CN113929701A - Dithieno [2, 3-b; 3',2' -d ] thiophene derivative and application thereof - Google Patents

Abstract

The invention discloses a dithieno [2, 3-b; 3',2' -d]Thiophene derivatives and their use, the derivatives being compounds of the general formula J:

wherein m and m' independently of one another represent 0 or 1 or 2; n and n' independently of one another represent 0 or 1; r^S1And R^S2Independently of one another, an alkyl group having 1 to 12 carbon atoms, a cyclopentyl group, a cyclobutyl group or a cyclopropyl group, wherein in addition, one or more-CH groups which are not adjacent to each other in the alkyl group are present₂The radicals may each be independently substituted by-C.ident.C-, -CH ═ CH-, -O-, -CO-, -COO-or-OCO-, and in which one or more H atoms may be substituted by F; and wherein one or more further H atoms may be substituted by F. The compounds are very useful for reducing the rotational viscosity gamma 1 of liquid crystal compositions for display applicationsBecomes faster and is also very suitable for increasing the dielectric anisotropy | Δ ∈ | of the liquid crystal composition to reduce the driving voltage for low power consumption display.

Description

Dithieno [2, 3-b; 3',2' -d ] thiophene derivative and application thereof

Technical Field

The invention belongs to the field of liquid crystal materials, relates to a liquid crystal compound, and particularly relates to a dithieno [2, 3-b; 3',2' -d ] thiophene derivatives and their use.

Background

Liquid crystal displays are widely used in mobile phones, smart phones, notebook computers, tablet computers, monitors, televisions, public displays, billboards, vehicle-mounted displays, industrial displays, and the like. As the liquid crystal display technology mode, a Twisted Nematic (TN) mode, a Super Twisted Nematic (STN) mode, a Guest Host (GH) mode, an in-plane switching (IPS) mode, a Fringe Field Switching (FFS) mode, an Optically Compensated Birefringence (OCB) mode, a voltage controlled birefringence (ECB) mode, a Vertical Alignment (VA) mode, a Ferroelectric Liquid Crystal (FLC), and the like are mainly included. The liquid crystal display driving method mainly includes a static driving method, a multiplex driving method, a simple matrix method, and an Active Matrix (AM) method in which driving is performed by a Thin Film Transistor (TFT), a Thin Film Diode (TFD), or the like. Among them, displays such as IPS type, FFS type, ECB type, VA type, and the like exhibit favorable characteristics when a liquid crystal composition having negative dielectric anisotropy (Δ ∈) (negative liquid crystal composition) is used.

Patent documents CN 105153112B, CN110831931, CN106045953A disclose a 4, 6-difluoro-dibenzothiophene derivative, patent documents CN101343279B and Journal of Organic Chemistry (2006),71(8),3264 disclose dithieno [2, 3-B; although the preparation method of 3',2' -d ] thiophene can be used in the field of liquid crystal, Tni and other parameters have poor performance and have limitation in application. In addition, the liquid crystal compounds have many defects in clearing point, low-temperature storage property, and the like.

Disclosure of Invention

In view of the disadvantages of the prior art, it is an object of the present invention to provide compounds which can be used as components of liquid-crystal compositions, in particular, which have a negative dielectric anisotropy Δ ∈, a high clearing point Tni, a low γ 1, and a low overall parameter γ 1/| Δ |, and which are particularly suitable for the simultaneous advantageous optimization of the individual application parameters of the liquid-crystal compositions. The method is particularly suitable for FFS, IPS and VA displays.

In order to achieve the purpose, the invention adopts the following technical scheme:

the present invention provides a compound of formula J:

wherein m and m' independently of one another represent 0 or 1 or 2; n and n' independently of one another represent 0 or 1;

