Pinene pyridazine tetradentate platinum (II) and palladium (II) complexes based on intramolecular hydrogen bonds and preparation methods and applications thereof

Abstract

The invention discloses a pinene pyridazine tetradentate platinum (II) and palladium (II) complex based on intramolecular hydrogen bond and its preparation method and application, the complex is a class of chiral asymmetric tetradentate platinum (II) and palladium (II) complexes based on pinene pyridazine, and the general structural formula of the complex is a compound represented by the following formula (I) and (II): wherein R is N-carbazolyl, N-diphenylamine, N-phenothiazine, N-phenoxazine, N-dimethylacridinyl, 2,6-dimethyl substituted phenoxy, 2,6-diisopropyl substituted phenoxy, hexahydropyridine. The complex provided by the invention has the advantages of excellent photoelectric performance, stability, film forming property, solubility, etc., and is easy to prepare, low in cost, has aggregated luminescence and pressure-induced color performance, and can be applied to electroluminescent devices, pressure sensing or electrochromic device fields.

Description

Technical Field

[0001] The invention belongs to the technical field of optoelectronic materials, and relates to a pinene pyridazine tetradentate platinum (II) and palladium (II) complex based on intramolecular hydrogen bonds, and a preparation method and application thereof. Background Art

[0002] Phosphorescent materials are widely used in stress sensing, information storage, trademark anti-counterfeiting and light-emitting devices. At present, the research on phosphorescent metal complexes is mainly focused on Ir(III), Pt(II) and Pd(II). Among them, Pt(II) and Pd(II) complexes have square planar structures, and the ligands can be designed as bidentate, tridentate and tetradentate. These changes will significantly affect the photophysical properties of the complexes. In particular, rigid tetradentate ligands have attracted a lot of attention because the rigid structure can suppress the vibration and rotation around the metal ions, reduce non-radiative decay, and have good stability; secondly, in the visible region, their luminescent color can be changed by changing the structure of the ligand. Among them, Pd(II) complexes usually show a much weaker strong spin-orbit coupling effect and lack an effective radiative decay process from T1→S0. Therefore, most of them have a long decay lifetime at room temperature, which will lead to concentration quenching and a serious decrease in efficiency. However, by introducing a rigid group with large steric hindrance into the structure of the ligand, the problem of concentration quenching can be effectively improved, and the luminescence efficiency can be greatly increased.

[0003] Luminescent materials based on pyridazine are easy to synthesize and chemically modified, and have high electron affinity, luminescence efficiency, and excellent electrochemical and optical properties. Therefore, they are used in the fields of electronic devices such as OLED, OPV, OFET, and chemical biosensors. Pyridazine has strong acidity, so it is easy to be protonated, and the N on the pyridazine ring easily reacts with metals to form metal complexes. Pyridazines, which are highly π-electron deficient, are often introduced into π-conjugated organic compounds containing push-pull electron systems due to their strong electron-withdrawing properties. Compared with the commonly used platinum (II) complexes containing C^N=CH type main ligands, aromatic pyridazine C^N=N type cyclometal ligands have no steric hindrance of hydrogen atoms and are easy to coordinate. The bond distance between the coordinated nitrogen atom and the metal center atom is shortened, thereby increasing the bond energy. Compounds with this structure are easy to synthesize and have good thermal stability. They can be used in electroluminescent devices to extend the service life of the device. Based on the above viewpoints, using such a dinitrogen heterocycle as a ligand may synthesize electrophosphorescent materials with better performance. Pinene is a saturated aliphatic ring-containing compound with large steric hindrance. It has unique structural characteristics and very good solubility. It can be prepared from aromatic acetaldehyde and enal. It has attracted more and more attention in many fields such as material chemistry, supramolecular chemistry and organic catalysis. However, how to prepare a low-cost and high-luminescence efficiency complex material is an urgent problem to be solved. Summary of the invention

[0004] The purpose of the present invention is to develop a pinene pyridazine tetradentate platinum (II) and palladium (II) complex based on intramolecular hydrogen bonds, which is jointly regulated by intramolecular hydrogen bonds, donor-acceptor units and steric hindrance groups and has the advantages of excellent photoelectric properties, stability, film-forming properties, solubility, etc., and is simple to prepare and low in cost, and has aggregated luminescence and pressure-induced chromic properties, and its application in the field of electroluminescent devices, pressure sensors or electrochromic devices.

[0005] The present invention provides the following technical solutions:

[0006] In the first aspect, a pinene pyridazine tetradentate platinum (II) and palladium (II) complex based on intramolecular hydrogen bonding is provided, wherein the complex is a chiral asymmetric tetradentate platinum (II) and palladium (II) complex based on pinene pyridazine, and the general structural formula of the complex is a compound represented by the following formula (I) and (II):

[0007]

[0008] Wherein, R is one of N-carbazolyl, N-diphenylamino, N-phenothiazinyl, N-phenoxazinyl, N-dimethylacridinyl, 2,6-dimethyl substituted phenoxy, 2,6-diisopropyl substituted phenoxy, and hexahydropyridinyl,

[0009]

[0010] In a second aspect, a method for preparing a pinene pyridazine tetradentate platinum (II) and palladium (II) complex based on intramolecular hydrogen bonding according to the first aspect is provided, comprising the following steps:

[0011] Under nitrogen protection, potassium tetrachloroplatinate and pinenyl pyridazine ligands are dissolved in acetic acid, a catalyst is added, the mixture is reacted at room temperature in the dark, and then the temperature is raised to react to obtain a pinenyl pyridazine tetradentate platinum (II) complex as shown in formula (I);

[0012] Under nitrogen protection, palladium acetate and pinene pyridazine ligands are dissolved in acetic acid, a catalyst is added, and the reaction is carried out at room temperature in the dark, and then the temperature is raised to react to obtain a pinene pyridazine tetradentate palladium (II) complex as shown in formula (II).

[0013] Further, the method specifically includes the following steps:

[0014]

[0015] Dissolve dichloropyridazine and 3-methoxyphenylboronic acid in a mixed solution of an organic solvent and water in the presence of a palladium catalyst and a base, and reflux for 20 to 30 hours to obtain a methoxypyridazine derivative as shown in formula (1-1);

[0016] The methoxypyridazine derivative is dissolved in an organic solvent, a compound with an active group is added, and the mixture is reacted at 20 to 50° C. for 10 to 20 hours in the presence of a base to obtain a pyridazine derivative as shown in formula (1-2);

[0017] The pyridazine derivative is dissolved in an acid and refluxed for 40 to 50 hours to obtain a hydroxypyridazine derivative as shown in formula (1);

[0018] Dissolve m-bromoacetophenone in pyridine as a raw material, add iodine pyridine solution, and react at 100-120° C. for 5-10 hours to obtain a pyridinium salt derivative as shown in formula (2-1);

[0019] The pyridinium salt derivative, enal derivative and organic salt are dissolved in an organic solvent and refluxed for 10 to 20 hours to obtain a bromopinene derivative as shown in formula (2);

[0020] The hydroxypyridazine derivative and the bromopinene derivative are dissolved in an organic solvent, and reacted at 100 to 130° C. for 20 to 40 hours in the presence of cuprous iodide and a base to obtain a pinenepyridazine ligand as shown in formula (3);

[0021] Under nitrogen protection, a pinene pyridazine ligand as shown in formula (3) and potassium tetrachloroplatinate are dissolved in acetic acid, a catalyst is added, and the mixture is reacted at room temperature in the dark for 6 to 12 hours, and then the temperature is raised to 120 to 150° C. and reacted for 18 to 72 hours to obtain a pinene pyridazine tetradentate platinum (II) complex as shown in formula (I);

[0022] Under nitrogen protection, the pinene pyridazine ligand shown in formula (3) and palladium acetate are dissolved in acetic acid, a catalyst is added, and the reaction is carried out at room temperature in the dark for 6 to 12 hours, and then the temperature is raised to 120 to 150° C. and the reaction is carried out for 18 to 72 hours to obtain a pinene pyridazine tetradentate palladium (II) complex shown in formula (II).

