A compound of a binaphthyl structure, and a preparation method and application thereof

Abstract

This invention provides a p-dinaphthalene-structured compound, its preparation method, and its applications, belonging to the field of organic electroluminescence technology. The p-dinaphthalene-structured compound provided by this invention has the structural formula shown in Formula 1, wherein R1 is selected from substituted or unsubstituted boron-nitrogen heterocyclic groups, oxynitrogen heterocyclic groups, sulfur-nitrogen heterocyclic groups, oxysulfur-nitrogen heterocyclic groups, oxyboron-nitrogen heterocyclic groups, sulfur-boron-nitrogen heterocyclic groups, and selenium-boron-nitrogen heterocyclic groups. The p-dinaphthalene-structured compound provided by this invention has chiral enantiomeric structural characteristics, and electroluminescent devices prepared using it have the advantages of circularly polarized emission, high external quantum efficiency, and high stability.

Description

Technical Field

[0001] This invention belongs to the field of organic electroluminescence technology, and particularly relates to a naphthalene-structured compound, its preparation method, and its application. Background Technology

[0002] As OLED display technology matures, the application of various light-emitting materials has undergone a process of continuous innovation and reform. Significant efforts have been made in developing materials suitable for organic light-emitting devices (OLEDs). These devices are commercially attractive because they promise to manufacture high-density pixelated displays at low cost, featuring bright electroluminescence, long lifespan, and a wide color gamut.

[0003] A typical OLED is fabricated by sandwiching an emitter layer between an anode and a cathode. When a bias voltage is applied to the electrodes, holes and electrons are injected into the emitter layer from the anode and cathode, respectively, typically facilitated by hole transport and electron transport layers (transport layers adjacent to the respective electrodes). Holes and electrons radiatively combine in the emitter layer and emit light. Performance can be improved by providing a barrier layer to prevent the injection of holes or electrons from adjacent layers and their subsequent escape from the device. Some of these layers can be combined. For example, a bilayer structure is made of a combination of hole injection and transport layers and a combination of electron transport and emission layers. Similarly, a trilayer structure consists of a hole injection and transport layer, an emission layer, and an electron injection and transport layer.

[0004] In addition, these layers can be formed from a host material doped with another material to achieve the desired effect of the layer, such as hole transport effect, electron transport effect, or emission effect.

[0005] Because consumers expect high efficiency, long service life and pure color, it is necessary to develop suitable materials for each layer. Summary of the Invention

[0006] In view of this, the purpose of this invention is to provide a p-dinaphthalene structure compound, its preparation method, and its application. The p-dinaphthalene structure compound provided by this invention, when applied to organic electroluminescent devices, can reduce the driving voltage of OLED devices, improve the luminous efficiency, color purity, and lifespan of the devices, and has significant application and commercial value in OLED devices, possessing promising industrialization prospects.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a p-dinaphthalene-structured compound having the structural formula shown in Formula 1: R1 is selected from substituted or unsubstituted boron-nitrogen heterocyclic groups, oxygen-nitrogen heterocyclic groups, sulfur-nitrogen heterocyclic groups, oxygen-sulfur-nitrogen heterocyclic groups, oxygen-boron-nitrogen heterocyclic groups, sulfur-boron-nitrogen heterocyclic groups, and selenium-boron-nitrogen heterocyclic groups.

[0008] Preferably, the p-naphthyl compound is selected from any one of the following structural formulas: .

[0009] This invention also provides a method for preparing the above-mentioned diphenylfluorene compound, comprising: reacting raw material 1 via a Suzuki coupling reaction to generate the diphenylfluorene compound shown in Formula 1; the synthetic route of the preparation method is as follows:

[0010] The present invention also provides an organic electroluminescent device, comprising an anode, a cathode, and an organic layer; the organic layer comprising the above-described p-naphthalene structure compound.

[0011] Preferably, the organic electroluminescent device is used in the fabrication of organic light-emitting diodes, organic photovoltaic cells, organic light-emitting cells, organic field-effect transistors, organic light-emitting field-effect transistors, organic lasers, organic spintronic devices, organic sensors, and organic plasma-emitting diodes.

[0012] The OLED devices using dinaphthalene-structured compounds provided by this invention generally have long operating life, low driving voltage, and improved current luminous efficiency.

