O^C^N^N-TYPE TETRADENTATE PLATINUM (II) COMPLEX, PREPARATION METHOD THEREFOR, AND APPLICATION THEREOF

Abstract

The present invention relates to the preparation and application of an O∧C∧N∧N tetradentate platinum (II) complex. The complex of the present invention has a structure as shown in Formula (I) below. Compared with a reference device, the organic light-emitting device prepared by the present invention has better performance improvement, and the novel O∧C∧N∧N tetradentate platinum (II) complex has great application value. The tetradentate platinum (II) complex involved in the present invention is based on a carbazole framework, and has a large π-conjugated rigid planar structure, which can greatly reduce non-radiative energy dissipation such as intramolecular rotation and vibration, and is conducive to improving the luminous efficiency and performance of the platinum (II) complex. The O∧C∧N∧N tetradentate platinum (II) complex metal organic material prepared by the present invention has great application values in organic light-emitting diodes, and is used as a phosphorescent doping material to produce a red light OLED device with high luminous efficiency.

##STR00001##

Claims

1. An O∧C∧N∧N tetradentate platinum (II) complex, having a structure as shown in Formula (I) below: ##STR00025## wherein R.sub.1-R.sub.17 are independently selected from hydrogen, deuterium, sulfur, halogen, hydroxy, acyl, alkoxy, acyloxy, amino, nitro, acylamino, cyano, carboxyl, styryl, aminocarbonyl, carbamoyl, benzylcarbonyl, aryloxy, silicyl, diarylamino, saturated alkyl containing 1-30 C atoms, unsaturated alkyl containing 1-20 C atoms, substituted or unsubstituted aryl containing 5-30 C atoms, substituted or unsubstituted heteroaryl containing 5-30 C atoms, or adjacent R.sub.1-R.sub.17 are mutually linked to form a ring via a covalent bond; the substitution refers to a substitution by deuterium, halogen, cyano, nitro, amino, C1-C8 alkyl; and heteroatom in the heteroaryl is atoms N, O and S.

2. The complex according to claim 1, wherein the R.sub.1-R.sub.17 are independently selected from hydrogen, halogen, amino, nitro, cyano, silicyl, diarylamino, saturated alkyl containing 1-10 C atoms, aryl substituted by halogen or one or more C1-C4 alkyl and containing 5-20 C atoms or unsubstituted aryl containing 5-20 C atoms, heteroaryl substituted by halogen or one or more C1-C4 alkyl and containing 5-20 C atoms or unsubstituted heteroaryl containing 5-20 C atoms, or adjacent R.sub.1-R.sub.16 are mutually linked to form a ring via a covalent bond; and the halogen is F, Cl, and Br.

3. The complex according to claim 2, having a structure as shown in Formula (II) below: ##STR00026## wherein R.sub.1′-R.sub.5′ are independently selected from hydrogen, halogen, silicyl, diarylamino, saturated alkyl containing 1-10 C atoms, aryl substituted by halogen or one or more C1-C4 alkyl and containing 5-20 C atoms or unsubstituted aryl containing 5-20 C atoms, heteroaryl substituted by halogen or one or more C1-C4 alkyl and containing 5-20 C atoms or unsubstituted heteroaryl containing 5-20 C atoms, or adjacent R.sub.1′-R.sub.5′ are mutually linked to form a ring via a covalent bond; and the halogen is F, Cl, and Br.

4. The complex according to claim 3, wherein in 5 groups of the R.sub.1′-R.sub.5′, 0-3 groups independently represent diarylamino, aryl substituted by halogen or one to three C1-C4 alkyl and containing 5-10 C atoms or unsubstituted aryl containing 5-10 C atoms, heteroaryl substituted by halogen or one to three C1-C4 alkyl and containing 5-10 C atoms or unsubstituted heteroaryl containing 5-10 C atoms; and other groups independently represent hydrogen, halogen or saturated alkyl containing 1-8 C atoms, and the halogen is F and Cl.

5. The complex according to claim 4, wherein in the 5 groups of the R.sub.1′-R.sub.5′, 0-3 groups independently represent diarylamino, C1-C4 alkyl substituted or unsubstituted phenyl, pyridyl, and carbazolyl; and other groups independently represent hydrogen, fluorine and saturated alkyl containing 1-4 C atoms.

