Preparation and properties of X-type rigid bridging pyrene-triphenylene quadruplex discotic liquid crystal

Abstract

The invention belongs to the field of organic material chemistry, and discloses a preparation method and properties of X-type rigid bridging pyrene-triphenylene quadruplex discotic liquid crystal, and the X-type rigid bridging pyrene-triphenylene quadruplex discotic liquid crystal has a structure as shown in a general formula I. The compound shown in the general formula I is mainly synthesized from a pyrene tetraborate compound and a monobromobenzophenanthrene derivative through Suzuki-Miyaura cross coupling, the reaction condition is mild, the steps are simple and efficient, and the atom utilization rate is high. The compound has thermotropic liquid crystal property, the intermediate phase is a columnar phase (Col) and a nematic phase (N), the melting point and clearing point of the discotic liquid crystal compound are improved by introducing a rigid ring serving as a bridge, the temperature range of the liquid crystal intermediate phase is widened, the variety is enriched, and meanwhile, the compound has good fluorescence emission and quantum yield in a solution and a film aggregation state. The maximum responsivity of the organic photoconductive detector prepared by taking the Py-TP6 as the absorption layer is 1.25 A / W (the power is 1.18 mW / cm < 2 >), 2.40 A / W (the power is 1.52 mW / cm < 2 >) and 9.23 A / W (the power is 0.63 mW / cm < 2 >) at the wavelength of 405 nm, 532 nm and 650 nm respectively.

Description

Technical Field

[0001] This invention belongs to the field of organic materials chemistry, and specifically relates to the preparation and properties of an X-type rigid bridged pyrene-benzophenanthrene tetrad disk liquid crystal. Background Technology

[0002] Organic small-molecule disk-shaped liquid crystals (DLCs) have been extensively studied as a typical soft material over the past few decades. The volume and orientation of the aromatic core and the molecular symmetry in their molecular structure are the main influencing factors in the formation of thermo-induced columnar liquid crystal mesophases. Actively searching for novel π-conjugated polycyclic aromatic hydrocarbon (PAH) disk-shaped liquid crystals can bring novel molecular designs and material properties to organic thin-film optoelectronic devices such as organic light-emitting diodes (OLEDs), organic field-effect transistors (OFETs), organic photovoltaics (OPVs), and organic photoconductive detectors (OPDs). In recent years, commonly reported planar rigid, highly conjugated aromatic cores include benzo[a]phenanthrene, peryleneimide, hexabenzo[a]methyl ether, fluorene, carbazole, and fused thiophene. However, the thermo-induced phase transitions, supramolecular self-assembly stacking, and photophysical properties of rigidly bridged, highly fused, and conformally flexible multi-unit disk-shaped liquid crystal molecules are still not fully understood. Therefore, inventing a class of rigidly bridged multi-unit luminescent disk-shaped liquid crystal molecules with highly conjugated fused-ring aromatic hydrocarbons on their periphery is expected to enrich the multifunctional applications of disk-shaped liquid crystals as optoelectronic functional materials. Based on this, we designed and synthesized a class of pyrene-benzophenanthrene tetramer compounds. We focused on comparing and studying the properties of direct σ-bond (Py-TP6) and tetramer disk-shaped compounds with benzene rings and biphenyl as rigid bridges (Py-Ph-TP6, Py-Ph2-TP6) in terms of liquid crystal properties, self-assembly order, and photophysical properties. We also explored the application of Py-TP6 as an organic thin film in photodetectors, laying the foundation for the further design and construction of organic light-emitting disk-shaped liquid crystal materials. Summary of the Invention

[0003] The purpose of this invention is to provide a method for preparing X-type pyrene-benzophenanthrene tetrad disk liquid crystal and its properties.

[0004] In the synthesis of these compounds, on the one hand, inexpensive pyrene is first used as a starting material, and Br2 substitution is used to generate Py-4Br, which is further reacted with pinacol diboronate to generate the intermediate pyrene borate Py-4Bpin. On the other hand, the polyalkoxy chain monobromobenzophenanthrene derivative TP6-Br is reacted with pinacol diboronate to generate the intermediate pentahexyloxybenzophenanthrene borate TP6-Bpin; further, it is reacted with 1-bromo-4-iodobenzene and 4-bromo-4'-iodo-1,1'-biphenyl respectively via Suzuki coupling reactions to generate TP6-Ph-Br and TP6-Ph2-Br. Finally, the obtained intermediates Py-4Bpin were subjected to Suzuki-Miyaura cross-coupling reactions under Pd catalysis for TP6-Br, TP6-Ph-Br, and TP6-Ph2-Br, respectively, to efficiently obtain pyrene-benzophenanthrene tetrameric disk-shaped liquid crystal compounds Py-TP6, Py-Ph-TP6, and Py-Ph2-TP6, with yields consistently above 60%. The mesocrystalline properties, self-assembly, photophysical properties, and gelation properties of the target compounds obtained in this invention were preliminarily investigated. Studies have shown that they possess a wide mesocrystalline temperature range, can form stable columnar (Col) mesophases, and some compounds can even form nematic (N) phases in the high-temperature region. Furthermore, these compounds exhibit good photoelectric properties in solution or aggregated states, showing potential applications in organic optoelectronic devices.

