Intramolecular ring-closed organic electroluminescent material constructed based on indolocarbazole and derivatives thereof as well as preparation method and application of intramolecular ring-closed organic electroluminescent material

Abstract

The invention discloses an intramolecular ring-closed organic electroluminescent material constructed based on indolocarbazole and derivatives thereof as well as a preparation method and application of the intramolecular ring-closed organic electroluminescent material, and belongs to the technical field of organic photoelectric materials. Narrow spectrum emission is realized through different back ring modification. According to the intramolecular ring-closed organic electroluminescent material constructed on the basis of indolocarbazole and the derivatives thereof and the preparation method and application of the intramolecular ring-closed organic electroluminescent material, the prepared material can achieve narrow-spectrum emission and high exciton utilization rate, is excellent in electroluminescent performance, can be widely applied to the fields of organic electroluminescence and the like, and has a wide application prospect. Meanwhile, the preparation method of the organic electroluminescent material is simple, and raw materials are easy to obtain.

Description

Technical Field

[0001] This invention relates to the field of organic optoelectronic materials technology, and in particular to an organic electroluminescent material based on intramolecular cyclic closure constructed from indolecarbazole and its derivatives, its preparation method, and its application. Background Technology

[0002] Organic light-emitting diodes (OLEDs), also known as organic light-emitting diodes, are a class of devices that convert electrical energy into light energy based on organic light-emitting materials. Compared with traditional liquid crystal display technology, OLEDs have many inherent advantages, such as being ultra-thin and lightweight, having a fast response speed, high resolution, low power consumption, vibration resistance, low temperature resistance, and flexibility.

[0003] With the increasing demand for full-color high-definition displays, the development of organic electroluminescent materials with high color purity, high efficiency, and long device lifetime has attracted widespread attention. Thermally activated delayed fluorescence (TADF, Nature 492, 234–238 (2012)) materials utilize their small singlet-triplet energy level difference (ΔE) to achieve high performance. ST Organic light-emitting diodes (TADFs) can utilize triplet excitons through reverse intersystem crossing (RISC) processes, achieving 100% internal quantum efficiency and becoming the latest generation of organic electroluminescent materials. However, the molecular structure of TADF materials typically consists of electron donor and electron acceptor groups connected in a conjugated or non-conjugated manner, resulting in luminescence primarily originating from intramolecular charge transfer (ICT) state transitions. This structure leads to excessively broad emission spectra (half-width at half maximum exceeding 100 nm) in most TADF materials, making it difficult to meet the high color purity requirements of the display industry. Therefore, developing a simple and efficient method to prepare organic light-emitting materials with high luminescence efficiency and good stability is a technical problem urgently needing to be solved by those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to provide an intramolecularly cyclic organic electroluminescent material based on indolecarbazole and its derivatives, its preparation method, and its application. This material can achieve narrow-spectrum emission and high exciton utilization, exhibiting excellent electroluminescence performance. It can be widely used in fields such as organic electroluminescence. Furthermore, the preparation method of this organic electroluminescent material is simple, and the raw materials are readily available.

[0005] To achieve the above objectives, this invention provides an organic electroluminescent material based on indole-carbazole and its derivatives, comprising an intramolecular cyclic closure. The structural formula of this organic electroluminescent material is as follows:

[0006]

[0007] Wherein, A includes substituted or unsubstituted benzene rings, and substituted or unsubstituted C rings. 10 -C 50 fused aromatic rings and substituted or unsubstituted C4-C 50 One of the fused heterocycles, R1 includes H, C1-C 12 Alkyl, C1-C 12 Alkoxy, C6-C 18 Aryl and C5-C 18 One of the heteroaryl groups, where R2 includes H, C1-C 12 Alkyl, C1-C 12 Alkoxy, C6-C 18 Aryl and C5-C 18 One of the heteroaryl groups, where R3 includes H, C1-C 12 Alkyl, C1-C 12 Alkoxy, C6-C 18 Aryl and C5-C 18 One of the heteroaryl groups, where R4 includes H, C1-C 12 Alkyl, C1-C 12 Alkoxy, C6-C 18 Aryl and C5-C 18 One of the heteroaryl groups.

[0008] Preferred, substituted or unsubstituted C 10 -C 50 The fused aromatic ring includes one of a substituted or unsubstituted naphthalene ring, a substituted or unsubstituted anthracene ring, and a substituted or unsubstituted phenanthrene ring, wherein the substituted or unsubstituted C4-C ring is... 50 The fused heterocycles include one of the following: a substituted or unsubstituted furan ring, a substituted or unsubstituted thiophene ring, and a substituted or unsubstituted six-membered heteroaromatic ring containing 1-2 N atoms.

[0009] Preferably, A is connected to indolecarbazole or an indolecarbazole derivative in an ortho position, and after connection, intramolecular ring closure is performed to form a six-membered ring.

[0010] Preferably, the structural formula of A includes one of 1-44:

[0011]

[0012] R' includes H, substituted or unsubstituted benzene rings, C1-C 12 Alkyl, C1-C 12 alkoxy, substituted or unsubstituted C6-C 18 Aryl and C5-C 18 One of the heteroaryl groups, where "R" includes H, a substituted or unsubstituted benzene ring, and C1-C2. 12 Alkyl, C1-C 12alkoxy, substituted or unsubstituted C6-C 18 Aryl and C5-C 18 One of the heteroaryl groups, where R”' includes H, a substituted or unsubstituted benzene ring, and C1-C2. 12 Alkyl, C1-C 12 alkoxy, substituted or unsubstituted C6-C 18 Aryl and C5-C 18 One of the heteroaryl groups, where R"" includes H, a substituted or unsubstituted benzene ring, and C1-C2. 12 Alkyl, C1-C 12 alkoxy, substituted or unsubstituted C6-C 18 Aryl and C5-C 18 One of the heteroaryl groups, This indicates that it is partially linked to indobenzocarbazole or an indobenzocarbazole derivative.

