JP7613779B2 - Neutral iridium complexes coordinated with biphenyl derivatives, and methods for producing and using same - Google Patents

Description

The present invention belongs to the technical field of new materials, and in particular to neutral iridium complexes coordinated with biphenyl derivatives, as well as their preparation and use, particularly in organic light-emitting diodes.

Organic light-emitting diodes (OLEDs) are expected to be applied in photovoltaic devices (e.g., flat panel displays and lighting) due to the versatility of synthesis of organic semiconductor materials, low manufacturing costs, and excellent optical and electrical properties. In order to improve the luminous efficiency of organic light-emitting diodes, various luminescent material systems based on fluorescence and phosphorescence have been developed. Organic light-emitting diodes using fluorescent materials are characterized by high reliability, but the internal electroluminescence quantum efficiency under electric field excitation is limited to 25% because the ratio of the probability that excitons generate a singlet excited state and a triplet excited state is 1:3.

In 1999, Professor Thomson of the University of Southern California and Professor Forrest of Princeton University succeeded in creating a green electroluminescence device by doping N,N-dicarbazole biphenyl (CBP) with tris(2-phenylpyridine)iridium Ir(ppy) ₃ , which attracted attention to complex phosphorescent materials. The introduction of heavy metals enhances the molecular spin-orbit coupling, shortens the phosphorescence lifetime, strengthens the molecular intersystem crossing, and allows phosphorescence to be emitted smoothly. At present, the internal quantum efficiency of phosphorescent OLEDs has reached about 100%.

Regardless, most neutral phosphorescent iridium complex materials are composed of three monoanionic bidentate ligands (e.g., Ir(ppy) ₃ structure type, ppy is a monoanionic ligand), but there are few neutral phosphorescent iridium complexes composed of three charged ligands (neutral ligand, monoanionic ligand, and dianionic ligand), and especially, iridium complexes composed of biphenyl-containing dianionic ligands are difficult to synthesize, so few have been developed. Biphenyl has two carbon atoms in strong electric field coordination, which can increase the stability of the complex to a certain extent and can also increase the spin-orbit coupling effect (SOC) of the complex. However, in order to further improve the stability and optical properties of such complexes, it is necessary to perform a certain functional modification of the biphenyl ligand to form a biphenyl derivative ligand. Specifically, various functional groups having electronic effects (electron withdrawal, electron donation) and rigidity can be introduced into the active site of biphenyl. However, it is a big challenge to perform an effective functional modification of the biphenyl ligand.

The development of iridium complex materials containing biphenyl derivative ligands is urgently needed to further improve the properties of such iridium complex materials and to expand the range of material choices.

In response to the above-mentioned shortcomings of the prior art, the objective of the present invention is to provide an iridium complex containing a biphenyl derivative ligand. Specifically, first, an iridium complex intermediate with biphenyl coordinated thereto is prepared, and then, at low temperatures, the two active sites of biphenyl are selectively monobrominated and dibrominated, respectively. Then, a series of functional groups with various electronic effects (electron-withdrawing, electron-donating) and rigidity (carbazole, diphenylamine, acridine, 1,3-diphenylbenzene, 4,6-diphenyl-1,3,5-triazine, 4-benzenesulfonic acid benzene or phenoxy) are introduced to prepare a series of neutral iridium complex materials with novel biphenyl derivative coordinated thereto. The biphenyl derivative ligand contained in such a complex not only has two coordinated carbon atoms with a strong electric field effect, but also has various electronic effects (electron-withdrawing, electron-donating) and rigidity functional groups introduced therein, so that the stability, luminescence properties and performance of the corresponding device can be effectively improved.

（式中、Ｒ_１は、臭素、カルバゾール、ジフェニルアミン、アクリジン、３,５－ジフェニルベンゼン、４,６－ジフェニル－１,３,５－トリアジン、４－ベンゼンスルホン酸ベンゼン、又はフェノキシから選択される１種又は複数種である。）
前記中性イリジウム錯体は、下記錯体Ｉｒ１～Ｉｒ１６から選択される。

The present invention provides a neutral iridium complex having a biphenyl derivative coordinated thereto, the neutral iridium complex being represented by the general formula (I) or (II).

(In the formula, R ₁ is one or more selected from bromine, carbazole, diphenylamine, acridine, 3,5-diphenylbenzene, 4,6-diphenyl-1,3,5-triazine, 4-benzenesulfonate benzene, and phenoxy.)
The neutral iridium complex is selected from the following complexes Ir1 to Ir16.

An embodiment of the present invention is a method for producing a neutral iridium complex coordinated with the biphenyl derivative, comprising the steps of:
First, 1,5-cyclooctadiene iridium chloride dimer and biphenylene are used as raw materials, and under anhydrous and oxygen-free conditions, biphenyl, which is a dianionic ligand, is coordinated with metallic iridium by an oxidative addition reaction. Finally, a first-stage precursor 1-a is formed. Then, the chlorine atom is removed by the action of silver trifluoromethanesulfonate, and reacted with bipyridine, which is a neutral ligand with high coordination ability and rigidity, under mild conditions to obtain a precursor 1-b of a second-stage complex. Then, 2-phenylpyridine, which is a monoanionic ligand with higher coordination ability, is added in a high-temperature environment to replace the cyclooctadiene ligand with weak coordination ability, thereby forming a neutral iridium complex 1-c composed of three types of charged ligands.
Then, the biphenyl-coordinated iridium complex intermediate 1-c produced in step 1) is subjected to a bromination reaction, specifically, two active sites of biphenyl are selectively dibrominated and monobrominated, respectively, using N-bromosuccinimide (NBS) at a low temperature (ice bath), and finally, a dibrominated product Ir2 and a monobrominated product Ir1 are obtained, respectively, in step 2), in which the reaction temperature and the dropping speed of the NBS solution are controlled to reduce the production of by-products, thereby reducing the bromination of the active sites of the benzene ring in the monoanionic ligand 2-phenylpyridine;
Finally, the dibrominated product (Ir1) or monobrominated product (Ir2) prepared in step 2) can be directly subjected to a Buchwald-Hartwig coupling reaction with carbazole, diphenylamine, acridine, etc. to synthesize the corresponding iridium complexes (Ir3 to Ir8) coordinated with biphenyl derivatives, or can be subjected to a Suzuki coupling reaction with 3,5-diphenylphenylboronic acid to synthesize the corresponding iridium complexes (Ir9 to Ir10) coordinated with biphenyl derivatives, or can be subjected to a phenanthrene-coordinated iridium complex with potassium tert-butoxide. and step 3) forming diboronic acid ester-containing iridium complex intermediates 1-d and 1-e with bis(pinacolato)diboron, respectively, and then subjecting them to a Suzuki coupling reaction with 2-chloro-4,6-diphenyl-1,3,5-triazine or 1-bromo-4-(benzenesulfonyl)benzene, respectively, to synthesize a corresponding biphenyl derivative-coordinated iridium complex (Ir11 to Ir14).