[0005] To achieve the above-mentioned objectives, the technical solution adopted is: an X-type rigid bridged pyrene-benzophenanthrene tetrameric disk-shaped liquid crystal compound, characterized in that the compound has the following structure I; wherein R = -C n H 2n+1 {n|6<n<10,n∈Z} * Ar is a rigid (or semi-rigid) spacer group, commonly an aromatic ring, a monoheterocyclic ring, a fused heterocyclic ring, and their derivatives. This invention relates to direct σ-single bond linkage and rigid benzene ring / biphenyl linkage. .

[0006] Compared with the prior art, the beneficial effects of the X-type rigid-bridged pyrene-benzophenanthrene tetrameric disk-shaped liquid crystal compound of the present invention with general formula I are: I. The chemical structure is diverse, and the liquid crystal properties can be adjusted by regulating the type or chain length of the R group and the type of Ar, so that the target compound has rich phase states, a wide mesocrystalline temperature range, and excellent optoelectronic properties, making it a potential application prospect in the fields of organic light-emitting diodes, organic field-effect transistors, and organic photovoltaics. Second, the reagents and pharmaceuticals used in the method of this invention are inexpensive and readily available, the reaction conditions are mild, the atom utilization rate is high, the steps are simple and efficient, the post-processing operation is simple, and the yield is high, which meets the basic requirements of laboratory or industrial production. The preparation method of the X-type rigid bridged pyrene-benzophenanthrene tetramer disk-shaped liquid crystal compound of the above general formula I is simple and efficient, and has excellent liquid crystal performance. The present invention will be further described in detail below with reference to specific implementation examples. Attached Figure Description

[0007] Figure 1 The 1H NMR spectrum of the intermediate compound Py-4Bpin obtained in Example 1.

[0008] Figure 2 The image shows the carbon NMR spectrum of the intermediate compound Py-4Bpin obtained in Example 1.

[0009] Figure 3 The 1H NMR spectrum of the intermediate compound TP6-Bpin obtained in Example 2.

[0010] Figure 4 The image shows the carbon NMR spectrum of the intermediate compound TP6-Bpin obtained in Example 2.

[0011] Figure 5 The 1H NMR spectrum of the intermediate compound TP6-Ph-Br obtained in Example 3 is shown.

[0012] Figure 6 The image shows the carbon NMR spectrum of the intermediate compound TP6-Ph-Br obtained in Example 3.

[0013] Figure 7 The 1H NMR spectrum of the intermediate compound TP6-Ph2-Br obtained in Example 4.

[0014] Figure 8 The image shows the carbon NMR spectrum of the intermediate compound TP6-Ph2-Br obtained in Example 4.

[0015] Figure 9 The 1H NMR spectrum of the target compound Py-TP6 obtained in Example 5.

[0016] Figure 10 The image shows the carbon NMR spectrum of the target compound Py-TP6 obtained in Example 5.

[0017] Figure 11 This is a high-resolution mass spectrum of the target compound Py-TP6 obtained in Example 5.

[0018] Figure 12 The image shows the polarization optical texture of the target compound Py-TP6 obtained in Example 5.

[0019] Figure 13 The image shows the DSC chromatogram of the target compound Py-TP6 obtained in Example 5.

[0020] Figure 14 The image shows the XRD pattern of the target compound Py-TP6 obtained in Example 5.

[0021] Figure 15 The 1H NMR spectrum of the target compound Py-Ph-TP6 obtained in Example 6 is shown.

[0022] Figure 16 The image shows the carbon NMR spectrum of the target compound Py-Ph-TP6 obtained in Example 6.

[0023] Figure 17 This is a high-resolution mass spectrum of the target compound Py-Ph-TP6 obtained in Example 6.

[0024] Figure 18 The image shows the polarization optical texture of the target compound Py-Ph-TP6 obtained in Example 6.

[0025] Figure 19 The image shows the DSC chromatogram of the target compound Py-Ph-TP6 obtained in Example 6.

[0026] Figure 20 The image shows the XRD pattern of the target compound Py-Ph-TP6 obtained in Example 6.

[0027] Figure 21 The 1H NMR spectrum of the target compound Py-Ph2-TP6 obtained in Example 7.

[0028] Figure 22 The image shows the carbon NMR spectrum of the target compound Py-Ph2-TP6 obtained in Example 7.

