Compounds, preparation method therefor, and use thereof

Abstract

Compounds, a preparation method therefor, and the use thereof, belonging to the field of organic materials. Each of the compound comprises a first chain hydrocarbyl group, a first phenyl group, a second phenyl group, a thieno[3,2-b]thienyl group, and a second chain hydrocarbyl group. The first chain hydrocarbyl group is linked to a carbon atom of the first phenyl group, another carbon atom of the first phenyl group is linked to a carbon atom of the second phenyl group by means of a first linking bond, another carbon atom of the second phenyl group is linked to a carbon atom of the thieno[3,2-b]thienyl group by means of a second linking group, and another carbon atom of the thieno[3,2-b]thienyl group is linked to the second chain hydrocarbyl group. The first phenyl group has one or two first substituents which are F, -CF3 or -OCF3. The first and second chain hydrocarbyl groups are straight-chain alkyl groups, alkoxyl groups, fluoroalkyl groups, alkenyl groups, alkenyloxy groups, or difluorovinyl groups. The compounds can be used as liquid crystal monomers and can improve the birefringence, low-temperature stability, high-temperature stability and the nematic phase temperature range of liquid crystal materials.

Description

Compound, preparation method and application thereof

[0001] This application claims priority to Chinese patent application No. 202311424905.7, filed on October 30, 2023, entitled “Compounds, Preparation Methods and Applications Thereof,” the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present disclosure relates to the field of organic materials, and in particular to compounds, preparation methods, and applications thereof. Background Art

[0003] Liquid crystal materials are usually formed by combining and compounding a variety of liquid crystal monomers, so that the liquid crystal materials have at least the following properties: high birefringence, a wide nematic phase temperature range, strong temperature resistance (low temperature stability and high temperature stability), excellent UV resistance, etc.

[0004] However, some currently known high-birefringence liquid crystal materials, despite their high birefringence, have weak UV resistance and poor high-temperature stability, or their nematic phase temperature range is narrow (-10°C-110°C), resulting in poor low-temperature stability.

[0005] Public content

[0006] In view of this, the present disclosure provides compounds and their preparation methods and applications, which can solve the technical problems in related technologies. Specifically, the following technical solutions are included:

[0007] In one aspect, a compound is provided, comprising a first chain hydrocarbon group, a first phenyl group, a second phenyl group, a thieno[3,2-b]thienyl group, and a second chain hydrocarbon group;

[0008] The first chain hydrocarbon group is connected to one carbon atom of the first phenyl group, another carbon atom of the first phenyl group is connected to one carbon atom of the second phenyl group via a first connecting bond, another carbon atom of the second phenyl group is connected to one carbon atom of the thieno[3,2-b]thienyl group via a second connecting group, and another carbon atom of the thieno[3,2-b]thienyl group is connected to the second chain hydrocarbon group;

[0009] The first phenyl group has one or two first substituents, the first substituents are adjacent to the carbon atom connected to the first connecting bond in the first phenyl group, and the first substituents are F, -CF3 or -OCF3;

[0010] The first chain hydrocarbon group and the second chain hydrocarbon group are selected from a straight chain alkyl group, a straight chain alkoxy group, a straight chain fluoroalkyl group, a straight chain alkenyl group, a straight chain alkenyloxy group or a difluorovinyl group.

[0011] The compound provided by the embodiment of the present disclosure is composed of a first chain hydrocarbon group, a first phenyl group, a second phenyl group, a thieno[3,2-b]thienyl group and a second chain hydrocarbon group connected in sequence, so that the compound can be used as a liquid crystal monomer, and the above-mentioned various groups act synergistically so that the compound has both high birefringence and strong low-temperature stability. In addition, by introducing a thieno[3,2-b]thienyl group therein, it is beneficial to further improve the birefringence of the compound. The first phenyl group has one or two first substituents. By making the first substituent F, -CF3 or -OCF3, the ordered arrangement and molecular interaction between the compound molecules can be effectively reduced, which is beneficial to improving the low-temperature stability of the compound. When the compound provided by the embodiment of the present disclosure is used as a liquid crystal monomer for preparing a liquid crystal material, the birefringence, low-temperature stability and high-temperature stability of the high-birefringence liquid crystal material can be improved, which is also beneficial to broaden the nematic phase temperature range of the liquid crystal material.

[0012] In some possible implementations, the first chain hydrocarbon group and the second chain hydrocarbon group are each independently selected from a straight-chain alkyl group with a carbon number of 1-9, a straight-chain alkoxy group with a carbon number of 1-9, a straight-chain fluoroalkyl group with a carbon number of 1-9, a straight-chain alkenyl group with a carbon number of 2-9, a straight-chain alkenyloxy group with a carbon number of 2-9, or a difluorovinyl group with a carbon number of 2-9.

[0013] In some possible implementations, the second phenyl groups are substituted or unsubstituted;

[0014] The substituted second phenyl group has one or more second substituents, and the second substituents are selected from -F, -CH3, -CH2CH3, -OCF3, cyclopropyl, cyclobutyl or cyclohexyl.

[0015] By selecting the second substituent from the above types, the melting point of the compound is lowered. When the compound provided in the embodiment of the present disclosure is used as a liquid crystal monomer to prepare a liquid crystal material, the low-temperature stability of the high birefringence liquid crystal material is further improved.

[0016] In some possible implementations, the first connecting bond and the second connecting bond are each independently selected from a carbon-carbon single bond, a carbon-carbon double bond, an alkynyl bond, an ester bond or a difluoromethyl ether bridge bond, and the above connecting bonds are applicable to increasing the birefringence of the compound and lowering its crystallization point.

[0017] In some implementations, the chemical structure of the compound is as follows:

[0018] wherein R1 and R2 represent a first chain hydrocarbon group and a second chain hydrocarbon group, respectively, and both are independently selected from a straight-chain alkyl group having 1 to 9 carbon atoms, a straight-chain alkoxy group having 1 to 9 carbon atoms, a straight-chain fluoroalkyl group having 1 to 9 carbon atoms, a straight-chain alkenyl group having 2 to 9 carbon atoms, a straight-chain alkenyloxy group having 2 to 9 carbon atoms, or a difluorovinyl group having 2 to 9 carbon atoms;

[0019] Z1 and Z2 represent the first connecting bond and the second connecting bond, respectively, and are each independently selected from a carbon-carbon single bond, a carbon-carbon double bond, an alkynyl group, an ester group or a difluoromethyl ether bridge bond;

[0020] X1, and X4-X6 are each independently selected from -H, -F, -CH3, -CH2CH3, -OCF3, cyclopropyl, cyclobutyl or cyclohexyl;

[0021] At least one of X2 and X3 is F, -CF3 or -OCF3.

[0022] Compounds with this type of chemical structure can be used as liquid crystal monomers. When used to prepare liquid crystal materials, they can at least improve the birefringence and low-temperature stability of high-birefringence liquid crystal materials, and at the same time help broaden the nematic phase temperature range of liquid crystal materials.

[0023] Illustratively, the compound is compound I-1, compound I-2, compound I-3 or compound I-4;

[0024] The chemical structural formula I-1 corresponding to the compound I-1, the chemical structural formula I-2 corresponding to the compound I-2, the chemical structural formula I-3 corresponding to the compound I-3, and the chemical structural formula I-4 corresponding to the compound I-4 are shown below:

[0025] Wherein, R1 and R2 are each independently selected from a straight-chain alkyl group having 1 to 9 carbon atoms or a straight-chain alkoxy group having 1 to 9 carbon atoms.

[0026] On the other hand, embodiments of the present disclosure provide use of any of the above compounds in liquid crystal materials.

[0027] The compound provided in the embodiments of the present disclosure can be used as a liquid crystal monomer. The compound can also be used in combination with other types of liquid crystal monomers to achieve the purpose of optimizing the following effects of the liquid crystal material: higher birefringence, wider nematic phase temperature, excellent low-temperature stability, excellent high-temperature stability, and excellent UV resistance.

[0028] In another aspect, the present disclosure provides a method for preparing any one of the above compounds, the method comprising:

[0029] Determining a plurality of monomers for synthesizing the compound based on the chemical structure of the compound;

[0030] The compound is prepared by gradually reacting multiple monomers;

[0031] The reaction includes at least one of a Sonogashira coupling reaction, a Suzuki coupling reaction, and a halogenation reaction.

