 2, 128.6 × 2, 127.4 × 2, 118.9, 118.4, 82.1, 81.1, 74.3, 73.4, 36.0, 32.7, 31.9, 31.4 , 31.2, 29.7 × 3, 29.6, 29.5, 29.4, 29.3, 28.9, 28.6, 22.7, 22.5, 14.1, 14.0 ppm. Yield: 27% (121 mg).
FTIR (KBr): 2211, 2141 cm ^-1 .

  Similarly to Example 1, the obtained 6S-DPDA-12 was also observed with a polarizing microscope and differential scanning calorimetry, and observed and measured the expression of the liquid crystal phase. The results are shown in Table 1.

Example 11 Synthesis of 1-Hexyloxy-4- [4- (4-hexylthiophenyl) -1,3-butadiynyl] benzene
In Example 11, a diacetylene derivative was synthesized in the same manner as in Example 1 except that 1-ethynyl-1,4-hexyloxybenzene was used instead of 1-ethynyl-4-heptylbenzene in Example 1. did. The obtained diacetylene derivative was subjected to structural analysis by NMR, and the final product was confirmed to be the target 1-Hexyloxy-4- [4- (4-hexylthiophenyl) -1,3-butadiynyl] benzene. confirmed. In order to simplify the explanation, the compound of Example 11 may be referred to as “6S-DPDA-O6” as appropriate hereinafter.

Thus, in this example, the diphenyl diacetylene skeleton represented by the general formula (2) described above is included, one terminal group is an alkylthio group having 6 carbon atoms, and the other terminal group is an alkoxy having 6 carbon atoms. A diacetylene derivative as a group was obtained. The spectrum data of ¹ H-NMR, ¹³ C-NMR, and FT-IR are shown below.
<Spectral data>
¹ H NMR (400 MHz, CDCl ₃ ) δ 7.45 (d, J = 8.8 Hz, 2H), 7.40 (d, J = 8.8 Hz, 2H), 7.21 (d, J = 8.8 Hz, 2H), 6.84 (d , J = 8.8 Hz, 2H), 3.96 (t, J = 6.4 Hz, 2H), 2.93 (t, J = 7.4 Hz, 2H), 1.78 (tt, J = 6.4 and 7.2 Hz, 2H), 1.67 (tt , J = 7.4 and 7.4 Hz, 2H), 1.45 (tt, J = 7.2 and 7.2 Hz, 2H), 1.43 (tt, J = 7.4 and 7.4 Hz, 2H), 1.38-1.25 (m, 8H), 0.91 ( t, J = 7.0 Hz, 3H), 0.89 (t, J = 7.0 Hz, 3H) ppm.
¹³ C NMR (100 MHz, CDCl ₃ ) δ 160.0, 139.5, 134.1 × 2, 132.7 × 2, 127.4 × 2, 118.6 × 2, 114.7, 113.5, 82.2, 80.9, 74.5, 72.7, 68.2, 32.7, 31.6, 31.3 , 29.1, 28.9, 28.6, 25.7, 22.6, 22.5, 14.0 × 2 ppm.
FTIR (KBr): 2139 cm ^-1 . Yield: 96 mg (25%).

  Similarly to Example 1, the obtained 6S-DPDA-O6 was also observed with a polarizing microscope and differential scanning calorimetry, and observed and measured the expression of the liquid crystal phase. The results are shown in Table 1.

  Table 1 is a table showing the behavior of the liquid crystal phase of each diphenyl diacetylene derivative (sample) obtained from the DSC measurement results in each of the above examples, that is, the phase transition temperature.

In Table 1, the samples of Examples 1 to 11 are displayed in order from the top, and each T _Cr (° C.), T _Sm (° C.), T _N (° C.) is associated with each sample name on the right side. Is displayed. In addition, the enthalpy of the transition is shown in parentheses on the right side of each phase transition temperature. When the phase transition temperature is not detected, “−” is displayed in Table 1.

  As can be seen from Table 1, the diacetylene derivatives of Examples 1 and 4 to 11 were shown to exhibit liquid crystallinity.

(Comparative Example 1)
A diacetylene derivative was synthesized in the same manner as in Example 1 except that 1-ethynyl-4-heptylbenzene was used instead of Compound 3 in Example 1. As a result, a diacetylene derivative having a diphenyl diacetylene skeleton represented by the general formula 2 and having both alkyl groups having 7 carbon atoms was obtained. In order to simplify the explanation, the diacetylene derivative of Comparative Example 1 is sometimes referred to as “7-DPDA-7” as appropriate below. The obtained 7-DPDA-7 was determined for birefringence Δn by the same method as in Example 1. The results are shown in FIG.

FIG. 2 is a graph showing the temperature dependence of the birefringence of the diacetylene derivatives of Example 1 and Comparative Example 1 at a measurement wavelength of 550 nm. The horizontal axis represents temperature (° C.), and the vertical axis represents birefringence (Δn). The black circle (●) indicates the birefringence in the nematic liquid crystal state of the diacetylene derivative (6S-DPDA-7) of Example 1, and the black triangle (▲) indicates the diacetylene derivative (7 -DPDA-7) shows the birefringence in the nematic liquid crystal state. As can be seen from FIG. 2, the diacetylene derivative of Example 1 has a wider temperature range for forming a nematic liquid crystal phase than the diacetylene derivative of Comparative Example 1, and is on the lower temperature side. The birefringence is also larger. For display applications, the birefringence is usually large when the birefringence is greater than about 0.1. However, the diacetylene derivative of Example 1 has a very large birefringence of 0.2 or more. It was shown to have refraction.

Claims (5)

A diacetylene derivative represented by the following general formula (1).

(In the formula, R ¹ is an optionally substituted alkyl group having 1 to 20 carbon atoms, an alkoxy group, or an optionally substituted alkenyl group having 2 to 20 carbon atoms, and R ² is a substituent. An optionally substituted alkyl group having 1 to 20 carbon atoms or an optionally substituted alkenyl group having 2 to 20 carbon atoms, A ¹ is an unsubstituted or halogen atom, cyano group, methyl group, ethyl group , A halogenated alkyl group, an aromatic ring group or a heterocyclic group which may be mono- or polysubstituted by a C 1-20 alkoxy group.) A ¹ is unsubstituted or an aromatic ring group which may be mono-substituted or poly-substituted by a halogen atom, a cyano group, a methyl group, an ethyl group, a halogenated alkyl group, or an alkoxy group having 1 to 20 carbon atoms. 2. The diacetylene derivative according to claim 1, wherein The diacetylene derivative according to claim 2, wherein A ¹ is a 1,4-phenylene group and has liquid crystallinity. The diacetylene derivative according to claim 3, wherein R ¹ is an alkyl group having ^{1 to} 16 carbon atoms which may have a substituent. The diacetylene derivative according to claim 3 or 4, wherein the alkyl group of R ¹ has an even number of carbon atoms.

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