A heterocyclic iridium metal phosphorescent dopant material, and a preparation method and application thereof

Abstract

The present application relates to the field of organic synthesis and organic optoelectronic materials, and discloses a heterocyclic iridium metal phosphorescent doping material, a preparation method and application thereof.The structure of the heterocyclic iridium metal phosphorescent doping material is shown in formula I.The compound provided by the present application can be used as a light-emitting layer doping material, and an iridium metal phosphorescent organic light-emitting material is prepared by introducing a benzene silicon / germanium heterocycle and a naphthalene ring on a pyridine ring, and then reacting with an iridium metal and a diketone monomer.The naphthalene ring in the material widens the conjugated skeleton, and the silicon / germanium heterocycle optimizes the energy level matching, and due to the rigidity of the benzene ring and the stability of the benzene ring and silicon, energy level regulation and carrier transport optimization can be achieved, thereby reducing the driving voltage, improving the luminous efficiency and prolonging the service life.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of organic synthesis and organic optoelectronic materials, in particular to a heterocyclic iridium metal phosphorescent dopant material and a preparation method and application thereof. BACKGROUND

[0002] Since the first report of high efficiency organic electroluminescent devices in 1987, OLED technology has undergone more than thirty years of rapid development and has become the most promising flat panel display technology after liquid crystal display (LCD). OLED display technology has many advantages, such as relatively simple preparation process, low turn-on voltage, high brightness, high efficiency, fast response speed, active light-emitting, wide viewing angle, no radiation, easy realization of large plane and flexible display, and potential low cost advantage. These characteristics make OLED increasingly widely used in the fields of smart phones, televisions, wearable devices, etc.

[0003] The material of the OLED light-emitting part is mainly organic fluorescent material, which can be roughly divided into red, blue and green light. In recent research, it is found that unlike traditional phosphorescent materials that rely only on singlet excitons, organic phosphorescent materials can increase internal quantum efficiency to 100% by adding heavy metals, which promotes stable spin-orbital coupling and promotes the mixing of singlet and triplet states. Therefore, in recent years, people have devoted to the research of heavy metal coordination organic phosphorescent materials, especially the research of metal iridium complex fluorescent materials.

[0004] In continuous research, it is found that compared with blue and green light materials, red light materials have problems such as serious efficiency roll-off, insufficient color purity and poor stability. Therefore, how to obtain high-performance red light materials is crucial for the development of organic electroluminescent devices. SUMMARY

[0005] Therefore, the purpose of the present application is to provide a heterocyclic iridium metal phosphorescent dopant material and a preparation method and application thereof. By introducing a benzene silicon / germanium heterocycle and a naphthalene ring on the pyridine ring, and then reacting with iridium metal and diketone monomers, an iridium metal phosphorescent organic light-emitting material is prepared. Since the naphthalene ring in the material widens the conjugated backbone, the silicon / germanium heterocycle optimizes the energy level matching, and at the same time, due to the rigidity of the benzene ring and the stability of the benzene ring and silicon, energy level regulation and carrier transport optimization can be achieved, thereby reducing the driving voltage, improving the luminous efficiency and prolonging the service life.

[0006] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0007] The first purpose of the present application is to provide a heterocyclic iridium metal phosphorescent dopant material, which has the structural general formula of Ir(L a )2(L b )1; wherein La represents a first ligand coordinated to the metal iridium, L b represents a second ligand coordinated to the metal iridium; "2" represents L a the number of ligands is two, "1" represents L b the number of ligands is one.

[0008] The structural general formula is as follows:

[0009] ;

[0010] Among them, the ring H can be selected from the following structures:

[0011] ,

[0012] that is, L a The ligand can have the following structure:

[0013] ;

[0014] The ligand L a X in the ligand L

[0015] The ligand L a R1~ R4 in the ligand L 40 alkyl, substituted or unsubstituted C6-C 40 aryl, substituted or unsubstituted C4-C 40 heteroaryl, substituted or unsubstituted C3-C 40 cycloalkyl, substituted or unsubstituted C1-C 40 alkoxy, substituted or unsubstituted C2-C 40 alkenyl and alkynyl, substituted or unsubstituted C3-C 40 heterocyclyl, substituted or unsubstituted C5-C 40 spirocyclyl, substituted or unsubstituted C1-C 40 silyl, substituted or unsubstituted C1-C 40 germyl, and combinations thereof, and adjacent substituents can be fused into a ring; the heteroatom can be one or a combination of O, S, N, P, B, Si and Ge;