Aspects of the present invention further include the use of the neutral iridium complex coordinated with the biphenyl derivative in the manufacture of an organic electronic device.

The organic electronic device is one or more of an organic light-emitting diode, an organic solar cell, an organic light-emitting cell, an organic field-effect transistor, an organic laser, an organic spintronic device, an organic sensor, and an organic plasmon emission diode.

The mass concentration of the neutral iridium complex coordinated with the biphenyl derivative in the matrix is 3 to 10 wt %.

The present invention further includes an organic electronic device comprising a neutral iridium complex coordinated with the biphenyl derivative.

The mass concentration of the neutral iridium complex coordinated with the biphenyl derivative is 3 to 10 wt %.

Aspects of the present invention further include the use of a neutral iridium complex coordinated with the biphenyl derivative in the manufacture of an organic electronic device.

The organic electronic devices are organic light emitting diodes (OLEDs), organic solar cells (OPVs), organic light emitting cells (OLEECs), organic field effect transistors (OFETs), organic optical field effect transistors, organic lasers, organic spintronic devices, organic sensors, and organic plasmon emitting diodes.

Beneficial Effects Compared with the prior art, the present invention has the following advantages. The biphenyl derivative ligand contained in the novel iridium complex prepared by the present invention not only has two coordinated carbon atoms with strong electric field effect, but also introduces functional groups with various electronic effects (electron-withdrawing, electron-donating) and rigidity, so that the stability, luminescent properties and performance of the corresponding device can be effectively improved. The present invention also relates to an organic electronic device, particularly an organic light-emitting diode, comprising the neutral metal iridium complex coordinated with the biphenyl derivative according to the present invention, and its use in display and lighting technology. By optimizing the device structure and changing the concentration of the neutral metal iridium complex coordinated with the biphenyl derivative in the matrix, the best device performance can be obtained, which makes it easy to realize OLED devices with high efficiency, high brightness and high stability, and provides an excellent material that can be used for full-color display and lighting applications.

1 is an X-ray single crystal structure of a neutral iridium complex Ir1 coordinated with a biphenyl derivative. 1 is an X-ray single crystal structure of a neutral iridium complex Ir2 coordinated with a biphenyl derivative. 1 is an X-ray single crystal structure of a neutral iridium complex Ir3 coordinated with a biphenyl derivative.

中間体１－ａの合成
乾燥した二つ口フラスコに１,５－シクロオクタジエンイリジウムクロリド二量体（０．４４ｇ、０．６６ｍｍｏｌ）、ビフェニレン（０．２ｇ、１．３１ｍｍｏｌ）を入れて、真空吸引して窒素を充填することを３回繰り返し、その後、乾燥ジクロロメタン５ｍＬを加え、９０^ｏＣで２時間撹拌して反応させ、室温に冷却し、吸引ろ過し、ろ過ケーキをジクロロメタンで洗浄し、黄色固体０．５７ｇを得て、収率は８５％であった。
中間体１－ｂの合成
乾燥シュレンク管に１－ａ（０．１０ｇ、０．１ｍｍｏｌ）、ビピリジン（０．０３ｇ、０．２ｍｍｏｌ）、トリフルオロメタンスルホン酸銀（０．０６ｇ、０．２２ｍｍｏｌ）を入れて、真空吸引して窒素を充填することを３回繰り返し、その後、窒素気流下で乾燥ジクロロメタン２５ｍＬを加え、室温で２時間撹拌し、吸引ろ過し、ろ液を１ｍＬまで濃縮させ、その後、大量の石油エーテルを加えて固体を析出させ、吸引ろ過し、乾燥し、黄色固体０．５６ｇを得て、収率は７５％であった。
中間体１－ｃの合成
乾燥した二つ口フラスコに１－ｂ（０．０８ｇ、０．１ｍｍｏｌ）、２－フェニルピリジン（０．０２ｇ、０．１２ｍｍｏｌ）を入れて、真空吸引して窒素を充填することを３回繰り返し、その後、窒素気流下でエタノール１０ｍＬを加え、９５^ｏＣで撹拌して２４時間還流反応し、室温に冷却し、有機相を濃縮し、酢酸エチル：石油エーテル＝１：３をカラムに通し、黄色固体０．０３ｇを得て、収率は４０％であった。
ビフェニル誘導体が配位した中性イリジウム錯体Ｉｒ１の合成
乾燥一つ口フラスコに１－ｃ（０．０３ｇ、０．０５ｍｍｏｌ）を入れて、ジクロロメタン１５ｍｌを加えて、完全に溶解させるまで撹拌し、その後、氷浴（０^ｏＣ）でＮ－ブロモスクシンイミドＮＢＳ（０．０２ｇ、０．１１ｍｍｏｌ）を含むジクロロメタン溶液１０ｍＬを反応フラスコにゆっくりと１滴ずつ滴下した。混合物を室温で１５時間撹拌した。反応終了後、水を加えて抽出し、有機相を濃縮し真空濃縮し、その後、シリカゲルカラムクロマトグラフィーによりジクロロメタン：石油エーテル＝２：１をカラムに通して目的の生成物を精製し、赤茶色固体０．０２ｇを得て、収率は６０％であった。
ビフェニル誘導体が配位した中性イリジウム錯体Ｉｒ１の単結晶は、溶媒としてのエタノールを用いてそのジクロロメタン溶液にゆっくりと拡散させたものであり、その構造が図１に示される。 Example 1: Synthesis of neutral iridium complex Ir1 coordinated with a biphenyl derivative. Synthesis route of neutral iridium complex Ir1 coordinated with a biphenyl derivative