[0029] Figure 23 The high-resolution mass spectra of the target compound Py-Ph2-TP6 obtained in Example 7 are shown.

[0030] Figure 24 The image shows the polarization optical texture of the target compound Py-Ph2-TP6 obtained in Example 7.

[0031] Figure 25 The image shows the DSC chromatogram of the target compound Py-Ph2-TP6 obtained in Example 7.

[0032] Figure 26 The image shows the XRD pattern of the target compound Py-Ph2-TP6 obtained in Example 7.

[0033] Figure 27 Thermogravimetric analysis (TGA) plots of the target compounds Py-TP6, Py-Ph-TP6, and Py-Ph2-TP6 obtained in Examples 5-7.

[0034] Figure 28 The images show the UV-Vis absorption spectra of the target compounds Py-TP6, Py-Ph-TP6 and Py-Ph2-TP6 obtained in Examples 5-7 in organic solvents.

[0035] Figure 29 The fluorescence emission spectra and quantum yields of the target compounds Py-TP6, Py-Ph-TP6 and Py-Ph2-TP6 obtained in Examples 5-7 in organic solvents are shown.

[0036] Figure 30 The fluorescence emission spectra and quantum yields of the target compounds Py-TP6, Py-Ph-TP6 and Py-Ph2-TP6 obtained in Examples 5-7 in thin film state are shown.

[0037] Figure 31 The UV-Vis absorption spectra of the target compounds Py-TP6, Py-Ph-TP6 and Py-Ph2-TP6 obtained in Examples 5-7 in tetrahydrofuran solvents with gradient water content are shown.

[0038] Figure 32 The fluorescence emission spectra of the target compounds Py-TP6, Py-Ph-TP6 and Py-Ph2-TP6 obtained in Examples 5-7 in tetrahydrofuran solvents with gradient water content are shown.

[0039] Figure 33 This document describes the application of the target compound Py-TP6 obtained in Example 5 as an organic thin film material in a UV-Vis organic photoconductive detector. (a) shows the IV characteristic curves and corresponding structural diagrams under dark and 650 nm illumination; (b) shows the IT diagram at 650 nm wavelength; (c) shows the photocurrent curves under different incident light powers; (d) shows the correlation curves between the photocurrent and responsivity trends and the optical power density; (e) shows the statistical results of photocurrent, responsivity, and optical power density of the compound at wavelengths of 405 nm, 532 nm, and 650 nm; and (f) shows a photograph of the fabricated photoconductive detector.

[0040] Figure 34 The attached figure is a summary of the specification, wherein I is the general formula for an X-type rigid-bridged pyrene-benzophenanthrene tetrad disk-shaped liquid crystal compound. Detailed Implementation

[0041] The present invention will be further illustrated by specific embodiments below, but these are not intended to limit the scope of protection of the present invention. Without departing from the concept of the present invention, those skilled in the art can make improvements to the preparation method and the instruments used within the scope of the claims, and these improvements should also be considered within the scope of protection of the present invention.

[0042] Example 1: Synthesis of intermediate Py-4Bpin (1,3,6,8-tetrakis(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)pyrene) A method for preparing 1,3,6,8-tetrakis(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)pyrene Py-4Bpin, the synthesis and steps of which are as follows: At 120 °C, Br2 (3.48 g, 21.75 mmol) was added dropwise to a stirred solution of pyrene (1.0 g, 4.94 mmol) in nitrobenzene (30 mL); the mixture was kept at 120 °C for 5 hours, then cooled to room temperature; the reaction mixture was filtered, and the residue was washed with methanol (50 mL) and acetone (50 mL); after drying under reduced pressure, 2.30 g of a pale yellow solid Py-4Br was obtained, yield: 90%, which was insoluble in all common organic solvents at room temperature; subsequently, 1,3,6,8-tetrabromopyrene Py-4Br (1.0 g, 1.93 mmol), B2Pin2 (2.94 g, 11.59 mmol), CH3COOK (2.27 g, 23.17 mmol), and Pd(dppf)Cl2·CH2Cl2 (3.15 g, 3.86 mmol) were added. 1,4-dioxane (40.0 mL) was added to a dry polytetrafluoroethylene-sealed Schlenk tube under an argon atmosphere; after adding 1,4-dioxane (40.0 mL), the reaction was subjected to three freeze-thaw cycles to remove trace amounts of oxygen, and the reaction was stirred at 90 °C for 24 hours; after the reaction was completed, the reaction mixture was cooled to room temperature and washed with a saline solution; the organic layer was dried with anhydrous MgSO4, evaporated, and the residue was purified by column chromatography using CH2Cl2 as the eluent to obtain a light yellow powder, Py-4Bpin (995.4 mg, 73%); in this example, the structure of the intermediate Py-4Bpin was identified by 1H NMR and 1C NMR spectroscopy. 1 H NMR (C2D2Cl4, TMS, 600MHz) δ (ppm): 9.13 (s, 4H), 8.84 (s, 2H), 1.51 (s, 48H). 13 C10 NMR (C2D2Cl4, 151 MHz) δ (ppm): 140.67, 137.54, 129.25, 123.74,73.60, 24.95.