[0023] Furthermore, the raw materials for preparing the methoxypyridazine derivatives shown in formula (1-1) are calculated by molar proportions as follows: 1 part of dichloropyridazine, 1 to 1.5 parts of 3-methoxyphenylboric acid, 0.03 to 0.05 parts of a catalyst, 3 to 5 parts of a base, 10 to 50 parts of a polar organic solvent, and 5 to 25 parts of water; the catalyst is one of tetrakistriphenylphosphine palladium, bis(triphenylphosphine)palladium dichloride, and 1,1'-bis(diphenylphosphino)ferrocenepalladium dichloride; the base is one of potassium carbonate, sodium carbonate, sodium tert-butoxide, and potassium tert-butoxide; the organic solvent is one of toluene, NN, dimethylformamide, tetrahydrofuran, and 1,4-dioxane.

[0024] Furthermore, the raw materials for preparing the pyridazine derivatives as shown in formula (1-2) are calculated by molar parts: 1 part of the methoxypyridazine derivatives as shown in formula (1-1), 10 to 50 parts of an organic solvent, 1 to 2 parts of a compound with an active group, and 3 to 10 parts of a base; the organic solvent is one of toluene, N,N-dimethylformamide, tetrahydrofuran, and 1,4-dioxane; the base is one of sodium hydride and n-butyl lithium; and R is one of N-carbazolyl, N-diphenylamine, N-phenothiazine, N-phenoxazine, N-dimethylacridinyl, 2,6-dimethyl substituted phenoxy, 2,6-diisopropyl substituted phenoxy, and hexahydropyridine.

[0025] Furthermore, the raw materials for preparing the hydroxypyridazine derivatives as shown in formula (1) are calculated by molar proportions as follows: 1 part of the pyridazine derivatives as shown in formula (1-2) and 40 to 100 parts of an acid; the acid is one of hydrobromic acid and acetic acid.

[0026] Furthermore, the raw materials for preparing the pyridinium salt derivatives as shown in formula (2-1) are calculated by molar proportions as follows: 1 part of m-bromoacetophenone, 10 to 50 parts of pyridine, and 0.5 to 1 part of iodine.

[0027] Furthermore, the raw materials for preparing the brominated pinene derivatives as shown in formula (2) are calculated by molar proportions as follows: 1 part of a pyridinium salt derivative as shown in formula (2-1), 1 to 1.5 parts of an aldehyde derivative, 2 to 3 parts of an organic salt, and 10 to 50 parts of an organic solvent; the organic salt is one of ammonium acetate, sodium acetate, and potassium acetate; the organic solvent is one of toluene, N,N-dimethylformamide, tetrahydrofuran, 1,4-dioxane, methanol, ethanol, and dimethyl sulfoxide.

[0028] Furthermore, the raw materials for preparing the pinene pyridazine ligand as shown in formula (3) are calculated by molar parts: 1 part of the hydroxypyridazine derivative as shown in formula (1), 1 part of the bromopinene derivative as shown in formula (2), 10-50 parts of an organic solvent, 0.01-0.1 parts of a catalyst cuprous iodide, and 0.1-10 parts of a base; the organic solvent is one of toluene, dimethyl sulfoxide, N,N-dimethylformamide, tetrahydrofuran, and 1,4-dioxane; the base is one of potassium carbonate, sodium carbonate, sodium tert-butoxide, potassium tert-butoxide, potassium phosphate, and cesium carbonate.

[0029] Furthermore, the raw materials for preparing the pinenyl pyridazine tetradentate platinum (II) complex as shown in formula (I) are calculated by molar parts: 1 part of the pinenyl pyridazine ligand shown in formula (3), 1.0-1.5 parts of potassium tetrachloroplatinate, 100-500 parts of acetic acid, and 0-5 parts of a catalyst; the catalyst is one of potassium acetate, sodium acetate, and ammonium acetate.

[0030] Furthermore, the raw materials for preparing the pinene pyridazine tetradentate palladium (II) complex as shown in formula (II) are calculated by molar parts: 1 part of the pinene pyridazine ligand as shown in formula (3), 1.0-1.5 parts of palladium acetate, 100-500 parts of acetic acid, and 0-5 parts of a catalyst; the catalyst is one of potassium acetate, sodium acetate, and ammonium acetate.

[0031] In a third aspect, there is provided an application of the pinene pyridazine tetradentate platinum (II) and palladium (II) complex based on intramolecular hydrogen bonds described in the first aspect, wherein the complex is applied as a light-emitting layer in an electroluminescent device due to its aggregation-induced phosphorescence property, or is applied in the fields of data recording, data storage, pressure sensor devices and pressure-sensitive devices due to its piezochromic property.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] (1) The present invention applies a pinene pyridazine compound having a stereoscopic structure to a tetradentate platinum (II) and palladium (II) complex, utilizes the intramolecular hydrogen bond formed between the CH on the pinene pyridine and the N atom on the pyridazine ring that does not participate in the coordination, and simultaneously introduces different substituents to modify the aromatic ring on the main ligand, thereby obtaining a tetradentate platinum (II) and palladium (II) complex phosphorescent material having a huge spatial steric hindrance structure and intramolecular hydrogen bonds; the tetradentate platinum (II) and palladium (II) complex phosphorescent material has a strong aggregated luminescent property, and is applied to the production of organic electroluminescent devices. The light-emitting layer can effectively inhibit the concentration quenching caused by the aggregation of molecules by utilizing the large spatial steric hindrance of the pinene structure, and its saturated aliphatic ring structure effectively regulates the solubility of the complex, thereby realizing a highly efficient phosphorescent device. At the same time, the pinene pyridazine tetradentate platinum (II) and palladium (II) complex phosphorescent material can change the stacking structure of molecules through external forces to achieve a change in the luminescent color due to the introduction of freely rotatable substituents. This type of material has good piezochromic properties and can be potentially used in data recording, data storage, pressure sensor devices, pressure-sensitive devices and other fields.

[0034] (2) The present invention constructs a molecular structure with intramolecular hydrogen bonds. With the enhancement of intramolecular hydrogen bonds and donor-acceptor electron effects, the luminescence efficiency of platinum (II) and palladium (II) complex phosphorescent materials is improved; at the same time, by introducing a large steric hindrance pinene structure containing a saturated aliphatic ring that wraps the platinum (II) and palladium (II) cores, an electron-deficient pyridazine unit and different donor structures on the ligand, an aggregation-induced luminescence effect is achieved, and the concentration quenching effect caused by the long life span is effectively suppressed; by utilizing the spatial effect of the introduced donor unit and the removal of hydrogen bonds by external force, a pressure-induced color blue shift effect is also achieved; in the present invention, halogen atoms are replaced by compounds containing active groups to further improve the solubility, hole transport ability and thermal stability of the complex. In addition, the introduction of these groups can produce a certain spatial effect, thereby reducing the interaction between the luminescence centers of the complex, reducing the self-quenching phenomenon of triplet excitons, and improving the luminescence performance of the material.

