A divalent platinum complex and its preparation method and use

Abstract

The present invention relates to the technical field of electronic materials, and in particular to a divalent platinum complex and a preparation method and use thereof. The divalent platinum complex provided by the present invention has a structure as shown in Formula I. The divalent platinum complex provided by the present invention can emit yellow phosphorescence as a phosphorescent material, and has good color purity, good stability and high efficiency, and is suitable as an organic yellow phosphorescent light emitter in OLED related products.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic materials, and in particular to a divalent platinum complex and a preparation method and application thereof. Background Art

[0002] Organic electroluminescence refers to the luminescence process in which organic materials convert electrical energy into light energy after being excited by electric current and electric field. This electroluminescence phenomenon was first discovered by Professor Pope of New York University in the United States in 1963. Compared with inorganic luminescent materials, organic luminescent materials can be closer to the demand for light adaptability. Displays and light emitters manufactured based on organic light-emitting diode (OLED) technology have flexible appearances and add many artistic elements to electronic devices. The earliest organic electroluminescent device was developed by Eastman Kodak, using aromatic amine organic small molecules as hole transport layers and 8-hydroxyquinoline aluminum as light-emitting layers. This type of device with organic molecules as the core luminescent material is called organic light-emitting diode (OLED), which can be applied to new display and lighting fields and has many advantages and potentials. Light-emitting devices made of organic materials have the advantages of high quantum efficiency, high brightness, and high luminous efficiency; light-emitting devices made of organic luminescent materials have the advantages of light, thinness, and softness in appearance, especially the ability to be made into flexible devices, which is an advantage that other luminescent materials cannot compare with. According to the core electroluminescent materials, traditional OLEDs can be divided into fluorescent OLEDs and phosphorescent OLEDs. Compared with fluorescent OLEDs (theoretical luminous efficiency up to 25%), phosphorescent OLEDs (theoretical luminous efficiency 100%) have become the mainstream direction of OLED technology research and development due to their higher luminous efficiency.

[0003] At present, yellow phosphorescent materials are mainly used in lighting display and yellow light, such as TV backplane technology, car turn signal, etc. In terms of luminescence, yellow is a "combination" color. It is not one of the three primary colors of "RGB". It is a light color composed of equal amounts of red light and green light. Therefore, in color science, yellow phosphorescence is formed by filtering out blue light from white phosphorescence, and is often the complementary color auxiliary light color of blue light. Yellow phosphorescent heavy metal complexes are not only an indispensable component to meet the requirements of full-color displays, but they also greatly contribute to the realization of high-performance two-color (blue and yellow) white light diodes, which show advantages in device efficiency and manufacturing cost compared with three-color (blue, green and red) analogs as solid-state light sources. At the same time, in the four-color (blue, green, yellow and red) spectrum, yellow phosphorescent heavy metal complexes are conducive to improving device efficiency and color rendering index / color temperature index. At present, the development of yellow phosphorescent materials also faces many challenges. The single-molecule luminescence spectrum of many materials is not wide enough to cover all green and red parts, and cannot meet the requirements of standard yellow light, which greatly limits its practical application. Therefore, the development of yellow phosphorescent materials with high efficiency, wide spectrum, stability and long working life has practical application value in display and lighting. Summary of the invention

[0004] In view of the deficiencies in the prior art, the object of the present invention is to provide a yellow phosphorescent material with high efficiency, wide spectrum, stability and long working life, and further to provide a divalent platinum complex and a preparation method and use thereof.

[0005] The scheme adopted by the present invention is as follows:

[0006] A divalent platinum complex having the structure shown below:

[0007]

[0008] Among them, R1-R 15 are the same or different, and are independently selected from hydrogen, halogen, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C3-C30 cycloalkenyl, substituted or unsubstituted C3-C30 heteroaryl, and substituted or unsubstituted C3-C30 silanyl.

[0009] Preferably, R1-R 15 The same or different, independently selected from deuterium, -CDH2, -CD2H, -CD3, -CDR b R c 、-CD2R d , where R b -R dThe same or different, each independently selected from substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C3-C30 cycloalkenyl, substituted or unsubstituted C3-C30 heteroaryl, substituted or unsubstituted C3-C30 silanyl.

[0010] Preferably, the substituted C1-C30 alkyl, substituted C6-C30 aryl, substituted C3-C30 cycloalkyl, substituted C3-C30 cycloalkenyl, substituted C3-C30 heteroaryl, substituted C3-C30 silyl may be optionally substituted with one or more substituents R a Replace; each R a Independently selected from hydrogen, halogen, C1-C30 alkyl, and C6-C30 aryl.

[0011] Preferably, the hydrogen may be deuterium; the halogen is selected from fluorine, chlorine, and bromine; the C1-C30 alkyl is selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl, and tert-butyl; the C6-C30 aryl is selected from phenyl, naphthyl, and biphenyl; and the C3-C30 cycloalkyl is selected from cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl.

[0012] Preferably, R1-R 15the same or different, each independently selected from methyl, deuterated methyl, benzyl, diphenylmethyl, triphenylmethyl, ethyl, 2-phenylethyl, 2,2-phenylethyl, 2,2,2-trifluoroethyl, propyl, isopropyl, 3,3,3-trifluoropropyl, 1,1,1,3,3,3-hexafluoro-2-propyl, butyl, isobutyl, hexafluoroisobutyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, phenyl, 2-methylphenyl, 2-isopropylphenyl, 2-ethylphenyl phenyl, 2,3-dimethylphenyl, 2,3-diethylphenyl, 2,3-diisopropylphenyl, 2,3-diisobutylphenyl, 2,3-dicyclohexylphenyl, 2,3-dicyclopropylphenyl, 2,3-dicyclobutylphenyl, 2,3-dicyclopentylphenyl, 2,4-dimethylphenyl, 2,4-diethylphenyl, 2,4-diisopropylphenyl, 2,4-diisobutylphenyl, 2,4- dicyclohexylphenyl, 2,4-dicyclopropylphenyl, 2,4-dicyclobutylphenyl, 2,4-dicyclopentylphenyl, 2,6-dimethylphenyl, 2,6-diethylphenyl, 2,6-diisopropylphenyl, 2,6-diisobutylphenyl, 2,6-dicyclohexylphenyl, 2,6-dicyclopropylphenyl, 2,6-dicyclobutylphenyl, 2,6-dicyclopentylphenyl, 3,5-dimethylphenyl, 3,5-diethylphenyl, 3,5-diisopropylphenyl, 3,5-diisobutylphenyl phenyl, 3,5-dicyclohexylphenyl, 3,5-dicyclopropylphenyl, 3,5-dicyclobutylphenyl, 3,5-dicyclopentylphenyl, 2,3,5,6-tetramethylphenyl, 2,4,6-trimethylphenyl, 2,4,6-triethylphenyl, 2,4,6-triisopropylphenyl, 2,4,6-triisobutylphenyl, 2,4,6-tricyclohexylphenyl, 2,4,6-tricyclopropylphenyl, 2,4,6-tricyclobutylphenyl, 2,4,6-tricyclopentylphenyl.