R^S1and R^S2Independently of one another, an alkyl group having 1 to 12 carbon atoms, a cyclopentyl group, a cyclobutyl group or a cyclopropyl group, wherein in addition, one or more-CH groups which are not adjacent to each other in the alkyl group are present₂The radicals may each be independently substituted by-C.ident.C-, -CH ═ CH-, -O-, -CO-, -COO-or-OCO-, and in which one or more H atoms may be substituted by F;

namely, R^S1And R^S2Independently of one another, an alkyl group having 1 to 12 carbon atoms, a cyclopentyl group, a cyclobutyl group or a cyclopropyl group; or, R^S1And R^S2Independently of one another, an alkyl group having 1 to 12 carbon atoms, a cyclopentyl group, a cyclobutyl group or a cyclopropyl group, wherein one or more-CH groups not adjacent to each other in the alkyl group are present₂-each independently is substituted with-C ≡ C-, -CH ═ CH-, -O-, -CO-, -COO-, or-OCO-; or, R^S1And R^S2Independently of one another, represents alkyl having 1 to 12 carbon atoms, cyclopentyl, cyclobutyl or cyclopropyl, wherein one or more H atoms of these radicals are substituted by F; or, R^S1And R^S2Independently of one another, an alkyl group having 1 to 12 carbon atoms, a cyclopentyl group, a cyclobutyl group or a cyclopropyl group, wherein one or more-CH groups not adjacent to each other in the alkyl group are present₂-each independently is substituted with-C ≡ C-, -CH ═ CH-, -O-, -CO-, -COO-, or-OCO-, and one or more H atoms in these groups are substituted with F;

A^S1and A^S2Independently of one another, represent a group (i.e. a), b), c) selected from:

a)1, 4-phenylene in which one or two CH groups may be replaced by N and in which one or more H atoms may be replaced by a group L;

that is, a) is 1, 4-phenylene; or, 1, 4-phenylene in which one or two CH groups are replaced by N; or, 1, 4-phenylene in which one or more H atoms are replaced by a group L; or, 1, 4-phenylene in which one or two CH groups are replaced by N and in which one or more H atoms are replaced by a group L;

b) from the group consisting of trans-1, 4-cyclohexylene and 1, 4-cyclohexenylene, one or more of themA non-adjacent CH₂The groups may be replaced by-O-and/or-S-, and wherein one or more H atoms may be replaced by F;

that is, b) is a group consisting of trans-1, 4-cyclohexylene and 1, 4-cyclohexenylene; or, b) is a group consisting of trans-1, 4-cyclohexylene and 1, 4-cyclohexenylene, wherein one or more non-adjacent CH groups₂The radicals being replaced by-O-and/or-S-; or, b) is a group consisting of trans-1, 4-cyclohexylene and 1, 4-cyclohexenylene, wherein one or more H atoms are replaced by F; or, b) is a group consisting of trans-1, 4-cyclohexylene and 1, 4-cyclohexenylene, wherein one or more non-adjacent CH groups₂The radicals being replaced by-O-and/or-S-, and wherein one or more H atoms are replaced by F;

c) a group consisting of tetrahydropyran-2, 5-diyl, 1, 3-dioxane-2, 5-diyl, tetrahydrofuran-2, 5-diyl, cyclobutane-1, 3-diyl, piperidine-1, 4-diyl, silole-2, 5-diyl, thiophene-2, 5-diyl and selenophene-2, 5-diyl, each of which may be further mono-or polysubstituted with an L group;

that is, c) is a group consisting of tetrahydropyran-2, 5-diyl, 1, 3-dioxane-2, 5-diyl, tetrahydrofuran-2, 5-diyl, cyclobutane-1, 3-diyl, piperidine-1, 4-diyl, silole-2, 5-diyl, thiophene-2, 5-diyl and selenophene-2, 5-diyl; or, c) is a group consisting of tetrahydropyran-2, 5-diyl, 1, 3-dioxan-2, 5-diyl, tetrahydrofuran-2, 5-diyl, cyclobutane-1, 3-diyl, piperidine-1, 4-diyl, silole-2, 5-diyl, thiophene-2, 5-diyl and selenophene-2, 5-diyl, each of which is further mono-or polysubstituted by a group L;

the L groups independently represent F, Cl, CN, SCN, SF₅Or straight-chain or branched, in each case optionally fluorinated, alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12C atoms;

Z^S1and Z^S2Independently of one another represent-CH₂O-、-OCH₂-、-CF₂O-、-OCF₂-、-(CO)O-、-O(CO)-、-CH₂CH₂-、-CF₂-CF₂-、-CF_2-CH₂-、-CH₂-CF₂-、-CH＝CH-、-CF＝CF-、-CF＝CH-、-CH＝CF-、-C≡C-、-O-、-S-。

Preferably, R^S1And R^S2Independently of one another, represent unsubstituted alkyl having 1 to 9 carbon atoms, or alkenyl, alkenyloxy having 2 to 8 carbon atoms, in each case optionally one or more H atoms may be substituted by F.

