An organic light-emitting thin film material and an organic electroluminescent device

Abstract

The present application provides an organic light-emitting thin film material and an organic electroluminescent device, the light-emitting thin film material contains a structure shown in formula I and formula II, the light-emitting thin film material has narrow spectrum light-emitting characteristics, as a narrow spectrum light-emitting thin film material for preparing a light-emitting layer of an organic electroluminescent device, the organic electroluminescent device prepared thereby realizes narrow spectrum emission, the half peak width is less than 40 nm, and makes the highest electroluminescent external quantum efficiency of the device be as high as more than 30%, and has a higher device lifetime.

Description

Technical Field

[0001] This invention belongs to the field of organic electroluminescence technology, and relates to an organic light-emitting thin film material and an organic electroluminescence device. Background Technology

[0002] Organic optoelectronic materials are a class of organic materials that possess properties such as the generation, conversion, and transmission of photons and electrons. Currently, the controllable optoelectronic properties of organic optoelectronic materials have been applied to organic light-emitting diodes (OLEDs), organic photovoltaics (OPVs), organic field-effect transistors (OFETs), and even organic lasers. In recent years, OLEDs have become a very popular new type of flat panel display product both domestically and internationally. OLED displays feature self-emissive characteristics, wide viewing angle, short response time, high luminous efficiency, wide color gamut, low operating voltage, thin panels, the ability to manufacture large-size flexible panels, and low cost, earning them the reputation as the star flat panel display product of the 21st century.

[0003] The history of organic electroluminescence can be traced back to the report by Bernanose et al. in 1953 (Holst GA, Kster T, Voges E, et al. FLOX—an oxygen-flux-measuring system using a phase-modulation method to evaluate the oxygen-dependent fluorescence lifetime, ScienceDirect. Sensors and Actuators B: Chemical, 1995, 29, 213.). About 10 years later, in 1963, Pope et al. of New York University observed the fluorescence emission of anthracene by applying a voltage to anthracene crystals (M. Pope, H. Kallmann and P. Magnante, Electroluminescence in Organic Crystals, J. Chem. Phys., 1963, 38, 2042). In 1987, CWTang et al. of Kodak Corporation in the United States used ultrathin film technology, employing aromatic amines with good hole transport performance as the hole transport layer, an aluminum complex of 8-hydroxyquinoline as the light-emitting layer, and indium tin oxide (ITO) thin film and a metal alloy as the anode and cathode, respectively, to fabricate a light-emitting device. This device achieved a brightness of 1000 cd / m² at a driving voltage of 10V.2 The green light emission of the device, with an efficiency of 1.5 lm / W (CWTang and S.A. Van Slyke, Organic electroluminescent diodes, Appl. Phys. Lett., 1987, 51, 913), was a breakthrough that led to the rapid and in-depth development of organic electroluminescence research worldwide. In 1990, Burroughes et al. of Cambridge University proposed the first light-emitting diode based on polymer (PPV). This showed that PPV, in monolayer devices, can serve as a highly fluorescent emitting material with high luminous efficiency (Burroughes J He et al., Light-emitting diodes based on conjugated polymers, Nature, 1990, 347, 539). In 1998, Baldo and Forrest et al. from Princeton University reported the first phosphorescent device based on electroluminescence, which in principle could have 100% internal quantum yield (MA Baldo, DFO' Brinetal., Highly efficient phosphorescent emission from organic electroluminescent devices, Nature, 1998, 395, 151). However, on the one hand, phosphorescent materials generally use precious metals such as iridium and platinum, which are expensive. On the other hand, deep blue phosphorescent materials still have chemical instability and large efficiency roll-off problems at high current densities. Therefore, it is extremely important to develop an OLED device that can achieve high-efficiency light emission using inexpensive and stable small organic molecule materials.

[0004] In 2012, the Adachi research group at Kyushu University reported a highly efficient all-fluorescent OLED device based on the thermally activated delayed fluorescence (TADF) mechanism (Uoyama H, Goushi K, Shizu K, et al. Highly efficient organic light-emitting diodes from delayed fluorescence, Nature, 2012, 492(7428):234-238.). When the energy difference between the S1 and T1 levels of a molecule is sufficiently small, the triplet exciton can absorb thermal energy, return to the singlet state through a RISC process, and then emit fluorescence. Theoretically, the internal quantum efficiency (IQE) of this device can reach 100%, and the external quantum efficiency (EQE) can even reach 30%, comparable to the level of phosphorescent devices. As a next-generation light-emitting material, research on TADF materials is booming.

[0005] TADF molecules are mainly used as guest materials to dope in wide-bandgap host materials to achieve high-efficiency thermally activated delayed fluorescence (Q. Zhang, J. Li, K. Shizu, et al. Design of Efficient Thermally Activated Delayed Fluorescence Materials for Pure Blue Organic Light Emitting Diodes, J. Am. Chem. Soc. 2012, 134, 14706; H. Uoyama, K. Goushi, K. Shizu, H. Nomura, C. Adachi, Highly efficient organic light-emitting diodes from delayed fluorescence, Nature, 2012, 492, 234; T. Nishimoto, T. Yasuda, et al. A six-carbazole-decorated cyclophosphazene as a host with high triplet energy to realize efficient delayed-fluorescence OLEDs, Mater. Horiz. 2014, 1, 264). Unlike traditional localized (LE) state luminescence in fluorescent molecules, TADF emission primarily originates from transitions in the ICT state. Therefore, it is easily affected by vibrational and rotational motions between the donor and acceptor, resulting in a broader spectrum and a longer delayed fluorescence excitation lifetime. Consequently, electroluminescent devices based on TADF luminescent materials exhibit poor stability. Although pure organic TADF luminescent materials eliminate dependence on noble metals and offer the advantage of low cost, their poor emission spectral color purity and stability remain major challenges. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide an organic light-emitting thin film material and an organic electroluminescent device. The organic light-emitting thin film material provided by the present invention aims to overcome the defects of TADF light-emitting molecules, providing a light-emitting material with a narrow emission spectrum and good stability, used to prepare the light-emitting layer of an organic electroluminescent device, thereby enabling the organic electroluminescent device to exhibit excellent characteristics.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] On one hand, the present invention provides an organic light-emitting thin film material, the organic light-emitting thin film material comprising a dopant material and a host material, wherein the dopant material is a boron-nitrogen compound having the following formula I or formula II:

[0009]

[0010] R is selected from the groups shown in formula R-1, R-2, R-3, or R-4:

[0011]

[0012] R CZ Selected from 5- to 18-membered heteroaryl groups, with one or more R groups 0 Substituted 5- to 18-membered heteroaryl, diphenylamino, or substituted with one or more R 0 Substituted diphenylamine group;

[0013] R 01 and R 02 Independently selected from H, deuterium, C1-C20 alkyl, C1-C20 alkoxy, C3-C10 cycloalkyl, C6-C18 aryl, and dominated by one or more R 0 Substituted C6-C18 aryl, 5- to 18-heteroaryl, and substituted with one or more R 0 Substituted 5- to 18-membered heteroaryl, diphenylamino, or substituted with one or more R 0 Substituted diphenylamine group;

[0014] R 0 Each time it appears, it is independently deuterium, fluorine, C1-C12 alkyl, C1-C12 alkoxy, C3-C12 cycloalkyl, C6-C14 aryl, 5- to 18-membered heteroaryl or diphenylamino;

[0015] R 1 R 2 R 3 R 4 R 5 R 6 R 7 and R 8 Independently selected from H, deuterium, C1-C20 alkyl, C1-C20 alkoxy, C3-C10 cycloalkyl, C6-C18 aryl, and dominated by one or more R a Substituted C6-C18 aryl, 5- to 18-heteroaryl, and substituted with one or more R a Substituted 5- to 18-membered heteroaryl, diphenylamino, or substituted with one or more R a The substituted diphenylamine group, and R 1 and R 8 R 2 and R7 R 3 and R 6 Or R 4 and R 5 In at least one of the four pairs of substituent groups, the two substituents in one pair are different;

[0016] R a Each occurrence is independently of deuterium, fluorine, CN, C1-C12 alkyl, C1-C12 alkoxy, C3-C12 cycloalkyl, C6-C14 aryl, and is accompanied by one or more R. b Substituted C6-C14 aryl, 5- to 18-membered heteroaryl, and substituted with one or more R b Substituted 5- to 18-membered heteroaryl, diphenylamino, or substituted with one or more R b Substituted diphenylamine group;

[0017] R b Each occurrence is independently of deuterium, fluorine, CN, C1-C12 alkyl, C1-C12 alkoxy, C3-C10 cycloalkyl, C6-C14 aryl, and is accompanied by one or more R. c Substituted C6-C14 aryl, 5- to 18-membered heteroaryl, and substituted with one or more R c Substituted 5- to 18-membered heteroaryl, diphenylamino, or substituted with one or more R c Substituted diphenylamine group;

[0018] R c Each occurrence is independently of deuterium, fluorine, CN, C1-C12 alkyl, C1-C12 alkoxy, C3-C10 cycloalkyl, C6-C14 aryl, and is accompanied by one or more R. d Substituted C6-C14 aryl, 5- to 18-membered heteroaryl, and substituted with one or more R d Substituted 5- to 18-membered heteroaryl, diphenylamino, or substituted with one or more R d Substituted diphenylamine group;

[0019] R d Each time it appears, it is independently deuterium, fluorine, C1-C12 alkyl, C1-C12 alkoxy, C3-C10 cycloalkyl, C6-C14 aryl, or is affected by one or more R groups. e Substituted C6-C14 aryl groups;

[0020] R e Each time it appears, it is independently deuterium, fluorine, C1-C12 alkyl, C1-C12 alkoxy, C3-C10 cycloalkyl, or C6-C14 aryl;

[0021] R 1 R 2 R 3R 4 R 5 R 6 R 7 and R 8 Independent existence or R 1 R 2 R 3 R 4 R 5 R 6 R 7 and R 8 At least one of them forms a ring with the connected aromatic ring;

[0022] The alkyl, alkoxy, cycloalkyl, aryl, and heteroaryl groups are optionally substituted with one or more substituents selected from the following: halogen, -CN, C1-C12 alkyl, C1-C12 alkoxy, C1-C12 haloalkyl, C3-C10 cycloalkyl, C6-C14 aryl, and 5- to 18-membered heteroaryl.

[0023] Preferably, the R a Each occurrence is independent of deuterium, fluorine, and C1-C2. 12 Alkyl, C1-C 12 Alkoxy, C3-C 10 cycloalkyl, with at least one C1-C 12 Alkyl-substituted phenyl, with at least one C1-C 12 Alkoxy-substituted phenyl, phenyl-C1~C 12 Alkyl, diphenylamino, with at least one C1-C 12 Alkyl-substituted diphenylamino group, carbazole group, or group with at least one C1-C 12 Alkyl-substituted carbazole group;

[0024] Preferably, the R b Each occurrence is independent of deuterium, fluorine, and C1-C2. 12 Alkyl, C1-C 12 Alkoxy, C3-C 10 cycloalkyl, with at least one C1-C 12 Alkyl-substituted phenyl, with at least one C1-C 12 Alkoxy-substituted phenyl, phenyl-C1~C 12 Alkyl, diphenylamino, with at least one C1-C 12 Alkyl-substituted diphenylamino group, carbazole group, or group with at least one C1-C 12 Alkyl-substituted carbazole group;

[0025] Preferably, the R c Each occurrence is independent of deuterium, fluorine, and C1-C2. 12 Alkyl, C1-C 12Alkoxy, C3-C 10 cycloalkyl, with at least one C1-C 12 Alkyl-substituted phenyl, with at least one C1-C 12 Alkoxy-substituted phenyl, phenyl-C1~C 12 Alkyl, diphenylamino, with at least one C1-C 12 Alkyl-substituted diphenylamino group, carbazole group, or group with at least one C1-C 12 Alkyl-substituted carbazole group;

[0026] Preferably, the R d Each occurrence is independent of deuterium, fluorine, and C1-C2. 12 Alkyl, C1-C 12 Alkoxy, C3-C 10 cycloalkyl, with at least one C1-C 12 Alkyl-substituted phenyl, with at least one C1-C 12 Alkoxy-substituted phenyl, carbazole, or alkyl-substituted phenyl groups with at least one C1-C bond 12 Alkyl-substituted carbazole group;

[0027] Preferably, the R 1 R 2 R 3 R 4 R 5 R 6 R 7 and R 8 Independently, it is ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, hexyl, octyl, decyl, Methoxy, ethoxy, butoxy, hexoxy Cyclohexyl, adamantyl, phenyl, 2-methyl-phenyl, 4-methyl-phenyl, 4-ethyl-phenyl, 4-propyl-phenyl, 4-isopropylphenyl, 4-n-butylphenyl

[0028]

[0029]

[0030] The wavy lines represent the connection sites of the functional groups.