[0013] Furthermore, indolocarbazole and its derivatives are electron-donating groups, and A together with the benzene rings of indolocarbazole on both sides constitutes a conjugated planar center.

[0014] This invention also provides a method for preparing an intramolecularly cyclic-closed organic electroluminescent material based on indolecarbazole and its derivatives, comprising the following steps:

[0015] S1. Using dibromo-substituted aromatic ring compounds, indole-carbazole or indole-carbazole derivatives as raw materials, a mixed solvent is added under alkaline conditions and a catalyst, and the reaction is heated to obtain an intermediate product containing indole-carbazole or indole-carbazole derivatives.

[0016] The intermediates obtained in S2 and S1 are reacted with solvent and catalyst to obtain an organic electroluminescent material containing intramolecular cyclization of indole-carbazole or indole-carbazole derivatives.

[0017] Preferably, in S1, the dibromo-substituted aromatic ring compounds include 1,2-dibromobenzene, 2,3-dibromonaphthalene, 9,10-dibromophenanthrene, 3,4-dibromobenzonitrile, 1,2-dibromo-4-tert-butylbenzene, 3,4-dibromopyridine, 2,3-dibromopyrazine, 2,3-dibromoquinoline, 1,2-dibromonaphthalene, 3,4-dibromofuran, 3,4-dibromothiophene, 2,3-dibromofuran, 2,3-dibromothiophene, 6,7-dibromoquinoxaline, 2,3-dibromoquinoxaline, or 4,5-dibromophthalene. The boronic acid esters of dicarboxynitrile, indolocarbazole, or indolocarbazole derivatives include 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)indolo[3,2,1-jk]carbazole or 2,11-di-tert-butyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)indolo[3,2,1-jk]carbazole, the basic substance includes potassium carbonate, sodium carbonate, or sodium hydroxide, the catalyst is tetra(triphenylphosphine)palladium, and the mixed solvent is toluene, ethanol, and water.

[0018] Furthermore, in S1, the molar ratio of the dibromo-substituted aromatic ring compound to the borate ester of indolocarbazole or indolocarbazole derivative is 1:1.8-2.5, the molar ratio of the basic substance to the catalyst is 20:0.05-0.1, the volume ratio of toluene, ethanol and water is 4-8:1-3:1, the reaction temperature is 80-120℃, and the reaction time is 4-8h.

[0019] Preferably, in S2, the solvent is dichloromethane, the catalyst is anhydrous ferric chloride and nitromethane, the molar ratio of intermediate product to anhydrous ferric chloride is 1:8-12, the volume ratio of nitromethane to dichloromethane is 1:0.5-2, the reaction temperature is 0-3℃, and the reaction time is 0.5-2h.

[0020] The present invention also provides an application of an intramolecularly cyclic organic electroluminescent material based on indole-carbazole and its derivatives, wherein the intramolecularly cyclic organic electroluminescent material based on indole-carbazole and its derivatives is used as a guest light-emitting layer in the fabrication of organic electroluminescent devices in a doped or undoped manner.

[0021] Therefore, the present invention employs the above-mentioned organic electroluminescent material based on indole-carbazole and its derivatives with intramolecular cyclic closure, its preparation method, and its application, which has the following beneficial effects:

[0022] (1) The present invention prepared an organic electroluminescent material based on indolecarbazole and its derivatives with intramolecular cyclic closure. This type of organic electroluminescent material has high solid-state luminescence efficiency and high exciton utilization.

[0023] (2) The method for preparing the organic electroluminescent material based on indole-carbazole and its derivatives of the present invention is simple, the raw materials are readily available, and the resulting organic electroluminescent material has a stable structure and is easy to store.

[0024] (3) The organic electroluminescent material based on indolecarbazole and its derivatives of the present invention has excellent electroluminescence performance and can be widely used in organic electroluminescence and other fields.

[0025] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0026] Figure 1 This is the electroluminescence spectrum of a DtBuICz-Ph-c device prepared using DtBuICz-Ph-c obtained in Example 1 of this invention as the luminescent material;

[0027] Figure 2 This is a luminance-voltage-current density curve of a DtBuICz-Ph-c device prepared using DtBuICz-Ph-c obtained in Example 1 of this invention as the luminescent material.

[0028] Figure 3 This is a graph showing the external quantum efficiency of a DtBuICz-Ph-c device prepared using DtBuICz-Ph-c obtained in Example 1 of this invention as a luminescent material, as a function of brightness.

[0029] Figure 4 This is the electroluminescence spectrum of a DtBuICz-PCN-c device prepared using DtBuICz-PCN-c obtained in Example 2 of this invention as the luminescent material;

[0030] Figure 5 This is a brightness-voltage-current density curve of a DtBuICz-PCN-c device prepared using DtBuICz-PCN-c obtained in Example 2 of this invention as the luminescent material.

[0031] Figure 6 This is a graph showing the external quantum efficiency of a DtBuICz-PCN-c device prepared using DtBuICz-PCN-c obtained in Example 2 of this invention as a luminescent material, as a function of brightness. Detailed Implementation

[0032] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0033] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0034] Example 1

[0035] This invention provides a method for preparing an intramolecularly cyclic-closed organic electroluminescent material based on indolecarbazole and its derivatives, comprising the following steps:

[0036] S1. 1.39 mmol of 1,2-dibromobenzene, 2.92 mmol of 2,11-di-tert-butyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborin-2-yl)indol[3,2,1-jk]carbazole, 28 mmol of potassium carbonate, and 0.111 mmol of tetra(triphenylphosphine)palladium were added to a reaction flask. The mixture was purged three times, and 30 mL of a mixed solvent of toluene, water, and ethanol (volume ratio of toluene, ethanol, and water: 6:2:1) was added. The mixture was heated to 100 °C and reacted for 6 h. After extraction with dichloromethane and water, the product was concentrated and then subjected to column chromatography to obtain the intermediate o-DtBuICz-Ph.

