Narrow-half-peak wide-width platinum complex phosphorescent material based on regulation and control of charge density of coumarin skeleton coordinated carbon atoms and preparation method thereof

Abstract

The invention discloses a narrow half-peak width platinum complex phosphorescent material based on regulation and control of charge density of coordination carbon atoms of a coumarin skeleton and a preparation method thereof, the structural general formula of the material is # imgabs0, regulation and control of the charge density of the coordination carbon atoms can be realized by a CN chelating ligand isomer synthesized by the coumarin skeleton, so that adjustment of MLCT components in an emission spectrum of a platinum complex is realized, and a narrow emission half-peak width and a wide emission spectrum are obtained. The requirement of the current BT.2020 wide color gamut is better met, and a core light-emitting material is provided for an OLED to meet ultrahigh-strength display; dual regulation and control of the emission color and the emission half-peak width of the platinum complex are achieved by regulating and controlling the charge density of coordinated carbon atoms in the coumarin-containing skeleton ligand, the variety of coordinated nitrogen heterocycles is further changed, comprehensive coverage from blue light to near-infrared emission color is achieved, the skeleton containing carbon, oxygen and hydrogen has high stability and rigidity, and the coumarin-containing skeleton ligand can be applied to the field of organic light emitting devices. The compound is an ideal skeleton for developing a practical high-performance narrow-half-peak-width platinum complex phosphorescent material, and has the characteristics of simple synthesis and easy functionalization.

Description

Technical Field

[0001] The invention relates to the technical field of organic electroluminescence, and in particular to a type of narrow half-width platinum complex phosphorescent material based on regulating the charge density of coumarin skeleton coordinated carbon atoms and a preparation method thereof. Background Art

[0002] Organic light-emitting diodes (OLEDs) have the advantages of self-luminescence, easy adjustment of luminous color, high contrast, wide viewing angle, fast response, high color rendering index, and flexible design. They are widely used in smart phones, high-end TVs, virtual reality and augmented reality, and have become an indispensable display technology in people's daily lives, showing great commercial value.

[0003] However, with the increasing demand for ultra-high-resolution displays, the International Telecommunication Union (ITU) has announced the color gamut standard (BT.2020) for the next generation of displays, which is 1.5 times the color gamut standard of the National Television System Committee (NTSC) of the United States. Organic electroluminescent materials are the core materials of OLEDs, which determine the emission wavelength, half-width, electroluminescent efficiency and other properties of the device. Therefore, in order to meet the BT.2020 standard, it is extremely important to develop electroluminescent materials with narrow half-width. Phosphorescent materials (mainly complexes containing metal atoms such as iridium and platinum) can emit light using triplet excitons generated by electrical excitation to achieve 100% internal quantum efficiency, and are the mainstream electroluminescent materials for current commercial applications. Therefore, the development of phosphorescent materials with narrow half-width is of great value for OLEDs to meet the requirements of the next generation of ultra-high-resolution displays.

[0004] Phosphorescent materials usually have a ligand center (LC) π-π * The mixed triplet emission characteristics of metal-to-ligand charge transfer (MLCT) show a wide emission spectrum (usually half-width>50nm). Therefore, the current narrow half-width phosphorescent materials are relatively rare, and the development of narrow half-width phosphorescent materials still faces great challenges. Compared with iridium complex phosphorescent materials, platinum complex phosphorescent materials usually show fewer MLCT emission characteristics, and have great potential in the development of narrow half-width phosphorescent materials, which is a good way for phosphorescent materials to meet the BT.2020 standard. At present, the invention patent US20160197291A1 applied by Professor Li Jian involves a series of tetradentate chelated platinum complex phosphorescent materials with narrow half-width, which is a good example. However, the synthesis of tetradentate platinum complexes is cumbersome, complex and extremely challenging, which seriously restricts the development of narrow half-width platinum complex phosphorescent materials. Therefore, it is very necessary to develop narrow half-width platinum complex phosphorescent materials with simple structure, easy synthesis and excellent performance.

[0005] In summary, the development of platinum complexes that are easy to synthesize, have narrow half-width and high electroluminescent properties has important practical value for phosphorescent materials to meet the needs of ultra-high-resolution display technology. Summary of the invention

[0006] In order to overcome the defects of the above-mentioned prior art, the purpose of the present invention is to provide a narrow half-width platinum complex phosphorescent material based on regulating the charge density of the coordinated carbon atoms of the coumarin skeleton and a preparation method, utilizing the characteristics of the coumarin skeleton structure such as high rigidity and easy synthesis and modification, and realizing simple regulation of the charge density of the ligand coordinated carbon atoms by changing the substitution position of the nitrogen heterocycle on the benzene ring of the coumarin skeleton, and then adjusting the MLCT transition component in the platinum complex by regulating the charge density of the coordinated carbon atoms, and finally obtaining an organic electroluminescent material that is easy to synthesize, has a narrow half-width and high electroluminescent efficiency.

