KR102529930B1 - Novel Iridium complex and organic light emitting device comprising the same - Google Patents

Abstract

The present invention provides a novel iridium complex compound and an organic light emitting device using the same.

Description

Novel iridium complex and organic light emitting device using the same

The present invention relates to a novel iridium complex compound and an organic light emitting device including the same.

In general, the organic light emitting phenomenon refers to a phenomenon in which electrical energy is converted into light energy using an organic material. An organic light emitting device using an organic light emitting phenomenon has a wide viewing angle, excellent contrast, and a fast response time, and has excellent luminance, driving voltage, and response speed characteristics, and thus many studies are being conducted.

An organic light emitting device generally has a structure including an anode, a cathode, and an organic material layer between the anode and the cathode. In order to increase the efficiency and stability of the organic light emitting device, the organic material layer is often composed of a multi-layered structure composed of different materials, and may include, for example, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer. In the structure of this organic light emitting device, when a voltage is applied between the two electrodes, holes are injected from the anode and electrons from the cathode are injected into the organic material layer, and when the injected holes and electrons meet, excitons are formed. When it falls back to the ground state, it glows.

The development of new materials for organic materials used in the organic light emitting device as described above is continuously required.

Meanwhile, in recent years, an organic light emitting device using a solution process, particularly an inkjet process, instead of a conventional deposition process has been developed to reduce process costs. In the early days, an attempt was made to develop an organic light emitting device by coating all organic light emitting device layers with a solution process, but the current technology has limitations, so only HIL, HTL, and EML in the form of a regular structure are carried out as a solution process, and the subsequent process is the existing deposition process A hybrid process that utilizes is being studied.

Accordingly, the present invention provides a novel organic light emitting device material that can be used in an organic light emitting device and can be used in a solution process at the same time.

Korean Patent Publication No. 10-2000-0051826

The present invention relates to a novel iridium complex compound and an organic light emitting device including the same.

The present invention provides an iridium complex compound represented by Formula 1 below:

[Formula 1]

In Formula 1,

R ₁ and R ₂ are each independently hydrogen; Substituted or unsubstituted C _1-60 Alkyl; or substituted or unsubstituted C _1-60 haloalkyl; Substituted or unsubstituted C _6-60 aryl; Or a C _2-60 heteroaryl containing one or more heteroatoms selected from the group consisting of substituted or unsubstituted N, O and S,

는 하기 화학식 2a 내지 2d로 구성되는 군으로부터 선택되는 어느 하나이고,

Is any one selected from the group consisting of Formulas 2a to 2d,

[Formula 2a]

[Formula 2b]

[Formula 2c]

[Formula 2d]

In Formulas 2a to 2d,

R ₁₁ to R ₁₉ are each independently hydrogen; heavy hydrogen; halogen; cyano; nitro; amino; Substituted or unsubstituted C _1-60 Alkyl; Substituted or unsubstituted C _1-60 haloalkyl; Substituted or unsubstituted C _1-60 alkoxy; Substituted or unsubstituted C _1-60 haloalkoxy; Substituted or unsubstituted C _3-60 cycloalkyl; Substituted or unsubstituted C _2-60 alkenyl; Substituted or unsubstituted C _6-60 aryl; substituted or unsubstituted C _6-60 aryloxy; Or a C _2-60 heteroaryl containing one or more heteroatoms selected from the group consisting of substituted or unsubstituted N, O and S,

a1 to a6 are each independently an integer of 0 to 2;

* is a linking site with Ir.

In addition, the present invention is a first electrode; a second electrode provided to face the first electrode; and one or more organic material layers provided between the first electrode and the second electrode, wherein at least one of the organic material layers includes an iridium complex represented by Chemical Formula 1. do.

The iridium complex represented by Formula 1 described above can be used as a material for an organic layer of an organic light emitting device, and can also be used as a solution process, and can improve efficiency in an organic light emitting device, and an efficiency roll-off phenomenon at high current. can reduce

1 shows an example of an organic light emitting device composed of a substrate 1, an anode 2, a light emitting layer 3, and a cathode 4.
2 shows an example of an organic light emitting device composed of a substrate (1), an anode (2), a hole injection layer (5), a hole transport layer (6), a light emitting layer (7), an electron transport layer (8), and a cathode (4). it did
3 shows UV-Vis absorption spectra and PL spectra of Ir complex compounds Ir1, Ir2, and Ir3 prepared in Preparation Example, respectively.
4 shows AFM images of spin-coated films of Ir complex compounds Ir1, Ir2, and Ir3 prepared in Preparation Example, respectively.
5 is a current density-voltage-luminance (JVL) graph, a graph of current efficiency and photoluminescence characteristics according to current density, a graph of external quantum efficiency according to luminance, and an EL spectrum of organic light emitting devices A, B, and C prepared in Example. are shown respectively.
6 shows current density-voltage-luminance (JVL) graphs, current efficiency and photoluminescence characteristic graphs according to current density, and external quantum efficiency graphs according to luminance of organic light emitting devices D, E, and F prepared in Example. will be.
7 shows a current density-voltage-luminance (JVL) graph, a graph of current efficiency and photoluminescence characteristics according to current density, a graph of external quantum efficiency according to luminance, and an EL spectrum of the organic light emitting device G prepared in Example. .

Hereinafter, in order to aid understanding of the present invention, it will be described in more detail.

는 다른 치환기에 연결되는 결합을 의미한다.In this specification,

means a bond connected to another substituent.

In this specification, the term "substituted or unsubstituted" means deuterium; halogen group; cyano group; nitro group; hydroxy group; carbonyl group; ester group; imide group; amino group; phosphine oxide group; alkoxy group; aryloxy group; Alkyl thioxy group; Arylthioxy group; an alkyl sulfoxy group; aryl sulfoxy groups; silyl group; boron group; an alkyl group; cycloalkyl group; alkenyl group; aryl group; aralkyl group; Aralkenyl group; Alkyl aryl group; Alkylamine group; Aralkylamine group; heteroarylamine group; Arylamine group; Arylphosphine group; Or substituted or unsubstituted with one or more substituents selected from the group consisting of heteroaryl containing at least one of N, O, and S atoms, or substituted or unsubstituted with two or more substituents linked to each other among the substituents exemplified above. . For example, "a substituent in which two or more substituents are connected" may be a biphenyl group. That is, the biphenyl group may be an aryl group or may be interpreted as a substituent in which two phenyl groups are connected.

In the present specification, the number of carbon atoms of the carbonyl group is not particularly limited, but is preferably 1 to 40 carbon atoms. Specifically, it may be a compound having the following structure, but is not limited thereto.

In the present specification, the ester group may be substituted with an aryl group having 6 to 25 carbon atoms or a straight-chain, branched-chain or cyclic chain alkyl group having 1 to 25 carbon atoms in the ester group. Specifically, it may be a compound of the following structural formula, but is not limited thereto.

In the present specification, the number of carbon atoms of the imide group is not particularly limited, but is preferably 1 to 25 carbon atoms. Specifically, it may be a compound having the following structure, but is not limited thereto.

In the present specification, the silyl group is specifically a trimethylsilyl group, a triethylsilyl group, a t-butyldimethylsilyl group, a vinyldimethylsilyl group, a propyldimethylsilyl group, a triphenylsilyl group, a diphenylsilyl group, a phenylsilyl group, and the like. but not limited to

In the present specification, the boron group specifically includes a trimethyl boron group, a triethyl boron group, a t-butyldimethyl boron group, a triphenyl boron group, a phenyl boron group, but is not limited thereto.

In this specification, examples of the halogen group include fluorine, chlorine, bromine or iodine.

In the present specification, the alkyl group may be straight-chain or branched-chain, and the number of carbon atoms is not particularly limited, but is preferably 1 to 40. According to one embodiment, the number of carbon atoms of the alkyl group is 1 to 20. According to another exemplary embodiment, the number of carbon atoms of the alkyl group is 1 to 10. According to another exemplary embodiment, the alkyl group has 1 to 6 carbon atoms. Specific examples of the alkyl group include methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl, pentyl, n -pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl , n-heptyl, 1-methylhexyl, cyclopentylmethyl, cyclohexylmethyl, octyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2 -Dimethylheptyl, 1-ethyl-propyl, 1,1-dimethyl-propyl, isohexyl, 2-methylpentyl, 4-methylhexyl, 5-methylhexyl, etc., but is not limited thereto.

