Divalent platinum complex, preparation method and application thereof, and organic photoelectric device

Abstract

The invention relates to the technical field of luminescent materials, and discloses a bivalent platinum complex, a preparation method and application thereof, and an organic photoelectric device. The divalent platinum complex has a structure as shown in a formula (I), wherein R1, R2, R3 and R4 are the same or different and are independently selected from monatomic substituent groups or polyatomic substituent groups; the monatomic substituent comprises hydrogen atoms and isotope atoms or halogen atoms thereof; the polyatomic substituent groups comprise one or more of substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, alkyl-substituted aryl groups, aryl-substituted aryl groups, cycloalkyl groups, cycloalkenyl groups, heteroaryl groups, alkenyl groups, alkynyl groups, alkoxy groups, aryloxy groups, ester groups, alkoxy carbonyl groups, silyl groups, polymer groups and the substituent groups containing isotope atoms; # imgabs0 #

Description

Technical Field

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

[0002] Organic light-emitting diodes (OLEDs) can be used in the next generation of lighting and display fields due to their surface emission, flexibility, thinness, close to sunlight, low blue light, and no glare hazards. In terms of luminescence, yellow-green 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 yellow light and green light. Therefore, in color science, green-yellow light is formed by filtering out blue light from white light, and is often the complementary auxiliary light color of blue light. In order to produce white emission, a combination of two complementary colors can be simply used, such as blue and yellow. Green-yellow or yellow emission is a key chromaticity component of high-performance white OLED (WOLED). Among all visible colors (blue, green, yellow and red), WOLED is usually composed of three primary colors (RGB), so there is a large gap (up to 100nm) in the white light spectrum because the wavelengths of typical green and red emitters are 520 and 630nm, respectively, resulting in discontinuity of the WOLED spectrum. In other words, the emission in the range of 520 to 630nm is missing, which greatly affects the color rendering index. To address this issue, one approach is to merge yellow-green or yellow emitting materials to form RYGB four-color WOLEDs, and another approach is to directly replace the green emitter or replace the green and red emitting materials with green-yellow materials with the same full width at half maximum (FWHM).

[0003] Yellow-green and bright yellow are important color segments in OLED full-color material display and lighting systems, which can improve the color quality of related light-emitting application devices. The human eye is most sensitive to yellow light and green light. According to the visual function table, the most sensitive band for bright vision of the human eye is 555nm. Therefore, the light in the 555nm band can be used to enhance the brightness of OLED devices, while the light in the 530-540nm band belongs to high-brightness green light, which can be used in light-emitting applications with relatively low color requirements but higher brightness requirements. Summary of the invention

[0004] The purpose of the present invention is to overcome the problem that OLED devices in the prior art lack light-emitting materials that can emit stable and efficient green-yellow and yellow colors, and to provide a divalent platinum complex, a preparation method and application thereof, and an organic optoelectronic device; the present invention introduces a dibenzofuran structure into the ligand structure of the divalent platinum complex, and the divalent platinum complex, as a high-efficiency green-yellow and yellow light-emitting material, has great development potential in the fields of display and lighting.

[0005] In order to achieve the above object, the first aspect of the present invention provides a divalent platinum complex, wherein the divalent platinum complex has a structure shown in formula (I):

[0006]

[0007] Wherein, R1, R2, R3 and R4 are the same or different and are independently selected from single-atom substituents or polyatomic substituents; the single-atom substituents include hydrogen atoms and their isotope atoms or halogen atoms; the polyatomic substituents include substituted or unsubstituted alkyl groups and not tert-butyl groups, substituted or unsubstituted aryl groups, alkyl-substituted aryl groups, aryl-substituted aryl groups, cycloalkyl groups, cycloalkenyl groups, heteroaryl groups, alkenyl groups, alkynyl groups, alkoxy groups, aryloxy groups, ester groups, alkoxycarbonyl groups, silane groups, polymer groups and one or more of the above-mentioned substituents containing isotope atoms.

[0008] The second aspect of the present invention provides a method for preparing a divalent platinum complex, wherein the preparation method comprises:

[0009] (1) performing a fragment coupling reaction of the first monomer represented by formula (a) and the biboronic acid pinacol represented by formula (b) to obtain an intermediate 1 represented by formula (c);

[0010]

[0011] (2) subjecting the intermediate 1 to a SUZUKI coupling reaction with a second monomer represented by formula (d) to obtain a ligand 1 represented by formula (e);

[0012]

[0013] Wherein, x1 and x2 are the same or different and are Br or Cl respectively;

[0014] (3) in the presence of a platinum salt, subjecting the ligand 1 represented by formula (e) to a metal coordination cyclization reaction to obtain a divalent platinum complex represented by formula (I);

[0015]

[0016] Wherein, in formula (a), formula (c), formula (d), formula (e) and formula (I), R1, R2, R3 and R4 have the same definitions as described above.

[0017] The third aspect of the present invention provides a divalent platinum complex prepared by the aforementioned preparation method.

[0018] A fourth aspect of the present invention provides a use of the aforementioned divalent platinum complex in an electroluminescent material and / or a photoluminescent material.

[0019] A fifth aspect of the present invention provides a use of the aforementioned divalent platinum complex in organic optoelectronic devices for lighting and / or display.

[0020] A sixth aspect of the present invention provides an organic optoelectronic device, wherein the organic optoelectronic device comprises a light-emitting layer, and the light-emitting layer comprises the aforementioned divalent platinum complex.