Synthesis of Intermediate 1-a 1,5-cyclooctadiene iridium chloride dimer (0.44 g, 0.66 mmol) and biphenylene (0.2 g, 1.31 mmol) were placed in a dry two-neck flask, and the flask was evacuated and filled with nitrogen three times. Then, 5 mL of dry dichloromethane was added and the mixture was reacted at 90 ^° C. for 2 hours with stirring. The mixture was cooled to room temperature and filtered under suction. The filter cake was washed with dichloromethane to obtain 0.57 g of a yellow solid with a yield of 85%.
Synthesis of Intermediate 1-b 1-a (0.10 g, 0.1 mmol), bipyridine (0.03 g, 0.2 mmol), and silver trifluoromethanesulfonate (0.06 g, 0.22 mmol) were placed in a dry Schlenk flask, and the flask was evacuated and filled with nitrogen three times. Then, 25 mL of dry dichloromethane was added under a nitrogen stream, and the mixture was stirred at room temperature for 2 hours. The mixture was suction filtered and the filtrate was concentrated to 1 mL. A large amount of petroleum ether was then added to precipitate a solid, which was suction filtered and dried to obtain 0.56 g of a yellow solid. The yield was 75%.
Synthesis of intermediate 1-c 1-b (0.08 g, 0.1 mmol) and 2-phenylpyridine (0.02 g, 0.12 mmol) were placed in a dry two-neck flask, and the flask was evacuated and filled with nitrogen three times. Then, 10 mL of ethanol was added under a nitrogen stream, and the mixture was stirred at 95 ^° C. under reflux for 24 hours. The mixture was cooled to room temperature, and the organic phase was concentrated and passed through a column with ethyl acetate:petroleum ether=1:3 to obtain 0.03 g of a yellow solid with a yield of 40%.
Synthesis of neutral iridium complex Ir1 coordinated with biphenyl derivative 1-c (0.03 g, 0.05 mmol) was placed in a dry one-neck flask, 15 ml of dichloromethane was added, and the mixture was stirred until completely dissolved. Then, 10 mL of dichloromethane solution containing N-bromosuccinimide NBS (0.02 g, 0.11 mmol) was slowly added dropwise to the reaction flask in an ice bath (0 ^o C). The mixture was stirred at room temperature for 15 hours. After the reaction was completed, water was added for extraction, and the organic phase was concentrated and concentrated in vacuum. The desired product was then purified by silica gel column chromatography using dichloromethane:petroleum ether = 2:1 through the column to obtain 0.02 g of a red-brown solid, with a yield of 60%.
A single crystal of the neutral iridium complex Ir1 coordinated with a biphenyl derivative was slowly dispersed in its dichloromethane solution using ethanol as the solvent, and its structure is shown in FIG.

乾燥した一つ口フラスコに１－ｃ（０．０３ｇ、０．０５ｍｍｏｌ）を入れて、ジクロロメタン１５ｍｌを加え、完全に溶解させるまで撹拌し、その後、氷浴（０^ｏＣ）でＮ－ブロモスクシンイミドＮＢＳ（０．０１ｇ、０．５５ｍｍｏｌ）を含むジクロロメタン溶液１０ｍＬを反応フラスコにゆっくりと１滴ずつ滴下した。混合物を室温で１５時間撹拌した。反応終了後、水を加えて抽出し、有機相を濃縮し真空濃縮し、その後、シリカゲルカラムクロマトグラフィーによりジクロロメタン：石油エーテル＝２：１をカラムに通して目的の生成物を精製し、赤茶色固体０．０２ｇを得て、収率は６５％であった。
ビフェニル誘導体が配位した中性イリジウム錯体Ｉｒ２の単結晶も、溶媒としてのエタノールを用いてそのジクロロメタン溶液にゆっくりと拡散させたものであり、その構造が図２に示される。 Example 2: Synthesis of neutral iridium complex Ir2 coordinated with a biphenyl derivative. Synthesis route of neutral iridium complex Ir2 coordinated with a biphenyl derivative

1-c (0.03 g, 0.05 mmol) was placed in a dry one-neck flask, 15 ml of dichloromethane was added, and the mixture was stirred until completely dissolved. Then, 10 mL of a dichloromethane solution containing N-bromosuccinimide NBS (0.01 g, 0.55 mmol) was slowly added dropwise to the reaction flask in an ice bath (0 ^o C). The mixture was stirred at room temperature for 15 hours. After the reaction was completed, water was added for extraction, and the organic phase was concentrated and concentrated in vacuum. The product was then purified by silica gel column chromatography using dichloromethane:petroleum ether = 2:1 through the column to obtain 0.02 g of a red-brown solid, with a yield of 65%.
A single crystal of the neutral iridium complex Ir2 coordinated with a biphenyl derivative was also slowly dispersed in its dichloromethane solution using ethanol as the solvent, and its structure is shown in FIG.

乾燥した二つ口フラスコにＩｒ１（０．０８ｇ、０．１ｍｍｏｌ）、カルバゾール（０．０５ｇ、０．３ｍｍｏｌ）、リン酸カリウム（０．６４ｇ、３ｍｍｏｌ）、トリ－ｔ－ブチルホスフィン（０．３ｍＬ、０．１ｇ／ｍＬ）、Ｐｄ（ＯＡｃ）_２（０．０１ｇ、０．０４ｍｍｏｌ）を入れて、真空吸引して窒素を充填することを３回繰り返し、その後、ｐ－キシレン２０ｍＬを加え、２４時間撹拌して還流反応し、室温に冷却し、水を加えて、ジクロロメタンで抽出し、水洗して濃縮し、酢酸エチル：石油エーテル＝１：５をカラムに通して精製を行い、茶色固体０．０４ｇを得て、収率は４０％であった。
ビフェニル誘導体が配位した中性イリジウム錯体Ｉｒ３の単結晶も、溶媒としてのエタノールを用いてそのジクロロメタン溶液にゆっくりと拡散させたものであり、その構造が図３に示される。 Example 3: Synthesis of neutral iridium complex Ir3 coordinated with biphenyl derivative Synthetic route for neutral iridium complex Ir3 coordinated with biphenyl derivative

A dried two-neck flask was charged with Ir1 (0.08 g, 0.1 mmol), carbazole (0.05 g, 0.3 mmol), potassium phosphate (0.64 g, 3 mmol), tri-t-butylphosphine (0.3 mL, 0.1 g/mL), and Pd(OAc) ₂ (0.01 g, 0.04 mmol), and the flask was evacuated and filled with nitrogen three times. Then, 20 mL of p-xylene was added, and the mixture was stirred and refluxed for 24 hours. The mixture was cooled to room temperature, water was added, and the mixture was extracted with dichloromethane, washed with water, concentrated, and purified by passing the mixture through a column with ethyl acetate:petroleum ether=1:5 to obtain 0.04 g of a brown solid, with a yield of 40%.
A single crystal of the neutral iridium complex Ir3 coordinated with a biphenyl derivative was also slowly dispersed in its dichloromethane solution using ethanol as the solvent, and its structure is shown in FIG.