In the present specification, the alkenyl group may be linear or branched, and the number of carbon atoms is not particularly limited, but is preferably 2 to 40. According to one embodiment, the alkenyl group has 2 to 20 carbon atoms. According to another exemplary embodiment, the alkenyl group has 2 to 10 carbon atoms. According to another exemplary embodiment, the alkenyl group has 2 to 6 carbon atoms. Specific examples include vinyl, 1-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 3-methyl-1- Butenyl, 1,3-butadienyl, allyl, 1-phenylvinyl-1-yl, 2-phenylvinyl-1-yl, 2,2-diphenylvinyl-1-yl, 2-phenyl-2-( naphthyl-1-yl)vinyl-1-yl, 2,2-bis(diphenyl-1-yl)vinyl-1-yl, stilbenyl group, styrenyl group, etc., but is not limited thereto.

In the present specification, the cycloalkyl group is not particularly limited, but preferably has 3 to 60 carbon atoms, and according to an exemplary embodiment, the cycloalkyl group has 3 to 30 carbon atoms. According to another exemplary embodiment, the number of carbon atoms of the cycloalkyl group is 3 to 20. According to another exemplary embodiment, the number of carbon atoms of the cycloalkyl group is 3 to 6. Specifically, cyclopropyl, cyclobutyl, cyclopentyl, 3-methylcyclopentyl, 2,3-dimethylcyclopentyl, cyclohexyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 2,3-dimethylcyclohexyl, 3, 4,5-trimethylcyclohexyl, 4-tert-butylcyclohexyl, cycloheptyl, cyclooctyl, and the like, but are not limited thereto.

In the present specification, the aryl group is not particularly limited, but preferably has 6 to 60 carbon atoms, and may be a monocyclic aryl group or a polycyclic aryl group. According to one embodiment, the number of carbon atoms of the aryl group is 6 to 30. According to one embodiment, the number of carbon atoms of the aryl group is 6 to 20. The aryl group may be a phenyl group, a biphenyl group, a terphenyl group, etc. as a monocyclic aryl group, but is not limited thereto. The polycyclic aryl group may be a naphthyl group, anthracenyl group, phenanthryl group, pyrenyl group, perylenyl group, chrysenyl group, fluorenyl group, and the like, but is not limited thereto.

등이 될 수 있다. 다만, 이에 한정되는 것은 아니다.In the present specification, the fluorenyl group may be substituted, and two substituents may be bonded to each other to form a spiro structure. When the fluorenyl group is substituted,

etc. However, it is not limited thereto.

In the present specification, heteroaryl is a heteroaryl containing at least one of O, N, Si, and S as a heterogeneous element, and the number of carbon atoms is not particularly limited, but preferably has 2 to 60 carbon atoms. Examples of the heteroaryl include a thiophene group, a furan group, a pyrrole group, an imidazole group, a thiazole group, an oxazole group, an oxadiazole group, a triazole group, a pyridyl group, a bipyridyl group, a pyrimidyl group, a triazine group, a triazole group, a Cridyl group, pyridazinyl group, pyrazinyl group, quinolinyl group, quinazoline group, quinoxalinyl group, phthalazinyl group, pyridopyrimidinyl group, pyridopyrazinyl group, pyrazinopyrazinyl group, isoquinoline group, Indole group, carbazole group, benzoxazole group, benzoimidazole group, benzothiazole group, benzocarbazole group, benzothiophene group, dibenzothiophene group, benzofuranyl group, phenanthroline group, thiazolyl group, iso An oxazolyl group, an oxadiazolyl group, a thiadiazolyl group, a benzothiazolyl group, a phenothiazinyl group, and a dibenzofuranyl group, but are not limited thereto.

In the present specification, an aralkyl group, an aralkenyl group, an alkylaryl group, and an aryl group among arylamine groups are the same as the examples of the aryl group described above. In the present specification, the alkyl group among the aralkyl group, the alkylaryl group, and the alkylamine group is the same as the examples of the above-mentioned alkyl group. In the present specification, the description of the above-described heteroaryl may be applied to the heteroaryl among heteroarylamines. In the present specification, the alkenyl group among the aralkenyl groups is the same as the examples of the alkenyl group described above. In the present specification, the description of the aryl group described above may be applied except that the arylene is a divalent group. In the present specification, the description of heteroaryl described above may be applied except that the heteroarylene is a divalent group. In the present specification, the hydrocarbon ring is not a monovalent group, and the description of the aryl group or cycloalkyl group described above may be applied, except that the hydrocarbon ring is formed by combining two substituents. In the present specification, the heterocyclic group is not a monovalent group, and the description of the above-described heteroaryl may be applied, except that it is formed by combining two substituents.

Meanwhile, the present invention provides an iridium complex compound represented by Chemical Formula 1 above.

The conventionally developed solution-processable green phosphorescent light emitting material has low photo-luminescent quantum yield (PLQY) and electroluminescence (EL) performance, and also has a roll-off (roll-off) that rapidly drops in efficiency at high current density. Efficiency roll-off has been a problem.

However, in the iridium (III) complex compound represented by Formula 1 according to the present invention, as will be described in detail below, a phenylpyridine derivative linked by an amide is used as the main ligand, and a picolinic acid derivative, a pyrazine-carboxylic acid derivative, tetra A phenyl imidodiphosphinate derivative or an acetylacetone derivative can be used to improve solubility in a solvent, thereby facilitating the formation of a light emitting layer in a solution process, and at the same time, luminous quantum efficiency of an organic light emitting device and efficiency at high current density The roll-off phenomenon can be improved.

Specifically, suitable soluble substituents (solubilizing group), for example, alkoxy (CH ₃ (CH ₂ ) _n O-, n is an integer from 0 to 5), alkyloxyalkoxy (CH ₃ (CH ₂ ) _n O (CH ₂ ) _m O-, n is an integer from 0 to 5, m is an integer from 1 to 5), etc. are introduced into auxiliary ligands, in the case of complex compounds represented by Formula 1, not only solubility in solvents is improved, but also employing them PLQY and EL performance of an organic light emitting device can be improved. In addition, in the case of an organic light emitting device employing a complex compound represented by Formula 1 using a tetraphenyl imidodiphosphinate derivative as an auxiliary ligand and having a bulky substituent at the R ₂ position of the main ligand, self-quenching and the hole-electron balance in charge injection is improved, so that the efficiency roll-off phenomenon of the organic light emitting diode can be significantly reduced.

The iridium complex represented by Formula 1 may be represented by Formula 1-1 below:

[Formula 1-1]

에 대한 설명은 상기 화학식 1에서 정의한 바와 같다.In Formula 1-1, R ₁ , R ₂ and

Description is as defined in Formula 1 above.

In addition, R ₁ and R ₂ are each independently hydrogen; Substituted or unsubstituted C _1-10 Alkyl; Or it may be a substituted or unsubstituted C _1-10 haloalkyl.

For example, R ₁ is unsubstituted; or C _1-10 alkyl substituted with methyl or ethyl, and R ₂ may be unsubstituted C _1-10 haloalkyl.

Specifically, for example, R ₁ is methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, sec-butyl, pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, 1-methylhexyl, 2-methylhexyl, 3-methylhexyl, 4-methylhexyl, 5-methylhexyl, 1-ethylhexyl, 2-ethylhexyl, 3-ethylhexyl, 4-ethylhexyl, or heptyl;

R ₂ can be trifluoromethyl, trichloromethyl, or tribromomethyl.

In addition, R ₁₁ to R ₁₉ are each independently hydrogen; heavy hydrogen; halogen; C _1-10 alkyl unsubstituted or substituted with alkoxy; or C _1-10 alkoxy which is unsubstituted or substituted with alkoxy.

For example, R ₁₁ to R ₁₉ may each independently be hydrogen, CH ₃ (CH ₂ ) _n O-, or CH ₃ (CH ₂ ) _n O(CH ₂ ) _m O-, where n is each independently an integer from 0 to 5, and m is an integer from 1 to 5.

Specifically, for example, R ₁₁ to R ₁₉ are each independently hydrogen, halogen, methoxy, ethoxy, propoxy, butoxy, methoxymethoxy, ethoxymethoxy, 2-methoxyethoxy, 2 -ethoxyethoxy, 3-methoxypropoxy, 3-ethoxypropoxy, or 3-propoxypropoxy.

는 하기 화학식 3a 내지 3e로 구성되는 군으로부터 선택될 수 있다: also,

May be selected from the group consisting of Formulas 3a to 3e:

[Formula 3a]

[Formula 3b]

[Formula 3c]

[Formula 3d]

[Formula 3e]

In Formulas 3a to 3e,

Descriptions of R ₁₁ to R ₁₈ are as defined in Chemical Formulas 2a to 2d, and * is a linking site with Ir.

