Tetradentate platinum complex luminescent material based on a tetraarylethylene backbone structure and its applications

Abstract

The present invention relates to a tetradentate platinum complex luminescent material based on a tetraarylethylene backbone structure and its applications. The platinum complex is a compound having the structure of formula (I). Such materials have the property of aggregation-induced emission, with a relatively high luminescence quantum yield and a short excited state lifetime. The present invention also provides an organic electro-optical device, comprising a cathode, an anode and an organic layer, where 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 transport layer, and an electron injection layer, and at least one layer of the organic layer contains the compound in formula (I).

Description

Technical Field

[0001] The present invention relates to the field of metal complex luminescent materials, and particularly relates to a class of tetradentate platinum complexes based on a tetraarylethylene backbone structure and their applications in organic light-emitting diodes. Background Art

[0002] Organic light-emitting diodes (OLEDs) have many advantages such as self-luminescence, short response time, wide operating temperature range, and high flexibility, and have broad application prospects in the new generation of flat panel displays, solid-state lighting, and flexible displays, becoming one of the competition focuses in the high-tech fields of various countries. However, currently, OLEDs still have the problem of relatively short device lifetime, and the luminous efficiency also needs to be further improved.

[0003] The performance of OLED devices depends to a great extent on the luminescent materials used. Early fluorescent OLEDs usually can only utilize singlet excitons for luminescence, and the triplet excitons generated in the devices cannot luminesce but return to the ground state through non-radiative ways, which limits the improvement of OLED efficiency. In 1998, Professor Chi-Ming Che and his collaborators at the University of Hong Kong used transition metal complexes to achieve triplet luminescence, effectively improving the exciton utilization rate. In the same year, Thompson et al. also reported the electrophosphorescence phenomenon of transition metal complexes. Phosphorescent OLEDs can effectively utilize both triplet and singlet excitons, and theoretically can achieve 100% internal quantum efficiency, promoting the commercialization process of OLEDs. The regulation of the emission color of OLEDs can be achieved through the structural design of luminescent materials. An OLED can include one or more light-emitting layers to achieve the desired spectrum. Green, yellow, and red phosphorescent materials have been commercialized. Commercial OLED displays usually use blue fluorescence and yellow, or green and red phosphorescence combinations to achieve full-color display. Luminescent materials with higher efficiency and longer service life are urgently needed in the current industry.

[0004] Compared with red and green luminescent materials, the research on blue phosphorescent materials lags behind relatively, and the types and quantities of related materials are both small, which becomes the main factor hindering their development. Developing highly efficient and stable blue phosphorescent materials is of great significance for further promoting the industrial application of blue phosphorescent OLED devices. Summary of the Invention

[0005] In view of the above problems, the present invention provides a class of tetradentate platinum complex luminescent materials based on a tetraarylethylene backbone structure, and the application of such materials in organic light-emitting diodes shows good luminous efficiency and device lifetime.

[0006] The present invention also provides an organic light-emitting diode based on the platinum complex.

[0007] The tetradentate platinum complex is a compound having the structure of formula (I):

[0008]

[0009] Wherein:

[0010] X 1 -X 9 are independently selected from N or CR 6 ;

[0011] R 1 to R 6 are independently selected from: hydrogen, deuterium, amino, halogen, carbonyl, carboxyl, cyano, phosphino, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted alkenyl having 2-20 carbon atoms, substituted or unsubstituted alkoxy having 1-20 carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms;

[0012] Ar 1 to Ar 5 is a five- or six-membered aromatic ring or heteroaromatic ring;

[0013] The heteroatom in the heteroaryl or heteroaromatic ring is one or more of N, O, S;

[0014] The substitution is by halogen, amino, cyano, C1-C4 alkyl.

[0015] Preferably, R 1 to R 6 are each independently selected from: hydrogen, deuterium, halogen, amino, cyano, substituted or unsubstituted alkyl having 1-6 carbon atoms, substituted or unsubstituted cycloalkyl having 3-6 ring carbon atoms, substituted or unsubstituted alkenyl having 2-6 carbon atoms, substituted or unsubstituted alkoxy having 1-6 carbon atoms, substituted or unsubstituted aryl having 6-12 carbon atoms, or substituted or unsubstituted heteroaryl having 3-6 carbon atoms.