[0037] S2. Take 1 mmol of the intermediate product obtained in S1 and add it to the reaction flask. Vacuum the flask three times, add 10 mL of dichloromethane under ice bath conditions, and then add anhydrous ferric chloride in nitromethane solution. The amount of anhydrous ferric chloride is 10 mmol and the volume of nitromethane is 10 mL. React at 0 °C for 1 h. After the reaction is completed, quench with 30 mL of methanol, then extract with dichloromethane and water, concentrate and then obtain the final product DtBuICz-Ph-c by column chromatography with a yield of 50%.

[0038] The preparation route is as follows:

[0039]

[0040]

[0041] The final product DtBuICz-Ph-c obtained in Example 1 was subjected to proton nuclear magnetic resonance spectroscopy (NMR 1H). 1 Characterized by 1H NMR and high-resolution mass spectrometry (HRMS): 1H NMR (400MHz, CDCl3) δ10.06(s,1H),9.43(s,1H),8.86(d,J=8.1Hz,1H),8.74(d,J =5.9Hz,2H),8.63(d,J=7.7Hz,1H),8.37(s,1H),8.26-8.22(m,3H),8.18(m,J=4. 6Hz,2H),7.93(d,J=8.4Hz,1H),7.80(d,J=8.5Hz,1H),7.69-7.62(m,3H),7.49(d d,J=8.5,1.9Hz,1H),1.67(s,9H),1.53(s,9H),1.47(s,9H),1.36(s,9H); HRMS(C 58 H 54 N2+H + ):m / z 778.4305[M+H + ,calcd 778.4305].

[0042] Example 2

[0043] This embodiment operates the same as Example 1, except that in S1, the added dibromo-substituted aromatic ring compound is 3,4-dibromobenzonitrile, and the amount of 3,4-dibromobenzonitrile is 1.58 mmol. The amounts of 2,11-di-tert-butyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)indol[3,2,1-jk]carbazole, potassium carbonate, and tetra(triphenylphosphine)palladium added are 3.32 mmol, 32 mmol, and 0.126 mmol, respectively, and the intermediate product obtained is o-DtBuICz-PCN. In S2, the final product obtained is DtBuICz-PCN-c, with a yield of 60%.

[0044] The preparation route is as follows:

[0045]

[0046] The final product DtBuICz-PCN-c prepared in Example 2 was subjected to proton nuclear magnetic resonance spectroscopy (NMR spectroscopy). 1 Characterized by 1H NMR and high-resolution mass spectrometry (HRMS): 1H NMR (500MHz, CDCl3) δ9.86-9.72(m,1H),9.18-9.03(m,1H),8.67(s,1H),8.53(d,J=4.7Hz,1H),8.39-8.30(m,2H),8.22-8.14(m,3H),8.06(s ,1H),7.91-7.58(m,6H),7.42(d,J=8.5Hz,1H),1.70(s,9H),1.55(m,J=2.3Hz,9H),1.48(dd,J=7.3,1.9Hz,9H),1.31(m,J=3.8Hz,9H); 59 H 53 N3+H + ):m / z 803.4217[M+H + ,calcd830.4217].

[0047] Example 3

[0048] This embodiment operates the same as Example 1, except that in S1, the added dibromo-substituted aromatic ring compound is 1,2-dibromo-4-tert-butylbenzene, and the amount of 1,2-dibromo-4-tert-butylbenzene is 1.56 mmol. The amounts of 2,11-di-tert-butyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)indol[3,2,1-jk]carbazole, potassium carbonate, and tetra(triphenylphosphine)palladium added are 3.28 mmol, 31 mmol, and 0.125 mmol, respectively, and the resulting intermediate product is o-DtBuICz-tBuPh. In S2, the final product obtained is DtBuICz-tBuPh-c, with a yield of 60%.

[0049] The preparation route is as follows:

[0050]

[0051] The final product DtBuICz-tBuPh-c prepared in Example 3 was subjected to proton nuclear magnetic resonance spectroscopy (NMR spectroscopy). 1 Characterized by 1H NMR and high-resolution mass spectrometry (HRMS): 1H NMR (500MHz, CDCl3) δ10.10(s,1H),9.44(s,1H),8.87(s,1H),8.76(m,J=3.4Hz,2H),8.60(d,J =9.1Hz,1H),8.44(s,1H),8.28-8.20(m,5H),7.96(d,J=8.2Hz,1H),7.82(dd,J=8.5,2.3Hz,1H) ,7.76(d,J=8.5Hz,1H),7.67(d,J=8.2Hz,1H),7.50(d,J=8.1Hz,1H),1.68(d,J=2.3Hz,9H),1. 63(d,J=2.3Hz,9H),1.53(d,J=2.3Hz,9H),1.48(d,J=2.3Hz,9H),1.37(d,J=2.3Hz,9H); HRMS(C 62 H 62 N2+H + ):m / z834.4905[M+H + ,calcd834.4905].

[0052] Example 4

[0053] This embodiment operates the same as Example 1, except that in S1, the added dibromo-substituted aromatic ring compound is 2,3-dibromonaphthalene, and the amount of 2,3-dibromonaphthalene is 1.49 mmol. The amounts of 2,11-di-tert-butyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)indol[3,2,1-jk]carbazole, potassium carbonate, and tetra(triphenylphosphine)palladium added are 3.13 mmol, 30 mmol, and 0.12 mmol, respectively. The volume of the mixed solvent added is 40 mL, and the intermediate product obtained is o-DtBuICz-23Na. In S2, the final product obtained is DtBuICz-23Na-c, with a yield of 50%.

