Polycyclic compound containing triphenyl silicon and polyalkyl substituent and organic electroluminescent device containing polycyclic compound

Abstract

The invention belongs to the technical field of OLEDs, and provides a polycyclic compound containing triphenyl silicon and a polyalkyl substituent group and an organic electroluminescent device containing the polycyclic compound. The structural general formula of the polycyclic compound is as shown in formula I in the specification. Benzofuran with higher electronegativity is introduced to a ring structure composed of nitrogen atoms and boron atoms, triphenyl silicon is introduced to the para-position of boron, and the synergistic effect of benzofuran and triphenyl silicon can significantly enhance the multiple resonance of a light-emitting core and reduce vibration relaxation. Due to simultaneous use of the benzofuran and the triphenyl silicon, the problems of vibration relaxation increase, spectrum widening and the like caused by introduction of the polyalkyl substituent are remarkably improved, the luminous efficiency of the material is remarkably improved, and the color purity is improved, so that the requirement of BT.2020 wide color gamut display standard on a luminescent spectrum is met. I

Description

Technical Field

[0001] This invention belongs to the field of OLED technology, specifically including a polycyclic compound containing triphenylsilane and polyalkyl substituents and an organic electroluminescent device containing the same. Background Technology

[0002] In the current OLED display field, the low efficiency and short lifespan of blue light-emitting devices remain key bottlenecks restricting the development of this field. Currently, mainstream OLED blue light technology still uses fluorescent light-emitting materials as the host material (BH) and dopant materials (BD). During the light emission process, the dopant material needs to obtain energy from the host material through a host-guest energy transfer mechanism. This process mainly relies on two forms: Förster energy transfer and Dexter energy transfer. Dexter energy transfer tends to cause the dopant material to generate long-lived triplet excitons during operation. Prolonged exposure to the excited state can lead to material decomposition; therefore, this energy transfer process should be suppressed as much as possible.

[0003] Since the rate constant of Dexter energy transfer is closely related to the intermolecular distance between the host and dopant materials, increasing the intermolecular distance can significantly reduce its probability. Therefore, existing dopants introduce a certain number of alkyl structures to increase the intermolecular distance. However, excessive alkyl structures significantly enhance vibrational relaxation in the excited state, leading to an increase in the full width at half maximum (FWHM) of the spectrum, which in turn reduces luminous efficiency. Furthermore, the FWHM of currently developed blue luminescent materials is already insufficient to fully meet the requirements of the BT.2020 wide color gamut standard; introducing excessive alkyl structures will exacerbate this problem.

[0004] Therefore, while suppressing Dexter energy transfer as much as possible, how to reduce vibrational relaxation to maintain high luminescence efficiency has become a core problem that urgently needs to be solved in the development of doped materials. Summary of the Invention

[0005] In view of this, the present invention provides a polycyclic compound containing triphenylsilane and polyalkyl substituents, and an organic electroluminescent device containing the same.

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: The first aspect of this invention provides a polycyclic compound containing triphenylsilane and polyalkyl substituents, the general structural formula of which is shown in Formula I: I; Wherein, R1 and R2 may be the same or different, and each independently represents any one of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl with C1 to C30 carbon atoms, substituted or unsubstituted cycloalkyl with C3 to C30 carbon atoms, substituted or unsubstituted aryl with C6 to C60 carbon atoms, substituted or unsubstituted heteroaryl with C5 to C60 carbon atoms, substituted or unsubstituted fused-ring aryl with C6 to C60 carbon atoms, and substituted or unsubstituted heterofused-ring aryl with C5 to C60 carbon atoms. Two or more R1 and R2 may be connected to each other to form an aliphatic ring, an aromatic ring, or a fused ring. Each time R appears, it independently represents any one of the following: a substituted or unsubstituted aryl group with C6 to C60 carbon atoms, a substituted or unsubstituted heteroaryl group with C5 to C60 carbon atoms, a substituted or unsubstituted fused-ring aryl group with C6 to C60 carbon atoms, or a substituted or unsubstituted heterofused-ring aryl group with C5 to C60 carbon atoms. m and n each independently represent 0, 1, 2, 3 or 4, preferably 0, 1 or 2; When R1, R2, and R contain substituents, the substituents are selected from alkyl groups having C1 to C10 carbon atoms or aryl groups having C6 to C20 carbon atoms; two or more of the substituents may be linked together to form an aliphatic ring; The polycyclic compound contains at least one 5 tert-butyl groups; or A ring structure consisting of three tert-butyl groups and one ring formed by connecting any two adjacent tert-butyl groups. Any hydrogen in Formula I can be substituted with deuterium or alkyl groups.

[0007] First, it should be noted that the following explains the substitution of hydrogen with tert-butyl groups and the cyclization in the structure: The substitution of at least one hydrogen atom with a tert-butyl group means that the hydrogen atoms in the structure can be substituted by one or more tert-butyl groups in the manner shown below. When there is more than one substituted tert-butyl group and two tert-butyl groups are adjacent, these two tert-butyl groups can lose two hydrogen atoms and connect to form a ring structure.

[0008]

[0009] Furthermore, R1 and R2 each independently represent any one of substituted or unsubstituted alkyl groups with C1 to C10 carbon atoms or substituted or unsubstituted aryl groups with C6 to C30 carbon atoms, wherein two or more R1 and R2 can be connected to each other to form an aliphatic ring.

[0010] Furthermore, each time R appears, it independently represents a substituted or unsubstituted aryl group with a carbon number of C6 to C20.

[0011] Furthermore, each time R appears, it independently represents any one of substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, or substituted or unsubstituted terphenyl.

[0012] Furthermore, each occurrence of R is represented independently. , , , , Any one of the above groups, where any hydrogen atom can be replaced by deuterium or alkyl.

[0013] Furthermore, the general structural formula of the polycyclic compound is shown in one of the following: I-1 I-2 I-3 I-4; R3 represents one of the following structures: , , , , , , , ; R4 represents one of the following structures: , , , , ; Any hydrogen in the above groups can be replaced by deuterium or tert-butyl, and at least one hydrogen in the above groups is replaced by tert-butyl. When more than one hydrogen is replaced, two adjacent tert-butyl groups can be linked to form a ring structure. “ " indicates a connection key.