[0021] Through the above technical scheme, the divalent platinum complex provided by the present invention has a chemical structure shown in formula (I), and is a spectrally tunable phosphorescent luminescent material. The present invention introduces a dibenzofuran structure into the ligand structure of the divalent platinum complex, so that the obtained tetradentate ligand coordinated platinum heterocomplex can achieve a spectrum in the range of about 530-560nm. This series of green-yellow platinum complexes can be used to develop yellow light monochromatic devices, and can also be used for white light devices, and applied to lighting or display products. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a luminescence spectrum of complex 1 prepared in Example 1 of the present invention in a thin film;

[0023] Figure 2 is a luminescence spectrum diagram of complex 2 prepared in Example 2 of the present invention in a thin film;

[0024] Figure 3 is a luminescence spectrum of complex 3 prepared in Example 3 of the present invention in a thin film;

[0025] Figure 4 is the UV-visible absorption spectrum of complex 1 prepared in Example 1 of the present invention

[0026] Figure 5 is the complex 1 prepared in Example 1 of the present invention 1 H NMR spectrum;

[0027] Figure 6 is the complex 2 prepared in Example 2 of the present invention 1 H NMR spectrum;

[0028] Figure 7 is the complex 3 prepared in Example 3 of the present invention 1 H NMR spectrum;

[0029] Figure 8 is the mass spectrum of complex 1 prepared in Example 1 of the present invention;

[0030] Fig. 9 is a cross-sectional view of an OLED device in a specific embodiment of the present invention;

[0031] Fig.10: is the emission spectrum of the green-yellow phosphorescent device using complex 1 in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0032] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0033] As mentioned above, the first aspect of the present invention provides a divalent platinum complex, wherein the divalent platinum complex has a structure shown in formula (I):

[0034]

[0035] Wherein, R1, R2, R3 and R4 are the same or different and are independently selected from single-atom substituents or polyatomic substituents; the single-atom substituents include hydrogen atoms and their isotope atoms or halogen atoms; the polyatomic substituents include substituted or unsubstituted alkyl groups and not tert-butyl groups, substituted or unsubstituted aryl groups, alkyl-substituted aryl groups, aryl-substituted aryl groups, cycloalkyl groups, cycloalkenyl groups, heteroaryl groups, alkenyl groups, alkynyl groups, alkoxy groups, aryloxy groups, ester groups, alkoxycarbonyl groups, silane groups, polymer groups and one or more of the above-mentioned substituents containing isotope atoms.

[0036] The inventors of the present invention have found that by introducing a dibenzofuran structure into the ligand of a divalent platinum complex, a green-yellow and yellow phosphorescent luminescent material is provided. As a phosphorescent luminescent material, it can emit green-yellow and phosphorescence, and has good color purity, good stability and high efficiency, and is completely suitable as an organic green-yellow and yellow luminescent body in OLED-related products. In addition, the compounds provided by the embodiments of the present invention are easy to prepare and sublimate and purify, are soluble in general organic solvents, and are suitable for device processes processed by both evaporation and solution methods. The luminescent properties of this type of material have 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 materials provided by the embodiments of the present invention, whose CIE coordinates and luminous efficiency are more in line with the needs of flat panel displays, have great development potential in the fields of display and lighting.

[0037] According to the present invention, the substituted alkyl group is selected from one or more of an aryl-substituted alkyl group, a fluorine-substituted alkyl group and a halogenated alkyl group.

[0038] According to the present invention, the substituted aryl group is selected from an alkyl-substituted aryl group and / or an aryl-substituted aryl group.

[0039] According to the present invention, R1, R2, R3 and R4 are each independently selected from deuterium, -CDH2, -CD2H, -CD3, -CDR5R6, -CD2R5, wherein R5 and R6 are each independently selected from one or more of alkyl, aryl-substituted alkyl, aryl, alkyl-substituted aryl, aryl-substituted aryl, cycloalkyl, cycloalkenyl, heteroaryl, alkenyl, alkynyl, alkoxy, aryloxy, halogenated alkyl, ester, alkoxycarbonyl, amide, silane and polymer groups.

[0040] According to the present invention, the alkyl group is C1-C 30 The alkyl group is preferably C1-C 24 of alkyl.

[0041] According to the present invention, the isotope atoms are deuterium atoms and / or tritium atoms.

[0042] According to the present invention, the halogen atom is selected from one or more of a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

[0043] According to the present invention, R1, R2, R3 and R4 are 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-isopropyl Phenyl, 2-ethylphenyl, 4-methylphenyl, 4-isopropylphenyl, 4-ethylphenyl, 4-tert-butylphenyl, 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 The invention can be selected from the group consisting of 2,3,5-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 and 2,4,6-tricyclopentylphenyl.

[0044] According to the present invention, the divalent platinum complex is selected from at least one of the complexes 1-29 shown below:

[0045]

[0046]

[0047]

[0048] According to the present invention, the divalent platinum complex is a green-yellow phosphorescent material or a yellow phosphorescent material. The divalent platinum complex provided in the embodiments of the present invention has a green-yellow phosphorescent wavelength peak at 530-560 nm.

