Heterocyclic-modified platinum complexes containing ONCN tetradentate ligands

Abstract

The present invention relates to a heterocyclic modified platinum complex containing an ONCN tetradentate ligand, having a structure shown in chemical formula (I), and the complex is applied in an organic light-emitting diode, has a lower driving voltage and a higher luminous efficiency, and can significantly improve the service life of the device, and has the potential to be applied in the field of organic electroluminescent devices. The present invention also provides an organic electrophotoelectric device, comprising a cathode, an anode and an organic layer, wherein the organic layer is one or more layers of a hole injection layer, a hole transport layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer, and at least one layer of the organic layer contains a compound in structural formula (I).

Description

Technical Field

[0001] The invention relates to the field of luminescent materials, and in particular to a heterocyclic platinum complex and application thereof in an organic light emitting diode. Background Art

[0002] Phosphorescent organic light-emitting diodes (OLEDs) have attracted great attention from academia and industry in the past few decades due to their advantages such as ultra-light and ultra-thin, low power consumption, autonomous luminescence, wide operating temperature range, wide color gamut, wide viewing angle, fast response speed, and easier flexible display. For phosphorescent OLED molecules, the coordination of transition metal centers and organic frameworks provides huge synthetic diversity. The changes in the properties of metal centers, the bonding mode of metal complexation, and the ligand design constitute a representative building block class. The rational design of multifunctional metal complexes can not only regulate electronic absorption, luminescence, and excited state redox properties, but also realize diversified optical functional properties. It is a new generation of display and solid-state lighting technology with great application prospects.

[0003] Since the discovery of phosphorescent OLEDs in 1998, phosphorescent OLEDs have greatly promoted the commercialization of OLEDs because they can efficiently utilize singlet and triplet excitons to emit light, theoretically achieving 100% internal quantum efficiency compared to traditional fluorescence. The vast majority of metal complexes have been developed from hexadentate complexes with Ir(III) as the metal core. The latest development of metal complexes in the past decade has enabled square planar Pt(II) and Pd(II) complexes to even surpass the performance of Ir complexes in many aspects. In particular, the development of N-heterocyclic carbene emitters and tetradentate cyclometallated Pt and Pd complexes has significantly improved the light emission efficiency and reduced the exciton radiation lifetime, making them more competitive with Ir complexes. In addition, their unique and diverse molecular designs can obtain narrower emission spectra and can fine-tune various photophysical properties such as PL, HOMO, LUMO, CIE and T3 levels with different substituents. At the same time, although iridium complexes are currently the most common light-emitting materials in OLEDs, iridium metal is the element with the lowest relative content in the earth's crust. Relatively speaking, platinum and palladium, which are also heavy metals, have much higher reserves in the earth's crust.

[0004] Bidentate and tridentate ligands containing nitrogen atoms or carbon donors, such as C^N, C^N^N and N^C^N systems, are often used to develop phosphorescent platinum complexes. When using these ligands to synthesize complexes with d8 electronic configuration, the usual choice is a "tridentate ligand plus a monodentate ligand" or "two bidentate ligands". Due to the chelating effect of the multidentate ligand, the metal ion is stabilized at the center of the complex in the ONCN-based Pt(II) tetradentate complex. The demetallation of the complex can generally be suppressed, so this type of complex will have high thermal stability and relatively high chemical stability; the dx2-y2 orbital energy level of the metal ion is increased due to the presence of the strong field ligand, thereby weakening the molecular deformation of the excited state, which is expected to improve the luminescence quantum efficiency; the covalent metal-carbon bond increases the mixing of the metal d orbital and the ligand orbital, thereby also improving the stability of the compound. The mixing of metal d orbitals and ligand orbitals can enhance the influence of the metal center on the excited state of the ligand itself and strengthen the spin-orbit coupling effect, thereby increasing the quantum yield of the triplet state and promoting efficient phosphorescence radiation.

[0005] Although ONCN-based Pt(II) tetradentate complexes have many advantages, Pt metal complex luminescent materials are already very close to industrial application. However, their performance, such as the luminous efficiency and service life of OLED devices, still needs to be further improved to meet the needs of commercial mass production. Summary of the invention

[0006] Based on the needs in the above-mentioned field, the present invention provides a heterocyclic modified platinum complex containing an ONCN tetradentate ligand, the modification of the nitrogen-containing heterocyclic structure of which can significantly improve its luminous intensity and light extraction efficiency in specific optical components.

[0007] A heterocyclic modified platinum complex containing an ONCN tetradentate ligand, the structure of which is shown in formula (I),

[0008]

[0009] in:

[0010] R 1 To R 15 Each is independently selected from the group consisting of hydrogen, deuterium, halogen, amine, carbonyl, carboxyl, sulfanyl, cyano, sulfonyl, phosphino, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms;

[0011] Ar is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms;

[0012] The heteroatom in the heteroaryl group is one or more of N, S, and O;

[0013] The substitution is substitution with halogen, amine, cyano, C1-C4 alkyl or fluorinated C1-C4 alkyl.

[0014] Preferably, R 1 To R 15 Each is independently selected from the group consisting of hydrogen, deuterium, halogen, amine, sulfanyl, cyano, substituted or unsubstituted alkyl having 1 to 6 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 6 ring carbon atoms, substituted or unsubstituted alkenyl having 2 to 6 carbon atoms, substituted or unsubstituted alkoxy having 1 to 6 carbon atoms;

[0015] Ar is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms;

[0016] The substitution is substitution with halogen, amine, cyano, C1-C4 alkyl or fluorinated C1-C4 alkyl.