For example, R ₁₁ to R ₁₈ are each independently hydrogen, methoxy, ethoxy, propoxy, butoxy, methoxymethoxy, ethoxymethoxy, 2-methoxyethoxy, 2-ethoxy oxy, 3-methoxypropoxy, 3-ethoxypropoxy, or 3-propoxypropoxy.

In addition, the iridium complex compound may be represented by one of Chemical Formulas 4a to 4e:

[Formula 4a]

[Formula 4b]

[Formula 4c]

[Formula 4d]

[Formula 4e]

In Formulas 4a to 4e,

R ₁ , R ₂ and R ₁₁ to R ₁₈ are described as defined in Formula 1 above.

Meanwhile, the compound may be selected from the group consisting of the following compounds.

Meanwhile, the compound represented by Chemical Formula 1 may be prepared by introducing an auxiliary ligand after synthesizing a main ligand and preparing a dimer with iridium. This manufacturing method may be more specific in Preparation Examples to be described later.

For example, the compounds represented by Chemical Formulas 4a, 4d and 4e can be prepared by, for example, the following Reaction Scheme 1, and other compounds are appropriately selected starting materials according to the structure of the compound to be prepared by referring to the following Reaction Scheme 1. can be produced as a substitute.

[Scheme 1]

In Reaction Scheme 1, R ₁ , R ₂ , R ₁₁ and R ₁₃ to R ₁₈ are described as defined in Formula 1 above.

Meanwhile, the present invention provides a coating composition comprising the iridium complex represented by Chemical Formula 1 and a solvent. The iridium complex represented by Chemical Formula 1 has excellent solubility in a solvent, and thus an organic material layer of an organic light emitting device, particularly a light emitting layer, which will be described later, can be formed through a solution process.

The solvent is not particularly limited as long as it can dissolve or disperse the iridium complex, and examples thereof include chloroform, dichloromethane, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, chlorobenzene, chlorine-based solvents such as o-dichlorobenzene; ether solvents such as tetrahydrofuran and dioxane; aromatic hydrocarbon solvents such as toluene, xylene, trimethylbenzene, and mesitylene; aliphatic hydrocarbon-based solvents such as cyclohexane, methylcyclohexane, n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane; Ketone solvents, such as acetone, methyl ethyl ketone, and cyclohexanone; Ester solvents, such as ethyl acetate, butyl acetate, and ethyl cellosolve acetate; Ethylene glycol, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, dimethoxyethane, propylene glycol, diethoxymethane, triethylene glycol monoethyl ether, glycerin, 1,2-hexanediol, etc. alcohol and its derivatives; alcohol solvents such as methanol, ethanol, propanol, isopropanol, and cyclohexanol; sulfoxide solvents such as dimethyl sulfoxide; and amide solvents such as N-methyl-2-pyrrolidone and N,N-dimethylformamide; benzoate solvents such as butyl benzoate and methyl-2-methoxy benzoate; tetralin; and solvents such as 3-phenoxy-toluene. In addition, the above-mentioned solvent may be used alone or in combination of two or more solvents.

In addition, the present invention provides a method of forming a light emitting layer using the coating composition described above. Specifically, coating the above-described coating composition on an anode or on a hole transport layer and/or an electron control layer formed on the anode by a solution process; and heat-treating the coated coating composition.

The solution process uses the above-described coating composition according to the present invention, and includes spin coating, dip coating, doctor blading, inkjet printing, screen printing, spraying, roll coating, etc., but is not limited thereto.

In the heat treatment step, the heat treatment temperature is preferably about 100°C. In addition, the heat treatment time is 1 minute to 1 hour, more preferably 10 minutes to 30 minutes. In addition, the heat treatment is preferably performed in an inert gas atmosphere such as argon or nitrogen. In addition, a step of evaporating a solvent may be further included between the coating step and the heat treatment step.

Meanwhile, the present invention provides an organic light emitting device including the iridium complex represented by Formula 1 above. In one example, the present invention provides a first electrode; a second electrode provided to face the first electrode; and one or more organic material layers provided between the first electrode and the second electrode, wherein at least one of the organic material layers includes an iridium complex represented by Chemical Formula 1. do.

The organic material layer of the organic light emitting device of the present invention may have a single-layer structure, or may have a multi-layer structure in which two or more organic material layers are stacked. For example, the organic light emitting device of the present invention may have a structure including a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer as organic material layers. However, the structure of the organic light emitting device is not limited thereto and may include fewer organic layers.

The organic material layer of the organic light emitting device of the present invention may have a single-layer structure, or may have a multi-layer structure in which two or more organic material layers are stacked. For example, the organic light emitting device of the present invention further includes a hole injection layer and a hole transport layer between the first electrode and the light emitting layer, and an electron transport layer and an electron injection layer between the light emitting layer and the second electrode, in addition to the light emitting layer as an organic material layer. can have a structure that However, the structure of the organic light emitting device is not limited thereto and may include fewer or more organic layers.

Also, the organic layer may include a light emitting layer, and the light emitting layer may include the iridium complex compound represented by Chemical Formula 1. In particular, the iridium complex compound represented by Chemical Formula 1 may be used as a dopant for the light emitting layer. For example, the iridium complex represented by Chemical Formula 1 may be used as a green phosphorescent dopant.

Also, the organic light emitting device according to the present invention may be a normal type organic light emitting device in which an anode, one or more organic material layers, and a cathode are sequentially stacked on a substrate. In addition, the organic light emitting device according to the present invention may be an organic light emitting device of an inverted type in which a cathode, one or more organic material layers, and an anode are sequentially stacked on a substrate. For example, the structure of an organic light emitting device according to an embodiment of the present invention is illustrated in FIGS. 1 and 2 .

1 shows an example of an organic light emitting device composed of a substrate 1, an anode 2, a light emitting layer 3, and a cathode 4. In this structure, the compound represented by Chemical Formula 1 may be included in the light emitting layer.

2 shows an example of an organic light emitting device composed of a substrate (1), an anode (2), a hole injection layer (5), a hole transport layer (6), a light emitting layer (7), an electron transport layer (8), and a cathode (4). it did In this structure, the compound represented by Formula 1 may be included in at least one layer of the hole injection layer, the hole transport layer, the light emitting layer, and the electron transport layer.

The organic light emitting device according to the present invention may be manufactured with materials and methods known in the art, except that at least one of the organic material layers includes the compound represented by Chemical Formula 1. Also, when the organic light emitting device includes a plurality of organic material layers, the organic material layers may be formed of the same material or different materials.

For example, the organic light emitting device according to the present invention may be manufactured by sequentially stacking a first electrode, an organic material layer, and a second electrode on a substrate. At this time, by using a physical vapor deposition (PVD) method such as sputtering or e-beam evaporation, depositing a metal or a metal oxide having conductivity or an alloy thereof on the substrate to form an anode After forming an organic material layer including a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer thereon, it can be prepared by depositing a material that can be used as a cathode thereon. In addition to this method, an organic light emitting device may be manufactured by sequentially depositing a cathode material, an organic material layer, and an anode material on a substrate.

In addition to this method, an organic light emitting device may be manufactured by sequentially depositing an organic material layer and an anode material on a substrate from a cathode material (WO 2003/012890). However, the manufacturing method is not limited thereto.

In one example, the first electrode is an anode and the second electrode is a cathode, or the first electrode is a cathode and the second electrode is an anode.

As the anode material, a material having a high work function is generally preferred so that holes can be smoothly injected into the organic material layer. Specific examples of the cathode material include metals such as vanadium, chromium, copper, zinc, and gold or alloys thereof; metal oxides such as zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO); combinations of metals and oxides such as ZnO:Al or SNO ₂ :Sb; Conductive polymers such as poly(3-methylthiophene), poly[3,4-(ethylene-1,2-dioxy)thiophene] (PEDOT), polypyrrole, and polyaniline, but are not limited thereto.

The cathode material is preferably a material having a small work function so as to easily inject electrons into the organic material layer. Specific examples of the anode material include metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, and lead, or alloys thereof; There are multi-layered materials such as LiF/Al or LiO ₂ /Al, but are not limited thereto.

The hole injection layer is a layer for injecting holes from the electrode, and the hole injection material has the ability to transport holes and has a hole injection effect at the anode, an excellent hole injection effect for the light emitting layer or the light emitting material, and generated in the light emitting layer A compound that prevents migration of excitons to the electron injecting layer or electron injecting material and has excellent thin film formation ability is preferred. It is preferable that the highest occupied molecular orbital (HOMO) of the hole injection material is between the work function of the anode material and the HOMO of the surrounding organic layer. Specific examples of the hole injection material include metal porphyrins, oligothiophenes, arylamine-based organic materials, hexanitrilehexaazatriphenylene-based organic materials, quinacridone-based organic materials, and perylene-based organic materials. of organic matter, anthraquinone, and polyaniline and polythiophene-based conductive polymers, but are not limited thereto.

