Light-emitting compound, light-emitting layer preparation material, organic light-emitting device, and preparation method

Abstract

The application discloses a light-emitting compound, a light-emitting layer preparation raw material, an organic light-emitting device and a preparation method, and belongs to the technical field of display. The light-emitting compound comprises an electron acceptor group and at least two different electron donor groups; the electron acceptor group comprises an anthraquinone group; the at least two different electron donor groups are connected with at least two of the 1st to 8th positions of the anthraquinone group; and the electron donor group comprises at least one of a diarylamine group, a triarylamine group, a carbazole group and a phenylcarbazole group. The light-emitting compound connects the at least two different electron donor groups with multiple positions on the anthraquinone group, so that the light-emitting compound has a delayed fluorescence property, can be used as an organic light-emitting material, and can be used as a sensitizer in a sensitized device. Since multiple electron donor groups are used and they are asymmetrically distributed, the energy level structure of the triplet state and the singlet state of the light-emitting compound molecule is complicated, which is beneficial to efficient reverse intersystem crossing of the light-emitting compound.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of display, in particular to a light-emitting compound, a light-emitting layer preparation raw material, an organic light-emitting device and a preparation method. BACKGROUND

[0002] An organic light-emitting diode (OLED) is a current-type semiconductor light-emitting device based on organic light-emitting materials. At present, OLED devices usually use organic light-emitting materials with thermal activated delayed fluorescence (TADF) characteristics. Such TADF-based organic light-emitting materials include both electron donor (D) groups and electron acceptor (A) groups, and the energy gap between the singlet state (S1) and the triplet state (T1) (ΔEs) is very small. Thus, T1-state excitons can emit fluorescence by a reverse intersystem crossing process under the action of thermal energy, so that the theoretical photoelectric conversion efficiency reaches 100%, and thus the OLED device obtains 100% internal quantum efficiency.

[0003] The related art provides TADF-based organic light-emitting materials, which generally include the following molecular configurations: (1) electron donor-electron acceptor configuration (referred to as D-A configuration), (2) electron donor-electron acceptor-electron donor configuration (referred to as D-A-D configuration). The electron acceptor group is anthraquinone, and the acceptor group is carbazole, diphenylamine, triphenylamine, phenothiazine, etc.

[0004] However, the organic light-emitting material involved in (1) has a very strong triple-triple annihilation (TTA) effect, and the triplet and singlet energy level structures of such materials are relatively simple, which is not conducive to efficient reverse intersystem crossing. The organic light-emitting material involved in (2) is strongly dependent on the polarity and dipole moment of the solvent, which limits its application, and the triplet and singlet energy level structures of such materials are also relatively simple, which is not conducive to efficient reverse intersystem crossing.

[0005] DISCLOSURE

[0006] In view of this, the present disclosure provides a light-emitting compound, a light-emitting layer preparation raw material, an organic light-emitting device and a preparation method, which can solve the above technical problems.

[0007] Specifically, the technical solutions include the following:

[0008] In an aspect, a light-emitting compound is provided, the light-emitting compound comprising: an electron acceptor group, at least two different electron donor groups;

[0009] The electron acceptor group comprises an anthraquinone group, and the at least two different electron donor groups are respectively connected to at least two of positions 1-8 of the anthraquinone group;

[0010] The electron donor group comprises at least one of a diarylamine group, a triarylamine group, a carbazole group, and a phenylcarbazole group.

[0011] The light-emitting compound provided by the embodiments of the present disclosure connects at least two different electron donor groups to multiple positions of an anthraquinone group, introduces different electron donor groups into the anthraquinone group in an asymmetric manner, so that the light-emitting compound has a delayed fluorescence property, and can be used not only as an organic light-emitting material but also as a sensitizer in a sensitized device. Because multiple electron donor groups are used and they are asymmetrically distributed, this complicates the energy level structure of the excited triplet state and the excited singlet state of the light-emitting compound molecule, which facilitates efficient reverse intersystem crossing of the light-emitting compound.

[0012] In some possible implementations, the light-emitting compound further comprises: at least one light-emitting behavior regulating group, the light-emitting behavior regulating group being connected to a position not occupied by the electron donor group among positions 1-8 of the anthraquinone group;

[0013] The light-emitting behavior regulating group comprises at least one of D, F, Cl, CN, CH3, an aryl group, and a heteroaryl group.

[0014] In some possible implementations, the electron acceptor group further comprises: one or two substituent groups, the substituent group substituting one or two O atoms in positions 9 and 10 of the anthraquinone group;

[0015] The substituent group comprises at least one of a dicyanomethylidene group and an arylacetonitrile group.

[0016] In some possible implementations, the light-emitting compound has a chemical structural formula as shown in the following:

[0017]

[0018] wherein X 1 and X 2 are each independently selected from an oxygen atom, a dicyanomethylidene group, or an arylacetonitrile group;

[0019] R 1 is the electron acceptor group, and R 8 is the electron donor group; 1 R 8each independently selected from H, D, F, CI, CN, CH3, substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C3-C30 heteroaryl.

[0020] In some possible implementations, the chemical formula of the electron donor group is as follows: LNAr1Ar2;

[0021] wherein L is selected from a single bond, substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C3-C30 heteroaryl;

[0022] Ar1and Ar2are each independently selected from substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C3-C30 heteroaryl, wherein Ar1and Ar2are each independently, or Ar1and Ar2, through a linking group, form a conjugated unit, the linking group is selected from a single bond, -O-, -S-, -C(CH3)2-, or -C(C6H5)2-.

[0023] In some possible implementations, the Ar1and the Ar2are each independently selected from one of the following groups:

[0024]

[0025]

[0026] wherein Y 11 , Y 12 , Y 13 , Y 14 , Y 15 , Y 16 , Y 17 , Y 18 , Y 19 , Y 110 , Y 111 , Y 112 are each independently selected from N or C-RY;

[0027] T 1 is selected from O, S, N-RT1, CRT2RT3, or SiRT2RT3;

[0028] RY, RT1, RT2, RT3are each independently selected from hydrogen, deuterium, cyano, halogen, substituted or unsubstituted C1-C4 alkyl, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C3-C18 heteroaryl, or C6-C18 arylamine.

[0029] In some possible implementations, L is selected from a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted pyridylene group, and a substituted or unsubstituted fluorene group.

[0030] In another aspect, a light-emitting layer preparation raw material is provided, and the light-emitting layer preparation raw material includes any of the light-emitting compounds described above.