[0014] Furthermore, R3 represents one of the following structures: , , , , ; and / or R4 represents one of the following structures: , , , , , .

[0015] Furthermore, R1 and R2 are represented independently. , , One of them; When R1 represents tert-butyl, two adjacent R1 positions can be connected to each other to form a ring structure; When R2 represents tert-butyl, two adjacent R2 positions can be connected to form a ring structure.

[0016] Furthermore, the polycyclic compound is selected from the structures shown below:

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064] .

[0065] A second aspect of the present invention provides an organic electroluminescent device, the organic electroluminescent device comprising an anode, a hole transport region, an emissive layer, an electron transport region and a cathode sequentially disposed on a substrate; wherein the emissive layer comprises a host material and a dopant material, the dopant material comprising one or more polycyclic compounds as described above.

[0066] Furthermore, the main material is selected from the following general structure: II; in, L is selected from single bonds or phenylene; Ar1 is selected from phenyl or naphthyl; Ar2 represents one of the following groups: , , , ; Any hydrogen atom in Formula II may be substituted with deuterium, alkyl, or aryl; “ " indicates a connection key.

[0067] Furthermore, the main material is selected from the structure shown below:

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074] .

[0075] Furthermore, the content of the main material in the light-emitting layer should be greater than 50 wt%, preferably greater than 90 wt%.

[0076] Furthermore, the content of doped material in the light-emitting layer should be less than 20 wt%, preferably less than 5 wt%.

[0077] Furthermore, the hole transport region includes at least one functional layer for transporting holes, such as a hole transport layer and a light-emitting auxiliary layer, wherein the materials used for the hole transport layer and the light-emitting auxiliary layer are selected from the following general structure: H-1; In this context, L1 independently represents a single bond, a phenylene group, or a biphenylene group; Ar3 can independently represent the following groups: , , , , , , , , ; In formula H-1, any one of the hydrogen atoms can be replaced by deuterium, alkyl, or aryl groups; “ " indicates a connection key.

[0078] Furthermore, the material used in the hole transport layer is selected from the following structures:

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087] .

[0088] Furthermore, the electron transport region includes at least one functional layer for electron transport, such as an electron transport layer or a hole blocking layer, wherein the materials used for the electron transport layer and the hole blocking layer are selected from the following general structure: H-2; L2 is selected from single bonds, phenylene, or biphenylene; Ar4 can independently represent the following groups: , , ; Ar5 represents the following groups: , , , , , , , ; Any hydrogen atom in formula H-2 can be replaced by deuterium, alkyl, or aryl groups; “ " indicates a connection key.

[0089] Furthermore, the material used in the electron transport layer is selected from the structure shown below:

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099] .

[0100] The beneficial effects of this invention are as follows: This invention provides a polycyclic compound containing triphenylsilane and polyalkyl substituents. By introducing a more electronegative benzofuran group into the ring structure composed of nitrogen and boron atoms, and simultaneously introducing triphenylsilane at the para-position of boron, the synergistic effect of benzofuran and triphenylsilane can significantly enhance the multiple resonances of the luminescent core and reduce vibrational relaxation. Therefore, the simultaneous use of benzofuran and triphenylsilane significantly improves the problems of increased vibrational relaxation and spectral broadening caused by the introduction of polyalkyl substituents, significantly improving the luminous efficiency and color purity of the material, and meeting the emission spectrum requirements of the BT.2020 wide color gamut display standard. Attached Figure Description

[0101] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0102] Figure 1 This is a schematic diagram of the structure of an organic electroluminescent device containing the compounds of the present invention; wherein, 1-substrate, 2-anode, 3-hole injection layer, 4-hole transport layer, 5-light-emitting auxiliary layer, 6-light-emitting layer, 7-hole blocking layer, 8-electron transport layer, 9-electron injection layer, 10-cathode, and 11-capping layer. Detailed Implementation

[0103] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments and accompanying drawings, further clarifies the invention. Similar components in the drawings are indicated by the same reference numerals. Those skilled in the art should understand that the specific description below is illustrative rather than restrictive and should not be construed as limiting the scope of protection of the present invention. The embodiments and comparative examples in this specification are provided to provide a more complete explanation of the specification to those skilled in the art. Various modifications can be made based on the embodiments and comparative examples in this specification, and the scope of protection of the present invention should not be limited to the embodiments and comparative examples detailed below.

[0104] The compounds of this invention are applicable to light-emitting elements, display panels, and electronic devices, particularly organic electroluminescent devices. The electronic devices of this invention are devices comprising a layer of at least one organic compound, and may also comprise layers of inorganic materials or layers formed entirely of inorganic materials. Preferred electronic devices include organic electroluminescent devices (OLEDs), organic integrated circuits (O-ICs), organic field-effect transistors (O-FETs), organic thin-film transistors (O-TFTs), organic light-emitting transistors (O-LETs), organic solar cells (O-SCs), organic dye-sensitized solar cells (O-DSSCs), organic optical detectors, organic photosensors, organic field quenching devices (O-FQDs), light-emitting electrochemical cells (LECs), organic laser diodes (O-lasers), and organic plasma emitting devices. Organic electroluminescent devices (OLEDs) are particularly preferred.

[0105] To better understand the present invention, the polycyclic compounds containing triarylamine structures, the preparation methods of the compounds, and the luminescent properties of the devices will be explained in detail with reference to embodiments. Various chemical reactions can be applied to the synthesis method of the compounds according to one embodiment of the present invention. However, it should be noted that the synthesis method of the compounds according to one embodiment of the present invention is not limited to the synthesis method described below. Unless otherwise stated, subsequent synthesis is carried out in an anhydrous solvent under a protective gas atmosphere. Solvents and reagents can be purchased from conventional reagent suppliers. The compounds of the present invention are prepared using representative reactions such as the Buchwald-Hartwig coupling reaction, the Suzuki coupling reaction, or the Heck coupling reaction.