[0031] Preferably, the R 1 R 2 R 3 R 4 R 5 R 6 R 7 and R 8 Independently 2-methyl-phenyl, phenyl,

[0032] The wavy lines represent the connection sites of the functional groups;

[0033] Preferably, R 1 R 2 R 3 R 4 R 5 R 6 R 7 and R 8 At least one of them forms a ring structure with the connected aromatic ring as follows:

[0034] The bond marked with an asterisk (*) is a bond shared with the aromatic ring.

[0035] Preferably, R is selected from

[0036] Preferably, the boron-nitrogen compound is any one of the following compounds:

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051] Preferably, the host material includes a first host material and a second host material, wherein the first host material includes any one of the compounds shown in formulas H-1 to H-10; and the second host material includes any one of the compounds shown in formulas Ph-2CN-1 to Ph-2CN-6.

[0052]

[0053] Where X1, Y1, and Z1 are CH or N, and at most one of X1, Y1, and Z1 is N; where R 1H and R 2H Independently, it can be any of the following groups:

[0054]

[0055]

[0056] Where X2, Y2, and Z2 are CH or N, and at most one of X2, Y2, and Z2 is N;

[0057] Where R aH and R bH Independent of H, C1-C 20 Alkyl, C1-C 20 Alkoxy, C6-C 20 Aryl, C1-C 20 Alkyl-substituted C6-C 20 Aryl or C1-C 20 Alkoxy-substituted C6-C 20 Aryl group, * indicates the linkage site of the group;

[0058] W 1 W 2 W 3 W 4 W 5 W 6 W 7 W 8 and W 9 Independently S or O;

[0059] R 3H R 4H R 5H R 6H R 7H R 8H R 9H R 10H R 11H R 12H R 13H and R 14H It is independently H, deuterium, C1-C6 alkyl or C6-C24 aryl;

[0060]

[0061] Y1, Y2, Y3, Y4, Y5, Y6, Y7 and Y8 are independently O (oxygen) or S (sulfur);

[0062] R s1 R s2 R s3 R s4 R s5 and R s6 It is independently C6-C24 aryl or C12-C36 heteroaryl;

[0063] R si (i=7-39) are independently H, deuterium, C1-C6 alkyl, C1-C6 alkoxy or C6-C24 aryl.

[0064] Preferably, the weight ratio between the first main material and the second main material is 1:20 to 20:1, such as 1:20, 1:19, 1:18, 1:16, 1:14, 1:12, 1:10, 1:8, 1:6, 1:4, 1:2, 1:1, 2:1, 4:1, 6:1, 8:1, 10:1, 12:1, 15:1, 18:1, 19:1 or 20:1, etc.

[0065] Preferably, R s1 R s2 R s3 R s4 R s5 and R s6 Independently selected from any one of the following 24 groups:

[0066]

[0067]

[0068] An asterisk (*) represents a linking site of a functional group.

[0069] Preferably, R si (i = 7-39) Independently selected from any one of the following 5 groups:

[0070] An asterisk (*) represents the linking site of a functional group.

[0071] Preferably, the first host material is any one of the following compounds H1-1 to H1-254:

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083] Preferably, the second host material is any one of compounds from 2CN-1 to 2CN-60:

[0084]

[0085]

[0086]

[0087] In some embodiments of the present invention, the doping material in the organic light-emitting thin film material is a boron nitrogen compound of formula I and formula II, and the composition of the host material includes the following three cases: (1) any one of the compounds shown in formulas H-1 to H-10 and any one of the compounds shown in formulas 2CN-1 to 2CN-60; (2) any one of the compounds shown in formulas H1-1 to H1-254 and any one of the compounds shown in formulas Ph-2CN-1 to Ph-2CN-6; (3) any one of the compounds shown in formulas H1-1 to H1-254 and any one of the compounds shown in formulas 2CN-1 to 2CN-60.

[0088] Preferably, the dopant material in the organic light-emitting thin film material is a boron-nitrogen compound as described in Formula I and Formula II; the host material is composed of any one of the dicyanobenzene derivatives shown in Formula 2CN-1 to 2CN-60 and any one of the carbazole derivatives shown in Formula H1-1 to H1-254; preferably, in the host material, the weight ratio between the dicyanobenzene derivative and the carbazole derivative is 1:20 to 20:1, for example, 1:20, 1:19, 1:18, 1:16, 1:14, 1:12, 1:10, 1:8, 1:6, 1:4, 1:2, 1:1, 2:1, 4:1, 6:1, 8:1, 10:1, 12:1, 15:1, 18:1, 19:1 or 20:1, etc.

[0089] Preferably, the dopant material in the organic light-emitting thin film material is any one of the compounds shown in formulas BN-1 to BN-272, and the host material is composed of any one of the compounds shown in formulas Ph-2CN-1 to Ph-2CN-6 and any one of the compounds shown in formulas H1-1 to H1-254; preferably, in the host material, the weight ratio between the compounds shown in formulas Ph-2CN-1 to Ph-2CN-6 and the compounds shown in formulas H1-1 to H1-254 is 1:20 to 20:1, for example, 1:20, 1:19, 1:18, 1:16, 1:14, 1:12, 1:10, 1:8, 1:6, 1:4, 1:2, 1:1, 2:1, 4:1, 6:1, 8:1, 10:1, 12:1, 15:1, 18:1, 19:1 or 20:1, etc.

[0090] Preferably, the dopant material in the organic light-emitting thin film material is any one of the compounds shown in formulas BN-1 to BN-272, and the host material is composed of any one of the dicyanobenzene derivatives shown in formulas 2CN-1 to 2CN-60 and any one of the compounds shown in formulas H1-1 to H1-254; preferably, in the host material, the weight ratio between the dicyanobenzene derivatives shown in formulas 2CN-1 to 2CN-60 and the carbazole derivatives shown in formulas H1-1 to H1-254 is 1:20 to 20:1, for example, 1:20, 1:19, 1:18, 1:16, 1:14, 1:12, 1:10, 1:8, 1:6, 1:4, 1:2, 1:1, 2:1, 4:1, 6:1, 8:1, 10:1, 12:1, 15:1, 18:1, 19:1 or 20:1, etc.

[0091] Preferably, the weight ratio between the host material and the dopant material in the organic light-emitting thin film material is from 99.5:0.5 to 95.0:5.0, for example, 99.5:0.5, 99:1, 96:4, 93:7, 90:10, 85:15, 80:20, 70:30, 60:40, 50:50, 40:60, 30:70, 20:80, 15:85, 10:90, 5:95, etc.

[0092] Preferably, the host material includes a first host material, a second host material and a third host material, wherein the first host material includes any one of compounds having the structure shown in formula Trz1-A to Trz6-A, the second host material includes any one of compounds having the structure shown in formula Trz1-A to Trz6-A, and the third host material includes any one of phosphorescent compounds containing metallic Pt as shown in formula Pt-1.

[0093]

[0094] Where R 1a R 1b R 2a R 2b R 3a and R 3b One or two of them are independent as R Tz The remaining elements are, independently and identically, hydrogen, deuterium, C1-C8 alkyl, C1-C8 alkoxy, or C6-C4. 18 Aryl, C1-C8 alkyl substituted C6-C 18 Aryl or C1-C8 alkoxy-substituted C6-C 18 aryl; R Tz It can be any of the substituents shown in the following formula:

[0095]

[0096]

[0097]

[0098] The asterisk represents the bonding site of the functional group;

[0099] Preferably, the ratio of the compounds shown in Trz1-A, Trz2-A, Trz3-A, Trz4-A, Trz5-A, or Trz6-A to the compounds shown in H-1, H-2, H-3, H-4, H-5, H-6, H-7, H-8, H9, or H-10 in the main material is from 1:20 to 20:1, for example, 1:20, 1:19, 1:18, 1:16, 1:14, 1:12, 1:10, 1:8, 1:6, 1:4, 1:2, 1:1, 2:1, 4:1, 6:1, 8:1, 10:1, 12:1, 15:1, 18:1, 19:1, or 20:1.

[0100] Preferably, the weight ratio of the compound shown in Trz1-A, Trz2-A, Trz3-A, Trz4-A, Trz5-A or Trz6-A to the compound shown in H-1, H-2, H-3, H-4, H-5, H-6, H-7, H-8, H9 or H-10 to the weight of any phosphorescent compound containing metallic Pt as shown in formula Pt-1 is from 100:3 to 100:20, for example 100:3, 100:5, 100:7, 100:9, 100:10, 100:12, 100:15, 100:18 or 100:20, etc.

[0101]

[0102] R tn (n=1-10) are independently hydrogen, deuterium, C1-C18 alkyl or C6-C18 aryl;

[0103] R tn Any one of the groups in (n = 1-10) can form a ring with an aromatic ring or an aromatic heterocycle.

[0104] In some embodiments of the present invention, in the organic light-emitting thin film material composed of a doped material and a host material, the doped material has a molecular structure as shown in Formula I or Formula II, and the host material is composed of any one of the compounds shown in Formula Trz1-A to Trz6-A, any one of the compounds having the structure shown in Formula H-1 to H-10, and any one of the phosphorescent compounds containing metal Pt as shown in Formula Pt-1.

[0105] Preferably, the phosphorescent compound containing metallic Pt is any one of the following compounds:

[0106]

[0107]

[0108] Preferably, the compound having the structure shown in formulas Trz1-A to Trz6-A is any one of the compounds shown in formulas TRZ-1 to TRZ-86.

[0109]

[0110]

[0111]

[0112]

[0113] In some embodiments of the present invention, the thin film luminescent material composed of a host material and a dopant material comprises the following three types of host material: (1) any one of the compounds shown in formulas Trz1-A to Trz6-A and any one of the compounds shown in formulas H1-1 to H1-254 and any one of the phosphorescent compounds containing metal Pt as shown in formula Pt-1; (2) any one of the compounds shown in formulas TRZ-1 to TRZ-86 and any one of the compounds with structures shown in formulas H-1 to H-10 and any one of the phosphorescent compounds containing metal Pt as shown in formulas Ir-1, Ir-2 and Pt-1; (3) any one of the compounds shown in formulas H1-1 to H1-254 and any one of the compounds shown in formulas TRZ-1 to TRZ-86 and any one of the phosphorescent compounds containing metal Ir or Pt as shown in formula Pt-1.

[0114] Preferably, the weight ratio between any one of the compounds shown in TRZ-1 to TRZ-86 and any one of the compounds shown in formulas H1-1 to H1-254 is 1:20 to 20:1, for example 1:20, 1:18, 1:15, 1:10, 1:8, 1:6, 1:5, 1:3, 1:1, 2:1, 5:1, 8:1, 10:1, 12:1, 15:1, 18:1 or 20:1, TRZ The weight ratio of the sum of the weights of any one of the compounds shown in -1 to TRZ-86 and any one of the compounds shown in H1-1 to H1-254 to any one of the phosphorescent compounds containing metal Ir or Pt as shown in Pt-1 is 100:3 to 100:20, for example 100:3, 100:5, 100:8, 100:10, 100:12, 100:15, 100:18 or 100:20.

[0115] Preferably, the weight ratio between the host material and the dopant material in the organic light-emitting thin film is from 99.5:0.5 to 95.0:5.0, for example, 99.5:0.5, 99:1, 96:4, 93:7, 90:10, 85:15, 80:20, 70:30, 60:40, 50:50, 40:60, 30:70, 20:80, 15:85, 10:90, 5:95, etc.

[0116] Preferably, the doping material in the organic light-emitting thin film is any one of the compounds shown in formula BN-1 to BN-272, and the host material is composed of any one of the compounds shown in formula H1-1 to H1-254, any one of the compounds shown in formula TRZ-1 to TRZ-86, and any phosphorescent compound containing metal Pt as shown in formula Pt-1.