[0049] The second aspect of the present invention provides a method for preparing a divalent platinum complex, wherein the preparation method comprises:

[0050] (1) performing a fragment coupling reaction of the first monomer represented by formula (a) and the biboronic acid pinacol represented by formula (b) to obtain an intermediate 1 represented by formula (c);

[0051]

[0052] (2) subjecting the intermediate 1 to a SUZUKI coupling reaction with a second monomer represented by formula (d) to obtain a ligand 1 represented by formula (e);

[0053]

[0054] Wherein, x1 and x2 are the same or different and are Br or Cl respectively;

[0055] (3) in the presence of a platinum salt, subjecting the ligand 1 represented by formula (e) to a metal coordination cyclization reaction to obtain a divalent platinum complex represented by formula (I);

[0056]

[0057] Wherein, in formula (a), formula (c), formula (d), formula (e) and formula (I), R1, R2, R3 and R4 have the same definitions as described above.

[0058] According to the present invention, in step (1), the coupling reaction of the fragments further comprises carrying out the reaction in the presence of bis(dibenzylideneacetone)palladium, tricyclohexylphosphine, potassium acetate and 1,4-dioxane.

[0059] According to the present invention, relative to 1-50 mL of 1,4-dioxane, the molar amount of the first monomer represented by formula (a) is 0.5-10 mmol, the molar amount of the biboric acid pinacol represented by formula (b) is 0.1-20 mmol, the molar amount of bis(dibenzylideneacetone)palladium is 0.01-10 mmol, the molar amount of tricyclohexylphosphine is 0.01-10 mmol, and the molar amount of potassium acetate is 0.5-10 mmol.

[0060] According to the present invention, the conditions for the coupling reaction of the fragments include: under N2 atmosphere, at a temperature of 90-180°C, and a time of 12-72h.

[0061] According to the present invention, in step (2), the reaction further comprises being carried out in the presence of tetrakistriphenylphosphine palladium, potassium carbonate and ethylene glycol dimethyl ether.

[0062] According to the present invention, relative to 0.1-50 mL of ethylene glycol dimethyl ether, the molar number of tetrakistriphenylphosphine palladium used is 0.01-10 mmol, and the molar number of potassium carbonate used is 0.1-50 mmol.

[0063] According to the present invention, the conditions of the SUZUKI coupling reaction include: temperature of 30-150° C. and time of 12-72 h.

[0064] According to the present invention, in step (3), the metal coordination cyclization reaction further comprises being carried out in the presence of acetic acid.

[0065] According to the present invention, the platinum salt is potassium chloroplatinite.

[0066] According to the present invention, the molar amount of the ligand 1 represented by formula (e) is 0.03-30 mmol, and the molar amount of potassium chloroplatinite is 0.03-30 mmol relative to 5-200 mL of acetic acid.

[0067] According to the present invention, the conditions of the metal coordination cyclization reaction include: in a N2 atmosphere, first stirring at a temperature of 20-50°C for 12-72h; then heating to 100-180°C for 24-72h.

[0068] According to a preferred embodiment of the present invention, the complex provided by the present invention can be synthesized by the following general route, the specific steps of which are the coupling reaction of the fragments and the metal coordination cyclization reaction:

[0069]

[0070] The third aspect of the present invention provides a divalent platinum complex prepared by the aforementioned preparation method.

[0071] A fourth aspect of the present invention provides a use of the aforementioned divalent platinum complex in an electroluminescent material and / or a photoluminescent material.

[0072] According to the present invention, the divalent platinum complex is used as a green-yellow phosphorescent material or a yellow phosphorescent material.

[0073] A fifth aspect of the present invention provides a use of the aforementioned divalent platinum complex in organic optoelectronic devices for lighting and / or display.

[0074] A sixth aspect of the present invention provides an organic optoelectronic device, wherein the organic optoelectronic device comprises a light-emitting layer, and the light-emitting layer comprises the aforementioned divalent platinum complex.

[0075] According to the present invention, the organic optoelectronic device further comprises a substrate, an anode layer, a hole transport layer, an electron transport layer and a metal cathode layer, wherein the electron transport layer and / or the hole transport layer comprises the aforementioned divalent platinum complex.

[0076] According to the present invention, the divalent platinum complex is the light-emitting material, host material or guest material in the light-emitting layer.

[0077] The present invention will be described in detail below through examples.

[0078] In the following examples and comparative examples:

[0079] (1) Nuclear magnetic resonance spectroscopy analysis: in CDCl3 or DMSO-d6 solution, recorded by Varian liquid nuclear magnetic resonance instrument 1 HNMR (hydrogen nuclear magnetic resonance) and 13 C NMR spectra were recorded at 300 MHz, 400 MHz 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.

[0080] (2) Mass spectrometry analysis: Some compounds were tested by electrospray ionization mass spectrometry (ESI-MS) using a Waters Aquity Qda ultrahigh pressure liquid chromatography-mass spectrometry instrument, or by high-resolution mass spectrometry using a matrix-assisted ionization time-of-flight mass spectrometer (MALDI-TOF-MS).

[0081] (3) Material purification: The final product, the platinum complex, was separated by column chromatography and preparative HPLC, and then purified by ultra-high vacuum (10 -4 ~10 -5 Pa) sublimation purification equipment is used to perform sublimation purification to the purity requirement for device production.

[0082] (4) High performance liquid chromatography analysis: using methanol / water (1 / 9) as the mobile phase, the purity of the platinum complex sample was analyzed.