乾燥した二つ口フラスコにＩｒ２（０．０７ｇ、０．１ｍｍｏｌ）、カルバゾール（０．０３ｇ、０．１５ｍｍｏｌ）、リン酸カリウム（０．３２ｇ、１．５ｍｍｏｌ）、トリ－ｔ－ブチルホスフィン（０．３ｍＬ、０．１ｇ／ｍＬ）、Ｐｄ（ＯＡｃ）_２（０．０１ｇ、０．０４ｍｍｏｌ）を入れて、真空吸引して窒素を充填することを３回繰り返し、その後、ｐ－キシレン２０ｍＬを加え、２４時間撹拌して還流反応し、室温に冷却し、水を加えて、ジクロロメタンで抽出し、水洗して濃縮し、酢酸エチル：石油エーテル＝１：５をカラムに通して精製を行い、茶色固体０．０４ｇを得て、収率は４５％であった。 Example 4 Synthesis of neutral iridium complex Ir4 coordinated with a biphenyl derivative Synthesis route of neutral iridium complex Ir4 coordinated with a biphenyl derivative

A dried two-neck flask was charged with Ir2 (0.07 g, 0.1 mmol), carbazole (0.03 g, 0.15 mmol), potassium phosphate (0.32 g, 1.5 mmol), tri-t-butylphosphine (0.3 mL, 0.1 g/mL), and Pd(OAc) ₂ (0.01 g, 0.04 mmol), and the flask was evacuated and filled with nitrogen three times. Then, 20 mL of p-xylene was added, and the mixture was refluxed for 24 hours while stirring. The mixture was cooled to room temperature, water was added, and the mixture was extracted with dichloromethane, washed with water, concentrated, and purified by passing the mixture through a column with ethyl acetate:petroleum ether = 1:5 to obtain 0.04 g of a brown solid, with a yield of 45%.

乾燥した二つ口フラスコにＩｒ１（０．０８ｇ、０．１ｍｍｏｌ）、ジフェニルアミン（０．０５ｇ、０．３ｍｍｏｌ）、リン酸カリウム（０．６４ｇ、３ｍｍｏｌ）、トリ－ｔ－ブチルホスフィン（０．３ｍＬ、０．１ｇ／ｍＬ）、Ｐｄ（ＯＡｃ）_２（０．０１ｇ、０．０４ｍｍｏｌ）を入れて、真空吸引して窒素を充填することを３回繰り返し、その後、ｐ－キシレン２０ｍＬを加え、２４時間撹拌して還流反応し、室温に冷却し、水を加えて、ジクロロメタンで抽出し、水洗して濃縮し、酢酸エチル：石油エーテル＝１：５をカラムに通して精製を行い、茶色固体０．０３ｇを得て、収率は３５％であった。 Example 5: Synthesis of neutral iridium complex Ir5 coordinated with biphenyl derivative. Synthesis route of neutral iridium complex Ir5 coordinated with biphenyl derivative

A dried two-neck flask was charged with Ir1 (0.08 g, 0.1 mmol), diphenylamine (0.05 g, 0.3 mmol), potassium phosphate (0.64 g, 3 mmol), tri-t-butylphosphine (0.3 mL, 0.1 g/mL), and Pd(OAc) ₂ (0.01 g, 0.04 mmol), and the flask was evacuated and filled with nitrogen three times. Then, 20 mL of p-xylene was added, and the mixture was stirred and refluxed for 24 hours. The mixture was cooled to room temperature, water was added, and the mixture was extracted with dichloromethane, washed with water, concentrated, and purified by passing the mixture through a column with ethyl acetate:petroleum ether=1:5 to obtain 0.03 g of a brown solid, with a yield of 35%.

乾燥した二つ口フラスコにＩｒ２（０．０７ｇ、０．１ｍｍｏｌ）、ジフェニルアミン（０．０３ｇ、０．１５ｍｍｏｌ）、リン酸カリウム（０．３２ｇ、１．５ｍｍｏｌ）、トリ－ｔ－ブチルホスフィン（０．３ｍＬ、０．１ｇ／ｍＬ）、Ｐｄ（ＯＡｃ）_２（０．０１ｇ、０．０４ｍｍｏｌ）を入れて、真空吸引して窒素を充填することを３回繰り返し、その後、ｐ－キシレン２０ｍＬを加え、２４時間撹拌して還流反応し、室温に冷却し、水を加えて、ジクロロメタンで抽出し、水洗して濃縮し、酢酸エチル：石油エーテル＝１：５をカラムに通して精製を行い、茶色固体０．０３ｇを得て、収率は４０％であった。 Example 6 Synthesis of neutral iridium complex Ir6 coordinated with a biphenyl derivative

A dried two-neck flask was charged with Ir2 (0.07 g, 0.1 mmol), diphenylamine (0.03 g, 0.15 mmol), potassium phosphate (0.32 g, 1.5 mmol), tri-t-butylphosphine (0.3 mL, 0.1 g/mL), and Pd(OAc) ₂ (0.01 g, 0.04 mmol), and the flask was evacuated and filled with nitrogen three times. Then, 20 mL of p-xylene was added, and the mixture was stirred and refluxed for 24 hours. The mixture was cooled to room temperature, water was added, and the mixture was extracted with dichloromethane, washed with water, concentrated, and purified by passing the mixture through a column with ethyl acetate:petroleum ether = 1:5 to obtain 0.03 g of a brown solid, with a yield of 40%.