[0032] The disclosed embodiments determine the multiple monomers used to synthesize the compound based on the chemical structure of the compound. For example, the number of monomers used to synthesize the compound is at least 4. First, two of the monomers are reacted to form a first intermediate. Then, the first intermediate is reacted with another monomer to form a second intermediate, and so on, thereby using multiple monomers through multi-step reactions to ultimately prepare the compound.

[0033] In another aspect, embodiments of the present disclosure provide a liquid crystal material comprising a first liquid crystal monomer and a second liquid crystal monomer, wherein the first liquid crystal monomer is any of the compounds described above. The second liquid crystal monomer is configured such that, at a temperature of 0°C or less, crystallization does not occur after the second liquid crystal monomer is mixed with the first liquid crystal monomer.

[0034] The liquid crystal material provided by the embodiments of the present disclosure utilizes any of the aforementioned compounds provided by the embodiments of the present disclosure as a liquid crystal monomer, resulting in at least a high birefringence, a wide nematic phase temperature, and excellent low-temperature stability. By combining the first liquid crystal monomer with the aforementioned second liquid crystal monomer, their synergistic effect results in the prepared liquid crystal material having the advantages of a high birefringence, a wide nematic phase temperature, excellent low-temperature stability, and excellent high-temperature stability.

[0035] In some possible implementations, the second liquid crystal monomer is selected from at least one of compound II-1, compound II-2, compound II-3, compound II-4, compound II-5, compound II-6, compound II-7, and compound II-8;

[0036] The chemical structural formula II-1 corresponding to the compound II-1, the chemical structural formula II-2 corresponding to the compound II-2, the chemical structural formula II-3 corresponding to the compound II-3, the chemical structural formula II-4 corresponding to the compound II-4, the chemical structural formula II-5 corresponding to the compound II-5, the chemical structural formula II-6 corresponding to the compound II-6, the chemical structural formula II-7 corresponding to the compound II-7, and the chemical structural formula II-8 corresponding to the compound II-8 are shown below:

[0037] Among them, R3-R12 Each is independently selected from a straight-chain alkyl group having 1 to 6 carbon atoms and a straight-chain alkoxy group having 1 to 6 carbon atoms;

[0038] X7-X 31 Each is independently selected from -H, -F, -CH3, -CH2CH3 or -OCF3.

[0039] In some possible implementations, the liquid crystal material further includes an auxiliary agent, and the auxiliary agent is selected from at least one of a UV absorber, a UV stabilizer, and an antioxidant.

[0040] By adding one or more of the above-mentioned additives to the liquid crystal material, the ultraviolet resistance and high-temperature stability of the liquid crystal material can be further improved.

[0041] In some possible implementations, the liquid crystal material has at least one of the following characteristics: no crystallization at -60°C to 0°C; no color change at 0°C to 150°C; no change in temperature at a temperature less than or equal to 80 mW / cm 2 It does not change color under high UV intensity.

[0042] On the other hand, the embodiments of the present disclosure further provide an optoelectronic device, which includes a packaging structure and a liquid crystal material packaged inside the packaging structure. The liquid crystal material is any of the liquid crystal materials described above in the embodiments of the present disclosure.

[0043] Exemplarily, the optoelectronic device includes a wavelength selective switch, a microwave antenna or a display device. DETAILED DESCRIPTION

[0044] The following is a clear and complete description of the technical solutions in the embodiments of the present disclosure. Obviously, the embodiments described are only part of the embodiments of the present disclosure, not all of them. Based on the embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present disclosure.

[0045] Liquid crystal materials are widely used in the optoelectronic field, such as in laser projection, optoelectronic display, and optoelectronic communications. The above application scenarios require liquid crystal materials to have at least the following properties: high birefringence, a wide nematic phase temperature range, strong temperature resistance (low temperature stability and high temperature stability), excellent UV resistance, etc.

[0046] Among them, under the premise of keeping the amount of light phase modulation unchanged, the higher birefringence can reduce the thickness of the liquid crystal layer, so that the optoelectronic device can obtain a faster response speed and effectively avoid the edge field effect between device pixels, thereby improving the dimming efficiency. The wider the nematic phase temperature range of the liquid crystal material, the wider the operating temperature range of the optoelectronic device. If the nematic phase temperature range of the liquid crystal material is expected to be wide enough, for example, the crystallization point of the liquid crystal material is less than -20°C (further less than -40°C), and the clearing point of the liquid crystal material is greater than 120°C, it is necessary to make the mutual solubility of multiple liquid crystal monomers good. Strong UV resistance and temperature resistance (such as high temperature stability) make optoelectronic devices suitable for packaging conditions and outdoor environments.

[0047] However, currently known liquid crystal materials, despite their high birefringence, have weak UV resistance, poor high-temperature stability, or have a narrow nematic phase temperature range (-10° C. to 110° C.), resulting in poor low-temperature stability.

[0048] In response to the technical problems existing in the related art, the embodiments of the present disclosure provide a compound, which includes a first chain hydrocarbon group, a first phenyl group, a second phenyl group, a thieno[3,2-b]thienyl group and a second chain hydrocarbon group. The first chain hydrocarbon group is connected to one of the carbon atoms of the first phenyl group, another carbon atom of the first phenyl group is connected to one of the carbon atoms of the second phenyl group through a first connecting bond, another carbon atom of the second phenyl group is connected to one of the carbon atoms of the thieno[3,2-b]thienyl group through a second connecting group, and another carbon atom of the thieno[3,2-b]thienyl group is connected to the second chain hydrocarbon group. The first phenyl group has one or two first substituents, the first substituents are adjacent to the carbon atom connected to the first connecting bond in the first phenyl group, and the first substituents are F, -CF3 or -OCF3; the first chain hydrocarbon group and the second chain hydrocarbon group are selected from straight-chain alkyl, straight-chain alkoxy, straight-chain fluoroalkyl, straight-chain alkenyl, straight-chain alkenyloxy or difluorovinyl.

[0049] The compound provided by the embodiment of the present disclosure is composed of a first chain hydrocarbon group, a first phenyl group, a second phenyl group, a thieno[3,2-b]thienyl group and a second chain hydrocarbon group connected in sequence, so that the compound can be used as a liquid crystal monomer, and the above-mentioned various groups act synergistically so that the compound has both high birefringence and strong low-temperature stability. In addition, by introducing a thieno[3,2-b]thienyl group therein, it is beneficial to further improve the birefringence of the compound. The first phenyl group has one or two first substituents. By making the first substituent F, -CF3 or -OCF3, the ordered arrangement and molecular interaction between the compound molecules can be effectively reduced, which is beneficial to improving the low-temperature stability of the compound. When the compound provided by the embodiment of the present disclosure is used as a liquid crystal monomer for preparing a liquid crystal material, the birefringence, low-temperature stability and high-temperature stability of the high-birefringence liquid crystal material can be improved, which is also beneficial to broaden the nematic phase temperature range of the liquid crystal material.

[0050] The “high birefringence liquid crystal material” involved in the embodiments of the present disclosure refers to a liquid crystal material with a birefringence greater than 0.3.

[0051] In some examples, the first and second chain hydrocarbon groups are each independently selected from a linear alkyl group having 1 to 9 carbon atoms, a linear alkoxy group having 1 to 9 carbon atoms, a linear fluoroalkyl group having 1 to 9 carbon atoms, a linear alkenyl group having 2 to 9 carbon atoms, a linear alkenyloxy group having 2 to 9 carbon atoms, or a difluorovinyl group having 2 to 9 carbon atoms. The first and second chain hydrocarbon groups may be the same or different.

[0052] For example, the straight-chain alkyl group with 1-9 carbon atoms includes, but is not limited to, methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, etc. The number of alkoxy groups in the straight-chain alkoxy group with 1-9 carbon atoms can be one, two, or more. In the embodiment of the present disclosure, the chemical formula of the straight-chain alkoxy group can be -OC n H 2n+1 , which include but are not limited to: methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, octyloxy, etc. The number of fluorine elements in the straight-chain fluoroalkyl group can be one, two or more.

[0053] In the embodiments of the present disclosure, the second phenyl group is substituted or unsubstituted, and the substituted second phenyl group has one or more second substituents. The second phenyl group has four substitutable sites. In the embodiments of the present disclosure, the number of second substituents can be one, two, three, or four. For further example, the number of second substituents can be one, two, or three. When there are multiple second substituents, the multiple second substituents can be the same or different.

[0054] In some examples, the second substituent is selected from -F, -CH3, -CH2CH3, -OCF3, cyclopropyl, cyclobutyl, or cyclohexyl.