[0031] In some possible implementations, the light-emitting layer preparation raw material further includes a host light-emitting material including at least one of triphenylene, carbazole, dithiophene, difuran, diselenophene, aza-triphenylene, aza-carbazole, aza-dithiophene, aza-difuran, and aza-diselenophene.

[0032] In some possible implementations, the light-emitting layer preparation raw material further includes a fluorescent material.

[0033] In another aspect, an organic light-emitting device is provided, and the organic light-emitting device includes a light-emitting layer prepared from any of the light-emitting layer preparation raw materials described above.

[0034] In another aspect, a preparation method of a light-emitting compound is provided, and the light-emitting compound is as shown in any of the above.

[0035] The preparation method of the light-emitting compound includes: providing at least two different electron donor compounds, and respectively performing boron ester or boric acid treatment on the at least two different electron donor compounds to obtain at least two boric acid or boric acid ester form electron donor compounds.

[0036] The at least two boric acid or boric acid ester form electron donor compounds are sequentially introduced into an anthraquinone compound by a Suzuki coupling reaction to obtain the light-emitting compound.

[0037] In some possible implementations, the anthraquinone compound includes an anthraquinone group and two halogen substituents, and the two halogen substituents are respectively connected to two symmetrical positions in positions 1-8 of the anthraquinone group.

[0038] In some possible implementations, the anthraquinone compound is prepared by the following method:

[0039] Derivatives of benzene and phthalic anhydride are subjected to a Friedel-Crafts reaction to obtain the anthraquinone compound.

[0040] In some possible implementations, the derivatives of benzene have the following chemical structure:

[0041] In some possible implementations, the derivatives of benzene have the following chemical structure:

[0042] B1, B2, B3, B4 are each independently selected from the group consisting of hydrogen, D, F, C1-C20 linear or branched alkyl;

[0043] The chemical structure of the derivative of the phthalic anhydride is as follows:

[0044]

[0045] A1, A2, A3, A4 are each independently selected from one of methyl, fluorine, chlorine, bromine. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 The structural schematic diagram of an exemplary organic light-emitting device provided by the embodiments of the present disclosure.

[0047] The reference signs respectively represent:

[0048] 1-anode,

[0049] 2-hole injection layer,

[0050] 3-hole transport layer,

[0051] 4-hole transport / electron blocking layer,

[0052] 5-emitting layer,

[0053] 6-electron transport layer,

[0054] 7-electron injection layer,

[0055] 8-cathode. DETAILED DESCRIPTION

[0056] In order to make the technical solutions and advantages of the present disclosure clearer, the embodiments of the present disclosure will be further described in detail below with reference to the drawings.

[0057] According to a first aspect of the embodiments of the present disclosure, a light-emitting compound is provided, which comprises: an electron acceptor group, at least two different electron donor groups; wherein the electron acceptor group comprises an anthraquinone group, and the at least two different electron donor groups are respectively connected to at least two of positions 1-8 of the anthraquinone group.

[0058] The number positions on the central benzene ring of the anthraquinone group involved in the embodiments of the present disclosure are arranged as shown below, wherein the electron donor groups occupy at least two of positions 1-8:

[0059]

[0060] The number of electron donor groups in the luminescent compound provided by the embodiments of the present disclosure is at least two, for example, two, three, four, five, six, etc., and at least two of the electron donor groups are different.

[0061] In some examples, the luminescent compound includes two different electron donor groups, which respectively occupy the 2nd and 6th positions of the anthraquinone group, or which respectively occupy the 1st and 5th positions of the anthraquinone group.

[0062] In the embodiments of the present disclosure, the electron donor group includes at least one of a diarylamine group, a triarylamine group, a carbazole group, and a phenylcarbazole group. Such electron donor groups are excellent and stable electron donor groups.

[0063] The luminescent compound provided by the embodiments of the present disclosure connects at least two different electron donor groups to multiple positions of the anthraquinone group in an asymmetric manner to introduce different electron donor groups into the anthraquinone group, so that the luminescent compound has a delayed fluorescence property and can be used not only as an organic luminescent material but also as a sensitizer in a sensitized device. Because multiple electron donor groups are used and they are asymmetrically distributed, this complicates the energy level structure of the excited triplet state and the excited singlet state of the luminescent compound molecule, which facilitates efficient reverse intersystem crossing of the luminescent compound.

[0064] Further, the luminescent compound provided by the embodiments of the present disclosure further includes at least one luminescence behavior regulating group connected to a position of the 1st to 8th positions of the anthraquinone group that is not occupied by an electron donor group; the luminescence behavior regulating group includes at least one of D (deuterium), F (fluorine), Cl (chlorine), CN (cyan), CH3 (methyl), an aryl group, and a heteroaryl group.

[0065] For example, the 2nd and 6th positions of the anthraquinone group are occupied by different electron donor groups, and the luminescence behavior regulating group can occupy at least one of the 1st, 3rd, 4th, 5th, 7th, and 8th positions of the anthraquinone group.

[0066] For D, F, Cl, CN, and CH3, these luminescence behavior regulating groups regulate the luminescence behavior of the luminescent compound based on the following action mechanism:

[0067] D (deuterium) as a heavy atom (relative to H (hydrogen)) is beneficial to optimizing the triplet energy level of the luminescent compound, thereby achieving the effect of optimizing the photophysical properties of the luminescent compound;

[0068] F, Cl, CN have typical electronegativity, which can effectively improve the electron-deficient properties of anthraquinone unit, thereby forming a stronger electron acceptor, and obtaining higher photoluminescence quantum efficiency (PLQY) (for luminescent compounds, under the same molecular structure and the same electron donor coupling, a strong acceptor is more conducive to improving PLQY);

[0069] CH3 can significantly inhibit the radiative transition of the adjacent donor unit in the excited state, thereby improving the luminescent efficiency of the luminescent compound. In addition, CH3 can affect the degree of electron cloud overlap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of the electron donor unit and the anthraquinone acceptor, further improving the reverse intersystem crossing and optimizing the light emission performance of the corresponding luminescent compound.

[0070] For aryl and heteroaryl, these luminescent behavior regulating groups achieve the regulation of the luminescent behavior of the luminescent compound based on the following action mechanism:

[0071] Compared with methyl, aryl and heteroaryl have larger steric effect, conjugation effect, etc., which not only have similar effects as methyl, but also can fine-tune the energy level of the anthraquinone acceptor to optimize the light emission performance of the luminescent compound. It can be seen that by synergistic effect of the electron donor group and the luminescent behavior regulating group, they have different energy levels and electron transfer properties, which can effectively affect the PLQY, singlet-triplet energy level difference, reverse intersystem crossing, etc. of the luminescent compound.