[0016] Preferably, R 1 to R 6 are each independently selected from: hydrogen, deuterium, halogen, C1-C4 alkyl, cyano, substituted or unsubstituted cycloalkyl having 3-6 ring carbon atoms, substituted or unsubstituted aryl having 6-12 carbon atoms, substituted or unsubstituted heteroaryl having 3-6 carbon atoms.

[0017] Preferably, R 1 to R 6Each is independently selected from: hydrogen, deuterium, fluorine, methyl, isopropyl, isobutyl, tert-butyl, cyano, substituted or unsubstituted cyclopentyl, substituted or unsubstituted cyclohexyl, substituted or unsubstituted phenyl, substituted or unsubstituted pyridyl, substituted or unsubstituted pyrazinyl, substituted or unsubstituted pyrimidinyl.

[0018] Preferably, the general formula (I) has the following structure:

[0019]

[0020] R 1 to R 6 Each is independently selected from: hydrogen, deuterium, fluorine, methyl, tert-butyl, cyano, substituted or unsubstituted cyclopentyl, substituted or unsubstituted cyclohexyl, or substituted or unsubstituted phenyl.

[0021] Ar 1 、Ar 4 、Ar 5 are each independently selected from a five-membered aromatic ring, a six-membered aromatic ring, a five-membered heteroaromatic ring, a six-membered heteroaromatic ring; Ar 2 、Ar 3 are each independently selected from a six-membered aromatic ring or a six-membered heteroaromatic ring.

[0022] More preferably, the general formula (I) has the following structure:

[0023]

[0024] X 1 -X 3 、X 6 -X 9 are independently selected from CR 6 ; X 4 -X 5 is independently selected from N or CR 6 .

[0025] Wherein Ar 1 、Ar 4 、Ar 5 are selected from phenyl or pyridyl, Ar 2 、Ar 3 are each independently selected from a six-membered aromatic ring, X 1 -X 3 、X 6 -X 9 、X 4 -X 5 are independently selected from CR 6 .

[0026] R 1 to R 6 Each is independently selected from: hydrogen, deuterium, fluorine, tert-butyl.

[0027] Examples of platinum complexes according to the present invention are listed below, but are not limited to the structures listed:

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034] The precursor structural formulas of the above complexes are as follows:

[0035]

[0036] The present invention also provides an application of the above platinum complex in an organic optoelectronic device, and the optoelectronic device includes, but is not limited to, an organic light-emitting diode (OLED), an organic thin-film transistor (OTFT), an organic photovoltaic device (OPV), a light-emitting electrochemical cell (LCE), and a chemical sensor, preferably an OLED.

[0037] An organic light-emitting diode (OLED) containing the above platinum complex, and the platinum complex is a light-emitting material in the light-emitting device.

[0038] The organic light-emitting diode in the present invention includes a cathode, an anode, and an organic layer, and 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 injection layer, and an electron transport layer, and these organic layers do not have to exist in each layer; at least one of the hole injection layer, the hole transport layer, the hole blocking layer, the electron injection layer, the light-emitting layer, and the electron transport layer contains the platinum complex represented by formula (I).

[0039] Preferably, the layer where the platinum complex represented by formula (I) is located is the light-emitting layer or the electron transport layer.

[0040] The total thickness of the organic layer of the device in the present invention is 1-1000 nm, preferably 1-500 nm, and more preferably 5-300 nm.

[0041] The organic layer can form a thin film by evaporation or solution method.

[0042] A series of tetradentate platinum complex light-emitting materials based on a tetraaryl skeleton structure disclosed in the present invention have the property of aggregation-induced emission, can effectively improve the emission color purity, and have a short excited state lifetime, thereby improving the emission efficiency and device stability. Brief Description of the Drawings

[0043] Figure 1 This is the structural diagram of the organic light-emitting diode device of the present invention,

[0044] wherein 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 of the Invention

[0045] The present invention will be further described in detail below in conjunction with the embodiments.

[0046] All raw materials used in the embodiments are commercially available products.

[0047] Example 1: Preparation of Complex 57

[0048]

[0049] Synthesis of Compound 57b

[0050] Take a 2 L single-necked flask and sequentially add to it: 57a (67 g, 177.2 mmol, synthesized with reference to Organometallics, 2021, 40, 472 - 481), B 2 Pin 2 (67.5 g, 265.9 mmol, Pd(dppf)Cl 2 (6.5 g, 8.9 mmol), cesium acetate (68 g, 354.4 mmol) and toluene (670 ml). Under nitrogen protection, react at 110 °C for 24 h. After the reaction is completed, filter by suction, rotary evaporate the filtrate at 60 °C, and perform silica gel column chromatography separation to obtain 58 g of a white solid with a yield of 76.8%. HRMS(ESI)(m / z): 427.2550[M + H] + .