[0054] The preparation route is as follows:

[0055]

[0056] The final product DtBuICz-23Na-c prepared in Example 4 was subjected to proton nuclear magnetic resonance spectroscopy (NMR 1H NMR spectroscopy). 1 Characterized by 1H NMR and high-resolution mass spectrometry (HRMS): 1H NMR (400MHz, CDCl3) δ9.94(d,J=10.1Hz,1H),9.45(d,J=12.5Hz,1H),9.21(d,J=1 0.2Hz,1H),8.96(d,J=13.1Hz,1H),8.69(s,1H),8.40(s,1H),8.25-8.04(m,8H), 7.89(d,J=9.6Hz,1H),7.75(d,J=8.0Hz,1H),7.65(d,J=8.7Hz,1H),7.54(s,2H), 7.46(d,J=8.3Hz,1H),1.69(s,9H),1.54(s,9H),1.47(s,9H),1.35(s,9H); HRMS(C 62 H 56 N2+H + ):m / z 828.4456[M+H + ,calcd 828.4456].

[0057] Example 5

[0058] This embodiment operates the same as Example 1, except that in S1, the added dibromo-substituted aromatic ring compound is 9,10-dibromophenanthrene, and the amount of 9,10-dibromophenanthrene is 1.53 mmol. The amounts of 2,11-di-tert-butyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)indol[3,2,1-jk]carbazole, potassium carbonate, and tetra(triphenylphosphine)palladium added are 3.22 mmol, 31 mmol, and 0.122 mmol, respectively, and the intermediate product obtained is o-DtBuICz-Phe. In S2, the final product obtained is DtBuICz-Phe-c, with a yield of 40%.

[0059] The preparation route is as follows:

[0060]

[0061]

[0062] The final product DtBuICz-Phe-c obtained in Example 5 was subjected to proton nuclear magnetic resonance spectroscopy (NMR spectroscopy). 1 Characterized by 1H NMR and high-resolution mass spectrometry (HRMS): 1H NMR (500MHz, CDCl3) δ9.19 (s, 2H), 8.57-8.55 (m, 2H), 8.47 (s, 2H), 8.27 (d, J = 2.2Hz, 2H), 8.23-8.21 (m, 2H), 8.18-8.17 (m, 2H), 7.9 8(d,J=2.2Hz,2H),7.56-7.53(m,4H),7.41(d,J=2.1Hz,1H),7.39(d,J=2.1Hz,1H),7.33(s,1H),1.36(s,18H),1.35(s,18H); HRMS(C 66 H 58 N2+H + ):m / z 878.4626[M+H + ,calcd 878.4626].

[0063] Example 6

[0064] This embodiment operates the same as Example 1, except that in S1, the added dibromo-substituted aromatic ring compound is 3,4-dibromopyridine, and the amount of 3,4-dibromopyridine is 1.61 mmol. The amounts of 2,11-di-tert-butyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)indol[3,2,1-jk]carbazole, potassium carbonate, and tetra(triphenylphosphine)palladium added are 3.38 mmol, 32 mmol, and 0.13 mmol, respectively, and the resulting intermediate product is o-DtBuICz-Pyd. In S2, the final product obtained is DtBuICz-Pyd-c, with a yield of 40%.

[0065] The preparation route is as follows:

[0066]

[0067] The final product DtBuICz-Pyd-c prepared in Example 6 was subjected to 1H NMR spectroscopy (NMR spectroscopy). 1 Characterized by 1H NMR and high-resolution mass spectrometry (HRMS): 1 H NMR(500MHz, CDCl3)δ9.22(s,1H),9.19(s,1H),8.68(dd,J=4.5,1.0Hz,1H),8.27-8.25(m,2H),8.17(d ,J=2.5Hz,2H),7.98(d,J=2.3Hz,2H),7.40(dd,J=7.8,2.1Hz,2H),1.36(s,18H),1.35(s,18H); HRMS(C 57 H 53 N3+H +):m / z 779.4226[M+H + ,calcd 779.4226].

[0068] Example 7

[0069] This embodiment operates the same as Example 1, except that in S1, the added dibromo-substituted aromatic ring compound is 2,3-dibromopyrazine, and the amount of 2,3-dibromopyrazine is 1.58 mmol. The amounts of 2,11-di-tert-butyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)indol[3,2,1-jk]carbazole, potassium carbonate, and tetra(triphenylphosphine)palladium added are 3.32 mmol, 32 mmol, and 0.13 mmol, respectively, and the resulting intermediate product is o-DtBuICz-Pyz. In S2, the final product obtained is DtBuICz-Pyz-c, with a yield of 40%.

[0070] The preparation route is as follows:

[0071]

[0072] The final product DtBuICz-Pyz-c prepared in Example 7 was subjected to proton nuclear magnetic resonance spectroscopy (NMR 1H). 1 Characterized by 1H NMR and high-resolution mass spectrometry (HRMS): 1 HNMR (500MHz, CDCl3) δ9.28(s,2H),8.84(s,2H),8.54(s,2H),8.28(d,J=2.2Hz,2H),8.17(d,J=1.9Hz,2H),7.98(d,J= 2.2Hz,2H),7.41(d,J=2.1Hz,1H),7.39(d,J=2.1Hz,1H),7.33(s,1H),7.32(s,1H),1.36(s,18H),1.35(s,18H); HRMS(C 56 H 52 N4+H + ):m / z 780.4216[M+H + ,calcd 780.4216].

[0073] Example 8

[0074] This embodiment operates the same as Example 1, except that in S1, the added dibromo-substituted aromatic ring compound is 2,3-dibromoquinoline, and the amount of 2,3-dibromoquinoline is 1.49 mmol. The amounts of 2,11-di-tert-butyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)indol[3,2,1-jk]carbazole, potassium carbonate, and tetra(triphenylphosphine)palladium added are 3.13 mmol, 30 mmol, and 0.12 mmol, respectively, and the resulting intermediate product is o-DtBuICz-ql. In S2, the final product obtained is DtBuICz-ql-c, with a yield of 55%.

