Alkene-containing bis(diphenylacetylene) liquid crystal compounds and related liquid crystal compositions

Abstract

This invention discloses an alkene-containing bis(diphenylacetylene) liquid crystal compound and related liquid crystal compositions. The structure of the liquid crystal compound is shown in general formula I, wherein R is hydrogen, fluorine, or an alkyl group having 1 to 5 carbon atoms, wherein the hydrogen atom on the carbon atom can be replaced by fluorine; Y is H, F, Cl, CN, NCS, CF3, OCF2H, OCF3, an alkyl group having 1 to 10 carbon atoms, an alkoxy group, or an alkenyl or alkenoxy group having 2 to 10 carbon atoms; X1 to X3 are H, F, Cl, CH3, C2H5, CF3, OCF3, and CN. The liquid crystal composition comprises a liquid crystal compound with the structure shown in general formula I. The alkene-containing bis(diphenylacetylene) liquid crystal compound of this invention has superior liquid crystal phase transition temperature characteristics, higher birefringence, lower rotational viscosity, and higher dielectric tunability. It is particularly suitable as a raw material for the fabrication of microwave antennas and liquid crystal optical devices.

Description

Technical Field

[0001] This invention belongs to the field of liquid crystal material technology, specifically relating to a bis(diphenylacetylene) liquid crystal compound containing an olefin chain, a liquid crystal composition, a liquid crystal high-frequency component, and a liquid crystal optical element. Background Technology

[0002] Liquid crystal materials are widely used in optoelectronic display devices, such as various LCD TVs, desktop LCD monitors, and mobile display terminals. In recent years, with the continuous development of microwave and terahertz communication, optical communication, and laser phased array technologies, there has been an urgent demand for liquid crystal materials with high birefringence. The higher the birefringence (Δn) of a liquid crystal, the greater its dielectric anisotropy in the microwave (1-100G) and terahertz bands. Furthermore, in liquid crystal devices such as optical communication and laser phased arrays, using liquid crystals with high birefringence (Δn) can significantly shorten the response time while maintaining the optical phase modulation.

[0003] To improve the birefringence of liquid crystal materials, it is necessary to introduce structures with long conjugated chains into the liquid crystal molecules. For example, the molecular backbone can adopt long conjugated structures of biphenyl, terphenyl, tetraphenyl, and diphenylacetylene. Liquid crystal molecules containing alkyne bonds (-C≡C-) have high polarizability anisotropy, thus resulting in high birefringence. In particular, bis(diphenylacetylene) liquid crystal compounds have extremely high birefringence and show great promise for applications in microwave devices and optical components.

[0004] For example, patent CN102510891A discloses a liquid crystal composition with a bis(diphenylacetylene) structure and its application in microwave devices. The composition based on the bis(diphenylacetylene) liquid crystal exhibits high dielectric tunability and low dielectric loss, demonstrating excellent microwave dielectric properties.

[0005] Although bis(diphenylacetylene) liquid crystals have high birefringence, they also have relatively high melting points and poor low-temperature compatibility. To lower the melting point and improve compatibility, the paper "Synthesis of laterally substituted bistolane liquid crystals. Liquid Crystals, 2000, 27(2): 283-287" reported the introduction of bulky groups, such as lateral ethyl groups, into the lateral side of the molecule to obtain low-melting-point liquid crystal compounds; however, this resulted in a decrease in both birefringence and clearing point. Therefore, further research and development of liquid crystal materials that simultaneously possess high birefringence and high clearing point are needed.

[0006] Furthermore, for microwave devices and optical components, the lowest possible viscosity is desirable to improve response speed. However, for high birefringence liquid crystal materials, the strong π-π interactions between molecules result in high viscosity. Moreover, as the birefringence of liquid crystal molecules increases, the viscosity also increases significantly, creating a contradiction that currently constrains the technical specifications of high birefringence liquid crystal materials.

[0007] To further meet the performance requirements of microwave, optical and other components, it is urgent to research and develop novel liquid crystal molecular structures that simultaneously possess high birefringence, wide nematic phase temperature range, low viscosity and good compatibility. Summary of the Invention

[0008] In order to overcome the defects or deficiencies in the prior art, the present invention provides a novel bis(diphenylacetylene) liquid crystal compound containing an olefin chain.