[0117] Preferably, the weight ratio between any one of the compounds shown in TRZ-1 to TRZ-86 and any one of the compounds shown in formulas H1-1 to H1-254 is 1:20 to 20:1, and the weight ratio of the sum of the weights of any one of the compounds shown in TRZ-1 to TRZ-86 and any one of the compounds shown in formulas H1-1 to H1-254 to the weight of any phosphorescent compound containing metallic Pt as shown in formula Pt-1 is 100:3 to 100:20.

[0118] Preferably, the weight ratio between the host material and any one of the compound dopants shown in BN-1 to BN-272 in the organic light-emitting film is 99.5:0.5 to 95.0:5.0.

[0119] On the other hand, the present invention provides an organic electroluminescent device comprising an anode and a cathode and an organic thin film layer disposed between the anode and the cathode, the organic thin film layer comprising the organic light-emitting thin film material as described above.

[0120] Preferably, the organic thin film layer includes a light-emitting layer, an optional hole injection layer, an optional hole transport layer, an optional electron transport layer, and an optional electron injection layer, wherein at least one of the light-emitting layer, electron injection layer, electron transport layer, hole transport layer, and hole injection layer comprises the organic light-emitting thin film material as described above.

[0121] In this invention, the organic light-emitting thin film material can be used as a functional material in at least one of the light-emitting layer, electron injection layer, electron transport layer, hole transport layer, and hole injection layer of an organic electroluminescent device.

[0122] In one embodiment of the present invention, the light-emitting layer in the organic electroluminescent device is composed of an organic light-emitting thin film material as described above.

[0123] In one embodiment of the present invention, the organic electroluminescent device further includes a substrate, and an anode layer, an organic light-emitting functional layer, and a cathode layer sequentially formed on the substrate; the organic light-emitting functional layer includes an organic light-emitting thin film material as described above, and may also include any one or a combination of at least two of a hole injection layer, a hole transport layer, an electron blocking layer, a hole blocking layer, an electron transport layer, and an electron injection layer.

[0124] On the other hand, the present invention provides an application of the described organic electroluminescent device in an organic electroluminescent display or an organic electroluminescent lighting source.

[0125] On the other hand, the present invention provides a method for preparing boron nitrogen compounds as shown in Formula I or Formula II as described above, the method comprising the following steps:

[0126] (1) The raw material S undergoes a Suzuki coupling reaction with the raw material S1-Ai or S2-Ai to obtain the intermediate DF-Ri(I);

[0127] (2) Treat intermediate DF-Ri(I) with lithium diisopropylamino (LDA), then mix it with elemental iodine and react to obtain iodinated intermediate I-Ri(I);

[0128] (3) Iodinated intermediate I-Ri(I) reacts with S1-Bi or S2-Bi to obtain intermediate Cz-Ri(I);

[0129] (4) The intermediate Cz-Bi(I) reacts with the raw material S1-Ci or S2-Ci, and then reacts with methanesulfonic acid to obtain the intermediate Spiro-Ci(I);

[0130] (5) The intermediate Spiro-Ci(I) undergoes a lithiation-boration-cyclization reaction to obtain a boron-nitrogen compound with the structure shown in Formula I or Formula II;

[0131] The reaction process is as follows:

[0132]

[0133] Preferably, the molar ratio of raw material S to raw material S1-Ai or S2-Ai in step (1) is 1:1 to 1:10, for example, 1:1, 1:2, 1:3, 1:5, 1:7, 1:8 or 1:10.

[0134] Preferably, the reaction in step (1) is carried out in the presence of a catalyst.

[0135] Preferably, the catalyst is any one or a combination of at least two of tetraphenylphosphine palladium, [1,1'-bis(diphenylphosphine)ferrocene]palladium dichloride, or bis(diphenylphosphine)palladium dichloride.

[0136] Preferably, the reaction in step (1) is carried out in the presence of an alkaline substance selected from potassium carbonate and / or sodium carbonate;

[0137] Preferably, the reaction in step (1) is carried out in a solvent, which is a mixture of tetrahydrofuran and water;

[0138] Preferably, the reaction in step (1) is carried out under reflux and the reaction time is 6 to 48 hours, such as 6 hours, 8 hours, 10 hours, 12 hours, 24 hours, 28 hours, 30 hours, 36 hours, 38 hours, 40 hours, 44 hours or 48 hours.

[0139] Preferably, the molar ratio of lithium diisopropylamino to intermediate DF-Ri(I) in step (2) is 1:1 to 5:1, for example, 1:1, 1.5:1, 2:1, 3:1 or 5:1.

[0140] Preferably, the process of treating intermediate DF-Ri(I) with lithium diisopropylamino in step (2) is as follows: lithium diisopropylamino is added dropwise to the system containing intermediate DF-Ri(I), and the reaction is carried out to obtain intermediate DF-Ri(I) treated with lithium diisopropylamino.

[0141] Preferably, the reaction temperature after adding lithium diisopropylamino is -80 to 0°C, for example -78°C, -40°C, -20°C, etc.; and the reaction time is 0.5 to 12 hours, for example 1 hour, 2 hours, 3 hours, 5 hours, 8 hours, 10 hours, or 12 hours, etc.

[0142] Preferably, the molar ratio of elemental iodine to intermediate DF-Ri(I) in step (2) is 1:1 to 8:1, for example, 1:1, 2:1, 4:1, 8:1, etc.;

[0143] Preferably, the reaction after mixing with iodine in step (2) is carried out in an organic solvent, wherein the organic solvent is any one or a combination of at least two of tetrahydrofuran, 1,4-dioxane, diethyl ether, diphenyl ether, ethylene glycol dimethyl ether or ethylene glycol diethyl ether;

[0144] Preferably, the reaction after mixing with iodine in step (2) is carried out at room temperature for a reaction time of 6 to 48 hours, such as 6 hours, 8 hours, 10 hours, 12 hours, 24 hours, 28 hours, 30 hours, 36 hours, 38 hours, 40 hours, 44 hours or 48 hours.

[0145] Preferably, the molar ratio of the iodinated intermediate I-Ri(I) to S1-Bi or S2-Bi in step (3) is 1:2 to 1:10, for example, 1:2, 1:2.5, 1:3, 1:5, 1:10, etc.

[0146] Preferably, the reaction in step (3) is carried out in the presence of an alkaline substance, which is selected from any one or a combination of at least two of cesium carbonate, potassium carbonate, sodium carbonate, lithium carbonate, potassium phosphate, or potassium acetate.

[0147] Preferably, the reaction in step (3) is carried out in an organic solvent selected from any one or a combination of at least two of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide or hexamethylphosphoric triamine.

[0148] Preferably, the reaction temperature in step (3) is 80 to 180°C, such as 80°C, 100°C, 150°C, 180°C, etc.; the reaction time is 6 to 48 hours, such as 6 hours, 8 hours, 10 hours, 12 hours, 14 hours, 16 hours, 18 hours, 20 hours, 22 hours or 24 hours, etc.

[0149] Preferably, the molar ratio of the intermediate Cz-Bi(I) in step (4) to the raw material S1-Ci or S2-Ci is 1:1 to 1:10, for example, 1:1, 1:1.2, 1:1.5, 1:2, 1:3, 1:5, 1:7, 1:9 or 1:10.

[0150] Preferably, the reaction in step (4) is carried out in the presence of n-butyllithium.

[0151] Preferably, a hexane solution of n-butyllithium is added to a solution containing intermediate Cz-Bi(I) for reaction, and then raw material S1-Ci or S2-Ci is added for further reaction.

[0152] Preferably, the hexane solution of n-butyllithium is added to a solution containing intermediate Cz-Bi(I) at -80 to 0°C (e.g., -78°C, -60°C, -50°C, -40°C, -30°C, -20°C, -10°C, or 0°C).

[0153] Preferably, the reaction temperature for adding the hexane solution of n-butyllithium to the solution containing the intermediate Cz-Bi(I) is -80 to 0°C, for example -78°C, -60°C, -50°C, -40°C, -30°C, -20°C, -10°C, or 0°C; the reaction time is 0.5 to 12 hours, for example 1 hour, 2 hours, 3 hours, 6 hours, 8 hours, 10 hours, 12 hours, etc.

[0154] Preferably, the solution containing the intermediate Cz-Bi(I) is a tetrahydrofuran solution containing the intermediate Cz-Bi(I).

[0155] Preferably, the reaction temperature for adding raw material S1-Ci or S2-Ci is room temperature, and the reaction time is 6 to 48 hours, such as 6 hours, 8 hours, 10 hours, 12 hours, 14 hours, 16 hours, 18 hours, 20 hours, 22 hours or 24 hours.

[0156] Preferably, the molar ratio of intermediate Cz-Bi(I) to methanesulfonic acid in step (4) is 1:1 to 1:20, for example, 1:1, 1:2, 1:3, 1:5, 1:8, 1:10, 1:15, 1:18 or 1:20.

[0157] Preferably, the reaction temperature with methanesulfonic acid in step (4) is room temperature, and the reaction time is 1 to 24 hours, such as 1 hour, 3 hours, 6 hours, 8 hours, 10 hours, 12 hours, 15 hours, 18 hours, 20 hours or 24 hours.

[0158] Preferably, the reaction with methanesulfonic acid in step (4) is carried out in an organic solvent, wherein the organic solvent is any one or a combination of at least two of dichloromethane, trichloromethane, dichloroethane or tetrachloroethane.

[0159] Preferably, the lithiation reagent used in the lithiation stage of the lithiation-boration-cyclization reaction in step (5) is tert-butyllithium.

[0160] Preferably, the molar ratio of the tert-butyllithium to the intermediate Spiro-Ci(I) is 1:1 to 1:3, such as 1:1, 1:1.2, 1:1.3, 1:1.5, 1:2, 1:2.5, 1:2.8 or 1:3.

[0161] Preferably, in the lithiation stage of the lithiation-boration-cyclization reaction in step (5), the lithiation reagent is added to the reaction system containing the intermediate Spiro-Ci(I) at -80 to 0°C (e.g., -78°C, -60°C, -50°C, -40°C, -30°C, -20°C, -10°C, or 0°C).

[0162] Preferably, in step (5), the lithiation stage of the lithiation-boration-cyclization reaction is carried out in an organic solvent, wherein the organic solvent is tert-butylbenzene.

[0163] Preferably, the reaction temperature of the lithiation stage in the lithiation-boration-cyclization reaction in step (5) is 0 to 80°C, such as 0°C, 25°C, 30°C, 40°C, 50°C, 60°C, 70°C or 80°C, and the reaction time is 0.5 to 12 hours, such as 1 hour, 2 hours, 3 hours, 6 hours, 8 hours, 10 hours or 12 hours.

[0164] Preferably, the borizing agent used in the borization stage of the lithiation-boration-cyclization reaction in step (5) is boron tribromide.

[0165] Preferably, the molar ratio of boron tribromide to intermediate Spiro-Ci(I) is 1:1 to 1:5, for example, 1:1, 1:1.2, 1:2, 1:3, 1:4, 1:5, etc.

[0166] Preferably, the boration stage in the lithiation-boration-cyclization reaction in step (5) is carried out at room temperature, and the reaction time is 0.5 to 12 hours, for example, 0.5 hours, 1 hour, 3 hours, 6 hours, 8 hours or 12 hours.

[0167] Preferably, the cyclization stage in the lithiation-boration-cyclization reaction in step (5) is carried out in the presence of N,N-diisopropylethylamine or 1,2,2,6,6-pentamethylpiperidine.

[0168] Preferably, the molar ratio of N,N-diisopropylethylamine or 1,2,2,6,6,-pentamethylpiperidine to intermediate Spiro-Ci(I) is 1:2 to 1:10, for example, 1:2, 1:4, 1:6, 1:8 or 1:10.

[0169] Preferably, the N,N-diisopropylethylamine is added to the reaction system at -80 to 30°C (e.g., -78°C, -60°C, -50°C, -40°C, -30°C, -20°C, -10°C, 0°C, 10°C, 25°C, etc.).