[0017] Preferably, R 1 To R 15 Each is independently selected from: hydrogen, deuterium, halogen, cyano, C1-C4 alkyl, substituted or unsubstituted cycloalkyl having 3-6 ring carbon atoms;

[0018] Ar is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms;

[0019] The substitution is substitution with halogen, amine, cyano, C1-C4 alkyl or fluorinated C1-C4 alkyl.

[0020] Preferably, R 1 To R 15 Each is independently selected from the group consisting of hydrogen, deuterium, cyano, methyl, isopropyl, isobutyl, tert-butyl, substituted or unsubstituted cyclopentyl, substituted or unsubstituted cyclohexyl;

[0021] Ar is selected from substituted or unsubstituted phenyl, substituted or unsubstituted pyridyl, substituted or unsubstituted pyrazinyl, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted imidazolyl, substituted or unsubstituted carbazolyl;

[0022] The substitution is substitution with halogen, cyano, C1-C4 alkyl or fluorinated C1-C4 alkyl.

[0023] Preferably, in the general formula (I), R 1 To R 15Each is independently selected from: hydrogen, deuterium, methyl, tert-butyl, cyano;

[0024] Ar is selected from substituted or unsubstituted phenyl, substituted or unsubstituted pyridyl, substituted or unsubstituted imidazolyl, substituted or unsubstituted carbazolyl;

[0025] The substitution is substitution with halogen, amine, cyano, C1-C4 alkyl or fluorinated C1-C4 alkyl.

[0026] More preferably, in the general formula (I), R 1 To R 15 R 13 is tert-butyl, and the rest are hydrogen;

[0027] Ar is selected from a substituted or unsubstituted phenyl group, a substituted or unsubstituted pyridyl group, or a substituted or unsubstituted carbazolyl group.

[0028] Examples of platinum metal complexes according to the present invention are listed below, but are not limited to the structures listed:

[0029]

[0030]

[0031]

[0032] The precursor of the above metal complex, i.e. the ligand, has the following structural formula:

[0033]

[0034] Application of the platinum complex in organic light emitting diodes, organic thin film transistors, organic photovoltaic devices, light emitting electrochemical cells or chemical sensors.

[0035] An organic light emitting diode comprises a cathode, an anode and an organic layer, wherein the organic layer is one or more of a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, an electron injection layer and an electron transport layer, and the organic layer contains the above-mentioned platinum complex.

[0036] Preferably, the layer where the platinum complex is located is a light-emitting layer.

[0037] The invention is based on the platinum ligand framework of ONCN and improves the electroluminescent performance of the material by adding a modified structure.

[0038] The synthesis steps of this type of compound are simple and it is easy to have a mature process.

[0039] Compared with traditional organic electroluminescent compounds, the compound has higher electrophosphorescent electron yield and lower exciton radiation decay life.

[0040] The modification of the nitrogen-containing heterocyclic structure of the compound can significantly improve its luminous intensity and light extraction efficiency in specific optical components.

[0041] This type of structure has more modifiable sites, and the increased steric hindrance of the contained carbazole groups can effectively reduce the aggregation between molecules.

[0042] This type of compound can improve the molecular spatial configuration and the process preparation performance of the molecule by connecting functional groups at different sites.

[0043] The device results show that the platinum complex material of the present invention is applied to organic light-emitting diodes, which has lower driving voltage and higher luminous efficiency. In addition, the device life of the organic light-emitting diode based on the complex of the present invention is significantly better than the complex material in the comparative example, which can meet the requirements of the display industry for light-emitting materials and has good industrialization prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 is a structural diagram of an organic light emitting diode device of the present invention,

[0045] Among them, 10 represents a glass substrate, 20 represents an anode, 30 represents a hole injection layer, 40 represents a hole transport layer, 50 represents a light emitting layer, 60 represents an electron transport layer, 70 represents an electron injection layer, and 80 represents a cathode. DETAILED DESCRIPTION

[0046] The present invention does not require the synthesis method of the materials. In order to describe the present invention in more detail, the following examples are given, but are not limited thereto. The raw materials used in the following synthesis are all commercially available products unless otherwise specified.

[0047] Example 1: Synthesis of Complex 1

[0048]

[0049] Synthesis of compound 1b:

[0050] Take a 500ml single-mouth bottle, dissolve compound 1a (30.0g, 0.15mol) and I2 (39.0g, 0.15mol) in pyridine (200mL), heat to 120°C under nitrogen protection, and stir overnight. The above reaction solution was cooled to room temperature and filtered to obtain a brown solid. The solid was hot-beaten with methanol for 1 hour and filtered to obtain 44.0g of light yellow solid of compound 1b, with a yield of 72%.

[0051] H NMR (400MHz, DMSO) δ8.97 (d, J=5.6Hz, 2H), 8.74 (t, J=7.8Hz, 1H), 8.33-8.25 (m, 2H), 8.19 (s,1H),8.04(d,J=7.8Hz,1H),7.99(d,J=8.0Hz,1H),7.62(t,J=7.9Hz,1H),6.48(s,2H).

[0052] Synthesis of compound 1d:

[0053] Take a 500 ml single-mouth bottle and add compound 1c (20 g, 142.28 mmol), compound 1c-1 (19.08 g, 156.51 mmol), Pd 132 (1.5g, 2.11mmol) and potassium carbonate (58.99g, 426.84mmol) were added to dioxane (200ml) and water (50ml). Under nitrogen protection, the reaction was stirred at 80℃ for 2 hours. After cooling to room temperature, water and dichloromethane were added to extract twice, the organic phases were combined, the solvent was removed by rotation, and the residue was separated by column chromatography with a mixed solvent of ethyl acetate and n-hexane in a ratio of 1 to 100 to obtain 14.4g of white solid, with a yield of 55.54%.