[0013] Preferably, the divalent platinum complex has the structure shown below:

[0014]

[0015]

[0016]

[0017] The divalent platinum complex provided by the present invention, by introducing a dibenzofuran structure into the ligand of the divalent platinum complex, the complex tends to form an aggregate with platinum-platinum interaction or π-π stacking, and can produce red-shifted aggregate emission. The degree of the MM interaction or π-π stacking is closely related to the intermolecular distance, and it emits green light in a single molecule and emits red light in an aggregated state; it can simultaneously realize single molecule and aggregated state luminescence, and is a spectrally tunable phosphorescent luminescent material; the dual emission mechanism emits light with high efficiency and wide spectrum, and can realize the regulation of the ratio of luminescence peaks in the range of about 540nm and 600nm. The molecular dual emission mechanism is as follows:

[0018]

[0019] The present invention also provides a method for preparing the above-mentioned divalent platinum complex, comprising the following steps:

[0020] The compound represented by A and the compound represented by B are subjected to coupling reaction to obtain the compound represented by intermediate 1; the compound represented by intermediate 1 and platinum salt are subjected to cyclometallation reaction to obtain the compound represented by formula I;

[0021] The preparation route of the compound represented by formula I is as follows:

[0022]

[0023] Wherein X1 is a halogen, preferably, X1 is bromine or chlorine, and X2 is a coupling group, preferably, X2 is a tin group or a boron group.

[0024] The present invention also provides a use of the divalent platinum complex described above or the divalent platinum complex prepared by the preparation method described above in an organic photoelectric device.

[0025] Preferably, the divalent platinum complex is used as a phosphorescent light-emitting material in the organic optoelectronic device. Preferably, the divalent platinum complex is used as a yellow phosphorescent light-emitting material in the organic optoelectronic device.

[0026] The present invention also provides an organic photoelectric device, comprising a positive electrode, a negative electrode and an organic layer arranged between the positive electrode and the negative electrode, wherein the organic layer comprises any one or a combination of at least two of the above-mentioned divalent platinum complexes.

[0027] Preferably, the organic layer comprises a light-emitting layer, and the light-emitting layer comprises any one or a combination of at least two of the above-mentioned divalent platinum complexes;

[0028] Preferably, the light-emitting layer contains a host material and a doping material, and the host material or the doping material includes any one or a combination of at least two of the above-mentioned divalent platinum complexes.

[0029] Preferably, the organic photoelectric device is a yellow light organic photoelectric device.

[0030] The present invention also provides use of the divalent platinum complex described above or the divalent platinum complex prepared by the preparation method described above in a display device or a lighting device.

[0031] Optionally, the divalent platinum complex is used in lighting, display, and special yellow light organic optoelectronic devices.

[0032] The organic layer of the organic electroluminescent device of the present application may be composed of a single-layer structure, but may also be composed of a multilayer structure in which two or more organic layers are stacked. For example, as a representative example of the organic electroluminescent device of the present invention, the organic electroluminescent device may have a structure including a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, etc. as an organic material layer. However, the structure of the organic electronic device is not limited thereto, and may include a smaller number of organic layers.

[0033] In an exemplary embodiment of the present application, the first stack and the second stack are each an organic material layer including a light-emitting layer, and in addition to the light-emitting layer, the organic material layer may also include one or more organic material layers, such as a hole injection layer, a hole buffer layer, a hole transport layer, an electron blocking layer, a hole blocking layer, an electron transport layer and an electron injection layer.

[0034] Optionally, the organic layer includes a light-emitting layer, and the light-emitting layer includes any one or a combination of at least two of the above-mentioned organic metal complexes.

[0035] The organic electroluminescent device of the present invention can be manufactured by materials and methods known in the art, except that one or more layers of the organic material layer contain the compound of the present invention, ie, the compound.

[0036] When the organic electroluminescent device includes a plurality of organic layers, the organic layers may be formed of the same material or different materials.

[0037] The organic electroluminescent device of the present invention can be manufactured by materials and methods known in the art, except that one or more layers of the organic layer contain the compound of the present invention, i.e., the compound represented by formula I. For example, the organic electroluminescent device of the present invention can be manufactured by stacking the first electrode, the organic layer, and the second electrode on a substrate in sequence. In this case, the organic electroluminescent device can be manufactured as follows: by using a physical vapor deposition (PVD) method such as sputtering or electron beam evaporation, a metal or a conductive metal oxide or an alloy thereof is deposited on a substrate to form a positive electrode, an organic layer including a hole injection layer, a hole transport layer, a light-emitting layer, and an electron transport layer is formed thereon, and then a material that can be used as a negative electrode is deposited thereon. In addition to the method described above, an organic electronic device can be manufactured by depositing a negative electrode material, an organic layer, and a positive electrode material on a substrate in sequence.

[0038] In addition, when manufacturing an organic electroluminescent device, the compound of formula I can be formed into an organic layer not only by a vacuum deposition method but also by a solution application method. Here, the solution application method means spin coating, dip coating, blade coating, inkjet printing, screen printing, spraying, roller coating, etc., but is not limited thereto.

[0039] Optionally, the preparation method includes placing a crucible containing OLED organic material and a crucible containing metal aluminum particles on the positions of the organic evaporation source and the inorganic evaporation source in sequence. The cavity is closed, and the initial vacuum and high vacuum steps are performed, so that the vacuum degree of evaporation inside the OLED evaporation equipment reaches 10-7Torr. OLED evaporation film forming method: open the OLED organic evaporation source, preheat the OLED organic material to 100°C, and the preheating time is 15 minutes to ensure that the water vapor in the OLED organic material is further removed. Then, the organic material to be evaporated is subjected to rapid heating treatment, and the baffle above the evaporation source is opened until the evaporation source of the material has organic material running out, and at the same time, the crystal oscillator detector detects the evaporation rate, and then slowly heats up, the temperature rise is 3°C, until the evaporation rate is stable at 1A / second, the baffle directly below the mask plate is opened, and the OLED film is formed. When the computer observes that the organic film on the ITO substrate reaches the preset film thickness, the mask plate baffle and the baffle directly above the evaporation source are closed, and the evaporation source heater of the organic material is closed. The evaporation process of other organic materials and cathode metal materials is as described above. UV epoxy resin is used for light curing packaging.