[0035] (3) The present invention utilizes the characteristic that pyridazine is easy to coordinate. Such complexes have high synthesis yield and are easy to purify. The electroluminescent device prepared by the preparation method provided by the present invention and the obtained pinene pyridazine tetradentate platinum (II) and palladium (II) complexes has high internal and external quantum yield, luminous brightness and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The ultraviolet absorption (UV) spectra of the phosphorescent platinum (II) complexes Pt-DQ and Pt-DQP and the platinum (II) complexes Pd-DQ and Pd-DQP in dichloromethane in Example 18.

[0037] Figure 2 2 is the fluorescence emission (PL) spectra of the phosphorescent platinum (II) complexes Pt-DQ and Pt-DQP in dichloromethane in Example 18.

[0038] Figure 3 1 is the emission (PL) spectrum of the phosphorescent platinum (II) complex Pd-DQ in a water / tetrahydrofuran (THF) mixture with different water content ratios in Example 18 (the percentage in the figure refers to the volume percentage of water in the water / tetrahydrofuran mixture).

[0039] Figure 4 1 is the emission (PL) spectrum of the phosphorescent platinum (II) complex Pd-DQP in a water / tetrahydrofuran (THF) mixture with different water content ratios in Example 18 (the percentage in the figure refers to the volume percentage of water in the water / tetrahydrofuran mixture).

[0040] Figure 5 This is the piezochromic effect of the phosphorescent platinum (II) complex Pd-DQ in Example 18.

[0041] Figure 6Density functional theory calculations for the phosphorescent platinum (II) complexes Pt-DQ and Pt-DQP and the platinum (II) complexes Pd-DQ and Pd-DQP in Example 19.

[0042] Figure 7 Cyclic voltammetry (CV) curves of the phosphorescent platinum (II) complexes Pt-DQ and Pt-DQP and the platinum (II) complexes Pd-DQ and Pd-DQP in dichloromethane solution in Example 20.

[0043] Figure 8 This is the device structure diagram and the molecular structural formulas of other materials used in the device in Example 21.

[0044] Fig. 9 The electroluminescence spectra (a), current density-voltage-brightness (b), brightness-current efficiency (c) and brightness-external quantum efficiency (d) curves of the electroluminescent device based on the phosphorescent platinum (II) complex Pd-DQ at doping concentrations of 10%, 15%, 20% and 100% in Example 21.

[0045] Fig.10 The electroluminescence spectra (a), current density-voltage-brightness (b), brightness-current efficiency (c) and brightness-external quantum efficiency (d) curves of the electroluminescent device based on the phosphorescent platinum (II) complex Pd-DQP at doping concentrations of 5%, 10%, 15%, 20% and 100% in Example 21. DETAILED DESCRIPTION

[0046] The invention discloses a pinene pyridazine tetradentate platinum (II) and palladium (II) complex based on intramolecular hydrogen bonding, and a preparation method and application thereof, wherein the tetradentate platinum (II) and palladium (II) complex modified by pinene and pyridazine is connected by oxygen atoms. The tetradentate phosphorescent platinum (II) and palladium (II) complex of the invention achieves the aggregation-induced luminescence effect by introducing a large sterically hindered pinene structure containing a saturated aliphatic ring that wraps the platinum (II) and palladium (II) core, an electron-deficient pyridazine unit and different electron-donating structures on the ligand, and effectively suppresses the concentration quenching effect caused by the long life. The intramolecular hydrogen bond is constructed, the luminescence efficiency of the phosphorescent material of the platinum (II) and palladium (II) complex is improved to the greatest extent, and the pressure-induced color change effect is also achieved. The preparation method is simple, the difference rate is high, and the complex is easy to purify; the obtained pinene-based pyridazine tetradentate platinum (II) and palladium (II) complex has high internal and external quantum yields, luminescence brightness and stability. The electroluminescent device of the present invention has a light-emitting layer, which is a pyridazine tetradentate platinum (II) and palladium (II) complex based on pinene, and is prepared by a vapor deposition film-making method under specific conditions. The device has low cost, simple operation, stable chemical properties, high luminous brightness and efficiency, and is helpful to realize a high-efficiency electroluminescent device.

[0047] In order to better understand the content of the present invention, the technical scheme of the present invention is further described below through specific examples and illustrations, including synthesis, property determination, titration experiment, etc. These implementation examples are only for the purpose of explaining the present invention and do not limit the present invention.

[0048] Example 1

[0049] Preparation of methoxypyridazine intermediate 3-chloro-6-(3-methoxyphenyl)pyridazine ClM-PP.

[0050] Weigh 3,6-dichloropyridazine (8.9 g, 60 mmol), 3-methoxyphenylboronic acid (10.9 g, 72 mmol), tetrakistriphenylphosphine palladium (2.4 g, 1.6 mmol), tetrabutylammonium bromide (1.9 g, 6 mmol) and potassium carbonate (24.8 g, 180 mmol) in a round-bottom flask, evacuate and fill with nitrogen three times, inject water (25 mL, 1388 mmol) and toluene (75 mL, 706 mmol) under nitrogen protection, and reflux at 120°C for 24 h. After the reaction is completed, cool to room temperature, extract with dichloromethane, collect the organic layer, dry, concentrate, and use V PE :V EA =20:1 column chromatography separation to obtain white solid 3-chloro-6-(3-methoxyphenyl)pyridazine ClM-PP6g in a yield of 45.5%. 1 H NMR (400MHz, CDCl3) δ7.82 (d, J = 9.0 Hz, 1H), 7.68 (s, 1H), 7.55 (t, J = 8.6 Hz, 2H), 7.42 (t, J = 8.0 Hz, 1H), 7.06 (d, J = 10.6 Hz, 1H), 3.90 (s, 3H).

[0051]

[0052] Example 2

[0053] Preparation of pyridazine intermediate 10-(6-(3-methoxyphenyl)pyridazin-3-yl)-10H-phenoxazine M-PPYP.

[0054] Weigh phenoxazine (4.6 g, 25 mmol) and put it into a reaction bottle. Vacuum and replace nitrogen 3-5 times. Place the reaction in an ice bath at 0°C. Add tetrahydrofuran (40 mL, 494 mmol) under nitrogen protection. At 0°C, drop 2.5 mol / L n-butyl lithium (11.3 mL, 28.9 mmol) into the reaction bottle. After 1 hour, drop 3-chloro-6-(3-methoxyphenyl) pyridazine ClM-PP (5.5 g, 25 mmol) in dry tetrahydrofuran solution into the reaction bottle. After the addition is complete, allow the reaction to warm to room temperature naturally and stir overnight at room temperature. Add saturated ammonium chloride solution to quench the reaction, extract with dichloromethane, dry, concentrate, and use V PE :V EA =20:1 column chromatography separation to obtain 5.0 g of light yellow solid 10-(6-(3-methoxyphenyl)pyridazin-3-yl)-10H-phenoxazine M-PPYP with a yield of 55.6%. 1 H NMR (400MHz, CDCl3) δ7.79 (d, J=9.3Hz, 1H), 7.72 (s, 1H), 7.52 (dd, J=16.3, 8.5Hz, 2H), 7.40 (t, J=8.0Hz, 1H), 7.31 (d, J=9.0Hz, 2H), 7.06–6.89 (m, 7H), 3.89 (s, 3H).

[0055]

[0056] Example 3

[0057] Preparation of hydroxypyridazine ligand 3-(6-(10H-benzoxazin-10-yl)pyridazin-3-yl)phenol OH-PPYP.