The hole transport layer is a layer that receives holes from the hole injection layer and transports the holes to the light emitting layer. The hole transport material is a material that can receive holes from the anode or the hole injection layer and transfer them to the light emitting layer, and has high hole mobility. material is suitable. Specific examples include, but are not limited to, arylamine-based organic materials, conductive polymers, and block copolymers having both conjugated and non-conjugated parts.

The light emitting material is a material capable of emitting light in the visible ray region by receiving and combining holes and electrons from the hole transport layer and the electron transport layer, respectively, and a material having good quantum efficiency for fluorescence or phosphorescence is preferable. Specific examples include 8-hydroxy-quinoline aluminum complex (Alq ₃ ); carbazole-based compounds; dimerized styryl compounds; BAlq; 10-hydroxybenzoquinoline-metal compounds; compounds of the benzoxazole, benzthiazole and benzimidazole series; poly(p-phenylenevinylene) (PPV)-based polymers; spiro compounds; Polyfluorene, rubrene, etc., but are not limited thereto.

As described above, the light emitting layer may include a host material and a dopant material. The host material may further include a condensed aromatic ring derivative or a compound containing a hetero ring. Specifically, condensed aromatic ring derivatives include anthracene derivatives, pyrene derivatives, naphthalene derivatives, pentacene derivatives, phenanthrene compounds, fluoranthene compounds, etc., and heterocyclic-containing compounds include carbazole derivatives, dibenzofuran derivatives, ladder type furan compounds, pyrimidine derivatives, etc., but are not limited thereto.

Dopant materials include aromatic amine derivatives, strylamine compounds, boron complexes, fluoranthene compounds, metal complexes, and the like. Specifically, aromatic amine derivatives are condensed aromatic ring derivatives having a substituted or unsubstituted arylamino group, such as pyrene, anthracene, chrysene, periplanthene, etc. having an arylamino group, and styrylamine compounds include substituted or unsubstituted arylamine is substituted with at least one arylvinyl group, wherein one or two or more substituents selected from the group consisting of an aryl group, a silyl group, an alkyl group, a cycloalkyl group, and an arylamino group are substituted or unsubstituted. Specifically, there are styrylamine, styryldiamine, styryltriamine, styryltetraamine, etc., but is not limited thereto. In addition, metal complexes include, but are not limited to, iridium complexes and platinum complexes.

The electron transport layer is a layer that receives electrons from the electron injection layer and transports electrons to the light emitting layer. The electron transport material is a material that can receive electrons from the cathode and transfer them to the light emitting layer, and a material with high electron mobility Suitable. Specific examples include Al complexes of 8-hydroxyquinoline; Complexes containing Alq ₃ ; organic radical compounds; hydroxyflavone-metal complexes and the like, but are not limited thereto. The electron transport layer can be used with any desired cathode material as used according to the prior art. In particular, examples of suitable cathode materials are conventional materials having a low work function followed by a layer of aluminum or silver. Specifically cesium, barium, calcium, ytterbium and samarium, followed in each case by a layer of aluminum or silver.

The electron injection layer is a layer for injecting electrons from an electrode, has the ability to transport electrons, has an excellent electron injection effect from a cathode, an excellent electron injection effect for a light emitting layer or a light emitting material, and injects holes of excitons generated in the light emitting layer. A compound that prevents migration to a layer and has excellent thin film forming ability is preferred. Specifically, fluorenone, anthraquinodimethane, diphenoquinone, thiopyran dioxide, oxazole, oxadiazole, triazole, imidazole, perylenetetracarboxylic acid, preonylidene methane, anthrone, etc. and their derivatives, metals complex compounds and nitrogen-containing 5-membered ring derivatives, but are not limited thereto.

Examples of the metal complex compound include 8-hydroxyquinolinato lithium, bis(8-hydroxyquinolinato)zinc, bis(8-hydroxyquinolinato)copper, bis(8-hydroxyquinolinato)manganese, Tris(8-hydroxyquinolinato) aluminum, tris(2-methyl-8-hydroxyquinolinato) aluminum, tris(8-hydroxyquinolinato) gallium, bis(10-hydroxybenzo[h] Quinolinato) beryllium, bis(10-hydroxybenzo[h]quinolinato)zinc, bis(2-methyl-8-quinolinato)chlorogallium, bis(2-methyl-8-quinolinato)( There are o-cresolato) gallium, bis(2-methyl-8-quinolinato)(1-naphtolato)aluminum, and bis(2-methyl-8-quinolinato)(2-naphtolato)gallium. Not limited to this.

The organic light emitting device according to the present invention may be a top emission type, a bottom emission type, or a double side emission type depending on the material used.

In addition, the compound represented by Chemical Formula 1 may be included in an organic solar cell or an organic transistor in addition to an organic light emitting device.

Preparation of the iridium complex represented by Chemical Formula 1 and the organic light emitting device including the same will be described in detail in the following examples. However, the following examples are intended to illustrate the present invention, and the scope of the present invention is not limited thereto.

manufacturing example 1: iridium complex Ir1 manufacturing

Step 1-1: Compound 2- Chloro -N- methylpyridine -3- of amine (a) manufacturing

3-Amino-2-chloro in tetrahydrofuran (50 mL) anhydrous in a suspension of sodium hydride (NaH, 0.78 g, 19.2 mmol, 60% dispersion in oil) and tetrahydrofuran (THF, 50 mL) under a nitrogen atmosphere. A solution of pyridine (2.46 g, 19.2 mmol) was added. The reaction mixture was stirred at room temperature for 3 hours. Iodomethane (1.2 mL, 19.2 mmol) was then added to the reaction mixture, which was then heated at 40° C. for 9 hours. After heating and cooling to room temperature, the solvent was removed from the reaction mixture, and the crude material from which the solvent was removed was dissolved in dichloromethane (DCM) and filtered to remove excess salt. This filtrate was purified by silica gel column chromatography using ethyl acetate (EtOAc):n-hexane (10:90%, v/v) as the eluent to obtain the title compound as a pale yellow liquid.

Yield: 62% (1.52 g)

¹ H NMR (300 MHz, CDCl _{3 ,} δ): 7.72 (d, 1H), 7.18-7.0 (m, 1H), 6.8 (d, 1H), 4.2 (s, 1H), 3.16 (d, 3H).

Step 1-2: Compound N-(2- Chloropyridine -3-days)-N- methyl -3-( trifluoromethyl ) Preparation of benzamide (b)

NaH (2.8 g, 7.1 mmol) was added to THF anhydride (30 mL) under a nitrogen atmosphere, which was cooled to 0 °C to obtain a reaction mixture. To the reaction mixture was added compound (a) (5 g, 3.5 mmol) prepared in step 1-1 above, and stirred for 1 hour. Then, 3-(trifluoromethyl)benzoyl chloride (10.97 g, 52.59 mmol) was added to the reaction mixture and stirred at room temperature for 8 hours. After the reaction was complete, water (50 mL) was added to the reaction mixture to terminate the reaction. Finally, the organic layer was extracted with DCM from the prepared reactant, washed with brine solution, and then dried over anhydrous Na ₂ SO ₄ . Then the solvent was evaporated and the solid residue was purified by silica gel column chromatography using EtOAc:n-hexane (20:80%, v/v) as the eluent to give the title compound as a white solid.

Yield: 70% (3.5 g)

¹ H NMR (300 MHz, CDCl _{3 ,} δ): 8.25 (s, 1H), 7.63 (s, 1H), 7.54 (d, 3H), 7.38-7.29 (s, 1H), 7.18 (s, 1H) 3.33 (s, 3H).

Step 1-3: Compound 5- methyl -8- (trifluoromethyl)benzo[c][1, 5] naphthyridine Preparation of -6(5H)-one (c)

Compound (b) prepared in step 1-2 (2 g, 6.0 mmol), Pd(PPh ₃ ) ₄ (0.7 g, 0.59 mmol), Na ₂ CO ₃ (3.18 g, 30 mmol), and 2-(dimethylamino)ethyl methacrylate (DMA, 30 mL) was heated at 150° C. for 4 h. Afterwards, the reaction mixture was cooled to room temperature and water (50 mL) was added. After extracting the organic layer of the resulting mixture with DCM (100 mL), it was Na ₂ SO ₄ dried over anhydrous. Then, the solvent was evaporated and the solid residue was purified by silica gel column chromatography using EtOAc:n-hexane (8:92%, v/v) as the eluent to give the title compound as a white solid.