[0043] Example 2: Synthesis of intermediate TP6-BPin (pentahexyloxybenzophenanthrene borate derivative) A method for preparing a pentahexyloxybenzophenanthrene borate derivative TP6-BPin, the synthesis and steps of which are as follows: In a dry flask under argon atmosphere, TP6-Br (4.0 g, 4.95 mmol), B2Pin2 (2.77 g, 10.89 mmol), Pd(dppf)Cl2·CH2Cl2 (202.14 mg, 0.25 mmol), and CH3COOK (1.46 g, 14.85 mmol) were added; after adding 1,4-dioxane (120.0 mL), the reaction mixture was stirred at 90 °C for 24 hours; then, the reaction mixture was cooled to room temperature and extracted with CH2Cl2; the combined organic layers were dried over anhydrous MgSO4, evaporated, and the residue was purified by column chromatography (elution: petroleum ether / CH2Cl2, 1 / 3, v / v); recrystallization from ethyl acetate and ethanol yielded a white solid TP6-Bpin (3.10 g, 73%); in this example, the structure of the intermediate TP6-Bpin was identified by 1H NMR and 1C NMR spectroscopy. 1 H NMR (CDCl3, TMS, 600MHz) δ (ppm): 8.97 (s, 1H), 8.05 (s, 1H), 7.90 (s,1H), 7.82 (s, 1H), 7.82 (s, 1H), 7.77 (s, 1H), 4.32 (t, J = 6.6 Hz, 2H), 4.26-4.21 (m, 8H), 2.00-1.91 (m, 10H), 1.61-1.57 (m, 15H), 1.45-1.25 (m, 27H), 0.95-0.92 (m, 15H). 13 C NMR (CDCl3, 151 MHz) δ (ppm): 162.01, 150.36,149.47, 148.87, 148.66, 132.67, 132.63, 125.73, 124.18, 122.93, 122.89,122.86, 108.28, 107.41, 106.79, 106.71, 102.99, 70.00, 69.86, 69.38, 69.35,68.52, 31.68, 31.66, 31.56, 29.44, 29.36, 29.33, 25.88, 25.84, 22.65, 22.55, 14.04, 14.00.

[0044] Example 3: Synthesis of intermediate TP6-Ph-Br (2-(4-bromophenyl)-pentahexyloxybenzophenanthrene derivative) A method for preparing a 2-(4-bromophenyl)-pentahexyloxybenzophenanthrene derivative TP6-Ph-Br, the synthesis and steps of which are as follows: Under argon protection, TP6-Bpin (1.00 g, 1.17 mmol), 1-bromo-4-iodobenzene (496.3 mg, 1.75 mmol), K2CO3 (808.2 mg, 5.85 mmol), and Pd(PPh3)4 (135.2 mg, 0.12 mmol) were added to a Schlenk reaction tube; degassed water (5.0 mL) and THF (10.0 mL) were injected into the reaction mixture; the mixture was stirred at 70 °C for 24 hours; then cooled, extracted with CH2Cl2, and dried over MgSO4; the organic solvent was removed by distillation, and the residue was purified by silica gel column chromatography (petroleum ether / CH2Cl2, 3 / 1, v / v); recrystallization from ethyl acetate and ethanol gave TP6-Ph-Br (900.5 mg, 87%) as a white solid; in this example, the structure of the intermediate TP6-Ph-Br was identified by 1H and 1C NMR spectroscopy. 1 H NMR (CDCl3, TMS, 600MHz) δ (ppm): 8.31 (s, 1H), 7.92-7.84 (m, 5H), 7.62-7.58 (m, 4H), 4.25-4.19 (m, 10H), 1.95-1.83 (m, 10H), 1.58-1.34 (m, 30H), 0.94-0.92 (m, 15H). 13 C NMR (CDCl3, 151 MHz) δ (ppm): 154.67, 149.91,149.32, 148.89, 137.76, 131.54, 131.05, 129.76, 129.35, 125.23, 124.89,122.95, 121.13, 107.90, 107.45, 106.91, 106.51, 104.90, 69.86, 69.81, 69.48,69.38, 68.70, 31.69, 31.48, 29.43, 29.37, 29.17, 25.85, 22.65, 22.62, 14.04.

