JP2015083560A - Organometallic complex, light emitting element, light emission device, electronic apparatus, and illumination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organometallic complex which can convert a triplet excited state to light emission.SOLUTION: The present invention provides an organometallic complex having a structure represented by general formula (G7) where Ris a branched alkyl group having carbon atoms of 4 or more with straight chain carbon atoms of 3 or more, or an alkyl group having carbon atoms of 5-10, Ris hydrogen, an alkyl group having carbon atoms of 1-6, or a phenyl group, Ris hydrogen or an alkyl group having carbon atoms of 1-6, R-Rare independently hydrogen, an alkyl group having carbon atoms of 1-6, an alkoxy group having carbon atoms of 1-6, an alkylthio group having carbon atoms of 1-6, a halogen group, a haloalkyl group having carbon atoms of 1-6, or an aryl group having carbon atoms of 1-6, M is central metal and represents a group 9 element or a group 10 element.

Description

The present invention relates to an object, a method, or a manufacturing method. Or this invention relates to a process, a machine, a manufacture, or a composition (composition of matter). In particular, one embodiment of the present invention relates to a semiconductor device, a display device, a light-emitting device, a lighting device, a driving method thereof, or a manufacturing method thereof. In particular, one embodiment of the present invention relates to an organometallic complex. In particular, the present invention relates to an organometallic complex that can convert a triplet excited state into light emission. In addition, the present invention relates to a light-emitting element, a light-emitting device, an electronic device, and a lighting device using the organometallic complex.

In recent years, a light-emitting element using a light-emitting organic compound or an inorganic compound as a light-emitting material has been actively developed. In particular, the structure of a light-emitting element called an EL (Electroluminescence) element is a simple structure in which a light-emitting layer containing a light-emitting material is provided between electrodes. Due to the characteristics such as voltage drive, it is attracting attention as a next-generation flat panel display element. In addition, a display using such a light-emitting element is characterized by excellent contrast and image quality and a wide viewing angle. Furthermore, since these light emitting elements are surface light sources, their application as light sources for backlights and illumination of liquid crystal displays is also considered.

In the case where the light-emitting substance is a light-emitting organic compound, the light-emitting mechanism of the light-emitting element is a carrier injection type. That is, by applying a voltage with the light emitting layer sandwiched between the electrodes, electrons and holes injected from the electrodes are recombined and the light emitting material becomes excited, and emits light when the excited state returns to the ground state. And as a kind of excited state, a singlet excited state (S ^* ) and a triplet excited state (T ^* ) are possible. Further, the statistical generation ratio of the light emitting element is considered to be S ^* : T ^* = 1: 3.

A light-emitting organic compound usually has a ground state in a singlet state. Therefore, light emission from the singlet excited state (S ^* ) is called fluorescence because it is an electronic transition between the same multiplicity. On the other hand, light emission from the triplet excited state (T ^* ) is called phosphorescence because it is an electronic transition between different multiplicity. Here, in a compound emitting fluorescence (hereinafter referred to as a fluorescent compound), phosphorescence is usually not observed at room temperature, and only fluorescence is observed. Therefore, the theoretical limit of the internal quantum efficiency (ratio of photons generated with respect to injected carriers) in a light emitting device using a fluorescent compound is 25% on the basis that S ^* : T ^* = 1: 3. It is said that.

On the other hand, if a phosphorescent compound is used, the internal quantum efficiency is theoretically possible up to 100%. That is, the luminous efficiency can be four times that of the fluorescent compound. For these reasons, in order to realize a highly efficient light-emitting element, development of a light-emitting element using a phosphorescent compound has been actively performed in recent years. In particular, as phosphorescent compounds, organometallic complexes having iridium or the like as a central metal have attracted attention because of their high phosphorescent quantum yield. For example, Patent Documents 1 and 2 disclose iridium as a central metal. Organometallic complexes are disclosed as phosphorescent materials.

An advantage of using a highly efficient light-emitting element is that power consumption of an electronic device using the light-emitting element can be reduced. In recent years when energy issues have been addressed, power consumption is becoming a very important factor because it is becoming a major factor affecting consumers' purchasing trends.

International Publication No. 00/70655 JP2013-53158A

An object of one embodiment of the present invention is to provide a novel substance that can emit phosphorescence. Another object is to provide a novel substance with high emission efficiency. Another object is to provide a new substance. Another object is to provide a light-emitting element, a light-emitting device, an electronic device, or a lighting device using the novel substance.