[0016] All hydrogen atoms in the substituents of R1~ R4 can be deuterated;

[0017] R1~R4 positions are the same or different; the positions of R1~R4 substituents are any positions of the benzene ring; the number of R1 substituents is 2, the number of R3 substituents is 1, and the number of R2 and R4 substituents is 0~4;

[0018] The ligand L b has the following structural formula:

[0019] ;

[0020] wherein R a ~R c are each independently selected from the group consisting of hydrogen, deuterium atom, halogen, cyano, substituted or unsubstituted C1-C 20 alkyl, substituted or unsubstituted C3-C 20 cycloalkyl;

[0021] The substituents of R a ~R b may all be replaced by deuterium.

[0022] Further,

[0023] Formula I has the following structural formula:

[0024] ;

[0025] wherein,

[0026] R1~ R4 are each independently selected from the group consisting of substituted or unsubstituted C1-C 10 alkyl, substituted or unsubstituted C6-C 20 aryl, substituted or unsubstituted C4-C 12 heteroaryl, substituted or unsubstituted C3-C7 cycloalkyl, substituted or unsubstituted C1-C 10 alkoxy, substituted or unsubstituted C2-C 10 alkenyl and alkynyl, substituted or unsubstituted C3-C 10 heterocyclyl, substituted or unsubstituted C3-C 10 silyl, substituted or unsubstituted C3-C 10 germyl, and combinations thereof, and adjacent substituents can be fused to form the following groups: substituted or unsubstituted cyclohexyl, substituted or unsubstituted cyclohexenyl, substituted or unsubstituted phenyl, substituted or unsubstituted benzofuranyl, substituted or unsubstituted benzothiophenyl, substituted or unsubstituted benzocyclopentyl, substituted or unsubstituted benzocyclohexanone, substituted or unsubstituted benzocyclohexane.

[0027] Further,

[0028] R1~ R4each independently is selected from hydrogen, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, neopentyl and n-hexyl; phenyl, biphenyl, naphthyl, fluorenyl; pyridyl, furanyl, thienyl, pyrimidyl, pyrazinyl, benzofuranyl, benzothienyl, indolyl, quinoline and isoquinoline, carbazolyl, dibenzofuranyl, dibenzothienyl, benzimidazole, benzothiazole; cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane; methoxy, ethoxy, propoxy, butoxy, pentoxy; ethenyl, propenyl, 1-butenyl, 1-pentenyl, isopropenyl, neopentenyl, trimethylethenyl, ethynyl, propynyl, 1-butynyl, 1-pentynyl, 1-hexynyl, isobutynyl, neopentynyl, tert-butynyl; oxiranyl, oxetanyl, dioxolanyl, dioxanyl, pyrazole, imidazole, oxazole, thiazole, tetrahydrothiophene, pyrazine, pyridazine; trimethylsilyl, triethylsilyl, methyldiethylsilyl, ethyldimethylsilyl, tripropylsilyl, tributylsilyl, triisopropylsilyl, methyldiisopropylsilyl, dimethylisopropylsilyl, tri-tert-butylsilyl, triisobutylsilyl, dimethyl-tert-butylsilyl, methyldi-tert-butylsilyl, preferably trimethylsilyl; trimethylgermyl, triethylgermyl, methyldiethylgermyl, ethyldimethylgermyl, tripropylgermyl, tributylgermyl, triisopropylgermyl, methyldiisopropylgermyl, dimethylisopropylgermyl, tri-tert-butylgermyl, triisobutylgermyl, dimethyl-tert-butylgermyl, methyldi-tert-butylgermyl, most preferably trimethylgermyl.

[0029] In the technical solution of the present application, the ligand L b may be selected from the following structures:

[0030] .