[0051] Synthesis of Compound 57c

[0052] Take a 2 L single-necked flask and sequentially add to it: 57b (58 g, 136.1 mmol), 3-methoxybenzyl chloride (31.8 g, 204.2 mmol), Pd(dppf)Cl 2 (4.9 g, 6.8 mmol), K 3 PO 4 .3H 2O (108.2 g, 408.3 mmol) and toluene / ethanol / water (200 / 200 / 100 mL), under nitrogen protection, react at 100 °C for 16 h. After the reaction is completed, filter by suction, rotary evaporate the filtrate, perform silica gel column chromatography separation, obtain 50 g of pale yellow oily substance, with a yield of 87.4%. HRMS(ESI)(m / z): 421.2214 [M+H] + 。

[0053] Synthesis of Compound 57d

[0054] Take a 1 L single-necked flask, and successively add to it: 57c (50 g, 119 mmol), tBuONa (22.8 g, 238 mmol) and DMSO (500 mL). Under an oxygen atmosphere, react at 50 °C for 16 h. After the reaction is completed, add 2 L of water and adjust the pH to 6 - 7. Extract with ethyl acetate (500 mL×3). Rotary evaporate the organic phase, perform silica gel column chromatography separation, obtain 38.6 g of white solid, with a yield of 74.8%. HRMS(ESI)(m / z): 435.1985 [M+H] + 。

[0055] Synthesis of Compound 57e

[0056] Under nitrogen protection, dissolve diphenylmethane (11.6 g, 69.0 mmol) in tetrahydrofuran (150 mL). At -78 °C, dropwise add n-butyllithium (2 M, 40 mL) to the above solution, stir and react for 1 h, then raise the temperature to -40 °C and continue to react for 0.5 h. Dropwise add Compound 57d (20.0 g, 46.0 mmol) in tetrahydrofuran (100 mL) to the above solution and continue to react for 15 h. After the reaction is completed, add 500 mL of water, extract with ethyl acetate (200 mL×3), evaporate the organic phase under reduced pressure, and perform silica gel column chromatography separation on the residue to obtain 19.2 g of light yellow solid, with a yield of 71.3%. HRMS(ESI)(m / z): 585.2921 [M+H] + 。

[0057] Synthesis of Compound 57f

[0058] Under nitrogen protection, heat the mixture of Compound 57e (19.0 g, 32.5 mmol) and pyridine hydrochloride (100 g) to 190 °C and react for 6 h. Cool to room temperature, add 500 mL of water, extract with ethyl acetate (200 mL×3), evaporate the organic phase under reduced pressure, and perform silica gel column chromatography separation on the residue to obtain 17.9 g of light yellow solid, with a yield of 96.5%. HRMS(ESI)(m / z): 571.2781 [M+H] + 。

[0059] Synthesis of Compound 57g

[0060] Take a 250ml three-necked flask, put 57f (12.6g, 22.1mmol), pyridine (3.49g, 44.2mmol) and dichloromethane (150ml), add trifluoromethanesulfonic anhydride (9.34, 33.1mmol) dropwise under nitrogen protection in an ice bath, naturally warm to room temperature and stir overnight. After the reaction is completed, add water (100mL), extract with dichloromethane (100ml*3), evaporate the organic phase under reduced pressure, and separate the residue by silica gel column chromatography to obtain 9.6g of light yellow solid, with a yield of 61.9%. HRMS (ESI) (m / z): 703.2200 [M+H] + .

[0061] Synthesis of compound 57h

[0062] Under nitrogen protection, a mixture of 57g (6.70g, 9.53mmol), sodium tert-butoxide (1.83g, 19.1mmol), N-phenyl-o-phenylenediamine (2.1g, 11.4mmol), palladium acetate (0.21g, 0.95mmol), tri-tert-butylphosphine (0.23g, 1.14mmol) and toluene (100mL) was heated to 120°C for 16 hours. After the reaction, water (100mL) was added, and the mixture was extracted with dichloromethane (100ml*3). The organic phase was evaporated under reduced pressure, and the residue was separated by silica gel column chromatography to obtain 5.4g of light yellow solid with a yield of 76.9%. HRMS (ESI) (m / z): 737.3660 [M+H] + .