[0055] By selecting the second substituent from the above types, the melting point of the compound is lowered. When the compound provided in the embodiment of the present disclosure is used as a liquid crystal monomer to prepare a liquid crystal material, the low-temperature stability of the high birefringence liquid crystal material is further improved.

[0056] In the embodiment of the present disclosure, the first connecting bond and the second connecting bond are each independently selected from a carbon-carbon single bond, a carbon-carbon double bond, an alkynyl bond, an ester bond or a difluoromethyl ether bridge bond. The above connecting bonds are applicable to increasing the birefringence of the compound and lowering its crystallization point.

[0057] The first connecting bond and the second connecting bond may be the same or different. For example, the first connecting bond and the second connecting bond are both selected from carbon-carbon single bonds, or the first connecting bond and the second connecting bond are both selected from alkynyl bonds, or one of the first connecting bond and the second connecting bond is selected from a carbon-carbon single bond and the other is selected from an alkynyl bond.

[0058] In some possible implementations, the chemical structural formula of the compound involved above is as follows:

[0059] wherein R1 and R2 represent a first chain hydrocarbon group and a second chain hydrocarbon group, respectively, and both are independently selected from a straight-chain alkyl group having 1 to 9 carbon atoms, a straight-chain alkoxy group having 1 to 9 carbon atoms, a straight-chain fluoroalkyl group having 1 to 9 carbon atoms, a straight-chain alkenyl group having 2 to 9 carbon atoms, a straight-chain alkenyloxy group having 2 to 9 carbon atoms, or a difluorovinyl group having 2 to 9 carbon atoms.

[0060] Z1 and Z2 represent the first connecting bond and the second connecting bond, respectively, and are each independently selected from a carbon-carbon single bond, a carbon-carbon double bond, an alkynyl group, an ester group or a difluoromethyl ether bridge bond;

[0061] X1, and X4-X6 are each independently selected from -H, -F, -CH3, -CH2CH3, -OCF3, cyclopropyl, cyclobutyl or cyclohexyl;

[0062] At least one of X2 and X3 is F, -CF3 or -OCF3.

[0063] Compounds with this type of chemical structure can be used as liquid crystal monomers. When used to prepare liquid crystal materials, they can at least improve the birefringence, low-temperature stability and high-temperature stability of high-birefringence liquid crystal materials, and at the same time help broaden the nematic phase temperature range of liquid crystal materials.

[0064] Based on the above chemical formula, the compound may be compound I-1, compound I-2, compound I-3 or compound I-4, wherein the chemical formula I-1 corresponding to compound I-1, the chemical formula I-2 corresponding to compound I-2, the chemical formula I-3 corresponding to compound I-3, and the chemical formula I-4 corresponding to compound I-4 are shown below:

[0065] Wherein, R1 and R2 are each independently selected from a straight-chain alkyl group having 1 to 9 carbon atoms or a straight-chain alkoxy group having 1 to 9 carbon atoms.

[0066] Compound I-1, compound I-2, compound I-3, and compound I-4 have higher birefringence and stronger low-temperature stability. When the compound is used as a liquid crystal monomer in a liquid crystal material, one, any two, any three, or four of the above-mentioned compounds I-1, compound I-2, compound I-3, and compound I-4 can be used.

[0067] Furthermore, the compound used in the liquid crystal material may be one or more of the following compounds, wherein R1 and R2 are independently selected from a linear alkyl group or a linear alkoxy group having 1 to 9 carbon atoms.

[0068] One example is that the compound provided in the embodiments of the present disclosure is a liquid crystal monomer compound.

[0069] On the other hand, embodiments of the present disclosure also provide applications of any of the above compounds in liquid crystal materials.

[0070] The compound provided in the embodiments of the present disclosure can be used as a liquid crystal monomer. The compound can also be used in combination with other types of liquid crystal monomers to achieve the purpose of optimizing the following effects of the liquid crystal material: higher birefringence, wider nematic phase temperature, excellent low-temperature stability, excellent high-temperature stability, and excellent UV resistance.

[0071] In another aspect, the present disclosure also provides a method for preparing any of the aforementioned compounds, comprising: determining, based on the chemical structure of the compound, a plurality of monomers for synthesizing the compound; and gradually reacting the plurality of monomers to produce the compound. The types of reactions involved include, but are not limited to, at least one of a Sonogashira coupling reaction, a Suzuki coupling reaction, and a halogenation reaction.

[0072] The disclosed embodiments determine the multiple monomers used to synthesize the compound based on the chemical structure of the compound. For example, the number of monomers used to synthesize the compound is at least 4. First, two of the monomers are reacted to form a first intermediate. Then, the first intermediate is reacted with another monomer to form a second intermediate, and so on, thereby using multiple monomers through multi-step reactions to ultimately prepare the compound.

[0073] Both the Sonogashira coupling reaction and the Suzuki coupling reaction involve metal catalysts. Regarding the Sonogashira coupling reaction, Suzuki coupling reaction, and halogenation reaction, the reaction conditions, solvent conditions, and catalytic environment involved are adaptively adjusted based on the chemical structure of the reaction raw materials and the product to be synthesized to ensure the smooth implementation of the reaction. The amount of each raw material involved can be calculated based on the molar ratio of each raw material in the synthesis route and the specific composition of each raw material.

[0074] When the chemical structural formula of the compound is the above-mentioned Chemical Structural Formula I-1, Chemical Structural Formula I-2, Chemical Structural Formula I-3 or Chemical Structural Formula I-4, the synthesis routes of the above-mentioned various types of compounds are respectively described as examples.

[0075] For compound I-1 having the chemical structural formula I-1, wherein Z1 is an alkynyl bond and Z2 is a carbon-carbon single bond, the synthetic route corresponding to the preparation method of this type of compound is shown below.

[0076] wherein R1 and R2 are each independently selected from a linear alkyl group having 1 to 9 carbon atoms or a linear alkoxy group having 1 to 9 carbon atoms; and X1 to X6 are each independently selected from -H, -F, -CH3, -CH2CH3, -OCF3, cyclopropyl, cyclobutyl or cyclohexyl.

[0077] The preparation method of compound I-1 is as follows:

[0078] Monomer S-1 and monomer S-2 are subjected to a Sonogashira coupling reaction catalyzed by a metal catalyst to produce monomer S-3. For example, the reaction temperature may be 40° C. to 120° C., such as 40° C., 50° C., 60° C., 70° C., 80° C., 90° C., 100° C., 110° C., 120° C., etc. The metal catalyst includes, but is not limited to, a palladium catalyst.

[0079] Monomer S-3 and monomer S-4 are subjected to a Sonogashira coupling reaction catalyzed by a metal catalyst to produce monomer S-5. For example, the reaction temperature can be 40° C. to 120° C., such as 40° C., 50° C., 60° C., 70° C., 80° C., 90° C., 100° C., 110° C., 120° C., etc. The metal catalyst includes, but is not limited to, a palladium catalyst.

[0080] Monomer S-5 and monomer S-6 are subjected to a Suzuki coupling reaction catalyzed by a metal catalyst to produce compound I-1. For example, the reaction temperature can be 60° C. to 150° C., for example, 60° C., 70° C., 80° C., 90° C., 100° C., 110° C., 120° C., 130° C., 140° C., 150° C., 160° C., etc. The metal catalyst includes, but is not limited to, a palladium catalyst.

[0081] For compound I-2 having the chemical structural formula I-2, wherein Z1 is an alkynyl bond and Z2 is an alkynyl bond, the synthetic route corresponding to the preparation method of this type of compound is shown below.

[0082] wherein R1 and R2 are each independently selected from a linear alkyl group having 1 to 9 carbon atoms or a linear alkoxy group having 1 to 9 carbon atoms; and X1 to X6 are each independently selected from -H, -F, -CH3, -CH2CH3, -OCF3, cyclopropyl, cyclobutyl or cyclohexyl.

[0083] The preparation method of compound I-2 is as follows:

[0084] Monomer S-1 and monomer S-2 are subjected to a Sonogashira coupling reaction catalyzed by a metal catalyst to produce monomer S-3. For example, the reaction temperature may be 40° C. to 120° C., such as 40° C., 50° C., 60° C., 70° C., 80° C., 90° C., 100° C., 110° C., 120° C., etc. The metal catalyst includes, but is not limited to, a palladium catalyst.