[0075] The preparation route is as follows:

[0076]

[0077] The final product DtBuICz-ql-c prepared in Example 8 was subjected to proton nuclear magnetic resonance spectroscopy (NMR 1H). 1 Characterized by 1H NMR and high-resolution mass spectrometry (HRMS): 1 HNMR(500MHz, CDCl3)δ9.25(d,J=3.7Hz,2H),9.12(d,J=2.5Hz,1H),8.51(s, 1H),8.47(s,1H),8.27(dd,J=10.0,2.1Hz,2H),8.17(d,J=2.4Hz,2H),8.03-7 .97(m,4H),7.73(m,J=7.9,1.2Hz,1H),7.55(m,J=8.5,1.6Hz,1H),7.40(dd, J=7.8,2.1Hz,2H),7.32(d,J=7.7Hz,2H),1.36(s,18H),1.35(s,18H); HRMS(C 61 H 55 N3+H + ):m / z829.4421[M+H + ,calcd 829.4421].

[0078] Example 9

[0079] This embodiment operates the same as Example 1, except that in S1, the added dibromo-substituted aromatic ring compound is 1,2-dibromonaphthalene, and the amount of 1,2-dibromonaphthalene is 1.62 mmol. The amounts of 2,11-di-tert-butyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)indol[3,2,1-jk]carbazole, potassium carbonate, and tetra(triphenylphosphine)palladium added are 3.4 mmol, 32 mmol, and 0.13 mmol, respectively, and the intermediate product obtained is o-DtBuICz-12Na. In S2, the final product obtained is DtBuICz-12Na-c, with a yield of 60%.

[0080] The preparation route is as follows:

[0081]

[0082] The final product DtBuICz-12Na-c prepared in Example 9 was subjected to 1H NMR spectroscopy (NMR spectroscopy). 1 Characterized by 1H NMR and high-resolution mass spectrometry (HRMS): 1 H NMR (500MHz, CDCl3) δ9.17(d,J=10.0Hz,2H),8.49-8.46(m,2H),8.43(s,1H),8.27(m,J=2.1Hz,2H),8.17-8.14(m,3H ),8.01-7.97(m,4H),7.56-7.53(m,2H),7.40(dd,J=7.9,2.2Hz,2H),7.33(s,2H),1.36(s,18H),1.35(s,18H); HRMS(C 62 H 56 N2+H + ):m / z 828.4410[M+H + ,calcd 828.4410].

[0083] Example 10

[0084] This embodiment operates the same as Example 1, except that in S1, the added dibromo-substituted aromatic ring compound is 3,4-dibromofuran, and the amount of 3,4-dibromofuran is 1.27 mmol. The amounts of 2,11-di-tert-butyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)indol[3,2,1-jk]carbazole, potassium carbonate, and tetra(triphenylphosphine)palladium added are 2.67 mmol, 25 mmol, and 0.11 mmol, respectively, and the intermediate product obtained is o-DtBuICz-34FR. In S2, the final product obtained is DtBuICz-34FR-c, with a yield of 60%.

[0085] The preparation route is as follows:

[0086]

[0087] The final product DtBuICz-34FR-c prepared in Example 10 was subjected to proton nuclear magnetic resonance spectroscopy (NMR spectroscopy). 1 Characterized by 1H NMR and high-resolution mass spectrometry (HRMS): 1 H NMR (500MHz, CDCl3) δ9.20 (s, 2H), 8.54 (s, 2H), 8.43 (s, 2H), 8.26 (d, J = 2.2Hz, 2H), 8.17 (d, J = 1.9Hz, 2H), 7 .98(d,J=2.2Hz,2H),7.40(dd,J=7.7,2.1Hz,2H),7.32(d,J=7.6Hz,2H),1.36(s,18H),1.35(s,18H); HRMS(C 56 H 52 N2O + H + ):m / z 768.4110[M+H + ,calcd 768.4110].

[0088] Example 11

[0089] This embodiment operates the same as Example 1, except that in S1, the added dibromo-substituted aromatic ring compound is 3,4-dibromothiophene, and the amount of 3,4-dibromothiophene is 1.84 mmol. The amounts of 2,11-di-tert-butyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)indol[3,2,1-jk]carbazole, potassium carbonate, and tetra(triphenylphosphine)palladium added are 3.86 mmol, 37 mmol, and 0.15 mmol, respectively, and the intermediate product obtained is o-DtBuICz-34TP. In S2, the final product obtained is DtBuICz-34TP-c, with a yield of 55%.

[0090] The preparation route is as follows:

[0091]

[0092]

[0093] The final product DtBuICz-34TP-c prepared in Example 11 was subjected to proton nuclear magnetic resonance spectroscopy (NMR 1H). 1 Characterized by 1H NMR and high-resolution mass spectrometry (HRMS): 1H NMR (500MHz, CDCl3) δ9.13(s,2H),8.56(s,2H),8.26(d,J=2.2Hz,2H),8.17(d,J=1.9Hz,2H),7.98(d,J=2.2 Hz,2H),7.67(s,2H),7.40(dd,J=7.7,2.1Hz,2H),7.32(d,J=7.6Hz,2H),1.36(s,18H),1.35(s,18H); 56 H 52 N2S+H + ):m / z784.3911[M+H + ,calcd 784.3911].

[0094] Example 12

[0095] This embodiment operates the same as Example 1, except that in S1, the added dibromo-substituted aromatic ring compound is 2,3-dibromofuran, and the amount of 2,3-dibromofuran is 1.27 mmol. The amounts of 2,11-di-tert-butyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)indol[3,2,1-jk]carbazole, potassium carbonate, and tetra(triphenylphosphine)palladium added are 2.67 mmol, 25 mmol, and 0.11 mmol, respectively, and the intermediate product obtained is o-DtBuICz-23FR. In S2, the final product obtained is DtBuICz-23FR-c, with a yield of 60%.

[0096] The preparation route is as follows:

[0097]

[0098] The final product DtBuICz-23FR-c prepared in Example 12 was subjected to proton nuclear magnetic resonance spectroscopy (NMR 1H). 1 Characterized by 1H NMR and high-resolution mass spectrometry (HRMS): 1 H NMR (500MHz, CDCl3) δ9.20(s,1H),9.06(s,1H),8.69(s,1H),8.46(s,1H),8.25(dd,J=8.9,2.1Hz,2H),8.17(d,J=2.4Hz,2H),7.98(d,J=2.3 HRMS (C) 56 H52 N2O + H + ):m / z 768.4115[M+H + ,calcd768.4115].