[0013] The p-naphthalene structure compound described in this invention, when applied to organic electroluminescent devices, can reduce the driving voltage of OLED devices and improve the luminous efficiency, color purity, and lifespan of the devices. It has great application and commercial value in OLED devices and has good industrialization prospects. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the organic electroluminescent device of the present invention. In the figure, 1 is a transparent substrate layer; 2 is a transparent anode electrode layer; 3 is a hole injection layer; 4 is a hole transport layer; 5 is a light-emitting layer; 6 is an electron transport layer; 7 is an electron injection layer; and 8 is a cathode reflective electrode layer. Detailed Implementation

[0015] This invention provides a p-dinaphthalene-structured compound having the structural formula shown in Formula 1: R1 is selected from substituted or unsubstituted boron-nitrogen heterocyclic groups, oxygen-nitrogen heterocyclic groups, sulfur-nitrogen heterocyclic groups, oxygen-sulfur-nitrogen heterocyclic groups, oxygen-boron-nitrogen heterocyclic groups, sulfur-boron-nitrogen heterocyclic groups, and selenium-boron-nitrogen heterocyclic groups.

[0016] This invention uses p-dinaphthalene as the chiral center, introduces cyano steric hindrance groups at the 1 and 1' positions of the phenyl group of the p-dinaphthalene structure compound, and connects multiple resonance units at the 4 and 4' positions of the phenyl group of the p-dinaphthalene structure compound.

[0017] In this invention, the p-naphthyl compound is selected from any one of the following structural formulas: .

[0018] In this invention, the preparation method of the above-mentioned diphenylfluorene compound includes: reacting raw material 1 via a Suzuki coupling reaction to generate the diphenylfluorene compound shown in Formula 1; the synthetic route of the preparation method is as follows: .

[0019] In this invention, the preferred method for preparing the dinaphthalene-structured compound includes: under nitrogen protection, in a three-necked flask, dissolving a mixture of raw material 1 (1 eq), raw material 2 (2.2 eq), Pd2(dba)3 (0.044 eq), X-phos (0.13 eq), and sodium tert-butoxide (6.6 eq) in toluene at room temperature, refluxing and stirring at 100 °C for 6 hours, quenching the reaction with water, extracting, and then obtaining product formula 1 by column chromatography.

[0020] The present invention also provides an organic electroluminescent device, comprising an anode, a cathode, and an organic layer; the organic layer comprising the above-described p-naphthalene structure compound.

[0021] In this invention, the organic electroluminescent device is used in the fabrication of organic light-emitting diodes, organic photovoltaic cells, organic light-emitting cells, organic field-effect transistors, organic light-emitting field-effect transistors, organic lasers, organic spintronic devices, organic sensors, and organic plasma-emitting diodes.

[0022] In this invention, the p-naphthalene-structured compound is used as a luminescent material in OLED lighting and OLED display panels, wherein the luminescent material is selected from one or more of red luminescent materials, green luminescent materials and blue luminescent materials.

[0023] In this invention, the p-naphthalene-structured compound can also be used as an electron transport layer, light-emitting layer, or hole transport layer material for OLED devices.

[0024] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0025] Example 1 The specific synthetic route for compound 1 with a dinaphthalene structure is as follows:

[0026] A method for preparing compounds with the 1 structure in dinaphthalene structures includes the following steps: Under nitrogen protection, in a 250 mL three-necked flask, a mixture of starting material 1 (0.42 g, 1 mmol), starting material 2-1 (1.02 g, 2.2 mmol), Pd2(dba)3 (0.04 g, 0.044 mmol), X-phos (0.06 g, 0.13 mmol), and sodium tert-butoxide (0.63 g, 6.6 mmol) was dissolved in 100 mL of toluene at room temperature. After stirring under reflux at 100 °C for 6 hours, the reaction was quenched with water, extracted with dichloromethane, dried over anhydrous CaSO4, and compound 1 was obtained by column chromatography. HPLC analysis showed that starting material 1 was completely removed, with an HPLC purity of 99.8% and a yield of 64%.

[0027] Elemental analysis: C 78 H 52 B2N6; Theoretical values: C, 85.56; H, 4.79; B, 1.97; N, 7.68; Measured values: C, 85.36; H, 4.89; B, 1.87; N, 7.88; HRMS(ESI) m / z(M+): Theoretical value: 1094.44; Measured value: 1094.14.