[0085] Monomer S-3 and monomer S-4 are subjected to a Sonogashira coupling reaction catalyzed by a metal catalyst to produce monomer S-5. For example, the reaction temperature can be 40° C. to 120° C., such as 40° C., 50° C., 60° C., 70° C., 80° C., 90° C., 100° C., 110° C., 120° C., etc. The metal catalyst includes, but is not limited to, a palladium catalyst.

[0086] Monomer S-5 and monomer S-7 are subjected to a Sonogashira coupling reaction catalyzed by a metal catalyst to produce compound I-2. For example, the reaction temperature can be 60° C. to 150° C., for example, 60° C., 70° C., 80° C., 90° C., 100° C., 110° C., 120° C., 130° C., 140° C., 150° C., 160° C., etc. The metal catalyst includes, but is not limited to, a palladium catalyst.

[0087] For compound I-3 having the chemical structural formula I-3, wherein Z1 is a carbon-carbon single bond and Z2 is a carbon-carbon single bond, the synthetic route corresponding to the preparation method of this type of compound is shown below.

[0088] wherein R1 and R2 are each independently selected from a linear alkyl group having 1 to 6 carbon atoms or a linear alkoxy group having 1 to 6 carbon atoms; and X1 to X6 are each independently selected from -H, -F, -CH3, -CH2CH3, -OCF3, cyclopropyl, cyclobutyl or cyclohexyl.

[0089] The preparation method of compound I-3 is as follows:

[0090] Monomer S-1 and monomer S-8 are subjected to a Suzuki coupling reaction catalyzed by a metal catalyst to produce monomer S-9. For example, the reaction temperature may be 60° C. to 150° C., such as 60° C., 70° C., 80° C., 90° C., 100° C., 110° C., 120° C., 130° C., 140° C., 150° C., 160° C., etc. The metal catalyst includes, but is not limited to, a palladium catalyst.

[0091] Monomer S-9 is subjected to a bromination reaction with monomer N-bromosuccinimide (NBS) to produce monomer S-10. For example, the reaction temperature may be -78°C to 60°C, such as -70°C, -60°C, -50°C, -40°C, -30°C, -20°C, -10°C, 0°C, 10°C, 20°C, 30°C, 40°C, 50°C, 60°C, etc. The catalyst used includes, but is not limited to, a palladium catalyst.

[0092] Monomer S-10 and monomer S-6 are subjected to a Suzuki coupling reaction catalyzed by a metal catalyst to produce compound I-3. For example, the reaction temperature can be 60° C. to 150° C., for example, 60° C., 70° C., 80° C., 90° C., 100° C., 110° C., 120° C., 130° C., 140° C., 150° C., 160° C., etc. The metal catalyst includes, but is not limited to, a palladium catalyst.

[0093] For compound I-4 having the chemical structural formula I-4, wherein Z1 is a carbon-carbon single bond and Z2 is an alkynyl bond, the synthetic route corresponding to the preparation method of this type of compound is shown below.

[0094] wherein R1 and R2 are each independently selected from a linear alkyl group having 1 to 9 carbon atoms or a linear alkoxy group having 1 to 9 carbon atoms; and X1 to X6 are each independently selected from -H, -F, -CH3, -CH2CH3, -OCF3, cyclopropyl, cyclobutyl or cyclohexyl.

[0095] The preparation method of compound I-4 is as follows:

[0096] Monomer S-1 and monomer S-8 are subjected to a Suzuki coupling reaction catalyzed by a metal catalyst to produce monomer S-9. For example, the reaction temperature may be 60° C. to 150° C., such as 60° C., 70° C., 80° C., 90° C., 100° C., 110° C., 120° C., 130° C., 140° C., 150° C., 160° C., etc. The metal catalyst includes, but is not limited to, a palladium catalyst.

[0097] Monomer S-9 is subjected to a bromination reaction with monomer N-bromosuccinimide (NBS) to produce monomer S-10. For example, the reaction temperature may be -78°C to 60°C, such as -70°C, -60°C, -50°C, -40°C, -30°C, -20°C, -10°C, 0°C, 10°C, 20°C, 30°C, 40°C, 50°C, 60°C, etc.

[0098] Monomer S-10 and monomer S-7 are subjected to a Sonogashira coupling reaction catalyzed by a metal catalyst to produce compound I-4. For example, the reaction temperature can be 40° C. to 120° C., for example, 40° C., 50° C., 60° C., 70° C., 80° C., 90° C., 100° C., 110° C., 120° C., etc. The metal catalyst includes, but is not limited to, a palladium catalyst.

[0099] When synthesizing the above-mentioned compounds based on step-by-step polymerization reactions, the reaction products can be purified after each step of the reaction to achieve the purpose of purification. Some applicable purification methods include but are not limited to at least one of chromatography, recrystallization, sublimation, and adsorption.

[0100] On the other hand, the embodiments of the present disclosure also provide a liquid crystal material, which includes a first liquid crystal monomer and a second liquid crystal monomer, the first liquid crystal monomer includes any of the compounds described above, and the second liquid crystal monomer is configured so that under a temperature condition less than or equal to 0°C, no crystallization occurs after the second liquid crystal monomer is mixed with the first liquid crystal monomer.

[0101] In some examples, the first liquid crystal monomer is selected from one of the compounds provided in the embodiments of the present disclosure. For example, the first liquid crystal monomer includes one of compound I-1, compound I-2, compound I-3, and compound I-4.

[0102] In other examples, the first liquid crystal monomer is selected from two or more of the compounds provided in the embodiments of the present disclosure. For example, the first liquid crystal monomer includes at least two of compound I-1, compound I-2, compound I-3, and compound I-4.

[0103] The mass percentage of the first liquid crystal monomer in the liquid crystal material can be 0.5%-70%. Exemplarily, the mass percentage of the first liquid crystal monomer in the liquid crystal material includes but is not limited to 1%-50%, 1%-30%, 3%-20%, etc. Some examples of the mass percentage of the first liquid crystal monomer include but are not limited to: 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, etc.

[0104] The liquid crystal material provided by the embodiments of the present disclosure is based on the use of any of the above-mentioned compounds provided by the embodiments of the present disclosure as the first liquid crystal monomer. The first liquid crystal monomer and the second liquid crystal monomer work synergistically to enable it to have at least a higher birefringence, a wider nematic phase temperature, and excellent low-temperature stability.

[0105] In the embodiment of the present disclosure, the second liquid crystal monomer is configured so that, under a temperature condition less than or equal to 0° C., no crystallization occurs after the second liquid crystal monomer is mixed with the first liquid crystal monomer.

[0106] For example, the temperature less than or equal to 0° C. may be a temperature condition of 0° C., a temperature condition of -5° C., a temperature condition of -10° C., a temperature condition of -15° C., a temperature condition of -20° C., or the like.

[0107] By combining the first liquid crystal monomer with the second liquid crystal monomer, they work synergistically so that the prepared liquid crystal material has the advantages of higher birefringence, wider nematic phase temperature, excellent low-temperature stability, excellent high-temperature stability, and excellent UV resistance.

[0108] For example, some second liquid crystal monomers that are suitable for having good compatibility with the first liquid crystal monomer and the synergistic effect of the two to optimize the performance of the liquid crystal material are selected from at least one of compound II-1, compound II-2, compound II-3, compound II-4, compound II-5, compound II-6, compound II-7, and compound II-8.

[0109] The chemical structural formula II-1 corresponding to compound II-1, the chemical structural formula II-2 corresponding to compound II-2, the chemical structural formula II-3 corresponding to compound II-3, the chemical structural formula II-4 corresponding to compound II-4, the chemical structural formula II-5 corresponding to compound II-5, the chemical structural formula II-6 corresponding to compound II-6, the chemical structural formula II-7 corresponding to compound II-7, and the chemical structural formula II-8 corresponding to compound II-8 are shown below:

[0110] Among them, R3-R 12 Each independently selected from a linear alkyl group having 1 to 9 carbon atoms and a linear alkoxy group having 1 to 9 carbon atoms; X7-X 31 Each is independently selected from -H, -F, -CH3, -CH2CH3 or -OCF3.