[0083] (5) Cyclic voltammetry curve test and energy level calculation: The test uses a three-electrode system, with a platinum column as the working electrode, a platinum wire as the counter electrode, and silver / silver chloride (Ag / AgCl) as the reference electrode. Under a nitrogen atmosphere, the sample was tested using N,N-dimethylformamide containing 0.1M tetrabutylammonium hexafluorophosphate as the solvent, ferrocene as the internal standard, and a scan rate of 100mV / s. According to formulas 5-1, 5-2 and the CV test results, the highest occupied orbital (HOMO) and lowest unoccupied orbital (LUMO) energy levels of the platinum complex molecule can be calculated. Since the measured potential of ferrocene relative to the reference electrode in DMF solution is not a fixed value, but has slight differences in different platinum complex solutions, we choose the ferrocene redox potential measured in the test for calculation.

[0084] HOMO=-[E ox -E Fc / Fc+ox +4.8]eV 5-1

[0085] LUMO=-[E red -E Fc / Fc+red +4.8]eV 5-2

[0086] Where: E ox 、E red are the oxidation peak onset potential and reduction peak onset potential of the sample, E Fc / Fc+ox 、E Fc / Fc+red are the onset potential of the oxidation peak and the reduction peak of ferrocene, respectively, and 4.8 is the vacuum energy level of ferrocene.

[0087] (6) UV-Vis absorption spectrum test: The absorption spectrum of the platinum complex in dichloromethane solution at room temperature was tested with a scanning range of 250 to 500 nm and an interval of 1 nm.

[0088] (7) Steady-state spectrum test: The room temperature dichloromethane solution spectrum of the platinum complex, the 77K 2-methyltetrahydrofuran luminescence spectrum / excitation spectrum, and the 5wt% doped polymethyl methacrylate (PMMA) film spectrum were tested. The dichloromethane solution spectrum was tested after the solvent was fully bubbling with nitrogen; the polymer-doped film was prepared by spin coating in a glove box using chloroform as the solvent and a quartz sheet as the film carrier; the film sample was tested in a glove box or a vacuum chamber to reduce the quenching effect of oxygen on the luminescence of the complex. In addition, the photoluminescence quantum yield (PLQY) of the platinum complex solution and film was tested using an integrating sphere.

[0089] (8) Transient spectrum and phosphorescence lifetime test: The Fluorolog-3 full spectrum optical platform was used to perform time-resolved spectrum test and luminescence lifetime half-life test on the room temperature dichloromethane solution of the platinum complex, and lifetime test on the 5wt% doped PMMA film. All tests were carried out under nitrogen or vacuum conditions.

[0090] Example 1

[0091] Preparation of complex 1.

[0092] (1) Synthesis of intermediate 1:

[0093]

[0094] 2-((4-chlorodibenzo[b,d]furan-2-yl)oxy)-9-(pyridin-2-yl)-9H-carbazole (760 mg, 1.7 mmol), biboronic acid pinacol ester (1.27 g, 5 mmol), bis(dibenzylideneacetone) palladium (46 mg, 0.05 mmol), tricyclohexylphosphine (34 mg, 0.12 mmol), potassium acetate (245 mg, 2.5 mmol) and 1,4-dioxane (8 mL) were added to a 15 mL sealed tube with a magnetic rotor. The resulting mixture was heated to 120°C and stirred for 24 hours after nitrogen bubbling for 10 minutes. Cool to room temperature, add water to quench the reaction, extract with ethyl acetate, combine the organic phases, wash with an appropriate amount of saturated sodium chloride aqueous solution, and dry over anhydrous sodium sulfate. The solvent was removed by distillation under reduced pressure, and the resulting crude product was separated and purified by silica gel column chromatography with petroleum ether:ethyl acetate = 10:1 as the eluent to obtain a white solid with a yield of 50%.

[0095] (2) Synthesis of ligand 1:

[0096]

[0097] Add intermediate 1 (350 mg, 0.63 mmol), 2-bromopyridine (150 mg, 0.95 mmol), tetrakistriphenylphosphine palladium (22 mg, 0.02 mmol), potassium carbonate (174 mg, 1.26 mmol), ethylene glycol dimethyl ether (0.63 ml) and H2O (0.63 ml) to a 75 mL sealed tube with a magnetic rotor. After nitrogen bubbling for 10 minutes, heat to 120 ° C and stir for 24 hours. Cool to room temperature, dilute with water, extract with ethyl acetate, combine the organic phases, wash with an appropriate amount of saturated sodium chloride aqueous solution and dry with anhydrous sodium sulfate. Remove the solvent by distillation under reduced pressure, and separate and purify the crude product by silica gel column chromatography. The eluent is petroleum ether: ethyl acetate = 5:1 to obtain a white solid product with a yield of 87%.

[0098] (3) Synthesis of Complex 1:

[0099]

[0100] Add ligand 1 (260 mg, 0.52 mmol), potassium chloroplatinate (237 mg, 0.57 mmol) and acetic acid (52 mL) to a 350 mL sealed tube with a magnetic rotor. After nitrogen bubbling for 10 minutes, the resulting mixture was stirred at 30 ° C for 24 hours and then heated to 120 ° C for 24 hours. Cool to room temperature, add water to quench the reaction, extract with dichloromethane, combine the organic phases, wash with an appropriate amount of saturated sodium chloride aqueous solution, and dry with anhydrous sodium sulfate. The solvent was removed by distillation under reduced pressure, and the resulting crude product was separated and purified by silica gel column chromatography, with the eluent being dichloromethane: petroleum ether = 1:1, to obtain a yellow solid with a yield of 80%.