乾燥した二つ口フラスコにＩｒ１（０．０８ｇ、０．１ｍｍｏｌ）、アクリジン（０．０６ｇ、０．３ｍｍｏｌ）、リン酸カリウム（０．６４ｇ、３ｍｍｏｌ）、トリ－ｔ－ブチルホスフィン（０．３ｍＬ、０．１ｇ／ｍＬ）、Ｐｄ（ＯＡｃ）_２（０．０１ｇ、０．０４ｍｍｏｌ）を入れて、真空吸引して窒素を充填することを３回繰り返し、その後、ｐ－キシレン２０ｍＬを加え、２４時間撹拌して還流反応し、室温に冷却し、水を加えて、ジクロロメタンで抽出し、水洗して濃縮し、酢酸エチル：石油エーテル＝１：５をカラムに通して精製を行い、茶色固体０．０４ｇを得て、収率は４２％であった。 Example 7 Synthesis of neutral iridium complex Ir7 coordinated with biphenyl derivative Synthetic route for neutral iridium complex Ir7 coordinated with biphenyl derivative

A dried two-neck flask was charged with Ir1 (0.08 g, 0.1 mmol), acridine (0.06 g, 0.3 mmol), potassium phosphate (0.64 g, 3 mmol), tri-t-butylphosphine (0.3 mL, 0.1 g/mL), and Pd(OAc) ₂ (0.01 g, 0.04 mmol), and the flask was evacuated and filled with nitrogen three times. Then, 20 mL of p-xylene was added, and the mixture was stirred and refluxed for 24 hours. The mixture was cooled to room temperature, water was added, and the mixture was extracted with dichloromethane, washed with water, concentrated, and purified by passing the mixture through a column with ethyl acetate:petroleum ether=1:5 to obtain 0.04 g of a brown solid, with a yield of 42%.

乾燥した二つ口フラスコにＩｒ２（０．０７ｇ、０．１ｍｍｏｌ）、アクリジン（０．０３ｇ、０．１５ｍｍｏｌ）、リン酸カリウム（０．３２ｇ、１．５ｍｍｏｌ）、トリ－ｔ－ブチルホスフィン（０．３ｍＬ、０．１ｇ／ｍＬ）、Ｐｄ（ＯＡｃ）_２（０．０１ｇ、０．０４ｍｍｏｌ）を入れて、真空吸引して窒素を充填することを３回繰り返し、その後、ｐ－キシレン２０ｍＬを加え、２４時間撹拌して還流反応し、室温に冷却し、水を加えて、ジクロロメタンで抽出し、水洗して濃縮し、酢酸エチル：石油エーテル＝１：５をカラムに通して精製を行い、茶色固体０．０４ｇを得て、収率は４５％であった。 Example 8: Synthesis of neutral iridium complex Ir8 coordinated with biphenyl derivatives. Synthesis route of neutral iridium complex Ir8 coordinated with biphenyl derivatives.

A dried two-neck flask was charged with Ir2 (0.07 g, 0.1 mmol), acridine (0.03 g, 0.15 mmol), potassium phosphate (0.32 g, 1.5 mmol), tri-t-butylphosphine (0.3 mL, 0.1 g/mL), and Pd(OAc) ₂ (0.01 g, 0.04 mmol), and the flask was evacuated and filled with nitrogen three times. Then, 20 mL of p-xylene was added, and the mixture was stirred and refluxed for 24 hours. The mixture was cooled to room temperature, water was added, and the mixture was extracted with dichloromethane, washed with water, concentrated, and purified by passing the mixture through a column with ethyl acetate:petroleum ether = 1:5 to obtain 0.04 g of a brown solid, with a yield of 45%.

乾燥した二つ口フラスコにＩｒ１（０．０８ｇ、０．１ｍｍｏｌ）、３,５－ジフェニルフェニルボロン酸（０．０８ｇ、０．３ｍｍｏｌ）、及びテトラキス（トリフェニルホスフィン）パラジウム（０．０２ｇ、０．０２ｍｍｏｌ）を入れて、真空吸引して窒素を充填することを３回繰り返し、その後、窒素気流下でＫ_２ＣＯ_３溶液（２Ｍ、１０ｍＬ）、１,４－ジオキサン（２０ｍＬ）を加え、２４時間撹拌して還流反応し、水を加えて、ジクロロメタンで抽出し、水洗して濃縮し、酢酸エチル：石油エーテル＝１：５をカラムに通して精製を行い、茶色固体０．０７ｇを得て、収率は６０％であった。 Example 9: Synthesis of neutral iridium complex Ir9 coordinated with a biphenyl derivative. Synthetic route for neutral iridium complex Ir9 coordinated with a biphenyl derivative

Ir1 (0.08 g, 0.1 mmol), 3,5-diphenylphenylboronic acid (0.08 g, 0.3 mmol), and tetrakis(triphenylphosphine)palladium (0.02 g, 0.02 mmol) were placed in a dried two-neck flask, and the mixture was evacuated and filled with nitrogen three times. Then, under a nitrogen stream, K ₂ CO ₃ solution (2 M, 10 mL) and 1,4-dioxane (20 mL) were added, and the mixture was stirred and refluxed for 24 hours. Water was added, and the mixture was extracted with dichloromethane, washed with water, concentrated, and purified by passing it through a column with ethyl acetate:petroleum ether = 1:5 to obtain 0.07 g of a brown solid, with a yield of 60%.

乾燥した二つ口フラスコにＩｒ２（０．０７ｇ、０．１ｍｍｏｌ）、３,５－ジフェニルフェニルボロン酸（０．０４ｇ、０．１５ｍｍｏｌ）、及びテトラキス（トリフェニルホスフィン）パラジウム（０．０１ｇ、０．０１ｍｍｏｌ）を入れて、真空吸引して窒素を充填することを３回繰り返し、その後、窒素気流下でＫ_２ＣＯ_３溶液（２Ｍ、１０ｍＬ）、１,４－ジオキサン（２０ｍＬ）を加え、２４時間撹拌して還流反応し、水を加えて、ジクロロメタンで抽出し、水洗して濃縮し、酢酸エチル：石油エーテル＝１：５をカラムに通して精製を行い、茶色固体０．０６ｇを得て、収率は６５％であった。 Example 10: Synthesis of neutral iridium complex Ir10 coordinated with a biphenyl derivative. Synthesis route of neutral iridium complex Ir10 coordinated with a biphenyl derivative.

Ir2 (0.07 g, 0.1 mmol), 3,5-diphenylphenylboronic acid (0.04 g, 0.15 mmol), and tetrakis(triphenylphosphine)palladium (0.01 g, 0.01 mmol) were placed in a dried two-neck flask, and _the mixture was evacuated and filled with nitrogen three times. Then, under a nitrogen stream, _K2CO3 solution (2 M, 10 mL) and 1,4-dioxane (20 mL) were added, and the mixture was stirred and refluxed for 24 hours. Water was added, and the mixture was extracted with dichloromethane, washed with water, concentrated, and purified by passing it through a column with ethyl acetate:petroleum ether = 1:5 to obtain 0.06 g of a brown solid, with a yield of 65%.