[0111] For compound II-2, some specific examples include but are not limited to:

[0112] For compound II-4, some specific examples include but are not limited to:

[0113] For compound II-5, some specific examples include but are not limited to:

[0114] For compound II-6, some specific examples include but are not limited to:

[0115] For compound II-7, some specific examples include but are not limited to:

[0116] For compound II-8, some specific examples include but are not limited to:

[0117] The various types of second liquid crystal monomers involved above are all liquid crystal compounds known in the art. These second liquid crystal monomers have good compatibility with the first liquid crystal monomers, especially under low temperature conditions below -20°C, the two can be well soluble in each other without crystallization, which is particularly beneficial for improving the low-temperature stability of the liquid crystal material. In addition, the synergistic use of this type of second liquid crystal monomer and the first liquid crystal monomer can also improve the birefringence, high-temperature stability and UV resistance of the liquid crystal material, and broaden its nematic phase temperature range.

[0118] The second liquid crystal monomer is selected from at least one of compound II-1, compound II-2, compound II-3, compound II-4, compound II-5, compound II-6, compound II-7, and compound II-8.

[0119] Illustratively, the number of liquid crystal compounds contained in the second liquid crystal monomer can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20.

[0120] The above-mentioned compound provided in the embodiments of the present disclosure is defined as Compound I. Compound II-1, Compound II-2, and Compound II-3 are selected to be blended with Compound I to improve the low-temperature stability of the composition. Compound II-4, Compound II-5, and Compound II-6 are selected to be blended with Compound I to improve the birefringence and dielectric constant of the composition. Compound II-8 is selected to be blended with Compound I to improve the nematic phase temperature range of the composition and inhibit the formation of a smectic phase.

[0121] In some examples, the sum of the mass percentage of the first liquid crystal monomer and the mass percentage of the second liquid crystal monomer is 100%. For example, the mass percentage of the second liquid crystal monomer can be 0.5%-95%, including 1%-70%, 5%-60%, 10%-50%, etc.

[0122] Some examples of the mass percentage of the second liquid crystal monomer include, but are not limited to, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, etc.

[0123] In other examples, the liquid crystal material provided by the embodiments of the present disclosure also includes an auxiliary agent, that is, the liquid crystal material includes a first liquid crystal monomer, a second liquid crystal monomer and an auxiliary agent, and the auxiliary agent is selected from at least one of an ultraviolet absorber, an ultraviolet stabilizer, and an antioxidant.

[0124] Based on the total mass of the first liquid crystal monomer and the second liquid crystal monomer as 100 parts, the mass of the auxiliary agent is 0.01 parts to 10 parts, and the mass of the auxiliary agent in the liquid crystal material is 0.05 parts, 0.1 parts, 0.15 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1 parts, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, etc.

[0125] By adding one or more of the above-mentioned additives to the liquid crystal material, the ultraviolet resistance and high-temperature stability of the liquid crystal material can be further improved.

[0126] For example, some applicable UV absorbers are selected from at least one of benzotriazole UV absorbers and triazine UV absorbers; UV stabilizers are selected from hindered amine UV stabilizers; and antioxidants are selected from hindered phenol antioxidants.

[0127] For example, the chemical structural formulas of some suitable additives are shown below, and n in the following chemical structural formulas represents an integer of 1-20, R 13 -R 16 Each is selected from a straight-chain alkyl group having 1 to 10 carbon atoms or a straight-chain alkoxy group having 1 to 10 carbon atoms.

[0128] Some examples of hindered amine UV stabilizers are listed below:

[0129] Some examples of benzotriazole UV absorbers are shown below:

[0130] Some examples of triazine UV absorbers are shown below:

[0131] Some examples of hindered phenol antioxidants (including fully hindered phenol antioxidants and semi-hindered phenol antioxidants) are shown below:

[0132] The liquid crystal material provided in the embodiments of the present disclosure is a composition (i.e., a liquid crystal composition). When preparing the liquid crystal material provided in the embodiments of the present disclosure, according to the ratio of each component therein, one or more of the following mixing methods can be used to mix the components: heating to dissolve the mixture method, ultrasonic method, suspension mixing method, etc., so as to prepare a liquid crystal material with uniform texture.

[0133] The liquid crystal material involved in the embodiments of the present disclosure has at least one of the following characteristics: no crystallization at -60°C to 0°C; no color change at 0°C to 150°C; no change at less than or equal to 80mW / cm 2 In some examples, the liquid crystal material involved in the embodiments of the present disclosure has the above three characteristics at the same time.

[0134] The feature "no crystallization at -60°C to 0°C" indicates that the liquid crystal material has excellent low-temperature stability, enabling the liquid crystal material to be stably stored under low-temperature conditions. For example, the storage temperatures at which the liquid crystal material does not crystallize include, but are not limited to, -60°C, -55°C, -50°C, -45°C, -40°C, -35°C, -30°C, -25°C, -20°C, -15°C, -10°C, -5°C, and 0°C.

[0135] The characteristic of "no discoloration at 0°C to 150°C" indicates that the liquid crystal material has excellent high-temperature stability, enabling it to operate stably under high-temperature conditions. For example, the operating temperatures at which the liquid crystal material does not change color include, but are not limited to, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, and 140°C.

[0136] Features "less than or equal to 80mW / cm 2 The liquid crystal material does not change color under UV intensities of 10mW / cm2, which indicates that the liquid crystal material has excellent UV resistance, so that the liquid crystal material can work stably under UV conditions. For example, the UV intensity at which the liquid crystal material does not change color is not limited to: 10mW / cm2 2 , 20mW / cm 2 、30mW / cm 2 , 40mW / cm 2 , 50mW / cm 2 、60mW / cm 2 , 70mW / cm 2 、80mW / cm 2 wait.

[0137] On the other hand, the embodiments of the present disclosure further provide an optoelectronic device, which includes a packaging structure and a liquid crystal material encapsulated inside the packaging structure, wherein the liquid crystal material is any of the liquid crystal materials involved in the embodiments of the present disclosure mentioned above.

[0138] The optoelectronic device provided by the embodiments of the present disclosure has all the advantages of the above-mentioned liquid crystal materials.

[0139] Exemplarily, the optoelectronic device includes but is not limited to a wavelength selection switch, a microwave antenna or a display device, wherein the display device includes but is not limited to: a display screen (for example, a liquid crystal display screen, a vehicle-mounted head-up display, a holographic display, etc.), a liquid crystal lamp (for example, a vehicle-mounted smart liquid crystal lamp), and glasses (for example, AR / VR glasses).

[0140] In some examples, embodiments of the present disclosure further provide a wavelength selective switch, which includes a liquid crystal layer, and the liquid crystal layer uses any of the liquid crystal materials mentioned above in the embodiments of the present disclosure.

[0141] The specific embodiments of the present invention will be described in more detail below. Although the specific embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. Where specific techniques or conditions are not specified in the examples, they are performed according to the techniques or conditions described in the literature in this area or according to the product specifications. Where the manufacturers of the reagents or instruments are not specified, they are all conventional products that can be obtained commercially.

[0142] The following defines or formulates evaluation criteria for the relevant parameters involved in each embodiment, as shown below.

[0143] (1) The clearing point (Cp) of the liquid crystal monomer and the liquid crystal composition was measured by differential scanning calorimetry (DSC). When the clearing point was measured, the heating rate was 5°C / min.

[0144] (2) The birefringence of the liquid crystal monomer and the liquid crystal composition was measured using an Abbe refractometer at 25°C and a wavelength of 589 nm.

[0145] (3) Δε represents the dielectric anisotropy of the liquid crystal monomer / liquid crystal composition at 25°C and 1 kHz. 1 H NMR stands for hydrogen nuclear magnetic resonance. 13 C NMR stands for carbon nuclear magnetic resonance, 19 F NMR stands for fluorine nuclear magnetic resonance spectroscopy, and the testing instrument is a 400 MHz or 500 MHz nuclear magnetic resonance spectrometer produced by Bruker.

[0146] (4) Low temperature stability test: The liquid crystal composition sample was placed in a refrigerator at -30°C and stored for 20 days. No crystallization indicates excellent low temperature stability, while crystallization indicates poor low temperature stability, which needs to be further improved.

[0147] (5) UV resistance test: The liquid crystal composition was injected into the liquid crystal cell by capillary crystallization, and the irradiation intensity was 50 mW / cm2 using a 365 nm ultraviolet lamp. 2After irradiation with 10 J, the color change of the liquid crystal cell was evaluated and used as an evaluation index for the UV resistance. The evaluation criteria are shown in Table 1.