[0007] In order to achieve the above object, the technical solution of the present invention is achieved as follows:

[0008] The narrow half-width platinum complex phosphorescent material based on regulating the charge density of the coumarin skeleton coordinated carbon atoms has the general structural formula:

[0009]

[0010] Wherein, Ar1 is selected from any of the following structures, R1 is any substituent selected from hydrogen, fluorine, methyl, methoxy, isopropyl or tert-butyl, and the substitution position and number on the nitrogen heterocyclic ring may vary:

[0011]

[0012] R1: -H, -F, -CH3, -OCH3, -i-Pr, -t-Bu……

[0013] Ar2 is selected from any of the following structures, R2, R3 are any substituents selected from hydrogen, fluorine, methyl, methoxy, isopropyl or tert-butyl; the asterisk indicates the carbon atom coordinated to the platinum center:

[0014] R2, R3: -H, -F, -CH3, -OCH3, -i-Pr, -t-Bu……

[0015] Among them, the O∧O ligand is a derivative of acetylacetone, taken from any of the following structures; R4 can be any substituent such as methyl, isopropyl, tert-butyl, thiophene, etc.:

[0016] R4: -CH3, -i-Pr, -t-Bu,

[0017] The method for preparing the narrow half-width platinum complex phosphorescent material based on regulating the charge density of the coumarin skeleton coordinated carbon atoms comprises the following steps:

[0018] Step 1: Synthesis of C^N organic ligands containing coumarin skeleton:

[0019] First, the bromophenol is completely dissolved in an acetonitrile solvent, and then anhydrous magnesium chloride, paraformaldehyde and triethylamine are added to the solution in sequence, and then the reaction is carried out at 70 to 90° C. for 9 to 18 hours to obtain an aldehyde-substituted phenol derivative;

[0020] Under nitrogen atmosphere, weigh the aldehyde-substituted phenol derivative and potassium acetate into a reaction device, then add acetic anhydride, and react the reaction solution at 160-180° C. for 6-10 hours to obtain a brominated coumarin skeleton;

[0021] Under nitrogen atmosphere, weigh bromocoumarin skeleton, bipyraclostrobin, Pd(dppf)Cl2, and potassium acetate into a reaction device, then add 1,4-dioxane solvent, and react at 90-110° C. for 16-24 h to obtain boric acid ester of coumarin skeleton;

[0022] Under nitrogen atmosphere, borate ester of coumarin skeleton, halide of nitrogen heterocycle, and Pd(PPh3)4 are weighed into a reaction device, and then THF and 2 mol / L potassium carbonate aqueous solution are added. The reaction solution is then heated at 80-110°C for 12-20 hours to obtain a C^N type organic ligand containing a coumarin skeleton.

[0023] Step 2: Synthesis of metal platinum dimer complex:

[0024] Under nitrogen atmosphere, a C^N type organic ligand containing a coumarin skeleton and potassium chloroplatinite are added into a reaction container in a ratio of (1.0-1.1):1, and then a mixed solvent of ethylene glycol ether and water that can completely dissolve the reactants is added into the reaction container. Then, the reaction is carried out at 70-90° C. for 10-18 hours. After the reaction is completed, 3-5 times the amount of saturated salt water of the reaction solution is added into the reaction container and stirred for 0.5-1 hour. The precipitated solid is collected by filtration, and the obtained solid is dried to obtain a reaction intermediate product, a metal platinum dimer complex;

[0025] Step 3: Synthesis of narrow half-width platinum complex phosphorescent materials based on regulating the charge density of coumarin skeleton-coordinated carbon atoms:

[0026] Under a nitrogen atmosphere, the metal platinum dimer complex obtained in the second step is completely dissolved in a dichloromethane solution, and then sodium acetylacetonate is added to the solution. After the reaction is completed, the reaction solution is concentrated to obtain a crude product, which is then purified on a chromatographic silica gel column or a homemade thin layer silica gel chromatography plate to obtain the final product, namely, an organic metal platinum complex luminescent material.

[0027] In the first step, the amount of anhydrous magnesium chloride is 1.0 to 2.0 times that of bromophenol, the amount of paraformaldehyde is 2 to 3 times that of bromophenol, and the amount of triethylamine is 2.5 to 4.0 times that of bromophenol.

[0028] In the first step, the amount of potassium acetate is 0.5 to 0.7 times that of the aldehyde-substituted phenol derivative, and 3 to 6 mL of acetic anhydride is added to 1 gram of the aldehyde-substituted phenol derivative.

[0029] In the first step, the amount of the diboric acid pinacol ester substance is 1.2 to 1.8 times that of the brominated coumarin skeleton, the amount of the Pd(dppf)Cl2 substance is 0.03 to 0.10 times that of the brominated coumarin skeleton, and the amount of the potassium acetate substance is 2.5 to 4.0 times that of the brominated coumarin skeleton.

[0030] In the first step, the amount of the halide substance is 0.80 to 1.10 times that of the coumarin skeleton borate, the amount of the Pd(PPh3)4 substance is 0.02 to 0.06 times that of the coumarin skeleton borate, the amount of the potassium carbonate substance in the 2 mol / L potassium carbonate aqueous solution is 2 to 6 times that of the coumarin skeleton borate, and the volume of THF is 2 to 5 times the volume of the potassium carbonate aqueous solution.

[0031] The volume ratio of ethylene glycol ethyl ether to water in the second step is (3-5):1.

[0032] In the third step, the amount of sodium acetylacetonate is 2.2 to 3.0 times that of the metal platinum dimer complex, and then the reaction is carried out at room temperature for 10 to 18 hours.

[0033] Compared with the prior art, the advantages of the present invention are:

[0034] (1) For the first time, the MLCT component in the emission characteristics of platinum complexes was regulated by adjusting the charge density of coordinated carbon atoms, achieving dual regulation of the luminescence color and half-width of the platinum complex. A new class of narrow half-width platinum complex phosphorescent materials was developed, overcoming the current dependence of narrow half-width phosphorescent materials on tetradentate platinum complexes, and providing new ideas for the development of narrow half-width phosphorescent materials.

[0035] (2) For the first time, a simple Perkin reaction was used to construct coumarin skeleton derivatives with different carbon atom positions that could be modified. This method has strong universality and can be used to construct coumarin skeleton derivatives containing different substituents, laying a good foundation for regulating the charge density of coordinated carbon atoms.