[0040] In an exemplary embodiment of the present application, the first electrode is a positive electrode, and the second electrode is a negative electrode, and in another exemplary embodiment, the first electrode is a negative electrode, and the second electrode is a positive electrode.

[0041] As the positive electrode material, a material having a large work function is generally preferred to smoothly inject holes into the organic material layer. Specific examples of the positive electrode material that can be used in the present invention include: metals such as vanadium, chromium, copper, zinc and gold, or alloys thereof; metal oxides such as zinc oxide, indium oxide, indium tin oxide (ITO) and indium zinc oxide (IZO); combinations of metals and oxides such as ZnO:Al or SnO2:Sb; conductive polymers such as poly (3-methylthiophene), polypyrrole and polyaniline, etc., but are not limited thereto.

[0042] As the negative electrode material, a material having a small work function is generally preferred to smoothly inject electrons into the organic layer. Specific examples of the negative electrode material include: metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin and lead, or alloys thereof; multilayer structure materials such as LiF / Al or LiO2 / Al, etc., but are not limited thereto.

[0043] The hole injection layer is a layer that injects holes from the electrode, and the hole injection material is preferably a compound that has the ability to transport holes, and therefore has the effect of injecting holes at the positive electrode and the excellent effect of injecting holes into the light-emitting layer or the light-emitting material, preventing the excitons generated by the light-emitting layer from migrating to the electron injection layer or the electron injection material, and is also excellent in the ability to form a thin film. Preferably, the highest occupied molecular orbital (HOMO) of the hole injection material is between the work function of the positive electrode material and the HOMO of the surrounding organic material layer. Specific examples of hole injection materials include metal porphyrins, oligothiophenes, organic materials based on arylamines, organic materials based on hexanitrile hexaazatriphenylene, organic materials based on quinacridone, organic materials based on perylene, anthraquinone, conductive polymers based on polyaniline and polythiophene, etc., but are not limited thereto.

[0044] The hole transport layer is a layer that receives holes from the hole injection layer and transports the holes to the light-emitting layer, and the hole transport material is appropriately a material that can receive holes transmitted from the positive electrode or the hole injection layer to transfer the holes to the light-emitting layer and has high mobility for the holes. Specific examples thereof include organic materials based on arylamine, conductive polymers, block copolymers having both conjugated and non-conjugated parts, etc., but are not limited thereto.

[0045] The light-emitting layer material is preferably a material that can receive holes and electrons transported by the hole transport layer and the electron transport layer, respectively, and combine the holes and electrons to emit light in the visible light region and has good quantum efficiency for fluorescence or phosphorescence. Specific examples thereof include: 8-hydroxy-quinoline aluminum complex (Alq3); carbazole-based compounds; diphenylethylene compounds; BAlq; 10-hydroxybenzoquinoline-metal compounds; compounds based on benzoxazole, benzothiazole and benzimidazole; polymers based on poly (p-phenylene vinylene) (PPV); spiro compounds; polyfluorene; rubrene, etc., but are not limited thereto.

[0046] The light-emitting layer may include a host material and a dopant material. Examples of the host material include fused aromatic ring derivatives or heterocyclic compounds, etc. Specific examples of fused aromatic ring derivatives include anthracene derivatives, pyrene derivatives, naphthalene derivatives, pentacene derivatives, phenanthrene compounds, fluoranthene compounds, etc., and specific examples of heterocyclic compounds include compounds, dibenzofuran derivatives, ladder-type furan compounds, pyrimidine derivatives, etc., but examples thereof are not limited thereto.

[0047] The electron transport layer is a layer that receives electrons from the electron injection layer and transfers the electrons to the light-emitting layer, and the electron transport material is suitably a material that can well receive electrons from the negative electrode and transfer the electrons to the light-emitting layer and has a high mobility for electrons. Specific examples thereof include: Al complexes of 8-hydroxyquinoline, complexes containing Alq3, organic free radical compounds, hydroxyflavone-metal complexes, etc., but are not limited thereto. The electron transport layer can be used with any desired cathode material used according to the prior art. In particular, suitable examples of cathode materials are typical materials with low work functions, followed by an aluminum layer or a silver layer. Specific examples thereof include cesium, barium, calcium, ytterbium and samarium, in each case followed by an aluminum layer or a silver layer.

[0048] The electron injection layer is a layer that injects electrons from the electrode, and the electron injection material is preferably a compound that has the ability to transport electrons, has an effect of injecting electrons from the negative electrode and an excellent effect of injecting electrons into the light-emitting layer or the light-emitting material, prevents the excitons generated in the light-emitting layer from migrating to the hole injection layer, and is also excellent in the ability to form a thin film. Specific examples thereof include fluorenone, anthraquinone dimethane, diphenoquinone, thiopyran dioxide, azole, diazole, triazole, imidazole, perylene tetracarboxylic acid, fluorenyl methane, anthrone, and the like and derivatives thereof, metal complex compounds, nitrogen-containing 5-membered ring derivatives, and the like, but are not limited thereto.

[0049] The hole blocking layer is a layer that blocks holes from reaching the negative electrode and can generally be formed under the same conditions as the hole injection layer. Specific examples thereof include diazole derivatives or triazole derivatives, phenanthroline derivatives, aluminum complexes, etc., but are not limited thereto.

[0050] The organic light emitting device according to the present specification may be a top emission type, a bottom emission type, or a double-side emission type according to the materials used.

[0051] Beneficial effects of the present invention:

[0052] The divalent platinum complex provided by the present invention tends to form aggregates with platinum-platinum interaction or π-π stacking by introducing a dibenzofuran structure into the ligand of the divalent platinum complex, and can produce red-shifted aggregate emission. The degree of the MM interaction or π-π stacking is closely related to the intermolecular distance, and green light is emitted in a single molecule and red light is emitted in an aggregated state. Single molecule and aggregated state luminescence can be achieved simultaneously, and the complex is a spectrally tunable phosphorescent luminescent material. The dual emission mechanism emits light with high efficiency and wide spectrum, and the half-peak width can reach up to 140nm, and the luminescence peak ratio in the range of about 540nm and 600nm can be controlled. The series of platinum complexes can be used to develop yellow light monochromatic devices, and can also be used for white light devices, and can be applied to products of lighting, display and special yellow lamps.