Another object is to provide a light-emitting element, a light-emitting device, an electronic device, or a lighting device with high emission efficiency. Another object is to provide a highly reliable light-emitting element, light-emitting device, electronic device, or lighting device. Another object is to provide a light-emitting element, a light-emitting device, an electronic device, or a lighting device with low power consumption. Another object is to provide a novel light-emitting element, light-emitting device, electronic device, or lighting device.

Note that the description of these problems does not disturb the existence of other problems. Note that one embodiment of the present invention does not have to solve all of these problems. Issues other than these will be apparent from the description of the specification, drawings, claims, etc., and other issues can be extracted from the descriptions of the specification, drawings, claims, etc. It is.

One embodiment of the disclosed invention is an organometallic complex having a structure represented by General Formula (G1).

However, in General Formula (G1), R ¹¹ represents a substituted or unsubstituted branched alkyl group having 4 or more carbon atoms and a straight chain carbon number of 3 or more, and R ² is hydrogen, substituted Or an unsubstituted alkyl group having 1 to 6 carbon atoms or a substituted or unsubstituted phenyl group, R ³ represents hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, and R ⁴ to R ⁷ is independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. Represents a group, a halogen group, a substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms.

Another embodiment of the present invention is an organometallic complex having a structure represented by General Formula (G2).

However, in General Formula (G2), R ¹² represents a substituted or unsubstituted alkyl group having 5 to 10 carbon atoms, and R ² is hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or Represents a substituted or unsubstituted phenyl group, R ³ represents hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, and R ^{4 to} R ⁷ independently represent hydrogen, substituted or unsubstituted. An alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted alkylthio group having 1 to 6 carbon atoms, a halogen group, a substituted or unsubstituted carbon atom having 1 to A haloalkyl group having 6 or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms;

Another embodiment of the present invention is an organometallic complex represented by General Formula (G3).

However, in General Formula (G3), L represents a monoanionic ligand. R ¹¹ represents a substituted or unsubstituted branched alkyl group having 4 or more carbon atoms and a straight chain carbon number of 3 or more, and R ² is hydrogen, substituted or unsubstituted carbon atoms having 1 to 6 carbon atoms. R ³ represents a hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, and R ^{4 to} R ⁷ are each independently hydrogen. Substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, substituted or unsubstituted alkylthio group having 1 to 6 carbon atoms, halogen group, substituted or unsubstituted Represents a haloalkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms.

Another embodiment of the present invention is an organometallic complex represented by General Formula (G4).

However, in General Formula (G4), L represents a monoanionic ligand. R ¹² represents a substituted or unsubstituted alkyl group having 5 to 10 carbon atoms, and R ² represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted phenyl group. , R ³ represents hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, and R ^{4 to} R ⁷ each independently represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. Substituted or unsubstituted alkoxy groups having 1 to 6 carbon atoms, substituted or unsubstituted alkylthio groups having 1 to 6 carbon atoms, halogen groups, substituted or unsubstituted haloalkyl groups having 1 to 6 carbon atoms, or substituted or unsubstituted A substituted aryl group having 6 to 10 carbon atoms is represented.

In the organometallic complexes represented by the general formulas (G3) to (G4), the monoanionic ligand includes a monoanionic bidentate chelate ligand having a beta diketone structure and a monoanionic property having a carboxyl group. And a monoanionic bidentate ligand having a phenolic hydroxyl group, or a monoanionic bidentate chelate ligand in which two coordination elements are both nitrogen.

The monoanionic ligand is preferably any one of the general formulas (L1) to (L7).

However, in the general formulas (L1) to (L7), R ^{71 to} R ¹⁰⁹ are each independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a halogen group, a vinyl group, substituted or unsubstituted. Represents a haloalkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, or a substituted or unsubstituted alkylthio group having 1 to 6 carbon atoms. A ^{1 to} A ³ each independently represent nitrogen, sp ² hybrid carbon bonded to hydrogen, or sp ² carbon bonded to a substituent R, wherein the substituent R is an alkyl group having 1 to 6 carbon atoms. , A halogen group, a haloalkyl group having 1 to 6 carbon atoms, or a phenyl group.

Another embodiment of the present invention is an organometallic complex represented by General Formula (G5).

However, in General Formula (G5), R ¹¹ represents a substituted or unsubstituted branched alkyl group having 4 or more carbon atoms and a straight chain carbon number of 3 or more, and R ² is hydrogen, substituted Or an unsubstituted alkyl group having 1 to 6 carbon atoms or a substituted or unsubstituted phenyl group, R ³ represents hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, and R ⁴ to R ⁷ is independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. Represents a group, a halogen group, a substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms.

Another embodiment of the present invention is an organometallic complex represented by General Formula (G6).