[0009] To achieve the above objectives, the olefin-containing bis(diphenylacetylene) liquid crystal compound structure provided by this invention is shown in general formula I:

[0010]

[0011] In Formula I: R is hydrogen and an alkyl group having 1 to 5 carbon atoms, wherein the hydrogen atom on the carbon atom can be replaced by fluorine; Y is H, F, Cl, CN, NCS, CF3, OCF2H, OCF3, alkyl with 1 to 10 carbon atoms, alkoxy with 1 to 10 carbon atoms, alkenyl with 2 to 10 carbon atoms, or alkenyl alkoxy with 2 to 10 carbon atoms; X1~X3 are H, F, Cl, CH3, C2H5, CF3, OCF3 or CN.

[0012] The preferred structure of the olefin-containing bis(diphenylacetylene) liquid crystal compound of the present invention is shown in the following general formula:

[0013]

[0014] Furthermore, in formulas I-A to I-L, R1 in each structural formula is independently selected from alkyl groups or alkoxy groups with carbon atoms 1-10.

[0015] The olefin-containing bis(diphenylacetylene) liquid crystal compound of this invention achieves surprising results compared to similar liquid crystal compounds disclosed in the prior art: (1) significantly improved liquid crystal phase transition temperature characteristics, such as a wide nematic liquid crystal temperature range, low melting point, and high-brightness characteristics; (2) higher birefringence; (3) lower rotational viscosity; and (4) higher dielectric tunability at high frequencies. These advantages are highly beneficial for microwave antennas, liquid crystal optical devices, etc.

[0016] The present invention also provides a liquid crystal composition. The provided liquid crystal composition comprises one or more liquid crystal compounds selected from those represented by general formula I. Specifically, the content of the compound in the liquid crystal composition is 1-50% by mass, with a weight percentage of 100%. Preferably, it is 10-40%, more preferably 15-30% of the compound of formula I.

[0017] The liquid crystal composition of the present invention further preferably contains one or more liquid crystal compounds selected from those represented by general structural formulas I-A to I-L.

[0018] In a further embodiment, the liquid crystal compound contains 0-90%, preferably 5-80%, and particularly preferably 10-70% of a compound of general formula II, based on the total amount of the mixture.

[0019] Where R1 represents an alkyl group with 1 to 10 carbon atoms, an alkoxy group with 1 to 10 carbon atoms, an alkylthio group with 1 to 10 carbon atoms, an alkenyl group with 2 to 10 carbon atoms, or an alkenoxy group with 2 to 10 carbon atoms; rings A, B, and C are independently represented as a benzene ring, cyclohexane, and cyclohexene, respectively, wherein the hydrogen atoms on the benzene ring can be replaced by fluorine, chlorine, methyl, or ethyl; Y represents H, F, Cl, CN, NCS, CF3, OCF2H, OCF3, or a group with 1 to 10 carbon atoms. Alkyl groups, alkoxy groups with 1 to 10 carbon atoms, alkenyl groups with 2 to 10 carbon atoms, or alkenyloxy groups with 2 to 10 carbon atoms; Z1 and Z2 are each independently represented as single bonds, -C≡C-, -CH=CH-, -CF=CF-; n=0, 1; and excluding when n=1, Z1 and Z2 are both represented as -C≡C-, ring A, ring B, and ring C are all represented as benzene rings, and R1 is an alkenyl group with 4 to 9 carbon atoms (that is, when n=1, the compound of general formula II is different from that of formula I).

[0020] The liquid crystal composition according to the present invention may further contain 0.001 to 1% additives, such as hindered phenolic antioxidants, hindered amine light stabilizers, etc. The hindered phenolic antioxidants are preferably derived from the following structures:

[0021] Where R' is an alkyl group having 1 to 9 carbon atoms or an alkoxy group having 1 to 9 carbon atoms.

[0022] The hindered amine light stabilizer is preferably derived from the following structure:

[0023] The amount of hindered phenolic antioxidant and amine light stabilizer added in the liquid crystal composition of the present invention is 0.001-1%, preferably 0.01%-0.5%, and more preferably 0.02%-0.2%.