[0072] In some implementations, the electron acceptor group provided by the embodiments of the present disclosure further includes: one or two substituent groups, which substitute the O atom at least one of the 9th and 10th positions of the anthraquinone group; wherein the substituent group includes at least one of dicyanomethylidene and arylacetonitrile group, which has electron-withdrawing function and is beneficial to change the LUMO energy level of the luminescent compound, but does not affect its TADF property.

[0073] For dicyanomethylidene, its chemical structural formula is as follows: Wherein, the dotted line represents the connection site of the group.

[0074] For arylacetonitrile group, its chemical structural formula is as follows: Wherein, the dotted line represents the connection site of the group.

[0075] R 0hydrogen, deuterium, tritium, cyano, halogen, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C2-C10 alkenyl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C3-C30 heteroaryl, etc.

[0076] Based on the above, the chemical structural formula of the luminescent compound provided in the embodiments of the present disclosure is shown as follows:

[0077]

[0078] wherein X 1 and X 2 each independently is oxygen, dicyanomethylene, or arylacetonitrile;

[0079] R 1 -R 8 At least two of R 1 -R 8 each independently is selected from H, D, F, Cl, CN, CH3, substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C3-C30 heteroaryl. That is, at least two of R 1 -R 8 each independently is selected from H, D, F, Cl, CN, CH3, substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C3-C30 heteroaryl. That is, at least two of R 1 -R 8 The other groups in R

[0080] In some examples, there are two or more electron donor groups, and at least two different electron donor groups exist, the chemical general formula of the electron donor group suitable for the embodiments of the present disclosure is shown as follows: LNAr1Ar2; wherein L is selected from one of a single bond, substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C3-C30 heteroaryl; Ar1 and Ar2 are each independently selected from substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C3-C30 heteroaryl, wherein Ar1 and Ar2 are each independently or Ar1 and Ar2 form a conjugated unit through a linking group selected from one of a single bond, -O-, -S-, -C(CH3)2-, -C(C6H5)2-.

[0081] Further, Ar1 and Ar2 are each independently selected from one of the following groups (the dotted line in the following groups represents the connecting site of the group):

[0082]

[0083] or

[0084]

[0085] wherein Y 11 , Y 12 , Y 13 , Y 14 , Y 15 , Y 16 , Y 17 , Y 18 , Y 19 , Y 110 , Y 111 , Y 112 are each independently selected from N or C-RY;

[0086] T 1 is selected from O, S, N-RT1, CRT2RT3, or SiRT2RT3;

[0087] RY, RT1, RT2, RT3are each independently selected from hydrogen, deuterium, cyano, halogen, substituted or unsubstituted C1-C4alkyl, substituted or unsubstituted C6-C18aryl, substituted or unsubstituted C3-C18heteroaryl, or C6-C18arylamino. The C1-C4alkyl can be a straight chain alkyl or a branched alkyl. When two or more RYgroups are included in the Ar1group and the Ar2group, the multiple RYgroups are not connected to each other, or at least two adjacent RYgroups are connected by a chemical bond to form a ring.

[0088] The luminescent compound provided by the embodiments of the present disclosure has the above chemical structure. By adjusting the structure and position of R 1 -R 4 and R 5 -R 8 groups, the luminescent compound molecule has a high triplet energy level, a small ΔEST, a high PLQY, and a high glass transition temperature. Thus, when the luminescent compound is used in an OLED device, the overall performance and light-emitting efficiency of the OLED device are improved.

[0089] As mentioned above, the C1-C4alkyl, C6-C18aryl, and C3-C18heteroaryl can be substituted by a substituent. Exemplarily, the substituent suitable for the embodiments of the present disclosure includes but is not limited to deuterium, fluorine, chlorine, bromine, iodine, cyano, R'-substituted or unsubstituted C1-C4straight chain or branched alkyl, R'-substituted or unsubstituted C6-C18aryl, R'-substituted or unsubstituted C3-C18heteroaryl, C6-C18arylamino, and the like. For R', it includes but is not limited to deuterium, fluorine, chlorine, bromine, iodine, cyano, and the like.

[0090] In some examples, Ar1and Ar2are each independently one of the following groups (the groups shown below can be unsubstituted or substituted):

[0091]

[0092]

[0093] As mentioned above, L involved in the electron donor group is selected from one of a single bond, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group, for example, L is selected from a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted pyridylene group, or a substituted or unsubstituted fluorene group.

[0094] If the above-mentioned phenylene group, biphenylene group, naphthylene group, pyridylene group, or fluorene group includes a substituent, the substituent suitable for use is selected from deuterium, fluorine, chlorine, bromine, iodine, cyano, or a C1-C4 linear or branched alkyl group.

[0095] The substituent involved in the electron donor group can be located on the bridging unit between the electron donor group and the electron acceptor group, so that it can act as a steric hindrance structure, effectively inhibiting energy dissipation caused by molecular vibration of the light-emitting compound in the excited state, greatly improving the light-emitting performance of the light-emitting compound.

[0096] In some examples, the electron donor group provided by the embodiments of the present disclosure adopts one of the groups having the chemical structural formula shown below, wherein the dashed line in the chemical structural formula below represents the connection site of the group:

[0097]

[0098]

[0099]

[0100]

[0101] According to another aspect of the embodiments of the present disclosure, a preparation method of a light-emitting compound is also provided, wherein the light-emitting compound is as shown in any one of the above-mentioned embodiments of the present disclosure;

[0102] The preparation method of the light-emitting compound includes: providing at least two different electron donor compounds, and performing boron ester or boron acid treatment on the at least two different electron donor compounds respectively to obtain at least two electron donor compounds in the form of boronic acid or boronic ester;

[0103] The electron donor compound in the form of boronic acid or boronic ester is introduced into the anthraquinone compound by Suzuki coupling reaction to obtain the luminescent compound.

[0104] The electron donor compound in the form of boronic acid or boronic ester is introduced into the anthraquinone compound by Suzuki coupling reaction to obtain the luminescent compound. The Suzuki coupling reaction is catalyzed by a catalyst, for example, the catalyst includes but is not limited to Pd(PPh3)4 (tetrakis(triphenylphosphine)palladium), Pd-132 (dichlorobis-(4-dimethylaminophenyl)phosphine palladium (II)) and the like.