[0028] Example 2 The specific synthetic route for compound 7 with a dinaphthalene structure is as follows:

[0029] A method for preparing compounds with the 7 structure in dinaphthalene structures includes the following steps: Under nitrogen protection, in a 250 mL three-necked flask, starting material 1 (0.42 g, 1 mmol), starting material 2-7 (0.75 g, 2.2 mmol), Pd2(dba)3 (0.04 g, 0.044 mmol), X-phos (0.06 g, 0.13 mmol), and sodium tert-butoxide (0.63 g, 6.6 mmol) were dissolved in 100 mL of toluene at room temperature. After stirring under reflux at 100 °C for 6 hours, the reaction was quenched with water, extracted with dichloromethane, dried over anhydrous CaSO4, and compound 7 was obtained by column chromatography. HPLC analysis showed that starting material 1 was completely removed, the HPLC purity was 98%, and the yield was 60%.

[0030] Elemental analysis: C 58 H 32 O4N4; Theoretical values: C, 82.06; H, 3.80; O, 7.54; N, 6.60; Measured values: C, 82.16; H, 3.70; O, 7.64; N, 6.50; HRMS(ESI)m / z(M+): Theoretical value: 848.24; Measured value: 848.04.

[0031] Example 3 The specific synthetic route for compound 15 with a dinaphthalene structure is as follows:

[0032] A method for preparing compounds with a 15 structure in dinaphthalene structures includes the following steps: Under nitrogen protection, in a 250 mL three-necked flask, starting material 1 (0.42 g, 1 mmol), starting material 2-15 (0.94 g, 2.2 mmol), Pd2(dba)3 (0.04 g, 0.044 mmol), X-phos (0.06 g, 0.13 mmol), and sodium tert-butoxide (0.63 g, 6.6 mmol) were dissolved in 100 mL of toluene at room temperature. After stirring under reflux at 100 °C for 6 hours, the reaction was quenched with water, extracted with dichloromethane, dried over anhydrous CaSO4, and compound 15 was obtained by column chromatography. HPLC analysis showed that starting material 1 was completely removed, the HPLC purity was 99%, and the yield was 61%.

[0033] Elemental analysis: C 72 H 50 O2B2N4; Theoretical values: C, 84.38; H, 4.92; O, 3.12; B, 2.11; N, 5.47; Measured values: C, 84.48; H, 4.82; O, 3.32; B, 2.21; N, 5.37; HRMS(ESI) m / z(M+): Theoretical value: 1024.41; Measured value: 1024.11.

[0034] Example 4 The specific synthetic route for compound 38 with a dinaphthalene structure is as follows:

[0035] A method for preparing compounds with a 38 structure in dinaphthalene structures includes the following steps: Under nitrogen protection, in a 250 mL three-necked flask, starting material 1 (0.42 g, 1 mmol), starting material 2-38 (1.33 g, 2.2 mmol), Pd2(dba)3 (0.04 g, 0.044 mmol), X-phos (0.06 g, 0.13 mmol), and sodium tert-butoxide (0.63 g, 6.6 mmol) were dissolved in 100 mL of toluene at room temperature. After stirring under reflux at 100 °C for 6 hours, the reaction was quenched with water, extracted with dichloromethane, dried over anhydrous CaSO4, and compound 38 was obtained by column chromatography. HPLC analysis showed that starting material 1 was completely removed, the HPLC purity was 98.8%, and the yield was 65%.

[0036] Elemental analysis: C 94 H 76 B2N6S2; Theoretical values: C, 82.09; H, 5.57; B, 1.57; N, 6.11; S, 4.66; Measured values: C, 82.29; H, 5.67; B, 1.47; N, 6.21; S, 4.36; HRMS(ESI) m / z(M+): Theoretical value: 1375.58; Measured value: 1375.28.

[0037] Example 5 OLED light-emitting device structure as follows Figure 1 As shown, a hole injection layer (HIL) is deposited on a transparent conductive glass or plastic substrate, or on an indium tin oxide (ITO) substrate. Then, a hole transport layer (HTL), an emissive layer (EML), an electron transport layer (ETL), and an electron injection layer (EIL) are sequentially passed through. Finally, a metal layer is added as a conductive cathode and a sealing ring. This invention relates to a p-naphthalene-structured compound, a novel material with excellent electron and hole transport and light emission properties. The following example, using a novel p-naphthalene-structured compound as the emissive layer, illustrates the study of device performance.