[0063] Synthesis of compound 57i

[0064] Under nitrogen protection, a mixture of compound 57h (2.1 g, 2.85 mmol), triethyl orthoformate (20 mL), ammonium hexafluorophosphate (2.79 g, 17.1 mmol) and acid salt (0.2 mL) was heated to 80°C, stirred for 24 hours, and filtered to obtain 1.9 g of product. HRMS (ESI) (m / z): 747.3500 [M-PF6] + .

[0065] Synthesis of complex 57

[0066] Under nitrogen protection, compound 57i (900 mg, 1.01 mmol), Pt(COD)Cl2 (358 mg, 1.21 mmol) and sodium acetate (165 mg, 2.02 mmol) were added to a solution of tetrahydrofuran (20 mL), and the reaction was carried out at 120 °C for 24 hours. After the reaction was completed, water (100 mL) was added, and the mixture was extracted with dichloromethane (100 ml * 3). The organic phase was removed by distillation under reduced pressure, and the residue was separated by silica gel column chromatography to obtain 0.32 g of a light yellow solid with a yield of 33.7%. HRMS(ESI)(m / z): 940.2985[M+H] + .

[0067] Example 2: Preparation of Complex 83

[0068]

[0069] Synthesis of Compound 83a

[0070] Under nitrogen protection, bis(2-pyridyl)methane (4.0 g, 23.5 mmol) was dissolved in tetrahydrofuran (150 mL). At -78 °C, n-butyllithium (2 M, 10 mL) was added dropwise to the above solution, and the mixture was stirred for 1 h. Subsequently, the temperature was raised to -40 °C and the reaction was continued for 0.5 h. Compound 57d (8.5 g, 19.6 mmol) in tetrahydrofuran (100 mL) was added dropwise to the above solution, and the reaction was continued overnight. After the reaction was completed, 200 mL of water was added, and the mixture was extracted with ethyl acetate (150 ml * 3). The organic phase was removed by distillation under reduced pressure, and the residue was separated by silica gel column chromatography to obtain 7.2 g of a light yellow solid with a yield of 62.7%. HRMS(ESI)(m / z): 587.2845[M+H] + .

[0071] Synthesis of Compound 83b

[0072] Under nitrogen protection, a mixture of compound 83a (6.0 g, 10.2 mmol) and pyridine hydrochloride (60 g) was heated to 190 °C and reacted for 6 h. After cooling to room temperature, 200 mL of water was added, and the mixture was extracted with ethyl acetate (200 ml * 3). The organic phase was removed by distillation under reduced pressure, and the residue was separated by silica gel column chromatography to obtain 5.5 g of a light yellow solid with a yield of 93.9%. HRMS(ESI)(m / z): 572.2651[M+H] + .

[0073] Synthesis of Compound 83c

[0074] Take a 250ml three-necked flask, put 83b (5.0g, 8.73mmol), pyridine (1.38g, 17.5mmol) and dichloromethane (60ml), add trifluoromethanesulfonic anhydride (3.69g, 13.1mmol) dropwise under nitrogen protection in an ice bath, naturally warm to room temperature and stir overnight. After the reaction is completed, add water (100mL), extract with dichloromethane (100ml*3), evaporate the organic phase under reduced pressure, and separate the residue by silica gel column chromatography to obtain 5.2g of light yellow solid, with a yield of 84.5%. HRMS (ESI) (m / z): 705.2138 [M+H] + .

[0075] Synthesis of compound 83d

[0076] Under nitrogen protection, a mixture of 83c (5.0 g, 7.09 mmol), sodium tert-butoxide (1.02 g, 10.6 mmol), N-phenyl-o-phenylenediamine (1.56 g, 8.51 mmol), palladium acetate (0.16 g, 0.71 mmol), tri-tert-butylphosphine (0.14 g, 0.71 mmol) and toluene (500 mL) was heated to 120°C for overnight reaction. After the reaction, water (100 mL) was added, and the mixture was extracted with dichloromethane (100 ml*3). The organic phase was evaporated under reduced pressure, and the residue was separated by silica gel column chromatography to obtain 3.90 g of a light yellow solid with a yield of 74.4%. HRMS (ESI) (m / z): 739.3567 [M+H] + .