[0045] Example 4: Synthesis of intermediate TP6-Ph2-Br (2-(4'-bromo-[1,1'-biphenyl]-4-yl)-pentahexyloxybenzophenanthrene derivative) A method for preparing a 2-(4'-bromo-[1,1'-biphenyl]-4-yl)-pentahexyloxybenzophenanthrene derivative TP6-Ph2-Br, the synthesis and steps of which are as follows: Under argon protection, TP6-Bpin (300.0 mg, 0.35 mmol), 4-bromo-4'-iodo-1,1'-biphenyl (188.9 mg, 0.53 mmol), K2CO3 (242.5 mg, 1.75 mmol), and Pd(PPh3)4 (40.5 mg, 0.04 mmol) were added to a Schlenk reaction tube; degassed water (5.0 mL) and THF (10.0 mL) were injected into the reaction mixture; the mixture was stirred at 70 °C for 24 h; then cooled, extracted with CH2Cl2 and dried over MgSO4; the organic solvent was removed by distillation, and the residue was purified by silica gel column chromatography (petroleum ether / CH2Cl2, 1.5 / 1, v / v); recrystallization from ethyl acetate and ethanol gave TP6-Ph2-Br (245.7 mg, 0.35 mmol) as a white solid. (mg, 73%); In this embodiment, the structure of the intermediate TP6-Ph2-Br was identified by 1H and 1C NMR spectroscopy: 1 H NMR (CDCl3, TMS, 600MHz) δ (ppm): 8.41 (s, 1H), 7.95 (d, J = 3.6 Hz, 2H), 7.90 (s, 1H), 7.85 (s, 2H), 7.82 (d, J = 8.2 Hz, 2H), 7.69 (d, J = 8.2 Hz, 2H), 7.62-7.60 (m, 2H), 7.57-7.56 (m, 2H), 4.28-4.20 (m, 10H), 2.00-1.90 (m, 8H), 1.88-1.84 (m, 2H), 1.63-1.57 (m, 8H), 1.54-1.49 (m, 2H), 1.44-1.34 (m, 20H), 0.96-0.89 (m, 15H). 13 C NMR (CDCl3, 151 MHz) δ(ppm): 154.90, 149.85, 149.29, 148.82, 139.89, 138.50, 138.31, 131.89,130.41, 129.92, 129.64, 128.66, 126.47, 125.40, 124.87, 123.93, 123.10,122.97, 121.49, 107.90, 107.46, 106.90, 106.53, 104.88, 69.85, 69.81, 69.47,69.35, 68.71, 31.69, 31.68, 31.64, 31.49, 29.43, 29.38, 29.35, 29.18, 25.86, 25.84, 25.80, 22.66, 22.62, 22.60, 14.05, 14.03, 14.00.

[0046] Example 5: Synthesis of the target compound Py-TP6 (pyrene-benzophenanthrene tetrad compound) A method for preparing the pyrene-benzophenanthrene tetrad compound Py-TP6, the synthesis steps of which are as follows: Under argon protection, Py-4Bpin (100.0 mg, 0.14 mmol), TP6-Br (572.2 mg, 0.71 mmol), K2CO3 (391.5 mg, 2.83 mmol), and Pd(PPh3)4 (49.1 mg, 0.04 mmol) were mixed and stirred in a THF / H2O (9.0 mL / 3.0 mL) solvent mixture. The mixture was heated to 70 °C and reacted for 48 hours with stirring. After cooling, the mixture was extracted with CH2Cl2, dried with MgSO4, and the solvent was removed under vacuum. The residue was eluted by silica gel column chromatography (petroleum ether / CH2Cl2, 4 / 1, v / v). Recrystallization from ethyl acetate and ethanol yielded a bright yellow solid, Py-TP6 (273.1 mg, 62%). In this example, the structure of the target compound Py-TP6 was identified by 1H NMR, 1C NMR, high-resolution mass spectrometry, and elemental analysis. 1 H NMR (CDCl3, TMS, 600MHz) δ(ppm): 8.58 (s, 4H), 7.85 (s, 4H), 7.80 (s,4H), 7.79 (s, 6H), 7.78 (s, 4H), 7.26 (s, 8H), 4.26-4.22 (m, 40H), 1.99-1.92(m, 40H), 1.63-1.58 (m, 40H), 1.44-1.38 (m, 80H), 0.96-0.93 (m, 60H). 13 C NMR(CDCl3, 151 MHz) δ (ppm): 153.61, 149.99, 149.38, 149.04, 148.82, 129.33,127.75, 124.84, 124.11, 123.14, 122.83, 122.72, 112.28, 107.70, 107.26,106.84, 106.19, 105.74, 69.86, 69.80, 69.50, 69.46, 69.28, 31.68, 31.66,31.59, 29.42, 29.40, 29.34, 29.32, 29.18, 25.84, 25.82, 25.80, 22.75, 22.65,22.62, 22.52, 14.05, 13.93. HRMS (MALDI): [M] + calcd for C 208 H 290 O 20 , m / z:3110.1743 (100.0%), 3109.1709 (89.3%), 3111.1776 (53.5%), 3108.1676 (39.7%),3112.1810 (27.1%); found, 3110.1740, 3109.1703, 3111.1769, 3108.1666,3112.1806. Elemental analysis: calculated for C 208 H 290 O 20(3110.59), C 80.32%, H 9.40%; found, C 80.15%, H 9.49%. In terms of performance, its good thermal stability, typical liquid crystal texture, wide liquid crystal phase transition range, and mesocrystalline intermediate phase stacking mode were tested using a polarizing microscope with a hot stage (POM), differential scanning calorimetry (DSC), and small-angle / wide-angle X-ray scattering (S / WAXS) techniques. Furthermore, its UV-Vis absorption spectroscopy, fluorescence emission spectroscopy, and fluorescence quantum yield were measured to explore its application as an organic thin film material in UV-Vis organic photoconductive detectors.