[0024] The liquid crystal composition of the present invention may further contain one or more chiral additives. Their content may be 0.01% to 1%; preferably 0.1% to 0.5%. The chiral additive is preferably derived from the following structure:

[0025] Where R″ is an alkyl group having 1 to 9 carbon atoms or an alkoxy group having 1 to 9 carbon atoms.

[0026] In a specific embodiment, the liquid crystal composition of the present invention comprises a variety of compounds, preferably 3 to 20 compounds, more preferably 5 to 18, and even more preferably 7 to 15 compounds. These compounds can be mixed in a conventional manner: the various compounds are weighed according to a predetermined mass ratio, heated, and homogenized using stirring methods such as magnetic stirring or ultrasonic stirring until all components are completely dissolved; then filtered to obtain the final product. The liquid crystal composition can also be prepared by other conventional methods, such as using so-called premixes or so-called "multi-bottle" systems, where the components are themselves ready-to-use mixtures.

[0027] The performance of the liquid crystal composition of this invention at high frequencies was tested using a method reported in the literature: Penirschke, A. (2004). Cavity perturbation method for characterization of liquid crystals up to 35 GHz. Microwave Conference, 2004. 34th European Specifically, liquid crystal is introduced into a polytetrafluoroethylene (PTFE) or fused silica capillary, and the filled capillary is introduced into the center of a chamber with a resonant frequency of 19 GHz. An input signal source is then applied, and the output signal is recorded using a vector network analyzer. The changes in the resonant frequency and Q-factor between the liquid crystal-filled capillary and the blank capillary are measured, and the dielectric constant and loss tangent are calculated. The dielectric constant components perpendicular to and parallel to the liquid crystal director are obtained by aligning the liquid crystal in a magnetic field, with the direction of the magnetic field set accordingly and subsequently rotated by 90°.

[0028] Testing revealed that the preferred liquid crystal composition of this invention has a tuning rate τ ≥ 0.24, more preferably ≥ 0.26; the preferred liquid crystal material has a vertical dielectric loss tanδ. ⊥ ≤0.012, more preferably tanδ ⊥≤0.010; material quality factor η≥20, preferably η≥30. The preferred nematic phase temperature range of the liquid crystal composition of the present invention is 0~50℃ or a larger temperature range, more preferably -10~70℃ or a wider temperature range.

[0029] The liquid crystal compositions according to the present invention are well-suited for fabricating microwave components, such as phase shifters that can be tuned by an applied magnetic or electric field. These phase shifters can operate in the UHF band (0.3-1 GHz), L band (1-2 GHz), S band (2-4 GHz), C band (4-8 GHz), X band (8-12 GHz), Ku band (12-18 GHz), K band (18-27 GHz), Ka band (27-40 GHz), V band (50-75 GHz), W band (75-110 GHz), and up to 1 THz. The construction of the phase shifters according to this application is known to those skilled in the art. Typically, loaded line phase shifters, inverted microstrip line phase shifters, finline phase shifters, and preferably antipodal finline phase shifters, slotted phase shifters, microstrip line phase shifters, or coplanar waveguide (CPW) phase shifters are used. These components enable reconfigurable antenna arrays.

[0030] The liquid crystal composition of the present invention has a high birefringence (Δn). Preferably, the liquid crystal composition of the present invention has Δn ≥ 0.30 at 25°C and 589 nm, more preferably Δn ≥ 0.35.

[0031] The liquid crystal composition of the present invention, due to its high birefringence and low viscosity, is suitable for manufacturing liquid crystal optical elements, including phase modulation devices, gratings, wavelength selective switches (WSS), etc.

[0032] The technical advancements achieved by this invention due to the adoption of the above technical solutions are as follows: The liquid crystal compounds of this invention possess advantages such as a wide nematic liquid crystal phase, high birefringence, low viscosity, and high dielectric tunability. Compositions based on the liquid crystal compounds of this invention achieve high dielectric tunability and extremely low dielectric loss at high frequencies; and also possess advantages such as high optical birefringence, low viscosity, and a wide operating temperature range. Detailed Implementation

[0033] Unless otherwise specified, the scientific and technical terms and methods used in this article are based on the understanding of those skilled in the art or implemented using existing methods.