[0099] Example 13

[0100] This embodiment operates the same as Example 1, except that in S1, the added dibromo-substituted aromatic ring compound is 2,3-dibromothiophene, and the amount of 2,3-dibromothiophene is 1.84 mmol. The amounts of 2,11-di-tert-butyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)indol[3,2,1-jk]carbazole, potassium carbonate, and tetra(triphenylphosphine)palladium added are 3.86 mmol, 37 mmol, and 0.15 mmol, respectively, and the intermediate product obtained is o-DtBuICz-23TP. In S2, the final product obtained is DtBuICz-23TP-c, with a yield of 55%.

[0101] The preparation route is as follows:

[0102]

[0103] The final product DtBuICz-23TP-c prepared in Example 13 was subjected to proton nuclear magnetic resonance spectroscopy (NMR 1H). 1 Characterized by 1H NMR and high-resolution mass spectrometry (HRMS): 1 H NMR (500MHz, CDCl3) δ9.13(s,1H),9.08(s,1H),8.56(s,1H),8.48(s,1H),8.26(dd,J=4.8,2.1Hz,2H),8.17(d,J=2.4Hz,2H),8.05(d,J=5.5 HRMS (C) 56 H 52 N2S+H + ):m / z 784.3926[M+H + ,calcd784.3926].

[0104] Example 14

[0105] This embodiment operates the same as Example 1, except that in S1, the added dibromo-substituted aromatic ring compound is 6,7-dibromoquinoxaline, and the amount of 6,7-dibromoquinoxaline is 1.58 mmol. The amounts of 2,11-di-tert-butyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)indol[3,2,1-jk]carbazole, potassium carbonate, and tetra(triphenylphosphine)palladium added are 3.32 mmol, 32 mmol, and 0.13 mmol, respectively, and the resulting intermediate product is o-DtBuICz-67qol. In S2, the final product obtained is DtBuICz-67qol-c, with a yield of 40%.

[0106] The preparation route is as follows:

[0107]

[0108] The final product DtBuICz-67qol-c prepared in Example 14 was subjected to proton nuclear magnetic resonance spectroscopy (NMR 1H). 1 Characterized by 1H NMR and high-resolution mass spectrometry (HRMS): 1 H NMR (500MHz, CDCl3) δ9.25(s,2H),9.22(s,2H),8.49(s,2H),8.30(s,2H),8.26(d,J=2.2Hz,2H),8.17(d,J=1.9Hz, 2H),7.98(d,J=2.2Hz,2H),7.40(dd,J=7.7,2.1Hz,2H),7.32(d,J=7.6Hz,2H),1.36(s,18H),1.35(s,18H); HRMS(C 60 H 54 N4+H + ):m / z 830.4316[M+H + ,calcd 830.4316].

[0109] Example 15

[0110] This embodiment operates the same as Example 1, except that in S1, the added dibromo-substituted aromatic ring compound is 2,3-dibromoquinoxaline, and the amount of 2,3-dibromoquinoxaline is 1.44 mmol. The amounts of 2,11-di-tert-butyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)indol[3,2,1-jk]carbazole, potassium carbonate, and tetra(triphenylphosphine)palladium added are 3.02 mmol, 29 mmol, and 0.12 mmol, respectively, and the resulting intermediate product is o-DtBuICz-23qol. In S2, the final product obtained is DtBuICz-23qol-c, with a yield of 40%.

[0111] The preparation route is as follows:

[0112]

[0113] The final product DtBuICz-23qol-c prepared in Example 15 was subjected to 1H NMR spectroscopy (NMR spectroscopy). 1 Characterized by 1H NMR and high-resolution mass spectrometry (HRMS): 1 H NMR (500MHz, CDCl3) δ9.32(s,2H),8.56(s,2H),8.28(d,J=2.2Hz,2H),8.17(d,J=1.9Hz,2H),8.10(dd,J=6.1,3.4Hz,2H),7.98(d, HRMS(C) 60 H 54 N4+H + ):m / z 830.4317[M+H + ,calcd 830.4317].

[0114] Example 16

[0115] This embodiment operates the same as Example 1, except that in S1, the added dibromo-substituted aromatic ring compound is 4,5-dibromophthalonitrile, and the amount of 4,5-dibromophthalonitrile is 1.58 mmol. The amounts of 2,11-di-tert-butyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)indol[3,2,1-jk]carbazole, potassium carbonate, and tetra(triphenylphosphine)palladium added are 3.32 mmol, 32 mmol, and 0.126 mmol, respectively, and the resulting intermediate product is o-DtBuICz-PDCN. In S2, the final product obtained is DtBuICz-PDCN-c, with a yield of 60%.

[0116] The preparation route is as follows:

[0117]

[0118]

[0119] The final product DtBuICz-PDCN-c prepared in Example 16 was subjected to proton nuclear magnetic resonance spectroscopy (NMR spectroscopy). 1 Characterized by 1H NMR and high-resolution mass spectrometry (HRMS): 1 H NMR (500MHz, CDCl3) δ9.20 (s, 2H), 8.99 (s, 2H), 8.49 (s, 2H), 8.26 (d, J = 2.2Hz, 2H), 8.17 (d, J = 1.9Hz, 2H), 7 .98(d,J=2.2Hz,2H),7.40(dd,J=7.7,2.1Hz,2H),7.32(d,J=7.6Hz,2H),1.36(s,18H),1.35(s,18H); HRMS(C 60 H 52 N4+H + ):m / z828.4217[M+H + ,calcd 828.4217].

[0120] Example 17

[0121] This embodiment operates the same as Example 1, except that: in S1, the borate ester of the added indolocarbazole or indolocarbazole derivative is 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)indolo[3,2,1-jk]carbazole, with a molar amount of 2.92 mmol, and the intermediate product obtained is o-DICz-Ph; in S2, the final product obtained is DICz-Ph-c, with a yield of 70%.