In formula J, the parameter m is preferably 0 or 1, m 'is preferably 0 or 1, and the sum of m + m' is preferably 1;

the sum of the parameters n + n' is preferably 0 or 1; the sum of the parameters n + n' is preferably 1;

R^S1and R^S2Preferably each independently of the others, represents an alkyl radical having 1 to 8 carbon atoms or an alkenyl radical having 2 to 8 carbon atoms, respectively, where R^S1And R^S2The groups are preferably different;

R^S1and R^S2Further preferably each independently of the other represents an alkyl radical having in each case 2 to 8C atoms, where R^S1And R^S2The groups are preferably different.

In the general formula J, A^S1And A^S2Preferably independently represent a group selected from:

further preferred is from

Z^S1Preferably represents-O-, -S-, -CH₂O-or-CF₂O-；

Z^S2Preferably represents-O-, -S-, -OCH₂-or-OCF₂-；

L preferably represents F, Cl, -CF₃Or an alkyl or alkoxy group having 1, 2 or 3 carbon atoms.

Further preferred, the compound of formula J is selected from the group consisting of sub-formulae J-1, J-2, J-3 and J-4:

in the formula, R^S1、R^S2、A^S1、Z^S1Have the meaning as defined above for the general formula J.

Further preferred, the compound of sub-formula J-1 is preferably selected from compounds of formulae J-1-1 to J-1-11:

in the formula, R^S1、R^S2Have the meaning as defined above for the general formula J.

Further preferred, the compound of sub-formula J-2 is preferably selected from compounds of formulae J-2-1 to J-2-10:

in the formula, R^S1、R^S2Have the meaning as defined above for the general formula J.

The compounds have a clearly negative dielectric anisotropy (. DELTA.. di-elect cons.) and are therefore particularly suitable for liquid-crystalline compositions for VA, FFS, IPS-TFT displays. The compounds according to the invention preferably have a value of Δ ε.ltoreq.5, more preferably Δ ε.ltoreq.8 and particularly preferably Δ ε.ltoreq.12. They show good miscibility with conventional substances used in liquid crystal compositions for displays, i.e. they have good solubility therein. In addition the rotational viscosity of the compounds and the resulting liquid crystal compositions is also advantageously low.

Other physical, physicochemical or electrooptical parameters of the compounds according to the invention are also advantageous for the use of the compounds in liquid-crystalline compositions. Liquid crystal compositions comprising these compounds have in particular a wide nematic phase range and good low temperature and long-term stability as well as a sufficiently high clearing point. The low melting point of the compounds according to the invention indicates a favorable mixing behavior of the composition.

The following reference schemes illustrate particularly suitable synthetic routes for the compounds according to the invention. In the following scheme, the substituent R^S1、R^S2Have the meaning as described for the formula J.

The reaction schemes shown above should be considered as illustrative only. The skilled person will be able to carry out corresponding variations of the presented syntheses, and also follow other suitable synthetic routes to obtain compounds of general formula J. The present invention also includes, in one embodiment, one or more methods of preparing compounds of formula J according to the synthetic schemes depicted above.

The compounds of formula J can be used in liquid crystal compositions.

The liquid crystal composition is a liquid crystal composition comprising at least two liquid crystal compounds, and the liquid crystal compounds comprise at least one compound with a general formula J.

Compared with the prior art, the invention has the following beneficial effects:

3, 4-difluoro-dithieno [2, 3-b; 3',2' -d]Thiophene derivatives can be used as components of liquid crystal compositions having negative dielectric anisotropy (Delta)ε), exhibit large birefringence (Δ n), small rotational viscosity (γ 1), high clearing point (Tni), low overall parameter γ 1/| Δ ε |. Wherein A is^S1、A^S2The group can optimize Tni to improve the working temperature width performance, Z^S1、Z^S2The group can improve the compatibility in the composition and show more excellent low-temperature storage performance. The compound is very suitable for reducing the rotational viscosity gamma 1 of the liquid crystal composition to enable the response speed of display application to be faster, and is also very suitable for improving the dielectric anisotropy | delta epsilon | of the liquid crystal composition to reduce the driving voltage to realize low-energy consumption display. In addition, the liquid crystal composition has excellent compatibility, long low-temperature storage time, easy adjustment of high Tni and wide working temperature range. The method is particularly suitable for FFS, IPS and VA displays.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

The starting materials are commercially available from the open literature unless otherwise specified.