[0106] Synthesis of intermediates

[0107] Sub1 (86.5 g), Sub2 (39.2 g), and sodium tert-butoxide (10.5 g) were added to toluene (500 ml). Then, under nitrogen protection, bis(dibenzyl) and palladium (2.7 g) and XantPhos (3.4 g) were added. The reaction system was then heated to reflux and maintained for 10 hours. After cooling to room temperature, the mixture was quenched with water and separated. The organic phase was filtered and dried with anhydrous sodium sulfate. The solvent was removed by rotary evaporation. The crude product was purified by column chromatography to finally obtain product Sub3: 85.8 g, MS (m / z) (M+): 962.

[0108] Sub3 (85.8 g), Sub4 (28.7 g), and sodium tert-butoxide (7.7 g) were added to toluene (500 ml). Then, under nitrogen protection, bis(dibenzyl) and palladium (2.0 g) and tri-tert-butylphosphine (0.9 g) were added. The reaction system was then heated to reflux and maintained for 10 hours. After cooling to room temperature, the mixture was quenched with water and separated. The organic phase was filtered and dried with anhydrous sodium sulfate. The solvent was removed by rotary evaporation. The crude product was purified by column chromatography, and the final product A1 was obtained: 79.3 g, MS (m / z) (M+): 1438.

[0109] The preparation of intermediates A2-A26 is carried out in accordance with the above process, and will not be repeated here.

[0110] Synthesis Example 1

[0111] The system was maintained at -30 to -40°C under nitrogen protection. A solution of n-butyllithium (15.40 mL) was slowly added dropwise to a solution of tert-butylbenzene (100 mL) containing compound A1 (14.38 g), followed by stirring at 60°C for 6 hours. Then, boron tribromide (1.91 mL) was added dropwise at -30°C, and the reaction system was stirred at 60°C for 6 hours. Finally, N,N-diisopropylethylamine (2.78 mL) was added at 0°C, and the reaction system was stirred at room temperature for 2 hours. 150 mL of deionized water was added to the reaction system to quench residual boron tribromide. The mixture was extracted three times with 200 mL of dichloromethane, the organic layers were combined, concentrated under vacuum, and purified by column chromatography with a mixed eluent of dichloromethane / petroleum ether (1:20). The crude product was recrystallized from n-heptane, acetone, and toluene to give product B1: 0.87 g, MS (m / z) (M+): 1380.

[0112] 1 H NMR (400 MHz, CDCl3) δ 8.16 (d, 1H), 7.60 – 7.52 (m, 4H), 7.49 –7.43 (m, 6H), 7.41 – 7.33 (m, 12H), 7.32 (d, 1H), 7.30 (s, 1H), 7.27 (d, 3H),7.14 (d, 1H), 7.08 (d, 2H), 7.01 – 6.95 (m, 3H), 1.54-1.49 (m, 12H), 1.35-1.30 (m, 9H), 1.29-1.25 (m, 18H), 0.91-0.87 (m, 36H).

[0113] Synthesis Example 2

[0114] The preparation method was the same as in Example 1, except that compound A2 (11.38 g) was used to replace compound A1, and the final product B2 was obtained: 0.74 g, MS (m / z) (M+): 1413.

[0115] 1H NMR (400 MHz, CDCl3) δ 8.60 (d, 1H), 7.64 (dd, 1H), 7.59 – 7.52 (m,5H), 7.52 – 7.43 (m, 9H), 7.41 – 7.33 (m, 13H), 7.31 (d, 4H), 7.27 (d, 2H),7.22 (dd, 1H), 7.08 (s, 1H), 7.00 (d, 2H), 1.74 (t, 8H), 1.32 (s, 9H), 1.20(s, 9H), 1.16-1.10 (m, 18H), 0.99-0.94 (m, 24H).

[0116] Synthesis Example 3

[0117] The preparation method was the same as in Example 1, except that compound A3 (14.62 g) was used to replace compound A1, and the final product B3 was obtained: 0.67 g, MS (m / z) (M+): 1391.

[0118] 1 H NMR (400 MHz, CDCl3) δ 8.16 (d, 1H), 7.59 – 7.51 (m, 6H), 7.45 (ddd, 7H), 7.41 – 7.33 (m, 13H), 7.31 (d, 4H), 7.27 (s, 2H), 7.25 – 7.16 (m,2H), 7.08 (s, 1H), 7.00 (d, 2H), 6.67 (dd, 1H), 1.61-1.58 (m, 8H), 1.39-1.33(m, 9H), 1.29 (s, 9H), 1.20-1.16 (m, 18H), 0.92-0.86 (m, 24H).

[0119] Synthesis Example 4

[0120] The preparation method was the same as in Synthesis Example 1, except that compound A4 (13.72 g) was used to replace compound A1, and the final product B4 was obtained: 0.80 g, MS (m / z) (M+): 1344.

[0121] 1H NMR (400 MHz, CDCl3) δ 8.16 (d, 1H), 7.60 – 7.51 (m, 9H), 7.49 – 7.40 (m, 10H), 7.40 – 7.28 (m, 20H), 7.11 – 7.04 (m, 5H), 7.00 (s, 1H), 1.55-1.50 (m, 4H), 1.26-1.18 (m, 27H), 0.90-0.86 (m, 12H).

[0122] Synthesis Example 5

[0123] The preparation method was the same as in Example 1, except that compound A5 (11.30 g) was used to replace compound A1, and the final product B5 was obtained: 0.55 g, MS (m / z) (M+): 1222.

[0124] 1 H NMR (400 MHz, CDCl3) δ 8.71 (s, 1H), 7.65 (s, 1H), 7.57 (dd, 4H), 7.46 (d, 1H), 7.40 (d, 1H), 7.33 (d, 3H), 7.25 – 7.17 (m, 4H), 6.91 (s, 1H), 6.72 (d, 2H), 6.64 (d, 2H), 6.57 (d, 1H), 6.11 (s, 1H), 1.46 – 1.39 (m, 27H), 1.34 (s, 9H), 0.88 – 0.80 (m, 18H).