[0034] The present invention will be further described in detail below with reference to specific embodiments.

[0035] It should be noted that the detailed testing methods for the physical and photoelectric properties involved in this invention are as follows: (1) Liquid crystal phase transition temperature: Differential scanning calorimetry (DSC) was used: under a nitrogen atmosphere, the heating (cooling) rate was set to 5℃ / min.

[0036] Polarizing hot stage method: The liquid crystal sample is placed in an orthogonal polarizing microscopic hot stage, and the heating rate is set to 2℃ / min. The texture image of the liquid crystal phase transition is observed in a polarizing microscope to determine the liquid crystal phase state.

[0037] (2) Birefringence (Δn): The liquid crystal monomers were added to the basic formulation HOST at a mass ratio of 15:85% and heated to mix evenly. Using an Abbe refractometer, under constant temperature of 25℃ and a light source of 589nm, the birefringence (Δn) was measured for ordinary light. o ) and unusual light (n e The birefringence is obtained by extrapolating the refractive index of ( ).

[0038] (3) Dielectric constant (Δε, 1KHz): The liquid crystal monomers were added to the basic formula HOST at a mass ratio of 15:85%, heated and mixed evenly, and tested with an LCR meter under constant temperature of 25℃; Δε=ε ∥ -ε ⊥ That is, the dielectric constant along the long axis of the molecule (ε) ∥ ) and the dielectric constant along the short axis of the molecule (ε) ⊥ The difference between the two values ​​is used to extrapolate the dielectric anisotropy value Δε.

[0039] (4) Rotational viscosity (γ1): The liquid crystal monomers were added to the basic formulation HOST at a mass ratio of 15:85% and heated to mix evenly. Under constant temperature of 25℃, the transient current value Ip of the liquid crystal molecules deflecting with the electric field was measured by applying voltage to the liquid crystal test cell, and the rotational viscosity γ1 was calculated and extrapolated.

[0040] (5) Dielectric constant and dielectric loss (Δε, tanδ, 19GHz): Liquid crystal monomers were added to the basic formulation M0 at a mass ratio of 15:85%, heated and mixed uniformly, and then filled into polytetrafluoroethylene (PTFE) or fused silica capillaries under constant temperature of 25°C. The capillaries filled with liquid crystals were then inserted into the middle of the resonant cavity. An input signal source was then applied, and the output signal was recorded using a vector network analyzer. The changes in the resonant frequency and Q factor between the liquid crystal-filled capillary and the blank capillary were measured, and the dielectric constant and loss tangent were calculated. The dielectric constant components perpendicular to and parallel to the liquid crystal director were obtained by the orientation of the liquid crystal in the magnetic field. The direction of the magnetic field was set accordingly, and then rotated by 90° accordingly.

[0041] (6) Elastic constant (K) 11 K 33 Under constant temperature conditions of 25℃, K was obtained by fitting the capacitance-voltage (CV) curve of the liquid crystal. 11 and K 33 .

[0042] (7) Tuning frequency (τ): The tuning frequency was adopted from the literature Penirschke, A. (2004). Cavity perturbation method for characterization of liquid crystals up to 35 GHz. Microwave Conference, 2004. 34th European The relevant methods are disclosed in the document.

[0043] The basic formulation HOST described in the following examples is obtained by uniformly mixing the following three monomeric liquid crystals in a mass ratio of 1:1:1: .

[0044] Explanation of the codes used in this article: Table 1 Physical Parameters

[0045] Liquid crystal phase transition temperature: C represents melting point, S represents smectic phase, N represents nematic phase, and I represents liquid state.

[0046] Table 2 Structural Abbreviations

[0047] Table 3 Examples of Abbreviations

[0048] The synthesis of the liquid crystal compound represented by formula I of this invention can be based on existing related synthetic methods, by selecting appropriate raw materials. The synthetic route can refer to the synthetic route of the compound in Example 1 below; different target products can be obtained by substituting the corresponding reactants. All components involved in the following examples, except for the liquid crystal compound represented by formula I, can be obtained using existing disclosed methods or purchased from commercially available products.