[0047] Example 6: Synthesis of the target compound Py-Ph-TP6 (pyrene-benzene ring-benzophenanthrene tetramer compound) A method for preparing a pyrene-benzene ring-benzophenanthrene tetrad compound Py-Ph-TP6, the synthesis steps of which are as follows: Under argon protection, Py-4Bpin (127.8 mg, 0.18 mmol), TP6-Ph-Br (800.0 mg, 0.90 mmol), K2CO3 (500.2 mg, 3.62 mmol), and Pd(PPh3)4 (62.7 mg, 0.05 mmol) were dissolved in THF / H2O (9.0 mL / 3.0 mL) solution. The mixture was stirred in a solvent mixture of mL; the mixture was heated to 70°C under stirring and reacted for 48 hours; after cooling, the mixture was extracted with CH2Cl2, dried with MgSO4, and the solvent was removed under vacuum; the residue was eluted by silica gel column chromatography (petroleum ether / CH2Cl2, 1 / 1.5, v / v); recrystallization from ethyl acetate and ethanol gave a bright yellow solid Py-Ph-TP6 (401.6 mg, 65%); in this example, the structure of the target compound Py-Ph-TP6 was identified by 1H NMR, 1C NMR, high-resolution mass spectrometry, and elemental analysis. 1 H NMR (CDCl3, TMS, 600MHz) δ (ppm): 8.54 (s, 4H), 8.48 (s,4H), 8.29 (s, 2H), 8.02 (s, 4H), 7.99-7.96 (m, 16H), 7.91-7.88 (m, 16H), 4.29-4.24 (m, 40H), 2.00-1.91 (m, 40H), 1.64-1.55 (m, 40H), 1.46-1.33 (m,80H), 0.97-0.93 (m, 40H), 0.90-0.86 (m, 20H). 13C NMR (CDCl3, 151 MHz) δ (ppm): 155.07, 149.86, 149.36, 148.87, 139.80, 137.89, 137.26, 130.35,130.28, 129.97, 129.66, 128.28, 126.30, 125.53, 124.91, 124.07, 123.17,107.98, 107.59, 107.01, 106.68, 105.07, 69.89, 69.86, 69.52, 69.39, 68.83,31.70, 31.69, 31.62, 31.57, 29.45, 29.40, 29.36, 29.28, 25.98, 25.87, 25.85,25.83, 22.67, 22.60, 14.06, 14.00. HRMS (MALDI): [M] + calcd for C 232 H 306 O 20 , m / z: 3414.2995 (100.0%), 3413.2961 (80.1%), 3415.3028 (66.2%), 3416.3062(51.0%), 3412.2928 (31.9%); found, 3414.2981, 3415.3011, 3413.2953,3416.3032, 3412.2915. Elemental analysis: calculated for C 232 H 306 O 20 (3414.98), C 81.60%, H 9.03%; found, C 81.77%, H 9.08%. In terms of performance, its good thermal stability, typical liquid crystal texture, wide liquid crystal phase transition range, and mesocrystalline intermediate phase stacking mode were tested using a polarizing microscope with a hot stage (POM), differential scanning calorimetry (DSC), and small-angle / wide-angle X-ray scattering (S / WAXS) techniques. Furthermore, its photoelectric properties, including ultraviolet-visible absorption spectroscopy, fluorescence emission spectroscopy, and fluorescence quantum yield, were also tested.

