1, 3, 4-thiadiazole liquid crystal compound based on stilbene and preparation method of 1, 3, 4-thiadiazole liquid crystal compound

A technology of liquid crystal compounds and thiadiazoles, applied in 1 field, can solve problems such as insufficient thermal stability, and achieve the effects of excellent thermal stability, high yield, and wide temperature range of liquid crystal phases

Inactive Publication Date: 2016-06-29
NANKAI UNIV
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  • Abstract
  • Description
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Problems solved by technology

1,3,4-Thiadiazoles reported in literature (P.Kumar, etal, J.Mater.Chem.C, 2015, 3, 8166; M.L.Parra, etal, Liq.Cryst. 2008, 35, 55) The liquid crystal temperature range of liquid crystal compounds usually does not exceed 100°C. Our research group (J.Han, et al, Liq.Cryst., 2008, 35, 1379) combined biphenyl groups with 1,3,4-thiadiazole to design Synthesized a liquid crystal compound with a liquid crystal temperature range up to 200°C, but this type of liquid crystal material is partially decomposed when the point is cleared, and the thermal stability is not good enough

Method used

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  • 1, 3, 4-thiadiazole liquid crystal compound based on stilbene and preparation method of 1, 3, 4-thiadiazole liquid crystal compound
  • 1, 3, 4-thiadiazole liquid crystal compound based on stilbene and preparation method of 1, 3, 4-thiadiazole liquid crystal compound
  • 1, 3, 4-thiadiazole liquid crystal compound based on stilbene and preparation method of 1, 3, 4-thiadiazole liquid crystal compound

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] Taking 10-HYD-F as an example to introduce the preparation of intermediate n-HYD-R

[0031] Add 308 mg (2.2 mmol) of 4-fluorobenzoic acid into 10 mL of thionyl chloride and heat to reflux for 8 h. After cooling, remove unreacted thionyl chloride to obtain 4-fluorobenzoyl chloride. 789 mg (2 mmol) of (E)-4-(2-p-decyloxyphenyl) vinylbenzoic hydrazide was dissolved in 50 mL of pyridine, and the resulting pyridine solution was added to p-fluorobenzoyl chloride. Heat to maintain the reaction system at 90°C. After 2 hours, the reaction was complete, and the solution was cooled to precipitate the product. Suction filtration gave 699 mg of white solid. Yield 71%.

[0032] The structural characterization data for the product 10-HYD-F are: 1 HNMR (400MHz, DMSO-d 6 ): δppm10.55(s, 1H, O=C-N-H), 10.50(s, 1H, O=C-N-H), 8.01(dd, J=8.8, 5.5Hz, 2H, Ar-H), 7.93(d, J= 8.3Hz, 2H, Ar-H), 7.70(d, J=8.3Hz, 2H, Ar-H), 7.57(d, J=8.7Hz, 2H, Ar-H), 7.44-7.30(m, 3H, Ar-HandC=C-H), 7.17(d, ...

Embodiment 2

[0034] Taking 10-THD-F as an example to introduce the preparation of stilbene-based 1,3,4-thiadiazole liquid crystal compound n-THD-R

[0035] Mix 516mg (1mmol) of n-HYD-F and 444mg (1.1mmol) of Lowe's reagent [bis(4-methoxyphenyl)-1,3-dithio-2,4-diphosphonane-2,4- Disulfide] was added to 50mL toluene solution, heated to reflux for 12h, and cooled to room temperature. Toluene was removed under reduced pressure, and the remaining solid was recrystallized from ethanol to obtain a crude product. The crude product was further purified through a silica gel column using chloroform as the eluent to obtain 344 mg of a light yellow solid. The yield was 67%.

[0036] The structural characterization data for the product 10-THD-F are: 1 HNMR (400MHz, CDCl 3 ): δppm8.07-7.95 (m, 4H, Ar-H), 7.59 (d, J=7.6Hz, 2H, Ar-H), 7.47 (d, J=7.6Hz, 2H, Ar-H), 7.24 -7.13(m, 3H, Ar-HandC=C-H), 7.00(d, J=16.8Hz, 1H, C=C-H), 6.91(d, J=8.0Hz, 2H, Ar-H), 3.99(t, J=6.0Hz, 2H, O-CH 2 -CH 2 ), 1.80 (m, 2...

Embodiment 3

[0038] The liquid crystal properties of the compounds of the present invention were studied by polarizing microscope (POM) and differential scanning calorimetry (DSC).

[0039] figure 1 It is the smectic A phase texture diagram of compound 10-THD-F at 325 °C during the cooling process.

[0040] figure 2 It is the differential scanning calorimetry (DSC) diagram of compound 10-THD-F.

[0041] Table 1 shows the phase transition and the corresponding enthalpy change of compound 10-THD-R, where Cr means crystal, N means nematic phase, SmA and SmC mean smectic phase A, smectic phase C, and Iso means isotropy liquid.

[0042] Table 1 Phase transition and enthalpy change of compound 10-THD-R

[0043]

[0044] It can be seen from Table 1 that the target compounds all have a wide liquid crystal temperature range, among which 10-THD-F and 10-THD-CN have liquid crystal temperature ranges of 234.4°C and 234.0°C during the heating process, which is currently the widest liquid crysta...

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Abstract

The invention relates to a 1, 3, 4-thiadiazole liquid crystal compound based on stilbene and a preparation method of 1, 3, 4-thiadiazole liquid crystal compound. The formula of the compound is as shown in formula (I), wherein n=6, 8, 10, 12, 14; R is expressed as F, CN, H, CH3 and CH3O. The compound has the advantages that the compound is good liquid crystal material and is wide in liquid crystal temperature range, high in clearing point, excellent in thermal stability, and the like; the compound has a fluorescence radiation feature, can emit blue fluorescence and is high in fluorescence efficiency; the compound is promising in application prospect in the liquid crystal display field and the photoelectric field.

Description

technical field [0001] The invention belongs to the technical field of liquid crystal materials with luminescent properties and their preparation, and specifically relates to 1,3,4-thiadiazole liquid crystal compounds, their synthesis methods and applications. Background technique [0002] Liquid crystal materials have excellent optical and electrical properties, and are widely used in the production of various display devices, and are one of the most widely used materials in the display field. Currently, the liquid crystal materials used in the display field mainly include biphenyls, phenylcyclohexanes, dicyclohexanes, tolanes, pyrimidines, esters, and organic liquid crystal compounds containing fluorine and halogens. These materials themselves cannot Light-emitting, liquid crystal display devices prepared with it as a host material need to use light-emitting diodes as a backlight source. Designing a liquid crystal material with luminescent properties for use in liquid cry...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09K19/34C09K11/06
CPCC09K11/06C09K19/3497C09K2211/1051
Inventor 韩杰常晓勇孙春王彦美
Owner NANKAI UNIV
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