[0053] The divalent platinum complex is a yellow phosphorescent material. As a phosphorescent material, it can emit yellow phosphorescence, and has good color purity, good stability and high efficiency. It is completely suitable as an organic yellow phosphorescent light emitter in OLED related products. In addition, the compounds provided by the present invention are easy to prepare and sublimate and purify, soluble in general organic solvents, and can be suitable for device processes processed by both evaporation and solution methods. At the same time, the luminescent performance of the material has the characteristics of low energy and good color purity, which comprehensively surpasses various fluorescent materials in the prior art, and at the same time achieves the effect of emitting yellow phosphorescent light and improving device performance; the stable complex luminescent material provided by the present invention, its CIE coordinates and luminous efficiency are more in line with the needs of flat panel displays, and has great development potential in the fields of display and lighting. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0055] Figure 1 is the luminescence spectrum of complex 1 in solution;

[0056] Figure 2 is the luminescence spectrum of complex 2 in the film;

[0057] Figure 3 is the luminescence spectrum of complex 3 in the film;

[0058] Figure 4 is the UV-visible absorption spectrum of complex 2;

[0059] Figure 5 is the concentration-dependent luminescence spectrum of complex 2 in the film;

[0060] Figure 6 For complex 2 1 H NMR spectrum;

[0061] Figure 7 For complex 3 1 H NMR spectrum;

[0062] Figure 8 is the mass spectrum of complex 1;

[0063] Fig. 9 is the mass spectrum of complex 2;

[0064] Fig.10 is the mass spectrum of complex 3;

[0065] Fig.11 is a cross-sectional view of an OLED device of the present invention;

[0066] Fig.12 The electroluminescence spectrum of the organic photovoltaic device of complex 2;

[0067] Fig.13 Lifetime diagram of the device prepared for complex 2;

[0068] Fig.14 The relationship between voltage and current density of the device prepared for complex 2;

[0069] Fig.15 The relationship between voltage and luminescence brightness of the device prepared for complex 2;

[0070] Description of reference numerals:

[0071] 1- anode layer, 2- hole injection layer, 3- hole transport layer, 4- light emitting layer, 5- electron transport layer, 6- cathode layer. DETAILED DESCRIPTION

[0072] The following examples are provided for a better understanding of the present invention, but are not intended to limit the best mode of implementation, nor to limit the content and protection scope of the present invention. Any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior arts shall fall within the protection scope of the present invention.

[0073] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in the field can be used. If no manufacturer is specified for the reagents or instruments used, they are all conventional reagent products that can be obtained commercially.

[0074] In the following specific embodiments of the present invention, complexes 1, 2 and 3 are taken as examples to specifically illustrate the synthesis method, properties and performance of the divalent platinum complex provided by the present invention when used as a luminescent material.

[0075]

[0076] The various preparation methods of the compounds provided by the present invention are exemplary. These methods are used to illustrate various preparation methods, but are not intended to be limited to any specific method, and the temperature, catalyst, concentration, reactant composition and other process conditions may vary.

[0077] In addition, in the embodiments, the concentrations of the samples were recorded by a Varian liquid NMR spectrometer in a CDCl3 or DMSO-d6 solution. 1 HNMR (hydrogen nuclear magnetic resonance) and 13 C NMR spectra were recorded at 300, 400 or 500 MHz, and chemical shifts were based on residual protonated solvent. If CDCl3 was used as solvent, tetramethylsilane (δ = 0.00 ppm) was used as an internal reference. 1 H NMR (hydrogen nuclear magnetic resonance) spectrum; recorded using CDCl3 (δ = 77.00 ppm) as an internal reference 13 C NMR (carbon nuclear magnetic resonance) spectrum. If DMSO-d6 is used as solvent, residual H2O (δ=3.33 ppm) is used as an internal reference to record 1 H NMR (hydrogen nuclear magnetic resonance) spectrum; recorded using DMSO-d6 (δ = 39.52 ppm) as an internal reference 13 C NMR (carbon nuclear magnetic resonance) spectroscopy. The following abbreviations are used to explain 1 H NMR (hydrogen nuclear magnetic resonance) multiplicity: s = singlet, d = doublet, t = triplet, q = quadruplet, p = quintet, m = multitet, br = broad.

[0078] Example 1

[0079] This embodiment provides a complex 1, and the preparation method thereof specifically comprises the following steps:

[0080] 1) Synthesis of 2-(2-(3-(1-(1H-pyrazol-1-yl)phenoxy)dibenzo[b,d]furan-4-yl)pyridine:

[0081]

[0082] In a glove box, 1-(3-((4-chlorodibenzo[b,d]furan-2-yl)oxy)phenyl)-1H-pyrazole (540 mg, 1.5 mmol), 2-(tributylstannyl)pyridine (552 mg, 1.5 mmol), palladium acetate (21.9 mg, 0.025 mmol), tri-tert-butylphosphine (18 mg, 0.09 mmol), cesium fluoride (500 mg, 3.3 mmol) and 1,4-dioxane (3 mL) were added to a 15 mL sealed tube equipped with a magnetic rotor. The resulting mixture was bubbling nitrogen for 1 hr. After 10 minutes, the mixture was heated to 120° C. and stirred for 48 hours. The mixture was cooled to room temperature, and water was added to quench the reaction. A saturated aqueous solution of potassium fluoride was added and stirred at room temperature overnight. The mixture was then extracted with ethyl acetate. The organic phases were combined, washed with an appropriate amount of a saturated aqueous solution of sodium chloride, and dried over anhydrous sodium sulfate. The solvent was removed by distillation under reduced pressure. The crude product was separated and purified by silica gel column chromatography with petroleum ether: ethyl acetate = 10: 1 (volume ratio) as the eluent to obtain 2-(2-(3-(1-(1H-pyrazol-1-yl)phenoxy)dibenzo[b,d]furan-4-yl)pyridine as a yellow solid in a yield of 30%.

[0083] 2) Synthesis of complex 1:

[0084]

[0085] 2-(2-(3-(1-(1H-pyrazol-1-yl)phenoxy)dibenzo[b,d]furan-4-yl)pyridine (53 mg, 0.13 mmol), potassium chloroplatinite (58 mg, 0.14 mmol) and acetic acid (13 mL) were added to a 75 mL sealed tube with a magnetic rotor. The resulting mixture was bubbling with nitrogen for 10 minutes, stirred at 30°C for 24 hours, heated to 120°C and stirred for 24 hours, cooled to room temperature, quenched with water, extracted with dichloromethane, and the organic phases were combined, washed with an appropriate amount of saturated sodium chloride aqueous solution, and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure, and the crude product was separated and purified by silica gel column chromatography, the eluent was dichloromethane: petroleum ether = 1:1 (volume ratio), to obtain a yellow solid complex 1 with a yield of 50%.