[0101] Figure 5 is the complex 1 of the present invention 1 H NMR spectrum: 1 H NMR(400MHz,)δ9.14(dd,J=5.8,1.4Hz,1H),8.96-8.82(m,2H),8.42-8.30(m,1H),8.31-8.14(m,4H),8.10(d,J=8.1Hz,1H),7.95 (s,1H),7.90(d,J=8.3Hz,1H),7.81(d,J=8.1Hz,1H),7.70(ddd,J=7.2,5.7,1.2Hz,1H),7.60-7.38(m,5H),7.27(d,J=8.2Hz,1H).

[0102] in addition, Figure 8 is the mass spectrum of complex 1 in a specific embodiment of the present invention; Figure 8 It can be seen that: MS (ESI): 697.0 [M + H] + .

[0103] Example 2

[0104] Preparation of complex 2.

[0105] (1) Intermediate 1 was prepared by the same synthetic method as in Example 1.

[0106] (2) Synthesis of ligand 2:

[0107]

[0108] Add intermediate 1 (55 mg, 0.1 mmol), 2-bromo-4-(tert-butyl)pyridine (32 mg, 0.15 mmol), tetrakistriphenylphosphine palladium (4 mg, 0.03 mmol), potassium carbonate (28 mg, 0.2 mmol), ethylene glycol dimethyl ether (0.1 ml) and H2O (0.1 ml) to a 15 mL sealed tube with a magnetic rotor. The resulting mixture was heated to 120 °C and stirred for 24 hours after nitrogen bubbling for 10 minutes. Cool to room temperature, dilute with water, extract with ethyl acetate, combine the organic phases, wash with an appropriate amount of saturated sodium chloride aqueous solution and dry with anhydrous sodium sulfate. Remove the solvent by distillation under reduced pressure, and separate and purify the resulting crude product by silica gel column chromatography. The eluent is petroleum ether: ethyl acetate = 15:1 to obtain a white solid product with a yield of 78%.

[0109] (3) Synthesis of Complex 2:

[0110]

[0111] Add ligand 1 (35 mg, 0.06 mmol), potassium chloroplatinate (25 mg, 0.06 mmol) and acetic acid (6 mL) to a 350 mL sealed tube with a magnetic rotor. After nitrogen bubbling for 10 minutes, the resulting mixture was stirred at 30 ° C for 24 hours and then heated to 120 ° C for 24 hours. Cool to room temperature, add water to quench the reaction, extract with dichloromethane, combine the organic phases, wash with an appropriate amount of saturated sodium chloride aqueous solution, and then dry with anhydrous sodium sulfate. The solvent was removed by distillation under reduced pressure, and the resulting crude product was separated and purified by silica gel column chromatography, with the eluent being dichloromethane: petroleum ether = 1:1, to obtain a yellow solid with a yield of 74%.

[0112] Figure 6 is the complex 2 of the present invention 1 H NMR spectrum: 1 H NMR (400MHz, DMSO-d6) δ9.14(d,J=5.6Hz.1H),8.93(d,J=2.0Hz,1H),8.77(d,J=6.0Hz,1H),8.30-8.14(m,4H),8.10(d,J=8.1Hz,1H),7.9 3(s,1H),7.89(d,J=8.3Hz,1H),7.82(d,J=8.2Hz,1H),7.74(dd,J=6.0,2.1Hz,1H),7.57-7.37(m,5H),7.26(d,J=8.2Hz,1H),1.50(s,9H).

[0113] Example 3

[0114] Preparation of complex 3.

[0115] (1) Intermediate 1 was prepared by the same synthetic method as in Example 1.

[0116] (2) Synthesis of ligand 3:

[0117]

[0118] Add intermediate 1 (166 mg, 0.3 mmol), 2-bromo-4-(phenyl)pyridine (85 mg, 0.45 mmol), tetrakistriphenylphosphine palladium (12 mg, 0.009 mmol), potassium carbonate (83 mg, 0.6 mmol), ethylene glycol dimethyl ether (0.3 ml) and H2O (0.3 ml) to a 15 mL sealed tube with a magnetic rotor. The resulting mixture was heated to 120 °C and stirred for 24 hours after nitrogen bubbling for 10 minutes. Cool to room temperature, dilute with water, extract with ethyl acetate, combine the organic phases, wash with an appropriate amount of saturated sodium chloride aqueous solution and dry with anhydrous sodium sulfate. The solvent was removed by distillation under reduced pressure, and the resulting crude product was separated and purified by silica gel column chromatography, with the eluent being petroleum ether: ethyl acetate = 15:1, to obtain a white solid product with a yield of 63%.

[0119] (3) Synthesis of Complex 3:

[0120]

[0121] Add ligand 1 (300 mg, 0.51 mmol), potassium chloroplatinate (232 mg, 0.56 mmol) and acetic acid (51 mL) to a 350 mL sealed tube with a magnetic rotor. After nitrogen bubbling for 10 minutes, the resulting mixture was stirred at 30 ° C for 24 hours and then heated to 120 ° C for 24 hours. Cool to room temperature, add water to quench the reaction, extract with dichloromethane, combine the organic phases, wash with an appropriate amount of saturated sodium chloride aqueous solution, and then dry with anhydrous sodium sulfate. The solvent was removed by distillation under reduced pressure, and the resulting crude product was separated and purified by silica gel column chromatography, with the eluent being dichloromethane: petroleum ether = 1:1, to obtain a yellow solid with a yield of 70%.