6. The complex according to claim 1, having one of the following structures: ##STR00027## ##STR00028## ##STR00029## ##STR00030## ##STR00031## ##STR00032## ##STR00033## ##STR00034## ##STR00035## ##STR00036##

7. A precursor of the complex of any one of claims 1-6, namely, a ligand, having a structural formula as shown in Formula (III) below: ##STR00037## wherein R.sub.1-R.sub.17 are independently selected from hydrogen, deuterium, sulfur, halogen, hydroxy, acyl, alkoxy, acyloxy, amino, nitro, acylamino, cyano, carboxyl, styryl, aminocarbonyl, carbamoyl, benzylcarbonyl, aryloxy, silicyl, diarylamino, saturated alkyl containing 1-30 C atoms, unsaturated alkyl containing 1-20 C atoms, substituted or unsubstituted aryl containing 5-30 C atoms, substituted or unsubstituted heteroaryl containing 5-30 C atoms, or adjacent R.sub.1-R.sub.17 are mutually linked to form a ring via a covalent bond, wherein the substitution refers to a substitution by deuterium, halogen, cyano, nitro, amino, C1-C8 alkyl; and heteroatom in the heteroaryl is atoms N, O and S.

8. The precursor according to claim 7, having a preferred structural formula as shown in Formula (IV) below: ##STR00038## wherein R.sub.1′-R.sub.5′ are independently selected from hydrogen, halogen, silicyl, diarylamino, saturated alkyl containing 1-10 C atoms, aryl substituted by halogen or one or more C1-C4 alkyl and containing 5-20 C atoms or unsubstituted aryl containing 5-20 C atoms, heteroaryl substituted by halogen or one or more C1-C4 alkyl and containing 5-20 C atoms or unsubstituted heteroaryl containing 5-20 C atoms, or adjacent R.sub.1′-R.sub.5′ are mutually linked to form a ring via a covalent bond; and the halogen is F, Cl, and Br.

9. A synthesis method of the complex according to claim 3, comprising the following steps: subjecting carbazole derivatives S1 and S2 to Suzuki reaction to obtain a substrate S3; subjecting the S3 and S4 to Buchwald reaction to obtain an S5; demethylating the S5 under the action of a pyridine hydrochloride to obtain a ligand S6, and reacting the S6 with K.sub.2PtCl.sub.4 to obtain a target product P; a reaction formula thereof is as follows: ##STR00039##

10. An application of the complex of any one of claims 1-6 in an OLED luminescent device.

11. The application according to claim 10, wherein the complex of any one of claims 1-6 is applied to the OLED luminescent device by heat deposition, spin coating and ink-jet printing in a form of layer.

12. The application according to claim 10, wherein the complex of any one of claims 1-6 serves as a phosphorescent doping material having a photon emission effect in a light-emitting layer.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0034] FIG. 1 is a structure diagram showing an organic light-emitting device of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

[0035] The present invention will be further described specifically in combination with the examples below.

[0036] The preparation method of the above complex includes the following steps: [0037] as shown below, subjecting carbazole derivatives S1 and S2 to Suzuki reaction to obtain a substrate S3; subjecting the S3 and S4 to Buchwald reaction to obtain an S5; demethylating the S5 under the action of a pyridine hydrochloride to obtain a ligand S6, and reacting the S6 with K.sub.2PtCl.sub.4 to obtain a target product P.

##STR00016##

[0038] The present invention will be further described specifically in combination with the examples below.

[0039] Initial substrates and solvents related in the compound synthesis of the present invention are purchased from Energy Chemical, J&K Chemicals, aladdin and other suppliers known well by a person skilled in the art.