[0086] Example 2

[0087] This embodiment provides a complex 2, and its preparation method specifically comprises the following steps:

[0088] 1) Synthesis of 2-(2-(3-(3,5-dimethyl-1H-pyrazol-1-yl)phenoxy)dibenzo[b,d]furan-4-yl)pyridine:

[0089]

[0090] In a glove box, 1-(3-((4-chlorodibenzo[b,d]furan-2-yl)oxy)phenyl)-3,5-dimethyl-1H-pyrazole (800 mg, 2.1 mmol), 2-(tributylstannyl)pyridine (1.5 g, 4.2 mmol), palladium acetate (27.45 mg, 0.03 mmol), tri-tert-butylphosphine (26.3 mg, 0.13 mmol), cesium fluoride (632 mg, 4.16 mmol) and 1,4-dioxane (10 mL) were added to a 48 mL sealed tube with a magnetic rotor, and the resulting mixture was purged with nitrogen. After bubbling for 10 minutes, the mixture was heated to 120° C. and stirred for 48 hours. The mixture was cooled to room temperature, and water was added to quench the reaction. A saturated aqueous solution of potassium fluoride was added and stirred at room temperature overnight. The mixture was then extracted with ethyl acetate. The organic phases were combined, washed with an appropriate amount of a saturated aqueous solution of sodium chloride, and dried over anhydrous sodium sulfate. The solvent was removed by distillation under reduced pressure. The crude product was separated and purified by silica gel column chromatography with petroleum ether: ethyl acetate = 10: 1 (volume ratio) as the eluent to obtain 2-(2-(3-(3,5-dimethyl-1H-pyrazol-1-yl)phenoxy)dibenzo[b,d]furan-4-yl)pyridine as a yellow solid in a yield of 35%.

[0091] 2) Synthesis of complex 2:

[0092]

[0093] 2-(2-(3-(3,5-dimethyl-1H-pyrazol-1-yl)phenoxy)dibenzo[b,d]furan-4-yl)pyridine (780 mg, 1.8 mmol), potassium chloroplatinite (815 mg, 1.9 mmol)) and acetic acid (150 mL) were added to a 350 mL sealed tube with a magnetic rotor. The resulting mixture was bubbling with nitrogen for 10 minutes, stirred at 30°C for 24 hours, heated to 120°C and stirred for 24 hours, cooled to room temperature, quenched with water, extracted with dichloromethane, and the organic phases were combined, washed with an appropriate amount of saturated sodium chloride aqueous solution, and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure, and the crude product was separated and purified by silica gel column chromatography, the eluent was dichloromethane: petroleum ether = 1:1 (volume ratio), to obtain a yellow solid complex 2 with a yield of 70%.

[0094] Example 3

[0095] This embodiment provides a complex 3, and its preparation method specifically comprises the following steps:

[0096] 1) Synthesis of 3,5-dimethyl-1-(3-(((4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolane-2-yl)dibenzo[b,d]furan-2-yl)oxy)phenyl)-1H-pyrazole:

[0097]

[0098] To a 15 mL sealed tube equipped with a magnetic rotor was added 1-(3-((4-chlorodibenzo[b,d]furan-2-yl)oxy)phenyl)-3,5-dimethyl-1H-pyrazole (24.75 mg, 0.11 mmol), bipyraclostrobin (55 mg, 0.22 mmol), bis(dibenzylideneacetone)palladium (7 mg, 0.0075 mmol), tricyclohexylphosphine (5 mg, 0.018 mmol), potassium acetate (37 mg, 0.4 mmol) and 1,4-dioxane (1.5 mL), and the resulting mixture was bubbling with nitrogen for 10 min. The mixture was heated to 120°C and stirred for 24 hours, cooled to room temperature, and water was added to quench the reaction. The mixture was extracted with ethyl acetate, and the organic phases were combined, washed with an appropriate amount of saturated sodium chloride aqueous solution, and dried over anhydrous sodium sulfate. The solvent was removed by distillation under reduced pressure, and the crude product was separated and purified by silica gel column chromatography with petroleum ether:ethyl acetate = 10:1 as the eluent to obtain 3,5-dimethyl-1-(3-(((4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)dibenzo[b,d]furan-2-yl)oxy)phenyl)-1H-pyrazole as a yellow solid in a yield of 50%.

[0099] 2) Synthesis of 4-(tert-butyl)-2-(2-(3-(3-,3,5-dimethyl-1H-pyrazol-1-yl)phenoxy)dibenzo[b,d]furan-4-yl)pyridine:

[0100]

[0101] To a 15 mL sealed tube equipped with a magnetic rotor were added 3,5-dimethyl-1-(3-(((4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)dibenzo[b,d]furan-2-yl)oxy)phenyl)-1H-pyrazole (148 mg, 0.3 mmol), 2-bromo-5-(tert-butyl)pyridine (92 mg, 0.75 mmol), tetrakistriphenylphosphine palladium (11 mg, 0.009 mmol), potassium carbonate (62 mg, 0.45 mmol) and toluene (1 mL). The resulting mixture was stirred for 2 h. After nitrogen bubbling for 10 minutes, the mixture was heated to 100°C and stirred for 24 hours. The mixture was cooled to room temperature, and water was added to quench the reaction. The mixture was extracted with ethyl acetate, and the organic phases were combined, washed with an appropriate amount of saturated sodium chloride aqueous solution, and then dried over anhydrous sodium sulfate. The solvent was removed by distillation under reduced pressure, and the crude product was separated and purified by silica gel column chromatography. The eluent was petroleum ether: ethyl acetate = 8: 1 (volume ratio) to obtain 4-(tert-butyl)-2-(2-(3-(3-, 3,5-dimethyl-1H-pyrazol-1-yl)phenoxy)dibenzo[b,d]furan-4-yl)pyridine as a yellow solid in a yield of 75%.