[0054] 1 H NMR (400MHz, Chloroform-d) δ9.99 (s, 1H), 8.06-8.02 (m, 1H), 7.61 (td, J = 7.5, 1.4Hz, 1H), 7.52-7.30 (m, 7H).

[0055] Synthesis of compound 1e:

[0056] Take a 500ml three-necked flask, add compound 1d (20g, 109.76mmol) and compound 1d-1 (19.98g, 99.78mmol) to methanol (150ml), and heat to 47°C under nitrogen protection for reaction. Add the alkaline solution prepared by potassium hydroxide (27.99g, 498.90mmol) and water (38ml) dropwise into the three-necked flask, and the addition is completed in 0.5 hours. Stir and react for 2 hours. After cooling to room temperature, add water and dichloromethane to extract twice, combine the organic phases, spin off the solvent, and separate the residue by column chromatography with a mixed solvent of ethyl acetate and n-hexane in a ratio of 1 to 20 to obtain 27.78g of yellow liquid, with a yield of 81.7%.

[0057] 1H NMR (400MHz, Chloroform-d) δ7.84-7.79(m,1H),7.68(d,J=15.9Hz,1H),7.56(dd,J=7.6,1.6Hz,1H),7.50-7.27(m,10H),7.02-6.92(m,2H),3.86(s,3H).

[0058] Synthesis of compound 1f:

[0059] Take a 500ml single-mouth bottle, add compound 1e (27.3g, 86.83mmol), compound 1b (35.06g, 86.83mmol), ammonium acetate (58.66g, 0.78mol) to acetic acid (196ml). Under nitrogen protection, stir and react at 120℃ for 2 hours. After cooling to room temperature, concentrate most of the acetic acid, add water and dichloromethane to extract twice, combine the organic phases, spin to remove the solvent, and filter with a silica gel funnel. Recrystallize with tetrahydrofuran and methanol in a ratio of 1:4 to obtain 32.47g of white solid, with a yield of 76.1%.

[0060] 1 H NMR(400MHz,Chloroform-d)δ7.94(dd,J=7.5,1.7Hz,2H),7.82(d,J=1.3Hz,1H),7.73(d,J=7.8Hz,1H),7.57- 7.46(m,5H),7.41-7.36(m,1H),7.34-7.25(m,7H),7.11(t,J=7.5Hz,1H),7.00(d,J=8.2Hz,1H),3.81(s,3H).

[0061] Synthesis of compound 1g:

[0062] Take a 500ml single-mouth bottle, add compound 1f (23.5g, 47.72mmol), biboric acid pinacol ester (13.3g, 52.5mmol), potassium acetate (14.48g, 143.17mmol), bis (diphenylphosphino) ferrocene palladium dichloride (1.75g, 2.39mmol) to dioxane (240ml). Under nitrogen protection, stir and react at 90℃ for 6 hours. Add water and dichloromethane to extract twice, combine the organic phases, spin off the solvent, and separate the residue by column chromatography with a mixed solvent of ethyl acetate and n-hexane in a ratio of 1 to 10 to obtain 3.4g of white solid 20.33g, with a yield of 79.1%.

[0063] 1H NMR(400MHz,Chloroform-d)δ8.18(s,1H),8.12(d,J=7.9Hz,1H),7.93(dd,J=7.6,1.7Hz,1H),7.83(d,J=7.3Hz,1H),7.69(d, J=1.3Hz,1H),7.57-7.43(m,6H),7.40-7.26(m,6H),7.09(t,J=7.1Hz,1H),6.97(d,J=8.1Hz,1H),3.76(s,3H),1.39(s,12H).

[0064] Synthesis of compound 1h:

[0065] Take a 500ml single-mouth bottle, dissolve compound 1g (10g, 18.53mmol), compound 1g-1 (3.7g, 22.24ml), potassium carbonate (7.67g, 55.59mmol), tetrakistriphenylphosphine palladium (0.21g, 0.185mmol) in a mixed solvent of 1,4-dioxane (50ml) and water (10ml). Stir and react at 100℃ for 12 hours under nitrogen protection. The reaction solution is extracted twice with 100ml of ethyl acetate, the organic phase is dried, and the residue is separated by column chromatography with a mixed solvent of ethyl acetate and n-hexane in a ratio of 1 to 10 to obtain 6.5g of white solid, with a yield of 64.3%.

[0066] 1 H NMR(400MHz,Chloroform-d)δ8.56(d,J=3.6Hz,1H),8.20(t,J=2.0Hz,1H),8.04(d,J= 2.0Hz,1H),7.95(d,J=2.2Hz,1H),7.92(dd,J=8.6,1.3Hz,1H),7.92-7.86(m,2H),7.6 9-7.62(m,2H),7.61-7.43(m,8H),7.42-7.35(m,2H),7.31(dd,J=3.7,2.2Hz,1H),7.1 5(ddd,J=8.6,7.5,1.1Hz,1H),6.90(dd,J=7.7,1.2Hz,1H),3.90(s,3H),1.37(s,9H).

[0067] Synthesis of compound 1i:

[0068] Take a 250ml single-mouth bottle, put compound 1h (5.8g, 10.63mmol), pyridine hydrochloride (58g, 0.5mol) and o-dichlorobenzene (10ml) into the flask. Stir and react at 100℃ for 10 hours under nitrogen protection. The reaction solution is extracted twice with 100ml ethyl acetate, the organic phase is dried, and the residue is separated by column chromatography with a mixed solvent of ethyl acetate and n-hexane in a ratio of 1:5 to obtain 5.5g of the product yellow powder with a yield of 97.5%.