[0058] Weigh 10-(6-(3-methoxyphenyl)pyridazine-3-yl)-10H-phenoxazine M-PPYP (5 g, 13.6 mmol) in a round-bottom flask, inject hydrobromic acid (30 mL, 1084 mmol) and glacial acetic acid (100 mL, 890 mmol), and reflux at 120°C for 2 days. After the reaction is completed, cool to room temperature, add a large amount of ice water to the reaction solution, and a yellow-brown solid precipitates, which is filtered. Use V PE :V EA =3:1 column chromatography separation to obtain 4.4 g of yellow solid 3-(6-(10H-benzoxazin-10-yl)pyridazin-3-yl)phenol OH-PPYP in a yield of 91.6%. 1HNMR(400MHz,DMSO)δ9.75(s,1H),8.31(d,J=9.2Hz,1H),7.86(d,J=9.1Hz,1H),7 .68–7.54(m,2H),7.38(t,J=7.9Hz,1H),7.00–6.86(m,7H),6.75(d,J=9.1Hz,2H).

[0059]

[0060] Example 4

[0061] Preparation of brominated pinene ligand (6R,8R)-3-(3-bromophenyl)-pinene Br-DPTM.

[0062] Place m-bromoacetophenone (8.0 g, 40.0 mmol) and pyridine (40 mL, 497 mmol) in a three-necked flask, and slowly drop iodine (5.1 g, 20.0 mmol) in pyridine at 105°C. After the dropwise addition, keep warm for 5 h, cool to room temperature, filter, and vacuum dry to obtain 14.0 g of yellow solid 1-(2-(3-bromophenyl)-2-oxoethyl)pyridin-1-ium iodide Br-OPPI, with a yield of 87.9%. Place the above product Br-OPPI (4.1 g, 10.0 mmol), (1R)-(-)-myrtolide aldehyde (1.8 g, 12.0 mmol), anhydrous ammonium acetate (1.5 g, 20.0 mmol), and DMF (10 mL, 130 mmol) in a single-necked flask. React at 120°C for 12 h, and concentrate. Add water, extract with dichloromethane, wash the combined organic phases with water, wash with saturated brine, dry over anhydrous sodium sulfate, filter and concentrate to obtain a crude product, separate by column chromatography to obtain 2.3 g of yellow powder (6R, 8R)-3-(3-bromophenyl)-pinene Br-DPTM, with a yield of 70.0%. 1 H NMR (400MHz, CDCl3) δ8.24(s,1H),8.16(s,1H),7.91(d,J=8.3Hz,1H),7.52(s,2H),7.34(t,J=7.9Hz,1H), 3.05(s,2H),2.89(t,J=5.5Hz,1H),2.81–2.69(m,1H),2.35(s,1H),1.45(s,3H),1.28(s,1H),0.69(s,3H).

[0063]

[0064] Example 5

[0065] Preparation of pinene-based pyridazine primary ligand pinene phenoxypyridazine-10H-phenoxazine DTDMQ.

[0066] Weigh (6R, 8R)-3-(3-bromophenyl)-pinene Br-DPTM (327.0 mg, 1.0 mmol), 3-(6-(10H-phenoxazine-10-yl)pyridazine-3-yl)phenol OH-PPYP (353.0 mg, 1.0 mmol), CuI (19.0 mg, 0.1 mmol), cesium carbonate (977.0 mg, 3.0 mmol), 2-picolinic acid (0.3 g, 2.0 mmol) and place in a sealed tube, add 5 mL of DMSO (5 mL, 50 mmol) after nitrogen bubbling and deoxygenation, evacuate and fill with nitrogen three times, and react at 120°C for 24 hours. After the reaction is completed, extract with dichloromethane, dry with anhydrous sodium sulfate, and separate by developing agent column chromatography to obtain yellow powder pinene phenoxypyridazine-10H-phenoxazine DTDMQ0.4 g, with a yield of 66.7%. 1 H NMR(400MHz,DMSO)δ8.39(d,J=9.2Hz,1H),8.18(s,1H),7.95(s,1H),7.88(d ,J=10.9Hz,3H),7.80(s,2H),7.62(s,1H),7.53(s,1H),7.27(s,1H),7.15(s ,1H),6.95(d,J=14.7Hz,4H),6.89(s,2H),6.82(s,2H),3.01(s,2H),2.84(s ,1H),2.68(s,1H),2.28(s,1H),1.39(s,3H),1.16–1.12(m,1H),0.59(s,3H).

[0067]

[0068] Example 6

[0069] Preparation of complex Pt-DQ.

[0070] Weigh the main ligand pinene phenoxypyridazine-10H-phenoxazine DTDMQ (120.0 mg, 0.2 mmol) and K2PtCl4 (92.0 mg, 0.22 mmol) in a sealed tube, evacuate and fill with nitrogen. Blow nitrogen into acetic acid for 10 min, extract acetic acid (10 mL, 60 mmol) and add it to the sealed tube under nitrogen protection, stir at room temperature for 12 h, then heat to 120 ° C and react for 72 h. After the reaction is completed, pour the reaction solution into a large amount of ice water, and a red solid precipitates, which is filtered. Use V PE :V DCM =2:1 developing solvent for column chromatography separation to obtain 35.0 mg of deep red powder Pt-DQ with a yield of 22.0%. 1H NMR (400MHz, CDCl3) δ9.25(s,1H),8.22(d,J=9.1Hz,1H),7.86(d,J=9.0Hz,1H),7.66(s,1H),7.47(s,2H),7.34(s,4H) ,6.92(s,6H),6.78(s,2H),3.07(s,2H),2.61(s,1H),2.42(s,1H),2.31(s,1H),1.41(s,1H),1.32(s,3H),0.67(s,3H).

[0071]

[0072] Example 7

[0073] Preparation of complex Pd-DQ.

[0074] Weigh pinene phenoxypyridazine-10H-phenoxazine DTDMQ (120.0 mg, 0.2 mmol), Pd(OAc)2 (42.0 mg, 0.22 mmol), TBAB (8.0 mg, 0.1 mmol) in a sealed tube, evacuate, and fill with nitrogen. Blow nitrogen through acetic acid for 10 min, extract acetic acid (10 mL, 60 mmol) and add it to the sealed tube under nitrogen protection, stir at room temperature for 12 h, then heat to 120 ° C and react for 72 h. After the reaction is completed, pour the reaction solution into a large amount of ice water, and an orange-red solid precipitates, which is filtered. Use V PE :V DCM =2:1 developing solvent for column chromatography separation to obtain 42.0 mg of bright orange powder Pd-DQ with a yield of 34.8%. 1 H NMR (400MHz, CDCl3) δ8.92(s,1H),8.17(d,J=9.2Hz,1H),7.74(d,J=9.1Hz,1H),7.67(s ,1H),7.52–7.44(m,2H),7.36(d,J=7.0Hz,1H),7.31(d,J=7.3Hz,1H),7.27(d,J=2.9Hz ,2H),6.93(dd,J=9.1,5.8Hz,6H),6.77(dd,J=11.0,5.9Hz,2H),3.06(s,2H),2.63(d,J =5.7Hz,1H),2.49(t,J=5.5Hz,1H),2.30(s,1H),1.33(s,3H),1.25(s,1H),0.67(s,3H).

[0075]

[0076] Example 8

[0077] Preparation of pyridazine intermediate 6-(3-methoxyphenyl)-N,N-diphenylpyridazin-3-amine M-DPA.