[0036] (3) The yield of the platinum complex dimer is increased by adjusting the solvent ratio and the reaction temperature; the auxiliary ligand acetylacetone is introduced under extremely mild conditions (sodium acetylacetonate, room temperature) to synthesize the final platinum complex, thereby avoiding the need to add strong base or high temperature when introducing the traditional acetylacetone auxiliary ligand to reduce the yield of the platinum complex; the goal of combining the two to significantly increase the final yield of the platinum complex is achieved.

[0037] In summary, by utilizing the characteristics of coumarin skeleton structure such as high rigidity, simplicity, easy synthesis and chemical modification, and strong luminescence properties, the MLCT component in the platinum complex can be adjusted by regulating the charge density of the coordinated carbon atoms, thereby achieving dual regulation of the luminescence color and half-peak width of the platinum complex. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Taking pyridine nitrogen heterocycle as an example, the synthesis route of the ligands required for Examples 1 to 4 of the narrow half-width platinum complex phosphorescent material based on regulating the charge density of the coordinating carbon atoms of the coumarin skeleton is provided in the present invention.

[0039] Figure 2 Taking pyridine nitrogen heterocycle as an example in the present invention, the synthesis routes of the complexes of Embodiment 1 to Embodiment 4 of the narrow half-width platinum complex phosphorescent material based on regulating the charge density of the coordinated carbon atoms of the coumarin skeleton are provided.

[0040] Figure 3 This is a room temperature ultraviolet absorption spectrum of the organometallic platinum complex PtC5 prepared in Example 1 of the present invention in a toluene solution.

[0041] Figure 4 This is a room temperature ultraviolet absorption spectrum of the organometallic platinum complex PtC6 prepared in Example 2 of the present invention in a toluene solution.

[0042] Figure 5 This is a room temperature ultraviolet absorption spectrum of the organometallic platinum complex PtC7 prepared in Example 3 of the present invention in a toluene solution.

[0043] Figure 6 This is a room temperature ultraviolet absorption spectrum of the organic metal platinum complex PtC8 prepared in Example 4 of the present invention in a toluene solution.

[0044] Figure 7 This is a room temperature photoluminescence spectrum of the organometallic platinum complex PtC5 prepared in Example 1 of the present invention in a toluene solution.

[0045] Figure 8 This is a room temperature photoluminescence spectrum of the organic metal platinum complex PtC6 prepared in Example 2 of the present invention in a toluene solution.

[0046] Fig. 9This is a room temperature photoluminescence spectrum of the organic metal platinum complex PtC7 prepared in Example 3 of the present invention in a toluene solution.

[0047] Fig.10 This is a room temperature photoluminescence spectrum of the organic metal platinum complex PtC8 prepared in Example 4 of the present invention in a toluene solution. DETAILED DESCRIPTION

[0048] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0049] Embodiment 1

[0050] The narrow half-peak width platinum complex phosphorescent material PtC5 based on regulating the charge density of the coumarin skeleton coordinated carbon atoms has the chemical formula: C 19 H 15 NO4Pt, molecular structure formula is:

[0051]

[0052] Refer to the attached Figure 1 and attached Figure 2 , the specific operation process is as follows:

[0053] Step 1

[0054]

[0055] (1) Weigh 6.34 g of m-bromophenol (36.64 mmol) into a 250 mL single-mouth bottle, add 200 mL of acetonitrile, then add 5.12 g of MgCl2 (55.06 mmol), 14.8 g of paraformaldehyde (73.56 mmol), and 12.8 mL of triethylamine (92.08 mmol), and reflux at 70-90 ° C for 12 h. After the reaction is completed, cool to room temperature, filter to remove insoluble matter, wash the filter cake with dichloromethane, and concentrate the filtrate. Separate and purify by silica gel column chromatography, with the mobile phase being petroleum ether / dichloromethane = 1 / 1. Finally, 2-bromo-6-hydroxybenzaldehyde and 4-bromo-2-hydroxybenzaldehyde are obtained as light yellow solids, 1.83 g and 5.02 g, respectively.

[0056] 2-Bromo-6-hydroxybenzaldehyde, yield: 24.8%; 1 H NMR (400MHz, CDCl3, δ): 11.12 (s, 1H), 9.86 (s, 1H), 7.41 (d, J=8.4Hz, 1H), 7.21–7.12 (m, 2H).

[0057] 4-Bromo-2-hydroxybenzaldehyde, yield 68.03%; 1H NMR (400MHz, CDCl3, δ): 11.11 (s, 1H), 9.86 (s, 1H), 7.41 (d, J=8.0Hz, 1H), 7.22–7.13 (m, 2H).

[0058]

[0059] (2) Weigh 3.19 g of 2-bromo-6-hydroxybenzaldehyde (15.85 mmol) and 0.93 g of potassium acetate (9.43 mmol) into a SCHLENK reaction tube. Add 15 mL of acetic anhydride under N2 atmosphere, and stir and reflux at 170°C for 8 h. After the reaction is completed, cool to room temperature, dilute with water, slowly add sodium carbonate aqueous solution under stirring until the solution is neutral, extract the neutralized liquid with dichloromethane, combine all organic phases, dry over anhydrous sodium sulfate, and remove the solvent by vacuum rotary evaporation. Separate and purify by silica gel column chromatography, with the mobile phase being petroleum ether / ethyl acetate = 12 / 1. Finally, 2.74 g of Br-C5 was obtained as a white solid with a yield of 76.8%.

[0060] 1 H NMR (400MHz, CDCl3, δ): 8.07 (d, J=10.0Hz, 1H), 7.51 (dd, J=8.0, 1.2Hz, 1H), 7.38 (t, J=8.2Hz, 1H), 7.29 (d, J=8.4Hz, 1H), 6.49 (d, J=10.0Hz).