[0069] 1 H NMR(400MHz,Chloroform-d)δ8.56(d,J=3.6Hz,1H),8.20(t,J=2.0Hz,1H),8.04(d,J=2.2Hz,1H),8.00(dd,J=8.7,1.2Hz,1H),7.92-7.85(m,3H), 7.69-7.62(m,2H),7.61-7.43(m,8H),7.41-7.34(m,1H),7.31(dd,J=3.7 ,2.2Hz,1H),7.25(td,J=8.0,1.3Hz,1H),7.02-6.94(m,2H),1.37(s,9H).

[0070] Synthesis of complex 1:

[0071] Take a 1L single-mouth bottle, dissolve compound 1i (5g, 9.4mmol), K2PtCl4 (5.64g, 14.1mmol) and tetrabutylammonium bromide (TBAB, 438.6mg, 1.41mmol) in acetic acid (400mL). Under nitrogen protection, stir and react at 135℃ for 72 hours. Add water to the reaction solution to precipitate solids, which are filtered to obtain a crude product. The residue is passed through a silica gel funnel with dichloromethane, dried and mixed with silica gel, and separated by column chromatography with a mixed solvent of ethyl acetate and n-hexane in a ratio of 5 to 1 to obtain 5.12g of the product orange-yellow powder with a yield of 72.7%.

[0072] 1H NMR(500MHz,Chloroform-d)δ8.91(d,J=8.9Hz,1H),7.94(dd,J=8.2,1.2Hz,1H),7.80(d,J=2.2Hz,1H),7.74-7.69(m,2H),7.61-7.43(m,13H),7.41-7.34 (m,1H),7.30(td,J=7.4,1.2Hz,1H),7.17(dd,J=7.5,1.2Hz,1H),7.09(ddd, J=8.4, 7.5, 1.3Hz, 1H), 7.00 (s, 1H), 1.37 (s, 7H). ESI-MS (m / z): 723.2 (M+1).

[0073] Example 2: Synthesis of Complex 8

[0074]

[0075] Synthesis of compound 8b

[0076] Take a 2L three-necked flask, put compound 8a (20g, 117.15mmol), compound 8a-1 (29.08g, 234.3mmol), K2CO3 (48.5g, 351.45mmol) and DMF (1L), protect with nitrogen, stir at 150℃ for 72h. After the end, concentrate most of the DMF, add water and dichloromethane to extract twice, combine the organic phases, spin off the solvent to obtain a brown-black oily liquid, and separate it by column chromatography with a mixed solvent of ethyl acetate and n-hexane in a ratio of 1:15 to obtain a colorless oily compound 8b, a total of 18.01g, and a reaction yield of 69.5%.

[0077] 1 H NMR(400MHz,Chloroform-d)δ9.48(d,J=0.7Hz,1H),7.89(dd,J=7.0,1.2Hz,1H),7.79(dt,J=6.8,1.4Hz,1H),7.67-7.60(m,2H ),7.59-7.53(m,2H),7.37(td,J=7.0,1.3Hz,1H),7.30(td,J=6.6,1.2Hz,1H),7.21-7.14(m,1H),6.86(dd,J=5.1,1.2Hz,1H).

[0078] Synthesis of compound 8c

[0079] Take a 500ml single-mouth bottle, put compound 8b (17g, 76.8mmol), compound 1d-1 (11.5g, 76.8mmol), MeOH (250ml), add KOH aqueous solution (3.36g dissolved in 30ml water) dropwise under room temperature stirring, and stir at room temperature overnight (12h). After the reaction is completed, a large amount of solid precipitates, which is directly filtered and washed with a small amount of methanol for several times, and dried to obtain compound 8c, 22.28g of white solid, and the reaction yield is 82.1%.

[0080] 1 H NMR (400MHz, Chloroform-d) δ8.07-8.00 (m, 1H), 7.92 (dd, J = 7.4, 1.8Hz, 1H), 7. 79(dt,J=6.6,1.4Hz,1H),7.67-7.59(m,2H),7.54(dd,J=5.0,1.5Hz,2H),7.55-7 .47(m,2H),7.47(ddd,J=8.4,7.4,1.7Hz,1H),7.33-7.25(m,2H),7.16(dtd,J=17 .2,7.1,1.4Hz,2H),7.07(dd,J=8.4,1.3Hz,1H),6.88-6.83(m,1H),3.88(s,3H).

[0081] Synthesis of compound 8d

[0082] Take a 500ml single-mouth bottle, add compound 8c (15g, 42.4mmol), compound 1b (17.14g, 42.4mmol), ammonium acetate (70.0g) and acetic acid (200ml), and react at 130℃ for 8h. After the reaction is completed, cool the reaction solution and slowly add it to an ice-water bath. A large amount of gray-green solid samples precipitate, and filter and dry to obtain a gray-green crude product. After column chromatography with a mixed solvent of ethyl acetate and n-hexane in a ratio of 1:15, 12.1g of yellow foamy solid samples are obtained, and the reaction yield is 53.7%.

[0083] 1H NMR(400MHz,Chloroform-d)δ8.22(t,J=1.9Hz,1H),8.03-7.97(m,2H),7.96-7.90(m,2H), 7.80(dt,J=7.0,1.2Hz,1H),7.67(dd,J=6.9,1.2Hz,1H),7.63(ddd,J=12.5,6.3,1.4Hz,2H) ,7.58-7.51(m,2H),7.46-7.38(m,2H),7.38(dd,J=7.6,1.2Hz,1H),7.29(dtd,J=8.4,6.8, 1.2Hz,2H),7.21-7.11(m,2H),6.90(dd,J=7.7,1.2Hz,1H),6.88-6.83(m,1H),3.90(s,3H).