[0122] Figure 7 is the complex 3 of the present invention 1 H NMR spectrum: 1H NMR (400MHz, DMSO-d6) δ9.21(d,J=5.8Hz,1H),9.13(t,J=2.9Hz,1H),8.91(d,J=6.0Hz,1H),8.32-8.15(m,4H),8.15-7.98(m ,4H),7.95(s,1H),7.88(dd,J=14.4,8.2Hz,2H),7.67(ddd,J=14.1,8.6,7.1Hz,4H),7.59-7.37(m,5H),7.28(d,J=8.2Hz,1H)

[0123] Application Example 1

[0124] Embodiments 1-3 respectively provide an organic photoelectric device, which includes a light-emitting layer, and the light-emitting layer contains the above-mentioned divalent platinum complex.

[0125] The method for preparing the organic photoelectric device is as follows:

[0126] The crucible containing OLED organic material and the crucible containing metal aluminum particles are placed on the positions of the organic evaporation source and the inorganic evaporation source in turn. The cavity is closed, and the initial vacuum and high vacuum steps are performed to make the vacuum degree of evaporation inside the OLED evaporation equipment reach 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 quickly heated, and the baffle above the evaporation source is opened until the evaporation source of the material has organic material running out, and the crystal oscillator detector detects the evaporation rate, and then slowly heats up, the temperature rise is 3°C, until the evaporation rate stabilizes at 1A / second, open the baffle directly below the mask plate, and perform OLED film formation. When the computer observes that the organic film on the ITO substrate reaches the preset film thickness, close the mask plate baffle and the baffle directly above the evaporation source, and close the evaporation source heater of the organic material. The evaporation process of other organic materials and cathode metal materials is as described above. The package is encapsulated using UV epoxy resin for light curing.

[0127] The cross-sectional view of the OLED device in Example 1-3 is as follows: Fig. 9 It is shown that platinum complexes 1, 2 and 3 are doped into the main material as light-emitting materials to prepare OLED devices, with a doping amount of 5%. ITO is the anode (Anode) of the OLED device, and Al is the cathode (Cathode) of the OLED device.

[0128] The device structure is: ITO / HIL (10nm) / HTL (140nm) / EML (25nm) / ETL (35nm) / EIL (10nm) / Al. HIL, HTL, EML, ETL, and EIL are the functional layer structures that constitute the OLED device, corresponding to the hole injection layer, hole transport layer, light-emitting layer, electron transport layer, and electron injection layer, respectively. They can be single-layer structures, double-layer or multi-layer structures to optimize the device's light-emitting effect. HI can be but not limited to HATCN, Re2O3, etc.; HTL can be TAPC, NPD, TCTA, and the EML layer is a light-emitting layer complex: main material = 5%: 95% main material can be CBP, mCBP, 2,6mCPy, etc.; ETL can be TmPyPb, TPBi, DPPS, etc.; EIL layer can be LiQ, LiF, etc.

[0129] 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);

[0130] Re2O3 (Chinese name: molybdenum trioxide, English name: Molybdenum (VI) oxide);

[0131] TAPC (Chinese name: 4,4′-cyclohexylbis[N,N-di(4-methylphenyl)aniline], English name: 4,4′-cyclohexylidenebis[N,N-bis(p-tolyl)aniline];

[0132] 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)

[0133] TCTA (Chinese name: 4,4′,4”-Tris(carbazol-9-yl)triphenylamine, English name: 4,4′,4”-Tris(carbazol-9-yl)triphenylamine)

[0134] CBP (Chinese name: 4,4'-di(9-carbazolyl)biphenyl, English name: 4,4'-Bis(9-carbazolyl)-1,1'-biphenyl);

[0135] 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)

[0136] 2,6mCPy (Chinese name: 2,6-di(9-carbazol-9-yl)pyridine, English name: 2,6-Di(9H-carbazol-9-yl)pyridine);

[0137] 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)

[0138] 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);

[0139] DPPS (Chinese name: Diphenylbis[4-(pyridin-3-yl)phenyl]silane, English name: Diphenylbis(4-(pyridin-3-yl)phenyl)silane)

[0140] LiF (Chinese name: lithium fluoride, English name: Lithium fluoride)

[0141] LiQ (Chinese name: 8-Hydroxyquinolinolato-lithium, English name: 8-Hydroxyquinolinolato-lithium)

[0142] Test Example 1

[0143] Performance Testing

[0144] The compounds of the synthesis examples and the comparative compounds were 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:

[0145] (1) Testing of the luminous properties of electroluminescent materials: CIE is based on the chromaticity coordinate parameters of the International Commission on Illumination standard.

[0146] (2) Photoelectric energy level test of electroluminescent materials: band gap value of the material (E g), the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO) values ​​were measured by cyclic voltammetry (CV). The entire test process was carried out on a CHI600D electrochemical workstation (Shanghai Chenhua Instrument Co., Ltd.) in a glove box (Lab2000, Etelux). A three-electrode system was formed with a Pt column as the working electrode, Ag / AgCl as the reference electrode, and a Pt wire as the auxiliary electrode. The medium used in the test process was a 0.1M tetrabutylammonium hexafluorophosphate (Bu4NPF6) dimethylformamide (DMF) solution, and the measured potentials were all based on the added ferrocene (Fc) as the internal standard. In the table below, λ is the peak wavelength of the divalent platinum complex dissolved in dichloromethane, FWHM is its half-peak width, and the triplet photon energy (ET1) of the material is given by the formula 1240 / λ 0→1 Calculated from (λ 0→1 is the first vibration peak under 77K conditions), and its unit is electron volt (eV).