[0125] Synthesis Example 6

[0126] The preparation method was the same as in Example 1, except that compound A6 (13.07 g) was used to replace compound A1, and the final product B6 was obtained: 0.60 g, MS (m / z) (M+): 1234.

[0127] 1H NMR (400 MHz, CDCl3) δ = 8.22 (dd, 1H), 7.64 – 7.56 (m, 8H), 7.52 –7.48 (m, 2H), 7.46 (s, 1H), 7.44 (s, 2H), 7.40 (d, 1H), 7.38 – 7.33 (m, 10H),7.27 (d, 1H), 7.26 – 7.23 (m, 3H), 7.11 (s, 1H), 7.04 (d, 1H), 7.02 (d, 1H),1.84 – 1.74 (m, 2H), 1.68 – 1.58 (m, 2H), 1.08 – 1.02 (m, 27H), 0.95-0.89 (m, 12H).

[0128] Synthesis Example 7

[0129] The preparation method is the same as in Synthesis Example 1, except that compound A7 (12.78 g) is replaced with compound A1, and the final product B7 is obtained: 0.65 g, MS (m / z) (M+): 1207.

[0130] 1 H NMR (400 MHz, CDCl3) δ 7.60 – 7.49 (m, 6H), 7.49 – 7.41 (m, 7H), 7.41 – 7.33 (m, 12H), 7.32 (s, 4H), 7.27 (d, 2H), 7.25 – 7.17 (m, 4H), 7.10(dd, 1H), 7.04(d, 1H), 0.94-0.84(m, 54H).

[0131] Synthesis Example 8

[0132] The preparation method was the same as in Example 1, except that compound A8 (14.40 g) was used to replace compound A1, and the final product B8 was obtained: 0.74 g, MS (m / z) (M+): 1456.

[0133] 1H NMR (400 MHz, CDCl3) δ 7.57 – 7.51 (m, 3H), 7.45 (td, 7H), 7.37 (q,10H), 7.35 – 7.29 (m, 5H), 7.27 (s, 3H), 7.20 (d, 1H), 7.10 (dd, 1H), 7.04(d, 1H), 7.00 (d, 1H), 6.96 (s, 1H), 6.67 (dd, 1H), 1.56-1.51 (m, 12H), 1.35(s, 9H), 1.27-1.21 (m, 18H), 0.95-0.82 (m, 36H).

[0134] Synthesis Example 9

[0135] The preparation method was the same as in Example 1, except that compound A9 (12.74 g) was used to replace compound A1, and the final product B9 was obtained: 0.75 g, MS (m / z) (M+): 1203.

[0136] 1 H NMR (400 MHz, CDCl3) δ 7.53 (s, 2H), 7.50 – 7.40 (m, 11H), 7.40 –7.29 (m, 14H), 7.20 (d, 1H), 7.14 (d, 1H), 7.12 – 7.06 (m, 6H), 7.04 (d, 1H), 6.97 (dd, 1H), 1.43-1.40 (m, 8H), 1.37-1.34 (m, 18H), 0.89-0.81 (m, 24H).

[0137] Synthesis Example 10

[0138] The preparation method was the same as in Example 1, except that compound A10 (14.40 g) was replaced with compound A1, and the final product B10 was obtained: 0.81 g, MS (m / z) (M+): 1477.

[0139] 1H NMR (400 MHz, CDCl3) δ 7.57 – 7.51 (m, 3H), 7.50 – 7.42 (m, 7H), 7.41 – 7.35 (m, 10H), 7.35 – 7.29 (m, 5H), 7.27 (s, 3H), 7.20 (d, 1H), 7.10(dd, 1H), 7.04 (d, 1H), 7.00 (d, 1H), 6.96 (s, 1H), 6.67 (dd, 1H), 1.44-1.40(m, 12H), 1.25 (s, 9H), 1.11-1.06 (m, 18H), 0.91-0.86 (m, 36H).

[0140] Synthesis Example 11

[0141] The preparation method was the same as in Synthesis Example 1, except that compound A11 (12.56 g) was replaced with compound A1, and the final product B11 was obtained: 0.58 g, MS (m / z) (M+): 1185.

[0142] 1 H NMR (400 MHz, CDCl3) δ 7.54 (t, 1H), 7.51 (d, 1H), 7.45 (ddd, 7H), 7.41 – 7.33 (m, 12H), 7.27 (d, 2H), 7.25 – 7.17 (m, 4H), 7.14 (d, 1H), 7.12 –7.06 (m, 2H), 7.04 (d, 1H), 6.97 (dd, 1H), 1.54-1.50 (s, 4H), 1.27-1.22 (m,18H), 1.18 (s, 9H), 1.15-1.10 (m, 18H), 0.98-0.92 (m, 12H).

[0143] Synthesis Example 12

[0144] The preparation method is the same as in Synthesis Example 1, except that compound A12 (12.56g) is replaced with compound A1, and the final product B12 is obtained: 0.56g, MS (m / z) (M+): 1185.

[0145] 1H NMR (400 MHz, CDCl3) δ 8.70 (s, 1H), 7.53 (d, 2H), 7.36 (d, 9H), 7.30 (d, 4H), 7.20 (t, 9H), 7.07 (d, 1H), 6.91 (d, 1H), 6.72 (d, 2H), 6.59(br, 2H), 6.03 (s, 1H), 1.73 (dd, 4H), 1.42 (dd, 18H), 1.37 (d, 6H), 1.12 (s,12H), 0.84-0.80 (m, 21H).

[0146] Synthesis Example 13

[0147] The preparation method was the same as in Example 1, except that compound A13 (15.19 g) was used to replace compound A1, and the final product B13 was obtained: 0.85 g, MS (m / z) (M+): 1448.

[0148] 1 H NMR (400 MHz, CDCl3) δ 7.71 (d, 1H), 7.54 (dd, 4H), 7.51 (d, 1H), 7.49 – 7.42 (m, 6H), 7.41 – 7.29 (m, 15H), 7.29 – 7.18 (m, 7H), 7.08 (s, 1H), 7.00 (s, 2H), 6.67 (dd, 1H), 1.44-1.40 (m, 8H), 1.27 (s, 9H), 1.02-0.88 (m, 60H).