[0031] wherein the substituent in the "substituted or unsubstituted" refers to a substituent, i.e. the substituent can be alkyl, cycloalkyl, heteroalkyl, heterocyclyl, aralkyl, alkoxy, aryloxy, alkenyl, alkynyl, aryl, heteroaryl, alkylsilyl, arylsilyl, alkylgermyl, arylgermyl, amino, acyl, carbonyl, carboxylic acid, ester, cyano, sulfinyl, sulfonyl and phosphine, and halogen. Preferably, the substituent is deuterium, methyl, ethyl, propyl, isopropyl, tert-butyl, 2-methylpropyl, 2,2-dimethylpropyl, phenyl, naphthyl, fluorenyl, bi-phenyl, tri-phenyl, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, ethenyl, ethynyl, oxiranyl, oxetanyl, tetrahydrofuranyl, benzofuranyl, benzothienyl, carbazolyl, cyano, sulfonic acid, halogen, trimethylsilyl and trimethylgermyl.

[0032] The specific structure of the heterocyclic iridium metal phosphorescent doping material in the technical scheme of the present application is selected from any one of the following, but is not limited to this:

[0033] .

[0034] The second object of the present application is to provide a preparation method of the heterocyclic iridium metal phosphorescent doping material as described above, and the synthesis general formula is as follows:

[0035] ;

[0036] Y is selected from bromine or chlorine.

[0037] The synthesis steps are as follows:

[0038] (1) A three-necked flask is added with toluene, anhydrous ethanol and water, then reactant 1 and reactant 2 are added, nitrogen is replaced, then Pd (pph3) 4 and anhydrous potassium carbonate K2CO3 are added, nitrogen is replaced, then the reaction is carried out at 100℃ for 24h, after the reaction is completed, the intermediate 1 is obtained by liquid separation, rotary evaporation and column chromatography.

[0039] (2) A three-necked flask is added with toluene, then the intermediate 1, tetrabutylammonium bromide TBAB, sodium tert-butoxide NaOt-Bu, tri-tert-butyl phosphorus Pt-Bu3 are added, then nitrogen is replaced, then Pd (pph3) 4 is added, the reaction is carried out at 120℃ for 16h, then L is obtained by rotary evaporation and column chromatography. aLigand intermediate 2.

[0040] (3) In a three-necked flask, add ethylene glycol ether and water, put ligand intermediate 2 into the reaction system, replace nitrogen, then add iridium trichloride, and react under the protection of nitrogen at 120 DEG C for 48 h; after the reaction is completed, cool to room temperature, then filter by suction, rinse with anhydrous ethanol and petroleum ether in sequence, and finally dry to obtain intermediate 3. a Put ligand intermediate 2 into the reaction system, replace nitrogen, then add iridium trichloride, and react under the protection of nitrogen at 120 DEG C for 48 h; after the reaction is completed, cool to room temperature, then filter by suction, rinse with anhydrous ethanol and petroleum ether in sequence, and finally dry to obtain intermediate 3.

[0041] (4) In a three-necked flask, add ethylene glycol ether and water, put ligand intermediate 2 into the reaction system, replace nitrogen, then add iridium trichloride, and react under the protection of nitrogen at 120 DEG C for 48 h; after the reaction is completed, cool to room temperature, then filter by suction, rinse with anhydrous ethanol and petroleum ether in sequence, and finally dry to obtain intermediate 3. b Put ligand intermediate 2 into the reaction system, replace nitrogen, then add iridium trichloride, and react under the protection of nitrogen at 120 DEG C for 48 h; after the reaction is completed, cool to room temperature, then filter by suction, rinse with anhydrous ethanol and petroleum ether in sequence, and finally dry to obtain intermediate 3.

[0042] A third object of the present application is to provide an organic electroluminescent device, which comprises an anode and a cathode and an organic functional layer arranged between the anode and the cathode, the organic functional layer comprising a hole transport layer, a light-emitting layer and an electron transport layer; the light-emitting layer comprising a host material and a dopant material, the dopant material comprising the heterocyclic iridium metal phosphorescent dopant material as described above.

[0043] Optionally, the anode material can be divided into two categories, the first category being a traditional anode material, such as indium tin oxide (ITO), indium zinc oxide (IZO), gold (Au), silver (Ag) and the like, and the second category being a new anode material, such as poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid (PEDOT:PSS), polyaniline (PANI), graphene composite electrode and the like.