[0105] The anthraquinone compound can be a commercial anthraquinone material or a self-made anthraquinone material, which is exemplified as follows.

[0106] For the commercial anthraquinone compound, in some examples, the anthraquinone compound includes an anthraquinone group and two halogen substituents, and the two halogen substituents are connected to two symmetrical positions of the anthraquinone group.

[0107] For example, the anthraquinone compound includes but is not limited to 2,6-dibromoanthraquinone or 1,5-dichloroanthraquinone, and the synthesis route of the luminescent compound obtained by Suzuki coupling reaction of 2,6-dibromoanthraquinone and two different electron donor groups (D1 and D2) is as follows:

[0108]

[0109] For 1,5-dichloroanthraquinone, the synthesis route of the luminescent compound obtained by Suzuki coupling reaction of 1,5-dichloroanthraquinone and two different electron donor groups (D1 and D2) is as follows:

[0110]

[0111] The preparation method of the luminescent compound provided by the embodiments of the present disclosure uses an easily obtained commercial anthraquinone raw material to construct an anthraquinone unit that is easy to functionalize, which is beneficial to the structural expansion, photophysical performance regulation and optimization of the luminescent compound. The Suzuki coupling reaction has the advantages of mild reaction conditions, simple operation steps and high yield, so that the preparation method of the luminescent compound is simple and easy to operate, and is convenient for large-scale popularization and application.

[0112] The Suzuki coupling reaction is a common reaction type in the art. In the Suzuki coupling reaction, potassium carbonate can be used to provide an alkaline environment, tetrabutylammonium bromide can be used as a phase transfer catalyst, and an organic solvent such as toluene can be used as a reaction solvent.

[0113] For the anthraquinone material prepared by self, in some examples, the anthraquinone compound is prepared by the following method:

[0114] The derivative of benzene and the derivative of phthalic anhydride are subjected to Friedel-Crafts alkylation (F-C reaction) to obtain the anthraquinone compound.

[0115] The chemical structural formula of the derivative of benzene is as follows:

[0116]

[0117] B1, B2, B3, B4 are each independently selected from hydrogen, D, F, C1-C20 straight chain or branched alkyl.

[0118] The chemical structural formula of the derivative of phthalic anhydride is as follows:

[0119]

[0120] A1, A2, A3, A4 are each independently selected from methyl, fluorine, chlorine, or bromine.

[0121] The route for synthesizing the anthraquinone compound by F-C reaction of the derivative of benzene and the derivative of phthalic anhydride is as follows:

[0122]

[0123] The anthraquinone compound has multiple sites, and by subjecting different sites on the anthraquinone compound to Suzuki coupling reaction as shown above, a luminescent compound having an electron donor group at a specific site can be obtained, which makes the luminescent compound more diversified in luminescent behavior.

[0124] According to still another aspect of the embodiments of the present disclosure, a luminescent layer preparation raw material is also provided, which comprises any one of the luminescent compounds of the embodiments of the present disclosure.

[0125] The luminescent layer preparation raw material provided by the embodiments of the present disclosure can be used in OLED devices to form a luminescent layer, and the luminescent compound can be used as an emission dopant therein (that is, other compounds in the luminescent layer are used as host luminescent materials, and the luminescent compound is used as a dopant), and the luminescent compound can also be used as a sensitization aid for other luminescent units in the luminescent layer (that is, the luminescent layer includes a host luminescent material, a luminescent compound and other luminescent components, and the host luminescent material and the luminescent compound are used together to promote the luminescence of the other luminescent components).

[0126] In some examples, the luminescent layer preparation raw material provided by the embodiments of the present disclosure further includes a host luminescent material, the host luminescent material including at least one of the following groups: triphenylene, carbazole, dibenzothiophene, dibenzofuran, dibenzoselenophene, azatriphenylene, azacarbazole, azo-dibenzothiophene, azo-dibenzofuran, azo-dibenzoselenophene.

[0127] For example, the host luminescent material includes but is not limited to a compound having the following chemical formula:

[0128]

[0129] In some examples, the mass ratio of the host luminescent material to the luminescent compound is 100:(1-40), for example, which includes but is not limited to: 100:2, 100:3, 100:4, 100:5, 100:6, 100:7, 100:8, 100:9, 100:10, 100:15, 100:18, 100:20, 100:25, 100:30, etc.

[0130] The host luminescent material of the above chemical formula used by the embodiments of the present disclosure is more matched with the energy level of the luminescent compound, and both the host luminescent material and the luminescent compound can capture the triplet excitons entering the luminescent layer, the triplet excitons and singlet excitons captured by the host luminescent material are preferentially injected into the luminescent compound, the luminescent compound is excited into its excited state, and the triplet excited state excitons of the luminescent compound return to the singlet excited state of the luminescent compound in the form of reverse intersystem crossing, and then emit light in the form of singlet excited state radiation transition. The fluorescence emitted by the luminescent compound is referred to as the luminescence of the OLED device in the absence of a narrower band gap fluorescence.

[0131] Further, the luminescent layer preparation raw material provided by the embodiments of the present disclosure further includes a fluorescent material, the fluorescent material being capable of emitting a narrower band gap fluorescence, so that the fluorescent material cooperates with the host luminescent material and the luminescent compound, the fluorescence emitted by the luminescent compound is absorbed by the fluorescent material in the form of fluorescent resonance energy transfer, and thereafter, the fluorescent material converts from its excited state to the ground state and emits fluorescent light, further improving the luminescence effect of the luminescent layer.

[0132] In some examples, the fluorescent material includes but is not limited to a compound having the following chemical formula:

[0133]

[0134]

[0135] In some examples, the mass ratio of the host light-emitting material, the light-emitting compound, and the fluorescent material is 100:(1-40):(0.1-5), and the mass of the fluorescent material therein includes but is not limited to 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.5, etc.

[0136] According to still another aspect of the embodiments of the present disclosure, an organic light-emitting device (OLED device for short) is also provided, which comprises a light-emitting layer prepared from any of the light-emitting layer preparation materials mentioned above.

[0137] The OLED device comprises other functional layers in addition to the light-emitting layer, for example, as shown in the following structure: Figure 1 As shown in the structure, the OLED device provided by the embodiments of the present disclosure comprises, from bottom to top, an anode 1, a hole injection layer 2, a hole transport layer 3, a hole transport / electron blocking layer 4, a light-emitting layer 5, an electron transport layer 6, an electron injection layer 7, and a cathode 8, wherein the anode 1 is formed on a substrate, which can be, for example, a glass substrate, a ceramic substrate, etc.