[0149] Synthesis Example 14

[0150] The preparation method was the same as in Synthesis Example 1, except that compound A14 (14.08 g) was used to replace compound A1, and the final product B14 was obtained: 0.74 g, MS (m / z) (M+): 1337.

[0151] 1H NMR (400 MHz, CDCl3) δ 7.60 (d, 1H), 7.59 – 7.50 (m, 10H), 7.49 – 7.42 (m, 6H), 7.41 – 7.33 (m, 12H), 7.31 (d, 7H), 7.27 (s, 3H), 7.22 (dd,1H), 1.64-1.60 (m, 4H), 1.37 (s, 9H), 1.25-1.17 (m, 36H), 0.89-0.82 (m, 12H).

[0152] Synthesis Example 15

[0153] The preparation method was the same as in Example 1, except that compound A15 (15.39 g) was replaced with compound A1, and the final product B15 was obtained: 0.75 g, MS (m / z) (M+): 1467.

[0154] 1 H NMR (400 MHz, CDCl3) δ 8.16 (d, 1H), 7.62 – 7.51 (m, 8H), 7.50 –7.41 (m, 7H), 7.41 – 7.33 (m, 14H), 7.31 (d, 5H), 7.27 (d, 2H), 7.25 – 7.17(m, 2H), 7.00 (d, 2H), 6.67 (dd, 2H), 1.45-1.40 (t, 8H), 1.30 (s, 9H), 1.22(s, 9H), 1.15-1.10 (m, 18H), 0.92-0.84 (m, 24H).

[0155] Synthesis Example 16

[0156] The preparation method was the same as in Synthesis Example 1, except that compound A16 (13.71 g) was used to replace compound A1, and the final product B16 was obtained: 0.64 g, MS (m / z) (M+): 1301.

[0157] 1H NMR (400 MHz, CDCl3) δ 7.55 – 7.49 (m, 5H), 7.49 – 7.40 (m, 14H), 7.40 – 7.31 (m, 16H), 7.22 (dd, 1H), 7.11 – 7.04 (m, 9H), 7.00 (s, 1H), 1.44-1.40 (m, 4H), 1.16-1.08 (m, 27H), 1.00-0.94 (m, 12H).

[0158] Synthesis Example 17

[0159] The preparation method was the same as in Synthesis Example 1, except that compound A17 (16.51g) was used to replace compound A1, and the final product B17 was obtained: 0.66g, MS (m / z) (M+): 1579.

[0160] 1 H NMR (400 MHz, CDCl3) δ 8.16 (d, 1H), 7.61 – 7.52 (m, 9H), 7.49 – 7.43 (m, 6H), 7.41 – 7.33 (m, 12H), 7.33 – 7.24 (m, 11H), 6.96 (s, 2H), 1.42-1.39 (m, 8H), 1.23-1.19 (m, 18H), 1.15-1.02 (m, 36H), 0.98-0.90 (m, 24H).

[0161] Synthesis Example 18

[0162] The preparation method was the same as in Example 1, except that compound A18 (14.67 g) was replaced with compound A1, and the final product B18 was obtained: 0.92 g, MS (m / z) (M+): 1395.

[0163] 1H NMR (400 MHz, CDCl3) δ 8.16 (d, 1H), 7.59 – 7.52 (m, 5H), 7.45 (ddd, 8H), 7.41 – 7.33 (m, 12H), 7.32 (s, 2H), 7.27 (d, 4H), 7.25 – 7.16 (m,5H), 7.13 – 7.01 (m, 2H), 1.27-1.20 (m, 18H), 1.15 (s, 9H), 1.10 (s, 9H), 0.95-0.87 (m, 36H).

[0164] Synthesis Example 19

[0165] The preparation method was the same as in Example 1, except that compound A19 (13.11 g) was used to replace compound A1, and the final product B19 was obtained: 0.63 g, MS (m / z) (M+): 1239.

[0166] 1 H NMR (400 MHz, CDCl3) δ 8.50 (br, 1H), 7.54 (d, 2H), 7.34 (d, 9H), 7.28 (d, 4H), 7.18 (t, 9H), 6.95 (d, 1H), 6.76 (d, 2H), 6.56 (br, 2H), 6.04(s, 1H), 1.70 (dd, 9H), 1.56 (s, 4H), 1.44 (d, 12H), 1.11 (s, 18H), 0.86-0.80(m, 27H).

[0167] Synthesis Example 20

[0168] The preparation method was the same as in Synthesis Example 1, except that compound A20 (12.79 g) was replaced with compound A1, and the final product B20 was obtained: 0.74 g, MS (m / z) (M+): 1207.

[0169] 1H NMR (400 MHz, CDCl3) δ 8.72 (d, 1H), 7.74 (d, 1H), 7.70 (s, 1H), 7.68 (d, 2H), 7.57 (s, 2H), 7.55 (d, 2H), 7.40 – 7.34 (m, 11H), 7.28 (s, 1H),7.26 (s, 1H), 7.25 (d, 2H), 7.18 (t, 6H), 6.91 (s, 1H), 6.72 (d, 2H), 6.64(s, 2H), 6.57 (s, 1H), 6.04 (d, 1H), 1.42 (d, 27H), 1.10 (s, 9H), 0.84 (s,18H).

[0170] Synthesis Example 21

[0171] The preparation method was the same as in Example 1, except that compound A21 (12.78 g) was replaced with compound A1, and the final product B21 was obtained: 0.71 g, MS (m / z) (M+): 1207.

[0172] 1 H NMR (400 MHz, CDCl3) δ 8.71 (s, 1H), 7.73 (t, 2H), 7.59 (d, 4H), 7.56 (d, 2H), 7.46 (t, 2H), 7.40 (dd, 9H), 7.33 (br, 2H), 7.31 (s, 1H), 7.30– 7.27 (m, 2H), 7.23 (s, 2H), 7.21 (s, 3H), 7.19 (s, 1H), 6.92 (s, 1H), 6.75(d, 2H), 6.62 (br, 2H), 6.12 (s, 1H), 1.45 (s, 9H), 1.43 (d, 18H), 1.10 (s, 9H), 0.86 (s, 18H).