[0049] Example 1: This example describes the synthesis of 4-((4-(but-3-enyl)phenyl)ethynyl)-2-ethyl-1-((4-isothiocyanate-phenyl)ethynyl)benzene V2PTP(E-2)TPS, with the following structural formula:

[0050] The synthetic route is shown below:

[0051] The specific method is as follows: (1) Under nitrogen protection, 15.6 g of 2-ethyl-4-bromo-1-iodobenzene, 100 mL of triethylamine, 0.35 g of palladium chloride ditriphenylphosphine, 0.29 g of cuprous iodide, and 0.39 g of triphenylphosphine were added to the reactor. At room temperature, 30 mL of triethylamine solution containing 7.4 g of trimethylsilylacetylene was added dropwise. After the addition was complete, the reaction was carried out at room temperature for 4 h. The temperature was raised to 50 °C, and 30 mL of triethylamine solution containing 7.8 g of 4-(but-3-enyl)phenylacetylene was added dropwise. After the addition was complete, the reaction was continued for 4 h. The mixture was filtered, the filtrate was concentrated to dryness, 100 mL of toluene was added, the mixture was washed with water, dried, and the toluene was removed under reduced pressure. The product was passed through a silica gel column, eluted with n-heptane, and concentrated to obtain 15.3 g of an oily liquid. (2) Add 15.3g of liquid obtained in step (1) and 200mL of ethanol to a new reaction vessel, add 1.5g of potassium carbonate, stir and react at room temperature for 5h; remove ethanol by vacuum distillation, add 100mL of toluene for extraction, wash the organic layer with water until neutral, remove the solvent by vacuum, and obtain 11.0g of oily liquid 4-((4-(but-3-enyl)phenyl)ethynyl)-2-ethyl-1-ethynylbenzene; (3) Under nitrogen protection, 4.4 g of p-iodoaniline, 0.14 g of palladium chloride di-triphenylphosphine, 0.12 g of cuprous iodide, and 0.16 g of triphenylphosphine were added to another reactor. The temperature was raised to 50 °C, and 60 mL of a triethylamine solution containing 5.7 g of 4-((4-(but-3-enyl)phenyl)ethynyl)-2-ethyl-1-ethynylbenzene was slowly added dropwise. After the addition was complete, the reaction was kept at the temperature for 4 h. The mixture was cooled to room temperature, filtered, and the filtrate was concentrated to dryness. 100 mL of toluene was added, the mixture was washed with water, dried, and the toluene was removed under reduced pressure. The mixture was recrystallized from toluene to obtain 5.6 g of brown solid 4-((4-((4-(but-3-enyl)phenyl)ethynyl)-2-ethylphenyl)ethynyl)aniline. (4) Dissolve the product obtained in step (3) in 60 mL of tetrahydrofuran, add 2.6 g of sulfur phosgene dropwise at room temperature, and stir for 4 h. Concentrate the reaction solution, extract with toluene, wash with water until neutral, remove toluene under reduced pressure, pass the product through a silica gel column, elute with n-heptane, concentrate the eluent under reduced pressure to dryness, and recrystallize repeatedly with n-heptane to obtain 4.7 g of white solid 4-((4-(but-3-enyl)phenyl)ethynyl)-2-ethyl-1-((4-isothiocyanate-phenyl)ethynyl)benzene.

[0052] The product structure identification data are as follows: 1H NMR(500 MHz, CDCl3) δ (ppm): 1.309(t, 3H, J=7.5Hz), 2.355~2.399(m,2H), 2.724(t, 2H, J=7.5Hz), 2.862 (q, 2H, J=7.5Hz), 4.976~5.061(m, 2H), 5.801~5.882(m, 1H), 7.166~7.208 (m, 4H), 7.323~7.342(m, 1H), 7.411~ 7.497(m, 6H). 13 C NMR(125 MHz, CDCl3) δ (ppm): 14.6, 27.6, 35.3, 88.9, 90.0, 91.3,93.3, 115.2, 120.5, 121.7, 122.5, 123.8, 126.9(2C), 128.6(2C), 128.9, 131.0,131.1, 131.6(2C), 132.1, 132.7(2C), 136.7, 137.7, 142.6, 146.3. MS m / z (RI, %): 417.1 (M + , 51), 376.1(100).

