Spirofluorene xanthene compound and application thereof
By designing spirofluorene-xanthracene compounds as electron transport materials for OLEDs, the problem of insufficient electron transport performance was solved, achieving high efficiency and long lifespan of the device while reducing the driving voltage.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- FUYANG SINEVA MATERIAL TECHNOLOGY CO LTD
- Filing Date
- 2026-02-13
- Publication Date
- 2026-06-16
AI Technical Summary
Existing OLED electron transport materials have insufficient electron transport performance, which limits the luminous efficiency, lifespan, and operating voltage of the devices.
Spirofluorene-xanthracene compounds were used as electron transport materials. By optimizing their molecular structure design, electron transport performance was enhanced and the energy barrier during electron injection and transport was reduced.
This improved the luminous efficiency of OLED light-emitting devices, reduced the driving voltage, and extended the device's lifespan.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of organic electroluminescent materials, specifically relating to a spirofluoreneoxane compound and its applications. Background Technology
[0002] OLED (Organic Light-Emitting Diode) is an electroluminescent technology based on organic materials. Its core principle is that under an applied electric field, electrons and holes in the organic semiconductor material are injected from the cathode and anode, respectively, and recombine in the light-emitting layer to form excitons. When these excitons de-excite, they release energy, thus producing visible light. Compared to traditional liquid crystal displays (LCDs), OLEDs offer advantages such as self-illumination, high contrast, wide viewing angle, fast response time, and flexibility, making them widely used in high-end smartphones, televisions, wearable devices, and other display applications.
[0003] Organic electroluminescence (EL) devices are semiconductor devices that directly convert electrical energy into light energy, with their core light-emitting materials being small organic molecules or polymers. The structure of an organic electroluminescence device specifically consists of an anode, a cathode, and an organic layer between them. To improve the efficiency and stability of organic electroluminescence elements, the organic layer comprises multiple layers with different materials, such as a hole injection layer (HIL), a hole transport layer (HTL), a hole blocking layer, a light-emitting layer, an electron transport layer (ETL), and an electron injection layer (EIL).
[0004] Currently, organic electroluminescence has become the mainstream display technology, and correspondingly, various novel OLED materials have been developed. The electron transport performance of electron transport materials is a major obstacle to the widespread practical application of OLED technology, directly limiting the device's luminous efficiency, lifespan, and operating voltage. Therefore, to meet the higher demands for OLED devices, there is an urgent need in this field to develop more diverse and higher-performance OLED electron transport materials. Summary of the Invention
[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a spirofluoreneoxane compound and its application. As an electron transport material for OLED light-emitting devices, the spirofluoreneoxane compound can enable OLED light-emitting devices to have lower driving voltage, higher current efficiency and longer lifespan.
[0006] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a spirofluorene xanthracene compound having the structure shown in Formula I:
[0007] Formula I Among them, X1, X2, and X3 are each independently selected from N or CH, and at least one of X1, X2, and X3 is selected from N; R1 is selected from any one of H, substituted or unsubstituted C6~C60 aryl, substituted or unsubstituted C3~C60 heteroaryl; R2 is selected from any one of substituted or unsubstituted C6~C60 arylene or substituted or unsubstituted C3~C60 heteroarylene; In R1 and R2, each of the substituents is independently selected from at least one of cyano, C6-C60 aryl, and C3-C60 heteroaryl. L is selected from phenylene or naphthylene; n is selected from 0 or 1; In the compound of formula I, each hydrogen atom can be independently replaced by at least one of deuterium atom or phenyl atom.
[0008] This invention, through the design of compound structures, yields spirofluoreneoxanthracene compounds with unique molecular structures that significantly enhance the electron transport performance of devices and effectively reduce the energy barrier during electron injection and transport. This property helps to lower the operating voltage of OLED light-emitting devices, improve luminous efficiency, and thus exhibit excellent luminescent performance. These compounds are suitable for the fabrication of OLED light-emitting devices, especially as electron transport materials, and can further reduce the driving voltage and improve current efficiency while maintaining a high device lifetime, which is beneficial for the fabrication of high-performance OLED light-emitting devices.
[0009] Preferably, two or more of X1, X2, and X3 are selected from N.
[0010] Preferably, any two of X1, X2, and X3 are selected from N, and the other is selected from CH.
[0011] Preferably, X1, X2, and X3 are all selected from N.
[0012] Preferably, in R1, the C6~C60 aryl group is selected from any one of phenyl, naphthyl, biphenyl, and terphenyl, and the C3~C60 heteroaryl group is selected from any one of pyridyl, dibenzofuranyl, and dibenzothiazolyl.