According to the conventional detection method in the field, various performance parameters of the liquid crystal compound are obtained through linear fitting, wherein the specific meanings of the performance parameters are as follows:

Δ n: refractive index anisotropy at 25 degrees Celsius (C.);

Δ ε: dielectric anisotropy at 25 degrees Celsius (C.);

γ 1: rotational viscosity (mPas) at 25 ℃ (. degree.C.).

Tni: clearing point (. degree. C.), temperature at which the nematic phase of the liquid crystal changes to the isotropic phase.

Low temperature storage (-30 ℃): the liquid crystal composition containing 10% of the compound of the present invention was stored at-30 ℃ for a continuous storage time in which no crystallization (precipitation) was observed.

Δ ∈, Δ n, γ 1, Tni of the compounds according to the invention were obtained by linear extrapolation of a liquid-crystal mixture consisting of 5 to 10% of the respective compound according to the invention and 90 to 95% of a liquid-crystal composition precursor mixed in a total amount of 100%.

Example 1

This example provides a compound, 3, 4-difluoro-dithieno [2, 3-b; 3',2' -d ] thiophene derivative J-1-4(TM 1):

the synthesis of compound J-1-4(TM1) was as follows:

step 1:

2-Methoxythiophene (Compound 1) (30g, 0.262mol) was dissolved in n-pentanol (80mL) and toluene (60mL), and NaHSO was added₄(1g) After refluxing with mixing and distilling off an azeotrope of methanol and toluene (12mL), the residue was washed with a sodium carbonate solution, dried and fractionally distilled to give 2-n-pentyloxythiophene compound 2(36g) in 77% yield.

Step 2:

2-n-pentyloxythiophene (Compound 2) (48g, 0.27mol) was dissolved in 125mL of methylene Chloride (CH)₂C_l2) N-bromosuccinimide (NBS, 96g, 0.54mol) was added under argon protection at 10 ℃ and stirred to react for 1 hour, the reaction solution was transferred to a chloroform solution to be washed with water, the organic phase was dried, and the residue was subjected to silica gel column chromatography to isolate compound 3(102.9g) in 90% yield after distilling the solvent.¹H-NMR(400MHz；CDCl₃；25℃)δ＝0.99(s,3H),δ＝1.39(s,4H),δ＝1.77(s,2H),δ＝4.05(s,2H),6.40(s,1H)ppm。

And step 3:

compound 3(23.5g, 70mmol) was dissolved in 150mL of anhydrous tetrahydrofuran (THT), 48mL of a 1.6N-butyllithium (N-BuLi, 80mmol, 1.1eq.) solution in diethyl ether was gradually added dropwise at-78 ℃ under argon protection, and the reaction was stirred at this temperature for 1 hour, then 10.7mL of trimethylsilicon chloride (80mmol, 1.1eq.) was added at this temperature and reacted at the same temperature for 1 hour. After the reaction solution was returned to room temperature, 300ml of water was added and the organic phase was extracted with 150ml of X3 ether, and after drying and evaporation of the solvent, a crude product was obtained which was analyzed by silica gel column chromatography to obtain Compound 4(16.57g) in a yield of 72%.¹H-NMR(400MHz；CDCl₃；25℃)0.27(s,9H),δ＝0.90(s,3H),δ＝1.39(s,4H),δ＝1.77(s,2H),δ＝4.05(s,2H),6.59(s,1H)ppm；FAB-MS m/z:320(M+)。

And 4, step 4:

compound 4(21.2g, 66mmol) was dissolved in 250ml of anhydrous tetrahydrofuran (THT), 41ml of a solution of 1.6N-butyllithium (N-BuLi, 68.9mmol, 1.05eq.) in diethyl ether was gradually added dropwise at-78 ℃ under argon protection, and the reaction was stirred at this temperature for 1 hour. Then adding fluorinating agent (PhSO)₂)₂NF (21.7g, 68.8mmol) and reacted at-78 deg.C for 30 min. And (3) after the reaction solution returns to the room temperature, adding HCl solution for quenching, washing and extracting, separating an organic phase, evaporating the solvent from the organic phase to obtain a crude product, and performing silica gel column chromatography analysis to obtain the compound 5(16.5) with the yield of 78%. 1H-NMR (400 MHz; CDCl)₃；25℃)0.31(9H,s),δ＝0.90(s,3H),δ＝1.39(s,4H),δ＝1.77(s,2H),δ＝4.05(s,2H),6.40(s,1H)ppm；FAB-MS m/z:260(M+)。