中間体１－ｄの合成
乾燥した二つ口フラスコにＩｒ１（０．４０ｇ、０．５ｍｍｏｌ）、ビス（ピナコラト）ジボロン（０．３８ｇ、１．５ ｍｍｏｌ）、Ｐｄ（ｄｐｐｆ）_２Ｃｌ_２（０．０２ｇ、０．０３ｍｍｏｌ）、ＫＯＡｃ（１ｇ、１０ｍｍｏｌ）を入れて、真空吸引して窒素を充填することを３回繰り返し、ジオキサン３０ｍＬを加え、その後、遮光の条件で２４時間加熱還流し、室温に冷却し、水を加えて、酢酸エチルで抽出し、濃縮し、その後、ジクロロメタン：石油エーテル＝１：３をカラムに通して精製を行い、茶色固体０．２９ｇを得て、収率は６５％であった。
ビフェニル誘導体が配位した中性イリジウム錯体Ｉｒ１１の合成
乾燥した二つ口フラスコに１－ｄ（０．０９ｇ、０．１ｍｍｏｌ）、２－クロロ－４,６－ジフェニル－１,３,５－トリアジン（０．０５ｇ、０．２ｍｍｏｌ）、及びテトラキス（トリフェニルホスフィン）パラジウム（０．０２ｇ、０．０２ｍｍｏｌ）を入れて、真空吸引して窒素を充填することを３回繰り返し、その後、窒素気流下でＫ_２ＣＯ_３溶液（２Ｍ、１０ｍＬ）、１,４－ジオキサン（２０ｍＬ）を加え、４８時間撹拌して還流反応し、水を加えて、ジクロロメタンで抽出し、水洗して濃縮し、酢酸エチル：石油エーテル＝１：３をカラムに通して精製を行い、茶色固体０．０７ｇを得て、収率は６５％であった。 Synthesis Example 11 Synthesis of neutral iridium complex Ir11 coordinated with a biphenyl derivative Synthesis route of neutral iridium complex Ir11 coordinated with a biphenyl derivative

Synthesis of intermediate 1-d Ir1 (0.40 g, 0.5 mmol), bis(pinacolato)diboron (0.38 g, 1.5 mmol), Pd(dppf) ₂ Cl ₂ (0.02 g, 0.03 mmol), and KOAc (1 g, 10 mmol) were placed in a dry two-neck flask, and the flask was evacuated and filled with nitrogen three times. 30 mL of dioxane was added, and the flask was heated under reflux for 24 hours in the dark. The flask was cooled to room temperature, and water was added. The mixture was extracted with ethyl acetate and concentrated. The mixture was then purified by passing the mixture through a column with dichloromethane:petroleum ether=1:3 to obtain 0.29 g of a brown solid, with a yield of 65%.
Synthesis of neutral iridium complex Ir11 coordinated with biphenyl derivative 1-d (0.09 g, 0.1 mmol), 2-chloro-4,6-diphenyl-1,3,5-triazine (0.05 g, 0.2 mmol), and tetrakis(triphenylphosphine)palladium (0.02 g, 0.02 mmol) were placed in a dry two-neck flask, and the flask was evacuated and filled with nitrogen three times. Then, under a nitrogen stream, K ₂ CO ₃ solution (2 M, 10 mL) and 1,4-dioxane (20 mL) were added, and the mixture was stirred and refluxed for 48 hours. Water was added, and the mixture was extracted with dichloromethane, washed with water, concentrated, and purified by passing it through a column with ethyl acetate:petroleum ether = 1:3 to obtain 0.07 g of a brown solid, with a yield of 65%.

中間体１－ｅの合成
乾燥した二つ口フラスコにＩｒ２（０．７３ｇ、１ｍｍｏｌ）、ビス（ピナコラト）ジボロン（０．３８ｇ、１．５ ｍｍｏｌ）、Ｐｄ（ｄｐｐｆ）_２Ｃｌ_２（０．０２ｇ、０．０３ｍｍｏｌ）、ＫＯＡｃ（１ｇ、１０ｍｍｏｌ）を入れて、真空吸引して窒素を充填することを３回繰り返し、ジオキサン３０ｍＬを加え、その後、遮光の条件で２４時間加熱還流し、室温に冷却し、水を加えて、酢酸エチルで抽出し、濃縮し、その後、ジクロロメタン：石油エーテル＝１：３をカラムに通して精製を行い、茶色固体０．５５ｇを得て、収率は７０％であった。
ビフェニル誘導体が配位した中性イリジウム錯体Ｉｒ１２の合成
乾燥した二つ口フラスコに１－ｅ（０．１６ｇ、０．２ｍｍｏｌ）、２－クロロ－４,６－ジフェニル－１,３,５－トリアジン（０．０５ｇ、０．２ｍｍｏｌ）、及びテトラキス（トリフェニルホスフィン）パラジウム（０．０２ｇ、０．０２ｍｍｏｌ）を入れて、真空吸引して窒素を充填することを３回繰り返し、その後、窒素気流下でＫ_２ＣＯ_３溶液（２Ｍ、１０ｍＬ）、１,４－ジオキサン（２０ｍＬ）を加え、４８時間撹拌して還流反応し、水を加えて、ジクロロメタンで抽出し、水洗して濃縮し、酢酸エチル：石油エーテル＝１：３をカラムに通して精製を行い、茶色固体０．１２ｇを得て、収率は６８％であった。 Example 12: Synthesis of neutral iridium complex Ir12 coordinated with a biphenyl derivative. Synthetic route for neutral iridium complex Ir12 coordinated with a biphenyl derivative

Synthesis of intermediate 1-e Ir2 (0.73 g, 1 mmol), bis(pinacolato)diboron (0.38 g, 1.5 mmol), Pd(dppf) ₂ Cl ₂ (0.02 g, 0.03 mmol), and KOAc (1 g, 10 mmol) were placed in a dry two-neck flask, and the flask was evacuated and filled with nitrogen three times. 30 mL of dioxane was added, and the flask was heated under reflux for 24 hours in the dark. The flask was cooled to room temperature, and water was added. The mixture was extracted with ethyl acetate and concentrated. The mixture was then purified by passing it through a column with dichloromethane:petroleum ether=1:3 to obtain 0.55 g of a brown solid, with a yield of 70%.
Synthesis of neutral iridium complex Ir12 coordinated with biphenyl derivative 1-e (0.16 g, 0.2 mmol), 2-chloro-4,6-diphenyl-1,3,5-triazine (0.05 g, 0.2 mmol), and tetrakis(triphenylphosphine)palladium (0.02 g, 0.02 mmol) were placed in a dry two-neck flask, and the flask was evacuated and filled with nitrogen three times. Then, under a nitrogen stream, K ₂ CO ₃ solution (2 M, 10 mL) and 1,4-dioxane (20 mL) were added, and the mixture was stirred and refluxed for 48 hours. Water was added, and the mixture was extracted with dichloromethane, washed with water, concentrated, and purified by passing it through a column with ethyl acetate:petroleum ether = 1:3 to obtain 0.12 g of a brown solid, with a yield of 68%.