[0044] Optionally, the hole transport layer material can be a phthalocyanine derivative, a conductive polymer or a polymer containing a conductive dopant, such as polyphenylenevinylene, polyaniline / dodecylbenzenesulfonic acid, poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate), polyaniline / camphor sulfonic acid, polyaniline / poly(4-styrenesulfonate), an aromatic amine derivative and the like.

[0045] Further, the hole transport layer can also be provided with a hole injection layer and an electron blocking layer, wherein the hole injection layer is arranged between the anode and the hole transport layer, and the material used can be improved PEDOT:PSS, formula A and formula B, but is not limited thereto.

[0046] ;

[0047] Optionally, the light-emitting layer generally comprises a host material and a dopant material, the host material provides a carrier transport channel, and the dopant material improves the light-emitting efficiency, and generally is a red, green or blue phosphor material, such as the heterocyclic iridium metal phosphor dopant material of the structure shown in Formula I in the present application.

[0048] Optionally, the electron transport layer is generally a single-layer structure, and the material of the electron transport layer can be a single compound or a combination of multiple compounds, such as Alq3 (tris (8-hydroxyquinoline) aluminum), Znq (tris (8-hydroxyquinoline) zinc), Bebq2 (bis (10-hydroxybenzo [h] quinoline) beryllium, TPBi (1, 3, 5-tris (1-phenyl-1H-benzimidazole-2-yl) benzene), Bphen (4, 7-diphenyl-1, 10-phenanthroline), TAZ (1, 2, 4-triazole derivative) or polyfluorene derivative and polyparaphenylenevinylene.

[0049] Further, the electron transport layer can also be added with an electron injection layer and a hole blocking layer. The electron injection layer is located between the electron transport layer and the cathode, and the material of the electron injection layer can be one or more of LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li and Ca.

[0050] Optionally, the cathode material comprises magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag) and the like metal or alloy and any combination thereof.

[0051] Compared with the prior art, the present application provides a heterocyclic iridium metal phosphor dopant material, a preparation method and application thereof, and has the following excellent effects:

[0052] The present application provides a heterocyclic iridium metal phosphor dopant material containing silicon or germanium elements, which is connected with silicon / germanium elements in the structure and forms a six-membered ring structure with naphthalene. On the one hand, the introduction of the silicon or germanium six-membered ring can adjust the HOMO and LUMO energy levels, and the sigma-pi conjugation effect of the silicon / germanium atoms can enhance the carrier mobility and reduce the charge recombination loss, thereby improving the light-emitting efficiency. On the other hand, the rigidity of the silicon / germanium ring and the benzene ring, as well as the good chemical passivity of silicon / germanium and the thermal stability of naphthalene, increase the service life of the device. BRIEF DESCRIPTION OF DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort on the basis of the provided drawings.

[0054] Figure 1 The nuclear magnetic resonance hydrogen spectrum of the heterocyclic iridium metal phosphorescent dopant material I-10 in the embodiment 1 of the present application. DETAILED DESCRIPTION

[0055] The technical solutions of the present application will be described clearly and completely below in combination with the embodiments of the present application and the related drawings. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, all the other embodiments obtained by the ordinary skilled in the art without creative labor fall within the scope of protection of the present application.

[0056] The present application specifically discloses a heterocyclic iridium metal phosphorescent dopant material, a preparation method and application thereof.

[0057] The technical solutions of the present application will be described clearly and completely below in combination with the embodiments of the present application and the related drawings. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, all the other embodiments obtained by the ordinary skilled in the art without creative labor fall within the scope of protection of the present application.

[0058] Embodiment 1

[0059] The present embodiment provides a phosphorescent dopant material I-10 containing silicon element, i.e. compound numbered I-10, and the specific synthesis steps are as follows:

[0060] 1. Synthesis of reactant 1-1

[0061]

[0062] In a three-necked flask, 45 times of 4-(dimethylsilyl)benzonitrile was added isopropanol, and after replacing nitrogen twice, 2-bromo-3-iodopyridin-4-amine (1.15 eq) (CAS: 1300750-77-9), 4-(dimethylsilyl)benzonitrile (1 eq) (CAS: 129409-68-3), cuprous iodide (0.008 eq) and isopropanol (3 eq) were added, and after replacing nitrogen twice, the reaction was carried out at 20℃ for 0.5h; then anhydrous potassium carbonate was added, and after replacing nitrogen twice, the reaction was carried out at 100℃ for 20h under reflux; after the reaction was completed, the solvent was removed, diluted with 500 mL of acetic acid, and then tert-butyl nitrite (2.2 eq) was added, and stirred at room temperature overnight; after the reaction was completed, the reaction liquid was poured into water, and the generated solid was column-purified to obtain the reactant 1-1 (yield: 42%).