[0053] DSC: C 79.0 N 172.4 I.

[0054] When this compound was added to the base formulation HOST at a mass percentage of 15%, no crystallization occurred during storage at room temperature, indicating that the compound has good compatibility.

[0055] Further testing revealed that the compound has the following birefringence: Δn = 0.578, γ1 = 641.4 mPa·s, and Δε (1 kHz) = 7.9.

[0056] Example 2: This embodiment is 4-((4-(but-3-enyl)phenyl)ethynyl)-1-((4-ethylphenyl)ethynyl)-2-methylbenzene, with the following structural formula:

[0057] The synthesis route is shown below:

[0058] The specific method is as follows: (1) Under nitrogen protection, 29.7 g of 2-methyl-4-bromoiodobenzene, 100 mL of triethylamine, 0.70 g of palladium chloride ditriphenylphosphine, 0.57 g of cuprous iodide, and 0.79 g of triphenylphosphine were added to the reactor. 50 mL of triethylamine solution containing 13.0 g of 4-ethylphenylacetylene was slowly added dropwise. After the addition was complete, the mixture was stirred at room temperature for 4 h. The mixture was filtered, the filtrate was concentrated to dryness, 200 mL of toluene was added, the mixture was washed with water, dried, the toluene was removed under reduced pressure, and ethanol was added for recrystallization to obtain 26.9 g of white solid 4-bromo-1-((4-ethylphenyl)acetylene)-2-methylbenzene. (2) Under nitrogen protection, 26.9 g of 4-bromo-1-((4-ethylphenyl)ethynyl)-2-methylbenzene, 100 mL of triethylamine, 0.63 g of palladium chloride ditriphenylphosphine, 0.51 g of cuprous iodide, and 0.71 g of triphenylphosphine were added to another reactor. The temperature was raised to 60 °C, and 50 mL of triethylamine solution containing 14.0 g of 4-(but-3-enyl)phenylacetylene was slowly added dropwise. After the addition was complete, the mixture was kept warm and stirred for 4 h. The mixture was cooled to room temperature, filtered, and the filtrate was concentrated to dryness. 200 mL of toluene was added, the mixture was washed with water, dried, and the toluene was removed under reduced pressure. The product was passed through a silica gel column and eluted with n-heptane. The product was recrystallized twice with n-heptane to obtain 25.6 g of white solid 4-((4-(but-3-enyl)phenyl)ethynyl)-1-((4-ethylphenyl)ethynyl)-2-methylbenzene.

[0059] The structural assessment data is as follows: 1 H NMR(500 MHz, CDCl3) δ (ppm): 1.243 (t, 3H, J=7.5Hz), 2.354~2.395(m,2H), 2.497(s, 3H), 2.642~2.734(m, 4H), 4.974~5.052 (m, 2H), 5.800~5.880(m,1H), 7.185~7.193(m, 4H, J=8Hz), 7.244~7.462(m, 7H). 13 C NMR(125 MHz, CDCl3) δ (ppm): 15.4, 20.6, 28.9, 35.2, 35.3, 87.5,88.9, 90.9, 95.3, 115.2, 120.5, 120.6, 123.0, 123.2, 128.0(2C), 128.6(2C),128.8, 131.5(2C), 131.6(2C), 131.7, 132.4, 137.7, 140.1, 142.4, 144.9. MS m / z (RI, %): 374.1 (M + , 52), 333.0(100).

[0060] DSC: C96.0 N 199.6 I.

[0061] When this compound was added to the base formulation at a mass percentage of 15%, no crystallization occurred during storage at room temperature, indicating that the compound has good compatibility. Further testing yielded the following physical property parameters for the compound: Δn = 0.4714, γ1 = 392 mPa·s, Δε(1kHz) = 1.8.

[0062] Example 3: This embodiment is 4-((4-(but-3-enyl)phenyl)ethynyl)-2-chloro-1-((4-ethylphenyl)ethynyl)benzene, with the following structural formula:

[0063] By replacing 4-bromo-2-chloroiodobenzene in Example 2 with 4-bromo-2-methyliodobenzene, and performing the same synthesis method as in Example 2, 4-((4-(but-3-enyl)phenyl)ethynyl)-2-chloro-1-((4-ethylphenyl)ethynyl)benzene was obtained.