[0170] Preferably, the cyclization stage of the lithiation-boration-cyclization reaction in step (5) is carried out at 80-160°C (e.g., 90°C, 100°C, 120°C, 140°C or 150°C, etc.) for a reaction time of 6-48 hours, such as 6 hours, 10 hours, 12 hours, 15 hours, 18 hours, 20 hours, 24 hours, 30 hours, 36 hours, 40 hours, 44 hours or 48 hours, etc.

[0171] Terminology Explanation

[0172] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0173] As used herein, the terms “containing” or “including (comprise)” can be open-ended, semi-closed, or closed. In other words, the terms also include “consistently made of” or “composed of”.

[0174] Group definition

[0175] In this specification, groups and their substituents may be selected by those skilled in the art to provide stable structural moieties and compounds. When a substituent is described by a conventional chemical formula written from left to right, the substituent also includes chemically equivalent substituents obtained when the structural formula is written from right to left.

[0176] The chapter headings used in this specification are for organizational purposes only and should not be construed as limiting the subject matter. All references or portions thereof cited in this invention, including but not limited to patents, patent applications, articles, books, user manuals, and papers, are incorporated herein by reference in their entirety.

[0177] Unless otherwise specified, all technical and scientific terms used herein have the standard meaning in the field to which the claimed subject matter pertains. Where multiple definitions exist for a term, the definition herein shall prevail.

[0178] It should be understood that the singular forms used in this invention, such as "a," include plural references unless otherwise specified. Furthermore, the term "comprising" is an open-ended limitation, not a closed one; that is, it includes the contents specified in this invention but does not exclude other aspects.

[0179] Unless otherwise stated, this invention employs traditional methods of mass spectrometry and elemental analysis, and the steps and conditions can be referred to conventional operating procedures and conditions in the field.

[0180] Unless otherwise specified, this invention employs standard nomenclature and standard laboratory procedures and techniques of analytical chemistry, organic synthetic chemistry, and optics. In some cases, standard techniques are used for chemical synthesis, chemical analysis, and performance testing of light-emitting devices.

[0181] The compounds of the present invention may contain atomic isotopes in non-natural proportions on one or more atoms constituting the compound. For example, the compounds may be labeled with radioactive isotopes, such as deuterium (₂H). All variations in the isotopic composition of the compounds of the present invention, regardless of radioactivity, are included within the scope of the present invention.

[0182] In this invention, unless otherwise specified, the number of "substitutes" can be one or more; when there are multiples, it means two or more, such as two, three, or four. Furthermore, when there are multiple "substitutes," the "substitutes" can be the same or different. In this invention, unless otherwise specified, the position of the "substitute" can be arbitrary.

[0183] In this invention, as a group or part of other groups (e.g., in halogen-substituted alkyl groups), the term "alkyl" means a saturated aliphatic hydrocarbon group comprising branched and straight chains having a specified number of carbon atoms. For example, C1-C1... 20Alkyl groups include straight-chain or branched alkyl groups having 1 to 20 carbon atoms. As defined in "C1-C6 alkyl," it includes groups having 1, 2, 3, 4, 5, or 6 carbon atoms in a straight-chain or branched structure. For example, in this invention, each of the C1-C6 alkyl groups is independently methyl, ethyl, propyl, butyl, pentyl, or hexyl; wherein, propyl is a C3 alkyl group (including isomers, such as n-propyl or isopropyl); butyl is a C4 alkyl group (including isomers, such as n-butyl, sec-butyl, isobutyl, or tert-butyl); pentyl is a C5 alkyl group (including isomers, such as n-pentyl, 1-methyl-butyl, 1-ethyl-propyl, 2-methyl-1-butyl, 3-methyl-1-butyl, isopentyl, tert-pentyl, or neopentyl); and hexyl is a C6 alkyl group (including isomers, such as n-hexyl or isohexyl).

[0184] As used herein, the term "alkoxy" refers to an alkyl group as defined above, which is connected via an oxygen bond (-O-).

[0185] In this invention, as a group or part of other groups, the term "Cn-m aryl" refers to a monocyclic or polycyclic aromatic group (with only carbon atoms as ring atoms) having n to m ring carbon atoms, possessing at least one carbon ring with a conjugated π-electron system. Examples of the aforementioned aryl unit include phenyl, naphthyl, indene, azulel, fluorenyl, phenanthryl, or anthraceneyl. In one embodiment, the aryl group is preferably a C6-14 aryl group, such as phenyl and naphthyl, more preferably phenyl.

[0186] In this invention, as a group or part of other groups, the term "nm-aryl" refers to an aromatic group whose ring atoms comprise one or more (e.g., 1, 2, 3, and 4) heteroatoms selected from nitrogen, oxygen, and sulfur, having n to m ring atoms. The heteroaryl group is a monocyclic, bicyclic, tricyclic, or tetracyclic system, wherein at least one ring is an aromatic ring. Heteroaryl groups within this definition include, but are not limited to: acridinel, carbazolyl, cyclophosphinyl, quinoxalinyl, pyrazolyl, indolyl, benzotriazolyl, furanyl, thiophene, benzothiophene, benzofuranyl, quinolinyl, isoquinolinyl, oxazolyl, isoxazolyl, pyrazinyl, pyridinyl, pyrimidinel, pyrroleyl, tetrahydroquinoline, imidazolyl, triazolyl, tetrazolyl, thiazolyl, isothiazolyl, furazolyl, thiadiazolyl, etc. Oxadiazole, pyridinyl, pyrazinyl, pyridazinyl, pyrimidinyl, triazinyl, purine, pteridinyl, naphridinyl, quinazolinyl, phthalazinyl, imidazopyridinyl, imidazothiazolyl, imidazooxazinyl, benzothiazolyl, benzooxazinyl, benzoimidazolyl, isoindolyl, indazole, pyrrolopyridinyl, thienopyridinyl, furanolopyridinyl, benzothiadiazole, benzooxadiazole, pyrrolopyrimidinyl, thienofuranyl. In one embodiment, as preferred examples of "5- to 18-membered heteroaryl groups", furanyl, thienoyl, pyrrololyl, imidazolyl, thiazolyl, pyrazolyl, oxazolyl, isoxazolyl, isothiazolyl, pyridinyl, pyrimidinyl, and carbazoleyl are listed, more preferably carbazoleyl.

[0187] As used herein, the term Cn-Cm cycloalkyl refers to a monocyclic or polycyclic alkyl group having n to m carbon atoms, such as 3-C10 cycloalkyl and C3-C6 cycloalkyl. Examples include adamantyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and dicycloheptyl. In one embodiment, the C3-C10 cycloalkyl group is preferably adamantyl or cyclohexyl.

[0188] In this invention, the defined carbon number range of the group refers to any integer number of carbon atoms included within the defined range, such as C1 to C2. 20 This refers to the fact that the number of carbon atoms in the stated group can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20, C3-C. 10 This means that the number of carbon atoms in the group can be 3, 4, 5, 6, 7, 8, 9 or 10, and the range of carbon atoms for other groups can be deduced similarly.

[0189] Without violating common sense in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0190] The reagents and raw materials used in this invention are all commercially available.

[0191] Compared with the prior art, the present invention has the following beneficial effects:

[0192] This invention obtains a thin-film luminescent material with narrow-spectrum luminescence characteristics through the optimized combination of doping materials and host materials. It can be used to prepare the luminescent layer of organic electroluminescent devices. The organic electroluminescent devices prepared in this way achieve narrow-spectrum TADF emission with a half-width of less than 40 nm, and make the highest external quantum efficiency of electroluminescence of the device reach more than 30%, and have a high device lifetime. Attached Figure Description

[0193] Figure 1 This is a schematic diagram of the structure of the organic electroluminescent device of the present invention, wherein 1 is the ITO anode, 2 is the first hole transport layer, 3 is the second hole transport layer, 4 is the light-emitting layer, 5 is the second electron transport layer, 6 is the first electron transport layer, 7 is the electron injection layer, and 8 is the metal cathode.

[0194] Figure 2 This is the photoluminescence spectrum of compound BN-1.

[0195] Figure 3 This is the photoluminescence spectrum of compound BN-37.

[0196] Figure 4 This is the photoluminescence spectrum of compound BN-41.

[0197] Figure 5 This is the electroluminescence spectrum of compound BN-1.

[0198] Figure 6 This is the electroluminescence spectrum of compound BN-37.

[0199] Figure 7 This is the electroluminescence spectrum of compound BN-41.

[0200] Figure 8 The results are obtained by thin-layer chromatography (TLC) of the product reaction solution generated in the first step of the preparation route of this invention and the preparation route of the prior art. Detailed Implementation

[0201] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0202] The synthetic route and specific operations used to synthesize the compound shown in Formula I are as follows:

[0203]

[0204] First, using arylboronic acid raw materials S1-Ai (i = 1-12), the substituted group R modifies the halogenated aromatic ring core through a Suzuki coupling reaction, yielding intermediate DF-Ri(I) (i = 1-12). Subsequently, the intermediate DF-Ri(I), treated with lithium diisopropylamino, is mixed with elemental iodine and stirred thoroughly to obtain the iodinated intermediate I-Ri(I). Then, a simple aryl nucleophilic substitution reaction introduces the carbazole derivative S1-Bi, yielding intermediate Cz-Ri(I). Further, the hydroxyl intermediate is obtained by mixing the n-butyllithium-treated intermediate Cz-Ri(I) with the 9-fluorenone derivative S1-Ci and stirring thoroughly. This hydroxyl intermediate undergoes intramolecular dehydration cyclization under acidic conditions without further purification, generating Spiro-Ci(I). A one-pot lithiation-boration-cyclization tandem reaction is then used to obtain the target product BN-n(I).

[0205] In the first step, 150.0 mmol of arylboronic acid compound S1-Ai, 160.0 mmol of 1-bromo-3-chloro-2,4-difluorobenzene, and 300.0 mmol of potassium carbonate were added to 800 mL of a tetrahydrofuran / water mixture (volume ratio 4:1). The mixture was bubbled under nitrogen for 10 minutes, and 2.0 mmol of tetratriphenylphosphine was added under high flow rate nitrogen. The mixture was heated to reflux and stirred for 12 hours. After the reaction system cooled to room temperature, the reaction mixture was extracted with dichloromethane and water, and the organic phase was dried under vacuum by heating. The purified product was then purified by column chromatography and recrystallization to obtain intermediate DF-Ri(I).

[0206] In the second step, under a nitrogen atmosphere, an ultra-dry tetrahydrofuran mixture containing DF-Ri(I) (100.0 mmol) was thoroughly cooled to -40°C, and lithium diisopropylamino (120.0 mmol) was slowly added dropwise. After stirring the reaction system at -40°C for 2 hours, an ultra-dry tetrahydrofuran solution containing iodine (150.0 mmol) was slowly added dropwise, and the system was stirred at room temperature for 12 hours. After the reaction was complete, the reaction mixture was extracted with dichloromethane and water, the organic phase was dried under vacuum, and then purified by column chromatography and recrystallization to obtain intermediate I-Ri(I) (i = 1-12).

[0207] In the third step, under a nitrogen atmosphere, 100.0 mmol of raw materials I-Ri(I), S1-Bi (220.0 mmol) and cesium carbonate (300.0 mmol) were added to N,N-dimethylformamide (800 mL), stirred at 150 °C for 24 hours, then cooled to room temperature, and the reaction mixture was extracted with dichloromethane and water. The organic phase was dried under vacuum by heating, and then purified by column chromatography to obtain the intermediate Cz-Bi(I).

[0208] In the fourth step, under a nitrogen atmosphere, a hexane solution of 60.0 mmol of n-butyllithium was slowly added to a 200 mL tetrahydrofuran solution (-30 °C) containing 50.0 mmol of intermediate Cz-Bi(I), and the reaction was carried out at this temperature for 2 hours. Subsequently, a tetrahydrofuran solution of the starting material S1-Ci was slowly added, and the system was stirred at room temperature for 24 hours. The reaction mixture was extracted with dichloromethane and an aqueous solution of ammonium chloride, and the organic phase was evaporated to dryness under vacuum to obtain the hydroxyl intermediate. This intermediate was then dissolved in dichloromethane, and 200.0 mmol of methanesulfonic acid was slowly added with stirring at room temperature, and the reaction was continued at room temperature for 6 hours. The reaction mixture was then extracted with dichloromethane and an aqueous solution, and the organic phase was evaporated to dryness under vacuum to obtain the intermediate Spiro-Ci(I).