And 5:

compound 5(30g, 0.115mol)) Dissolved in 100mL of methylene Chloride (CH)₂Cl₂) N-bromosuccinimide (NBS, 20.5g, 0.115mol) was added under argon protection at 10 ℃ and stirred to react for 1 hour, the reaction solution was transferred to a chloroform solution and washed with water, the organic phase was dried, and the residue was subjected to silica gel column chromatography after distilling the solvent to isolate compound 6(35.8g) in 92% yield.¹H-NMR(400MHz；CDCl₃；25℃)0.32(9H,s),δ＝0.90(s,3H),δ＝1.39(s,4H),δ＝1.77(s,2H),δ＝4.05(s,2H)ppm；FAB-MS m/z:338(M+)。

Step 6:

compound 6(20g, 59mmol) was dissolved in 60mL of dichloromethane (CH)₂Cl₂) To the reaction solution, Trifluoroacetic acid (TFA, 5mL) was added dropwise thereto, and the reaction was stirred at room temperature for 10min, quenched with water, and then the organic phase was extracted, washed with water, dried, and the solvent was distilled off to obtain compound 7(15.5g) in 99% yield. 1H-NMR (400 MHz; CDCl)₃；25℃)δ＝0.90(s,3H),δ＝1.39(s,4H),δ＝1.77(s,2H),δ＝4.05(s,2H),δ＝6.05(s,1H)ppm；FAB-MS m/z:266(M+)。

And 7:

compound 7(27g, 101mmol) was dissolved in 100ml of anhydrous tetrahydrofuran (THT), 60ml of a 1.6N-butyllithium (N-BuLi, 110mmol, 1.1eq.) solution in diethyl ether was gradually added dropwise at-78 ℃ under argon atmosphere, and the reaction was stirred at this temperature for 1 hour, after which Bu was added at this temperature₃SnCl (29.5mL, 110mmol, 1.1eq.) and the reaction stirred at the same temperature for 1 hour. The reaction solution was returned to room temperature and then quenched with water, and the organic phase was extracted, washed with water, dried, and concentrated to give compound 8(40.6g) in 85% yield. 1H-NMR (400 MHz; CDCl)₃；25℃)0.90-0.92(m,12H),δ＝1.33-1.39(m,10H),δ＝1.58-1.63(m,12H),δ＝1.77(s,2H),δ＝4.05(s,2H),6.40(s,1H)ppm；FAB-MS m/z:478(M+)。

And 8:

compound 8(15g, 31.4mmol) and 3-fluoro-4-bromo-thiophene (4.74g, 26.2mol) and Pd (PPh)₃)₂Cl₂(541mg, 0.771mmol) was dissolved in 30mL of anhydrous DMF solvent, the reaction was stirred at 80 ℃ under argon for 3 hours, and after the reaction solution was cooled to room temperature, aqueous KF solution was added and stirred overnight. Extraction, washing with water, drying and passing through n-hexane silica gel column gave compound 9(6.8g) in 90% yield.¹H-NMR(400MHz；CDCl₃；25℃)0.90(s,3H),δ＝1.39(m,4H),δ＝1.77(s,2H),δ＝4.05(s,2H),6.35(s,1H),6.67(s,1H),7.78(s,1H)ppm；FAB-MS m/z:288(M+)。

And step 9:

compound 9(28.8g, 0.100mol) was dissolved in 100mL of methylene Chloride (CH)₂Cl₂) N-bromosuccinimide (NBS, 35.7g, 0.200mol) was added under argon protection at 10 ℃ and stirred to react for 1 hour, the reaction solution was transferred to a chloroform solution and washed with water, the organic phase was dried, and the residue was subjected to silica gel column chromatography after distilling the solvent to isolate compound 10(43.7g) with a yield of 98%.¹H-NMR(400MHz；CDCl₃；25℃)0.90(s,3H),δ＝1.39(m,4H),δ＝1.77(s,2H),δ＝4.05(s,2H),6.56(s,1H)ppm；FAB-MS m/z:446(M+)。