[0061]

[0062] (3) 4.20 g Br-C5 (18.66 mmol), 7.11 g bis(pyridinium) borate (28.00 mmol), 0.41 g catalyst Pd(dppf)Cl2 (0.56 mmol), and 5.49 g potassium acetate (56.00 mmol) were weighed into a SCHLENK reaction tube. 100 mL 1,4-dioxane was added under N2 atmosphere, and the reaction was stirred at 100°C for 18 h. After the reaction was completed, the mixture was cooled to room temperature, and the solvent was removed by distillation under reduced pressure. The residual solid was redissolved in an appropriate amount of dichloromethane, and the palladium catalyst and inorganic matter were removed by rapid filtration using a short silica gel column. The filtrates were combined, and most of the solvent was removed by distillation under reduced pressure. The off-white C5-Bpin crude product (4.35 g) was obtained by precipitation with methanol. The crude product was used directly in the next step without further purification.

[0063]

[0064] (4) Weigh 1.00 g of 2-bromopyridine (6.33 mmol), 2.24 g of crude C5-Bpin (about 8.23 ​​mmol), and 0.22 g of Pd(PPh3)4 (0.19 mmol) in a SCHLENK reaction tube. Add 30 mL of tetrahydrofuran and 10 mL of 2M K2CO3 aqueous solution under N2 atmosphere, and stir at 100°C for 16 h. After the reaction is completed, cool to room temperature, dilute the reaction solution with saturated brine, extract the reaction solution with dichloromethane three times, combine the organic phases, and dry with anhydrous sodium sulfate. Remove the solvent by distillation under reduced pressure, and separate and purify the residual solid by silica gel column chromatography with dichloromethane as the mobile phase. Finally, 1.26 g of L-C5 was obtained as a white solid (yield: 89.5%).

[0065] 1 H NMR (400MHz, CDCl3, δ): 8.76 (dd, J=4.8, 0.8Hz, 1H), 8.20 (d, J=10.0Hz, 1H), 7.86 (td, J=7.8Hz, 1H), 7.60 (t, J=7.8Hz, 1H), 7 .56 (d, J=8.0Hz, 1H), 7.42 (d, J=2.4Hz, 1H), 7.40 (d, J=3.2Hz, 1H), 7.37 (ddd, J=7.6, 4.8, 1.2Hz, 1H), 6.42 (d, J=9.6Hz, 1H).

[0066] Step 2

[0067]

[0068] 0.20 g L-C5 (0.90 mmol) and 0.37 g potassium chloroplatinate (0.90 mmol) were weighed into a SCHLENK reaction tube, and 40 mL of a mixed solvent of ethylene glycol ether and water (v / v, 3 / 1) was added under N2 atmosphere, and the mixture was stirred at 90°C for 16 h. After the reaction system was cooled to room temperature, 150 mL of saturated brine was added to the reaction solution, and the solution was stirred for half an hour, and then the precipitated solid was collected by filtration, and the obtained solid was dried to obtain 0.37 g of chloro-bridged dimer solid, with a yield of 92.8%.

[0069] Step 3

[0070]

[0071] Under nitrogen atmosphere, 0.37 g of chloro-bridged dimer (0.41 mmol) was placed in a SCHLENK reaction tube, 30 mL of anhydrous dichloromethane was added, and then 0.11 g of sodium acetylacetonate (0.90 mmol) was added to the reaction solution, and the reaction was stirred at room temperature for 10 h. After the reaction was completed, the solvent was removed by pressure distillation, and the residual solid was separated and purified by thin layer chromatography, and the developing solvent was dichloromethane / petroleum ether = 1 / 2. Finally, 0.28 g of orange solid was obtained, and the yield was 60.9%.

[0072] 1 H NMR (400MHz, CDCl3, δ): 9.15 (dd, J=6.0, 1.6Hz, 1H), 8.40 (d, J=10.0Hz, 1H), 7.88 (td, J=7.6, 1.2Hz, 1H), 7.85 (d, J =8.8Hz, 1H), 7.80 (d, J = 8.4Hz, 1H), 7.22–7.18 (m, 2H), 6.45 (d, J = 10Hz, 1H), 5.49 (s, 1H), 2.03 (s, 3H), 2.02 (s, 3H).

[0073] Figure 3 This is a room temperature ultraviolet absorption spectrum of the organometallic platinum complex PtC5 prepared in Example 1 of the present invention in a toluene solution. The weak absorption band at about 370 to 500 nm indicates that PtC5 has more MLCT absorption components.

[0074] Figure 7 This is a room temperature photoluminescence spectrum of the organometallic platinum complex PtC5 prepared in Example 1 of the present invention in a toluene solution. The large shoulder peak at 590 nm is due to the fact that PtC5 has more MLCT absorption components, so its half-peak width is relatively wide (74 nm).

[0075] According to this embodiment and Figure 3 , Figure 7 It can be seen that compared with the prior art, the present invention is simple to synthesize and is easy to derive through a high-yield Suzuki coupling reaction, and more platinum complex phosphorescent materials based on coumarin skeletons are designed and synthesized. Although this embodiment has many MLCT transition components, a large MLCT emission peak at 590nm is generated, resulting in a wide emission peak of PtC5 (half-peak width 74nm); but the π-π * The emission peak of the transition component is narrow, and the MLCT component in the emission peak can be further reduced by changing the nitrogen heterocycle, which has great potential in obtaining narrow half-width platinum complex phosphorescent materials.