[0102] 3) Synthesis of Complex 3

[0103]

[0104] To a 75 mL sealed tube with a magnetic rotor were added 4-(tert-butyl)-2-(2-(3-(3-,3,5-dimethyl-1H-pyrazol-1-yl)phenoxy)dibenzo[b,d]furan-4-yl)pyridine (70 mg, 0.13 mmol), potassium chloroplatinite (62 mg, 0.15 mmol)) and acetic acid (10 mL). The resulting mixture was bubbling with nitrogen for 10 minutes, stirred at 30°C for 24 hours, heated to 120°C and stirred for 24 hours, cooled to room temperature, quenched with water, extracted with dichloromethane, combined organic phases, washed with an appropriate amount of saturated sodium chloride aqueous solution, and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure, and the resulting crude product was separated and purified by silica gel column chromatography, the eluent being dichloromethane: petroleum ether = 1:1 (volume ratio) to obtain a yellow solid complex 3, with a yield of 50%.

[0105] Device Example 1

[0106] This embodiment provides an organic electroluminescent device. The cross-sectional view of the OLED device in Embodiments 1-3 is as follows: Fig.11 It is shown that platinum complexes 1, 2 and 3 are respectively doped into the main material as light-emitting materials to prepare OLED devices, and the doping amount is 5-10%. The OLED device is prepared, ITO is the anode (Anode) of the OLED device, Al is the cathode (Cathode) of the OLED device, and the device structure is: ITO / HIL / HTL / EML / ETL / Al, wherein the HIL hole injection layer can be but not limited to HATCN, Re2O3, and the HTL is the hole transport layer, which can be but not limited to TAPC, NP D, TCTA, PT301, BCP, mCP, m-MTDATA, TPTA, BTB, TPD, EML layer is the light-emitting layer complex: main material = 5%: 95% main material can be but not limited to CBP, mCBP, 2,6mCPy, 26DCzPPY, TCP, BPyPPM, DPEPO, ETL layer is the electron transport layer here can be but not limited to TmPyPb, TPBi, DPPS, Bphen, BmPyPb, DBFTrz, TpPyPb. Attachment:

[0107] HATCN (Chinese name: 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene material, English name: 2,3,6,7,10,11-Hexaazatriphenylenehexacabonitrile);

[0108] Re2O3 (Chinese name: molybdenum trioxide, English name: Molybdenum (VI) oxide);

[0109] TAPC (Chinese name: 4,4′-cyclohexylbis[N,N-di(4-methylphenyl)aniline], English name: 4,4′-cyclohexylidenebis[N,N-bis(p-tolyl)aniline];

[0110] NPD (Chinese name: N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, English name: N,N'-Bis-(1-naphthalenyl)-N,N'-bis-phenyl-(1,1'-biphenyl)-4,4'-diamine);

[0111] TCTA (Chinese name: 4,4′,4”-Tris(carbazol-9-yl)triphenylamine, English name: 4,4′,4”-Tris(carbazol–9-yl)triphenylamine);

[0112] PT301 (Chinese name: 4,4'-Bis[N,N-di(biphenyl-4-yl)amino]-1,1'-biphenyl, English name: 4,4'-Bis[N,N-di(biphenyl-4-yl)amino]-1,1'-biphenyl);

[0113] BCP (Chinese name: 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline, English name: 2,9-dimethyl-4,7-diphenyl-1,10-Phenanthroline);

[0114] mCP (Chinese name: 1,3-bis(N-carbazolyl)benzene, English name: 1,3-bis(N-carbazolyl)benzene);

[0115] m-MTDATA (Chinese name: 4,4′,4”-Tris[phenyl(m-tolyl)amino]triphenylamine, English name: 4,4′,4”-Tris[phenyl(m-tolyl)amino]triphenylamine);

[0116] TPTA (Chinese name: 4,4′,4”-trimethyltriphenylamine, English name: 4,4′,4”-Trimethyltriphenylamine);

[0117] BTB (Chinese name: 4,4'-bis(4,6-diphenyl-1,3,5-triazine-2-yl)biphenyl, English name: 4,4'-bis(4,6-diphenyl-1,3,5-Triazine-2-yl)biphenyl);

[0118] TPD (Chinese name: N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine, English name: N,N'-Bis(3-methylphenyl)-N,N'-bis(phenyl)benzidine);

[0119] CBP (Chinese name: 4,4'-di(9-carbazolyl)biphenyl, English name: 4,4'-Bis(9-carbazolyl)-1,1'-biphenyl);

[0120] mCBP (Chinese name: 3,3'-di(9H-carbazol-9-yl)-1,1'-biphenyl, English name: 3,3'-Di(9H-carbazol-9-yl)-1,1'-biphenyl (purified by sublimation);

[0121] 2,6mCPy (Chinese name: 2,6-di(9-carbazol-9-yl)pyridine, English name: 2,6-Di(9H-carbazol-9-yl)pyridine);

[0122] 26DCzPPY (Chinese name: 2,6-bis((9H-carbazol-9-yl)-3,1-phenylene)pyridine, English name: 2,6-bis(3-(9H-carbazol-9-yl)phenyl)pyridine);

[0123] TCP (Chinese name: 1,3,5-Tri(9-carbazolyl)benzene, English name: 1,3,5-Tri(9-carbazolyl)benzene);

[0124] BPyPPM (Chinese name: 2-phenyl-bis-4,6-(3,5-dipyridylphenyl)pyrimidine, English name: 2-phenyl-bis-4,6-(3,5-dipyridylphenyl)pyrimidine);

[0125] DPEPO (Chinese name: Bis[2-(diphenylphosphoryl)phenyl]ether Bis[2-(oxodiphenylphosphino)phenyl]ether, English name: Bis[2-(diphenylphosphoryl)phenyl]etherBis[2-(oxodiphenylphosphino)phenyl]ether)

[0126] TmPyPb (Chinese name: 3,3'-[5'-[3-(3-pyridyl)phenyl][1,1':3',1"-terphenyl]-3,3"-diyl]bipyridine, English name: 1,3,5-tri[(3-pyridyl)-phen-3-yl]benzene);

[0127] TPBi (Chinese name: 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, English name: 1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene);

[0128] DPPS (Chinese name: diphenylbis[4-(pyridin-3-yl)phenyl]silane, English name: Diphenylbis(4-(pyridin-3-yl)phenyl)silane);

[0129] Bphen (Chinese name: 4,7-diphenyl-1,10-phenanthroline, English name: 4,7-diphenyl-1,10-phenanthroline);

[0130] BmPyPb (Chinese name: 1,3-bis(3,5-dipyridin-3-ylphenyl)benzene, English name: 1,3-bis[3,5-di(pyridin-3-yl)phenyl]benzene);

[0131] DBFTrz (Chinese name: 2,8-bis(4,6-diphenyl-1,3,5-triazin-2-yl)dibenzo[b,d]furan)

[0132] TpPyPb (Chinese name: 1,3,5-Tri(4-pyrid-3-ylphenyl)benzene, English name: 1,3,5-Tri(4-pyrid-3-ylphenyl)benzene).