[0084] Synthesis of compound 8e

[0085] Take a 500ml single-mouth bottle, put compound 8d (7.6g, 14.3mmol), biboric acid pinacol ester (5.44g, 21.4mmol), palladium acetate (160.5mg, 0.72mmol), X-phos (667.4mg, 1.4mmol), potassium acetate (4.2g, 42.9mmol) and dioxane (250ml), protect with nitrogen, stir and react at 90℃ for 9h. After the reaction is completed, directly filter, take the mother liquor and spin dry directly, and separate it by column chromatography with a mixed solvent of ethyl acetate and n-hexane in a ratio of 1 to 15. Collect and obtain compound 8e as a total of 6.4g of white solid, with a reaction yield of 77.36%.

[0086] 1 H NMR(400MHz,Chloroform-d)δ8.06(t,J=1.9Hz,1H),7.99(d,J=2.2Hz,1H),7.95-7.90(m,2 H),7.82-7.76(m,2H),7.74(ddd,J=7.1,1.9,1.2Hz,1H),7.67(dd,J=6.9,1.2Hz,1H),7.63 (ddd,J=12.5,6.3,1.4Hz,2H),7.55-7.47(m,2H),7.45-7.35(m,2H),7.32-7.25(m,2H),7. 21-7.12(m,2H),6.90(dd,J=7.7,1.2Hz,1H),6.87-6.83(m,1H),3.90(s,3H),1.24(s,12H).

[0087] Synthesis of compound 8f

[0088] Take a 500 ml single-mouth bottle and put compound 8e (6 g, 10.37 mmol), compound 1g-1 (2.1 g, 12.4 mmol), Pd 132 (367 mg, 0.52 mmol), K2 CO3 (4.29 g, 31.1 mmol), dioxane (160 ml) and water (40 ml) were added under nitrogen protection and stirred at 90 °C for 16 h. After the reaction, dioxane was removed by vortexing, and the reaction solution was extracted twice with 100 ml of ethyl acetate. The organic phase was dried and separated by column chromatography with a mixed solvent of ethyl acetate and n-hexane in a ratio of 1 to 6. A total of 4.1 g of light yellow solid compound 8f was obtained, and the reaction yield was 67.2%.

[0089] 1 H NMR(400MHz,Chloroform-d)δ8.56(d,J=3.6Hz,1H),8.20(t,J=2.0Hz,1H),8.02(d,J=2.0Hz, 1H),7.96-7.86(m,4H),7.80(dt,J=6.9,1.2Hz,1H),7.70-7.63(m,3H),7.63(ddd,J=12.4,5. 6,1.6Hz,2H),7.53(d,J=5.1Hz,1H),7.46-7.35(m,2H),7.34-7.28(m,2H),7.30-7.25(m,1H) ,7.21-7.11(m,2H),6.90(dd,J=7.7,1.2Hz,1H),6.88-6.83(m,1H),3.90(s,3H),1.37(s,9H).

[0090] Synthesis of compound 8g

[0091] Take a 250ml single-mouth bottle, put 8f (4g, 6.82mmol), pyridine hydrochloride (40g) and 2.4mL o-dichlorobenzene, protect with nitrogen, and react at 180℃ for 12h. After the reaction is completed, extract and wash twice with dichloromethane and water system, and take the organic phase to dryness. After column chromatography with a mixed solvent of ethyl acetate and n-hexane in a ratio of 1:6, 3.1g of compound 8g as a light yellow solid is obtained, and the reaction yield is 79.5%.

[0092] 1H NMR(400MHz,Chloroform-d)δ8.56(d,J=3.6Hz,1H),8.20(t,J=2.0Hz,1H),8.05-7.98( m,2H),7.92-7.86(m,3H),7.80(dt,J=7.1,1.3Hz,1H),7.70-7.59(m,5H),7.53(d,J=5. 1Hz,1H),7.46-7.39(m,1H),7.34-7.28(m,2H),7.30-7.25(m,1H),7.25(td,J=8.0,1.3 Hz,1H),7.17(td,J=6.8,1.6Hz,1H),7.02-6.94(m,2H),6.88-6.83(m,1H),1.37(s,9H).

[0093] Synthesis of complex 8

[0094] Take a 500ml single-mouth bottle, dissolve compound 8g (2.5g, 4.37mmol) and K2PtCl4 (2.47g, 6.56mmol) and tetrabutylammonium bromide (TBAB, 211.3mg, 0.65mmol) in acetic acid (250mL). Under nitrogen protection, stir and react at 135℃ for 72 hours. Add water to the reaction solution to precipitate solids, which are filtered to obtain a crude product. The residue is passed through a silica gel funnel with dichloromethane, dried and mixed with silica gel, and separated by column chromatography with a mixed solvent of ethyl acetate and n-hexane in a ratio of 1 to 5 to obtain the product. The orange-yellow powder complex 8, a total of 2.34g, has a yield of 70.1%.