[0122] The preparation route is as follows:

[0123]

[0124]

[0125] The final product DICz-Ph-c prepared in Example 17 was subjected to proton nuclear magnetic resonance spectroscopy (NMR 1H). 1 Characterized by 1H NMR and high-resolution mass spectrometry (HRMS): 1 HNMR(500MHz, CDCl3)δ9.04(s,2H),8.51(s,2H),8.26-8.21(m,4H),8.17-8.13(m,4H),7.68(dd, HRMS(C) 42 H 22 N2+H + ):m / z 554.1805[M+H + ,calcd 554.1805].

[0126] Example 18

[0127] This embodiment operates in the same manner as Example 1, except that: in S1, the borate ester of the added indolocarbazole or indolocarbazole derivative is 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)indol[3,2,1-jk]carbazole, with a molar amount of 2.92 mmol; the added dibromo-substituted aromatic ring compound is 2,3-dibromonaphthalene, with a molar amount of 1.71 mmol; and the added potassium carbonate and tetra(triphenylphosphine)palladium have molar amounts of 34 mmol and 0.137 mmol, respectively, resulting in an intermediate product of o-DICz-23Na; in S2, the final product obtained is DICz-23Na-c, with a yield of 70%.

[0128] The preparation route is as follows:

[0129]

[0130] The final product DICz-23Na-c prepared in Example 18 was subjected to 1H NMR spectroscopy (NMR spectroscopy). 1 Characterized by 1H NMR and high-resolution mass spectrometry (HRMS): 1H NMR (500MHz, CDCl3) δ9.10 (d, J = 2.4Hz, 2H), 9.07 (s, 2H), 8.49 (s, 2H), 8.27-8.21 (m, 4H), 8.17-8.14 (m, 2H), 8.04-8.00 ( m,2H),7.68(dd,J=6.3,1.6Hz,2H),7.55-7.51(m,4H),7.38(m,J=7.4,6.4,1.3Hz,2H),7.31(m,J=7.5,1.5Hz,2H); HRMS(C 46 H 24 N2+H + ):m / z 604.1921[M+H + ,calcd604.1921).

[0131] The final product DtBuICz-Ph-c obtained in Example 1 was used as a light-emitting material to prepare a doped device, denoted as DtBuICz-Ph-c device. The structure of the device is: ITO / HATC N / TAPC / TcTa / mCP / DtBuICz-Ph-c:mCPBC / PPF / TmPyPb / LiF / Al.

[0132] The wavelength distribution of emission from the DtBuICz-Ph-c device under electric field driving was recorded using an electroluminescence spectrometer. The results are as follows: Figure 1 As shown, from Figure 1 As can be seen from the data, the maximum emission peak of the electroluminescence spectrum of the DtBuICz-Ph-c device is 434 nm, and the full width at half maximum (FWHM) is only 17 nm.

[0133] The relationship between the brightness, voltage, and current density of a DtBuICz-Ph-c device was tested using a silicon photodiode, and the results are as follows: Figure 2 As shown, from Figure 2 It can be seen from this that the maximum luminance of the DtBuICz-Ph-c device is 4000 cd / m². 2 The starting voltage is 4.2V.

[0134] The external quantum efficiency-luminosity dependence of the DtBuICz-Ph-c device was tested using a silicon photodiode, and the results are as follows: Figure 3 As shown, from Figure 3 As can be seen, the maximum external quantum efficiency of the DtBuICz-Ph-c device is 4.68%.

[0135] The final product DtBuICz-PCN-c obtained in Example 2 was used as a light-emitting material to prepare a doped device, denoted as DtBuICz-PCN-c device. The structure of the device is: ITO / HATCN / TAPC / TcTa / mCP / DtBuICz-PCN-c:mCPBC / PPF / TmPyPb / LiF / Al.

[0136] The wavelength distribution of emission from the DtBuICz-PCN-c device under electric field driving was recorded using an electroluminescence spectrometer. The results are as follows: Figure 4 As shown, from Figure 4 As can be seen from the data, the maximum emission peak of the electroluminescence spectrum of the DtBuICz-PCN-c device is 432 nm, and the full width at half maximum (FWHM) is only 19 nm.

[0137] The relationship between the brightness, voltage, and current density of a DtBuICz-PCN-c device was tested using a silicon photodiode, and the results are as follows: Figure 5 As shown, from Figure 5 As can be seen from this, the maximum luminance of the DtBuICz-PCN-c device is 4613 cd / m². 2 The starting voltage is 4.2V.

[0138] The external quantum efficiency-luminosity dependence of the DtBuICz-PCN-c device was tested using a silicon photodiode, and the results are as follows: Figure 6 As shown, from Figure 6 As can be seen, the maximum external quantum efficiency of the DtBuICz-PCN-c device is 4.86%.

[0139] Therefore, the present invention employs the above-mentioned organic electroluminescent material based on indole-carbazole and its derivatives with intramolecular cyclic closure, its preparation method and application. This material can achieve narrow spectrum emission and high exciton utilization, and has excellent electroluminescence performance. It can be widely used in fields such as organic electroluminescence. At the same time, the preparation method of this organic electroluminescent material is simple and the raw materials are readily available.

[0140] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. An organic electroluminescent material based on intramolecular cyclic closure constructed from indolecarbazole and its derivatives, characterized in that: The structural formula of the organic electroluminescent material is: Wherein, A includes substituted or unsubstituted benzene rings, and substituted or unsubstituted C rings. 10 -C 50 fused aromatic rings and substituted or unsubstituted C4-C 50 One of the fused heterocycles, R1 includes H, C1-C 12 Alkyl, C1-C 12 Alkoxy, C6-C 18 Aryl and C5-C 18 One of the heteroaryl groups, where R2 includes H, C1-C 12 Alkyl, C1-C 12 Alkoxy, C6-C 18 Aryl and C5-C 18 One of the heteroaryl groups, where R3 includes H, C1-C 12 Alkyl, C1-C 12 Alkoxy, C6-C 18 Aryl and C5-C 18 One of the heteroaryl groups, where R4 includes H, C1-C 12 Alkyl, C1-C 12 Alkoxy, C6-C 18 Aryl and C5-C 18 One of the heteroaryl groups.