Yield: 75% (1.5 g)

¹ H NMR (300 MHz, CDCl _{3 ,} δ): 8.96 (s, 1H), 8.80 (s, 1H), 8.62 (s, 1H), 8.05 (s, 1H), 7.77 (d, 1H), 7.58 ( s, 1H) 3.88 (s, 3H).

Steps 1-4: Iridium dimer Preparation of complex compound (j)

Compound (c) (1.5 g, 53.91 mmol) prepared in step 1-3 and IrCl ₃ 3H ₂ O (0.76 g, 134.77 mmol) were mixed with a mixture of 2-ethoxyethanol and water (40 mL, 3:1 v /v) was added. The reaction mixture was stirred at 140° C. for 20 hours to obtain a yellow precipitate which was then cooled to room temperature. After filtering the precipitate, it was washed with water (60 mL) and methanol (10 mL), and then dried under vacuum to obtain the compound as a yellow solid.

Steps 1-5: according to tandem reaction bis [5- methyl -8- trifluoromethyl -5H-benzo(c)(1,5)naphthyridin-6-one](4-(2-ethoxyethoxy picolinate ) Preparation of iridium (III) (Ir1)

Compound (j) prepared in steps 1-4 above (1 g, 0.63 mmol), 4-chloropicolinic acid (0.504 g, 3.19 mmol) and Na ₂ CO in 2-ethoxyethanol (25 ml) under a nitrogen atmosphere. A solution of ₃ (0.67 g, 6.39 mmol) was stirred at 140 °C for 12 h. After cooling to room temperature, the reaction mixture was poured into water and extracted with DCM. The extracted organic layer was mixed with Na ₂ SO ₄ After drying to anhydrous and concentration in vacuo, the obtained residue was purified by silica gel column chromatography using methanol (MeOH): EtOAc (30:70%, v/v) as eluent to give the title compound as a yellow solid got it

Yield: 50% (0.5 g).

^1H NMR (300 MHz, CDCl _{3 ,} δ): 8.70 (d, J = 5.4 Hz, 1H), 8.18 (s, 1H), 8.12 (s, 1H), 7.86 (d, J = 2.6 Hz, 1H) , 7.76 (d, J = 8.6 Hz, 2H), 7.57 - 7.52 (m, 1H), 7.44 (d, J = 5.6 Hz, 2H), 7.38 - 7.33 (m, 1H), 6.93 - 6.90 (m, 1H) ), 6.83 (s, 1H), 6.62 (s, 1H), 4.25 (d, J = 2.9 Hz, 2H), 3.84 (s, 6H), 3.79 - 3.76 (m, 2H), 3.56 (q, J = 7.0 Hz, 2H), 1.20 (t, J = 7.0 Hz, 3H).

¹³ C NMR (75 MHz, CDCl ₃ , δ): 173.0, 167.0, 161.5, 161.4, 153.5, 150.3, 149.2, 148.8, 147.1, 144.9, 142.9, 142.0, 135.3, 134.8, 1 32.4, 132.0, 131.9, 131.5, 131.2 131.2, 130.8, 130.7, 126.7, 126.4, 125.5, 125.4, 124.7, 124.5, 123.1, 123.0, 121.9, 121.8, 118.6, 118.6, 118.0, 118.0, 116.7, 113.7, 68.9, 68.1, 67.1, 30.0, 29.9, 15.2 .

manufacturing example 2: iridium complex compound Ir2 manufacturing

Step 2-1: Compound 2- Chloro -N-(2- ethylhexyl )pyridine-3- of amine (d) manufacturing

A solution of 3-amino-2-chloropyridine (5 g, 38.89 mmol) in THF anhydride (50 mL) was dissolved in a suspension of NaH (1.65 g, 38.89 mmol, 60% dispersion in oil) in THF (50 mL) under a nitrogen atmosphere. added. After the reaction mixture was stirred at room temperature for 3 hours, 2-ethylhexyl bromide (5.78 mL, 38.89 mmol) was added and heated at 40° C. for 9 hours. After cooling to room temperature, the solvent was removed, and the crude material from which the solvent was removed was dissolved in DCM and then filtered to remove excess salt. This filtrate was purified by silica gel column chromatography using ethyl acetate (EtOAc):n-hexane (10:60%, v/v) as the eluent to obtain the title compound as a pale yellow liquid.

Yield: 62% (3.1 g)

¹ H NMR (300 MHz, CDCl ₃ , δ): 7.64-7.63 (d, 1H), 7.06-7.02 (m, 1H), 6.84-6.81 (d, 1H), 4.33 (s, 1H), 3.01 (t , 2H), 1.57–1.55 (d, 1H), 1.41–1.28 (m, 8H), 0.87 (m, 6H).

Step 2-2: Compound N-(2- Chloropyridine -3-day)-N-(2- ethylhexyl )-3-( trifluoromethyl ) Preparation of benzamide (e)

NaH (1.39 g, 58.14 mmol) was added to anhydrous THF (30 mL) under a nitrogen atmosphere and then the mixture was cooled to 0 °C. Compound (d) (5 g, 29.07 mmol) prepared in step 2-1 was added to the reactant, and stirred for 1 hour. Then, 3-(trifluoromethyl)benzoyl chloride (9.09 g, 43.61 mmol) was added to the reaction mixture and stirred at room temperature for 8 hours. After the reaction was complete, water (50 mL) was added to the reaction mixture to terminate the reaction. Finally, after extracting the organic layer from the prepared reactant with DCM, it was washed with brine solution and Na ₂ SO ₄ dried over anhydrous. Then the solvent was evaporated and the solid residue was purified by silica gel column chromatography using EtOAc:n-hexane (10:40%, v/v) as eluent to give the title compound as a white solid.

Yield: 70% (3.5 g).

^1H NMR (300 MHz, CDCl _{3 ,} δ): 8.25 (s, 1H), 7.45-7.56 (d, 4H), 7.32 (d, 1H), 7.18 (s, 1H), 7.18 (s, 1H), 4.15 (s, 1H), 3.25–3.23 (t, 1H), 1.32–1.22 (d, 8H), 0.98 (s, 6H).

Step 2-3: Compound 5-(2- ethylhexyl )-8- (trifluoromethyl)benzo[c][1,5]naphthyridine Preparation of -6(5H)-one (f)

Compound (e) prepared in step 2-2 (4 g, 10.62 mmol), Pd(PPh ₃ ) ₄ (0.6 g, 0.53 mmol), Na ₂ CO ₃ (3.18 g, 53.10 mmol), and DMA (30 mL) was heated at 150 °C for 4 h. Afterwards, the reaction mixture was cooled to room temperature and water (50 mL) was added. After extracting the organic layer of the resulting mixture with DCM (100 mL), it was Na ₂ SO ₄ dried over anhydrous. Then, the solvent was evaporated and the solid residue was purified by silica gel column chromatography using EtOAc:n-hexane (8:92%, v/v) as the eluent to give the title compound as a white solid.

Yield: 75% (3 g)

¹ H NMR (300 MHz, CDCl ₃ , δ): 8.99-8.96 (d, 1H), 8.79 (s, 1H), 8.61 (s, 1H), 8.03-8.01 (d, 1H), 7.73-7.70 (d , 1H), 7.51 (s, 1H), 4.38–4.27 (d, 2H), 1.90 (s, 1H), 1.40–1.29 (m, 8H), 0.94–0.87 (m, 6H).

Step 2-4: Iridium dimer Preparation of complex compound (k)

The title compound was prepared in the same manner, except that the compound (f) prepared in step 2-3 was used instead of the compound (c) prepared in step 1-3.

Steps 2-5: bis [5- ethylhexyl -8- trifluoromethyl -5H- Benzo(c)(1,5)naphthyridine -6-on] ( picolinate )Iridium(III)( Ir2 ) manufacture of

Compound (k) prepared in step 2-4 above (1 g, 0.63 mmol), 2-picolinic acid (0.504 g, 3.19 mmol) and Na ₂ CO ₃ in 2-ethoxyethanol (25 ml) under a nitrogen atmosphere. (0.67 g, 6.39 mmol) was stirred at 140 °C for 12 h. After cooling to room temperature, the reaction mixture was poured into water and extracted with DCM. The extracted organic layer was mixed with Na ₂ SO ₄ After drying to anhydrous and concentrating in vacuo, the resulting residue was purified by silica gel column chromatography using MeOH:EtOAc (40:60%, v/v) as eluent to give the title compound as a yellow solid.