[0095] 1 H NMR(400MHz,Chloroform-d)δ8.91(d,J=8.9Hz,1H),8.08-8.03(m,2H),7.94(dd,J=8.2,1. 2Hz,1H),7.80(td,J=3.7,3.1,1.5Hz,2H),7.67-7.47(m,7H),7.43(ddd,J=7.3,6.3,1.2Hz ,1H),7.29(tdd,J=7.0,6.2,1.2Hz,3H),7.18(ddd,J=7.5,4.8,1.4Hz,2H),7.09(ddd,J=8. 4,7.5,1.3Hz,1H),7.00(s,1H),6.88-6.83(m,1H),1.37(s,9H).ESI-MS(m / z):764.2(M+1).

[0096] Example 3: Synthesis of Complex 16

[0097]

[0098] Synthesis of compound 16b

[0099] Compound 8a (6.68 g, 40.0 mmol), 8b (10.0 g, 80.0 mmol), K2CO3 (8.28 g, 60.0 mmol) and DMF (400 ml) were added to a 1L three-necked flask, and the mixture was stirred at 150°C for 72 h under nitrogen protection. After the reaction, the mixture was extracted and washed twice with dichloromethane and water; the organic phase was spin-dried to obtain a brown-black oily liquid, and the sample was separated by column chromatography using a mixed solvent of ethyl acetate and n-hexane in a ratio of 1:15; Compound 16b was obtained, 17.0 g of a light yellow oily substance, and the reaction yield was 78.4%.

[0100] 1H NMR (400MHz, CDCl3) δ9.60(d,J=0.7Hz,1H),8.22(dd,J=7.8,1.4Hz,1H),8.18(d,J=7.5Hz,2H),7.85(td,J=7.7,1.6Hz ,1H),7.67(t,J=7.6Hz,1H),7.55(dd,J=7.9,0.7Hz,1H),7.46-7.38(m,2H),7.37-7.29(m,2H),7.17(d,J=8.1Hz,2H).

[0101] Synthesis of compound 16c

[0102] Take a 250ml single-mouth bottle, put compound 16b (5.42g, 20.0mmol), compound 1d-1 (3.0g, 20.0mmol), MeOH (80ml), add KOH aqueous solution (1.12g dissolved in 10ml water) dropwise under room temperature stirring, and stir at room temperature overnight (16h). After the reaction is completed, a large amount of solid precipitates, which is directly filtered and washed with a small amount of methanol for several times, and dried to obtain a white solid compound 16c of 6.8g, and the reaction yield is 84.4%.

[0103] 1H NMR (400MHz, CDCl3) δ8.12(d,J=7.7Hz,2H),8.00-7.94(m,1H),7.59(p,J=7.5Hz,2H),7.47-7.41(m,1H),7.35(t,J=7.6Hz,2 H),7.28(d,J=7.1Hz,2H),7.23(s,1H),7.13(d,J=16.1Hz,1H),7.07-6.97(m,4H),6.69(dd,J=15.9,8.0Hz,2H),3.57(s,3H).

[0104] Synthesis of compound 16d

[0105] Take a 250ml single-mouth bottle, add compound 16c (12.9g, 32.0mmol), 1b (12.9g, 32.0mmol), ammonium acetate (62.0g) and acetic acid (130ml), and react at 130℃ for 8h. After the reaction is completed, cool the reaction solution and slowly add it to an ice-water bath. A large amount of gray-green solid samples precipitate, which are filtered and dried to obtain a gray-green crude product, which is separated by column chromatography with a mixed solvent of ethyl acetate and n-hexane in a ratio of 1:15; 10.5g of yellow foamy solid compound 16d is obtained, and the reaction yield is 56.5%.

[0106] 1H NMR (400MHz, CDCl3) δ8.08 (d, J = 7.7Hz, 2H), 7.77 (t, J = 3.8Hz, 2H), 7.75-7. 71(m,1H),7.68(dt,J=7.2,3.6Hz,2H),7.66-7.61(m,1H),7.53(d,J=1.6Hz ,1H),7.40-7.35(m,2H),7.35-7.31(m,2H),7.24(s,1H),7.18-7.11(m,3H) ,7.09(s,1H),7.06(dd,J=8.0,1.4Hz,2H),6.99-6.91(m,2H),3.74(s,3H).

[0107] Synthesis of compound 16e

[0108] Take a 250ml single-mouth bottle, put compound 16d (3.5g, 6.0mmol), biboric acid pinacol ester (2.29g, 9.0mmol), palladium acetate (67mg, 0.3mmol), X-phos (283mg, 0.6mmol), potassium acetate (1.77g, 18.0mmol) and dioxane (100ml), protect with nitrogen, stir and react at 90℃ for 12h. After the reaction is completed, filter directly, take the mother liquor and spin dry directly, separate by column chromatography with a mixed solvent of ethyl acetate and n-hexane in a ratio of 1:15; 3.5g of white product compound 16e is obtained, and the reaction yield is 92.5%.

[0109] 1H NMR (400MHz, CDCl3) δ8.18(s,1H),8.03(d,J=7.7Hz,2H),7.76(dd,J=12.5,5.8Hz,2H),7.65(dt,J=11.3,7.6Hz,3H),7.60-7.52(m,2H),7.4 6(d,J=7.9Hz,1H),7.34-7.26(m,5H),7.17(dd,J=18.0,7.8Hz,4H),6.98(t,J=7.4Hz,1H),6.86(d,J=8.2Hz,1H),3.56(s,3H),1.36(s,12H).

[0110] Synthesis of compound 16f

[0111] Take a 500ml single-mouth bottle, put compound 16e (5.9g, 11.8mmol, 1.0eq), compound 1g-1 (2.4g, 14.1mmol), tris [dibenzylideneacetone] dipalladium (538mg, 0.59mmol, 0.05eq), X-phos (563mg, 1.18mmol), K2CO3 (4.88g, 35.3mmol), dioxane (160ml) and water (40ml), protect with nitrogen, stir and react at 90℃ for 16h. After the reaction, remove dioxane, extract and wash with EA / water system, take the organic phase and spin dry, separate with ethyl acetate and n-hexane in a ratio of 1:6 by column chromatography, and obtain 3.6g of light yellow solid compound 16f, with a reaction yield of 60.3%.