However, in General Formula (G6), R ¹² represents a substituted or unsubstituted alkyl group having 5 to 10 carbon atoms, and R ² is hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or Represents a substituted or unsubstituted phenyl group, R ³ represents hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, and R ^{4 to} R ⁷ independently represent hydrogen, substituted or unsubstituted. An alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted alkylthio group having 1 to 6 carbon atoms, a halogen group, a substituted or unsubstituted carbon atom having 1 to A haloalkyl group having 6 or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms;

Another embodiment of the present invention is an organometallic complex represented by Structural Formula (100).

Another embodiment of the present invention is an organometallic complex represented by Structural Formula (101).

Another embodiment of the present invention is an organometallic complex represented by the structural formula (102).

Another embodiment of the present invention is an organometallic complex represented by Structural Formula (111).

Another embodiment of the present invention is an organometallic complex represented by Structural Formula (112).

Another embodiment of the present invention is a light-emitting element having an organometallic complex in a light-emitting layer, in which the organometallic complex has a bond with iridium on a nitrogen atom at the 3-position of the pyrimidine skeleton, and the 4-position of the pyrimidine skeleton. The carbon atom has a bond with a benzene ring, the benzene ring has a bond with the iridium, the 6-position carbon atom of the pyrimidine skeleton has a bond with the first substituent, and the first substituent Is a light-emitting element which is a branched alkyl group having 4 or more substituted or unsubstituted carbon atoms and 3 or more linear carbon atoms.

Another embodiment of the present invention is a light-emitting element having an organometallic complex in a light-emitting layer, in which the organometallic complex has a bond with iridium on a nitrogen atom at the 3-position of the pyrimidine skeleton, and the 4-position of the pyrimidine skeleton. The carbon atom has a bond with a benzene ring, the benzene ring has a bond with the iridium, the 6-position carbon atom of the pyrimidine skeleton has a bond with the first substituent, and the first substituent Is a light-emitting element which is a substituted or unsubstituted alkyl group having 5 to 10 carbon atoms.

Another embodiment of the present invention is a light-emitting element including the above organometallic complex between a pair of electrodes. In particular, the organometallic complex is preferably included in the light emitting layer.

A light-emitting device, an electronic device, and a lighting device each using the light-emitting element are also included in the category of one embodiment of the present invention. Note that the light emitting device in this specification includes an image display device and a light source. In addition, a connector such as a FPC (Flexible Printed Circuit) or TCP (Tape Carrier Package) attached to a panel, a module provided with a printed wiring board at the end of TCP, or a COG (Chip On Glass) method on a light emitting element The module on which the IC (integrated circuit) is directly mounted may include a light emitting device.

The organometallic complex according to one embodiment of the present invention includes a branched alkyl group having 4 or more carbon atoms and 3 or more straight carbon atoms in a substituent bonded to the 6-position carbon atom of the pyrimidine skeleton, Or it has a C5-C10 alkyl group. In the organometallic complex according to one embodiment of the present invention, the number of carbons in the main chain of the substituent is large, and thus a portion where π electrons are not conjugated is relatively large. Due to the three-dimensional effect, the layer containing the organometallic complex according to one embodiment of the present invention has a tendency that carriers do not easily flow and are difficult to escape. Therefore, the light-emitting element including the organometallic complex according to one embodiment of the present invention has high external quantum efficiency due to the carrier balance.

For example, when the alkyl group bonded to the 6-position carbon atom of the pyrimidine skeleton has 4 carbon atoms, the tert-butyl group has 2 linear carbon atoms when compared with the tert-butyl group and the isobutyl group. On the other hand, the isobutyl group has 3 linear carbon atoms. As a result, the isobutyl group has a relatively large portion where π electrons are not conjugated. Then, since it becomes difficult for carriers to escape from the layer containing the organometallic complex, the carrier balance of the light-emitting element is adjusted. Therefore, a light-emitting element using an organometallic complex whose substituent is an isobutyl group has higher external quantum efficiency than a light-emitting element using an organometallic complex whose substituent is a tert-butyl group.

A light-emitting element having an organometallic complex in which such a substituent is bonded to a pyrimidine skeleton tends to increase the external quantum efficiency by about 10 to 20%.

According to one embodiment of the present invention, a novel substance that can emit phosphorescence can be provided. Alternatively, a novel substance with high emission efficiency can be provided. Alternatively, a light-emitting element, a light-emitting device, an electronic device, or a lighting device using the novel substance can be provided.