[0209] In step 5, a hexane solution of 60.0 mmol tert-butyllithium was slowly added to a 100 mL tert-butylbenzene solution containing 30.0 mmol intermediate Spiro-Ci(I) (at -30°C). The mixture was slowly heated to 60°C and stirred for 2 hours, then cooled to -30°C, and 60.0 mmol boron tribromide was added. The reaction mixture was stirred at room temperature for 1 hour. Next, N,N-diisopropylethylamine (120.0 mmol) was added at 0°C, and the reaction mixture was heated to 150°C and stirred for 12 hours, then cooled to room temperature. The reaction mixture was concentrated under vacuum and purified by column chromatography using a mixture of dichloromethane and petroleum ether as eluent to obtain the final product BN-n.

[0210] The specific raw material S1-A used includes the following molecules:

[0211]

[0212] The specific raw material S1-B used includes the following molecules:

[0213]

[0214] The specific raw material S1-C used includes the following molecules:

[0215]

[0216] The synthetic route and specific details of the experiment are illustrated using the example of the synthesis of compound BN-1:

[0217]

[0218] In the first step, under a nitrogen atmosphere, 43.1 g of starting material S1-A5 (150.0 mmol), 36.1 g of starting material 1-bromo-3-chloro-2,4-difluorobenzene (160.0 mmol), and 41.5 g of potassium carbonate (300.0 mmol) were added to 800 mL of a tetrahydrofuran / water mixture (4:1, v / v). The mixture was bubbled with nitrogen for 10 minutes, and 2.0 mmol of tetratriphenylphosphine was added under high flow rate nitrogen. The mixture was heated to reflux and stirred for 12 hours. After the reaction system cooled to room temperature, the reaction mixture was extracted with dichloromethane and water, and the organic phase was dried under vacuum by heating. The purified product was then purified by column chromatography and recrystallization to give a white solid DF-R5(I) in 86.4% yield.

[0219] In the second step, under a nitrogen atmosphere, an ultra-dry tetrahydrofuran mixture containing 39.0 g of the starting material DF-R5(I) (100.0 mmol) was thoroughly cooled to -40 °C, and 60 mL of diisopropylaminolithium (120.0 mmol, 2.0 M) was slowly added dropwise. After stirring the reaction system at -40 °C for 2 hours, an ultra-dry tetrahydrofuran solution containing 38.1 g of iodine (150.0 mmol) was slowly added dropwise, and the system was stirred at room temperature for 12 hours. After the reaction was complete, the reaction mixture was extracted with dichloromethane and water, the organic phase was dried under vacuum, and then purified by column chromatography and recrystallization to obtain a white intermediate I-R5(I) in 80.4% yield.

[0220] In the third step, under a nitrogen atmosphere, 51.6 g of raw material I-R5(I) (100.0 mmol), 61.5 g of raw material S1-B1 (220.0 mmol), and 104.4 g of cesium carbonate (300.0 mmol) were added to 800 mL of DMF. The mixture was stirred at reflux temperature for 12 hours, then cooled to room temperature. The reaction mixture was extracted with dichloromethane and water. The organic phase was dried under vacuum and then purified by column chromatography to obtain intermediate Cz-B1(I) (white solid, yield: 88%).

[0221] In the fourth step, under a nitrogen atmosphere, a hexane solution of 60 mmol of n-butyllithium was slowly added to a 400 mL tetrahydrofuran solution (-30 °C) containing 51.7 g of intermediate Cz-B1(I) (50 mmol), and the reaction was carried out at this temperature for 2 hours. Subsequently, a tetrahydrofuran solution of 10.8 g of S1-C1 (9-fluorenone, 60 mmol) was slowly added, and the system was stirred at room temperature for 24 hours. The reaction mixture was extracted with dichloromethane and an aqueous solution of ammonium chloride, and the organic phase was evaporated to dryness under vacuum to obtain the hydroxyl intermediate. This intermediate was then dissolved in dichloromethane, and 200.0 mmol of methanesulfonic acid was slowly added with stirring at room temperature, and the reaction was continued at room temperature for 6 hours. The reaction mixture was then extracted with dichloromethane and an aqueous solution, and the organic phase was evaporated to dryness under vacuum to obtain intermediate Spiro-C1(I) (white solid, yield: 54%).

[0222] In step 5, a hexane solution of 60 mmol of tert-butyllithium was slowly added to a 200 mL tert-butylbenzene solution (-30°C) containing 32.1 g of intermediate Spiro-C1(I) (30.0 mmol). The mixture was slowly heated to room temperature and stirred for 2 hours, then cooled to -30°C, and 15.0 g of boron tribromide (60.0 mmol) was added. The reaction mixture was stirred at room temperature for 1 hour. Then, 15.5 g of DIEA (120.0 mmol) was added at 0°C, and the reaction mixture was heated to 150°C and stirred for 12 hours, then cooled to room temperature. The reaction mixture was concentrated under vacuum and purified by column chromatography using a mixture of dichloromethane and petroleum ether as eluent to give the yellow target product BN-1 in 33.5% yield.

[0223] The synthetic route and specific operations used to synthesize the compound shown in Formula II are as follows:

[0224]

[0225] First, using the arylboronic acid raw material S2-Ai, the halogenated aromatic ring core was modified by the substituent group R via a Suzuki coupling reaction, yielding intermediate DF-Ri(II) (i = 1-12). Subsequently, the intermediate DF-Ri(II) (i = 1-12) treated with lithium diisopropylaminoamine was mixed with elemental iodine and stirred thoroughly to obtain the iodinated intermediate I-Ri(II). Then, a simple aryl nucleophilic substitution reaction was performed to introduce the carbazole derivative S2-Bi, yielding intermediate Cz-Ri(II). Further, the hydroxyl intermediate was obtained by mixing the intermediate Cz-Ri(II) treated with n-butyllithium with the 9-fluorenone derivative S2-Ci and stirring thoroughly. This hydroxyl intermediate, without further purification, underwent intramolecular dehydration cyclization under acidic conditions to generate Spiro-Ci(II). A one-pot lithium...

[0226] The target product BN-n(II) was obtained by a series of chemical-boration-cyclization reactions.

[0227] In the first step, 150.0 mmol of arylboronic acid compound S2-Ai, 160.0 mmol of 1-bromo-3-chloro-2,4-difluorobenzene, and 300.0 mmol of potassium carbonate were added to 800 mL of a tetrahydrofuran / water mixture (volume ratio 4:1). The mixture was bubbled under nitrogen for 10 minutes, and 2.0 mmol of tetratriphenylphosphine was added under high flow rate nitrogen. The mixture was heated to reflux and stirred for 12 hours. After the reaction system cooled to room temperature, the reaction mixture was extracted with dichloromethane and water, and the organic phase was dried under vacuum by heating. The purified product was then purified by column chromatography and recrystallization to obtain intermediate DF-Ri(II).

[0228] In the second step, under a nitrogen atmosphere, an ultra-dry tetrahydrofuran mixture containing DF-Ri(II) (100.0 mmol) was thoroughly cooled to -40°C, and lithium diisopropylamino (120.0 mmol) was slowly added dropwise. After stirring the reaction system at -40°C for 2 hours, an ultra-dry tetrahydrofuran solution containing iodine (150.0 mmol) was slowly added dropwise, and the system was stirred at room temperature for 12 hours. After the reaction was complete, the reaction mixture was extracted with dichloromethane and water, the organic phase was dried under vacuum, and then purified by column chromatography and recrystallization to obtain intermediate I-Ri(II).

[0229] Thirdly, under a nitrogen atmosphere, 100.0 mmol of raw materials I-Ri(II), S2-Bi (220.0 mmol) and cesium carbonate (300.0 mmol) were added to N,N-dimethylformamide (800 mL), stirred at 150 °C for 24 hours, then cooled to room temperature, and the reaction mixture was extracted with dichloromethane and water. The organic phase was dried under vacuum by heating, and then purified by column chromatography to obtain intermediate Cz-Bi(II).

[0230] In the fourth step, under a nitrogen atmosphere, a hexane solution of 60.0 mmol of n-butyllithium was slowly added to a 200 mL tetrahydrofuran solution (-30 °C) containing 50.0 mmol of intermediate Cz-Bi(II) (i = 1-8), and the reaction was carried out at this temperature for 2 hours. Subsequently, a tetrahydrofuran solution of the starting material S2-Ci was slowly added, and the system was stirred at room temperature for 24 hours. The reaction mixture was extracted with dichloromethane and an aqueous solution of ammonium chloride, and the organic phase was evaporated to dryness under vacuum to obtain the hydroxyl intermediate. This intermediate was then dissolved in dichloromethane, and 200.0 mmol of methanesulfonic acid was slowly added with stirring at room temperature, and the reaction was continued at room temperature for 6 hours. The reaction mixture was then extracted with dichloromethane and an aqueous solution, and the organic phase was evaporated to dryness under vacuum to obtain the intermediate Spiro-Ci(II).

[0231] In step 5, a hexane solution of 60.0 mmol tert-butyllithium was slowly added to a 100 mL tert-butylbenzene solution containing 30.0 mmol intermediate Spiro-Ci(II) (at -30°C). The mixture was slowly heated to 60°C and stirred for 2 hours, then cooled to -30°C, and 60.0 mmol boron tribromide was added. The reaction mixture was stirred at room temperature for 1 hour. Next, N,N-diisopropylethylamine (120.0 mmol) was added at 0°C, and the reaction mixture was then heated to 150°C and stirred for 12 hours, before cooling to room temperature. The reaction mixture was concentrated under vacuum and purified by column chromatography using a mixture of dichloromethane and petroleum ether as eluent to obtain the final product BN-n.

[0232] The specific raw material S2-A used includes the following molecules:

[0233]

[0234] The specific raw material S2-B used includes the following molecules:

[0235]

[0236] The specific raw material S2-C used includes the following molecules:

[0237]

[0238] The synthetic route and specific details of the experiment are illustrated using the synthesis example of compound BN-125:

[0239] In the first step, under a nitrogen atmosphere, 43.1 g of starting material S2-A5 (150.0 mmol), 36.1 g of starting material 1-bromo-3-chloro-2,4-difluorobenzene (160.0 mmol), and 41.5 g of potassium carbonate (300.0 mmol) were added to 800 mL of a tetrahydrofuran / water mixture (4:1, v / v). The mixture was bubbled with nitrogen for 10 minutes, and 2.0 mmol of tetratriphenylphosphine was added under high flow rate nitrogen. The mixture was heated to reflux and stirred for 12 hours. After the reaction system cooled to room temperature, the reaction mixture was extracted with dichloromethane and water, and the organic phase was dried under vacuum by heating. The purified product was then purified by column chromatography and recrystallization to give a white solid DF-R5(II) in 86.4% yield.

[0240] In the second step, under a nitrogen atmosphere, an ultra-dry tetrahydrofuran mixture containing 39.0 g of the starting material DF-R5(II) (100.0 mmol) was thoroughly cooled to -40 °C, and 60 mL of diisopropylaminolithium (120.0 mmol, 2.0 M) was slowly added dropwise. After stirring the reaction system at -40 °C for 2 hours, an ultra-dry tetrahydrofuran solution containing 38.1 g of iodine (150.0 mmol) was slowly added dropwise, and the system was stirred at room temperature for 12 hours. After the reaction was complete, the reaction mixture was extracted with dichloromethane and water, the organic phase was dried under vacuum, and then purified by column chromatography and recrystallization to obtain a white intermediate I-R5(II) in 80.4% yield.

[0241] In the third step, under a nitrogen atmosphere, 51.6 g of raw material I-R5(II) (100.0 mmol), 61.5 g of raw material S2-B1 (220.0 mmol), and 104.4 g of cesium carbonate (300.0 mmol) were added to 800 mL of DMF. The mixture was stirred at reflux temperature for 12 hours, then cooled to room temperature. The reaction mixture was extracted with dichloromethane and water. The organic phase was dried under vacuum by heating, and then purified by column chromatography to obtain intermediate Cz-B1(II) (white solid, yield: 88%).