[0076] Embodiment 2

[0077] The narrow half-peak width platinum complex phosphorescent material PtC6 based on regulating the charge density of the coumarin skeleton coordinated carbon atoms has the chemical formula: C 19 H 15 NO4Pt, molecular structure formula is:

[0078]

[0079] Refer to the attached Figure 1 and attached Figure 2 , the specific operation process is as follows:

[0080] Step 1

[0081]

[0082] (1) The synthesis step of 5-bromo-2-hydroxybenzaldehyde in step 1 of this example is similar to step 1 (1) in example 1, so the synthesis method of step 1 (1) in example 1 can be referred to. Therefore, step 1 (1) in the specific operation process of this example is not described in detail here.

[0083] 5-Bromo-2-hydroxybenzaldehyde, yellow solid, yield 82.7%. 1 H NMR (400MHz, CDCl3, δ): 10.96 (s, 1H), 9.86 (s, 1H), 7.69 (s, 1H), 7.61 (d, J=8.8Hz, 1H), 6.92 (d, J=8.8Hz, 1H).

[0084]

[0085] (2) The synthesis steps of Br-C6 in this embodiment are similar to step 1 (2) in embodiment 1, so the synthesis method of step 1 (2) in embodiment 1 can be referred to. Therefore, step 1 (2) in the specific operation process of this embodiment is not described in detail here.

[0086] Br-C6, white solid, yield 81.4%. 1 H NMR (400MHz, CDCl3, δ): 7.65–7.60 (m, 3H), 7.22 (d, J=9.2Hz, 1H), 6.46 (d, J=9.6Hz, 1H).

[0087]

[0088] (3) The synthesis steps of C6-Bpin in this example are similar to step 1 (3) in Example 1, so the synthesis method of step 1 (3) in Example 1 can be referred to, so the specific operation process of step 1 (3) in this example is not described in detail here. In this example, C6-Bpin is still not carefully purified, and the off-white solid crude product directly precipitated is directly used in the next step of synthesis.

[0089]

[0090] (4) The synthesis steps of L-C6 in this embodiment are similar to step 1 (4) in embodiment 1, so the synthesis method of step 1 (4) in embodiment 1 can be referred to. Therefore, step 1 (4) in the specific operation process of this embodiment will not be described in detail here.

[0091] L-C6, white solid, yield 80.7%. 1 H NMR (400MHz, CDCl3, δ): 8.71 (d, J=4.8Hz, 1H), 8.19 (d, J=2.4Hz, 1H), 8.14 (dd, J=8.4Hz, 1H), 7.81 (d, J=9.2Hz, 1H), 7.79 (dd, J=7.2, 1.6Hz, 1H), 7.75 (d, J=8.0Hz, 1H), 7.43 (d, J=8.4Hz, 1H), 7.30–7.27 (m, 1H), 6.47 (d, J=9.6Hz, 1H).

[0092] Step 2

[0093]

[0094] The synthesis steps of the platinum dimer complex in this embodiment are similar to step 2 in embodiment 1, so the synthesis method of step 2 in embodiment 1 can be referred to, so step 2 in the specific operation process of this embodiment is not described in detail here. The obtained platinum dimer complex is a light yellow solid with a yield of 93.4%.

[0095] Step 3

[0096]

[0097] The synthesis steps of the target platinum complex in this embodiment are similar to step 3 in Example 1, so the synthesis method of step 3 in Example 1 can be referred to, so step 3 in the specific operation process in this embodiment is not described in detail here. In this embodiment, the developing solvent is dichloromethane / petroleum ether = 1 / 1, the yield is 62.1%, and the obtained platinum complex PtC6 is a light yellow solid.

[0098] 1H NMR (400MHz, CDCl3, δ): 8.96 (dd, J=6.0, 1.6Hz, 1H), 7.83 (td, J=8.0, 1.6Hz, 1H), 7.62 (d, J=9.6Hz, 1H), 7.57 (d, J=8.0Hz, 1H), 7.49 (s, 1H), 7.44 (s, 1H), 7.16 (td, J=6.0, 1.2Hz, 1H), 6.31 (d, J=9.4Hz, 1H), 5.49 (s, 1H), 2.02 (s, 3H), 2.01 (s, 1H).

[0099] Figure 4 This is a room temperature ultraviolet absorption spectrum of the organometallic platinum complex PtC6 prepared in Example 2 of the present invention in a toluene solution. The weak absorption band at about 370 to 450 nm indicates that PtC6 has less MLCT absorption components.

[0100] Figure 8 This is a room temperature photoluminescence spectrum of the organometallic platinum complex PtC6 prepared in Example 2 of the present invention in a toluene solution. The smaller shoulder peak at 520 nm is due to the fact that PtC6 has fewer MLCT absorption components, so its half-peak width is narrower (48 nm).

[0101] According to this embodiment and Figure 4 , Figure 8 It can be seen that compared with the prior art, the present invention is simple to synthesize and is easy to derive through a high-yield Suzuki coupling reaction, and more narrow-spectrum platinum complex phosphorescent materials are designed and synthesized. The MLCT transition component of this embodiment is relatively small, and the MLCT emission peak at 520nm is small. Its half-peak width is mainly composed of the π-π at 486nm. * The transition emission peak determines the emission peak of PtC6, so the emission peak is narrow (half-peak width 48nm, less than 50nm). And by changing the nitrogen heterocycle, the MLCT component in the emission peak can be further reduced and the luminescent color can be adjusted, which has great advantages in obtaining color-adjustable narrow half-peak width platinum complex phosphorescent materials.