[0038] The transparent anode electrode layer 2 (film thickness 209 nm, indium tin oxide) on the transparent substrate layer 1 is processed as follows: First, photolithography and etching are performed to form the required regular transparent anode electrode layer 2. Then, the transparent substrate layer 1 is washed sequentially, including alkaline washing, deionized water washing, acetone ultrasonic cleaning, ethanol ultrasonic cleaning, ultrapure water cleaning, and drying. Next, the transparent anode electrode layer 2 is subjected to ultraviolet-ozone washing to ensure the removal of organic residues on its surface. After the above washing process, a hole injection layer 3 is deposited on the transparent anode electrode layer 2 using a vacuum evaporation apparatus. The material shown in Formula 1 (molybdenum crucible, evaporation rate 0.1 nm / s, vacuum degree 4.0*10) is then deposited. -5 The organic material with a thickness of 56 nm (Pa) was deposited as hole injection layer 3. Immediately afterwards, a 24 nm thick material was deposited on hole injection layer 3 as hole transport layer 4. The material shown in Compound 1 was deposited onto hole transport layer 4 (molybdenum crucible, deposition rate 0.1 nm / s, vacuum degree 4.0 × 10⁻⁶). -5 Pa) yielded luminescent layer 5, with a film thickness of 31 nm.

[0039] Material is deposited on the light-emitting layer 5 to obtain the electron transport layer 6, with a film thickness of 79 nm. On the electron transport layer 6, a lithium fluoride (LiF) layer with a thickness of 0.8 nm is formed by vacuum evaporation to obtain the electron injection layer 7.

[0040] The cathode reflective electrode layer 8 is an aluminum (Al) layer with a thickness of 145 nm prepared on the electron injection layer 7 by vacuum evaporation.

[0041] Examples 6-14 The difference between Examples 6-14 and Example 5 is that the main material of the light-emitting layer of the electroluminescent device is compound 6, 10, 12, 17, 20, 25, 27, 30, 36 of the present invention.

[0042] Comparative Examples 1-3 The difference between Comparative Examples 1-3 and Example 5 is that the main material of the light-emitting layer of the electroluminescent device is compound α, β, γ. The structural formula is as follows:

[0043] The performance test data of the OLED devices in Examples 5-14 and Comparative Examples 1-3 are shown in Table 1: Table 1 OLED Device Performance Test Data

[0044] Note: The above OLED devices were tested with a forward DC voltage applied. The organic electroluminescence characteristics were measured using a PR-650 photometric instrument from Photo Research. The T95 lifetime was measured using a lifetime measurement device from McScience at a reference gray level of 5000 nits.

[0045] As can be seen from the test results in the table above, the OLED devices using the dinaphthalene structure compounds involved in this invention generally have longer operating lifetimes, lower driving voltages, and improved luminous efficiency compared to devices prepared using compounds α, β, or γ. Based on the inherent chirality of the dinaphthalene structure, a pair of blue-light boron-nitrogen heterocyclic enantiomers were obtained, and the electroluminescence asymmetry factor of the prepared semi-transparent CP-OLEDs reached 8.6 × 10⁻⁶. -3 The corresponding external quantum efficiency of the device is 17.8%, which is among the highest efficiency reported for semi-transparent OLEDs to date. In summary, this invention relates to OLED devices prepared from dinaphthalene-structured compounds, exhibiting excellent performance in all aspects.

[0046] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A compound with a p-naphthalene structure, characterized in that, The p-naphthalene-structured compound has the structural formula shown in Formula 1: R1 is selected from substituted or unsubstituted boron-nitrogen heterocyclic groups, oxygen-nitrogen heterocyclic groups, sulfur-nitrogen heterocyclic groups, oxygen-sulfur-nitrogen heterocyclic groups, oxygen-boron-nitrogen heterocyclic groups, sulfur-boron-nitrogen heterocyclic groups, and selenium-boron-nitrogen heterocyclic groups.

2. The p-naphthalene-structured compound according to claim 1, characterized in that, The p-naphthalene-structured compound is selected from any one of the following structural formulas: 。 3. The method for preparing a p-naphthalene-structured compound according to claim 1, characterized in that, The preparation method includes: reacting raw material 1 via a Suzuki coupling reaction to generate the diphenylfluorene compound shown in Formula 1 of claim 1; the synthetic route of the preparation method is as follows: 。 4. An organic electroluminescent device, characterized in that, It includes an anode, a cathode, and an organic layer; the organic layer includes the p-naphthalene structure compound as described in claim 1 or 2.

5. The application of the organic electroluminescent device according to claim 4 in the fabrication of organic light-emitting diodes, organic photovoltaic cells, organic light-emitting cells, organic field-effect transistors, organic light-emitting field-effect transistors, organic lasers, organic spintronic devices, organic sensors, and organic plasma-emitting diodes.

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