[0133] Device Example 2

[0134] This embodiment provides an organic electroluminescent device, such as Fig.11As shown, it includes an anode layer 1, a hole injection layer 2, a hole transport layer 3, a light-emitting layer 4, an electron transport layer 5 and a cathode layer 6 which are arranged on a glass substrate from bottom to top; the device structure is ITO / HIL (10nm) / HTL (50nm) / EML (30nm) / ETL (40nm) / Al (150nm).

[0135] Among them, the anode layer 1 is made of ITO material, that is, indium tin oxide material;

[0136] The hole injection layer 2 material is HATCN material;

[0137] The hole transport layer 3 material is TAPC material;

[0138] The light-emitting layer 4 is formed by co-doping a host material and a guest material, wherein the host material is mCBP material, and the guest material is complex 1, and the mass of complex 1 accounts for 5% of the total mass of the host material and the guest material;

[0139] The electron transport layer 5 material is Bphen;

[0140] The material of cathode layer 6 is metal Al.

[0141] Device Example 3

[0142] This embodiment provides an organic electroluminescent device, which is different from the organic electroluminescent device provided in device embodiment 2 in that the guest material in the light-emitting layer is complex 2.

[0143] Device Example 4

[0144] This embodiment provides an organic electroluminescent device, which is different from the organic electroluminescent device provided in device embodiment 2 in that the guest material in the light-emitting layer is complex 3.

[0145] As an alternative embodiment, the guest material of the light-emitting layer may also be selected from any of the complexes shown in Complexes 1-30.

[0146] As an alternative embodiment, the guest material of the light-emitting layer may also be selected from any other complex having the chemical structure shown in Formula I.

[0147] Test Example 1

[0148] The complex of the present invention was dissolved in dichloromethane (DCM) at a weight ratio of 5% to form a solution and doped in methyl methacrylate (PMMA) to obtain a film, and the obtained solution or film was tested as follows:

[0149] Photoelectric energy level test of electroluminescent materials: The band gap value (Eg), the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO) values ​​of the materials were measured by cyclic voltammetry (CV). The entire test process was carried out on a CHI600D electrochemical workstation (Shanghai Chenhua Instrument Company) in a glove box (Lab2000, Etelux), with a Pt column as the working electrode, Ag / AgCl as the reference electrode, and a Pt wire as the auxiliary electrode to form a three-electrode system. The medium used in the test process was a 0.1M tetrabutylammonium hexafluorophosphate (Bu4NPF6) dimethylformamide (DMF) solution, and the measured potentials were all measured with the added ferrocene (Fc) as the internal standard. Where λ is the peak wavelength of the divalent platinum complex dissolved in dichloromethane, FWHM is the half-peak width, and the triplet photon energy (ET1) of the material is calculated by the formula 1240 / λ0→1 (λ0→1 is the first vibration peak under 77K conditions), and the unit is electron volt (eV). The test results are shown in Tables 1 and 2.

[0150] Table 1 Luminescence properties of the complexes

[0151]

[0152] Wherein: a dichloromethane solution, b PMMA film

[0153] Table 2 Energy level data of complexes

[0154]

[0155] From the data in Table 1, it can be seen that the peak wavelength of the complex prepared by the present invention is between 530 and 542 nm, the half-peak width is about 52-68 nm, and the photoluminescence fluorescence efficiency is 63-99%, indicating that the divalent platinum complex having the structure of general formula I is a high-efficiency wide-spectrum yellow phosphorescent luminescent material. From the data in Table 2, it can be seen that the triplet energy of the divalent platinum complex of complex 2 is 2.34 eV, which is mainly related to the parent core structure.

[0156] Figure 1 The luminescence spectrum of complex 1 in solution is shown; under 380nm ultraviolet light excitation, the luminescence wavelength in dichloromethane solution is 530nm, and the wavelength of the complex is in the yellow phosphorescence region. Due to the large space between molecules in the solution, there is no aggregated luminescence, and it is single molecule emission. This shows that the complex is an excellent yellow light emitting material.

[0157] Figure 2The luminescence spectrum of platinum complex 2 in the film is shown. Under 380nm ultraviolet light excitation, the luminescence wavelength in PMMA is 540nm, the half-peak width is 71nm, and an obvious emission spectrum appears at 650nm. The emission spectrum here is attributed to the good molecular planarity and the aggregated luminescence produced in the film, which makes the spectrum wider and better covers the green and red light regions, so the wavelength of the complex is in the yellow phosphorescence region.

[0158] Figure 3 The luminescence spectrum of complex 3 in the film is shown. Under 380nm ultraviolet light excitation, the luminescence wavelength in PMMA is 534nm, and the half-peak width is 62nm. Compared with complex 2, the spectrum of complex 3 in the film is blue-shifted. Like complex 2, there is also an obvious emission spectrum at 650nm. The emission spectrum at this location is also attributed to the good molecular planarity, which causes aggregated luminescence in the film.

[0159] Figure 4 The UV-visible absorption spectrum of complex 2 in DCM solution is shown. According to the absorption spectrum, it can be seen that the absorption spectrum is very strong in the range of 200-400nm. Among them, complex 2 has a strong absorption band around 225-300nm, which is attributed to the 1LC (π-π*) transition allowed by the ligand spin; the absorption band in the range of 350-400nm is attributed to the spin-allowed metal-to-ligand charge transfer transition (1MLCT) and ligand-to-ligand charge transfer transition (1LLCT); the weak absorption band above 400nm belongs to the spin-forbidden 3MLCT and 3LC transitions. This type of molecule has very efficient energy absorption and can be used as the preferred molecular structure of doping material molecules.

[0160] Figure 5 It is the concentration-dependent luminescence spectrum of complex 2 in the film. According to the concentration-dependent spectrum, it can be seen that as the doping concentration of complex 2 in the film increases, the luminescence of the molecular aggregate state becomes more obvious, and the molecules show dual emission characteristics of single molecule and aggregate state. The single molecule luminescence shows green light emission, and the aggregated state luminescence shows red light emission. The spectrum becomes wider, and the maximum half-peak width reaches 165nm, which covers the green and red light spectral regions. It is a very good yellow light material.