Yield: 50% (0.5 g)

^1H NMR (300 MHz, CDCl _{3 ,} δ): 8.72 (d, J = 5.4 Hz, 1H), 8.38 (d, J = 7.7 Hz, 1H), 8.19 (s, 1H), 8.12 (s, 1H) , 7.99 (t, J = 7.7 Hz, 1H), 7.78 - 7.72 (m, 3H), 7.58 - 7.53 (m, 1H), 7.46 - 7.42 (m, 1H), 7.38 - 7.30 (m, 2H), 6.82 (s, 1H), 6.53 (s, 1H), 4.49 - 4.24 (m, 4H), 2.02 - 1.86 (m, 2H), 1.60 - 1.25 (m, 17H), 1.00 - 0.82 (m, 11H).

¹³ C NMR (75 MHz, CDCl ₃ , δ): 173.0, 167.0, 161.5, 161.4, 153.5, 150.3, 149.2, 148.8, 147.1, 144.9, 142.9, 142.0, 135.3, 134.8, 1 32.4, 132.0, 131.9, 131.5, 131.2 131.2, 130.8, 130.7, 126.7, 126.4, 125.5, 125.4, 124.7, 124.5, 123.1, 123.0, 121.9, 121.8, 118.6, 118.6, 118.0, 118.0, 116.7, 113.7, 68.9, 68.1, 67.1, 30.0, 29.9, 15.2 .

manufacturing example 3: iridium complex Ir3 manufacturing

Step 3-1: Compound 2- Chloro -N- hexylpyridine -3- of amines (g) manufacturing

A solution of 3-amino-2-chloropyridine (5 g, 38.9 mmol) in THF anhydride (50 mL) was dissolved in a suspension of NaH (1.5 g, 38.9 mmol, 60% dispersion in oil) in THF (50 mL) under a nitrogen atmosphere. added. This reaction mixture was stirred at room temperature for 3 hours. 1-Bromohexane (5.4 mL, 38.9 mmol) was then added thereto, and the reaction mixture was heated at 40° C. for 9 hours. After cooling to room temperature, the solvent was removed, and the crude material from which the solvent was removed was dissolved in DCM and then filtered to remove excess salt. This filtrate was purified by silica gel column chromatography using ethyl acetate (EtOAc):n-hexane (10:90%, v/v) as the eluent to obtain the title compound as a pale yellow liquid.

Yield: 62% (3.1 g)

¹ H NMR (300 MHz, CDCl _{3 ,} δ): 7.62-7.61 (d, 1H), 7.04-6.99 (m, 1H), 6.81-6.78 (d, 1H), 4.27 (s, 1H), 3.09-302 (q, 2H), 1.61–1.54 (m, 2H), 1.36–1.26 (6H, m), 0.86–0.82 (t, 3H).

Step 3-2: Compound N-(2- Chloropyridine -3-days)-N- hexyl -3-( trifluoromethyl ) Preparation of benzamide (h)

NaH (1.88 g, 47.41 mmol) was added to anhydrous THF (30 mL) under a nitrogen atmosphere and then the mixture was cooled to 0 °C. Compound (g) (7.353 g, 35.25 mmol) prepared in step 3-1 was added to the reaction mixture, and stirred for 1 hour. Then, 3-(trifluoromethyl)benzoyl chloride (7.353 g, 35.25 mmol) was added to the reaction mixture and stirred at room temperature for 8 hours. After the reaction was complete, water (50 mL) was added to the reaction mixture to terminate the reaction. Finally, after extracting the organic layer from the prepared reactant with DCM, it was washed with brine solution and Na ₂ SO ₄ dried over anhydrous. Then the solvent was evaporated and the solid residue was purified by silica gel column chromatography using EtOAc:n-hexane (10:40%, v/v) as eluent to give the title compound as a white solid.

Yield: 70% (3.5 g)

¹ H NMR (300 MHz, CDCl _{3 ,} δ): 8.24 (s, 1H), 7.54-7.46 (d, 4H), 7.27-7.25 (t, 1H), 7.17 (s, 1H), 4.12-4.07 (s , 1H), 3.59–3.49 (m, 1H), 1.59–1.56 (d, 2H), 1.27 (s, 6H), 0.84 (s, 3H).

Step 3-3: Compound 5- hexyl -8- (trifluoromethyl)benzo[c][1,5]naphthyridine Preparation of -6(5H)-one (i)

Compound (h) prepared in step 3-2 (4 g, 10.39 mmol), Pd(PPh ₃ ) ₄ (0.6 g, 0.519 mmol), Na ₂ CO ₃ (3.18 g, 51.97 mmol), and 2-( A mixture of dimethylamino)ethyl methacrylate (DMA, 30 mL) was heated at 150° C. for 4 hours. Afterwards, the reaction mixture was cooled to room temperature and water (50 mL) was added. After extracting the organic layer of the resulting mixture with DCM (100 mL), it was Na ₂ SO ₄ dried over anhydrous. Then, the solvent was evaporated and the solid residue was purified by silica gel column chromatography using EtOAc:n-hexane (10:60%, v/v) as an eluent to give the title compound as a white solid.

Yield: 75% (3 g)

¹ H NMR (300 MHz, CDCl ₃ , δ): 8.99-8.96 (d, 1H), 8.78 (s, 1H), 8.61 (s, 1H), 8.03-8.01 (d, 1H), 7.72-7.69 (d , 1H), 7.53 (m, 1H), 4.34–4.32 (m, 2H), 1.77–1.68 (m, 2H), 1.47–1.35 (m, 6H), 0.90 (s, 3H).

Step 3-4: Iridium dimer Preparation of complex compound (l)

The title compound was prepared in the same manner, except that compound (i) prepared in step 3-3 was used instead of compound (c) prepared in step 1-3.

Steps 3-5: bis [5- hexyl -8- trifluoromethyl -5H- Benzo(c)(1,5)naphthyridine -6-on] ( tetraphenylimidodiphosphinato )Iridium(III)( Ir3 ) manufacture of

Compound (1) (1 g, 0.54 mmol) prepared in step 3-4 above and potassium tetraphenylimidodiphosphinate (ktpip, 0.617 g, 1.35 mmol) in 2-ethoxyethanol (25 ml) under a nitrogen atmosphere. The solution was stirred at 140° C. for 24 hours. After cooling to room temperature, the reaction mixture was poured into water and extracted with DCM. The extracted organic layer was mixed with Na ₂ SO ₄ After drying to anhydrous and concentrating in vacuo, the obtained residue was purified by silica gel column chromatography using MeOH:EtOAc (20:80%, v/v) as eluent to give the title compound as a yellow solid.

Yield: 40% (0.3 g)

¹ H NMR (300 MHz, CDCl ₃ , δ): 8.83 (d, J = 5.1 Hz, 2H), 8.06 (s, 2H), 7.78 - 7.72 (m, 4H), 7.41 - 7.30 (m, 7H), 7.26 - 7.24 (m, 1H), 7.19 - 7.08 (m, 6H), 7.06 - 6.99 (m, 2H), 6.91 - 6.82 (m, 4H), 6.52 (s, 2H), 4.40 - 4.25 (m, 4H) ), 1.90 - 1.80 (m, 4H), 1.62 - 1.36 (m, 13H), 0.95 (t, J = 6.4 Hz, 5H).

¹³ C NMR (75 MHz, CDCl ₃ , δ): 161.4, 149.5, 148.2, 143.5, 140.4, 139.9, 138.4, 133.2, 130.8, 130.1, 130.6, 130.6, 130.5, 129.9, 1 28.3, 128.1, 127.5, 127.3, 125.7 , 123.2, 122.1, 117.5, 117.4, 43.0, 31.8, 27.1, 26.9, 22.8, 14. 4.

Experimental example One - Ir Complex compound thermal characterization

In order to confirm the thermal properties of the Ir complex compounds Ir1, Ir2 and Ir3 prepared in Preparation Examples 1 to 3, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were performed under a nitrogen atmosphere. And the results are shown in Table 1 below.

Referring to Table 1, the decomposition temperatures (Td, 5% weight loss) of the Ir complex compounds Ir1, Ir2 and Ir3 were 353 °C, 364 °C and 340 °C, respectively, indicating that the Ir complex compounds exhibit excellent thermal stability. Confirmed. In addition, it can be confirmed that the Ir complex compounds have a high glass transition temperature (Tg) and exhibit excellent film morphological stability at room temperature.

Experimental example 2 - Ir complex compound optical physical characterization

In order to confirm the photophysical properties of the Ir complex compounds Ir1, Ir2 and Ir3 prepared in Preparation Examples 1 to 3, the luminescence quantum efficiency (PLQY) and triplet lifetime (τ) were measured, and the results are shown in the table below. 1.