[0013] Preferably, in R2, the C6~C60 arylene groups are selected from any one of phenylene, naphthylene, biphenylene, terphenylene, and phenanthrene, and the C3~C60 heteroarylene groups are selected from any one of pyridylene, dibenzofuranylene, and dibenzothiazolylene.
[0014] Preferably, in R1 and R2, the substituents are each independently selected from at least one of cyano, phenyl, naphthyl, biphenyl, terphenyl, pyridyl, N-carbazole, dibenzofuranyl, and dibenzothiazolyl.
[0015] Preferably, the spirofluorenexanthracene compound is selected from any one of the following compounds, whether substituted or unsubstituted:
[0016]
[0017]
[0018]
[0019]
[0020]
[0021]
[0022]
[0023]
[0024]
[0025]
[0026]
[0027] The substitution refers to the fact that each hydrogen atom in the above compound can be independently replaced by a deuterium atom.
[0028] Preferably, the spirofluorenexanthracene compound is selected from any one of the following compounds 1 to 4, whether substituted or unsubstituted: , , , ; The substitution refers to the fact that each hydrogen atom in compounds 1 to 4 can be independently replaced by a deuterium atom.
[0029] Secondly, the present invention provides the application of spirofluoreneoxane compounds as described in the first aspect as electron transport materials for organic electroluminescent devices.
[0030] Thirdly, the present invention provides an organic electroluminescent device, the organic electroluminescent device comprising the spirofluorene-xanthracene compound as described in the first aspect.
[0031] Preferably, the organic electroluminescent device includes an anode, a cathode, and an organic thin film layer disposed between the anode and the cathode, wherein the organic thin film layer includes the spirofluorenexanthracene compound.
[0032] Preferably, the organic thin film layer includes an electron transport layer, which includes the spirofluorenexanthracene compound.
[0033] In this invention, the organic thin film layer includes a light-emitting layer, which comprises a host material and a dopant material. This invention does not impose any special limitations on the host material and dopant material of the light-emitting layer; any host material and dopant material known in the art can be used.
[0034] Preferably, the organic thin film layer further includes one or a combination of several of the following: a hole injection layer, a hole transport layer, and an electron injection layer. In this invention, no special restrictions are placed on the materials used for the hole injection layer, hole transport layer, and electron injection layer; any materials known in the art capable of hole injection, hole transport, electron transport, and electron injection can be used.
[0035] Fourthly, the present invention provides a display device comprising the organic electroluminescent device as described in the third aspect.
[0036] Compared with the prior art, the present invention has the following beneficial effects: This invention, through the design of compound structures, yields spirofluoreneoxane compounds suitable as electron transport materials for OLED light-emitting devices, enabling OLED light-emitting devices to have lower driving voltage, higher current efficiency, and longer lifespan. Detailed Implementation
[0037] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.
[0038] Synthesis Example 1 This synthetic example provides a method for preparing compound 1, the specific preparation method of which is as follows:
[0039] Under nitrogen protection, 50 ml of toluene, 5 g of the boron ester compound shown in P1-1, 1.43 g of 2-bromoquinoline, 2.02 g of potassium acetate, and 0.23 g of dichlorodi-tert-butyl-(4-dimethylaminophenyl)phosphine palladium(II) were added sequentially to a reaction flask. The mixture was slowly heated to 105 °C and reacted for 4.5 h. After the reaction was completed, the mixture was cooled to room temperature, and 100 ml of anhydrous ethanol was added and stirred for 30 min. The precipitated solid was filtered, washed sequentially with water and methanol, dried, and then separated by silica gel column chromatography to obtain 4.0 g of compound 1.
[0040] The mass-to-charge ratio (m / z) of compound 1 was measured to be 766.27 by mass spectrometry.
[0041] Synthesis Example 2
[0042] Synthesis of intermediate P2-2 Under nitrogen protection, 80 ml of toluene, 4.3 g of the boron ester compound shown in P2-1, 1.9 g of 1-chloro-4-bromodibenzofuran, 2.12 g of potassium carbonate, and 0.19 g of dichlorodi-tert-butyl-(4-dimethylaminophenyl)phosphine palladium(II) were added sequentially to a reaction flask. The mixture was slowly heated to 105 °C and reacted for 5 h. After the reaction was completed, the mixture was cooled to room temperature, and 80 ml of anhydrous ethanol was added and stirred for 30 min. The precipitated solid was filtered, washed sequentially with water and methanol, dried, and separated by silica gel column chromatography to obtain 3.1 g of intermediate P2-2.
[0043] The intermediate P2-2 was detected by mass spectrometry, and the m / z was 687.17.