[0040] Example 1:

##STR00017##

[0041] Synthesis route:

##STR00018##

[0042] Synthesis of the compound 3: 9.84 g (40.0 mmol) compound 1, 6.69 g (1.1 eq., 44.0 mmol) compound 2, 11.04 g (2.0 eq., 80 mmol) potassium carbonate and 924 mg (0.02 eq., 0.8 mmol) Pd(PPh.sub.3).sub.4 were taken and added to a three-necked flask, vacuumized and fed with nitrogen for replacement repeatedly, then infused with 120 mL dioxane and 40 mL water, and heated up to 105° C. The system was subjected to reaction for 12 h under the protection of nitrogen, then cooled to room temperature; a proper amount of water and ethyl acetate were added for extraction, organic phases were collected and dried by anhydrous magnesium sulfate, after removing the solvent by rotary evaporation, a n-hexane/ethyl acetate system column chromatography (mobile phase n-hexane/ethyl acetate=10:1) was performed, thus obtaining 10.0 g of a white solid with a yield of 92% and a purity of 99.5%. Theoretical values of mass spectrometry (ESI.sup.+) ([M−H].sup.−) C.sub.19H.sub.14NO:272.11; measured value: 272.13.

[0043] Synthesis of the compound 5:5.47 g (20 mmol) compound 3, 5.17 g (1.1 eq., 22 mmol) compound 4, 225 g (0.02 eq., 1 mmol) palladium acetate, 0.20 g (0.04 eq., 2 mmol) tri-tert-butylphosphine, and 4.5 g (2.0 eq., 0.04 mol) potassium tert-butoxide were taken and added to a flask, and added with 100 mL toluene, and heated for reflux reaction for 8 h under the protection of nitrogen. After stopping the reaction, the system was cooled to room temperature and subjected to rotary evaporation to remove the solvent; a proper amount of water and ethyl acetate were added for extraction, organic phases were collected and dried, after removing the solvent by rotary evaporation, a flash silica gel column (mobile phase n-hexane/ethyl acetate=10:1) was used for separation, thus obtaining 7.3 g of a target product compound 5 with a yield of 85% and a purity of 99.9%. Theoretical values of mass spectrometry (ESI.sup.−)([M−H].sup.−) C.sub.29H.sub.21N.sub.3O:426.16; measured value: 426.13.

[0044] Synthesis of the compound 6:4.27 g (10 mmol) compound 5 and 50 g pyridine hydrochloride were taken and heated up to 200° C. for reaction for 8 h under the protection of nitrogen. After stopping the reaction, a proper amount of water and ethyl acetate were added for extraction, organic phases were collected and dried, after removing the solvent by rotary evaporation, a flash silica gel column (mobile phase n-hexane/ethyl acetate=15:1) was used for separation and methanol was used for recrystallization, thus obtaining 63.3 g of a target product compound 6 with a yield of 80% and a purity of 99.9%.Theoretical values of mass spectrometry (ESI.sup.−)([M−H].sup.−) C.sub.28H.sub.18N.sub.3O:412.15; measured value:412.10.

[0045] Synthesis of the compound TM-1: 2.06 g (5.0 mmol) compound 6, 400 mg (0.25 eq., 1.25 mmol) tetrabutylammonium bromide and 2.49 mg (1.2 eq., 6 mmol) potassium tetrachlorplatinate were taken and dissolved into 150 mL acetic acid, and vacuumized and fed nitrogen for replacement for several times, stirred and heated up to 130° C. for reaction for 12 h. After stopping the reaction, the system was cooled to remove the solvent by rotary evaporation; a proper amount of water and ethyl acetate were added for extraction, organic phases were collected and dried by anhydrous magnesium sulfate, then subjected to rotary evaporation to remove the solvent, and a n-hexane/ethyl acetate system column chromatography was performed, and the obtained coarse product was sublimated in vacuum, thus obtaining 1.67 g of a red solid with a total yield of 55% and a purity of 99.9%. Theoretical values of mass spectrometry (ESI.sup.+)([M+H].sup.+) C.sub.28H.sub.18N.sub.3OPt:607.10; measured value: 607.15.

[0046] Example 2:

##STR00019##

[0047] The preparation method of TM-3 is the same as the synthetic route of TM-1, and the only difference is that the compound 1 is replaced with the compound 7. The compound 7 has the following molecular formula:

##STR00020##

[0048] Example 3:

##STR00021##

[0049] The preparation method of TM-5 is the same as the synthetic route of TM-1, and the only difference is that the compound 1 is replaced with the compound 7, and the compound 4 is replaced with the compound 8. The compound 8 has the following molecular formula:

##STR00022##

[0050] The application example of the compound in the present invention is as follows: [0051] ITO/TAPC (60 nm)/TCTA:Pt(II)(40 nm)/TmPyPb(30 nm)/LiF(1 nm)/Al (80 nm)

[0052] Preparation mode of the device: [0053] A transparent anode, indium tin oxide (ITO, 20)(10Ω/sq) glass substrate was subjected to ultrasonic cleaning with acetone, ethanol and distilled water successively, and then subjected to plasma treatment with oxygen gas for 5 min.