[0077] Synthesis of compound 83e

[0078] Under nitrogen protection, a mixture of compound 83d (2.9 g, 3.92 mmol), triethyl orthoformate (20 mL), ammonium hexafluorophosphate (3.84 g, 23.6 mmol) and acid salt (0.2 mL) was heated to 80°C, stirred for 24 hours, and filtered to obtain 1.8 g of product with a yield of 61.2%. HRMS (ESI) (m / z): 749.3383 [M-PF6] + .

[0079] Synthesis of complex 83

[0080] Under nitrogen protection, compound 83e (800 mg, 1.07 mmol), Pt(COD)Cl2 (379 mg, 1.28 mmol) and sodium acetate (263 mg, 3.2 mmol) were added to a tetrahydrofuran solution (20 mL) and reacted at 120°C for 24 hours. After the reaction, water (100 mL) was added, and the mixture was extracted with dichloromethane (100 ml*3). The organic phase was evaporated under reduced pressure, and the residue was separated by silica gel column chromatography to obtain 0.28 g of a light yellow solid with a yield of 27.7%. HRMS (ESI) (m / z): 942.2854 [M+H] + .

[0081] Example 3: Preparation of Complex 84

[0082]

[0083] Synthesis of compound 84a

[0084] Under nitrogen protection, a mixture of 57g (2.1g, 3.00mmol), sodium tert-butoxide (0.43g, 4.48mmol), N-(4-pyridyl) o-phenylenediamine (0.66g, 3.59mmol, synthesized according to US4855308), palladium acetate (0.067g, 0.30mmol), tri-tert-butylphosphine (0.06g, 0.30mmol) and toluene (30mL) was heated to 120°C for overnight reaction. After the reaction, water (100mL) was added, and the mixture was extracted with dichloromethane (100ml*3). The organic phase was evaporated under reduced pressure, and the residue was separated by silica gel column chromatography to obtain 1.50g of light yellow solid with a yield of 68.0%. HRMS (ESI) (m / z): 738.3567 [M+H] + .

[0085] Synthesis of compound 84b

[0086] Under nitrogen protection, a mixture of compound 84b (1.4 g, 1.9 mmol), triethyl orthoformate (20 mL), ammonium hexafluorophosphate (1.86 g, 11.4 mmol) and acid salt (0.2 mL) was heated to 80°C, stirred for 24 hours, and filtered to obtain 1.2 g of product with a yield of 70.8%. HRMS (ESI) (m / z): 748.3436 [M-PF6] + .

[0087] Synthesis of complex 84

[0088] Under nitrogen protection, compound 84b (900 mg, 1.01 mmol), Pt(COD)Cl2 (358 mg, 1.21 mmol) and sodium acetate (165 mg, 2.0 mmol) were added to a solution of tetrahydrofuran (20 mL), and the reaction was carried out at 120 °C for 24 hours. After the reaction was completed, water (100 mL) was added, and the mixture was extracted with dichloromethane (100 ml * 3). The organic phase was removed by distillation under reduced pressure, and the residue was separated by silica gel column chromatography to obtain 0.26 g of a light yellow solid with a yield of 27.7%. HRMS(ESI)(m / z): 941.2930[M+H] + 。

[0089] Examples 4-6

[0090] An organic light-emitting diode was fabricated using the luminescent material of the complex of the present invention. The device structure is shown in Figure 1 。

[0091] First, the transparent conductive ITO glass substrate 10 (with the anode 20 on it) was successively washed with a detergent solution, deionized water, ethanol, acetone, and deionized water, and then treated with oxygen plasma for 30 seconds.

[0092] Then, HATCN was evaporated on the ITO to prepare the hole injection layer 30.

[0093] Then, HT was evaporated on the hole injection layer to form a 40-nm-thick hole transport layer 40.

[0094] Then, the light-emitting layer 50 was evaporated on the hole blocking layer. The composition of the light-emitting layer was: platinum complex: BH (host material) = 6%: 100%. (The platinum complexes corresponding to Examples 4-6 were Complex 57, 83, and 84, respectively).

[0095] Then, a 40-nm-thick ET was evaporated on the light-emitting layer as the electron transport layer 60.

[0096] Finally, 1 nm of LiF was evaporated as the electron injection layer 70 and 100 nm of Al was evaporated as the device cathode 80.