[0048] Example 7: Synthesis of the target compound Py-Ph2-TP6 (pyrene-biphenyl-benzophenanthrene tetrad compound) A method for preparing the pyrene-biphenyl-benzophenanthrene tetrameric compound Py-Ph2-TP6, the synthesis steps of which are as follows: Under argon protection, Py-4Bpin (88.2 mg, 0.12 mmol), TP6-Ph2-Br (600.0 mg, 0.62 mmol), K2CO3 (345.44 mg, 2.50 mmol), and Pd(PPh3)4 (43.3 mg, 0.04 mmol) were mixed in a THF / H2O (9.0 mmol / L) atmosphere. The mixture was stirred in a solvent mixture of 1 mL / 3.0 mL; the mixture was heated to 70 °C under stirring and reacted for 48 hours; after cooling, the mixture was extracted with CH2Cl2, dried with MgSO4, and the solvent was removed under vacuum; the residue was eluted by silica gel column chromatography (petroleum ether / CH2Cl2, 1 / 1.5, v / v); recrystallization from ethyl acetate and ethanol gave a bright yellow solid Py-Ph2-TP6 (317.0 mg, 68%); in this example, the structure of the target compound Py-Ph2-TP6 was identified by 1H NMR, 1C NMR, high-resolution mass spectrometry, and elemental analysis. 1 H NMR (CDCl3, TMS, 600MHz) δ (ppm): 8.46 (s, 4H), 8.40 (s,4H), 8.22 (s, 2H), 7.97-7.85 (m, 52H), 4.28-4.27 (m, 40H), 1.97-1.89 (m,40H), 1.61-1.56 (m, 40H), 1.42-1.39 (m, 80H), 0.97-0.92 (m, 60H). 13 C NMR (CDCl3, 151 MHz) δ (ppm): 148.82, 140.02, 139.37, 138.09, 137.01, 131.23,130.44, 129.62, 128.26, 127.12, 126.74, 126.18, 125.49, 123.10, 106.98,104.94, 69.86, 69.50, 69.38, 68.76, 31.71, 31.70, 31.66, 31.54, 29.46, 29.41,29.38, 29.23, 25.91, 25.88, 25.85, 25.82, 22.67, 22.64, 14.06. HRMS (MALDI):[M] + calcd for C 256 H 322 O 20, m / z: 3718.4247 (100.0%), 3719.4280 (77.9%), 3717.4213 (72.5%), 3720.4314 (46.3%), 3716.4180 (26.2%); found, 3718.4239,3719.4289, 3717.4190, 3720.4304, 3716.4204. Elemental analysis: calculated for C 256 H 322 O 20 (3719.37), C 82.67%, H 8.73%; found, C 82.56%, H 8.60%. In terms of performance, its good thermal stability, typical liquid crystal texture, wide liquid crystal phase transition range, and mesocrystalline intermediate phase stacking mode were tested using a polarizing microscope with a hot stage (POM), differential scanning calorimetry (DSC), and small-angle / wide-angle X-ray scattering (S / WAXS) techniques. Furthermore, its photoelectric properties, including ultraviolet-visible absorption spectroscopy, fluorescence emission spectroscopy, and fluorescence quantum yield, were also tested.

Claims

1. An X-type rigid-bridged pyrene-benzophenanthrene tetrameric disk-shaped liquid crystal compound, characterized in that, The X-type rigid-bridged pyrene-benzophenanthrene tetrameric disk-shaped liquid crystal compound has the structure of Formula I, where Ar represents a σ single bond, a benzene ring, or a biphenyl, and R is an alkyl chain -C6H. 13 。 2. A method for preparing the X-type pyrene-benzophenanthrene tetrameric disc-shaped liquid crystal compound Py-TP6, characterized in that... Includes the following steps: Step 1: Preparation of intermediate Py-4Bpin: At 120 °C, Br2 was added dropwise to a stirred nitrobenzene solution of pyrene in a molar ratio of 1:4.

4. The mixture was kept at 120 °C for 5 hours and then cooled to room temperature. The reaction mixture was filtered, and the residue was washed with methanol and acetone. After drying under reduced pressure, a pale yellow solid, Py-4Br, was obtained, which was insoluble in all common organic solvents at room temperature. Immediately afterwards, 1,3,6,8-tetrabromopyrene Py-4Br:B2Pin2:CH3COOK:Pd(dppf)Cl2·CH2Cl2 in a molar ratio of 1:6:12:2 was weighed and added to a dry polytetrafluoroethylene-sealed Schlenk tube under an argon atmosphere. After the addition of 1,4-dioxane, the reaction was subjected to three freeze-thaw cycles to remove trace amounts of oxygen, and then at 90 °C. The reaction was stirred at ℃ for 24 hours; after the reaction was completed, the reaction mixture was cooled to room temperature and washed with salt water solution; the organic layer was dried with anhydrous MgSO4, evaporated, and the residue was purified by column chromatography using CH2Cl2 as eluent to obtain a light yellow powder Py-4Bpin. Step 2: Preparation of the X-type pyrene-benzophenanthrene tetrad disk-shaped liquid crystal compound Py-TP6: Under argon protection, a mixture of Py-4Bpin:TP6-Br:K2CO3:Pd(PPh3)4 in a molar ratio of 1:5:20:0.3 was weighed and stirred in a THF / H2O (volume ratio THF:H2O=3:1) solvent. The mixture was heated to 70°C and reacted for 48 hours with stirring. After cooling, the mixture was extracted with CH2Cl2, dried with MgSO4, and the solvent was removed under vacuum. The residue was eluted by silica gel column chromatography (petroleum ether / CH2Cl2, 4 / 1, v / v). Recrystallization from ethyl acetate and ethanol yielded a bright yellow solid, Py-TP6.