[0054] The ITO substrate was then mounted on a substrate holder of a vacuum gas-phase evaporation equipment. In the evaporation equipment, the system pressure was controlled 10.sup.−6 torr.

[0055] Afterwards, a hole transport layer (30) material TAPC having a thickness of 60 nm was evaporated on the ITO substrate.

[0056] A light-emitting layer material (40) TCTA having a thickness of 40 nm was then evaporated, where the platinum (II) complex having a mass fraction of 10% was doped.

[0057] A hole transport layer (50) material TmPyPb having a thickness of 30 nm was then evaporated.

[0058] LiF having a thickness of 1 nm was then evaporated as an electron injection layer (60).

[0059] Finally, Al having a thickness of 80 nm was evaporated as a cathode (70) and device packaging was completed. As shown below:

##STR00023##

[0060] The device structure and manufacture method are basically completely the same; the difference lies in doping concentration and lies that organometallic complexes P0, P1, P2, P3 and P4 successively serve as dopants in the light-emitting layer. STD is an O∧N∧N∧O red emitting material.

##STR00024##

[0061] The devices STD, 1, 2, and 3 are successively prepared; the device structure and manufacture method are basically completely the same; the difference is that the platinum (II) complexes STD, TM-1, TM-3, and TM-5 successively serve as dopants in the light-emitting layer. The reference material STD is a typical red emitting material having an ONCN coordination structure.

[0062] Comparison results of the devices are shown in Table 1. With the performance of the device STD as standards, - represents holding the standard line; -- represents reduction by 5% above relative to the standard performance; + represents promotion by 5% relative to the standard performance; ++ represents promotion by 10% relative to the standard performance.

TABLE-US-00001 Device Device Device 1 2 3 Maximum external quantum efficiency − + ++ External quantum efficiency below + + ++ 100 nit Turn-on voltage − − − Current efficiency below 100 nit + + ++

[0063] Relative to the STD-based reference device, the TM-1-based device 1 basically has the same maximum external quantum efficiency and turn-on voltage, improved external quantum efficiency below 100 nit and current efficiency by 5% around; from the aspect of molecular structure, TM-1 and STD have a consistent plane structure, but TM-1 has a larger conjugated structure such that the device performance is improved to some extent relative to that of the STD. Relative to the reference device, the TM-3-based device 2 basically has the same turn-on voltage, and has improved maximum external quantum efficiency, external quantum efficiency below 100 nit and current efficiency by 5% around. From the aspect of molecular structure, 2 tert-butyl are brought in the TM-3 molecular structure to reduce the intermolecular aggregation and stacking to some extent, thus being beneficial to the performance improvement of device. Relative to the reference device, the TM-5-based device 3 basically has the same turn-on voltage, and has improved maximum external quantum efficiency, external quantum efficiency below 100 nit and current efficiency by 10% around. From the aspect of molecular structure, 4 tert-butyl are brought in the TM-3 molecular structure to greatly enhance the tridimensional property of molecules, greatly reduce the intermolecular interaction, and meanwhile to keep the rigid structure and large conjugate properties of the molecular skeleton. Therefore, the device has maximum efficiency promotion and optimal performance.

[0064] To sum up, relative to the reference device, the organic light-emitting device prepared by the present invention has better improvement in performance, obviously enhanced external quantum efficiency or current efficiency; and the related novel O∧C∧N∧N tetradentate platinum (II) complex metal organic material has greater application values. The tetradentate platinum (II) complex involved in the present invention is based on a carbazole framework, and has a large π-conjugated rigid planar structure, which can greatly reduce non-radiative energy dissipation such as intramolecular rotation and vibration, and is conducive to improving the luminous efficiency and performance of the platinum (II) complex. The O∧C∧N∧N tetradentate platinum (II) complex metal organic material prepared by the present invention has great application values in organic light-emitting diodes, and is used as a phosphorescent doping material to produce a red light OLED device with high luminous efficiency.