[0173] Synthesis Example 22

[0174] The preparation method was the same as in Synthesis Example 1, except that compound A22 (12.78 g) was replaced with compound A1, and the final product B22 was obtained: 0.69 g, MS (m / z) (M+): 1207.

[0175] 1H NMR (400 MHz, CDCl3) δ 8.74 (s, 1H), 7.69 (s, 1H), 7.63 (d, 1H), 7.59 (d, 3H), 7.50 (d, 1H), 7.44 – 7.40 (m, 8H), 7.34 – 7.29 (m, 6H), 7.24 –7.18 (m, 9H), 6.94 (s, 1H), 6.76 (d, 2H), 6.68 (br, 2H), 6.60 (br, 1H), 6.15(s, 1H), 1.48 (s, 9H), 1.46 (d, 18H), 1.36 (s, 9H), 0.89 (s, 18H).

[0176] Synthesis Example 23

[0177] The preparation method was the same as in Synthesis Example 1, except that compound A23 (12.78 g) was replaced with compound A1, and the final product B23 was obtained: 0.62 g, MS (m / z) (M+): 1207.

[0178] 1 H NMR (400 MHz, CDCl3) δ 8.78 (d, 1H), 7.63 (d, 1H), 7.57 (d, 2H), 7.54 – 7.47 (m, 3H), 7.43 (d, 1H), 7.42 – 7.36 (m, 10H), 7.32 (dt, 5H), 7.21(t, 7H), 6.96 (s, 1H), 6.89 (s, 1H), 6.63 (d, 2H), 6.58 (d, 1H), 6.32 (s,1H), 6.23 (s, 1H), 1.50 (s, 9H), 1.45 (s, 9H), 1.35 (d, 18H), 0.75 (s, 18H).

[0179] Synthesis Example 24

[0180] The preparation method was the same as in Example 1, except that compound A24 (13.33 g) was replaced with compound A1, and the final product B24 was obtained: 0.58 g, MS (m / z) (M+): 1261.

[0181] 1H NMR (400 MHz, CDCl3) δ 8.78 (d, 1H), 7.63 (d, 1H), 7.57 (d, 2H), 7.54 – 7.47 (m, 3H), 7.43 (d, 1H), 7.42 – 7.36 (m, 10H), 7.32 (dt, 5H), 7.21(t, 7H), 6.96 (s, 1H), 6.89 (s, 1H), 6.63 (d, 2H), 6.58 (d, 1H), 6.32 (s,1H), 6.23 (s, 1H), 1.50 (s, 9H), 1.45 (s, 9H), 1.35 (d, 18H), 0.75 (s, 18H).

[0182] Synthesis Example 25

[0183] The preparation method is the same as in Synthesis Example 1, except that compound A25 (13.85g) is replaced with compound A1, and the final product B25 is obtained: 0.60g, MS (m / z) (M+): 1315.

[0184] 1 H NMR (400 MHz, CDCl3) δ 8.70 (s, 1H), 7.74 (d, 2H), 7.64 (s, 1H), 7.61 (d, 1H), 7.56 (d, 1H), 7.48 (t, 3H), 7.44 (s, 1H), 7.42 (d, 3H), 7.39(d, 4H), 7.37 (d, 1H), 7.32 (s, 1H), 7.30 (s, 2H), 7.28 (s, 1H), 7.21 (t,7H), 6.91 (d, 2H), 6.64 (d, 2H), 6.55 (s, 1H), 6.37 (s, 1H), 6.15 (d, 1H),1.79 (s, 4H), 1.71 (d, 4H), 1.50 (d, 12H), 1.46 (d, 9H), 1.38 (s, 6H), 1.21 (s, 9H), 1.08 (d, 6H), 0.79 (s, 18H).

[0185] Synthesis Example 26

[0186] The preparation method was the same as in Example 1, except that compound A26 (13.55 g) was replaced with compound A1, and the final product B26 was obtained: 0.58 g, MS (m / z) (M+): 1283.

[0187] 1 H NMR (400 MHz, CDCl3) δ 8.78 (d, 1H), 7.79 (d, 1H), 7.71 (d, 3H), 7.65 (s, 3H), 7.59 (d, 5H), 7.53 (d, 4H), 7.45 (d, 3H), 7.41 (s, 3H), 7.39(d, 3H), 7.24 (s, 2H), 7.20 (s, 2H), 7.18 (s, 3H), 7.16 (s, 1H), 6.96 (s,1H), 6.91 (s, 1H), 6.65 (d, 2H), 6.38 (s, 1H), 6.25 (d, 1H), 1.45 (s, 9H), 1.44 (s, 9H), 1.41 (s, 9H), 1.17 (s, 9H), 0.77 (s, 18H).

[0188] Comparative Example The following are some compounds that were tested during the research process, with their specific structural formulas as follows:

[0189] Compound performance evaluation By calculating the vibrational relaxation energy (excited-state recombination energy λ, in kJ / mol) generated during the excitation and emission processes of the molecule, the effect of introducing triphenylsilane and benzofuran groups on the vibrational relaxation of the compound provided in this invention can be determined. A smaller excited-state recombination energy indicates less vibrational relaxation during excitation, resulting in a narrower emission spectrum. The following methods were used: Using ORCA 6.0.1 software, geometric optimization and vibrational analysis (Opt+freq) were performed on the ground state structure of the molecule based on density functional theory (DFT) calculations (basis set level set: b3lyp-d3 / 6-31G(d), charge number 0). Geometric optimization and vibrational analysis (Opt+freq) were also performed on the first singlet excited state (S1) structure of the molecule based on time-dependent density functional theory (TD-DFT) calculations (basis set level set: b3lyp-d3 / 6-31G(d), charge number 0). All calculated structures did not exhibit imaginary frequencies. Subsequently, energy decomposition was performed using Dushin software based on the molecular vibrational modes in the ground state and the first singlet excited state. Based on the Huang Kun factor and wavenumber obtained from the energy decomposition, the contributions of each vibrational mode to the recombination energy were summed, and the excited-state recombination energy λ (kJ / mol) of the fluorescence emission process of the compound provided in this invention was calculated.