[0063] MS (ESI, m / Z): [M+H]+: 315.83.

[0064] 2. Synthesis of reactant 2-1

[0065]

[0066] In a three-necked flask, 25 times 7-tert-butyl-naphthalene-2-boronic acid mass of N, N-dimethylformamide was added, and after replacing nitrogen twice, 7-tert-butyl-naphthalene-2-boronic acid (1 eq) (CAS: 2869040-16-2), N-bromosuccinimide (1.2 eq) and azobisisobutyronitrile (0.08 eq) were added, and after replacing nitrogen twice again, the reaction was carried out for 24 h at 25°C in the dark; after the reaction was completed, pure water was added for quenching, and ethyl acetate was used for liquid separation, and then rotary evaporation, column chromatography purification were carried out to obtain the reactant 2-1 (yield: 53%).

[0067] MS (ESI, m / Z): [M+H]+: 307.62.

[0068] 3. Synthesis of ligand L a -10

[0069]

[0070] In a three-necked flask, 20 times the mass of reactant 1-1 of toluene, 10 times of anhydrous ethanol and water were added, and then reactant 1-1 (1 eq) and reactant 2-1 (2 eq) were added, and after replacing nitrogen twice, Pd (pph3) 4 (0.02 eq) and anhydrous potassium carbonate (K2CO3) (3 eq) were added, and then nitrogen was replaced twice, and the reaction was carried out for 24 h at 100°C, and after the reaction was completed, liquid separation, rotary evaporation and column chromatography were carried out to obtain the intermediate 1-1 (yield: 76%).

[0071] In a three-necked flask, 20 times the mass of intermediate 1-1 of toluene was added, and then intermediate 1-1 (1 eq) was added, and after replacing nitrogen twice, TBAB (0.02 eq), NaOt-Bu (2.5 eq), Pt-Bu3 (0.08 eq) and Pd (pph3) 4 (0.02 eq) were added, and then nitrogen was replaced twice; the reaction was carried out for 16 h at 120°C, and then L a ligand-10 (yield: 66%).

[0072] MS (ESI, m / Z): [M+H]+: 416.28.

[0073] 4. Synthesis of formula I-10

[0074]

[0075] L aLigand-10 (2.5 eq) and IrCl3·3H2O (1 eq) were placed in a three-necked flask, then 15 times L of ethylene glycol ethyl ether was added, and after being replaced with nitrogen twice, the reaction was refluxed at 120°C for 48 hours, and then cooled to room temperature. The precipitate was suction filtered, washed with anhydrous ethanol and petroleum ether in turn, and dried to obtain the bridged ligand intermediate 2-1 (yield: 92%). a Ligand-10 (2.5 eq) and IrCl3·3H2O (1 eq) were placed in a three-necked flask, then 15 times L of ethylene glycol ethyl ether was added, and after being replaced with nitrogen twice, the reaction was refluxed at 120°C for 48 hours, and then cooled to room temperature. The precipitate was suction filtered, washed with anhydrous ethanol and petroleum ether in turn, and dried to obtain the bridged ligand intermediate 2-1 (yield: 92%).

[0076] Ligand-10 (2.5 eq) and IrCl3·3H2O (1 eq) were placed in a three-necked flask, then 15 times L of ethylene glycol ethyl ether was added, and after being replaced with nitrogen twice, the reaction was refluxed at 120°C for 48 hours, and then cooled to room temperature. The precipitate was suction filtered, washed with anhydrous ethanol and petroleum ether in turn, and dried to obtain the bridged ligand intermediate 2-1 (yield: 92%). b Ligand-10 (2.5 eq) and IrCl3·3H2O (1 eq) were placed in a three-necked flask, then 15 times L of ethylene glycol ethyl ether was added, and after being replaced with nitrogen twice, the reaction was refluxed at 120°C for 48 hours, and then cooled to room temperature. The precipitate was suction filtered, washed with anhydrous ethanol and petroleum ether in turn, and dried to obtain the bridged ligand intermediate 2-1 (yield: 92%).