[0242] In the fourth step, under a nitrogen atmosphere, a hexane solution of 60 mmol of n-butyllithium was slowly added to a 400 mL tetrahydrofuran solution (-30 °C) containing 51.7 g of intermediate Cz-B1(II) (50 mmol), and the reaction was carried out at this temperature for 2 hours. Subsequently, a tetrahydrofuran solution of 10.9 g of S2-C1 (benzophenone, 60 mmol) was slowly added, and the system was stirred at room temperature for 24 hours. The reaction mixture was extracted with dichloromethane and an aqueous solution of ammonium chloride, and the organic phase was evaporated to dryness under vacuum to obtain the hydroxyl intermediate. This intermediate was then dissolved in dichloromethane, and 200.0 mmol of methanesulfonic acid was slowly added with stirring at room temperature, and the reaction was continued at room temperature for 6 hours. The reaction mixture was then extracted with dichloromethane and an aqueous solution, and the organic phase was evaporated to dryness under vacuum to obtain intermediate Spiro-C1(II) (white solid, yield: 48%).

[0243] In step 5, a hexane solution of 60 mmol of tert-butyllithium was slowly added to a 200 mL tert-butylbenzene solution (-30°C) containing 32.1 g of intermediate Spiro-C1(II) (30.0 mmol). The mixture was slowly heated to room temperature and stirred for 2 hours, then cooled to -30°C, and 15.0 g of boron tribromide (60.0 mmol) was added. The reaction mixture was stirred at room temperature for 1 hour. Then, 15.5 g of DIEA (120.0 mmol) was added at 0°C, and the reaction mixture was heated to 150°C and stirred for 12 hours, then cooled to room temperature. The reaction mixture was concentrated under vacuum and purified by column chromatography using a mixture of dichloromethane and petroleum ether as eluent to give the yellow target product BN-125 in 35.4% yield.

[0244]

[0245] The data from the synthesis examples are summarized in Table H1.

[0246] Table H1. Summary of data from the synthesis examples

[0247]

[0248]

[0249] Figure 2 The emission spectrum of compound BN-1 in toluene solution is shown (emission peak position: 519 nm; full width at half maximum: 32 nm).

[0250] Figure 3 Emission spectrum of compound BN-37 in toluene solution (emission peak position: 523 nm; full width at half maximum: 33 nm).

[0251] Figure 4 Emission spectrum of compound BN-41 in toluene solution (emission peak position: 521 nm; full width at half maximum: 32 nm). Comparative synthesis example:

[0252] The following synthetic route has also been verified in the synthesis of compounds such as BN-1:

[0253] Comparison process 1:

[0254]

[0255] Comparison Process 2:

[0256]

[0257] Both comparative processes 1 and 2 share a common problem: in the first step, using 1,5-dibromo-2,4-difluorobenzene as the initial reactant, a large number of unavoidable byproducts are generated during the Suzuki coupling reaction to introduce aromatic substituents into the central benzene ring. These byproducts are difficult to separate and purify, affecting the purity of all subsequent reaction products. For example... Figure 8 As shown in a), the aromatic-substituted target intermediate produced in this step has a very similar polarity to the starting material 1,5-dibromo-2,4-difluorobenzene. Furthermore, the starting material 1,5-dibromo-2,4-difluorobenzene is a liquid product (which needs to be added in excess to the reaction system to obtain the monophenylcarbazole-substituted target intermediate). Ultimately, this results in the inability to separate the target intermediate from the starting material (1,5-dibromo-2,4-difluorobenzene) using column chromatography. In addition, the reaction is accompanied by the formation of a byproduct impurity, which affects the purity and yield of the product.

[0258] Figure 8 b) shows the thin-layer chromatography (TLC) result of step (1) in the technical route of the present invention, in which an aromatic substituent group is introduced into the central benzene ring (the product is DF-R5(I)), wherein the mobile phase is petroleum ether.

[0259] Furthermore, the third step of the reaction in Comparative Process 2 involves the use of BF3 diethyl ether. Boron trifluoride-diethyl ether is highly irritating and toxic, and readily hydrolyzes in water, producing toxic and corrosive fumes that pollute the environment. Additionally, its production and disposal processes also generate harmful substances, causing long-term environmental impacts.

[0260] Compared with comparative processes 1-2, the synthesis process route provided by the present invention has the following advantages:

[0261] (1) When 1-bromo-3-chloro-2,4-difluorobenzene is used as the reverse initiator, the bromine atom has high reactivity in the Suzuki coupling reaction and there is a significant difference in reactivity between it and the chlorine atom. Therefore, when a key aromatic substituent group is introduced into the central benzene ring using this reaction, the yield can reach 80-90%, and the system has a single composition and is easy to purify.

[0262] (2) By treating the hydrogen atom located adjacent to the fluorine atom with a sterically hindered strong base (N,N-diisopropylaminolithium), a functional group (iodine atom) can be efficiently introduced at a specific target site and used for the subsequent introduction of a spirofluorene group. The reaction yield can reach over 80%, and no column chromatography purification is required in large-scale production.

[0263] (3) When introducing the spirofluorene group, a carbanion intermediate is obtained through iodine-lithium exchange, and the better leaving property of the iodine atom makes the process more efficient. Subsequently, to avoid the use of highly toxic boron trifluoride-diethyl ether, the synthetic route we provide is achieved in more than 90% yield at room temperature by protonating the hydroxyl group with methanesulfonic acid and catalyzing an intramolecular dehydration cyclization reaction.

[0264] Examples of electroluminescent devices

[0265] The following are some representative examples of electroluminescent devices. The molecular structures of some materials involved in the device examples and comparative examples are as follows:

[0266]

[0267]

[0268] The following are examples of electroluminescent devices fabricated using the materials of the present invention, and the specific device fabrication process is as follows:

[0269] Fabrication process of organic electroluminescent devices:

[0270] The results of the device are as follows Figure 1 As shown, 1 is the ITO anode, 2 is the first hole transport layer, 3 is the second hole transport layer, 4 is the light-emitting layer, 5 is the second electron transport layer, 6 is the first electron transport layer, 7 is the electron injection layer, and 8 is the metal cathode.

[0271] The preparation process is as follows:

[0272] (1) Substrate treatment: Transparent ITO glass was used as the substrate material for device fabrication. It was first ultrasonically treated with 5% ITO cleaning solution for 30 minutes, then sequentially ultrasonically washed with distilled water (twice), acetone (twice), and isopropanol (twice). Finally, the ITO glass was stored in isopropanol. Before each use, the surface of the ITO glass was carefully wiped with acetone and isopropanol cotton balls, rinsed with isopropanol, dried, and then plasma-treated for 5 minutes before use. Device fabrication was completed using a combination of spin coating and vacuum evaporation processes.

[0273] (2) Preparation of hole injection layer and hole transport layer: The hole transport layer was prepared by evaporation process. When the vacuum degree of the vacuum evaporation system reached 5×10 -4 Vacuum deposition begins when the pressure is below a certain level. The deposition rate is determined using a Sines film thickness gauge. Organic hole transport layers are sequentially deposited on the ITO electrode surface using a vacuum evaporation process. The deposition rate of the hole transport material is [missing information].

[0274] (3) Preparation of the light-emitting layer: The light-emitting layer is prepared by evaporation deposition process. When the vacuum degree of the vacuum evaporation deposition system reaches 5×10 -4 Vacuum deposition begins when the pressure is below a certain level (Pa). The deposition rate is determined using a SAINS film thickness gauge. The luminescent layer is sequentially deposited on the hole transport layer using a vacuum evaporation process. The deposition rate of the luminescent layer material is [missing information].

[0275] (4) Fabrication of electron transport layer, electron injection layer and metal electrode: The electron transport layer, electron injection layer and metal electrode are fabricated using a vapor deposition process. When the vacuum degree of the vacuum vapor deposition system reaches 5×10 -4 Vapor deposition begins when the pressure is below a certain level (Pa). The deposition rate is measured using a SAINS film thickness gauge. An organic electron transport layer, a LiF electron injection layer, and a metal Al electrode are sequentially deposited on the light-emitting layer using a vacuum evaporation process (see the following effect example for specific device structure). The deposition rate of the organic material is [missing information - likely a specific value]. The deposition rate of LiF is The deposition rate of Al is Device Example 1-n (n=32)

[0276] Organic electroluminescent devices (structures as shown in Device Examples 1-n (n = 1-32)) Figure 1 In the example shown, HIM-doped HTL-1 is used as the first hole transport layer, HTL-2 is used as the second hole transport layer, H1-227+2CN-37 is used as the host material in the light-emitting layer, BN-m (m represents the last digit of the light-emitting material code used in the device embodiment) is used as the doped light-emitting material (doping concentration is 1wt%), TRZ-83 is used as the second electron transport layer, TRZ-85 is used as the first electron transport layer, LiF is used as the electron injection layer, and Al is used as the metal cathode. The structure of the organic electroluminescent device in the effect embodiment is [ITO / 15wt%HIM+85wt%HTL-1(100nm) / HTL-2(10nm) / 70wt%H1-227+29wt%2CN-37+1wt%BN-m(30nm) / TRZ-83(10nm) / TRZ-85(30nm)LiF(1nm) / Al(100nm)].

[0277] Performance data for the device embodiments are shown in Table 1. In Table 1, the device lifetime (T50, hours) refers to the device's initial brightness of 1000 cd / m². 2 When the brightness of the device drops to 50% of its initial brightness (i.e., the device brightness drops to 500 cd / m²), 2 The time required (in hours).

[0278] Comparative device embodiments D1-n (n=1-9)

[0279] Organic electroluminescent devices (structures as shown in the comparative device embodiments D1-n (n=1-9)) Figure 1In the example shown, HIM-doped HTL-1 is used as the first hole transport layer, HTL-2 is used as the second hole transport layer, H1-227+2CN-37 is used as the host material in the light-emitting layer, Rm (m represents the last digit of the light-emitting material code used in the device embodiment) is used as the doped light-emitting material (doping concentration is 1wt%), TRZ-83 is used as the second electron transport layer, TRZ-85 is used as the first electron transport layer, LiF is used as the electron injection layer, and Al is used as the metal cathode. The structure of the organic electroluminescent device in the effect embodiment is [ITO / 15wt%HIM+85wt%HTL-1(100nm) / HTL-2(10nm) / 70wt%H1-227+29wt%2CN-37+1wt%Rm(30nm) / TRZ-83(10nm) / TRZ-85(30nm)LiF(1nm) / Al(100nm)].

[0280] Performance data for the device embodiment are shown in Table D1. In Table D1, the device lifetime (T50, hours) refers to the device's initial luminance of 1000 cd / m². 2 When the brightness of the device drops to 50% of its initial brightness (i.e., the device brightness drops to 500 cd / m²), 2 The time required (in hours).

[0281] Figure 5 Electroluminescence spectrum of compound BN-1 (emission peak position: 524 nm; full width at half maximum: 37 nm).

[0282] Figure 6 Electroluminescence spectrum of compound BN-37 (emission peak position: 528 nm; full width at half maximum: 37 nm).

[0283] Figure 7 Electroluminescence spectrum of compound BN-41 (emission peak position: 525 nm; full width at half maximum: 36 nm).

[0284] Table 1

[0285]

[0286] Table D1

[0287]

[0288]

[0289] Device Example 2-n (n = 1-32)

[0290] Organic electroluminescent devices (structure as shown in Device Examples 2-n (n = 1-32)) Figure 1In the diagram, HIM-doped HTL-1 is used as the first hole transport layer, HTL-2 is used as the second hole transport layer, H1-1+TRZ-83+PtPy is used as the host material in the light-emitting layer, BN-m (m represents the last digit of the light-emitting material code used in the device embodiment) is used as the doped light-emitting material (doping concentration is 1wt%), TRZ-83 is used as the second electron transport layer, TRZ-85 is used as the first electron transport layer, LiF is used as the electron injection layer, and Al is used as the metal cathode. The structure of the organic electroluminescent device in the example is [ITO / 15wt%HIM+85wt%HTL-1(100nm) / HTL-2(10nm) / 60wt%H1-1+30wt%TRZ-83+9wt%PtPy+1wt%BN-m(30nm) / TRZ-83(10nm) / TRZ-85(30nm)LiF(1nm) / Al(100nm)].

[0291] Performance data for the device embodiments are shown in Table 2. In Table 2, the device lifetime (T50, hours) refers to the device's initial brightness of 1000 cd / m². 2 When the brightness of the device drops to 50% of its initial brightness (i.e., the brightness of the device drops to 500 cd / m²), 2 The time required (in hours).