[0138] The anode 1, the hole injection layer 2, the hole transport layer 3, the hole transport / electron blocking layer 4, the electron transport layer 6, the electron injection layer 7, and the cathode 8 can each use a material commonly used in the art, which will be described exemplarily as follows:

[0139] In some examples, the material of the anode 1 includes but is not limited to the following: indium tin oxide (ITO) conductive glass, Au, transparent conductive polymers (such as polyaniline, etc.), etc.

[0140] In some examples, the material of the cathode 8 includes but is not limited to the following: a single-layer metal cathode (such as Ag, Al, Li, Mg, Ca, In, etc.); an alloy cathode (such as a Mg-Ag alloy cathode, a Li-Al alloy electrode, etc.); a layered cathode composed of a thin layer of an insulating material such as LiF, Li2O, MgO, Al2O3, etc. and a thicker Al layer covering thereon.

[0141] For the hole injection layer 2, it includes but is not limited to HAT(CN)6, which has the chemical structure shown as follows:

[0142]

[0143] For the hole transport layer 3, it includes but is not limited to 4,4'-cyclohexyl di[N,N-di(4-methylphenyl)aniline] (TAPC for short), which has the chemical structure shown as follows:

[0144]

[0145] For the hole transport / electron blocking layer 4, it includes but is not limited to aromatic polyamine compounds, for example, 4,4',4"-tris(carbazol-9-yl)triphenylamine (abbreviated as TCTA), which has the chemical structure as shown below:

[0146]

[0147] For the electron transport layer 6, it includes but is not limited to 1,3,5-tris[(3-pyridyl)-3-phenyl]benzene (abbreviated as TmPyPB), wherein TmPyPB has the chemical structure as shown below:

[0148]

[0149] For the electron injection layer 7, it includes but is not limited to 8-hydroxyquinolinolato-lithium (LiQ) and the like.

[0150] In some examples, the raw materials for preparing the light-emitting layer 5 include a host light-emitting material and the light-emitting compound as described above in the embodiments of the present disclosure, for example, the mass ratio of the host light-emitting material to the light-emitting compound is 100:(1-40).

[0151] Exemplarily, the organic light-emitting device includes but is not limited to computers, tablets, televisions, telephones, virtual reality or augmented reality displays, and the like.

[0152] The embodiments of the present disclosure will be further described below through specific examples:

[0153] Example 1

[0154] This example 1 provides a light-emitting compound M1, which has the chemical structure as shown below:

[0155]

[0156] The synthesis route of the light-emitting compound M1 is as shown below:

[0157]

[0158] The preparation steps of the light-emitting compound M1 are as shown below:

[0159] Compound (1) (3.66 g, 10.0 mmol), 4-(diphenylamino)benzeneboronic acid (compound (2), 5.0 g, 17.3 mmol), potassium carbonate (3.0 g, 21.6 mmol), tetrabutylammonium bromide (50 mg) were placed in a two-necked flask, and toluene (80 mL) and water (20 mL) were added to the two-necked flask. After purging with nitrogen for 10-15 min, Pd(PPh3)4 catalyst (tetrakis(triphenylphosphine)palladium, 120 mg) was added to the two-necked flask, and then the Suzuki coupling reaction was carried out under nitrogen protection. After reaction at 90°C for 12 h, the reaction system was cooled to room temperature, and then extracted with dichloromethane and water (dichloromethane was used to dissolve the organic components, and water was used to dissolve the salts). After column chromatography by spinning off the solvent, compound (3) was obtained, and the mass of compound (3) was 4.24 g, with a yield of 79%.

[0160] Compound (3) (3.16 g, 6.0 mmol), 9-phenyl-carbazole-3-boronic acid (compound (4), 2.16 g, 7.2 mmol), potassium carbonate (1.68 g, 12.0 mmol), tetrabutylammonium bromide (30 mg) were placed in a two-necked flask, and toluene (60 mL), ethanol (15 mL) and water (15 mL) were added to the two-necked flask. After purging with nitrogen for 10-15 min, Pd-132 catalyst (dichlorobis-(4-dimethylaminophenyl) palladium(II), 8 mg) was added to the two-necked flask, and then the Suzuki coupling reaction was carried out under nitrogen protection. After reaction at 85°C for 3 h, the reaction system was cooled to room temperature, and then extracted with dichloromethane / water. After column chromatography by spinning off the solvent, the luminescent compound M1 was obtained (mass 3.6 g, yield 86%).

[0161] The luminescent compound M1 was subjected to nuclear magnetic resonance hydrogen spectrum and high resolution mass spectrum tests, and the test parameters are as follows:

[0162] 1 H NMR (CDCl3, 500 MHz): δ (ppm) 8.80 (s, 1H), 8.56 (s, 1H), 8.42-8.38 (m, 2H), 8.20-8.16 (m, 8H), 7.66 (m, 6H), 7.32-7.29 (m, 6H), 7.18-7.16 (m, 4H), 7.06 (m, 4H); HRMS m / z: 692.2642 [M] + According to the above test parameters, the chemical structural formula of the luminescent compound M1 is consistent with the above chemical structural formula.

[0163] This embodiment 1 introduces two different electron donor groups asymmetrically by two consecutive high-yield Suzuki reactions, so that the light-emitting compound M1 has a high photoluminescence quantum efficiency (PLQY), which is manifested in that the light-emitting compound M1 not only has a high PLQY in the light-emitting layer, and its PLQY in different solvents also has a large increase. It is tested that the light-emitting compound M1 exhibits an external quantum efficiency (EQE) of more than 18% in an OLED device.

[0164] It is found that the reasons for the light-emitting compound M1 to obtain the above beneficial effects include that in the M1 molecule, the triphenylamine structure can effectively make the M1 molecule have a suitable fluorescent light-emitting wavelength, the phenyl-substituted carbazole structure contributes less to the highest occupied molecular orbital (HOMO) energy level of the M1 molecule, but can effectively regulate the energy level splitting of the triplet excited state and the singlet excited state of the M1 molecule, so that the energy level difference between the singlet state and the triplet state is smaller, which has the following very beneficial effects on the photophysics of the M1 molecule: 1) the excited state intersystem crossing and reverse intersystem crossing energy level transition probability of the M1 molecule is improved, effectively improving the delayed fluorescence light-emitting efficiency, 2) the triplet-triplet annihilation of the M2 molecule is effectively suppressed.