[0077] MS (ESI, m / Z): [M+H]+: 1108.15.

[0078] The NMR data of formula I-10 are shown in the following table. Figure 1

[0079] The preparation methods of other material compounds are the same as above, which will not be described one by one.

[0080] Device Example 1

[0081] The material compound of formula I-10 was prepared into an organic electroluminescent device, and the preparation method was as follows:

[0082] 1. The ITO patterned glass substrate was cut into a size of 50mm x 50mm x 0.5mm, washed with detergent for three times, each for 5 minutes, and then ultrasonically treated with isopropanol and acetone in turn for 10 minutes, dried with nitrogen, and finally exposed to ultraviolet light and ozone for 30 minutes.

[0083] 2. The obtained glass substrate was loaded onto a vacuum deposition device, and formula A was first evaporated on the anode as a hole injection layer, with a thickness of 100 angstroms; then formula C was evaporated as a first hole layer, with a thickness of 600 angstroms; then formula D was evaporated as an electron blocking layer, with a film thickness of 50 nm;

[0084]

[0085] ​3. The host material 4,4'-bis(N-carbazolyl)1,1'-biphenyl (CBP) and the dopant material of formula I-10 are prepared into a light-emitting layer in a mass ratio of 95:5, and the evaporation thickness is 400 angstroms; then a TPBI (formula E) electron transport layer with an evaporation thickness of 400 angstroms is evaporated on the light-emitting layer, an electron injection layer of LiF with an evaporation thickness of 10 angstroms is evaporated on the electron transport layer, and finally a cathode material Al with an evaporation thickness of 1500 angstroms is evaporated on the electron injection layer, thereby obtaining a red light-emitting organic electroluminescent device.

[0086] Device Example 2-Device Example 50

[0087] Referring to Device Example 1, the compound of formula I-10 shown in the dopant material in the organic electroluminescent device is replaced by compounds of formula I-1, I-2, I-8, I-12, I-16, I-20, I-30, I-31, I-36, I-40, I-45, I-53, I-59, I-66, I-70, I-82, I-90, I-99, I-106, I-109, I-118, I-133, I-142, I-145, I-184, I-195, I-201, I-215, I-241, I-243, I-244, I-251, I-258, I-312, I-319, I-346, I-362, I-387, I-420, I-436, I-474, I-491, I-532, I-552, I-570, I-576, I-590, I-598, I-607, respectively, and each is prepared into an organic electroluminescent device, which is denoted as Device Example 2-Device Example 50, and the details are shown in Table 1.

[0088] Comparative Example 1-Comparative Example 6

[0089] The organic electroluminescent devices are prepared by the same method as in Device Example 1, the dopant material of formula I-10 in the light-emitting layer is replaced by compound 1, compound 2, compound 3, compound 4, compound 5, and compound 6, respectively, and each is prepared into an organic electroluminescent device, which is denoted as Comparative Example 1-Comparative Example 6, and the structures of the compounds are shown as follows:

[0090]

[0091] In order to further illustrate the luminescent performance of the heterocyclic iridium metal phosphorescent dopant material prepared in the present application, the luminescent properties of the organic electroluminescent devices prepared in Device Example 1-Device Example 50 and the devices obtained in Comparative Example 1-Comparative Example 6 are tested, and the measurement is performed by using a KEITHLEY 2400 type source measurement unit and a CS-2000 spectroradiometric luminance meter to evaluate the driving voltage, the luminescent efficiency, and the lifetime, and the results are shown in Table 1.

[0092] Table 1 Luminescence detection data of organic electroluminescent devices (test results are normalized to Comparative Example 1)

[0093]

[0094] As can be seen from Table 1, when the luminous brightness is all 8000, the luminous efficiency and the service life of the device of Example 1-Example 50 are increased, and the driving voltage is reduced, compared with Comparative Example 1-Comparative Example 6. The reason can be that the interaction of the benzene ring, the six-membered heterocycle formed by the silicon / germanium element, and the naphthalene ring in the structure causes the efficiency, the service life to be increased, and the driving voltage to be reduced.