[0292] Comparative device embodiment D2-n (n=1-9)

[0293] The organic electroluminescent devices (structure as shown in the comparative device examples D2-n (n=1-9)) Figure 1 In the diagram, HIM-doped HTL-1 is used as the first hole transport layer, HTL-2 is used as the second hole transport layer, H1-1+TRZ-83+PtPy is used as the host material in the light-emitting layer, Rm (m represents the last digit of the light-emitting material code used in the device embodiment) is used as the doped light-emitting material (doping concentration is 1wt%), TRZ-83 is used as the second electron transport layer, TRZ-85 is used as the first electron transport layer, LiF is used as the electron injection layer, and Al is used as the metal cathode. The structure of the organic electroluminescent device in the example is [ITO / 15wt%HIM+85wt%HTL-1(100nm) / HTL-2(10nm) / 60wt%H1-1+30wt%TRZ-83+9wt%PtPy+1wt%Rm(30nm) / TRZ-83(10nm) / TRZ-85(30nm)LiF(1nm) / Al(100nm)].

[0294] Performance data for the device embodiment are shown in Table D2. In Table D2, the device lifetime (T50, hours) refers to the device's initial luminance of 1000 cd / m².2 When the brightness of the device drops to 50% of its initial brightness (i.e., the brightness of the device drops to 500 cd / m²), 2 The time required (in hours).

[0295] Table 2

[0296]

[0297]

[0298] Table D2

[0299]

[0300] The organic electroluminescent device prepared by this invention achieves narrow-spectrum TADF emission, with the electroluminescence spectrum located in the green-red light region and a half-width of less than 40 nm. Furthermore, the device achieves a maximum external quantum efficiency of over 30% and a high lifetime.

[0301] The applicant declares that the present invention is illustrated by the above embodiments, but the present invention is not limited to the above process steps, that is, it does not mean that the present invention must rely on the above process steps to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials used in 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. An organic light-emitting thin film material, characterized in that, The organic light-emitting thin film material includes a dopant material and a host material, wherein the dopant material is a boron-nitrogen compound having the following formula I or formula II: R is selected from the groups shown in formula R-1, R-2, R-3, or R-4: R CZ Selected from 5- to 18-membered heteroaryl groups, with one or more R groups 0 Substituted 5- to 18-membered heteroaryl, diphenylamino, or substituted with one or more R 0 Substituted diphenylamine group; R 01 and R 02 Independently selected from H, deuterium, C1-C20 alkyl, C1-C20 alkoxy, C3-C10 cycloalkyl, C6-C18 aryl, and dominated by one or more R 0 Substituted C6-C18 aryl, 5- to 18-heteroaryl, and substituted with one or more R 0 Substituted 5- to 18-membered heteroaryl, diphenylamino, or substituted with one or more R 0 Substituted diphenylamine group; R 0 Each time it appears, it is independently deuterium, fluorine, C1-C12 alkyl, C1-C12 alkoxy, C3-C12 cycloalkyl, C6-C14 aryl, 5- to 18-membered heteroaryl or diphenylamino; R 1 R 2 R 3 R 4 R 5 R 6 R 7 and R 8 Independently selected from H, deuterium, C1-C20 alkyl, C1-C20 alkoxy, C3-C10 cycloalkyl, C6-C18 aryl, and dominated by one or more R a Substituted C6-C18 aryl, 5- to 18-heteroaryl, and substituted with one or more R a Substituted 5- to 18-membered heteroaryl, diphenylamino, or substituted with one or more R a The substituted diphenylamine group, and R 1 and R 8 R 2 and R 7 R 3 and R 6 Or R 4 and R 5 In at least one of the four pairs of substituent groups, the two substituents in one pair are different; R a Each occurrence is independently of deuterium, fluorine, CN, C1-C12 alkyl, C1-C12 alkoxy, C3-C12 cycloalkyl, C6-C14 aryl, and is accompanied by one or more R. b Substituted C6-C14 aryl, 5- to 18-membered heteroaryl, and substituted with one or more R b Substituted 5- to 18-membered heteroaryl, diphenylamino, or substituted with one or more R b Substituted diphenylamine group; R b Each occurrence is independently of deuterium, fluorine, CN, C1-C12 alkyl, C1-C12 alkoxy, C3-C10 cycloalkyl, C6-C14 aryl, and is accompanied by one or more R. c Substituted C6-C14 aryl, 5- to 18-membered heteroaryl, and substituted with one or more R c Substituted 5- to 18-membered heteroaryl, diphenylamino, or substituted with one or more R c Substituted diphenylamine group; R c Each occurrence is independently of deuterium, fluorine, CN, C1-C12 alkyl, C1-C12 alkoxy, C3-C10 cycloalkyl, C6-C14 aryl, and is accompanied by one or more R. d Substituted C6-C14 aryl, 5- to 18-membered heteroaryl, and substituted with one or more R d Substituted 5- to 18-membered heteroaryl, diphenylamino, or substituted with one or more R d Substituted diphenylamine group; R d Each time it appears, it is independently deuterium, fluorine, C1-C12 alkyl, C1-C12 alkoxy, C3-C10 cycloalkyl, C6-C14 aryl, or is affected by one or more R groups. e Substituted C6-C14 aryl groups; R e Each time it appears, it is independently deuterium, fluorine, C1-C12 alkyl, C1-C12 alkoxy, C3-C10 cycloalkyl, or C6-C14 aryl; R 1 R 2 R 3 R 4 R 5 R 6 R 7 and R 8 Independent existence or R 1 R 2 R 3 R 4 R 5 R 6 R 7 and R 8 At least one of them forms a ring with the connected aromatic ring; The alkyl, alkoxy, cycloalkyl, aryl, and heteroaryl groups are optionally substituted with one or more substituents selected from the following: halogen, -CN, C1-C12 alkyl, C1-C12 alkoxy, C1-C12 haloalkyl, C3-C10 cycloalkyl, C6-C14 aryl, and 5- to 18-membered heteroaryl.

2. The organic light-emitting thin film material according to claim 1, characterized in that, The R a Each occurrence is independent of deuterium, fluorine, and C1-C2. 12 Alkyl, C1-C 12 Alkoxy, C3-C 10 cycloalkyl, with at least one C1-C 12 Alkyl-substituted phenyl, with at least one C1-C 12 Alkoxy-substituted phenyl, phenyl-C1~C 12 Alkyl, diphenylamino, with at least one C1-C 12 Alkyl-substituted diphenylamino group, carbazole group, or group with at least one C1-C 12 Alkyl-substituted carbazole group; Preferably, the R b Each occurrence is independent of deuterium, fluorine, and C1-C2. 12 Alkyl, C1-C 12 Alkoxy, C3-C 10 cycloalkyl, with at least one C1-C 12 Alkyl-substituted phenyl, with at least one C1-C 12 Alkoxy-substituted phenyl, phenyl-C1~C 12 Alkyl, diphenylamino, with at least one C1-C 12 Alkyl-substituted diphenylamino group, carbazole group, or group with at least one C1-C 12 Alkyl-substituted carbazole group; Preferably, the R c Each occurrence is independent of deuterium, fluorine, and C1-C2. 12 Alkyl, C1-C 12 Alkoxy, C3-C 10 cycloalkyl, with at least one C1-C 12 Alkyl-substituted phenyl, with at least one C1-C 12 Alkoxy-substituted phenyl, phenyl-C1~C 12 Alkyl, diphenylamino, with at least one C1-C 12 Alkyl-substituted diphenylamino group, carbazole group, or group with at least one C1-C 12 Alkyl-substituted carbazole group; Preferably, the R d Each occurrence is independent of deuterium, fluorine, and C1-C2. 12 Alkyl, C1-C 12 Alkoxy, C3-C 10 cycloalkyl, with at least one C1-C 12 Alkyl-substituted phenyl, with at least one C1-C 12 Alkoxy-substituted phenyl, carbazole, or alkyl-substituted phenyl groups with at least one C1-C bond 12 Alkyl-substituted carbazole group; Preferably, the R 1 R 2 R 3 R 4 R 5 R 6 R 7 and R 8 Independently, it is ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, hexyl, octyl, decyl, Methoxy, ethoxy, butoxy, hexoxy Cyclohexyl, adamantyl, phenyl, 2-methyl-phenyl, 4-methyl-phenyl, 4-ethyl-phenyl, 4-propyl-phenyl, 4-isopropylphenyl, 4-n-butylphenyl The wavy lines represent the connection sites of the functional groups; Preferably, the R 1 R 2 R 3 R 4 R 5 R 6 R 7 and R 8 Independently 2-methyl-phenyl, phenyl, The wavy lines represent the connection sites of the functional groups; Preferably, R 1 R 2 R 3 R 4 R 5 R 6 R 7 and R 8 At least one of them forms a ring structure with the connected aromatic ring as follows: The bond marked with an asterisk (*) is a bond shared with the aromatic ring. Preferably, R is selected from 3. The organic light-emitting thin film material according to claim 1 or 2, characterized in that, The boron-nitrogen compound is any one of the following compounds:

4. The organic light-emitting thin film material according to any one of claims 1-3, characterized in that, The host material includes a first host material and a second host material, wherein the first host material includes any one of the compounds shown in formulas H-1 to H-10; and the second host material includes any one of the compounds shown in formulas Ph-2CN-1 to Ph-2CN-6. Where X1, Y1, and Z1 are CH or N, and at most one of X1, Y1, and Z1 is N; where R 1H and R 2H Independently, it can be any of the following groups: Where X2, Y2, and Z2 are CH or N, and at most one of X2, Y2, and Z2 is N; Where R aH and R bH Independent of H, C1-C 20 Alkyl, C1-C 20 Alkoxy, C6-C 20 Aryl, C1-C 20 Alkyl-substituted C6-C 20 Aryl or C1-C 20 Alkoxy-substituted C6-C 20 Aryl group, * indicates the linkage site of the group; W 1 W 2 W 3 W 4 W 5 W 6 W 7 W 8 and W 9 Independently S or O; R 3H R 4H R 5H R 6H R 7H R 8H R 9H R 10H R 11H R 12H R 13H and R 14H It is independently H, deuterium, C1-C6 alkyl or C6-C24 aryl; Y1, Y2, Y3, Y4, Y5, Y6, Y7 and Y8 are independently O (oxygen) or S (sulfur); R s1 R s2 R s3 R s4 R s5 and R s6 It is independently C6-C24 aryl or C12-C36 heteroaryl; R si (i=7-39) are independently H, deuterium, C1-C6 alkyl, C1-C6 alkoxy or C6-C24 aryl.