[0147] The above test results are shown in Table 1 and Table 2.

[0148] The following tests were performed on the organic optoelectronic devices of the embodiments and comparative examples:

[0149] (3) IVL performance test of organic optoelectronic devices. The IVL equipment was tested using Mc Science M6100.

[0150] (4) Energy level test of organic optoelectronic device: the same method as in performance test (1).

[0151] (5) Light emitting performance test of organic optoelectronic device: same as the method in performance test (2).

[0152] The above test results are shown in Table 3.

[0153] Table 1 Luminescence properties of the complexes

[0154]

[0155] in: a Dichloromethane solution, b PMMA film

[0156] Table 1 shows the relevant data of the luminescent properties of the complexes. The peak wavelengths of the complexes 1-3 prepared in the present invention in the solution are between 530 and 560 nm, the half-peak widths are all around 67 to 74 nm, and the photoluminescence efficiency is in the range of 77 to 94%, indicating that the divalent platinum complex having the general formula I structure is a highly efficient green-yellow and yellow phosphorescent luminescent material.

[0157] In addition, the relevant drawings are described as follows:

[0158] Figure 1-3The luminescence spectra of divalent platinum complex 1, complex 2, and complex 3 in the film are shown respectively; under 380nm ultraviolet light excitation, the luminescence wavelength in PMMA is 529-547nm, and the wavelengths of the complexes are all in the green-yellow and yellow phosphorescence regions, indicating that the complex is an excellent green-yellow and yellow luminescent material.

[0159] Figure 4 The UV-visible absorption spectrum of the above-mentioned divalent platinum complex 1 in DCM solution is shown. According to the absorption spectrum, we can know that the strong absorption band at 270nm is attributed to the spin-allowed absorption of the aromatic ring in the ligand. 1 LC( 1 π-π*) transition, the absorption around 300nm mainly comes from C-pyridine unit, dibenzofuran unit and carbazole group 1 LLCT( 1 π-π*) transition, while the absorption near 400nm is mainly due to d Pt →π py * Charge transfer ( 1 MLCT).

[0160] Table 2 Energy level data of complexes

[0161] Complex <![CDATA[E HOMO (eV)]]> <![CDATA[E LUMO (eV)]]> <![CDATA[E g (eV)]]> λ(nm) <![CDATA[E T1 (eV)]]> Complex 1 -5.13 -2.56 2.57 540 2.35 Complex 2 -5.27 -2.48 2.79 530 2.10 Complex 3 -5.08 -2.69 2.39 560 2.26

[0162] Table 2 shows the energy level data of the complex. From the data in Table 2, it can be seen that the triplet energy of the divalent platinum complex of complex 2 is 2.10 eV, which is mainly related to the parent core structure.

[0163] Table 3 Luminescence performance of organic optoelectronic devices

[0164]

[0165] Table 3 shows the optical properties of phosphorescent devices prepared by complex 1, complex 2 and complex 3. The peak wavelengths of the devices involved in Examples 1-3 are 535nm, 533nm and 559nm respectively. Complex 1 and complex 2 emit yellowish green phosphorescence. The half-peak width of Example 3 is 85nm, which is in the green-yellow (bright yellow) light range. The device has a peak wavelength of 1000 cd·m -2 Brightness Highest Current Efficiency Energy Efficiency (PE) is 49.6lm·W -1 , the highest current efficiency (CE) is 53.6cd·A -1 , and the external quantum efficiency (EQE) reaches 17.8%, which is a high-efficiency light-emitting device.

[0166] In addition, the relevant drawings are described as follows:

[0167] Organic photoluminescent device cross section Fig. 9As shown, when the divalent platinum complex is used as a doping material in an OLED device, a yellow phosphorescent device is prepared by evaporation. The device structure is as shown in Fig. 9 ITO / HIL(10nm) / HTL(140nm) / EML(25nm) / ETL(35nm) / EIL(10nm) / Al

[0168] The electroluminescence spectrum of complex 1 is shown in Fig.10 As shown, the horizontal axis is the wavelength and the vertical axis is the normalized intensity.

[0169] The present invention uses an exemplary embodiment to illustrate that the general structural formula (I) can be used as a green-yellow and yellow phosphorescent doping material, and a single-doped yellow-green, 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 near the divalent platinum complex and 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 by the embodiments of the present invention can exhibit phosphorescence. Phosphorescent OLEDs (ie, OLEDs with phosphorescent emitters) generally have higher device efficiencies than other OLEDs such as fluorescent OLEDs.

[0170] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A divalent platinum complex, characterized in that The divalent platinum complex has a structure shown in formula (I): Wherein, R1, R2, R3 and R4 are the same or different and are independently selected from single-atom substituents or polyatomic substituents; the single-atom substituents include hydrogen atoms and their isotope atoms or halogen atoms; the polyatomic substituents include substituted or unsubstituted alkyl groups and not tert-butyl groups, substituted or unsubstituted aryl groups, alkyl-substituted aryl groups, aryl-substituted aryl groups, cycloalkyl groups, cycloalkenyl groups, heteroaryl groups, alkenyl groups, alkynyl groups, alkoxy groups, aryloxy groups, ester groups, alkoxycarbonyl groups, silane groups, polymer groups and one or more of the above-mentioned substituents containing isotope atoms.

2. The divalent platinum complex according to claim 1, wherein The substituted alkyl group is selected from one or more of an aryl-substituted alkyl group, a fluorine-substituted alkyl group and a haloalkyl group; And / or, the substituted aryl group is an alkyl-substituted aryl group and / or an aryl-substituted aryl group.