Step 10:

compound 10(4.46g, 10mmol) was dissolved in 50ml of anhydrous ether, the temperature was lowered to-78 ℃, t-butyllithium (t-BuLi,23mmol), reacting at-78 deg.C for 2 hr, and adding anhydrous (PhSO)₂)₂S (10.5mmol), the temperature was slowly raised to room temperature, and the mixture was stirred overnight. Adding water to quench the reaction, adding ether for extraction, combining organic phases, adding saturated NaCl, washing by distilled water and drying to obtain a crude product. The crude product was isolated by silica gel column chromatography to give Compound 11(1.9g) in 60% yield.¹H-NMR(400MHz；CDCl₃；25℃)0.90-0.97(m,6H),δ＝1.38-1.47(m,6H),δ＝1.74-1.77(m,4H),δ＝4.05(s,4H)ppm；FAB-MS m/z:318(M+)。

Step 11:

compound 11(31.8g, 0.100mol) was dissolved in 100mL of dichloromethane (CH2Cl2), N-bromosuccinimide (NBS, 35.7g, 0.200mol) was added under argon shielding at 10 ℃ and the reaction was stirred for 1 hour, the reaction solution was transferred to a chloroform solution and washed with water, the organic phase was dried, and the residue after distillation of the solvent was subjected to silica gel column chromatography to isolate compound 10(39g) in 98% yield.¹H-NMR(400MHz；CDCl₃；25℃)0.90(s,3H),δ＝1.39(m,4H),δ＝1.77(s,2H),δ＝4.05(s,2H)ppm；FAB-MS m/z:396(M+)。

Step 12:

compound 12(8g, 0.020mol), p-3-n-propylphenylboronic acid (3.3g), PdCl₂(PPh₃)₂(0.1g)，K₂CO₃(5.5g)60mL of DMF, 20mL of deionized water, and heating under argon for 3 hours. The reaction mixture was washed with water, the organic phase was dried, the solvent was distilled off, and the residue was subjected to silica gel column chromatography to give Compound J-1-4(TM1) (7.0g) in 80% yield¹H-NMR(400MHz；CDCl₃；25℃)0.90-0.94(m,6H),δ＝1.39(m,4H),δ＝1.64(s,2H),δ＝1.77(s,2H),δ＝2.61(s,2H),δ＝4.05(s,2H),δ＝7.32(s,2H),δ＝7.77(s,2H)ppm；FAB-MS m/z:436(M+)。

The performance parameters of J-1-4(TM1) were Δ ∈ -10.5, Δ n ═ 0.211, and rotational viscosity (γ 1) ═ 115.

Example 2

The following compounds were prepared in analogy to the synthetic procedure of example 1:

the performance parameters are Δ ∈ -11, Δ n ═ 0.201, and rotational viscosity (γ 1) ═ 119.

Example 3

The following compounds were prepared in analogy to the synthetic procedure of example 1:

the performance parameters are Tni equal to 105 ℃, Δ ∈ -7, Δ n equal to 0.220, rotational viscosity (γ 1) equal to 103, γ 1/| Δ ∈ | equal to 14.7, and low-temperature storage time (-30 ℃): 360 hr.

Example 4

The following compounds were prepared in analogy to the synthetic procedure of example 1:

the performance parameters are Tni ═ 112 ℃, Δ ∈ ═ 10.5, Δ n ═ 0.188, rotational viscosity (γ 1) ═ 95, γ 1/| Δ ∈ | > 9.04, and low-temperature storage time (-30 ℃): 360 hr.

Example 5

The following compounds were prepared in analogy to the synthetic procedure of example 1:

the performance parameters are Tni ═ 108 ℃, Δ ∈ ═ 15, Δ n ═ 0.195, rotational viscosity (γ 1) ═ 132, γ 1/| Δ | _ 8.8, and low-temperature storage time (-30 ℃): 360 hr.

Although the invention has been described in detail hereinabove with respect to a general description and specific embodiments thereof, it will be apparent to those skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.