乾燥した二つ口フラスコに１－ｄ（０．０９ｇ、０．１ｍｍｏｌ）、１－ブロモ－４－（ベンゼンスルホニル）ベンゼン（０．０６ｇ、０．２ｍｍｏｌ）、及びテトラキス（トリフェニルホスフィン）パラジウム（０．０２ｇ、０．０２ｍｍｏｌ）を入れて、真空吸引して窒素を充填することを３回繰り返し、その後、窒素気流下でＫ_２ＣＯ_３溶液（２Ｍ、１０ｍＬ）、１,４－ジオキサン（２０ｍＬ）を加え、２４時間撹拌して還流反応し、水を加えて、ジクロロメタンで抽出し、水洗して濃縮し、酢酸エチル：石油エーテル＝１：３をカラムに通して精製を行い、茶色固体０．０７ｇを得て、収率は６８％であった。 Example 13: Synthesis of neutral iridium complex Ir13 coordinated with a biphenyl derivative. Synthetic route for neutral iridium complex Ir13 coordinated with a biphenyl derivative

In a dried two-neck flask, 1-d (0.09 g, 0.1 mmol), 1-bromo-4-(benzenesulfonyl)benzene (0.06 g, 0.2 mmol), and tetrakis(triphenylphosphine)palladium (0.02 g, 0.02 mmol) were placed, and the mixture was evacuated and filled with nitrogen three times. Then, under a nitrogen stream, K ₂ CO ₃ solution (2 M, 10 mL) and 1,4-dioxane (20 mL) were added, and the mixture was stirred and refluxed for 24 hours. Water was added, and the mixture was extracted with dichloromethane, washed with water, concentrated, and purified by passing it through a column with ethyl acetate:petroleum ether = 1:3 to obtain 0.07 g of a brown solid, with a yield of 68%.

乾燥した二つ口フラスコに１－ｅ（０．１６ｇ、０．２ｍｍｏｌ）、１－ブロモ－４－（ベンゼンスルホニル）ベンゼン（０．０６ｇ、０．２ｍｍｏｌ）、及びテトラキス（トリフェニルホスフィン）パラジウム（０．０２ｇ、０．０２ｍｍｏｌ）を入れて、真空吸引して窒素を充填することを３回繰り返し、その後、窒素気流下でＫ_２ＣＯ_３溶液（２Ｍ、１０ｍＬ）、１,４－ジオキサン（２０ｍＬ）を加え、２４時間撹拌して還流反応し、水を加えて、ジクロロメタンで抽出し、水洗して濃縮し、酢酸エチル：石油エーテル＝１：３をカラムに通して精製を行い、茶色固体０．１３ｇを得て、収率は７５％であった。 Example 14: Synthesis of neutral iridium complex Ir14 coordinated with a biphenyl derivative

In a dried two-neck flask, 1-e (0.16 g, 0.2 mmol), 1-bromo-4-(benzenesulfonyl)benzene (0.06 g, 0.2 mmol), and tetrakis(triphenylphosphine)palladium (0.02 g, 0.02 mmol) were placed, and the mixture was evacuated and filled with nitrogen three times. Then, under a nitrogen stream, K ₂ CO ₃ solution (2 M, 10 mL) and 1,4-dioxane (20 mL) were added, and the mixture was stirred and refluxed for 24 hours. Water was added, and the mixture was extracted with dichloromethane, washed with water, concentrated, and purified by passing it through a column with ethyl acetate:petroleum ether = 1:3 to obtain 0.13 g of a brown solid, with a yield of 75%.

乾燥した二つ口フラスコにＩｒ１（０．０８ｇ、０．１ｍｍｏｌ）、フェノール（０．０３ｇ、０．３ｍｍｏｌ）、及びカリウムｔｅｒｔ－ブトキシド（０．０７ｇ、０．６ｍｍｏｌ）を入れて、真空吸引して窒素を充填することを３回繰り返し、その後、窒素気流下でジメチルスルホキシドＤＭＳＯ（２０ｍＬ）を加え、５０^ｏＣで１２時間撹拌して反応させ、水を加えて、酢酸エチルで複数回抽出し、水洗して濃縮し、酢酸エチル：石油エーテル＝１：４をカラムに通して精製を行い、茶色固体０．０５ｇを得て、収率は６０％であった。 Example 15: Synthesis of neutral iridium complex Ir15 coordinated with a biphenyl derivative. Synthetic route for neutral iridium complex Ir15 coordinated with a biphenyl derivative

Ir1 (0.08 g, 0.1 mmol), phenol (0.03 g, 0.3 mmol), and potassium tert-butoxide (0.07 g, 0.6 mmol) were placed in a dried two-neck flask, and the flask was evacuated and filled with nitrogen three times. Dimethyl sulfoxide (DMSO) (20 mL) was then added under a nitrogen stream, and the mixture was stirred at 50 ^° C. for 12 hours to react. Water was added, and the mixture was extracted multiple times with ethyl acetate, washed with water, concentrated, and purified by passing the mixture through a column with ethyl acetate:petroleum ether=1:4 to obtain 0.05 g of a brown solid, with a yield of 60%.