[0102] Embodiment 3

[0103] The narrow half-peak width platinum complex phosphorescent material PtC7 based on regulating the charge density of the coumarin skeleton coordinated carbon atoms has the chemical formula: C 19 H 15 NO4Pt, molecular structure formula is:

[0104]

[0105] Refer to the attached Figure 1 and attached Figure 2 , the specific operation process is as follows:

[0106] (1) The organic metal iridium complex phosphorescent material containing a coumarin skeleton finally synthesized in this embodiment shares the reaction process of step 1 (1) in embodiment 1 with that in embodiment 1. Since step 1 (1) in embodiment 1 can simultaneously obtain two products, 2-bromo-6-hydroxybenzaldehyde and 4-bromo-2-hydroxybenzaldehyde, step 1 (1) in the specific operation process of this embodiment is omitted here, and step 1 (2) in the operation process is directly listed. However, it does not mean that the operation process of the organic metal iridium complex phosphorescent material containing a coumarin skeleton shown in this embodiment does not include the above step 1 (1).

[0107]

[0108] (2) The synthesis steps of Br-C7 in this embodiment are similar to step 1 (2) in embodiment 1, so the synthesis method of step 1 (2) in embodiment 1 can be referred to. Therefore, step 1 (2) in the specific operation process of this embodiment is not described in detail here.

[0109] Br-C7, white solid, yield: 81.7%; 1 H NMR (400MHz, CDCl3, δ): 7.67 (d, J=9.6Hz, 1H), 7.52 (d, J=1.6Hz, 1H), 7.42 (dd, J=8.2, 2.0Hz, 1H), 7.35 (d, J=8.0Hz, 1H), 6.44 (d, J=9.6Hz).

[0110]

[0111] (3) The synthesis steps of C7-Bpin in this embodiment are similar to step 1 (3) in Example 1, so the synthesis method of step 1 (3) in Example 1 can be referred to, so the specific operation process of step 1 (3) in this embodiment is not described in detail here. In this embodiment, C7-Bpin is still not carefully purified, and the off-white solid crude product directly precipitated is directly used in the next step of synthesis.

[0112]

[0113] (4) The synthesis steps of L-C7 in this embodiment are similar to step 1 (4) in embodiment 1, so the synthesis method of step 1 (4) in embodiment 1 can be referred to. Therefore, step 1 (4) in the specific operation process of this embodiment will not be described in detail here.

[0114] L-C7, white solid, yield 81.8%. 1H NMR (400MHz, CDCl3, δ): 8.74 (dd, J=4.8, 0.8Hz, 1H), 7.98 (dd, J=8.0, 1.6Hz, 1H), 7.95 (s, 1H), 7. 81 (m, 2H), 7.75 (d, J=9.2Hz, 1H), 7.58 (d, J=8.0Hz, 1H), 7.31 (m, 1H), 6.46 (dd, J=9.4, 1.4Hz, 1H).

[0115] Step 2

[0116]

[0117] The synthesis steps of the platinum dimer complex in this embodiment are similar to step 2 in embodiment 1, so the synthesis method of step 2 in embodiment 1 can be referred to, so step 2 in the specific operation process of this embodiment is not described in detail here. The obtained platinum dimer complex is an orange solid with a yield of 92.2%.

[0118] Step 3

[0119]

[0120] The synthesis steps of the target platinum complex in this embodiment are similar to step 3 in Example 1, so the synthesis method of step 3 in Example 1 can be referred to, so step 3 in the specific operation process in this embodiment is not described in detail here. The developing solvent in this embodiment is dichloromethane / petroleum ether=2 / 3, and the yield is 60.3%. The obtained platinum complex PtC7 is an orange solid.

[0121] 1 H NMR (400MHz, CDCl3, δ): 9.06 (d, J=5.6Hz, 1H), 7.91 (t, J=6.0Hz, 1H), 7.77 (d, J=9.6Hz, 1H), 7.68 (d, J=8.4Hz, 1 H), 7.64 (s, 1H), 7.41 (s, 1H), 7.28–7.21 (m, 1H), 6.41 (d, J=9.6Hz, 1H), 5.51 (s, 1H), 2.05 (s, 3H), 2.03 (s, 3H).

[0122] Figure 5 This is a room temperature ultraviolet absorption spectrum of the organometallic platinum complex PtC7 prepared in Example 3 of the present invention in a toluene solution. The weak absorption band at about 370 to 480 nm indicates that PtC7 has more MLCT absorption components.

[0123] Fig. 9This is a room temperature photoluminescence spectrum of the organometallic platinum complex PtC7 prepared in Example 3 of the present invention in a toluene solution. The large shoulder peak at 606 nm is due to the fact that PtC7 has more MLCT absorption components, so its half-peak width is relatively wide (59 nm).

[0124] According to this embodiment and Figure 5 , Fig. 9 It can be seen that compared with the prior art, the present invention is simple to synthesize and is easy to derive through a high-yield Suzuki coupling reaction to design and synthesize a variety of platinum complex phosphorescent materials based on coumarin skeletons. Although this embodiment has more MLCT transition components, it produces a larger MLCT emission peak at 606nm, resulting in a wider emission peak of PtC7 (half-peak width 59nm); but the π-π * The emission peak of the transition component is extremely narrow, and the MLCT component in the emission peak can be further reduced by changing the nitrogen heterocycle, which has great potential in obtaining narrow half-width platinum complex phosphorescent materials.

[0125] Embodiment 4

[0126] The narrow half-peak width platinum complex phosphorescent material PtC8 based on regulating the charge density of the coumarin skeleton coordinated carbon atoms has the chemical formula: C 19 H 15 NO4Pt, molecular structure formula is:

[0127]

[0128] See attached Figure 1 and attached Figure 2 , the specific operation process is as follows:

[0129] Step 1

[0130]

[0131] (1) The synthesis step of 5-bromo-2-hydroxybenzaldehyde in step 1 of this example is similar to step 1 (1) in example 1, so the synthesis method of step 1 (1) in example 1 can be referred to. Therefore, step 1 (1) in the specific operation process of this example is not described in detail here.