2. The organic electroluminescent material based on intramolecular cyclic closure constructed from indolecarbazole and its derivatives according to claim 1, characterized in that: C with or without substitution 10 -C 50 The fused aromatic ring includes one of a substituted or unsubstituted naphthalene ring, a substituted or unsubstituted anthracene ring, and a substituted or unsubstituted phenanthrene ring, wherein the substituted or unsubstituted C4-C ring is... 50 The fused heterocycles include one of the following: a substituted or unsubstituted furan ring, a substituted or unsubstituted thiophene ring, and a substituted or unsubstituted six-membered heteroaromatic ring containing 1-2 N atoms.

3. The organic electroluminescent material based on intramolecular cyclic closure constructed from indolecarbazole and its derivatives according to claim 1, characterized in that: A is linked to indole-carbazole or an indole-carbazole derivative in an ortho position, and after linkage, intramolecular ring closure is performed to form a six-membered ring.

4. The organic electroluminescent material based on intramolecular cyclic closure constructed from indolecarbazole and its derivatives according to claim 1, characterized in that: The structural formula for A includes one of 1-44: R' includes H, substituted or unsubstituted benzene rings, C1-C 12 Alkyl, C1-C 12 alkoxy, substituted or unsubstituted C6-C 18 Aryl and C5-C 18 One of the heteroaryl groups, where "R" includes H, a substituted or unsubstituted benzene ring, and C1-C2. 12 Alkyl, C1-C 12 alkoxy, substituted or unsubstituted C6-C 18 Aryl and C5-C 18 One of the heteroaryl groups, where R”' includes H, a substituted or unsubstituted benzene ring, and C1-C2. 12 Alkyl, C1-C 12 alkoxy, substituted or unsubstituted C6-C 18 Aryl and C5-C 18 One of the heteroaryl groups, where R"" includes H, a substituted or unsubstituted benzene ring, and C1-C2. 12 Alkyl, C1-C 12 alkoxy, substituted or unsubstituted C6-C 18 Aryl and C5-C 18 One of the heteroaryl groups, This indicates that it is partially linked to indobenzocarbazole or an indobenzocarbazole derivative.

5. The organic electroluminescent material based on intramolecular cyclic closure constructed from indole-carbazole and its derivatives according to claim 4, characterized in that: Indolocarbazole and its derivatives are electron-donating groups, with A and the benzene rings of indolocarbazole on both sides forming a conjugated planar center.

6. A method for preparing an organic electroluminescent material based on intramolecular cyclic closure constructed from indolecarbazole and its derivatives, as described in any one of claims 1-5, characterized in that: Includes the following steps: S1. Using dibromo-substituted aromatic ring compounds, indole-carbazole or indole-carbazole derivatives as raw materials, a mixed solvent is added under alkaline conditions and a catalyst, and the reaction is heated to obtain an intermediate product containing indole-carbazole or indole-carbazole derivatives. The intermediates obtained in S2 and S1 are reacted with solvent and catalyst to obtain an organic electroluminescent material containing intramolecular cyclization of indole-carbazole or indole-carbazole derivatives.

7. The method for preparing an organic electroluminescent material based on intramolecular cyclic closure constructed from indolecarbazole and its derivatives according to claim 6, characterized in that: In S1, dibromo-substituted aromatic ring compounds include 1,2-dibromobenzene, 2,3-dibromonaphthalene, 9,10-dibromophenanthrene, 3,4-dibromobenzonitrile, 1,2-dibromo-4-tert-butylbenzene, 3,4-dibromopyridine, 2,3-dibromopyrazine, 2,3-dibromoquinoline, 1,2-dibromonaphthalene, 3,4-dibromofuran, 3,4-dibromothiophene, 2,3-dibromofuran, 2,3-dibromothiophene, 6,7-dibromoquinoxaline, 2,3-dibromoquinoxaline, or 4,5-dibromophthalamide. The nitriles, indolocarbazole or indolocarbazole derivatives of which are borate esters including 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)indol[3,2,1-jk]carbazole or 2,11-di-tert-butyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)indol[3,2,1-jk]carbazole, are basic substances including potassium carbonate, sodium carbonate or sodium hydroxide, the catalyst is tetra(triphenylphosphine)palladium, and the mixed solvent is toluene, ethanol and water.

8. The method for preparing an organic electroluminescent material based on intramolecular cyclic closure constructed from indolecarbazole and its derivatives according to claim 7, characterized in that: In S1, the molar ratio of dibromo-substituted aromatic ring compounds to indolocarbazole or its derivative borate esters is 1:1.8-2.5, the molar ratio of basic substances to catalyst is 20:0.05-0.1, the volume ratio of toluene, ethanol and water is 4-8:1-3:1, the reaction temperature is 80-120℃, and the reaction time is 4-8h.

9. The method for preparing an organic electroluminescent material based on intramolecular cyclic closure constructed from indolecarbazole and its derivatives according to claim 6, characterized in that: In S2, the solvent is dichloromethane, the catalysts are anhydrous ferric chloride and nitromethane, the molar ratio of intermediate product to anhydrous ferric chloride is 1:8-12, the volume ratio of nitromethane to dichloromethane is 1:0.5-2, the reaction temperature is 0-3℃, and the reaction time is 0.5-2h.

10. An application of an intramolecularly cyclic-closed organic electroluminescent material based on indolecarbazole and its derivatives, characterized in that: The organic electroluminescent material based on indole-carbazole and its derivatives, as described in any one of claims 1-5, is used as the light-emitting layer guest in the fabrication of organic electroluminescent devices, either doped or undoped.

Images