Claims (10)

1. A compound characterized by having, in a first aspect,

the compound is of the general formula J:

wherein m and m' independently of one another represent 0 or 1 or 2; n and n' independently of one another represent 0 or 1;

R^S1and R^S2Independently of one another, an alkyl group having 1 to 12 carbon atoms, a cyclopentyl group, a cyclobutyl group or a cyclopropyl group, wherein in addition, one or more-CH groups which are not adjacent to each other in the alkyl group are present₂The-groups may each be independently substituted by-C ≡ C-, -CH ═ CH-, -O-, -CO-, -COO-or-OCO-, and wherein one or more H atoms may be substituted by F.

A^S1And A^S2Independently of one another, represent a group selected from:

a)1, 4-phenylene in which one or two CH groups may be replaced by N and in which one or more H atoms may be replaced by a group L;

b) trans-1, 4-cyclohexylene and 1, 4-cyclohexenylene, in which one or more non-adjacent CH groups₂The groups may be replaced by-O-and/or-S-, and wherein one or more H atoms may be replaced by F;

c) from tetrahydropyran-2, 5-diyl, 1, 3-diyl

Alkane-2, 5-bisA group consisting of a tetrahydrofuran-2, 5-diyl group, a cyclobutane-1, 3-diyl group, a piperidine-1, 4-diyl group, a silol-2, 5-diyl group, a thiophene-2, 5-diyl group and a selenophene-2, 5-diyl group, each of which may be further mono-or polysubstituted with an L group;

the L groups independently represent F, Cl, CN, SCN, SF₅Or straight-chain or branched, in each case optionally fluorinated, alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12C atoms;

Z^S1and Z^S2Independently of one another represent-CH₂O-、-OCH₂-、-CF₂O-、-OCF₂-、-(CO)O-、-O(CO)-、-CH₂CH₂-、-CF₂-CF₂-、-CF_2-CH₂-、-CH₂-CF₂-、-CH＝CH-、-CF＝CF-、-CF＝CH-、-CH＝CF-、-C≡C-、-O-、-S-。

2. The compound of claim 1,

R^S1and R^S2Independently of one another, represent unsubstituted alkyl having 1 to 9 carbon atoms, or alkenyl, alkenyloxy having 2 to 8 carbon atoms, in each case optionally one or more H atoms may be substituted by F.

3. The compound of claim 1,

the parameter m is 0 or 1, m 'is 0 or 1 and the sum of m + m' is 1;

the sum of the parameters n + n' is 0 or 1;

R^S1and R^S2Each independently of the other represents an alkyl radical having 1 to 8 carbon atoms or an alkenyl radical having 2 to 8 carbon atoms, where R^S1And R^S2The groups are preferably different;

in the general formula J, A^S1And A^S2Independently represent a group selected from:

Z^S1represents-O-, -S-, -CH₂O-or-CF₂O-；

Z^S2represents-O-, -S-, -OCH₂-or-OCF₂-；

L represents F, Cl, -CF₃Or an alkyl or alkoxy group having 1, 2 or 3 carbon atoms.

4. A compound according to claim 3,

the sum of the parameters n + n' is 1;

R^S1and R^S2Each independently of the other represents an alkyl radical having 2 to 8C atoms, where R^S1And R^S2The groups are preferably different.

5. A compound according to claim 3,

in the general formula J, A^S1And A^S2Independently represent a group selected from:

6. the compound according to any one of claims 1 to 5,

the compound of formula J is selected from the group consisting of sub-formulae J-1, J-2, J-3, and J-4:

in the formula, R^S1、R^S2、A^S1、Z^S1Has the same as the above forThe meaning as defined for formula J.

7. The compound of claim 6,

compounds of sub-formula J-1 are preferably selected from compounds of formulae J-1-1 to J-1-11:

in the formula, R^S1、R^S2Have the meaning as defined above for the general formula J.

8. The compound of claim 6,

the compound of sub-formula J-2 is preferably selected from compounds of formulae J-2-1 to J-2-10:

in the formula, R^S1、R^S2Have the meaning as defined above for the general formula J.

9. Use of one or more of the compounds according to any of claims 1 to 8 in liquid crystal compositions.

10. Use according to claim 9, wherein the liquid crystal composition is a liquid crystal composition comprising at least two liquid crystal compounds comprising at least one compound of formula J.