[0097] Comparative Example 1:

[0098] Using the same preparation method, a device of Comparative Example 1 was prepared by using compound Ref-Pt to replace the platinum complex in the above example.

[0099] The structural formulas of HATCN, HT, BH, ET, and Ref-Pt in the device are as follows:

[0100]

[0101] The organic electroluminescent devices of Examples 4-6 and Comparative Example 1 at 10 mA / cm2 The device performance under the current density is listed in Table 1:

[0102] Table 1

[0103]

[0104] 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, emitting deep red light, and has a much higher luminous efficiency compared to the comparative molecule Ref-Pt. It is worth noting that the device lifetime of the organic light-emitting diode based on the complex of the present invention is significantly better than that of the complex material in the comparative example, and has good industrialization potential.

[0105] The above-mentioned various embodiments are only examples and are not used to limit the scope of the present invention. Without departing from the spirit of the present invention, 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 according to the idea of the present invention without creative labor. Therefore, the technical solutions that can be obtained by those skilled in the art through analysis, reasoning or partial research on the basis of the prior art should all be within the protection scope defined by the claims.

Claims

1. A tetradentate platinum complex based on a tetraarylethylene structure, which is a compound having the structure of formula (I): Wherein: X 1 -X 9 independently selected from CR 6 ; R 1 to R 6 are independently selected from: hydrogen, deuterium, halogen, cyano, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, or substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms; Ar 1 to Ar 5 is a five- or six-membered aromatic ring, or a five- or six-membered heteroaromatic ring; The heteroatom in the heteroaromatic ring is N; The substitution is substituted by a halogen or a C1-C4 alkyl group.

2. The platinum complex according to claim 1, R 1 to R 6 are each independently selected from: hydrogen, deuterium, halogen, cyano, substituted or unsubstituted alkyl having 1 to 6 carbon atoms, or substituted or unsubstituted cycloalkyl having 3 to 6 ring carbon atoms.

3. The platinum complex according to claim 2, R 1 to R 6 are each independently selected from: hydrogen, deuterium, halogen, C1-C4 alkyl, cyano, or a substituted or unsubstituted cycloalkyl having 3-6 ring carbon atoms.

4. The platinum complex according to claim 3, R 1 to R 6 are each independently selected from: hydrogen, deuterium, fluorine, methyl, isopropyl, isobutyl, tert-butyl, cyano, substituted or unsubstituted cyclopentyl, or substituted or unsubstituted cyclohexyl.

5. The platinum complex according to claim 4, wherein the general formula (I) is one of the following structures: R 1 to R 6 each independently selected from: hydrogen, deuterium, fluorine, methyl, tert-butyl, cyano, substituted or unsubstituted cyclopentyl, or substituted or unsubstituted cyclohexyl.

6. The platinum complex according to claim 5, Ar 1 , Ar 4 , Ar 5 is independently selected from a five-membered aromatic ring, a six-membered aromatic ring, a five-membered heteroaromatic ring or a six-membered heteroaromatic ring; Ar 2 , Ar 3 are independently selected from a six-membered aromatic ring or a six-membered heteroaromatic ring.

7. The platinum complex according to claim 6, wherein the general formula (I) is one of the following structures: wherein X 1 -X 3 、X 6 -X 9 are independently selected from CR 6 ; X 4 -X 5 are independently selected from CR 6 .

8. The platinum complex according to claim 6, wherein Ar 1 , Ar 4 , Ar 5 are selected from phenyl or pyridyl, Ar 2 , Ar 3 are each independently selected from six-membered aromatic rings, and X 1 -X 3 , X 6 -X 9 , X 4 -X 5 are independently selected from CR 6 .

9. The platinum complex according to claim 8, R 1 to R 6 each independently selected from: hydrogen, deuterium, fluorine or tert-butyl.

10. The platinum complex according to claim 1, which is one of the following compounds:

11. A precursor of the platinum complex according to any one of claims 1-10, and its structural formula is as follows: Wherein X 1 -X 9 , R 1 to R 5 , Ar 1 to Ar 5 are defined as described in any one of claims 1-10.

12. Use of the platinum complex according to any one of claims 1-10 in an organic light-emitting diode, an organic thin-film transistor, an organic photovoltaic device, a light-emitting electrochemical cell or a chemical sensor.

13. 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 1-10.

14. According to the organic light-emitting diode of claim 13, the layer where the platinum complex according to any one of claims 1-10 is located is the light-emitting layer.

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