[0132] 3-Bromo-2-hydroxybenzaldehyde, yellow solid, yield 88.3%. 1 H NMR (400MHz, CDCl3, δ): 11.61 (s, 1H), 9.85 (d, J=2.0Hz, 1H), 7.78 (dd, J=7.6, 1.6Hz, 1H), 7.55 (dd, J=7.8, 1.6Hz, 1H), 6.94 (td, J=7.8, 2.0Hz, 1H).

[0133]

[0134] (2) The synthesis steps of Br-C8 in this embodiment are similar to step 1 (2) in embodiment 1, so the synthesis method of step 1 (2) in embodiment 1 can be referred to. Therefore, step 1 (2) in the specific operation process of this embodiment will not be described in detail here.

[0135] Br-C8, white solid, yield: 80.3%. 1 H NMR (400MHz, CDCl3, δ): 7.75 (d, J=8.0Hz, 1H), 7.68 (d, J=9.2Hz, 1H), 7.44 (dd, J=7.6, 1.2Hz, 1H), 7.16 (t, J=7.8Hz, 1H), 6.45 (d, J=9.6Hz, 1H).

[0136]

[0137] (3) The synthesis steps of C8-Bpin in this embodiment are similar to step 1 (3) in Example 1, so the synthesis method of step 1 (3) in Example 1 can be referred to, so the specific operation process of step 1 (3) in this embodiment is not described in detail here. In this embodiment, C8-Bpin is still not carefully purified, and the off-white solid crude product directly precipitated is directly used in the next step of synthesis.

[0138]

[0139] (4) The synthesis steps of L-C8 in this embodiment are similar to step 1 (4) in Example 1, so the synthesis method of step 1 (4) in Example 1 can be referred to. Therefore, step 1 (4) in the specific operation process of this embodiment will not be described in detail here.

[0140] L-C8, white solid, yield 84.2%. 1 H NMR (400MHz, CDCl3, δ): 8.75 (dd, J=4.8, 0.8Hz, 1H), 8.11 (dd, J=8.0, 1.6Hz, 1H), 8.03 (d, J=8.0Hz, 1H), 7.83 (td, J=7.8, 1.6Hz, 1H) , 7.79 (d, J=9.6Hz, 1H), 7.54 (dd, J=7.6, 1.6Hz, 1H), 7.41 (t, J=7.6Hz, 1H), 7.31 (ddd, J=7.6, 4.8, 0.8Hz, 1H), 6.47 (d, J=9.6Hz, 1H).

[0141] Step 2

[0142]

[0143] The synthesis steps of the platinum dimer complex in this embodiment are similar to step 2 in embodiment 1, so the synthesis method of step 2 in embodiment 1 can be referred to, so step 2 in the specific operation process of this embodiment is not described in detail here. The obtained platinum dimer complex is an orange solid with a yield of 93.4%.

[0144] Step 3

[0145]

[0146] The synthesis steps of the target platinum complex in this embodiment are similar to step 3 in Example 1, so the synthesis method of step 3 in Example 1 can be referred to, so step 3 in the specific operation process in this embodiment is not described in detail here. The developing solvent in this embodiment is dichloromethane / petroleum ether = 1 / 1, and the yield is 61.1%. The obtained platinum complex PtC8 is a yellow solid.

[0147] 1 H NMR (400MHz, CDCl3, δ): 9.08 (d, J=6.0, 1.6Hz, 1H), 8.75 (dt, J=8.4, 1.2Hz, 1H), 7.92 (td, J=8.0, 1.6Hz, 1H), 7.71 (d, J=9.2Hz, 1H), 7.61 (d, J=8.0Hz, 1H), 7.24 (d, J=8.0Hz, 1H), 7.20 (td, J=6.0, 1.2Hz, 1H), 6.34 (d, J=9.2Hz, 1H), 5.50 (s, 1H), 2.04 (s, 6H).

[0148] Figure 6 This is a room temperature ultraviolet absorption spectrum of the organometallic platinum complex PtC8 prepared in Example 4 of the present invention in a toluene solution. The weak absorption band at about 370 to 450 nm indicates that PtC8 has very few MLCT absorption components.

[0149] Fig.10 This is a room temperature photoluminescence spectrum of the organometallic platinum complex PtC8 prepared in Example 4 of the present invention in toluene solution. The very small shoulder peak at 540 nm is due to the fact that PtC8 has very few MLCT absorption components, so its half-peak width is very narrow (13 nm).

[0150] According to this embodiment and Figure 6 , Fig.10It can be seen that compared with the prior art, the present invention is simple to synthesize and is easy to derive through a high-yield Suzuki coupling reaction, and more platinum complex phosphorescent materials with extremely narrow emission spectra are designed and synthesized. The MLCT transition component of this embodiment is very small, the MLCT emission peak at 540nm is very small, and the π-π * The transition emission peak is extremely narrow, so the emission peak of PtC8 is extremely narrow (the half-peak width is only 13nm). At the same time, the MLCT component in the emission peak can be further reduced and the luminescence color can be adjusted by changing the nitrogen heterocycle, which has great application potential in obtaining color-adjustable and extremely narrow half-peak width platinum complex phosphorescent materials.