[0112] 1H NMR (400MHz, CDCl3) δ8.61(d,J=5.2Hz,1H),8.38(s,1H),8.01(d,J=7.7Hz,2H),7 .88(d,J=7.3Hz,1H),7.81-7.76(m,1H),7.68(dd,J=6.3,4.4Hz,3H),7.65(d,J=6 .9Hz,1H),7.64-7.56(m,2H),7.40-7.26(m,5H),7.25-7.19(m,2H),7.16(t,J=7. 0Hz, 4H), 6.98 (t, J = 7.5Hz, 1H), 6.89 (d, J = 8.3Hz, 1H), 3.60 (s, 3H), 1.37 (s, 9H).

[0113] Synthesis of compound 16g

[0114] Take a 50ml single-mouth bottle, put compound 16f (2.4g, 3.77mmol), pyridine hydrochloride (24g) and 2.4mL o-dichlorobenzene, protect with nitrogen, and react at 175℃ for 12h. After the reaction, extract and wash twice with dichloromethane / water system, take the organic phase and spin dry; separate with ethyl acetate and n-hexane in a ratio of 1:6 by column chromatography to obtain a light yellow solid compound 16g, weighing 2.0g, and the reaction yield is 85.21%.

[0115] 1H NMR (400MHz, CDCl3) δ8.64(d,J=5.2Hz,1H),8.33(s,1H),8.04(d,J=7.7Hz,2H),7 .97(d,J=7.6Hz,1H),7.86-7.81(m,1H),7.77-7.70(m,3H),7.69-7.64(m,1H),7.4 9-7.43(m,2H),7.42-7.31(m,4H),7.29(dd,J=5.2,1.7Hz,1H),7.24-7.16(m,3H) ,7.13(d,J=8.1Hz,2H),6.89(d,J=8.3Hz,1H),6.64(d,J=6.1Hz,2H),1.40(s,9H).

[0116] Synthesis of complex 16

[0117] Take a 250ml single-mouth bottle, put in compound 16g (1.5g, 2.41mmol), K2PtCl4 (1.2g, 2.90mmol), tetrabutylammonium bromide (TBAB, 117mg, 0.36mmol) and acetic acid (150mL), protect with nitrogen, and react at 130 degrees for 48h. After the reaction is completed, add excess deionized water, solid precipitates, filter, dissolve the solid with dichloromethane, spin dry the organic phase and use dichloromethane as eluent for column chromatography separation, and the obtained crude sample is separated and purified by column chromatography with a mixed solvent (n-hexane: dichloromethane: ethyl acetate = 10:10:1) to obtain a total of 1.5g of complex 16 orange solid. Finally, recrystallize with dichloromethane and n-hexane in a ratio of 1:2 to obtain 1.27g of orange solid, and the reaction yield is 64.6%.

[0118] 1H NMR (400MHz, CDCl3) δ8.69 (d, J = 6.0 Hz, 1H), 8.06 (d, J = 7.8 Hz, 2H), 7.88-7. 83(m,1H),7.78-7.73(m,2H),7.68(dd,J=8.7,4.4Hz,2H),7.59(s,1H),7.37 (t,J=7.3Hz,2H),7.28(s,2H),7.21(dd,J=16.6,6.1Hz,6H),7.16(s,1H),6 .83(t,J=7.6Hz,1H),6.78-6.69(m,2H),6.35(t,J=7.4Hz,1H),1.39(s,9H).

[0119] Those skilled in the art should be aware that the above preparation method is only an illustrative example, and those skilled in the art can obtain other compound structures of the present invention by improving it.

[0120] Embodiment 4:

[0121] Under nitrogen atmosphere, about 5.0 mg of fully dried platinum complex samples 1, 8, and 16 were weighed respectively, the heating scan rate was set to 10°C / min, the scan range was 25-800°C, and the thermal decomposition temperatures were measured to be 416, 403, and 427°C (temperatures corresponding to 0.5% thermal weight loss), respectively, indicating that this type of complex has very good thermal stability.

[0122] Embodiment 5:

[0123] The organic light emitting diode is prepared by using the complex luminescent material of the present invention. The device structure is shown in FIG. Figure 1 .

[0124] First, the transparent conductive ITO glass substrate 10 (with the anode 20 thereon) is washed with a detergent solution and deionized water, ethanol, acetone, and deionized water in sequence, and then treated with oxygen plasma for 30 seconds.

[0125] Then, HATCN was vapor-deposited to a thickness of 10 nm on the ITO as the hole injection layer 30 .

[0126] Then, compound HT was evaporated to form a hole transport layer 40 with a thickness of 40 nm.

[0127] Then, a 20 nm thick light emitting layer 50 is evaporated on the hole transport layer. The light emitting layer is composed of a mixed doping of platinum complex 1 (20%) and CBP (80%).

[0128] Then, AlQ3 was evaporated to a thickness of 40 nm on the light-emitting layer as the electron transport layer 60 .

[0129] Finally, 1 nm LiF was evaporated as the electron injection layer 70 and 100 nm Al was evaporated as the device cathode 80 .

[0130] Example 6: Complex 8 was used to replace complex 1, and an organic light emitting diode was prepared by the method described in Example 5.