[0190] On the other hand, since Dexter energy transfer leads to a decrease in device efficiency, increasing the number of alkyl substituents can increase the intermolecular distance, thereby reducing the probability of Dexter energy transfer. This can be achieved by measuring the intermolecular distance using XRD single-crystal diffraction.

[0191] Table 1 lists the excited-state recombination energies and intermolecular distances for different compounds.

[0192] Table 1

[0193] The data in the table above show that simultaneously introducing benzofuran and triphenylsilyl substituents into the molecule significantly reduces energy loss due to vibrational relaxation during excitation. Furthermore, while the multiple tert-butyl groups increase the intermolecular distance, the three phenyl groups on the triphenylsilane also contribute to increasing the intermolecular distance, which is beneficial for improving the material's dispersion during device fabrication and reducing the probability of Dexter energy transfer.

[0194] Compared to comparative compound D1, the introduction of benzofuran and triphenylsilyl groups significantly reduces the energy loss caused by vibrational relaxation during excitation. Comparative compounds D2 and D3 show that the individual use of benzofuran and triphenylsilyl groups has no significant effect on the excited-state recombination energy and intermolecular distance. However, comparative compound D4 demonstrates that reducing the number of tert-butyl groups leads to a significant decrease in intermolecular distance, thereby increasing the probability of Dexter energy transfer.

[0195] Device Examples The anode in the following embodiments uses anode materials commonly used in the art, such as ITO, Ag, or their multilayer structures. The hole injection unit uses hole injection materials commonly used in the art, with the addition of F4TCNQ, HATCN, NDP-9, etc., for doping. The hole transport unit uses hole transport materials commonly used in the art. The light-emitting unit uses light-emitting materials commonly used in the art; for example, it can be composed of a host material and an emitting guest material, where the emitting guest material can be an organic material such as a pyrene compound, or a metal complex (such as metal Ir, Pt, etc.). The electron transport unit uses electron transport materials commonly used in the art. The electron injection layer uses electron injection materials commonly used in the art, such as LiQ, LiF, Yb, etc. The cathode uses materials commonly used in the art, such as metal Al, Ag, or metal mixtures (Ag-doped Mg, Ag-doped Ca, etc.).

[0196] The electrode fabrication methods and the deposition methods of each functional layer in the following embodiments are all conventional methods in the art, such as vacuum thermal evaporation or inkjet printing, and will not be described in detail here. Only some process details and testing methods in the fabrication process are supplemented as follows: Device Example 1 This embodiment provides a blue organic light-emitting device, which is fabricated as follows: An ITO substrate is patterned to have a light-emitting area of ​​3mm × 3mm, followed by ultrasonication with water / isopropanol, UV / ozone irradiation, and then drying at 100°C. The ITO substrate is then mounted on a substrate support in a vacuum deposition apparatus, and the pressure is adjusted to achieve a vacuum rate of 1 × 10⁻⁶. - 7torr. Then, the following operations are performed: First, a hole injection layer is formed on the ITO layer (anode) formed on the substrate by vacuum deposition of compounds HT01 and PD01 (mass ratio of HT01 to PD01 is 97:3) with a thickness of 10 nm; second, a hole transport layer is formed on the hole injection layer by vacuum deposition of compound HT01 with a thickness of 100 nm; third, a light-emitting auxiliary layer is formed on the hole transport layer by vacuum deposition of compound BP01 with a thickness of 5 nm; fourth, a light-emitting layer is formed on the light-emitting auxiliary layer by vacuum deposition of a mixture of compound B1 and compound BH01 provided by the present invention with a thickness of 20 nm, wherein BH01 is used as the host material and compound B1 is used as the guest material, and the mass ratio of compound BH01 to compound B1 is 98:2; then, a hole blocking layer is formed on the light-emitting layer by vacuum deposition of compound HB01 with a thickness of 5 nm; then… Subsequently, on the aforementioned hole-blocking layer, a 30 nm thick layer of compound ET01 and compound LiQ (with a mass ratio of 1:1) was vacuum-deposited to form an electron transport layer. Then, on the electron transport layer, a 1 nm thick layer of Yb was vacuum-deposited to form an electron injection layer. Next, on the electron injection layer, a 15 nm thick layer of Mg and Ag (with a mass ratio of 1:9) was deposited to form a cathode. Then, on the cathode, a 50 nm thick layer of compound CP01 was deposited to form a capping layer. Finally, the vapor-deposited substrate was encapsulated. A UV adhesive coating process was used to coat the cleaned cover plate. The coated cover plate was then moved to the lamination section, and the vapor-deposited substrate was placed on top of the cover plate. Finally, the substrate and cover plate were laminated using a bonding device, while simultaneously curing the UV adhesive under light. This process fabricated a top-emitting organic light-emitting device. The device structure is described in [reference needed]. Figure 1 .

[0197] Except for the blue light doping material, the molecular structures of the other layers are as follows:

[0198]

[0199] .

[0200] Device Examples 2-26 This embodiment provides a blue organic electroluminescent device, which is prepared by replacing compound B1 in device embodiment 1 with compounds B2 to B26 provided in compounds 2 to 26 to form an emitting layer. Other preparation steps are the same as in device embodiment 1, and blue organic electroluminescent devices are prepared accordingly.

[0201] Device Comparison Examples 1-4 The method is the same as in Device Example 1, except that compound B1 in Device Example 1 is replaced with compounds D1 to D5 to form the light-emitting layer. Other preparation steps are the same as in Device Example 1, and blue organic electroluminescent devices are prepared respectively.