[0044] Synthesis of Compound 2 Under nitrogen protection, 110 ml of toluene, 5 g of intermediate P2-2, 1.93 g of 2-quinoline pinacol ester, 2.32 g of potassium acetate, and 0.23 g of [1,1'-bis(diphenylphosphine)ferrocene]palladium(II) dichloride were added sequentially to a reaction flask. The mixture was slowly heated to 105 °C and reacted for 12 h. After the reaction was completed, the mixture was cooled to room temperature, and 100 ml of anhydrous ethanol was added and stirred for 30 min. The precipitated solid was filtered, washed successively with water and methanol, dried, and separated by silica gel column chromatography to obtain 3.9 g of compound 2.
[0045] Compound 2 was detected by mass spectrometry, and the m / z was 780.25.
[0046] Synthesis Example 3
[0047] Following the preparation method of compound 1 in Synthesis Example 1, except that the boron ester compound shown in P1-1 was replaced with an equimolar amount of the boron ester compound shown in P3-1, and other conditions remained unchanged, compound 3 was prepared.
[0048] Compound 3 was analyzed by mass spectrometry and the m / z was measured to be 691.24.
[0049] Synthesis Example 4
[0050] Synthesis of intermediate P4-2 The preparation method of intermediate P2-2 in Synthesis Example 2 is the same, except that 1-chloro-4-bromodibenzofuran is replaced with an equimolar amount Under the same conditions, intermediate P4-2 was prepared.
[0051] The intermediate P4-2 was detected by mass spectrometry, and the m / z was 762.22.
[0052] Synthesis of Compound 4 Following the preparation method of compound 2 in Synthesis Example 2, except that intermediate P2-2 was replaced with an equimolar amount of intermediate P4-2, and other conditions remained unchanged, compound 4 was prepared.
[0053] Compound 4 was detected by mass spectrometry, and the m / z was 855.30.
[0054] Other compounds for which specific synthesis steps are not listed can be prepared using common knowledge in the art, in conjunction with the above examples.
[0055] The specific structures of several materials used in the device embodiments and comparative examples of the present invention are as follows:
[0056] The synthesis of compound D3:
[0057] The preparation method of compound 1 in Synthetic Example 1 is the same, except that 2-bromoquinoline is replaced with an equimolar amount Under the same conditions, compound D3 was prepared.
[0058] The mass-to-charge ratio (m / z) of compound D3 was measured to be 766.27 by mass spectrometry.
[0059] The synthesis of compound D4:
[0060] The preparation method of compound 1 in Synthetic Example 1 is the same, except that 2-bromoquinoline is replaced with an equimolar amount Under the same conditions, compound D4 was prepared.
[0061] The mass-to-charge ratio (m / z) of compound D4 was measured to be 766.27 by mass spectrometry.
[0062] Device Example 1 This embodiment of the device provides an organic electroluminescent device with the following structure: ITO / HIL02 (100nm) / HT (40nm) / BH:D-4 3% (30nm) / Compound 1 (30nm) / LiF (0.5nm) / Al (150nm).
[0063] The fabrication method of organic electroluminescent devices is as follows: The material was placed inside a vacuum chamber, and the vacuum was evacuated to 1×10⁻⁶. -5 ~1×10 -6 Pa is sequentially vacuum-deposited onto the cleaned ITO substrate.
[0064] HIL02 (100nm) is a hole injection layer with a thickness of 100nm; HT (40nm) is the hole transport layer with a thickness of 40nm; BH:D-4 3% (30nm) is the light-emitting layer. BH:D-4 3% refers to the doping ratio of the doped material in the light-emitting layer. That is, the volume ratio of the main material BH to the doped material D-4 in the light-emitting layer is 97:3, and the thickness of the light-emitting layer is 30nm. Compound 1 (30 nm) is an electron transport layer, which is composed of compound 1 and has a thickness of 30 nm.
[0065] The LiF (0.5nm) layer is an electron-injection layer with a thickness of 0.5nm.
[0066] ITO refers to the anode, and Al (150nm) refers to the cathode.
[0067] Device Examples 2-4 Device Examples 2-4 each provide an organic electroluminescent device. The only difference between them and Device Example 1 is that the electron transport layer material is different. For details of the specific materials, please refer to Table 1 below. Other conditions are the same as those in Device Example 1.
[0068] Device Comparison Examples 1-4 Comparative Examples 1 to 4 each provide an organic electroluminescent device, which differs from Device Example 1 only in that the electron transport layer material is different. The specific materials are detailed in Table 1 below, and other conditions are the same as those in Device Example 1.