[0095] Firstly, the benzene ring can provide a stable electron transport channel, the silicon / germanium heterocycle has a deep LUMO energy level, reduces the injection barrier, and at the same time, the introduction of silicon / germanium can reduce the LUMO energy level, improve the electron affinity, and improve the injection balance of the carrier, and the double-benzene fused structure of the naphthalene ring expands the conjugated system, enhances the π-π stacking between molecules, and optimizes the carrier transport. At the same time, the silicon heterocycle can reduce the singlet-triplet energy gap, improve the utilization rate of excitons, and the naphthalene ring can enhance the radiation transition probability. Therefore, the interaction of the three promotes the reduction of the driving voltage and the increase of the luminous efficiency.

[0096] Secondly, on the one hand, the high resonance energy of the benzene ring makes it resistant to oxidation, difficult to open ring, and inhibits chemical degradation; on the other hand, the silicon / germanium heterocycle forms a silicon-carbon bond and a germanium-carbon bond with relatively high bond energy, and the naphthalene ring substituted by a substituent group can balance the activity and enhance the stability, and the interaction of the three makes the service life be prolonged.

[0097] Therefore, the organic electroluminescent device prepared by using the compound provided by the present application as a light-emitting layer doping material has a relatively low driving voltage, a better luminous efficiency, and a more durable service life.

[0098] It will be apparent to those skilled in the art that the present application can have many modifications and variations without departing from the spirit and scope of the present application. Therefore, it is intended to cover the modifications and variations of the present application provided in the scope of the appended claims and their equivalents.

[0099] The foregoing description of the disclosed embodiments enables a person skilled in the art to make or use the application. Modifications of these embodiments will occur to persons of skill in the art, and that the appended claims are intended to cover all such modifications that do not depart from the true spirit and scope of the application. Therefore, the application is not limited to the embodiments shown but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A heterocyclic iridium metal phosphorescent dopant material, characterized by, The heterocyclic iridium metal phosphorescent dopant material has a general structural formula of Ir(L a )2(L b )1, as follows: ； L a The ligand is of the following structure: the ligand L a X in the formula (1) is selected from Si or Ge; R1~ R4in said ligand L a each independently selected from the group consisting of hydrogen, deuterium atom, halogen, hydroxyl, cyano, nitro, amino, thiol, substituted or unsubstituted C1-C 10 alkyl, substituted or unsubstituted C6-C 20 aryl, substituted or unsubstituted C4-C 12 heteroaryl, substituted or unsubstituted C3-C7cycloalkyl, substituted or unsubstituted C1-C 10 alkoxy, substituted or unsubstituted C2-C 10 alkenyl and alkynyl, substituted or unsubstituted C3-C 10 heterocyclyl, substituted or unsubstituted C3-C 10 silyl, substituted or unsubstituted C3-C 10 germyl, and adjacent substituents can be fused to form substituted or unsubstituted cyclohexyl, substituted or unsubstituted cyclohexenyl, substituted or unsubstituted phenyl, substituted or unsubstituted benzofuranyl, substituted or unsubstituted benzothiophenyl, substituted or unsubstituted benzocyclopentyl, substituted or unsubstituted benzocyclohexyl, substituted or unsubstituted benzocyclohexyl; heteroatom is a combination of one or more of O, S, N, P, B, Si and Ge; The substituents in the positions of R1~R4 are the same or different; the positions of the substituents of R1~R4 are any positions of the benzene ring; the number of R1 substituents is 2, the number of R3 substituents is 1, and the number of R2 and R4 substituents is 0~4; The ligand L b The structural formula of the ligand L is shown below: ； wherein R a ~R c each independently is selected from hydrogen, a deuterium atom, a halogen, a cyano group, a substituted or unsubstituted C1-C 20 alkyl group, a substituted or unsubstituted C3-C 20 cycloalkyl group; The substituent in the "substituted or unsubstituted" refers to a substituent, i.e., the substituent is deuterium, methyl, ethyl, propyl, isopropyl, tert-butyl, 2-methylpropyl, 2,2-dimethylpropyl, phenyl, naphthyl, fluorenyl, biphenyl, terphenyl, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, vinyl, acetylenyl, oxolane, oxane, tetrahydrofuran, benzofuran, benzothiophene, carbazole, cyano, sulfonic acid, halogen, trimethylsilyl, and trimethylgermyl.