5. The organic light-emitting thin film material according to any one of claims 1-4, characterized in that, The weight ratio between the first main material and the second main material is 1:20 to 20:1; Preferably, R s1 R s2 R s3 R s4 R s5 and R s6 Independently selected from any one of the following 24 groups: An asterisk (*) represents a linking site of a functional group. Preferably, R si (i = 7-39) Independently selected from any one of the following 5 groups: An asterisk (*) represents a linking site of a functional group. Preferably, the first host material is any one of the following compounds H1-1 to H1-254: Preferably, the second host material is any one of compounds from 2CN-1 to 2CN-60:

6. The organic light-emitting thin film material according to any one of claims 1-5, characterized in that, The doping material in the organic light-emitting thin film is a boron nitrogen compound of Formula I and Formula II; the host material is composed of any one of the dicyanophenyl derivatives of Formula 2CN-1 to 2CN-60 and any one of the carbazole derivatives of Formula H1-1 to H1-254; preferably, in the host material, the weight ratio between the dicyanophenyl derivative and the carbazole derivative is 1:20 to 20:

1. Preferably, the doping material in the organic light-emitting thin film is any one of the compounds shown in formula BN-1 to BN-272, and the host material is composed of any one of the compounds shown in formula Ph-2CN-1 to Ph-2CN-6 and any one of the compounds shown in formula H1-1 to H1-254; preferably, in the host material, the weight ratio between the compounds shown in formula Ph-2CN-1 to Ph-2CN-6 and the compounds shown in formula H1-1 to H1-254 is 1:20 to 20:1; Preferably, the doping material in the organic light-emitting thin film is any one of the compounds shown in formulas BN-1 to BN-272, and the host material is composed of any one of the dicyanophenyl derivatives shown in formulas 2CN-1 to 2CN-60 and any one of the compounds shown in formulas H1-1 to H1-254; preferably, in the host material, the weight ratio between the dicyanophenyl derivatives shown in formulas 2CN-1 to 2CN-60 and the carbazole derivatives shown in formulas H1-1 to H1-254 is 1:20 to 20:1; Preferably, the weight ratio of the host material to the dopant material in the organic light-emitting thin film is from 99.5:0.5 to 95.0:5.0; Preferably, the host material includes a first host material, a second host material and a third host material, wherein the first host material includes any one of compounds having the structure shown in formula Trz1-A to Trz6-A, the second host material includes any one of compounds having the structure shown in formula Trz1-A to Trz6-A, and the third host material includes any one of phosphorescent compounds containing metallic Pt as shown in formula Pt-1. Where R 1a R 1b R 2a R 2b R 3a and R 3b One or two of them are independent as R Tz The remaining elements are, independently and identically, hydrogen, deuterium, C1-C8 alkyl, C1-C8 alkoxy, or C6-C4. 18 Aryl, C1-C8 alkyl substituted C6-C 18 Aryl or C1-C8 alkoxy-substituted C6-C 18 aryl; R Tz It can be any of the substituents shown in the following formula: The asterisk represents the bonding site of the functional group; Preferably, the ratio of the compounds shown in Trz1-A, Trz2-A, Trz3-A, Trz4-A, Trz5-A or Trz6-A to the compounds shown in H-1, H-2, H-3, H-4, H-5, H-6, H-7, H-8, H9 or H-10 in the main material is 1:20 to 20:1; Preferably, the sum of the weights of the compounds shown in Trz1-A, Trz2-A, Trz3-A, Trz4-A, Trz5-A or Trz6-A and the compounds shown in H-1, H-2, H-3, H-4, H-5, H-6, H-7, H-8, H9 or H-10 is in the ratio of the weight of any phosphorescent compound containing metallic Ir or Pt as shown in formula Ir-1, formula Ir-2 and Pt-1 to a total weight of 100:3 to 100:

20. R tn (n=1-10) are independently hydrogen, deuterium, C1-C18 alkyl or C6-C18 aryl; R tn Any one of the groups in (n = 1-10) can form a ring with an aromatic ring or an aromatic heterocycle; preferably, the phosphorescent compound containing metal Pt is any one of the following compounds: Preferably, the compound having the structure shown in formula Trz1-A to Trz6-A is any one of the compounds shown in formula TRZ-1 to TRZ-86: Preferably, the composition of the main material includes the following three types: (1) any one of the compounds shown in formulas Trz1-A to Trz6-A, any one of the compounds shown in formulas H1-1 to H1-254, and any one of the phosphorescent compounds containing metal Pt as shown in formula Pt-1; (2) any one of the compounds shown in formulas TRZ-1 to TRZ-86, any one of the compounds with structures shown in formulas H-1 to H-10, and any one of the phosphorescent compounds containing metal Pt as shown in formula Pt-1; (3) any one of the compounds shown in formulas H1-1 to H1-254, any one of the compounds shown in formulas TRZ-1 to TRZ-86, and any one of the phosphorescent compounds containing metal Pt as shown in formula Pt-1. Preferably, the weight ratio between any one of the compounds shown in TRZ-1 to TRZ-86 and any one of the compounds shown in formulas H1-1 to H1-254 is 1:20 to 20:1, and the weight ratio of the sum of the weights of any one of the compounds shown in TRZ-1 to TRZ-86 and any one of the compounds shown in formulas H1-1 to H1-254 to the weight of any phosphorescent compound containing metallic Pt as shown in formula Pt-1 is 100:3 to 100:

20. Preferably, the weight ratio between the host material and the dopant material in the organic light-emitting thin film is from 99.5:0.5 to 95.0:5.

0. Preferably, the doping material in the organic light-emitting thin film is any one of the compounds shown in formula BN-1 to BN-272, and the host material is composed of any one of the compounds shown in formula H1-1 to H1-254, any one of the compounds shown in formula TRZ-1 to TRZ-86, and any phosphorescent compound containing metal Pt shown in formula Pt-1. Preferably, the weight ratio between any one of the compounds shown in TRZ-1 to TRZ-86 and any one of the compounds shown in formulas H1-1 to H1-254 is 1:20 to 20:1, and the weight ratio of the sum of the weights of any one of the compounds shown in TRZ-1 to TRZ-86 and any one of the compounds shown in formulas H1-1 to H1-254 to the weight of any phosphorescent compound containing metallic Pt as shown in formula Pt-1 is 100:3 to 100:

20. Preferably, the weight ratio between the host material and any one of the compound dopants shown in BN-1 to BN-272 in the organic light-emitting film is 99.5:0.5 to 95.0:5.

0.

7. An organic electroluminescent device, characterized in that, The organic electroluminescent device includes an anode and a cathode, and an organic thin film layer disposed between the anode and the cathode, the organic thin film layer comprising an organic light-emitting thin film material as described in any one of claims 1-8; Preferably, the organic thin film layer includes a light-emitting layer, an optional hole injection layer, an optional hole transport layer, an optional electron transport layer, and an optional electron injection layer, wherein at least one of the light-emitting layer, electron injection layer, electron transport layer, hole transport layer, and hole injection layer comprises the organic light-emitting thin film material as described in any one of claims 1-6. Preferably, the material of the light-emitting layer in the organic electroluminescent device comprises the organic light-emitting thin film material as described in any one of claims 1-6; Preferably, the organic electroluminescent device further includes an optional hole blocking layer, an optional electron blocking layer, and an optional capping layer.

8. The application of the organic electroluminescent device according to claim 7 in organic electroluminescent displays or organic electroluminescent lighting sources.

9. A method for preparing a boron-nitrogen compound, characterized in that, The boron nitrogen compound has the structure shown in Formula I or Formula II as claimed in claim 1, and the preparation method includes the following steps: (1) The raw material S undergoes a Suzuki coupling reaction with the raw material S1-Ai or S2-Ai to obtain the intermediate DF-Ri(I); (2) Treat intermediate DF-Ri(I) with lithium diisopropylamino, then mix with elemental iodine and react to obtain iodinated intermediate I-Ri(I); (3) Iodinated intermediate I-Ri(I) reacts with S1-Bi or S2-Bi to obtain intermediate Cz-Ri(I); (4) The intermediate Cz-Bi(I) reacts with the raw material S1-Ci or S2-Ci, and then reacts with methanesulfonic acid to obtain the intermediate Spiro-Ci(I); (5) The intermediate Spiro-Ci(I) reacts with boron tribromide to give a boron nitrogen compound with the structure shown in Formula I or Formula II; The reaction process is as follows:

10. The preparation method according to claim 9, characterized in that, The molar ratio of raw material S to raw material S1-Ai or S2-Ai in step (1) is 1:1 to 1:10; Preferably, the reaction in step (1) is carried out in the presence of a catalyst; Preferably, the catalyst is any one or a combination of at least two of tetraphenylphosphine palladium, [1,1'-bis(diphenylphosphine)ferrocene]palladium dichloride, or bis(diphenylphosphine)palladium dichloride; Preferably, the reaction in step (1) is carried out in the presence of an alkaline substance selected from potassium carbonate and / or sodium carbonate; Preferably, the reaction in step (1) is carried out in a solvent, which is a mixture of tetrahydrofuran and water; Preferably, the reaction in step (1) is carried out under reflux and the reaction time is 6 to 48 hours; Preferably, the molar ratio of lithium diisopropylamino to intermediate DF-Ri(I) in step (2) is 1:1 to 5:1; Preferably, the process of treating intermediate DF-Ri(I) with lithium diisopropylamino in step (2) is as follows: lithium diisopropylamino is added dropwise to the system containing intermediate DF-Ri(I), and the reaction is carried out to obtain intermediate DF-Ri(I) treated with lithium diisopropylamino. Preferably, the reaction temperature after adding lithium diisopropylamino is -80 to 0°C; the reaction time is 0.5 to 12 hours. Preferably, the molar ratio of elemental iodine to intermediate DF-Ri(I) in step (2) is 1:1 to 8:1; Preferably, the reaction after mixing with iodine in step (2) is carried out in an organic solvent, wherein the organic solvent is any one or a combination of at least two of tetrahydrofuran, 1,4-dioxane, diethyl ether, diphenyl ether, ethylene glycol dimethyl ether or ethylene glycol diethyl ether; Preferably, the reaction after mixing with iodine in step (2) is carried out at room temperature for 6 to 48 hours; Preferably, the molar ratio of the iodinated intermediate I-Ri(I) to S1-Bi or S2-Bi in step (3) is 1:2 to 1:10; Preferably, the reaction in step (3) is carried out in the presence of an alkaline substance, which is selected from any one or a combination of at least two of cesium carbonate, potassium carbonate, sodium carbonate, lithium carbonate, potassium phosphate or potassium acetate. Preferably, the reaction in step (3) is carried out in an organic solvent selected from any one or a combination of at least two of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide or hexamethylphosphoric triamine; Preferably, the reaction temperature in step (3) is 80–180°C; Preferably, the molar ratio of the intermediate Cz-Bi(I) in step (4) to the raw material S1-Ci or S2-Ci is 1:1 to 1:10; Preferably, the reaction in step (4) is carried out in the presence of n-butyllithium; Preferably, a hexane solution of n-butyllithium is added to a solution containing intermediate Cz-Bi(I) to carry out the reaction, and then raw material S1-Ci or S2-Ci is added to carry out the reaction. Preferably, the hexane solution of n-butyllithium is added to a solution containing intermediate Cz-Bi(I) at -80 to 0°C; Preferably, the reaction temperature for adding the hexane solution of n-butyllithium to the solution containing the intermediate Cz-Bi(I) is -80 to 0°C, and the reaction time is 0.5 to 12 hours. Preferably, the solution containing intermediate Cz-Bi(I) is a tetrahydrofuran solution containing intermediate Cz-Bi(I); Preferably, the reaction temperature for adding raw material S1-Ci or S2-Ci is room temperature, and the reaction time is 6 to 48 hours; Preferably, the molar ratio of intermediate Cz-Bi(I) to methanesulfonic acid in step (4) is 1:1 to 1:20; Preferably, the reaction temperature with methanesulfonic acid in step (4) is room temperature, and the reaction time is 1 to 24 hours; Preferably, the reaction with methanesulfonic acid in step (4) is carried out in an organic solvent, wherein the organic solvent is any one or a combination of at least two of dichloromethane, trichloromethane, dichloroethane or tetrachloroethane; Preferably, the lithiation reagent used in the lithiation stage of the lithiation-boration-cyclization reaction in step (5) is tert-butyllithium; Preferably, the molar ratio of tert-butyllithium to intermediate Spiro-Ci(I) is 1:1 to 1:3; Preferably, in the lithiation-boration-cyclization reaction described in step (5), the lithiation reagent is added to the reaction system containing intermediate 5 at -80 to 0°C during the lithiation stage; Preferably, in step (5), the lithiation stage of the lithiation-boration-cyclization reaction is carried out in an organic solvent, wherein the organic solvent is tert-butylbenzene; Preferably, the reaction temperature of the lithiation stage in the lithiation-boration-cyclization reaction in step (5) is 0 to 80°C, and the reaction time is 0.5 to 12 hours; Preferably, the borating agent used in the boration stage of the lithiation-boration-cyclization reaction in step (5) is boron tribromide; Preferably, the molar ratio of boron tribromide to intermediate Spiro-Ci(I) is 1:1 to 1:5; Preferably, the boration stage in the lithiation-boration-cyclization reaction in step (5) is carried out at room temperature for a reaction time of 0.5 to 12 hours; Preferably, the cyclization stage in the lithiation-boration-cyclization reaction in step (5) is carried out in the presence of N,N-diisopropylethylamine or 1,2,2,6,6-pentamethylpiperidine; Preferably, the molar ratio of N,N-diisopropylethylamine or 1,2,2,6,6-pentamethylpiperidine to intermediate Spiro-Ci(I) is 1:2 to 1:10; Preferably, the N,N-diisopropylethylamine is added to the reaction system at a temperature of -80 to 30°C; Preferably, the cyclization stage of the lithiation-boration-cyclization reaction in step (5) is carried out at 80–160 °C.

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