[0069] Performance testing The luminance, driving voltage, current efficiency, and LT95 of the organic electroluminescent devices provided above were tested. The voltage and current efficiency are calculated based on a luminance of 1000 cd / m². 2 The corresponding value, LT95, refers to maintaining an initial device current density of 10 mA / cm². 2 The time required for the device efficiency to drop to 95% of the efficiency corresponding to the initial current density is constant, where voltage, current efficiency, and LT95 are relative values (based on device comparison example 1). Specific test results are shown in Table 1.
[0070] Table 1
[0071] As shown in Table 1, the spirofluoreneoxanthracene compounds obtained by this invention through the design of compound structures can increase the electron transport capability of devices, reduce the electron injection transport barrier, lower the driving voltage, and thus improve the luminous efficiency of devices. These compounds are suitable for the fabrication of OLED light-emitting devices, and are particularly suitable as electron transport materials, enabling OLED light-emitting devices to have lower driving voltage, higher current efficiency, and longer lifetime.
[0072] The present invention has been illustrated with the above embodiments to describe the detailed process flow of the present invention. However, the present invention is not limited to the above detailed process flow, that is, it does not mean that the present invention must rely on the above detailed process flow to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.
Claims
1. A spirofluorene-xanthracene compound, characterized in that, The spirofluorene xanthracene compound has the structure shown in Formula I: ； Formula I Among them, X1, X2, and X3 are each independently selected from N or CH, and at least one of X1, X2, and X3 is selected from N; R1 is selected from any one of H, substituted or unsubstituted C6~C60 aryl, substituted or unsubstituted C3~C60 heteroaryl; R2 is selected from any one of substituted or unsubstituted C6~C60 arylene or substituted or unsubstituted C3~C60 heteroarylene; In R1 and R2, each of the substituents is independently selected from at least one of cyano, C6-C60 aryl, and C3-C60 heteroaryl. L is selected from phenylene or naphthylene; n is selected from 0 or 1; In the compound of formula I, each hydrogen atom can be independently replaced by at least one of deuterium atom or phenyl atom.
2. The spirofluorene-xanthracene compound according to claim 1, characterized in that, Two or more of X1, X2, and X3 are selected from N; Preferably, any two of X1, X2, and X3 are selected from N, and the other is selected from CH; Preferably, X1, X2, and X3 are all selected from N.
3. The spirofluorene-xanthracene compound according to claim 1, characterized in that, In R1, the C6~C60 aryl group is selected from any one of phenyl, naphthyl, biphenyl, and terphenyl, and the C3~C60 heteroaryl group is selected from any one of pyridyl, dibenzofuranyl, and dibenzothiazolyl. Preferably, in R2, the C6~C60 arylene groups are selected from any one of phenylene, naphthylene, biphenylene, terphenylene, and phenanthrene, and the C3~C60 heteroarylene groups are selected from any one of pyridylene, dibenzofuranylene, and dibenzothiazolylene.
4. The spirofluorene-xanthracene compound according to claim 1, characterized in that, In R1 and R2, the substituents are each independently selected from at least one of cyano, phenyl, naphthyl, biphenyl, terphenyl, pyridyl, N-carbazole, dibenzofuranyl, and dibenzothiazolyl.
5. The spirofluorene-xanthracene compound according to claim 1, characterized in that, The spirofluorene xanthracene compound is selected from any one of the following compounds, whether substituted or unsubstituted: ； ； ； ； ； ； ； ； ； ； ； ； The substitution refers to the fact that each hydrogen atom in the above compound can be independently replaced by a deuterium atom.
6. The spirofluorene-xanthracene compound according to claim 1, characterized in that, The spirofluorene xanthracene compound is selected from any one of the following compounds 1 to 4, whether substituted or unsubstituted: 、 、 、 ； The substitution refers to the fact that each hydrogen atom in compounds 1 to 4 can be independently replaced by a deuterium atom.
7. The application of the spirofluoreneoxane compounds as described in any one of claims 1 to 6 as electron transport materials for organic electroluminescent devices.
8. An organic electroluminescent device, characterized in that, The organic electroluminescent device includes the spirofluorene-xanthracene compound as described in any one of claims 1 to 6.
9. The organic electroluminescent device according to claim 8, characterized in that, The organic electroluminescent device includes an anode, a cathode, and an organic thin film layer disposed between the anode and the cathode, wherein the organic thin film layer includes the spirofluoreneoxane compound.
10. The organic electroluminescent device according to claim 9, characterized in that, The organic thin film layer includes an electron transport layer, which includes the spirofluorene-xanthracene compound.