[0078] Weigh diphenylamine (4.2 g, 25 mmol) and put it into a reaction bottle. Vacuum and replace nitrogen 3-5 times. Place the reaction in an ice bath at 0°C. Add tetrahydrofuran (40 mL, 494 mmol) under nitrogen protection. At 0°C, drop 2.5 mol / L n-butyl lithium (11.3 mL, 28.9 mmol) into the reaction bottle. After 1 hour, drop 3-chloro-6-(3-methoxyphenyl) pyridazine ClM-PP (5.5 g, 25 mmol) in dry tetrahydrofuran solution into the reaction bottle. After the addition is complete, allow the reaction to warm to room temperature naturally and stir overnight at room temperature. Add saturated ammonium chloride solution to quench the reaction, extract with dichloromethane, dry, concentrate, and use V PE :V EA =20:1 column chromatography separation to obtain 4.5 g of light yellow solid 6-(3-methoxyphenyl)-N,N-diphenylpyridazin-3-amine M-DPA with a yield of 51.1%. 1 H NMR (400MHz, CDCl3) δ7.97(d,J=7.1Hz,1H),7.57(ddd,J=8.6,2.2,1.2Hz,1H),7.43(t,J=2.2Hz,1H),7.38–7.27(m,5H) ,7.24(d,J=7.3Hz,1H),7.20–7.14(m,4H),7.04(tt,J=7.8,1.5Hz,2H),6.94(ddd,J=8.0,2.2,1.2Hz,1H),3.83(s,3H).

[0079]

[0080] Example 9

[0081] Preparation of hydroxypyridazine ligand 3-(6-(diphenylamino)pyridazin-3-yl)phenol OH-DPA.

[0082] Weigh 6-(3-methoxyphenyl)-N,N-diphenylpyridazine-3-amine M-DPA (5g, 14.2mmol) in a round-bottom flask, inject hydrobromic acid (30mL, 1084mmol) and glacial acetic acid (100mL, 890mmol), and reflux at 120℃ for 2 days. After the reaction is completed, cool to room temperature, add a large amount of ice water to the reaction solution, and a yellow-brown solid precipitates, which is filtered. Use V PE :V EA =3:1 column chromatography separation to obtain 4.2 g of yellow solid 3-(6-(diphenylamino)pyridazin-3-yl)phenol OH-DPA with a yield of 87.5%. 1H NMR (400MHz, CDCl3) δ8.80 (s, 1H), 8.07 (d, J = 7.3Hz, 1H), 7.47 (ddd, J = 8.4, 2.3, 1.2Hz, 1H), 7.35 –7.22(m,7H),7.20–7.14(m,4H),7.04(tt,J=7.8,1.5Hz,2H),6.81(ddd,J=8.2,2.2,1.1Hz,1H).

[0083]

[0084] Example 10

[0085] Preparation of pinene-based pyridazine primary ligand pinenephenoxypyridazine-10H-diphenylamine DTDA.

[0086] Weigh (6R, 8R)-3-(3-bromophenyl)-pinene Br-DPTM (327.0 mg, 1.0 mmol), 3-(6-(diphenylamino)pyridazin-3-yl)phenol OH-DPA (339.0 mg, 1.0 mmol), CuI (19.0 mg, 0.1 mmol), cesium carbonate (977.0 mg, 3.0 mmol), 2-picolinic acid (0.3 g, 2.0 mmol) and place in a sealed tube, add 5 mL of DMSO (5 mL, 50 mmol) after nitrogen bubbling and deoxygenation, evacuate and fill with nitrogen three times, and react at 120°C for 24 hours. After the reaction is completed, extract with dichloromethane, dry with anhydrous sodium sulfate, and separate by developing agent column chromatography to obtain yellow powder pinene phenoxypyridazine-10H-diphenylamine DTDA 0.4 g, with a yield of 68.3%. 1 H NMR (400MHz, CDCl3) δ8.22(s,1H),7.97(d,J=7.1Hz,1H),7.72(ddd,J=8.6,2.3,1.2Hz, 1H),7.61(ddd,J=8.6,1.9,1.2Hz,1H),7.53–7.40(m,4H),7.38(t,J=1.9Hz,1H),7.34– 7.26(m,4H),7.24(d,J=7.3Hz,1H),7.20–7.14(m,4H),7.08–7.00(m,4H),3.21–3.08(m ,2H),3.08–2.99(m,1H),2.31–2.19(m,1H),2.02–1.90(m,2H),0.97(d,J=16.5Hz,6H).

[0087]

[0088] Embodiment 11

[0089] Preparation of complex Pt-DA.

[0090] Weigh the main ligand pinene phenoxypyridazine-10H-diphenylamine DTDA (117.2 mg, 0.2 mmol) and K2PtCl4 (92.0 mg, 0.22 mmol) in a sealed tube, evacuate and fill with nitrogen. Add nitrogen to acetic acid for 10 min, extract acetic acid (10 mL, 60 mmol) and add it to the sealed tube under nitrogen protection, stir at room temperature for 12 h, then heat to 120 ° C and react for 72 h. After the reaction is completed, pour the reaction solution into a large amount of ice water, and a red solid precipitates, which is filtered. Use V PE :V DCM =2:1 developing solvent for column chromatography separation to obtain red powder Pt-DA25.0mg, yield 16.1%. 1 H NMR (400MHz, CDCl3) δ9.67 (d, J = 0.8Hz, 1H), 7.47 (s, 1H), 7.41–7.28 (m, 7H), 7. 16–7.09(m,4H),7.04(tt,J=7.7,1.5Hz,2H),6.96(d,J=7.5Hz,1H),6.88(s,2H) ,6.77(dd,J=7.6,1.2Hz,1H),6.72–6.68(m,2H),6.65–6.59(m,1H),3.11–2.90( m,3H),2.02–1.87(m,2H),1.78(dt,J=12.1,7.8Hz,1H),0.97(d,J=16.5Hz,6H).

[0091]

[0092] Example 12

[0093] Preparation of complex Pd-DA.

[0094] Weigh the main ligand pinene phenoxypyridazine-10H-diphenylamine DTDA (117.2 mg, 0.2 mmol), Pd(OAc)2 (42.0 mg, 0.22 mmol), TBAB (8.0 mg, 0.1 mmol) in a sealed tube, evacuate, and fill with nitrogen. Blow nitrogen through acetic acid for 10 min, extract acetic acid (10 mL, 60 mmol) and add it to the sealed tube under nitrogen protection, stir at room temperature for 12 h, and then heat to 120 ° C to react for 72 h. After the reaction is completed, pour the reaction solution into a large amount of ice water, and an orange-red solid precipitates, which is filtered. Use V PE :V DCM =2:1 developing solvent for column chromatography separation to obtain 30.0 mg of bright orange powder Pd-DA with a yield of 21.7%. 1H NMR (400MHz, CDCl3) δ9.49 (t, J=0.6Hz, 1H), 7.82 (dd, J=8.2, 1.4Hz, 1H), 7.60 (dd, J=8. 2,1.4Hz,1H),7.52–7.39(m,3H),7.34–7.25(m,5H),7.16–7.09(m,4H),7.05(t,J=1.5H z,1H),7.04–6.95(m,2H),6.72(dd,J=7.8,1.2Hz,1H),6.65(dd,J=7.8,1.2Hz,1H),3.1 1–2.91(m,3H),2.01–1.87(m,2H),1.78(dt,J=12.1,7.8Hz,1H),0.97(d,J=16.5Hz,6H).

[0095]

[0096] Example 13

[0097] Preparation of pyridazine intermediate 10-(6-(3-methoxyphenyl)pyridazin-3-yl)-9,9-dimethyl-9,10-dihydroacridine M-PYDD.