[0148] Table 1

[0149] (6) High-temperature stability test: The liquid crystal composition was injected into the liquid crystal cell by capillary crystallization. The sealing adhesive was cured by irradiation at 365 nm. After heating in a high-temperature oven at 100°C for 100 hours, the color change of the liquid crystal cell was evaluated and used as an evaluation index of high-temperature stability. The evaluation criteria are shown in Table 2:

[0150] Table 2

[0151] In addition, for the compounds corresponding to the liquid crystal monomers and auxiliary agents involved in the following embodiments, these compounds all include multiple groups or bonds. The relevant groups or bonds involved are represented by the codes shown in Table 3. In this way, according to the positions of the multiple groups and bonds in the chemical structure of the corresponding compounds, they are combined in this order using the codes, so as to clearly name the compounds. Moreover, the chemical structure of the compounds can also be inferred based on the compound codes.

[0152] Table 3

[0153] Example 1

[0154] This Example 1 provides a compound named 3UTP(1)S4, whose chemical structure is shown below.

[0155] The synthetic route of compound 3UTP(1)S4 is as follows:

[0156] Combined with the synthetic route of compound 3UTP(1)S4, the preparation method of compound 3UTP(1)S4 is as follows.

[0157] (1) Preparation of 2-ethynyl-1,3-difluoro-5-propylbenzene (monomer S-12)

[0158] Under nitrogen protection, 1,3-difluoro-2-iodo-5-propylbenzene (monomer S-11), ethynyltrimethylsilane, cuprous iodide, bis(triphenylphosphine)palladium dichloride and triethylamine solution were added to a round-bottom flask and heated with stirring to react. The reaction system was cooled to room temperature, extracted with an extractant (the extractant includes but is not limited to ethyl acetate), the organic phases were combined, dried over magnesium sulfate, and dried under reduced pressure. Potassium carbonate, a mixed solution of methanol and dichloromethane (the two can be in any volume ratio) were added to the system, and after continued stirring, distilled water was added, extracted with an extractant, the organic phases were combined, dried under reduced pressure, and separated by column chromatography to obtain monomer S-12.

[0159] (2) Preparation of 2-((4-bromo-3-methylphenyl)acetylene)-1,3-difluoro-5-propylbenzene (monomer S-13)

[0160] Under nitrogen, 2-ethynyl-1,3-difluoro-5-propylbenzene (monomer S-12), 2-bromo-5-iodotoluene, cuprous iodide, bis(triphenylphosphine)palladium dichloride, and triethylamine solution were added to a round-bottom flask and heated with stirring to react. After the system cooled to room temperature, an extractant was added for extraction. The organic phases were combined, dried over magnesium sulfate, and evaporated to dryness under reduced pressure. Monomer S-13 was then separated by column chromatography.

[0161] (3) Preparation of compound 3UTP(1)S4

[0162] Under nitrogen protection, 2-((4-bromo-3-methylphenyl)acetylene)-1,3-difluoro-5-propylbenzene (monomer S-13), 5-butyl-2-thieno[3,2-b]thiopheneboronic acid, potassium carbonate, tetrakis(triphenylphosphine)palladium, and a mixed solution of 1,4-dioxane and water (the volume ratio of 1,4-dioxane to water is greater than 1) were added to a 500 mL round-bottom flask and heated with stirring for reaction. The mixture was cooled to room temperature, extracted with an extractant, and the organic phases were combined, dried over magnesium sulfate, and evaporated to dryness under reduced pressure. Compound 3UTP(1)S4 was obtained by column chromatography.

[0163] The compound 3UTP(1)S4 was subjected to DSC test, and the test results showed that the phase transition temperature of the compound 3UTP(1)S4 was Cr 73.9℃, N155.4℃I (wherein, Cr represents the crystallization point, N represents the nematic phase, and I represents the clearing point. The data represent that the crystallization temperature is 73.9℃, the nematic phase is at 155.4℃, and the phase is clear when it exceeds 155.4℃). The birefringence △n (589nm, 25℃) of the compound 3UTP(1)S4 is 0.365.

[0164] The structure of the compound 3UTP(1)S4 was identified by hydrogen-NMR spectroscopy, carbon-NMR spectroscopy and fluorine-NMR spectroscopy. The test results are as follows:

[0165] 1 H-NMR (500M, CDCl3) δ (ppm): 7.51 (s, 1H), 7.44 (s, 2H), 7.20 (s, 1H), 6.98 (s, 1H), 6.79-6.78 (d, 2H), 2.94-2.91 (t , 2H), 2.62-2.59(t, 2H), 2.50(s, 3H), 1.77-1.71(m, 2H), 1.69-1.64(m, 2H), 1.48-1.44(m, 2H), 1.00-0.96(m, 6H).

[0166] 13 C-NMR(125M, CDCl3)δ(ppm):163.79,163.74,161.78,161.73,148.28,146.20 ,146.13,146.06,142.38,138.90,137.47,136.12,135.08,134.02,130.32,12 9.25,122.11,119.13,116.26,111.29,111.25,111.13,111.10,99.73,99.58,99.42,98.26,98.23,37.88,33.71,30.85,23,77,22.17,21.14,13.79,13.56.

[0167] 19 F NMR (376M, CDCl3) δ (ppm): -108.54, -108,56.

[0168] It can be seen that the chemical structure of the compound 3UTP(1)S4 prepared in Example 1 is consistent with its chemical structural formula.

[0169] Example 2

[0170] This Example 2 provides a compound named 3UTGTS5, whose chemical structure is shown below.

[0171] The synthetic route of compound 3UTGTS5 is as follows:

[0172] Combined with the synthetic route of compound 3UTGTS5, the preparation method of compound 3UTGTS5 is as follows.

[0173] (1) Preparation of 2-ethynyl-1,3-difluoro-5-propylbenzene (monomer S-12)

[0174] The preparation method of 2-ethynyl-1,3-difluoro-5-propylbenzene (monomer S-12) is the same as that in Example 1 and will not be repeated here.

[0175] (2) Preparation of 2-((4-bromo-3-fluorophenyl)acetylene)-1,3-difluoro-5-propylbenzene (monomer S-14)

[0176] Under nitrogen, a round-bottom flask was charged with 2-ethynyl-1,3-difluoro-5-propylbenzene (monomer S-12), 1-bromo-2-fluoro-4-iodobenzene, cuprous iodide, bis(triphenylphosphine)palladium dichloride, and a triethylamine solution. The mixture was heated and stirred to react. After the system cooled to room temperature, an extractant was added. The organic phases were combined, dried over magnesium sulfate, and evaporated to dryness under reduced pressure. Monomer S-14 was then isolated by column chromatography.

[0177] (3) Preparation of compound 3UTGTS5

[0178] Under nitrogen, a round-bottom flask was charged with 2-((4-bromo-3-fluorophenyl)ethynyl)-1,3-difluoro-5-propylbenzene (monomer S-14), 2-ethynyl-5-pentylthieno[3,2-b]thiophene, cuprous iodide, tetrakis(triphenylphosphine)palladium, and a mixed solution of N,N-dimethylformamide and triethylamine (the volume ratio of N,N-dimethylformamide to triethylamine being greater than 1) and heated with stirring to react. After the system cooled to room temperature, an extractant was added, and the organic phases were combined, dried over magnesium sulfate, and evaporated to dryness under reduced pressure. Compound 3UTGTS5 was isolated by column chromatography.

[0179] The DSC test of the compound 3UTGTS5 showed that the phase transition temperature of the compound 3UTGTS5 was Cr 94.1°C I, and the birefringence Δn (589 nm, 25°C) of the compound 3UTGTS5 was 0.525.

[0180] The structure of the compound 3UTGTS5 was identified by hydrogen-NMR spectroscopy, carbon-NMR spectroscopy, and fluorine-NMR spectroscopy. The test results are as follows:

[0181] 1 H-NMR(500M, CDCl3)δ(ppm):7.49-7.46(t,1H),7.42(s,1H),7.34-7.29(m,2H),6.92(s,1H),6.79-6.77(d,2H),2 .91-2.88(t,2H),2.61-2.58(t,2H),1.77-1.71(m,2H),1.69-1.62(m,2H),1.39-1.37(m,4H),0.97-0,91(m,6H).

[0182] 13C-NMR (125M, CDCl3) δ (ppm): 163.80, 163.75, 162.83, 161.78, 160.82, 151.10, 146. 88,146.81,140.48,135.47,132.88,127.48,124.41,124.34,121.92,119.05,118.4 0,116.32,113.20,112.30,111.36,111.32,111.20,111.17,99.13,98.97,98.81,96.12,89.42,85.44,79.42,37.91,31.27,31.24,31.09,23.71,22.37,14.42,13.53.