2. The heterocyclic iridium metal phosphorescent dopant material of claim 1, wherein, The atoms in the group can be substituted by deuterium.

3. The heterocyclic iridium metal phosphorescent doped material according to claim 1, characterized in that, R1~ R4 are each independently selected from hydrogen, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, neopentyl, and n-hexyl; phenyl, biphenyl, naphthyl, fluorenyl; pyridyl, furanyl, thiophenyl, pyrimidinyl, pyrazinyl, benzofuranyl, benzothiophenyl, indolyl, quinoline and isoquinoline, carbazolyl, dibenzofuranyl, dibenzothiophenyl, benzimidazole, benzothiazole; cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane; methoxy, ethoxy, propoxy, butoxy, pentoxy; vinyl, propenyl, 1-butenyl, 1-pentenyl, isopropenyl, neopentenyl, trimethylethenyl, acetylenyl, propynyl, 1-butynyl, 1-pentynyl, 1-hexynyl, isobutynyl, neopentynyl, tert-butynyl; oxiranyl, oxetanyl, dioxolanyl, dioxanyl, pyrazole, imidazole, oxazole, thiazole, tetrahydrothiophene, pyrazine, pyridazine; trimethylsilyl, triethylsilyl, methyldiethylsilyl, ethyldimethylsilyl, tripropylsilyl, tributylsilyl, triisopropylsilyl, methyldiisopropylsilyl, dimethylisopropylsilyl, tri-tert-butylsilyl, triisobutylsilyl, dimethyl-tert-butylsilyl, methyl-di-tert-butylsilyl.

4. The heterocyclic iridium metal phosphorescent doped material according to claim 1, characterized in that, The ligand L b is selected from the following structures: 。 5. A heterocyclic iridium metal phosphorescent dopant material, characterized by, The specific structure of the heterocyclic iridium metal phosphorescent dopant material is selected from any one of the following: 。 6. A method for preparing the heterocyclic iridium metal phosphorescent dopant material according to claim 1, characterized by, The method operates as follows: 1) Add toluene, anhydrous ethanol and water in a three-necked flask, then add reactant 1 and reactant 2, replace nitrogen, then add tetra (triphenylphosphine) palladium Pd (pph3) 4 and anhydrous potassium carbonate K2CO3, then replace nitrogen, react at 100℃ for 24h, after the reaction is completed, separate the liquid, spin evaporation, and column chromatography to obtain intermediate 1; 2) In a three necked flask, toluene was added, followed by intermediate 1, tetrabutyl ammonium bromide TBAB, sodium tert-butoxide NaOt-Bu, tri-tert-butyl phosphine Pt-Bu3, followed by Pd(pph3)4, after nitrogen replacement, reaction at 120 °C for 16 h, followed by spin dry, column chromatography to give L a Ligand intermediate 2; 3) In a three-necked flask, add ethylene glycol ether and water, and then add L a The ligand intermediate 2 is put into the reaction system, and nitrogen is replaced. Then, iridium trichloride is added, and the reaction is carried out at 120°C under nitrogen protection for 48h. After the reaction is completed, it is cooled to room temperature, and then filtered by suction, washed with anhydrous ethanol and petroleum ether in sequence, and finally dried to obtain the intermediate 3. 4) In a three-necked flask, add ethylene glycol ether, put intermediate 3 into the reaction system, replace nitrogen, then add ligand L b , under nitrogen protection, reflux at 120°C for 48h; after the reaction is completed, cool to room temperature, then filter the precipitate, rinse with anhydrous ethanol and dry to obtain a compound with the structure shown in formula I; The specific synthesis route is as follows: ； Y is selected from bromine or chlorine.

7. Use of a heterocyclic iridium metal phosphorescent dopant material, characterized in that, The heterocyclic iridium metal phosphorescent dopant material according to any one of claims 1-5 is applied to an organic electroluminescent device.

8. Use according to claim 7, characterized in that, The organic electroluminescent device comprises an organic layer; the organic layer comprises the heterocyclic iridium metal phosphorescent dopant material according to any one of claims 1-5.

9. Use according to claim 8, characterized in that, The heterocyclic iridium metal phosphorescent dopant material is used as a dopant material in a light-emitting layer.

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