[0165] It can be seen that the light-emitting compound M1 provided by embodiment 1 uses a commercial anthraquinone raw material to synthesize an asymmetric TADF molecule, and two different electron donor groups are asymmetrically distributed relative to the electron acceptor group, in order to achieve the purpose of regulating the above-mentioned HOMO energy level, triplet excited state and charge transport function of the TADF molecule, respectively.

[0166] Embodiment 2

[0167] This embodiment 2 provides a light-emitting compound M2, the chemical structural formula of which is as follows:

[0168]

[0169] The synthesis route of the light-emitting compound M2 is as follows:

[0170]

[0171] The preparation steps of the light-emitting compound M2 are as follows:

[0172] Compound (5) (24.1 g, 100 mmol) was mixed with compound (6) (o-bromotoluene, 17.8 g, 105 mmol) in 1,2-dichloroethane (420 mL), and aluminum trichloride (33.25 g, 250 mmol) was dissolved in 250 mL of 1,2-dichloroethane to form a solution of aluminum trichloride (in which aluminum trichloride serves as a catalyst) at room temperature. The solution of aluminum trichloride was added to the above reaction system, and the reaction temperature was increased to 70-100°C after the solution of aluminum trichloride was completely added. The reaction was carried out for 12-24 hours. After the reaction was quenched with dilute hydrochloric acid, off-white precipitates were filtered, washed with dilute hydrochloric acid, and dried in vacuum to obtain about 39 g of a crude product. The 39 g of the crude product was mixed with 150 g of pyrophosphoric acid (pyrophosphoric acid is used as a dehydrating agent for the ketone group formed by condensation of carboxyl and aryl groups) in a 500 mL round bottom flask, heated to 80-120°C, and maintained for 6-18 hours. After the reaction was completed, the reaction temperature was lowered to room temperature, 200 g of ice was added to the product system, the suspended light yellow solid was suction filtered, repeatedly washed with an aqueous sodium hydroxide solution, recrystallized with chloroform / toluene, and compound (7) (13.7 g, about 35% yield) was obtained.

[0173] Compound (7) (3.9 g, 10.0 mmol), 9-phenyl-carbazol-3-boronic acid (compound (4), 1.9 g, 6.5 mmol), potassium carbonate (3.0 g, 21.6 mmol), and tetrabutylammonium bromide (80 mg) were placed in a two-necked flask, and toluene (80 mL) and water (20 mL) were added thereto. After purging with nitrogen for 10-15 minutes, Pd(PPh3)4 catalyst (55 mg) was further added to the two-necked flask, and then a Suzuki coupling reaction was performed under nitrogen. After the reaction was carried out at 85°C for 12-18 hours, the reaction system was cooled to room temperature, and then extracted with dichloromethane / water. After column chromatography by spinning off the solvent, compound (8) (3.22 g, 58% yield) was obtained.

[0174] Compound (8) (2.76 g, 5.0 mmol), 1-(diphenylamino)-2-methyl-4-phenylboronic acid (compound (9), 3.75 g, 13 mmol), potassium carbonate (3.0 g, 21.6 mmol), and tetrabutylammonium bromide (80 mg) were placed in a two-necked flask, and ethanol (10 mL) and water (10 mL) were added thereto. After purging with nitrogen for 10-15 minutes, Pd-123 catalyst (7 mg) was further added to the two-necked flask, and then a Suzuki coupling reaction was performed under nitrogen. After the reaction was carried out at 85°C for 4-10 hours, the reaction system was cooled to room temperature, and then extracted with dichloromethane / water. After column chromatography by spinning off the solvent, light-emitting compound M2 (3.38 g, 92% yield) was obtained.

[0175] Elemental tests were performed on the light-emitting compound M1, and the test parameters are shown below:

[0176] 1 H NMR (CDCI3, 500 MHz): δ (ppm) 8.68 (s, 1H), 8.52 (s, 1H), 8.46 (m, 1H), 8.26-8.16 (m, 7H), 7.32-7.29 (m, 7H), 7.18-7.16 (m, 6H), 7.06 (m, 3H), 2.96 (s, 3H), 2.64 (s, 3H), 2.58 (s, 3H); HRMS m / z: 735.2913 [M] + According to the above test parameters, the chemical structural formula of the light-emitting compound M2 is consistent with the above chemical structural formula.

[0177] The light-emitting compound M2 provided in this embodiment 2 is further improved compared with the light-emitting compound M1 provided in embodiment 1, and the specific improvements are as follows: through a simple F-C reaction, the structure of 2,6-dibromoanthraquinone is modified to obtain 2,6-dibromoanthraquinone containing symmetric dimethyl substituents (compound (7)), which solves the problem that the anthraquinone structure cannot be modified in the related art. Moreover, the two different electron donor groups are asymmetrically introduced by two consecutive Suzuki reactions, so that the light-emitting compound M2 has a high PLQY. This is embodied in that the light-emitting compound M2 not only has a high PLQY in the light-emitting layer, but also has a large improvement in PLQY in different solvents. Through testing, the light-emitting compound M2 exhibits an EQE greater than 20% in an OLED device.

[0178] Through research, the reasons why the light-emitting compound M2 has the above beneficial effects include: in the M2 molecule, the methyl-substituted triphenylamine structure can effectively make the M2 molecule have a suitable fluorescent light-emitting wavelength, the phenyl-substituted carbazole structure has a small contribution to the HOMO energy level of the M2 molecule, but can effectively regulate the energy level splitting of the triplet excited state and the singlet excited state of the M1 molecule, so that the energy level difference between the singlet state and the triplet state is smaller, which has the following very beneficial effects on the photophysics of the M2 molecule: 1) the energy level transition probability of the excited state intersystem crossing and the reverse intersystem crossing of the M2 molecule is improved, which effectively improves the delayed fluorescence light-emitting efficiency;

[0179] 2) The triplet-triplet annihilation of M2 molecules is effectively inhibited; 3) The introduction of two methyl groups on the anthraquinone group not only effectively causes the formation of a suitable steric effect between the triphenylamine group and the carbazole group and the anthraquinone group, improving the electron cloud overlap between the electron donor group and the electron acceptor group, but also limits the molecular vibration of the triphenylamine group and the carbazole group in the excited state, inhibiting the energy loss caused by non-radiative transition in the excited state.