3. A method for preparing X-type pyrene-Ar-benzophenanthrene tetrameric disc-shaped liquid crystal compounds Py-Ph-TP6 / Py-Ph2-TP6, characterized in that... Includes the following steps: Step 1: Preparation of intermediate Py-4Bpin: At 120 °C, Br2 was added dropwise to a stirred nitrobenzene solution of pyrene in a molar ratio of 1:4.

4. The mixture was kept at 120 °C for 5 hours and then cooled to room temperature. The reaction mixture was filtered, and the residue was washed with methanol and acetone. After drying under reduced pressure, a pale yellow solid, Py-4Br, was obtained, which was insoluble in all common organic solvents at room temperature. Immediately afterwards, 1,3,6,8-tetrabromopyrene Py-4Br:B2Pin2:CH3COOK:Pd(dppf)Cl2·CH2Cl2 in a molar ratio of 1:6:12:2 was weighed and added to a dry polytetrafluoroethylene-sealed Schlenk tube under an argon atmosphere. After the addition of 1,4-dioxane, the reaction was subjected to three freeze-thaw cycles to remove trace amounts of oxygen, and then at 90 °C. The reaction was stirred at ℃ for 24 hours; after the reaction was completed, the reaction mixture was cooled to room temperature and washed with salt water solution; the organic layer was dried with anhydrous MgSO4, evaporated, and the residue was purified by column chromatography using CH2Cl2 as eluent to obtain a light yellow powder Py-4Bpin. Step 2: Preparation of intermediate TP6-Bpin: Under an argon atmosphere, TP6-Br:B2Pin2:Pd(dppf)Cl2·CH2Cl2:CH3COOK were weighed and added to a dry flask in a molar ratio of 1:2.2:0.05:

3. After adding 1,4-dioxane, the reaction mixture was stirred at 90 °C for 24 hours. Then, the reaction mixture was cooled to room temperature and extracted with CH2Cl2. The combined organic layers were dried over anhydrous MgSO4, evaporated, and the residue was purified by column chromatography (elution: petroleum ether / CH2Cl2, 1 / 3, v / v). Recrystallization from ethyl acetate and ethanol yielded a white solid, TP6-Bpin. Step 3: Preparation of intermediates TP6-Ph-Br / TP6-Ph2-Br: Under argon protection, TP6-Bpin:1-bromo-4-iodobenzene or 4-bromo-4'-iodo-1,1'-biphenyl:K2CO3:Pd(PPh3)4 = 1:1.5:5:0.1 was weighed and added to a Schlenk reaction tube; then a degassed mixed solvent with a volume ratio of THF:H2O = 2:1 was added; the mixture was stirred at 70 °C for 24 hours; then cooled, extracted with CH2Cl2 and dried over MgSO4; the organic solvent was removed by distillation, and the residue was purified by silica gel column chromatography (petroleum ether / CH2Cl2, 3 / 1 or 1.5 / 1, v / v); recrystallized from ethyl acetate and ethanol to give TP6-Ph-Br or TP6-Ph2-Br as a white solid. Step 4: Preparation of X-type pyrene-Ar-benzophenanthrene tetrameric disc-shaped liquid crystal compounds Py-Ph-TP6 / Py-Ph2-TP6: Under argon protection, Py-4Bpin:TP6-Ph-Br or TP6-Ph2-Br:K2CO3:Pd(PPh3)4 in a molar ratio of 1:5:20:0.3 was weighed and stirred in a THF / H2O mixed solvent (volume ratio THF:H2O=3:1). The mixture was heated to 70°C and reacted for 48 hours with stirring. After cooling, the mixture was extracted with CH2Cl2, dried with MgSO4, and the solvent was removed under vacuum. The residue was eluted by silica gel column chromatography (petroleum ether / CH2Cl2, 1 / 1.5, v / v). Recrystallization from ethyl acetate and ethanol yielded a bright yellow solid, Py-Ph-TP6 or Py-Ph2-TP6.

4. The use of the X-type quadruple disk-shaped liquid crystal target compounds Py-TP6, Py-Ph-TP6 and Py-Ph2-TP6 as organic liquid crystal materials, liquid crystal semiconductor materials and their composite materials in organic thin film electronic devices.

5. Without departing from the concept of the present invention, those skilled in the art can make improvements to the preparation method and the instruments used within the scope of the claims, and such improvements should also be considered within the scope of protection of the present invention.

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