[0064] The structural assessment data is as follows: 1 H NMR(500 MHz, CDCl3) δ (ppm):1.243 (t, 3H, J=7.5Hz), 2.353~2.397(m,2H), 2.667(q, 2H, J=7.5Hz), 2.724(t, 2H, J=7.5Hz), 4.976 (m, 2H), 5.797~5.878(m, 1H), 7.185(t, 4H, J=8Hz), 7.350~7.369(m, 1H), 7.432~ 7.578(m, 6H). 13 C NMR(125 MHz, CDCl3) δ (ppm): 15.4, 28.9, 35.2, 35.3, 85.6, 87.5,92.4, 96.5, 115.3, 119.9, 120.1, 123.1, 124.4, 128.0(2C), 128.6(2C), 129.5,131.7(2C), 131.8(2C), 132.0, 132.8, 135.7, 137.7, 142.9, 145.4. MS m / z (RI, %): 394.1 (M + , 46), 396.1(M+2, 16), 353.1(100), 355.1(37.5).

[0065] DSC: C 89.2 N 190.1 I.

[0066] When this compound was added to the base formulation at a mass percentage of 15%, no crystallization occurred during storage at room temperature, indicating that the compound has good compatibility. Further testing yielded the following physical property parameters for the compound: Δn = 0.4634, γ1 = 362 mPa·s, Δε(1kHz) = 1.2.

[0067] Example 4: This embodiment is a liquid crystal composition N0, and its mass ratio and performance parameters are shown in Table 4 below: Table 4

[0068] The monomeric liquid crystal V2PTP(E-2)TPS was added to NO at a mass percentage of 10%, heated and mixed evenly, and the dielectric performance parameters at 19 GHz were tested. The results are shown in Table 5.

[0069] Table 5

[0070] It can be seen that when 10% monomeric liquid crystal V2PTP(E-2)TPS is added to the composition of N0, the dielectric constant is significantly increased, the dielectric loss is reduced, and the quality factor is greatly improved compared with N0.

[0071] Example 5: The liquid crystal composition of this embodiment has the following mass ratio and performance parameters: Table 6 below: Table 6

[0072] This liquid crystal composition has a high birefringence and a low rotational viscosity, making it suitable for fabricating liquid crystal optical elements, including phase modulation devices, gratings, wavelength selective switches (WSS), etc.

[0073] Example 6: The liquid crystal composition of this embodiment has the following mass ratio and performance parameters: Table 7 below. Table 7

[0074] This liquid crystal composition has an extremely high birefringence; it also has a very high dielectric constant at a high frequency of 19 GHz, low dielectric loss, and a large quality factor.

[0075] Comparative Example 1: The structural formula of 4PTP(E-2)TPS, a bis(diphenylacetylene) liquid crystal compound with n-butyl terminal groups, is shown below:

[0076] The liquid crystal phase transition temperature of this compound, as determined by DSC, is: C 79.2 N 158.1 I.

[0077] The compound was added to the base formulation Host at a ratio of 15%, and its birefringence was tested to be 0.567, γ1 = 658 mPa·s.

[0078] Compared with Comparative Example 1, the liquid crystal compound of Example 1 of this invention, after replacing n-butyl with 3-butenyl, has an increased clearing point of 14.3°C, an increased nematic phase temperature range of 14.5°C, an increased birefringence of 0.011, and a decreased rotational viscosity of 16.6 mPa·s.

[0079] 4PTP(E-2)TPS was added to the liquid crystal composition N0 at a mass percentage of 10%, and the dielectric properties were tested at 19 GHz. The results are shown in Table 8.

[0080] Table 8

[0081] Compared with Comparative Example 1, in Example 4, the butenyl bis(diphenylacetylene)V2PTP(E-2)TPNCS liquid crystal compound of the present invention has a larger dielectric constant Δε at the same addition ratio of 10%.