[0202] Performance evaluation of organic electroluminescent devices The OLED devices described above were tested using standard methods. For this purpose, J = 10 mA / cm² was used. 2 The driving voltage, luminance, electroluminescent current efficiency (in cd / A), and external quantum efficiency (EQE, in percentage) of the organic electroluminescent device were determined at a given current density. The emission spectrum was calculated as a function of luminescence density from the current / voltage / luminescence density characteristic line (IVL characteristic line), which exhibits Lambertian emission characteristics. The lifetime LT was defined as the time after which, when operating at a constant current J, the luminance decreases from the initial luminance L0 to a specific proportion L1; J = 20 mA / cm². 2 The statement L1 = 97% refers to a value of 20 mA / cm². 2 When operating below this threshold, the luminous intensity decreases to 97% of its initial value L0 after time LT. (At J = 20 mA / cm²) 2 The lifetime (LT97) of the organic electroluminescent device was determined at a given current density.

[0203] Table 2 summarizes the data for various OLED devices. The parameters of the device examples and comparative examples are compared to demonstrate the performance data of the various OLED devices.

[0204] The testing instruments and methods used to perform performance testing on the OLED devices of the above embodiments and comparative examples are as follows: Quantum efficiency (CE) (cd / A), chromaticity coordinates (CIEy), and emission half-width were measured using a PhotoResearch PR-655 spectral scanner. Current density and turn-on voltage: tested using a Keithley 2400 digital source meter; The blue index is obtained by dividing the quantum efficiency CE (cd / A) by the color coordinate (CIEy); Life test: The LT-96ch life test device was used.

[0205] Table 2 Performance test results of blue light devices

[0206] The verification results from the device examples show that, by simultaneously introducing benzofuran and triphenylsilyl substituents into the molecule, compared to the same multi-tert-butyl structure, the device's operating efficiency is significantly improved due to reduced energy loss during the excitation process. Furthermore, the suppression of vibrational relaxation also results in a reduced emission half-width and improved color purity, exhibiting narrow spectral characteristics that meet the spectral requirements of the BT.2020 wide color gamut standard.

[0207] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A polycyclic compound containing triphenylsilane and polyalkyl substituents, characterized in that, The general structural formula of the polycyclic compound is shown in Formula I: I； Wherein, R1 and R2 may be the same or different, and each independently represents any one of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl with C1 to C30 carbon atoms, substituted or unsubstituted cycloalkyl with C3 to C30 carbon atoms, substituted or unsubstituted aryl with C6 to C60 carbon atoms, substituted or unsubstituted heteroaryl with C5 to C60 carbon atoms, substituted or unsubstituted fused-ring aryl with C6 to C60 carbon atoms, and substituted or unsubstituted heterofused-ring aryl with C5 to C60 carbon atoms. Two or more R1 and R2 may be connected to each other to form an aliphatic ring, an aromatic ring, or a fused ring. Each time R appears, it independently represents any one of the following: a substituted or unsubstituted aryl group with C6 to C60 carbon atoms, a substituted or unsubstituted heteroaryl group with C5 to C60 carbon atoms, a substituted or unsubstituted fused-ring aryl group with C6 to C60 carbon atoms, or a substituted or unsubstituted heterofused-ring aryl group with C5 to C60 carbon atoms. m and n each independently represent 0, 1, 2, 3 or 4; When R1, R2, and R contain substituents, the substituents are selected from alkyl groups having C1 to C10 carbon atoms or aryl groups having C6 to C20 carbon atoms; two or more of the substituents may be linked together to form an aliphatic ring; The polycyclic compound contains at least one 5 tert-butyl groups; or A ring structure consisting of three tert-butyl groups and one ring formed by connecting any two adjacent tert-butyl groups. Any hydrogen in Formula I can be substituted with deuterium or alkyl groups.

2. The polycyclic compound according to claim 1, characterized in that, R1 and R2 each independently represent any one of the following: a substituted or unsubstituted alkyl group with C1 to C10 carbon atoms, or a substituted or unsubstituted aryl group with C6 to C30 carbon atoms. Two or more R1 and R2 can be connected to each other to form an aliphatic ring.

3. The polycyclic compound according to claim 1, characterized in that, Each time R appears, it independently represents a substituted or unsubstituted aryl group with a carbon number of C6 to C20.

4. The polycyclic compound according to claim 1, characterized in that, Each time R appears, it independently represents any one of substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, or substituted or unsubstituted terphenyl.

5. The polycyclic compound according to claim 4, characterized in that, The general structural formula of the polycyclic compound is shown in one of the following: I-1、 I-2、 I-3、 I-4; R3 represents one of the following structures: 、 、 、 、 、 、 、 ； R4 represents one of the following structures: 、 、 、 、 ； Any hydrogen atom in the above groups can be replaced by deuterium or tert-butyl, and at least one hydrogen atom in the above groups can be replaced by tert-butyl. When more than one hydrogen atom is replaced, two adjacent tert-butyl groups can be linked together to form a ring structure.

6. The polycyclic compound according to claim 5, characterized in that, R3 represents one of the following structures: 、 、 、 、 ； and / or R4 represents one of the following structures: 、 、 、 、 、 。 7. The polycyclic compound according to claim 1, characterized in that, R1 and R2 are represented independently. , , One of them; When R1 represents tert-butyl, two adjacent R1 positions can be connected to each other to form a ring structure; When R2 represents tert-butyl, two adjacent R2 positions can be connected to form a ring structure.

8. The polycyclic compound according to claim 1, characterized in that, The polycyclic compounds are selected from the structures shown below: 。 9. An organic electroluminescent device, characterized in that, It includes an anode, a hole transport region, a light-emitting layer, an electron transport region, and a cathode sequentially disposed on a substrate; wherein the light-emitting layer includes a host material and a dopant material, and the dopant material includes one or more polycyclic compounds as described in any one of claims 1-8.

10. The organic electroluminescent device according to claim 9, characterized in that, The main material is selected from the following general structure: II; in, L is selected from single bonds or phenylene; Ar1 is selected from phenyl or naphthyl; Ar2 represents one of the following groups: 、 、 、 ； Any hydrogen in Formula II may be substituted with deuterium, alkyl or aryl.

11. The organic electroluminescent device according to claim 9, characterized in that, The main material is selected from the structure shown below: 。

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