[0098] Weigh 9,10-dihydro-9,9-dimethylacridine (5.2 g, 25 mmol) and put it into a reaction bottle. Vacuum and replace nitrogen 3-5 times. Place the reaction in an ice bath at 0°C. Add tetrahydrofuran (40 mL, 494 mmol) under nitrogen protection. At 0°C, drop 2.5 mol / L n-butyl lithium (11.3 mL, 28.9 mmol) into the reaction bottle. After 1 hour, drop 3-chloro-6-(3-methoxyphenyl) pyridazine ClM-PP (5.5 g, 25 mmol) in dry tetrahydrofuran solution into the reaction bottle. After the addition is complete, allow the reaction to warm to room temperature naturally and stir overnight at room temperature. Add saturated ammonium chloride solution to quench the reaction, extract with dichloromethane, dry, concentrate, and use V PE :V EA =20:1 column chromatography separation to obtain 3.54 g of light yellow solid 10-(6-(3-methoxyphenyl)pyridazin-3-yl)-9,9-dimethyl-9,10-dihydroacridine M-PYDD with a yield of 36.2%. 1H NMR (400MHz, CDCl3) δ7.75(d,J=9.4Hz,2H),7.68(d,J=8.0Hz,2H),7.55(d,J=5.3Hz,1H),7.48(dd,J=10.9,8.6Hz,3H),7.40( t,J=8.0Hz,1H),7.27(s,1H),7.24(d,J=6.4Hz,1H),7.18(t,J=6.9Hz,2H),7.01(d,J=11.7Hz,1H),3.90(s,3H),1.60(s,6H).

[0099]

[0100] Embodiment 14

[0101] Preparation of hydroxypyridazine ligand 3-(6-(9,9-dimethylacridin-10(9H)-yl)pyridazin-3-yl)phenol OH-PYDD.

[0102] Weigh 10-(6-(3-methoxyphenyl)pyridazine-3-yl)-9,9-dimethyl-9,10-dihydroacridine M-PYDD (5 g, 12.7 mmol) in a round-bottom flask, inject hydrobromic acid (30 mL, 1084 mmol) and glacial acetic acid (100 mL, 890 mmol), and reflux at 120°C for 2 days. After the reaction is completed, cool to room temperature, add a large amount of ice water to the reaction solution, and a yellow-brown solid precipitates, which is filtered. Use V PE :V EA =3:1 column chromatography separation to obtain 4.5 g of yellow solid 3-(6-(9,9-dimethylacridin-10(9H)-yl)pyridazin-3-yl)phenol OH-PYDD with a yield of 93.7%. 1 H NMR(400MHz, CDCl3)δ8.80(s,1H),8.09(d,J=7.3Hz,1H),7.47(ddd,J=8.4,2.3,1.2Hz,1H),7.35– 7.22(m,5H),7.15–7.04(m,4H),7.01–6.94(m,2H),6.81(ddd,J=8.2,2.2,1.1Hz,1H),1.61(s,6H).

[0103]

[0104] Embodiment 15

[0105] Preparation of pinene-based pyridazine primary ligand pinene phenoxypyridazine-10H-dimethylacridine DPXP.

[0106] Weigh (6R,8R)-3-(3-bromophenyl)-pinene Br-DPTM (327.0 mg, 1.0 mmol), 3-(6-(9,9-dimethylacridin-10(9H)-yl)pyridazin-3-yl)phenol OH-PYDD (379.0 mg, 1.0 mmol), CuI (19.0 mg, 0.1 mmol), cesium carbonate (977.0 mg, 3.0 mmol), and 2-picolinic acid (0.3 g, 2.0 mmol) in a sealed tube, add 5 mL of DMSO (5 mL, 50 mmol) deoxygenated by nitrogen bubbling, evacuate and fill with nitrogen three times, and react at 120°C for 24 h. After the reaction was completed, the mixture was extracted with dichloromethane, dried over anhydrous sodium sulfate, and separated by developing agent column chromatography to obtain 0.4 g of yellow powder pinene phenoxypyridazine-10H-dimethylacridine DPXP with a yield of 64%. 1 H NMR (400MHz, CDCl3) δ7.94 (d, J=7.1Hz, 1H), 7.72 (ddd, J=8.6, 2.3, 1.2Hz, 1H), 7. 61(ddd,J=8.6,1.9,1.2Hz,1H),7.53–7.40(m,4H),7.38(t,J=1.9Hz,1H),7.32–7 .22(m,3H),7.15–7.06(m,4H),7.06–6.94(m,4H),3.21–3.08(m,2H),3.08–2.99( m,1H),2.31–2.19(m,1H),2.00–1.90(m,2H),1.61(s,6H),0.97(d,J=16.5Hz,6H).

[0107]

[0108] Example 16

[0109] Preparation of complex Pt-DQP.

[0110] Weigh the main ligand pinene phenoxy pyridazine-10H-dimethyl acridine DPXP (125.2 mg, 0.2 mmol) and K2PtCl4 (92.0 mg, 0.22 mmol) in a sealed tube, evacuate and fill with nitrogen. Add nitrogen to acetic acid for 10 min, extract acetic acid (10 mL, 60 mmol) and add it to the sealed tube under nitrogen protection, stir at room temperature for 12 h, and then heat to 120 ° C to react for 72 h. After the reaction is completed, pour the reaction solution into a large amount of ice water, and a red solid precipitates, which is filtered. Use V PE :V DCM =2:1 developing solvent for column chromatography separation to obtain red powder Pt-DQP20mg, yield 12.3%. 1H NMR(400MHz, CDCl3)δ9.67(d,J=0.8Hz,1H),7.41–7.33(m,3H),7.32–7.25(m,2H),7.15–7 .06(m,4H),7.04(d,J=7.5Hz,1H),6.97(ddd,J=14.1,6.3,1.3Hz,2H),6.91–6.81(m,3H),6 .77(dd,J=7.6,1.2Hz,1H),6.71(dd,J=7.5,1.1Hz,1H),6.65–6.59(m,1H),3.11–2.90(m, 3H),2.01–1.87(m,2H),1.78(dt,J=12.1,7.8Hz,1H),1.61(s,6H),0.97(d,J=16.5Hz,6H).

[0111]

[0112] Embodiment 17

[0113] Preparation of complex Pd-DQP.

[0114] Weigh the main ligand pinene phenoxypyridazine-10H-dimethylacridine DPXP (125.2 mg, 0.2 mmol), Pd(OAc)2 (42.0 mg, 0.22 mmol), TBAB (8.0 mg, 0.1 mmol) in a sealed tube, evacuate, and fill with nitrogen. Blow nitrogen through acetic acid for 10 min, extract acetic acid (10 mL, 60 mmol) and add it to the sealed tube under nitrogen protection, stir at room temperature for 12 h, and then heat to 120 ° C to react for 72 h. After the reaction is completed, pour the reaction solution into a large amount of ice water, and an orange-red solid precipitates, which is filtered. Use V PE :V DCM =2:1 developing solvent for column chromatography separation to obtain orange-red powder Pd-DQP50.0 mg, yield 40.7%. 1 H NMR (400MHz, CDCl3) δ8.84(s,1H),8.18(d,J=9.2Hz,1H),7.75(d,J=9.2Hz,1H) ,7.66(s,1H),7.55(d,J=5.8Hz,2H),7.51(d,J=7.6Hz,2H),7.36(dd,J=12.9,7 .0Hz,2H),7.28(d,J=3.4Hz,4H),7.19–7.09(m,4H),3.05(s,2H),2.60(s,1H), 2.39(s,1H),2.28(s,1H),1.72(s,6H),1.43(s,1H),1.26(s,3H),0.66(s,3H).