[0183] 19 F NMR (376M, CDCl3) δ (ppm): -108.19, -108.21, -109.59, -109.61.

[0184] It can be seen that the chemical structure of compound 3UTGTS5 prepared in Example 2 is consistent with its chemical structural formula.

[0185] Example 3

[0186] This Example 3 provides a compound named 4UTP(1)S3, whose chemical structure is shown below.

[0187] The synthetic route of compound 4UTP(1)S3 is as follows:

[0188] In combination with the synthetic route of compound 4UTP(1)S3, the preparation method of compound 4UTP(1)S3 is as follows.

[0189] (1) Preparation of 2-ethynyl-1,3-difluoro-5-butylbenzene (monomer S-16)

[0190] Under nitrogen protection, 1,3-difluoro-2-iodo-5-butylbenzene (monomer S-15), ethynyltrimethylsilane, cuprous iodide, bis(triphenylphosphine)palladium dichloride and triethylamine solution are added in a round-bottomed flask and heated and stirred for reaction. The question response system is cooled to room temperature, an extraction agent is added for extraction, and the organic phase is merged, dried over magnesium sulfate, and decompression is spin-dried for. In this system, salt of wormwood, a mixed solution of methanol and dichloromethane solution (the volume ratio of the two can be any ratio) are added, after continuing the stirring reaction, distilled water is added, the extraction agent is adopted to extract, the organic phase is merged, the decompression is spin-dried for, and the monomer S-16 is separated by column chromatography.

[0191] (2) Preparation of 2-((4-bromo-3-methylphenyl)acetylene)-1,3-difluoro-5-butylbenzene (monomer S-17)

[0192] Under nitrogen, 2-ethynyl-1,3-difluoro-5-butylbenzene (monomer S-16), 2-bromo-5-iodotoluene, cuprous iodide, bis(triphenylphosphine)palladium dichloride, and triethylamine solution were added to a round-bottom flask and heated with stirring to react. After the system cooled to room temperature, an extractant was added. The organic phases were combined, dried over magnesium sulfate, and evaporated to dryness under reduced pressure. Monomer S-17 was then isolated by column chromatography.

[0193] (3) Preparation of compound 4UTP(1)S3

[0194] Under nitrogen protection, 2-((4-bromo-3-methylphenyl)acetylene)-1,3-difluoro-5-butylbenzene (monomer S-17), 5-propyl-2-thieno[3,2-b]thiopheneboronic acid, potassium carbonate, tetrakis(triphenylphosphine)palladium, and a mixed solution of 1,4-dioxane and water (the volume ratio of 1,4-dioxane to water should be greater than 1) were added to a round-bottom flask and heated with stirring for reaction. The mixture was cooled to room temperature, extracted with an extractant, and the organic phases were combined, dried over magnesium sulfate, and evaporated to dryness under reduced pressure. Compound 4UTP(1)S3 was obtained by column chromatography.

[0195] The DSC test of the compound 4UTP(1)S3 showed that the phase transition temperature of the compound 4UTP(1)S3 was 92.0°C for Cr and 160.2°C for N, and the birefringence Δn (589nm, 25°C) of the compound 4UTP(1)S3 was 0.363.

[0196] The structure of the compound 4UTP(1)S3 was identified by hydrogen-NMR spectroscopy, carbon-NMR spectroscopy and fluorine-NMR spectroscopy. The test results are as follows:

[0197] 1 H-NMR (500M, CDCl3) δ (ppm): 7.50 (s, 1H), 7.44 (s, 2H), 7.20 (s, 1H), 6.98 (s, 1H), 6.79-6.77 (d, 2H), 2.91-2.88 (t, 2H), 2.6 4-2.61 (t, 2H), 2.50 (s, 3H), 1.80-1.76 (m, 2H), 1.64-1.58 (m, 2H), 1.41-1.35 (m, 2H), 1.05-1.02 (t, 3H), 0.97-0.94 (t, 3H).

[0198] 13C-NMR(125M, CDCl3)δ(ppm):163.78,163.73,161.77,161.72,148.03,146 .44,146.36,146.29,142.39,138.89,137.50,136.55,135.07,134.01,131 .04,129.24,122.71,119.12,116.35,111.23,111.20,111.08,111.04,99. 67,99.51,98.17,36.04,33.20,32.72,25.84,22.98,21.13,13.79,13.64.

[0199] 19 F NMR (376M, CDCl3) δ (ppm): -108.54, -108.56.

[0200] It can be seen that the chemical structure of the compound 4UTP(1)S3 prepared in Example 3 is consistent with its chemical structural formula.

[0201] Example 4

[0202] This embodiment 4 provides a liquid crystal composition, which includes a first liquid crystal monomer, a second liquid crystal monomer and an auxiliary agent. The first liquid crystal monomer is the compound 4UTP(1)S3 prepared in embodiment 3. The second liquid crystal monomer includes a plurality of liquid crystal compounds. The chemical structures of these liquid crystal compounds can be reversely deduced based on the corresponding code names in Table 4.

[0203] The sum of the mass percentages of the liquid crystal compounds in the first liquid crystal monomer and the second liquid crystal monomer is 100%. The total mass of the first liquid crystal monomer and the second liquid crystal monomer is defined as 100 parts by weight, and the mass of the auxiliary agent is 0.6 parts by weight.

[0204] The formula of the liquid crystal composition is shown in Table 4. The components in Table 4 are placed in a sample bottle equipped with a magnet, heated and stirred until clear, and cooled to room temperature to prepare the liquid crystal composition.

[0205] Table 4

[0206] The components of the liquid crystal composition provided in Example 4 have good compatibility. According to tests, the clearing point (Cp) of the liquid crystal composition provided in Example 4 is 124° C., and the birefringence Δn at 25° C. and 589 nm is 0.3279.

[0207] Example 5

[0208] This embodiment 5 provides a liquid crystal composition, which includes a first liquid crystal monomer, a second liquid crystal monomer and an auxiliary agent. The first liquid crystal monomer is the compound 3UTGTS5 prepared in embodiment 2. The second liquid crystal monomer includes a plurality of liquid crystal compounds. The chemical structures of these liquid crystal compounds can be reversely deduced based on the corresponding code names in Table 5.

[0209] The sum of the mass percentages of the liquid crystal compounds in the first liquid crystal monomer and the second liquid crystal monomer is 100%. The total mass of the first liquid crystal monomer and the second liquid crystal monomer is defined as 100 parts by weight, and the mass of the auxiliary agent is 1 part by weight.

[0210] The formula of the liquid crystal composition is shown in Table 5. The components in Table 5 are placed in a sample bottle equipped with a magnet, heated and stirred until clear, and cooled to room temperature to prepare the liquid crystal composition.

[0211] Table 5

[0212] The components of the liquid crystal composition provided in Example 5 have good compatibility. According to tests, the clearing point (Cp) of the liquid crystal composition provided in Example 5 is 147° C., and the birefringence Δn at 25° C. and 589 nm is 0.3659.

[0213] Example 6

[0214] This embodiment 6 provides a liquid crystal composition, which includes a first liquid crystal monomer and a second liquid crystal monomer. The first liquid crystal monomer is the compound 4UTP(1)S3 prepared in embodiment 3, and the second liquid crystal monomer includes a plurality of liquid crystal compounds. The chemical structures of these liquid crystal compounds can be reversely deduced based on the corresponding code names in Table 6.

[0215] The sum of the mass percentages of the liquid crystal compounds in the first liquid crystal monomer and the second liquid crystal monomer is 100%, and the total mass of the first liquid crystal monomer and the second liquid crystal monomer is defined as 100 parts by weight.

[0216] The formula of the liquid crystal composition is shown in Table 6. The components in Table 6 are placed in a sample bottle equipped with a magnet, heated and stirred until clear, and cooled to room temperature to prepare the liquid crystal composition.

[0217] Table 6

[0218] The components of the liquid crystal composition provided in Example 6 have good compatibility. According to tests, the clearing point (Cp) of the liquid crystal composition provided in Example 6 is 131° C., and the birefringence Δn at 25° C. and 589 nm is 0.3399.

[0219] Comparative Example 1

[0220] This comparative example 1 provides a liquid crystal composition, which includes a plurality of liquid crystal compounds and auxiliary agents. The chemical structures of these liquid crystal compounds can be reversely deduced according to the corresponding code names in Table 7.