3. The divalent platinum complex according to claim 1, wherein R1, R2, R3 and R4 are each independently selected from deuterium, -CDH2, -CD2H, -CD3, -CDR5R6, -CD2R5, wherein R5 and R6 are each independently selected from one or more of alkyl, aryl-substituted alkyl, aryl, alkyl-substituted aryl, aryl-substituted aryl, cycloalkyl, cycloalkenyl, heteroaryl, alkenyl, alkynyl, alkoxy, aryloxy, haloalkyl, ester, alkoxycarbonyl, amide, silane and polymer groups.

4. The divalent platinum complex according to any one of claims 1 to 3, wherein The alkyl group is C1-C 30 The alkyl group is preferably C1-C 24 The alkyl group; and / or, the isotope atoms are selected from deuterium atoms and / or tritium atoms; And / or, the halogen atom is selected from one or more of a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

5. The divalent platinum complex according to any one of claims 1 to 4, wherein R1, R2, R3 and R4 are 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, 4-methylphenyl, 4-isopropylphenyl, 4-ethylphenyl, 4-tert-butylphenyl, 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 , 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 and 2,4,6-tricyclopentylphenyl.

6. The divalent platinum complex according to any one of claims 1 to 5, wherein The divalent platinum complex is selected from at least one of the complexes 1-29 shown below:

7. A method for preparing a divalent platinum complex, characterized in that: The preparation method comprises: (1) performing a fragment coupling reaction of the first monomer represented by formula (a) and the biboronic acid pinacol represented by formula (b) to obtain an intermediate 1 represented by formula (c); (2) subjecting the intermediate 1 to a SUZUKI coupling reaction with a second monomer represented by formula (d) to obtain a ligand 1 represented by formula (e); Wherein, x1 and x2 are the same or different and are Br or Cl respectively; (3) in the presence of a platinum salt, subjecting the ligand 1 represented by formula (e) to a metal coordination cyclization reaction to obtain a divalent platinum complex represented by formula (I); Wherein, in formula (a), formula (c), formula (d), formula (e) and formula (I), R1, R2, R3 and R4 have the same definition as described in any one of claims 1 to 6.

8. The preparation method according to claim 7, wherein: In step (1), the coupling reaction of the fragments further comprises carrying out the reaction in the presence of bis(dibenzylideneacetone)palladium, tricyclohexylphosphine, potassium acetate and 1,4-dioxane; and / or, relative to 1-50 mL of 1,4-dioxane, the molar amount of the first monomer represented by formula (a) is 0.5-10 mmol, the molar amount of the pinacol diboron represented by formula (b) is 0.1-20 mmol, the molar amount of bis(dibenzylideneacetone)palladium is 0.01-10 mmol, the molar amount of tricyclohexylphosphine is 0.01-10 mmol, and the molar amount of potassium acetate is 0.5-10 mmol; And / or, the coupling reaction conditions of the fragments include: under N2 atmosphere, at a temperature of 90-180°C, and a time of 12-72h.

9. The preparation method according to claim 7, wherein: In step (2), the reaction further comprises being carried out in the presence of tetrakistriphenylphosphine palladium, potassium carbonate and ethylene glycol dimethyl ether; and / or, relative to 0.1-50 mL of ethylene glycol dimethyl ether, the molar amount of tetrakistriphenylphosphine palladium used is 0.01-10 mmol, and the molar amount of potassium carbonate used is 0.1-50 mmol; And / or, the conditions of the SUZUKI coupling reaction include: temperature of 30-150° C. and time of 12-72 h.

10. The preparation method according to claim 7, wherein: In step (3), the metal coordination cyclization reaction further comprises being carried out in the presence of acetic acid; And / or, the platinum salt comprises potassium chloroplatinite; and / or, relative to 5-200 mL of acetic acid, the molar amount of the ligand 1 represented by formula (e) is 0.03-30 mmol, and the molar amount of potassium chloroplatinite is 0.03-30 mmol; And / or, the conditions of the metal coordination cyclization reaction include: first stirring at a temperature of 20-50° C. for 12-72 h under a N2 atmosphere; Then raise the temperature to 100-180℃ for 24-72h.

11. A divalent platinum complex prepared by the preparation method according to any one of claims 7 to 10.

12. Use of the divalent platinum complex according to any one of claims 1 to 6 and 11 in electroluminescent materials and / or photoluminescent materials.

13. The use according to claim 12, wherein: The divalent platinum complex is used as a green-yellow phosphorescent material or a yellow phosphorescent material.

14. Use of the divalent platinum complex according to any one of claims 1 to 6 and 11 in organic optoelectronic devices for lighting and / or display.

15. An organic optoelectronic device, characterized in that: The organic optoelectronic device comprises a light-emitting layer, wherein the light-emitting layer comprises the divalent platinum complex according to any one of claims 1 to 6 and 11.

16. The organic optoelectronic device according to claim 15, wherein: The organic optoelectronic device further comprises a substrate, an anode layer, a hole transport layer, an electron transport layer and a metal cathode layer, wherein the electron transport layer and / or the hole transport layer comprises the divalent platinum complex according to any one of claims 1 to 6 and 11.

17. The organic optoelectronic device according to claim 15 or 16, wherein: The divalent platinum complex is a light-emitting material, a host material or a guest material in the light-emitting layer.

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