Claims

1. A narrow half-width platinum complex phosphorescent material based on regulating the charge density of coumarin skeleton coordinated carbon atoms, characterized in that: Its general structural formula is: Wherein, Ar1 is selected from any of the following structures, R1 is any substituent selected from hydrogen, fluorine, methyl, methoxy, isopropyl or tert-butyl, and the substitution position and number on the nitrogen heterocyclic ring may vary: R1: -H, -F, -CH3, -OCH3, -i-Pr, -t-Bu…… Ar2 is selected from any of the following structures, R2, R3 are any substituents selected from hydrogen, fluorine, methyl, methoxy, isopropyl or tert-butyl; the asterisk indicates the carbon atom coordinated to the platinum center: R2, R3: -H, -F, -CH3, -OCH3, -i-Pr, -t-Bu…… The O^O ligand is a derivative of acetylacetone, taken from any of the following structures; R4 can be any substituent such as methyl, isopropyl, tert-butyl, thiophene, etc.: R4: -CH3, -i-Pr, -t-Bu, 2. The method for preparing a phosphorescent material having a narrow half-width platinum complex based on regulating the charge density of coumarin skeleton coordinated carbon atoms according to claim 1, characterized in that: The following steps are involved: Step 1: Synthesis of C^N organic ligands containing coumarin skeleton: First, the bromophenol is completely dissolved in an acetonitrile solvent, and then anhydrous magnesium chloride, paraformaldehyde and triethylamine are added to the solution in sequence, and then the reaction is carried out at 70 to 90° C. for 9 to 18 hours to obtain an aldehyde-substituted phenol derivative; Under nitrogen atmosphere, weigh the aldehyde-substituted phenol derivative and potassium acetate into a reaction device, then add acetic anhydride, and react the reaction solution at 160-180° C. for 6-10 hours to obtain a brominated coumarin skeleton; Under nitrogen atmosphere, weigh bromocoumarin skeleton, bipyraclostrobin, Pd(dppf)Cl2, and potassium acetate into a reaction device, then add 1,4-dioxane solvent, and react at 90-110° C. for 16-24 h to obtain the boric acid ester of the coumarin skeleton; Under nitrogen atmosphere, borate ester of coumarin skeleton, halide of nitrogen heterocycle, and Pd(PPh3)4 are weighed into a reaction device, and then THF and 2 mol / L potassium carbonate aqueous solution are added. The reaction solution is then heated at 80-110°C for 12-20 hours to obtain a C^N type organic ligand containing a coumarin skeleton. Step 2: Synthesis of metal platinum dimer complex: Under nitrogen atmosphere, a C^N type organic ligand containing a coumarin skeleton and potassium chloroplatinite are added into a reaction container in a ratio of (1.0-1.1):1, and then a mixed solvent of ethylene glycol ether and water that can completely dissolve the reactants is added into the reaction container. Then, the reaction is carried out at 70-90° C. for 10-18 hours. After the reaction is completed, 3-5 times the amount of saturated salt water of the reaction solution is added into the reaction container and stirred for 0.5-1 hour. The precipitated solid is collected by filtration, and the obtained solid is dried to obtain a reaction intermediate product, a metal platinum dimer complex; Step 3: Synthesis of narrow half-width platinum complex phosphorescent materials based on regulating the charge density of coumarin skeleton-coordinated carbon atoms: Under a nitrogen atmosphere, the metal platinum dimer complex obtained in the second step is completely dissolved in a dichloromethane solution, and then sodium acetylacetonate is added to the solution. After the reaction is completed, the reaction solution is concentrated to obtain a crude product, which is then purified on a chromatographic silica gel column or a homemade thin layer silica gel chromatography plate to obtain the final product, namely, an organic metal platinum complex luminescent material.

3. The method for preparing a narrow half-width platinum complex phosphorescent material based on regulating the charge density of coumarin skeleton coordinated carbon atoms according to claim 2, characterized in that: In the first step, the amount of anhydrous magnesium chloride is 1.0 to 2.0 times that of bromophenol, the amount of paraformaldehyde is 2 to 3 times that of bromophenol, and the amount of triethylamine is 2.5 to 4.0 times that of bromophenol.

4. The method for preparing a narrow half-width platinum complex phosphorescent material based on regulating the charge density of coumarin skeleton coordinated carbon atoms according to claim 2, characterized in that: In the first step, the amount of potassium acetate is 0.5 to 0.7 times that of the aldehyde-substituted phenol derivative, and 3 to 6 mL of acetic anhydride is added based on 1 gram of the aldehyde-substituted phenol derivative.

5. The method for preparing a narrow half-width platinum complex phosphorescent material based on regulating the charge density of coumarin skeleton coordinated carbon atoms according to claim 2, characterized in that: In the first step, the amount of the diboric acid pinacol ester substance is 1.2 to 1.8 times that of the brominated coumarin skeleton, the amount of the Pd(dppf)Cl2 substance is 0.03 to 0.10 times that of the brominated coumarin skeleton, and the amount of the potassium acetate substance is 2.5 to 4.0 times that of the brominated coumarin skeleton.

6. The method for preparing a phosphorescent material having a narrow half-width platinum complex based on regulating the charge density of coumarin skeleton coordinated carbon atoms according to claim 2, characterized in that: In the first step, the amount of the halide substance is 0.80 to 1.10 times that of the coumarin skeleton borate, the amount of the Pd(PPh3)4 substance is 0.02 to 0.06 times that of the coumarin skeleton borate, the amount of the potassium carbonate substance in the 2 mol / L potassium carbonate aqueous solution is 2 to 6 times that of the coumarin skeleton borate, and the volume of THF is 2 to 5 times the volume of the potassium carbonate aqueous solution.

7. The method for preparing a phosphorescent material having a narrow half-width platinum complex based on regulating the charge density of coumarin skeleton coordinated carbon atoms according to claim 2, characterized in that: The volume ratio of ethylene glycol ethyl ether to water in the second step is (3-5):

1.

8. The method for preparing a phosphorescent material having a narrow half-width platinum complex based on regulating the charge density of coumarin skeleton coordinated carbon atoms according to claim 2, characterized in that: In the third step, the amount of sodium acetylacetonate is 2.2 to 3.0 times that of the metal platinum dimer complex, and then the reaction is carried out at room temperature for 10 to 18 hours.

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