[0180] It can be seen that the luminescent compound M2 provided in Example 2 is synthesized by using commercially available and easily available raw materials to synthesize functionalized anthraquinone, and then to synthesize an asymmetric TADF molecule, two different electron donor groups are asymmetrically distributed relative to the electron acceptor group, in order to respectively regulate the above-mentioned HOMO level, triplet excited state and charge transport function of the TADF molecule. The methyl substituent is introduced between the triarylamine donor group and the anthraquinone acceptor group to limit molecular vibration and cause steric hindrance, which greatly improves the luminescent performance of the luminescent compound without affecting the luminescent wavelength.

[0181] Example 3

[0182] This example 3 provides a luminescent compound M3, the chemical structural formula of which is as follows:

[0183]

[0184] The synthesis route of the luminescent compound M3 is as follows:

[0185]

[0186] According to the preparation method of compound (7) shown in Example 2, compound (10) was synthesized with a yield of 42%. According to the preparation method of compound (8) shown in Example 2, compound (11) was synthesized with a yield of 65%. According to the preparation method of compound M2 shown in Example 2, compound M3 was synthesized with a yield of 93%.

[0187] Elemental tests were performed on the luminescent compound M3, and the test parameters are as follows:

[0188] 1H NMR (CDCI3, 500 MHz): δ (ppm) 8.78 (s, 1H), 8.63 (s, 1H), 8.28 (s, 2H), 8.22 (s, 2H), 8.20-8.16 (m, 7H), 7.66 (m, 6H), 7.32-7.29 (m, 5H), 7.18-7.16 (m, 4H), 7.06 (m, 3H), 2.94 (s, 3H); HRMS m / z: 743.2419 [M] +According to the above test parameters, the chemical structural formula of the light-emitting compound M3 is consistent with the above chemical structural formula.

[0189] Example 4

[0190] This Example 4 provides a light-emitting compound M4, the chemical structural formula of which is shown as follows:

[0191]

[0192] The synthesis route of the light-emitting compound M4 is shown as follows:

[0193]

[0194] The synthesis steps of the light-emitting compound M4 are shown as follows:

[0195] Compound M3 (7.43 g, 10.0 mmol), carbazole (4.06 g, 25 mmol), potassium iodide (40 mg), and potassium carbonate (5.44 g, 40 mmol) were mixed uniformly in dimethyl sulfoxide (150 mL), and the reaction was carried out under nitrogen protection at 100-120°C for 6-18 hours. After the reaction was completed, the reaction system was lowered to room temperature, and then the reaction product solution was poured into water for filtration, and the solid was filtered out and recrystallized with ethanol and ethyl acetate to obtain the light-emitting compound M4 (9.13 g, yield 88%).

[0196] Elemental tests were performed on the light-emitting compound M4, and the test parameters are shown as follows:

[0197] 1 H NMR (CDCI3, 500 MHz): δ (ppm) 8.92 (s, 1H), 8.89 (s, 1H), 8.84 (s, 1H), 8.69 (s, 1H), 8.55 (m, 3H), 8.32-8.22 (m, 6H), 8.20-8.16 (m, 7H), 7.78-7.60 (m, 8H), 7.36-7.22 (m, 7H), 7.18-7.10 (m, 5H), 7.09-7.02 (m, 5H), 3.02 (s, 3H); HRMS m / z: 1037.3759 [M] + According to the above test parameters, the chemical structural formula of the light-emitting compound M4 is consistent with the above chemical structural formula.

[0198] Example 5

[0199] This Example 5 provides a light-emitting compound M5, the chemical structural formula of which is shown as follows:

[0200]

[0201] The synthetic route of the luminescent compound M5 is shown as follows:

[0202]

[0203] Compound (13) was synthesized according to the method shown in Example 2 using compound (12) and o-methoxybromobenzene, with a yield of 78%; compound (13) was subjected to boron tribromide demethylation and trifluoromethanesulfonyl chloride protection of phenolic hydroxyl group in sequence to obtain compound (14) with a yield of 85%-90%. The key intermediate (15) was obtained from compound (14) and phenylboronic acid under the action of a palladium catalyst with a yield of 80%-92%. According to the method shown in Example 2, intermediate (15) was used as a raw material to perform Suzuki coupling reaction with compound (4) and compound (9) in sequence to obtain compound M5.

[0204] Elemental tests were performed on the luminescent compound M5, and the test parameters are shown as follows: 1 H NMR (CDCI3, 500 MHz): δ (ppm) 8.84 (s, 1H), 8.81 (s, 1H), 8.68-8.66 (d, 2H), 8.28-8.22 (m, 8H), 7.76-7.62 (m, 8H), 7.26-7.18 (m, 6H), 7.16-7.12 (m, 8H), 7.09-7.04 (m, 6H), 2.96 (s, 3H); HRMS m / z: 859.3231 [M] + According to the above test parameters, the chemical structural formula of the luminescent compound M5 is consistent with the above chemical structural formula.

[0205] Example 6

[0206] This example 6 provides a luminescent compound M6, and the chemical structural formula of the luminescent compound M6 is shown as follows:

[0207]

[0208] The synthetic route of the luminescent compound M6 is shown as follows:

[0209]

[0210] The synthesis method of the luminescent compound M6 is shown as follows: the luminescent compound M2 prepared in Example 2 was used as a raw material, and was reacted with malononitrile in anhydrous solvent under the catalysis of TiCl4 to obtain the luminescent compound M6. Since M6 has poorer solubility than M2, it can obtain high-purity product through simple solvent washing and reprecipitation. The HRMS m / z: 831.3143 [M] was obtained through mass spectrometry test. +This means that the chemical structure of the light-emitting compound M6 conforms to the above chemical structure, and in addition, by using the difference in solubility of the light-emitting compound M6 and the light-emitting compound M2 and the efficient implementation of the above reaction conditions, a light-emitting compound M6 with high purity can be easily and conveniently obtained.

[0211] Application Example 1

[0212] The luminescent properties of the light-emitting compounds provided in Examples 1-5 and the light-emitting compound B1 provided in the comparative example were tested, wherein the chemical structure of the light-emitting compound B1 provided in the comparative example is as follows:

[0213]

[0214] The luminescent properties of the above light-emitting compounds include the following: (1) The photoluminescence spectra of the above light-emitting compounds in toluene solution, tetrahydrofuran solution, and dichloromethane solution were tested, respectively.

[0215] (2) The fluorescence spectra and the fluorescence quantum yield (PLQY) of the above light-emitting compounds in toluene solution, tetrahydrofuran solution, dichloromethane solution, and solid-state thin film were tested, respectively. The raw materials for preparing the above solid-state thin film include 4,4-bis(9-carbazole) biphenyl (CBP) and one of the above light-emitting compounds, and the doping mass concentration of the above light-emitting compounds can be 1%. The preparation method is to co-evaporate CBP and the doped light-emitting compound, so that the mass concentration of CBP in the co-evaporated solid-state thin film is 99%, and the mass concentration of the light-emitting compound is 1%.