[0131] Example 7: Complex 16 was used to replace complex 1, and an organic light emitting diode was prepared by the method described in Example 5.

[0132] Comparative Example 1:

[0133] The organic light emitting diode was prepared by the method described in Example 7 using complex Ref-1 (CN110872325A) instead of complex 16.

[0134] Comparative Example 2:

[0135] The organic light-emitting diode was prepared by the method described in Example 7 using complex Ref-2 (Chem. Sci., 2014, 5, 4819) instead of complex 16.

[0136] The structural formulas of HATCN, HT, AlQ3, Ref-1, Ref-2 and CBP in the device are as follows:

[0137]

[0138]

[0139] The organic electroluminescent devices in Example 5, Example 6, Example 7, Comparative Example 1, and Comparative Example 2 are at 20 mA / cm 2 The device performance at the current density is listed in Table 1:

[0140] Table 1

[0141]

[0142] It can be seen from the data in Table 1 that under the same conditions, the platinum complex material of the present invention is applied to the organic light-emitting diode, which has a lower driving voltage and a higher luminous efficiency. In addition, the device life of the organic light-emitting diode based on the complex of the present invention is significantly better than the complex material in the comparative example, which can meet the requirements of the display industry for light-emitting materials and has a good industrialization prospect.

[0143] The above-mentioned various embodiments are only used as examples and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, the various materials and structures in the present invention can be replaced by other materials and structures. It should be understood that those skilled in the art can make many modifications and changes based on the ideas of the present invention without creative work. Therefore, the technical solutions that can be obtained by technical personnel through analysis, reasoning or partial research on the basis of the prior art should all be within the scope of protection limited by the claims.

Claims

1. A heterocyclic modified platinum complex containing an ONCN tetradentate ligand, the structure of which is shown in formula (I), in: R 1 To R 12 , R 14 To R 15 Each is independently selected from the group consisting of hydrogen, deuterium, halogen, cyano, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms; R 13 is selected from substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms; Ar is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms; The heteroatom in the heteroaryl group is one or more of N, S, and O; The substitution is substitution with halogen, cyano, C1-C4 alkyl or fluorinated C1-C4 alkyl.

2. The platinum complex according to claim 1, wherein R 1 To R 12 , R 14 To R 15 Each is independently selected from the group consisting of hydrogen, deuterium, halogen, cyano, substituted or unsubstituted alkyl having 1 to 6 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 6 ring carbon atoms; R 13 is selected from substituted or unsubstituted alkyl having 1 to 6 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 6 ring carbon atoms; Ar is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms; The substitution is substitution with halogen, cyano, C1-C4 alkyl or fluorinated C1-C4 alkyl.

3. The platinum complex according to claim 1, wherein R 1 To R 12 , R 14 To R 15 Each is independently selected from: hydrogen, deuterium, halogen, cyano, C1-C4 alkyl, substituted or unsubstituted cycloalkyl having 3-6 ring carbon atoms; R 13 is selected from C1-C4 alkyl, substituted or unsubstituted cycloalkyl having 3-6 ring carbon atoms; Ar is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms; The substitution is substitution with halogen, cyano, C1-C4 alkyl or fluorinated C1-C4 alkyl.

4. The platinum complex according to claim 1, wherein R 1 To R 12 , R 14 To R 15 Each is independently selected from the group consisting of hydrogen, deuterium, cyano, methyl, isopropyl, isobutyl, tert-butyl, substituted or unsubstituted cyclopentyl, substituted or unsubstituted cyclohexyl; R 13 is selected from methyl, isopropyl, isobutyl, tert-butyl, substituted or unsubstituted cyclopentyl, substituted or unsubstituted cyclohexyl; Ar is selected from substituted or unsubstituted phenyl, substituted or unsubstituted pyridyl, substituted or unsubstituted pyrazinyl, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted imidazolyl, substituted or unsubstituted carbazolyl; The substitution is substitution with halogen, cyano, C1-C4 alkyl or fluorinated C1-C4 alkyl.

5. The platinum complex according to claim 1, wherein in the general formula (I), R 1 To R 12 , R 14 To R 15 Each is independently selected from: hydrogen, deuterium, methyl, tert-butyl, cyano; R 13 is selected from methyl and tert-butyl; Ar is selected from substituted or unsubstituted phenyl, substituted or unsubstituted pyridyl, substituted or unsubstituted imidazolyl, substituted or unsubstituted carbazolyl; The substitution is substitution with halogen, cyano, C1-C4 alkyl or fluorinated C1-C4 alkyl.

6. The platinum complex according to claim 1, wherein in the general formula (I), R 1 To R 15 R 13 is tert-butyl, and the rest are hydrogen; Ar is selected from a substituted or unsubstituted phenyl group, a substituted or unsubstituted pyridyl group, or a substituted or unsubstituted carbazolyl group.

7. The platinum complex according to claim 1, which is one of the following compounds: 。 8. The precursor of the platinum complex according to claim 1, i.e., the ligand, has the following structural formula: Where R 1 To R 15 , Ar as defined in claim 1.

9. Use of the platinum complex according to any one of claims 1 to 7 in an organic light emitting diode, an organic thin film transistor, an organic photovoltaic device, a light emitting electrochemical cell or a chemical sensor.

10. An organic light emitting diode comprising a cathode, an anode and an organic layer, wherein the organic layer is one or more of a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, an electron injection layer and an electron transport layer, and the organic layer contains the platinum complex according to any one of claims 1 to 7.

11. The organic light emitting diode according to claim 10, wherein the platinum complex according to any one of claims 1 to 7 is located in the light emitting layer.

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