乾燥した二つ口フラスコにＩｒ２（０．１５ｇ、０．２ｍｍｏｌ）、フェノール（０．０３ｇ、０．３ｍｍｏｌ）、及びカリウムｔｅｒｔ－ブトキシド（０．０７ｇ、０．６ｍｍｏｌ）を入れて、真空吸引して窒素を充填することを３回繰り返し、その後、窒素気流下でジメチルスルホキシドＤＭＳＯ（２０ｍＬ）を加え、５０^ｏＣで１２時間撹拌して反応させ、水を加えて、酢酸エチルで複数回抽出し、水洗して濃縮し、酢酸エチル：石油エーテル＝１：５をカラムに通して精製を行い、茶色固体０．１０ｇを得て、収率は７０％であった。 Example 16: Synthesis of neutral iridium complex Ir16 coordinated with a biphenyl derivative. Synthetic route for neutral iridium complex Ir16 coordinated with a biphenyl derivative

Ir2 (0.15 g, 0.2 mmol), phenol (0.03 g, 0.3 mmol), and potassium tert-butoxide (0.07 g, 0.6 mmol) were placed in a dried two-neck flask, and the flask was evacuated and filled with nitrogen three times. Dimethyl sulfoxide (DMSO) (20 mL) was then added under a nitrogen stream, and the mixture was stirred at 50 ^° C. for 12 hours to react. Water was added, and the mixture was extracted multiple times with ethyl acetate, washed with water, concentrated, and purified by passing the mixture through a column with ethyl acetate:petroleum ether=1:5 to obtain 0.10 g of a brown solid, with a yield of 70%.

Example 17 Fabrication and Characterization of OLED Device The steps to fabricate an OLED device with ITO/PEDOT:PSS(40 nm)/EML(80 nm)/TPBi(30 nm)/LiF(1 nm)/Al(120 nm)/cathode are as follows.
(i) After ultrasonic treatment for 30 minutes using an aqueous solution of 5% Decon 90 cleaning solution, ultrasonic cleaning was performed multiple times with deionized water, followed by ultrasonic cleaning with isopropanol and drying with nitrogen spray. The ITO surface was cleaned by treatment with oxygen plasma for 5 minutes to improve the work function of the ITO electrode.
(ii) The PEDOT:PSS solution was spin-coated onto an oxygen plasma-treated ITO glass substrate to obtain a 40 nm thin film, which was then annealed in air at 150° C. for 20 minutes after spin-coating. PEDOT:PSS is an aqueous solution of a polymer consisting of two substances, PEDOT and PSS, where PEDOT is a polymer of 3,4-ethylenedioxythiophene monomer and PSS is polystyrene sulfonate.
(iii) First, PVK, PBD, and complexes (Ir1 to Ir16) were dissolved in toluene so that the mass ratio of the materials was 60-67:30:3-10, and the solution was spin-coated in a nitrogen glove box to obtain a 80 nm thin film, which was then annealed at 120° C. for 10 minutes. PVK is an abbreviation for polyethylenecarbazole, and PBD is an abbreviation for 2-(4-t-butylphenyl)-5-biphenyloxadiazole.
(iv) The spin-coated device was placed in a vacuum deposition chamber to deposit 30 nm TPBi, 1 nm LiF and 100 nm aluminum in that order to fabricate a light-emitting device. TPBi is the abbreviation for 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene. The current-voltage-luminance (JVL) characteristics of the OLED device were characterized by a characterization device and the important parameters such as efficiency and external quantum efficiency were recorded. The maximum external quantum efficiency (EQE) of the OLED was detected to be 12%.
Specifically, the following applies:

Further optimization, such as optimizing the device structure and optimizing the combination of hole transport material (HTM), electron transport material (ETM) and host material, can further improve the device performance, especially efficiency, driving voltage and extend the lifetime.

Claims (7)

The complexes are selected from the following complexes Ir3 to Ir6 and Ir9 to Ir16:
A neutral iridium complex having a biphenyl derivative coordinated thereto, characterized in that:

A method for producing a neutral iridium complex coordinated with the biphenyl derivative according to claim 1, comprising the steps of:
First, 1,5-cyclooctadiene iridium chloride dimer and biphenylene are used as raw materials, and under anhydrous and oxygen-free conditions, biphenyl, which is a dianionic ligand, is coordinated with metallic iridium by an oxidative addition reaction to form a first-stage precursor 1-a. Then, the chlorine atom is removed by the action of silver trifluoromethanesulfonate, and the first-stage precursor 1-a is reacted with bipyridine, which is a neutral ligand, under mild conditions to obtain a precursor of a second-stage complex 1-b. Then, 2-phenylpyridine, which is a monoanionic ligand, is added in a high-temperature environment to obtain a neutral iridium complex 1-c.
Then, the biphenyl-coordinated iridium complex intermediate 1-c prepared in step 1) is subjected to a directed bromination reaction, specifically, the two active sites of biphenyl are selectively dibrominated and monobrominated, respectively, using N-bromosuccinimide at low temperature, and finally, the dibrominated product Ir 1

and the monobrominated product Ir2

Step 2) to obtain
Finally, the dibrominated product Ir1 or the monobrominated product Ir2 prepared in step 2) is directly subjected to a Buchwald-Hartwig coupling reaction with carbazole or diphenylamine to synthesize the corresponding biphenyl derivative-coordinated iridium complexes Ir3 to Ir6, or is subjected to a Suzuki coupling reaction with 3,5-diphenylphenylboronic acid to synthesize the corresponding biphenyl derivative-coordinated iridium complexes Ir9 to Ir10, or is subjected to an etherification reaction with phenol under the action of potassium tert-butoxide to synthesize the corresponding biphenyl derivative-coordinated iridium complexes Ir15 to Ir16, or is reacted with bis(pinacolato)diboron to synthesize a diboronic acid ester-containing iridium complex intermediate 1-d.

and boronate ester-containing iridium complex intermediate 1-e

and then subjecting the resulting iridium complexes Ir11 to Ir14 coordinated with the corresponding biphenyl derivatives to a Suzuki coupling reaction with 2-chloro-4,6-diphenyl-1,3,5-triazine or 1-bromo-4-(benzenesulfonyl)benzene, respectively.
A manufacturing method comprising the steps of: Use of a neutral iridium complex coordinated with the biphenyl derivative according to claim 1 in the manufacture of an organic electronic device. the organic electronic device is one or more of an organic light emitting diode, an organic solar cell, an organic light emitting cell, an organic field effect transistor, an organic laser, an organic spintronic device, an organic sensor, and an organic plasmon emitting diode;
4. The use according to claim 3. The mass concentration of the neutral iridium complex coordinated with the biphenyl derivative in the matrix is 3 to 10 wt %.
4. The use according to claim 3. The present invention relates to a neutral iridium complex having the biphenyl derivative according to claim 1 coordinated thereto.
An organic electronic device comprising: The mass concentration of the neutral iridium complex coordinated with the biphenyl derivative is 3 to 10 wt %.
7. The organic electronic device of claim 6.

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