[0216] The test results are shown in Tables 1 and 2.

[0217] Table 1

[0218]

[0219] Table 2

[0220]

[0221] The PLQY of the light-emitting compound B1 provided in the comparative example in the solid-state thin film with a doping mass concentration of 1% reached 78%, but as can be seen from Tables 1 and 2, the PLQY of B1 in toluene solution has already decayed to 59% (the toluene solution of the test sample was deoxygenated by nitrogen flow blowing), and almost no fluorescence was detected in tetrahydrofuran, dichloromethane, and solid-state thin film, which is caused by solvent effect and concentration quenching, and is also related to the excited state interaction of the B1 material in polar solvents. It can be seen that the B1 material exhibits triplet-singlet annihilation and triplet-singlet annihilation.

[0222] The luminescent compounds M1-M5 provided by the embodiments 1-5 can be normally detected for fluorescence in toluene solution, tetrahydrofuran solution, dichloromethane solution and solid-state thin film. In particular, for the compound M4, in addition to the triphenylamine group and the N-phenyl-carbazole group, the molecule further has two carbazole groups, the PLQY in toluene solution is up to 92% or more, and the PLQY in the solid-state thin film is up to 35%, which indicates that the introduction of two 9-carbazole substituents to the 3rd and 7th positions of the anthraquinone group respectively makes the luminescent compound M4 obtain a luminescent behavior completely different from the luminescent compound with symmetrically arranged substituents on the anthraquinone.

[0223] In addition, although the luminescent compound provided by the embodiments 1-5 of the present disclosure only contains one triphenylamine group, and even further, the methyl group is introduced to the benzene ring of the triphenylamine group connected to the anthraquinone, it still makes the luminescent compound obtain a maximum emission wavelength close to that of B1 (only a few nanometers different), which is quite unexpected and important, and further supports the following conclusion: in the molecular design of the luminescent compound, the use of one strong donor unit can well regulate the molecular luminescent wavelength of the luminescent compound, and the use of more carbazole groups can regulate the luminescent intensity, triplet energy level splitting, singlet-triplet energy level difference of the luminescent compound and inhibit the efficiency roll-off in the OLED device.

[0224] Test Example 2

[0225] The present test example 2 provides an OLED device, which comprises, from bottom to top, an anode 1, a hole injection layer 2, a hole transport layer 3, a hole transport / electron blocking layer 4, a luminescent layer 5, an electron transport layer 6, an electron injection layer 7 and a cathode 8. The anode 1 is ITO conductive glass, the hole injection layer 2 is HAT(CN)6, the hole transport layer 3 is TAPC, the hole transport / electron blocking layer 4 is TCTA, the electron transport layer 6 is TmPyPB, the electron injection layer 7 is 8-hydroxyquinoline-lithium, and the cathode 8 is metal Al.

[0226] The preparation raw materials of the luminescent layer 5 include a host luminescent material and a luminescent compound, wherein the host luminescent material is 4,4-bis(9-carbazole)diphenyl, abbreviated as CBP, the luminescent compound is M1 provided by the embodiments, and the mass ratio of the host luminescent material to the luminescent compound is 100:5.

[0227] The OLED device is tested, and the test results show that the maximum EQE of the OLED is 18.5%, and the electroluminescent spectrum peak is 612 nm. Compared with the luminescent compound B1 (under the same conditions, the maximum EQE thereof is about 12%-13%), the luminescent compound provided by the embodiments of the present disclosure realizes an increase of 50% in the maximum external quantum efficiency through the molecular design, so that the luminescent compound provided by the embodiments of the present disclosure has great application potential in the field of OLED devices.

[0228] The above merely aims to facilitate the understanding of the technical solutions of the present disclosure by those skilled in the art, and is not used to limit the present disclosure. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A luminescent compound, characterized in that, The chemical structural formula of the light-emitting compound is shown as follows: wherein X 1 and X 2 are each independently selected from oxygen or dicyanomethylidene; R 1 , R 2 , R 4 , R 5 , R 6 , R 8 is selected from D, F, CI, CN, CH3, phenyl or carbazolyl; R 3 and R 7 are two different electron donor groups, one of which is any of the following groups: The other of the two different electron donor groups is any of the following groups:

2. A light-emitting layer raw material characterized by comprising The light-emitting layer raw material comprises the light-emitting compound of claim 1.

3. The light-emitting layer material according to claim 2, wherein The light-emitting layer raw material further comprises a host light-emitting material, the host light-emitting material comprising at least one of the following groups: triphenylene, carbazole, dithiophene, difuran, diselenophene, aza-triphenylene, aza-carbazole, aza-dithiophene, aza-difuran, aza-diselenophene.

4. The light-emitting layer material according to claim 2 or 3, characterized in that The light-emitting layer raw material further comprises a fluorescent material.

5. An organic light emitting device, characterized by, The organic light-emitting device comprises a light-emitting layer prepared from the light-emitting layer raw material of any one of claims 2-4.

6. A method for producing a luminescent compound, characterized by, The light-emitting compound is as claimed in claim 1; The preparation method of the light-emitting compound comprises: providing at least two different electron donor compounds, and respectively performing boron ester or boric acid treatment on the at least two different electron donor compounds to obtain at least two electron donor compounds in the form of boric acid or borate; The at least two electron donor compounds in the form of boric acid or borate are sequentially introduced into an anthraquinone compound through a Suzuki coupling reaction to obtain the light-emitting compound.

7. The method for preparing the luminescent compound according to claim 6, characterized in that, The anthraquinone compound comprises an anthraquinone group and two halogen substituents, the two halogen substituents being respectively connected to two symmetrical positions in positions 1-8 of the anthraquinone group.

8. The method for preparing the luminescent compound according to claim 6, characterized in that, The anthraquinone compound is prepared by the following method: The derivative of benzene and the derivative of phthalic anhydride are subjected to a Friedel-Crafts reaction to obtain the anthraquinone compound; The chemical structural formula of the derivative of benzene is shown as follows: B1, B2, B3, and B4 are each independently selected from hydrogen, D, F, C1-C20 straight-chain or branched alkyl; The chemical structural formula of the derivative of phthalic anhydride is shown as follows: A1, A2, A3, and A4 are each independently selected from methyl, fluorine, chlorine, or bromine.

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