[0221] The formula of the liquid crystal composition of Comparative Example 1 is shown in Table 7. The components in Table 7 are placed in a sample bottle equipped with a magnet, heated and stirred until clear, and cooled to room temperature to prepare the liquid crystal composition.

[0222] Table 7

[0223] According to tests, the clearing point (Cp) of the liquid crystal composition provided in Comparative Example 1 is 140° C., and the birefringence Δn at 25° C. and 589 nm is 0.4440.

[0224] Comparative Example 2

[0225] Comparative Example 2 provides a liquid crystal composition comprising a plurality of liquid crystal compounds and auxiliary agents. The chemical structures of these liquid crystal compounds can be inferred from the corresponding code names in Table 8.

[0226] The formula of the liquid crystal composition of Comparative Example 2 is shown in Table 8. The components in Table 8 are placed in a sample bottle equipped with a magnet, heated and stirred until clear, and cooled to room temperature to prepare the liquid crystal composition.

[0227] Table 8

[0228] According to tests, the clearing point (Cp) of the liquid crystal composition provided in Comparative Example 2 is 134° C., and the birefringence Δn at 25° C. and 589 nm is 0.3569.

[0229] Test Case

[0230] This test example tests the relevant properties of the liquid crystal compositions provided in Example 4, Example 5, Example 6, Comparative Example 1 and Comparative Example 2, respectively. The test results are shown in Tables 9 to 11, respectively.

[0231] Table 9

[0232] Table 10

[0233] Table 11

[0234] In summary, based on the use of compound I provided in the embodiments of the present disclosure as the first liquid crystal monomer, and its synergistic effect with the second liquid crystal monomer and the optional auxiliary agent, the liquid crystal compositions prepared in Examples 4, 5 and 6 have the following beneficial effects: higher birefringence, stronger low-temperature stability, stronger high-temperature stability, excellent UV resistance, and a wider nematic phase temperature range.

[0235] The above description is only for the purpose of facilitating those skilled in the art to understand the technical solutions of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the scope of protection of the present disclosure.

Claims

1. A compound, wherein The compound includes a first chain hydrocarbon group, a first phenyl group, a second phenyl group, a thieno[3,2-b]thienyl group, and a second chain hydrocarbon group; The first chain hydrocarbon group is connected to one of the carbon atoms of the first phenyl group, another carbon atom of the first phenyl group is connected to one of the carbon atoms of the second phenyl group through a first connecting bond, another carbon atom of the second phenyl group is connected to one of the carbon atoms of the thieno[3,2-b]thienyl group through a second connecting group, and another carbon atom of the thieno[3,2-b]thienyl group is connected to the second chain hydrocarbon group; The first phenyl group has one or two first substituents, the first substituents are adjacent to the carbon atom connected to the first connecting bond in the first phenyl group, and the first substituents are F, -CF3 or -OCF3; The first chain hydrocarbon group and the second chain hydrocarbon group are selected from a straight chain alkyl group, a straight chain alkoxy group, a straight chain fluoroalkyl group, a straight chain alkenyl group, a straight chain alkenyloxy group or a difluorovinyl group.

2. The compound according to claim 1, wherein The first chain hydrocarbon group and the second chain hydrocarbon group are each independently selected from a straight-chain alkyl group having 1 to 9 carbon atoms, a straight-chain alkoxy group having 1 to 9 carbon atoms, a straight-chain fluoroalkyl group having 1 to 9 carbon atoms, a straight-chain alkenyl group having 2 to 9 carbon atoms, a straight-chain alkenyloxy group having 2 to 9 carbon atoms, or a difluorovinyl group having 2 to 9 carbon atoms.

3. The compound according to claim 1 or 2, wherein The second phenyl group is substituted or unsubstituted; The substituted second phenyl group has one or more second substituents, and the second substituents are selected from -F, -CH3, -CH2CH3, -OCF3, cyclopropyl, cyclobutyl or cyclohexyl.

4. The compound according to any one of claims 1 to 3, wherein The first connecting bond and the second connecting bond are each independently selected from a carbon-carbon single bond, a carbon-carbon double bond, an alkynyl bond, an ester bond or a difluoromethyl ether bridge bond.

5. The compound according to any one of claims 1 to 4, wherein The chemical structural formula of the compound is shown below: wherein R1 and R2 represent a first chain hydrocarbon group and a second chain hydrocarbon group, respectively, and both are independently selected from a straight-chain alkyl group having 1 to 9 carbon atoms, a straight-chain alkoxy group having 1 to 9 carbon atoms, a straight-chain fluoroalkyl group having 1 to 9 carbon atoms, a straight-chain alkenyl group having 2 to 9 carbon atoms, a straight-chain alkenyloxy group having 2 to 9 carbon atoms, or a difluorovinyl group having 2 to 9 carbon atoms; Z1 and Z2 represent the first connecting bond and the second connecting bond, respectively, and are independently selected from and independently represent a carbon-carbon single bond, a carbon-carbon double bond, an alkynyl group, an ester group or a difluoromethyl ether bridge bond; X1, and X4-X6 are each independently selected from -H, -F, -CH3, -CH2CH3, -OCF3, cyclopropyl, cyclobutyl or cyclohexyl; At least one of X2 and X3 is F, -CF3 or -OCF3.

6. The compound according to claim 5, wherein The compound is compound I-1, compound I-2, compound I-3 or compound I-4; The chemical structural formula I-1 corresponding to the compound I-1, the chemical structural formula I-2 corresponding to the compound I-2, the chemical structural formula I-3 corresponding to the compound I-3, and the chemical structural formula I-4 corresponding to the compound I-4 are shown below: Wherein, R1 and R2 are each independently selected from a straight-chain alkyl group having 1 to 9 carbon atoms or a straight-chain alkoxy group having 1 to 9 carbon atoms.

7. Use of the compound according to any one of claims 1 to 6 in liquid crystal materials.

8. A method for preparing a compound according to any one of claims 1 to 6, wherein: The preparation method comprises: According to the chemical structure of the compound, determining a plurality of monomers for synthesizing the compound; The compound is prepared by gradually reacting multiple monomers; The reaction includes at least one of a Sonogashira coupling reaction, a Suzuki coupling reaction, and a halogenation reaction.

9. A liquid crystal material, wherein: The liquid crystal material comprises a first liquid crystal monomer and a second liquid crystal monomer, wherein the first liquid crystal monomer comprises the compound according to any one of claims 1 to 6; The second liquid crystal monomer is configured such that, under a temperature condition of less than or equal to 0° C., after the second liquid crystal monomer is mixed with the first liquid crystal monomer, no crystallization occurs.

10. The liquid crystal material according to claim 9, wherein: The second liquid crystal monomer is selected from at least one of compound II-1, compound II-2, compound II-3, compound II-4, compound II-5, compound II-6, compound II-7, and compound II-8; The chemical structural formula II-1 corresponding to the compound II-1, the chemical structural formula II-2 corresponding to the compound II-2, the chemical structural formula II-3 corresponding to the compound II-3, the chemical structural formula II-4 corresponding to the compound II-4, the chemical structural formula II-5 corresponding to the compound II-5, the chemical structural formula II-6 corresponding to the compound II-6, the chemical structural formula II-7 corresponding to the compound II-7, and the chemical structural formula II-8 corresponding to the compound II-8 are shown as follows: Among them, R3-R 12 Each is independently selected from a straight-chain alkyl group having 1 to 6 carbon atoms and a straight-chain alkoxy group having 1 to 6 carbon atoms; X7-X 31 Each is independently selected from -H, -F, -CH3, -CH2CH3 or -OCF3.

11. The liquid crystal material according to any one of claims 9 to 10, wherein: The liquid crystal material further comprises an auxiliary agent, and the auxiliary agent is selected from at least one of a UV absorber, a UV stabilizer, and an antioxidant.

12. The liquid crystal material according to any one of claims 9 to 10, wherein: The liquid crystal material has at least one of the following characteristics: no crystallization at -60°C to 0°C; no color change at 0°C to 150°C; no change in temperature at less than or equal to 80 mW / cm 2 No discoloration under high UV intensity.

13. An optoelectronic device, wherein: The optoelectronic device comprises a packaging structure and a liquid crystal material packaged inside the packaging structure, wherein the liquid crystal material is the liquid crystal material according to any one of claims 9 to 12.

14. The optoelectronic device according to claim 13, wherein: The optoelectronic device includes a wavelength selective switch, a microwave antenna or a display device.

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