At this time, the luminescence quantum efficiency (PLQY) is the luminescence quantum efficiency (PLQY) in a dichloromethane (DCM) solution at room temperature fac -Ir (ppy) _{3 ,} a material known as a phosphorescent green dopant. (PLQY: 40%) was measured, and the triplet lifetime (τ) was measured in a state where DCM was degassed.

Referring to Table 1, the Ir complex compounds Ir1, Ir2 and Ir3 are all fac -Ir(ppy) ₃ It can be seen that the quantum efficiency is significantly improved compared to the above. Additionally, it can be seen from the above results that the soluble substituent introduced at an appropriate position of the metal complex not only improves solubility, but also increases PLQY compared to known dopant materials having similar molecular structures.

In addition, the Ir3 complex exhibits the smallest triplet lifetime, resulting in triplet-triplet annihilation (TTA), triplet-polaron quenchin (TPQ), and self-annihilation (self-annihilation). -quenching is reduced, so it is expected to exhibit very low efficiency roll-off at high current densities.

Experimental example 3 - Ir Complex compound electrochemical characterization

In order to confirm the electrochemical properties of the Ir complex compounds Ir1, Ir2 and Ir3 prepared in Preparation Examples 1 to 3, cyclic voltammetry (CV) analysis was performed, and oxidation potential (E _ox for Fe / Fe ⁺ ) was measured by the onset peak at 1.38 eV, from which HOMO and LUMO (E _g (optical) + HOMO) values were calculated, and the results are shown in Table 1 below.

Experimental example 4 - Ir Complex compound optical characterization

In order to confirm the optical properties of the Ir complex compounds Ir1, Ir2 and Ir3 prepared in Preparation Examples 1 to 3, UV-Vis absorption spectrum and PL spectrum in dichloromethane (DCM) solution ( ^10-5 M) at room temperature, The PL spectrum in the film state at room temperature and the PL spectrum in the 2-methyltetrahydrofuran (2-MeTHF) matrix state at low temperature (77K) were measured, respectively, and are shown in FIG. 3 .

Specifically, the UV-Vis absorption spectrum and PL spectrum of Ir1 are shown in FIG. 3(a), the UV-Vis absorption spectrum and PL spectrum of Ir2 are shown in FIG. 3(b), and the UV-Vis absorption spectrum and PL spectrum of Ir3 are shown. 3(c), respectively. In addition, the maximum PL (PL _max ) was measured from FIG. 3 and shown in Table 1 below.

3 and Table 1, the compounds Ir1, Ir2, and Ir3 show strong absorption peaks at 334 nm and 345 nm according to the π-π* transition of the cyclometalated ligand and charge transfer between the metal and the ligand ( It can be seen that it shows an absorption peak in the 400 to 460 nm region according to metal-to-ligand charge transfer (MLCT). In addition, it was confirmed that the introduction of a soluble functional group, ethoxyethanol (EO ₂ - ), into the Ir1 complex compound did not affect the optical properties, which is considered to be because the ethoxyethanol is connected to the auxiliary ligand through an ether linkage. Therefore, it can be confirmed that the introduction of such a soluble substituent improves the solubility of the Ir(III) complex compound and enables the preparation of a uniform and flat packed film. In addition, as a result of calculating the optical band gap (E _g ^opt ) of the three Ir (III) complexes as the point at which UV-Vis absorption starts, it is confirmed that all of them emit bright-green light. could In addition, by photoexcitation according to the MLCT absorption gap, the three Ir(III) complexes exhibit large featureless emission spectra and maximum PL (PL _max ), which indicates that the emission of the three Ir(III) complexes This is because this is caused by MLCT or ligand-to-ligand charge transfer (LLCT), not LC ³ π-π*. Additionally, a small PL red shift is observed in the film state, which is thought to be due to the cohesive force and/or strong intermolecular interaction between Ir(III) complexes in the solid film.

In addition, the PL spectrum in the 2-methyltetrahydrofuran (2-MeTHF) matrix state at low temperature (77 K) shows a more structured emission spectrum than that at room temperature. This is because the influence of LC ³ π-π* is large.

In addition, the triplet lifetime (τ) of the host film doped with the three Ir(III) complex compounds has the order of Ir2 > Ir1 > Ir3, which is consistent with the order measured with the undoped film in the solution state. did

T _g
(℃) T _d
(℃) λ _PL ^{1 )}
(nm) λ _PL ^{2 )}
(nm) λ _PL ^{3 )}
(nm) PLQY
(%) τ
(µs) HOMO
(eV) LUMO
(eV) Eg
(eV) Ir1 146 353 514 523 502 80 0.66 -5.7 -3.2 2.5 Ir2 161 364 510 515 501 75 0.75 -5.7 -3.2 2.5 Ir3 112 340 530 536 516 47 0.44 -5.6 -3.3 2.3

1) CH ₂ Cl ₂ / RT, 2) neat film/ RT, 3) 2-MeTHF/ 77K

Example 1 (device A)

After spin-coating poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) on a glass substrate coated with UV-ozone-treated ITO (indium tin oxide), annealing in air at 150°C for 15 minutes Thus, a hole injection layer (HIL) having a thickness of 40 nm was formed.

Subsequently, a coating composition containing the following compound CBP as a host and the iridium complex compound Ir1 (doped at 15% by weight) synthesized in Preparation Example 1 as a phosphorescent dopant was spin-coated on the hole injection layer under a nitrogen atmosphere, and then at 100 ° C. Annealing was performed for 30 minutes to form a light emitting layer (EML) having a thickness of 30 nm.

[CBP]

1,3,5-tris(N-phenyl-benzimidazol-2-yl)benzene (TPBi) was deposited on the light emitting layer to form an electron transport layer (ETL) having a thickness of 40 nm, and lithium fluoride was formed on the electron transport layer. (LiF) was deposited to form an electron injection layer having a thickness of 1 nm, and aluminum was deposited on the electron injection layer to form a cathode having a thickness of 120 ^nm . A light emitting device was fabricated.

[TPBi]

Example 2 (device B)

An organic light emitting device was manufactured in the same manner as in Example 1, except that the iridium complex compound Ir2 synthesized in Preparation Example 2 was used instead of the iridium complex compound Ir1 as a phosphorescent dopant.

Example 3 (device C)

An organic light emitting device was manufactured in the same manner as in Example 1, except that the iridium complex compound Ir3 synthesized in Preparation Example 3 was used instead of the iridium complex compound Ir1 as a phosphorescent dopant.

Example 4 (device D)

Example, except that a 50 nm light emitting layer was formed using 4',4''-tris (N-carbazolyl)triphenylamine (TCTA) and TPBi in a weight ratio of 1 to 1 instead of CBP as a host. An organic light emitting diode was manufactured using the same method as in 1.

[TCTA]

Example 5 (element E)

Instead of CBP as a host, 4',4''-tris (N-carbazolyl) triphenylamine (TCTA) and TPBi were used in a weight ratio of 1 to 1, and as a phosphorescent dopant, instead of the iridium complex compound Ir1, Preparation Example 2 An organic light emitting device was manufactured in the same manner as in Example 1, except that the iridium complex compound Ir2 synthesized in was used.

Example 6 (device F)

Instead of CBP as a host, 4',4''-tris (N-carbazolyl) triphenylamine (TCTA) and TPBi were used in a weight ratio of 1 to 1, and as a phosphorescent dopant, instead of the iridium complex compound Ir1, Preparation Example 3 An organic light emitting device was manufactured in the same manner as in Example 1, except that the iridium complex compound Ir3 (doped at 12% by weight) synthesized in was used.

Example 7 (element G)

An 8 nm thick 4,4′-cyclohexylidenebis[N,N-bis(4-methylphenyl)benzenamide] (TAPC) interface is formed between the hole injection layer and the light emitting layer, and a 50 nm TPBi electron transport layer was formed, except that a 60 nm light emitting layer was formed using 4',4''-tris(N-carbazolyl)triphenylamine (TCTA) and TPBi in a weight ratio of 1:1 instead of CBP as a host. An organic light emitting device was manufactured using the same method as in Example 1.

[TAPC]

Experimental example 5- organic light emitting device film uniformity evaluation

In order to evaluate the film uniformity of the film formed by the solution process of the organic light emitting device prepared in the above example, after spin-coating the Ir complex compounds Ir1, Ir2 and Ir3 on the CBP film, an atomic force microscope (AFM) image was confirmed. And the results are shown in Figure 4.