[0161] Test Example 2

[0162] The organic electroluminescent devices provided in device embodiments 2-4 were tested, and the results are shown in Table 3:

[0163] Table 3 Device performance test results

[0164]

[0165] Table 3 shows the optical properties of phosphorescent devices prepared by complexes 1, 2 and 3. The peak wavelengths of the devices involved in device examples 2-4 are 535nm, 547nm and 540nm, respectively, and the half-peak widths reach 128nm, 118nm and 116nm. The CIE coordinate values ​​are (0.55, 0.45), (0.50, 0.48) and (0.52, 0.49), which cover the yellow light range very well. The highest current efficiency energy efficiency (PE) of this type of device is 40.2lm·W-1, the highest current efficiency (CE) is 35.2cd·A-1, and the highest external quantum efficiency (EQE) reaches 16.1%, which is a high-efficiency light-emitting device.

[0166] Fig.12 It is the electroluminescence spectrum of the organic photoelectric power generation device of complex 2. The horizontal axis is wavelength and the vertical axis is normalized intensity. The emission spectrum is a dual emission state. The maximum emission wavelengths are 547nm and 590nm respectively, and the half-peak width is 118nm. The spectrum covers the green and red light regions. It is a good yellow light spectrum. The chromaticity coordinate value is calculated to be CIE (0.50, 0.48), indicating that this device is suitable for use as a yellow light emitting device.

[0167] Fig.13 The OLED device prepared by using complex 2 as yellow light doping material at room temperature was tested for device life using a photoelectric testing system at 20 mA / cm2. The test results show that the light-emitting device using the platinum complex of the present invention is very stable and has a very long life. Fig.13 It can be seen that the prepared light-emitting device has a decay life LT97 of up to 162 hours at a brightness of 9000 cd / m2.

[0168] Fig.14 The current density-voltage test result diagram of the OLED device prepared by using complex 2 as a yellow light doping material at room temperature using a photoelectric testing system; the test results show that the light-emitting device using the complex of the present invention can perform charge transfer well.

[0169] Fig.15 The OLED device prepared by using complex 2 as a yellow light doping material at room temperature is subjected to brightness-voltage test using a photoelectric test system; the test results show that the light-emitting device using the complex of the present invention has a low turn-on voltage, thereby reducing power consumption and improving device efficiency. As shown in the figure, the turn-on voltage of the yellow light OLED device prepared by the present invention is 2.4V.

[0170] The present invention uses an exemplary example to illustrate that the general structure I can be used as a yellow phosphorescent doping material, and a single-doped yellow phosphorescent device and a white phosphorescent material device can be prepared, wherein each material is not limited to the exemplary structure; based on the application, the device structure can be either a bottom-emitting device or a top-emitting device. The ETL layer and the HTL may also contain one or more transport layer materials, and there may be another charge injection layer in the divalent platinum complex and close to the electrode. The materials of the injection layer may include an EIL (electron injection layer), a HIL (hole injection layer) and a CPL (cathode cover layer), which may be in the form of a single layer or dispersed in an electron or hole transport material. The host material may be any suitable host material known in the art. The luminescent color of the OLED is determined by the luminescent energy (optical energy gap) of the EML (luminescent layer) material, and the luminescent energy (optical energy gap) of the luminescent layer material can be tuned by tuning the electronic structure of the emitting divalent platinum complex and / or the host material as described above. The hole transport material in the HTL layer and the electron transport material in the ETL layer may include any suitable hole transporter known in the art. The divalent platinum complex provided in the embodiments of the present invention may exhibit phosphorescence. Phosphorescent OLEDs (i.e., OLEDs with phosphorescent emitters) generally have higher device efficiencies than other OLEDs such as fluorescent OLEDs. Light-emitting devices based on electrophosphorescent emitters are described in Nature, 1998, 395, pp. 151-154, and light-emitting devices based on electrophosphorescent emitters are described in more detail in WO2000 / 070655, which is incorporated herein by reference for its content regarding OLEDs (especially fluorescent OLEDs).

[0171] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A divalent platinum complex, characterized in that Has the following structure: Among them, R1-R 15 are the same or different, and are independently selected from hydrogen, and unsubstituted C1-C30 alkyl.

2. A divalent platinum complex, characterized in that Has the following structure: Among them, R1-R 15 The same or different, independently selected from deuterium, -CDH2, -CD2H, -CD3, -CDR b R c 、-CD2R d , where R b -R d The same or different, each independently selected from unsubstituted C1-C30 alkyl groups.

3. A divalent platinum complex, characterized in that Has the following structure: Among them, R1-R 15 are the same or different and are independently selected from deuterium, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tert-butyl.

4. A divalent platinum complex, characterized in that Has the following structure: Among them, R1-R 15 are the same or different and are independently selected from methyl, deuterated methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tert-butyl.

5. A divalent platinum complex, characterized in that The divalent platinum complex has the structure shown below:

6. A method for preparing the divalent platinum complex according to any one of claims 1 to 4, characterized in that: The steps include: The compound represented by A and the compound represented by B are subjected to coupling reaction to obtain the compound represented by intermediate 1; the compound represented by intermediate 1 and platinum salt are subjected to cyclometallation reaction to obtain the compound represented by formula I; The preparation route of the compound represented by formula I is as follows: Wherein X1 is a halogen, and X2 is a tin group or a boron group.

7. The preparation method according to claim 6, characterized in that: X1 is bromine or chlorine.

8. Use of the divalent platinum complex according to any one of claims 1 to 5 or the divalent platinum complex prepared by the preparation method according to claim 6 in an organic optoelectronic device.

9. The use according to claim 8, characterized in that: The divalent platinum complex serves as a phosphorescent light-emitting material in the organic optoelectronic device.

10. The use according to claim 8 or 9, characterized in that: The divalent platinum complex serves as a yellow phosphorescent light-emitting material in the organic optoelectronic device.

11. An organic optoelectronic device, characterized in that: The organic photoelectric device comprises a positive electrode, a negative electrode and an organic layer disposed between the positive electrode and the negative electrode, wherein the organic layer comprises a light-emitting layer, and the light-emitting layer comprises any one or a combination of at least two of the divalent platinum complexes according to any one of claims 1 to 5.

12. The organic optoelectronic device according to claim 11, characterized in that: The light-emitting layer contains a host material and a doping material, wherein the doping material includes any one or a combination of at least two of the divalent platinum complexes described in any one of claims 1 to 5.

13. The organic optoelectronic device according to claim 11, characterized in that: The organic photoelectric device is a yellow light organic photoelectric device.

14. Use of the divalent platinum complex according to any one of claims 1 to 5 or the divalent platinum complex prepared by the preparation method according to claim 6 in a display device or a lighting device.

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