[0115]

[0116] Embodiment 18

[0117] The photophysical properties of platinum (II) complexes Pt-DQ and Pt-DQP and platinum (II) complexes Pd-DQ and Pd-DQP in solution were tested.

[0118] The UV-visible absorption and emission spectra of phosphorescent platinum (II) complexes Pt-DQ and Pt-DQP and platinum (II) complexes Pd-DQ and Pd-DQP are shown in the attached figure. Figure 1-Figure 4 The complexes Pt-DQ, Pt-DQP, Pd-DQ and Pd-DQP were prepared into 1×10 -4 mol / L dichloromethane (DCM) solution, transfer 2.5mL of complex Pt-DQ, Pt-DQP, Pd-DQ and Pd-DQP solution into a fluorescence cuvette, and test their UV-visible absorption and emission spectra. The experimental results show that the four complexes have strong absorption at 230nm-380nm, mainly because 1 π-π* transition, while the complex has weak absorption at 380nm-450nm, which is mainly due to the charge transfer from singlet metal to ligand ( 1 MLCT) and spin-forbidden triplet metal-to-ligand charge transfer ( 3 MLCT). When 380nm light is used as the excitation wavelength, Figure 2 It can be seen that the maximum emission peaks of the platinum (II) complexes Pt-DQ and Pt-DQP are both at 617nm, indicating that changing the active group will not change the luminescent color, and this type of material has good stability. Figure 3 and Figure 4The results show that the platinum (II) complexes Pd-DQ and Pd-DQP have the characteristics of aggregation-induced emission, and their emission spectra in water / THF mixed solutions with different volume ratios are tested. They are both insoluble in water, so when the volume ratio of water in the mixed solution gradually increases, aggregation occurs to enhance the emission. When the water / THF ratio in the solution reaches 90%, the color of the solution becomes significantly darker; and under 365nm ultraviolet light, when the solution is completely a good solvent, it emits almost no light or only very weak light. When the water ratio is 90%, strong luminescence can be observed, and the luminescence enhancement is greater than 1000 times. Since the distance between the ligand and the complex is far in the dilute THF state, the spatial torsion of the bond is relatively free, so it has no emission in the dilute good solvent. In the aggregated state, the interaction force between the molecules is enhanced, the torsion of the bond is restricted, and thus there is strong emission in the aggregated state. The maximum emission peaks of the complexes Pd-DQ and Pd-DQP in the aggregated luminescent state are both 635nm, and they also have excellent stability. Among them, the complex Pd-DQ showed a more obvious pressure-induced color blue shift effect. When the complex was ground, the luminescence had a blue shift phenomenon. This is because the intramolecular hydrogen bonds were destroyed under the action of external forces, and the conjugation degree of the molecular structure was reduced, resulting in a blue shift in the spectrum. Figure 5 shown.

[0119] Embodiment 19

[0120] Density functional theory calculations of platinum(II) complexes Pt-DQ and Pt-DQP and platinum(II) complexes Pd-DQ and Pd-DQP.

[0121] Density functional theory (DFT) calculations were performed on the complexes Pt-DQ, Pt-DQP, Pd-DQ and Pd-DQP using Gauss 06 to study the photophysical properties of these luminescent materials. Using the B3LYP method, for these four complexes, the HOMO distribution is mainly located on the central metal atom and phenyl-oxy-phenyl, while the LUMO is mainly confined to the electron acceptor pyridazine unit. Figure 6 The atomic orbital occupancy ratio distribution diagrams of the three materials are listed, and the HOMO energy levels of Pt-DQ, Pt-DQP, Pd-DQ and Pd-DQP are -4.87eV, -4.91eV, -5.03eV and -5.07eV, and the LUMO energy levels are -2.02eV, -2.08eV, -1.95eV and -2.03eV, respectively. The theoretical energy level differences of the four complexes are 2.85eV, 2.83eV, 3.08eV and 3.04eV, respectively.

[0122] Embodiment 20

[0123] The electrochemical properties of platinum (II) complexes Pt-DQ and Pt-DQP and platinum (II) complexes Pd-DQ and Pd-DQP were tested.

[0124] In order to study the HOMO and LUMO energy level states and charge carrier injection properties of Pt(II) and Pd(II) complexes, we used cyclic voltammetry (CV) to measure the oxidation potential of the system in dichloromethane solution with Ag / AgNO3 as the reference electrode. Figure 7 As shown, it can be seen that all complexes have oxidation peaks in the range of 1-1.5 V. And according to the oxidation potential and reduction potential of each complex, the corresponding HOMO energy level and LUMO energy level can be calculated, and then the energy gap E of platinum (II) complexes Pt-DQ and Pt-DQP and platinum (II) complexes Pd-DQ and Pd-DQP can be obtained. g (The difference between the HOMO energy level and the LUMO energy level) are 1.94eV, 2.07eV, 2.21eV and 2.39eV respectively.

[0125] Embodiment 21

[0126] Fabrication of organic electroluminescent devices.

[0127] The device of the present invention using the platinum (II) complex Pd-DQ and Pd-DQP as the light-emitting layer may include: the device structure is as follows Figure 8 As shown, HAT-CN (10nm) / TAPC (30nm) / TCTA (10nm) / MCP: x% Pd (25nm) / TmPyPb (35nm) / Liq (1nm) / Al, where HAT-CN is used as the hole injection layer of the device; TAPC and TCTA are used as hole transport layers, and they also have the function of adjusting energy level matching; MCP: x% Pd is the light-emitting layer, with MCP as the main material and doped with palladium (II) complexes of different concentrations; TmPyPb is used as the electron transport layer; Liq also plays a role in adjusting the energy level, and finally Al is used as the cathode of the device. The organic electroluminescent device with Pd-DQ as the light-emitting layer has a maximum current efficiency of 9.22cd / A, a power efficiency of 4.42lm / W, and an external quantum efficiency of 6.94%. In particular, its non-doped device still maintains a good efficiency of 3.91cd / A, 2.23lm / W and 5.76%. The electroluminescent spectrum, current density-voltage-brightness, brightness-current efficiency and brightness-external quantum efficiency curves of the electroluminescent device are shown in the attached figure. Fig. 9 Attached Fig.10The electroluminescence spectra, current density-voltage-brightness, brightness-current efficiency and brightness-external quantum efficiency curves of Pd-DQP at 5%, 10%, 15%, 20% and 100% doping concentrations are shown. It can be seen that the device doped with 10wt% has the best performance, with a maximum current efficiency of 28.59cd / A, a power efficiency of 20.84lm / W and an external quantum efficiency of 6.12%. The above data show that constructing this complex containing a large steric hindrance of pinene structure and DA structure can obtain a high-efficiency device.

[0128] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A pinene pyridazine tetradentate platinum (II) and palladium (II) complex based on intramolecular hydrogen bonding, characterized in that: The complex is a type of chiral asymmetric tetradentate platinum (II) and palladium (II) complex based on pinene pyridazines. The general structural formula of the complex is a compound represented by the following formulas (I) and (II): Among them, R is one of N-carbazolyl, N-diphenylamino, N-phenothiazinyl, N-phenoxazinyl, N-dimethylacridinyl, 2,6-dimethyl substituted phenoxy, 2,6-diisopropyl substituted phenoxy, and hexahydropyridinyl.