Referring to FIG. 4, the surface roughness values of the films to which Ir1, Ir2, and Ir3 were applied were 0.64 nm, 0.69 nm, and 0.71 nm, respectively, confirming that all films were formed uniformly and flatly.

Experimental example 6- Evaluation of light emitting characteristics of organic light emitting devices

Operation voltage (OV), external quantum efficiency (EQE), current efficiency (CE), photoluminescence, of the organic light emitting devices A to G prepared in Examples 1 to 7 PE), color coordinates (x, y), maximum electroluminescent (EL _max ), and maximum luminance (Maximum Luminance) were measured, respectively.

Specifically, the current density-voltage-luminance (J-V-L) characteristics of the organic light emitting devices A, B, and C are shown in FIG. 5 (a), and current efficiency and photoluminescence characteristics according to current density are shown in FIG. The external quantum efficiency according to FIG. 5(c) and the electroluminescence according to the wavelength are shown in FIG. 5(d), respectively.

In addition, current density-voltage-luminance (J-V-L) characteristics of the organic light emitting devices D, E, and F are shown in FIG. 6 (a), and current efficiency and photoluminescence characteristics according to current density are shown in FIG. The external quantum efficiency according to FIG. 6 (c) is respectively shown.

In addition, the current density-voltage-luminance (J-V-L) characteristics of the organic light emitting device G are shown in FIG. 6(a), the current efficiency and photoluminescence characteristics according to current density are shown in FIG. 6(b), and the external quantum efficiency according to luminance is shown in FIG. 6(c) and electroluminescence according to wavelength are shown in FIG. 6(d).

At this time, the driving voltage (OV) at luminance of 1 cd/m ² and 10,000 cd/m ² from FIGS. 4 to 6; Measured values at maximum external quantum efficiency (EQE) and luminance of 10,000 cd/m ² ; Current efficiency (CE) maximum value and measured value at current density 30 mA/cm ² ; photoluminescence (PE) maxima and measured values at a current density of 30 mA/cm ² ; Color coordinates (x,y) at a current density of 30 mA/cm ² ; And the maximum electroluminescent (EL _max ) at a current density of 30 mA/cm ² was measured and shown in Tables 2 and 3 below.

host dopant OV ¹⁾
(V) OV ²⁾
(V) EQE ^{3 )}
(%) EQE ^{4 )}
(%) CE ⁵⁾
(cd/A) CE6 ⁾
(cd/A) Example 1(A) CBP Ir1 5.6 7.3 18.51 11.47 70.18 39.52 Example 2
(B) CBP Ir2 5.7 8.2 17.20 15.50 61.22 47.40 Example 3(C) CBP Ir3 5.7 8.7 7.19 7.07 26.31 26.20 Example 4(D) TCTA+
TPBi Ir1 5.3 8.5 24.22 22.91 92.44 60.53 Example 5(E) TCTA+
TPBi Ir2 5.0 7.6 23.53 16.71 84.25 49.56 Example 6(F) TCTA
TPBi Ir3 5.4 8.7 13.58 13.27 46.22 44.24 Example 7 (G) TCTA+
TPBi Ir3 5.1 8.3 19.40 19.29 85.31 81.91

1) @1 cd/m ² , 2) @10,000 cd/m ² , 3) Maximum, 4) @10,000 cd/m ² , 5) Maximum, 6) @30 mA/cm ²

host dopant PE ⁷⁾
(lm/W) PE8 ⁾
(lm/W) CIEx CIEy EL _max
(nm) maximum luminance
(cd/m ² ) Example 1(A) CBP Ir1 22.88 13.94 0.335 0.615 521 22083 Example 2
(B) CBP Ir2 17.49 12.34 0.340 0.612 522 34729 Example 3(C) CBP Ir3 6.75 6.49 0.380 0.587 534 16993 Example 4(D) TCTA+
TPBi Ir1 26.43 17.98 0.331 0.617 520 42249 Example 5(E) TCTA+
TPBi Ir2 33.08 15.01 0.340 0.612 522 35292 Example 6(F) TCTA+
TPBi Ir3 13.19 11.47 0.382 0.587 534 29745 Example 7 (G) TCTA+
TPBi Ir3 20.30 17.72 0.383 0.596 534 54914

7) Maximum, 8) @30 mA/cm ²

Referring to Tables 2 and 3, the organic light-emitting devices of Examples 1 and 4 employing an iridium complex compound as a dopant in which a picolinic acid derivative into which an appropriate soluble group is introduced as an auxiliary ligand have excellent external quantum efficiency and current efficiency. It can be seen that this high In addition, the organic light-emitting devices of Examples 3, 6, and 7 employing the tetraphenyl imidodiphosphinate derivative as an auxiliary ligand had a difference between the maximum value of the external quantum efficiency (EQE) and the measured value at 10,000 cd/m ² luminance. Since it is very small, it can be seen that the efficiency roll-off phenomenon, in which the efficiency rapidly decreases at high current density, is prevented.

1: substrate 2: anode
3: light emitting layer 4: cathode
5: hole injection layer 6: hole transport layer
7: light emitting layer 8: electron transport layer

Claims (11)

An iridium complex compound represented by Formula 1 below:
[Formula 1]

In Formula 1,
R ₁ is C _1-60 alkyl unsubstituted or substituted with one or more substituents selected from the group consisting of deuterium, halogen and alkyl;
R ₂ is C _1-10 haloalkyl unsubstituted or substituted with deuterium;

Is any one selected from the group consisting of Formulas 2a to 2c,
[Formula 2a]

[Formula 2b]

[Formula 2c]

In Formulas 2a to 2c,
R ₁₁ and R ₁₂ are each independently C _1-10 alkoxy unsubstituted or substituted with alkoxy;
R ₁₃ to R ₁₆ are each independently hydrogen or deuterium;
a1 and a2 are 1;
a3 to a6 are each independently an integer of 0 to 2;
* is a linking site with Ir.
According to claim 1,
R ₁ is unsubstituted; or C _1-10 alkyl substituted with methyl or ethyl;
R ₂ is an unsubstituted C _1-10 haloalkyl;
Iridium complex.
According to claim 1,
R ₁ is methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, sec-butyl, pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, 1-methylhexyl, 2-methylhexyl, 3 -methylhexyl, 4-methylhexyl, 5-methylhexyl, 1-ethylhexyl, 2-ethylhexyl, 3-ethylhexyl, 4-ethylhexyl, or heptyl;
R ₂ is trifluoromethyl, trichloromethyl, or tribromomethyl;
Iridium complex.
According to claim 1,
R ₁₁ and R ₁₂ are each independently CH ₃ (CH ₂ ) _n O-, or CH ₃ (CH ₂ ) _n O(CH ₂ ) _m O-;
Here, n is each independently an integer from 0 to 5, m is an integer from 1 to 5,
R ₁₃ to R ₁₆ are hydrogen;
Iridium complex.
According to claim 1,

Is any one selected from the group consisting of Formulas 3a to 3d,
Iridium complexes:
[Formula 3a]

[Formula 3b]

[Formula 3c]

[Formula 3d]

In Formulas 3a to 3d,
Description of R ₁₁ to R ₁₆ is as defined in claim 1,
* is a linking site with Ir.
According to claim 1,
The iridium complex compound is represented by any one of the following formulas 4a to 4d,
Iridium complexes:
[Formula 4a]

[Formula 4b]

[Formula 4c]

[Formula 4d]

In Formulas 4a to 4d,
Descriptions of R ₁ , R ₂ and R ₁₁ to R ₁₆ are as defined in claim 1.
According to claim 1,
The complex compound is any one selected from the group consisting of the following compounds,
Iridium complexes:

.
An iridium complex represented by Formula 4a:
[Formula 4a]

In Formula 4a,
R ₁ is 1-methylhexyl, 2-methylhexyl, 3-methylhexyl, 4-methylhexyl, 5-methylhexyl, 1-ethylhexyl, 2-ethylhexyl, 3-ethylhexyl, or 4-ethylhexyl;
R ₂ is C _1-10 haloalkyl unsubstituted or substituted with deuterium;
R ₁₁ is hydrogen or deuterium.
According to claim 8,
The complex compound is the following compound,
Iridium complexes:

.
a first electrode; a second electrode provided to face the first electrode; and one or more organic material layers provided between the first electrode and the second electrode, wherein at least one of the organic material layers contains the iridium complex compound according to any one of claims 1 to 9. which includes,
organic light emitting device.
According to claim 10,
The organic layer includes a light emitting layer, and the iridium complex compound is included as a dopant of the light emitting layer.
organic light emitting device.

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