[0082] Comparative Example 2: The structural formula of a bis(diphenylacetylene) liquid crystal compound with a n-butyl terminal group is shown below:

[0083] The liquid crystal phase transition temperature of this compound, as determined by DSC, is: C 76.6 N 186.4 I.

[0084] The compound was added to the base formulation Host at a ratio of 15%, and its birefringence was tested to be Δn=0.4567 and γ1=410.7mPa·s.

[0085] Compared with Comparative Example 2, the liquid crystal compound of Example 2 of this invention, after replacing n-butyl with 3-butenyl, showed an increase of 13.2°C in clearing point; an increase of 0.0147 in birefringence; and a decrease of 18.7 mPa·s in rotational viscosity.

[0086] Comparative Example 3: The structural formula of a bis(diphenylacetylene) liquid crystal compound with a n-butyl terminal group is shown below:

[0087] The liquid crystal phase transition temperature of this compound, as determined by DSC, is: C 90.5 N 175.1 I.

[0088] The compound was added to the base formulation Host at a ratio of 15%, and its birefringence Δn = 0.444 and γ1 = 375.3 mPa·s were tested.

[0089] Compared with Comparative Example 3, the liquid crystal compound of Example 3 of this invention, after replacing n-butyl with 3-butenyl, showed an increase of 15.0°C in clearing point; an increase of 0.0194 in birefringence; and a decrease of 13.3 mPa·s in rotational viscosity.

Claims

1. A bis(diphenylacetylene) liquid crystal compound containing an olefin chain, characterized in that, The structure of the compound is shown in general formulas I-G to I-L: In formulas I-G to I-L, R is hydrogen; R1 in each structural formula is independently selected from alkyl groups with 1-4 carbon atoms.

2. A liquid crystal composition, characterized in that, The liquid crystal composition contains one or more liquid crystal compounds selected from those represented by general structural formulas I-G to I-L.

3. The liquid crystal composition according to claim 2, characterized in that, Based on a mass percentage of 100%, the liquid crystal compound represented by the general structural formula I-G to I-L has a mass percentage content of 1%-50% in the liquid crystal composition.

4. The liquid crystal composition according to claim 2, characterized in that, The liquid crystal composition contains one or more Selected from compounds represented by general formula II: In formula II, R1 is an alkyl group with 1 to 10 carbon atoms, an alkoxy group with 1 to 10 carbon atoms, an alkylthio group with 1 to 10 carbon atoms, an alkenyl group with 2 to 10 carbon atoms, or an alkenoxy group with 2 to 10 carbon atoms; Ring A, ring B, and ring C are each independently selected from benzene rings, cyclohexane, cyclohexene, or benzene rings in which hydrogen atoms are substituted by fluorine, chlorine, methyl, or ethyl. Y is H, F, Cl, CN, NCS, CF3, OCF2H, OCF3, alkyl with 1 to 10 carbon atoms, alkoxy with 1 to 10 carbon atoms, alkenyl with 2 to 10 carbon atoms, or alkenoxy with 2 to 10 carbon atoms; Z1 and Z2 are each independently selected from single bonds, -C≡C-, -CH=CH-, or -CF=CF-; n=0, 1; and excluding when n=1, Z1 and Z2 are both selected from -C≡C-, ring A, ring B and ring C are all selected from benzene rings, and R1 is an alkenyl group with 4 to 9 carbon atoms.

5. The liquid crystal composition according to claim 4, characterized in that, Based on a mass percentage of 100%, the compound represented by general formula II has a mass percentage content of greater than 0 and less than or equal to 90% in the liquid crystal composition.

6. The liquid crystal composition according to claim 2, characterized in that, The liquid crystal composition also contains one or more of hindered phenolic antioxidants and hindered amine light stabilizers.

7. The liquid crystal composition according to claim 2, characterized in that, The liquid crystal composition also contains chiral additives.

8. A liquid crystal high-frequency component, characterized in that, The raw materials for preparing the liquid crystal high-frequency component include any liquid crystal compound as described in claim 1, or any liquid crystal composition as described in any of claims 2-7.

9. A liquid crystal optical element, characterized in that, The raw materials for preparing the liquid crystal optical element include any liquid crystal compound as described in claim 1, or any liquid crystal composition as described in any of claims 2-7.

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