2. A method for preparing a pinenyl pyridazine tetradentate platinum (II) and palladium (II) complex based on intramolecular hydrogen bonding according to claim 1, characterized in that: The following steps are involved: Under nitrogen protection, potassium tetrachloroplatinate and pinenyl pyridazine ligands are dissolved in acetic acid, a catalyst is added, the mixture is reacted at room temperature in the dark, and then the temperature is raised to react to obtain a pinenyl pyridazine tetradentate platinum (II) complex as shown in formula (I); Under nitrogen protection, palladium acetate and pinene pyridazine ligands are dissolved in acetic acid, a catalyst is added, and the reaction is carried out at room temperature in the dark, and then the temperature is raised to react to obtain a pinene pyridazine tetradentate palladium (II) complex as shown in formula (II).

3. The method for preparing a pinenyl pyridazine tetradentate platinum (II) and palladium (II) complex based on intramolecular hydrogen bonding according to claim 2, characterized in that: The specific steps include: Dissolve dichloropyridazine and 3-methoxyphenylboronic acid in a mixed solution of an organic solvent and water in the presence of a palladium catalyst and a base, and reflux for 20 to 30 hours to obtain a methoxypyridazine derivative as shown in formula (1-1); The methoxypyridazine derivative is dissolved in an organic solvent, a compound with an active group is added, and the mixture is reacted at 20 to 50° C. for 10 to 20 hours in the presence of a base to obtain a pyridazine derivative as shown in formula (1-2); The pyridazine derivative is dissolved in an acid and refluxed for 40 to 50 hours to obtain a hydroxypyridazine derivative as shown in formula (1); Dissolve m-bromoacetophenone in pyridine as a raw material, add iodine pyridine solution, and react at 100-120°C for 5-10 hours to obtain a pyridinium salt derivative as shown in formula (2-1); The pyridinium salt derivative, enal derivative and organic salt are dissolved in an organic solvent and refluxed for 10 to 20 hours to obtain a bromopinene derivative as shown in formula (2); The hydroxypyridazine derivative and the bromopinene derivative are dissolved in an organic solvent, and reacted at 100 to 130° C. for 20 to 40 hours in the presence of cuprous iodide and a base to obtain a pinenepyridazine ligand as shown in formula (3); Under nitrogen protection, a pinene pyridazine ligand as shown in formula (3) and potassium tetrachloroplatinate are dissolved in acetic acid, a catalyst is added, and the mixture is reacted at room temperature in the dark for 6 to 12 hours, and then the temperature is raised to 120 to 150° C. and reacted for 18 to 72 hours to obtain a pinene pyridazine tetradentate platinum (II) complex as shown in formula (I); Under nitrogen protection, the pinene pyridazine ligand shown in formula (3) and palladium acetate are dissolved in acetic acid, a catalyst is added, and the reaction is carried out at room temperature in the dark for 6 to 12 hours, and then the temperature is raised to 120 to 150° C. and the reaction is carried out for 18 to 72 hours to obtain a pinene pyridazine tetradentate palladium (II) complex shown in formula (II).

4. The method for preparing a pinene pyridazine tetradentate platinum (II) and palladium (II) complex based on intramolecular hydrogen bonding according to claim 2, characterized in that: The raw materials for preparing the methoxypyridazine derivatives as shown in formula (1-1) are calculated by molar proportions as follows: 1 part of dichloropyridazine, 1 to 1.5 parts of 3-methoxyphenylboric acid, 0.03 to 0.05 parts of a catalyst, 3 to 5 parts of a base, 10 to 50 parts of a polar organic solvent, and 5 to 25 parts of water; the catalyst is one of tetrakistriphenylphosphine palladium, bis(triphenylphosphine)palladium dichloride, and 1,1'-bis(diphenylphosphino)ferrocenepalladium dichloride; the base is one of potassium carbonate, sodium carbonate, sodium tert-butoxide, and potassium tert-butoxide; the organic solvent is one of toluene, NN, dimethylformamide, tetrahydrofuran, and 1,4-dioxane.

5. The method for preparing a pinenyl pyridazine tetradentate platinum (II) and palladium (II) complex based on intramolecular hydrogen bonding according to claim 2, characterized in that: The raw materials for preparing the hydroxypyridazine derivatives as shown in formula (1) are calculated by molar proportions as follows: 1 part of the pyridazine derivatives as shown in formula (1-2) and 40 to 100 parts of an acid; the acid is one of hydrobromic acid and acetic acid.

6. The method for preparing a pinenyl pyridazine tetradentate platinum (II) and palladium (II) complex based on intramolecular hydrogen bonding according to claim 2, characterized in that: The raw materials for preparing the brominated pinene derivatives as shown in formula (2) are calculated by molar proportions as follows: 1 part of a pyridinium salt derivative as shown in formula (2-1), 1 to 1.5 parts of an aldehyde derivative, 2 to 3 parts of an organic salt, and 10 to 50 parts of an organic solvent; the organic salt is one of ammonium acetate, sodium acetate, and potassium acetate; the organic solvent is one of toluene, N,N-dimethylformamide, tetrahydrofuran, 1,4-dioxane, methanol, ethanol, and dimethyl sulfoxide.

7. The method for preparing a pinenyl pyridazine tetradentate platinum (II) and palladium (II) complex based on intramolecular hydrogen bonding according to claim 2, characterized in that: The raw materials for preparing the pinene pyridazine ligand as shown in formula (3) are calculated by molar parts: 1 part of the hydroxypyridazine derivative as shown in formula (1), 1 part of the bromopinene derivative as shown in formula (2), 10-50 parts of an organic solvent, 0.01-0.1 parts of a catalyst cuprous iodide, and 0.1-10 parts of a base; the organic solvent is one of toluene, dimethyl sulfoxide, N,N-dimethylformamide, tetrahydrofuran, and 1,4-dioxane; the base is one of potassium carbonate, sodium carbonate, sodium tert-butoxide, potassium tert-butoxide, potassium phosphate, and cesium carbonate.

8. The method for preparing a pinenyl pyridazine tetradentate platinum (II) and palladium (II) complex based on intramolecular hydrogen bonding according to claim 2, characterized in that: The raw materials for preparing the pinenyl pyridazine tetradentate platinum (II) complex as shown in formula (I) are calculated by molar parts: 1 part of the pinenyl pyridazine ligand as shown in formula (3), 1.0-1.5 parts of potassium tetrachloroplatinate, 100-500 parts of acetic acid, and 0-5 parts of a catalyst; the catalyst is one of potassium acetate, sodium acetate, and ammonium acetate.

9. The method for preparing a pinenyl pyridazine tetradentate platinum (II) and palladium (II) complex based on intramolecular hydrogen bonding according to claim 2, characterized in that: The raw materials for preparing the pinenyl pyridazine tetradentate palladium (II) complex as shown in formula (II) are calculated by molar parts: 1 part of the pinenyl pyridazine ligand as shown in formula (3), 1.0-1.5 parts of palladium acetate, 100-500 parts of acetic acid, and 0-5 parts of a catalyst; the catalyst is one of potassium acetate, sodium acetate, and ammonium acetate.

10. An application of the pinenyl pyridazine tetradentate platinum (II) and palladium (II) complex based on intramolecular hydrogen bonding according to claim 1, characterized in that: The complex is applied as a light-emitting layer to an electroluminescent device due to its aggregation-induced phosphorescence performance, or is applied to the fields of data recording, data storage, pressure sensor devices and pressure-sensitive devices due to its pressure-induced color change performance.

Images