Alternatively, a light-emitting element, a light-emitting device, an electronic device, or a lighting device with high emission efficiency can be provided. Alternatively, a highly reliable light-emitting element, light-emitting device, electronic device, or lighting device can be provided. Alternatively, a light-emitting element, a light-emitting device, an electronic device, or a lighting device with low power consumption can be provided. Alternatively, a novel substance can be provided. Alternatively, a novel light-emitting element, light-emitting device, electronic device, or lighting device can be provided. Note that the description of these effects does not disturb the existence of other effects. Note that one embodiment of the present invention does not necessarily have all of these effects. It should be noted that the effects other than these are naturally obvious from the description of the specification, drawings, claims, etc., and it is possible to extract the other effects from the descriptions of the specification, drawings, claims, etc. It is.

6A and 6B illustrate a light-emitting element of one embodiment of the present invention. FIG. 9 illustrates a passive matrix light-emitting device. FIG. 9 illustrates a passive matrix light-emitting device. FIG. 10 illustrates an active matrix light-emitting device. 6A and 6B illustrate electronic devices. The figure explaining an illuminating device. The figure explaining an illuminating device. ¹ H NMR chart of an organometallic complex represented by Structural Formula (100). The ultraviolet-visible absorption spectrum and emission spectrum of the organometallic complex represented by Structural Formula (100). LC / MS spectrum of the organometallic complex represented by Structural Formula (100). ¹ H NMR chart of an organometallic complex represented by Structural Formula (101). The ultraviolet-visible absorption spectrum and emission spectrum of the organometallic complex represented by Structural Formula (101). LC / MS spectrum of the organometallic complex represented by Structural Formula (101). ¹ H NMR chart of an organometallic complex represented by Structural Formula (102). The ultraviolet-visible absorption spectrum and emission spectrum of the organometallic complex represented by Structural Formula (102). ¹ H NMR chart of an organometallic complex represented by Structural Formula (111). The ultraviolet-visible absorption spectrum and emission spectrum of the organometallic complex represented by Structural Formula (111). ¹ H NMR chart of an organometallic complex represented by Structural Formula (112). The ultraviolet-visible absorption spectrum and emission spectrum of the organometallic complex represented by Structural Formula (112). LC / MS spectrum of the organometallic complex represented by Structural Formula (112). 6A and 6B illustrate a light-emitting element of an example. FIG. 6 shows voltage-current characteristics of the light-emitting element 1. FIG. 6 shows voltage-luminance characteristics of the light-emitting element 1. FIG. 11 shows luminance-current efficiency characteristics of the light-emitting element 1. FIG. 11 shows luminance vs. external quantum efficiency characteristics of the light-emitting element 1. FIG. 9 shows an emission spectrum of the light-emitting element 1. FIG. 11 shows results of reliability tests of the light-emitting element 1. FIG. 11 shows voltage-current characteristics of the light-emitting element 2; FIG. 11 shows voltage-luminance characteristics of the light-emitting element 2; FIG. 14 shows luminance-current efficiency characteristics of the light-emitting element 2; FIG. 14 shows luminance vs. external quantum efficiency characteristics of the light-emitting element 2. FIG. 9 shows an emission spectrum of the light-emitting element 2; FIG. 11 shows voltage-current characteristics of the light-emitting element 3; FIG. 10 shows voltage-luminance characteristics of the light-emitting element 3; FIG. 11 shows luminance-current efficiency characteristics of the light-emitting element 3; FIG. 14 shows luminance vs. external quantum efficiency characteristics of the light-emitting element 3. FIG. 6 shows an emission spectrum of the light-emitting element 3. FIG. 11 shows voltage-current characteristics of the light-emitting element 4; FIG. 11 shows voltage-luminance characteristics of the light-emitting element 4; FIG. 11 shows luminance-current efficiency characteristics of the light-emitting element 4; FIG. 11 shows luminance vs. external quantum efficiency characteristics of the light-emitting element 4. FIG. 6 shows an emission spectrum of the light-emitting element 4. FIG. 9 shows results of reliability tests of the light-emitting element 4; FIG. 11 shows voltage-current characteristics of the light-emitting element 5; FIG. 11 shows voltage-luminance characteristics of the light-emitting element 5; FIG. 11 shows luminance-current efficiency characteristics of the light-emitting element 5; FIG. 14 shows luminance vs. external quantum efficiency characteristics of the light-emitting element 5. FIG. 9 shows an emission spectrum of the light-emitting element 5.

Embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it is easily understood by those skilled in the art that modes and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments below. Note that in structures of the invention described below, the same portions or portions having similar functions are denoted by the same reference numerals in different drawings, and description thereof is not repeated.

(Embodiment 1)
In this embodiment, an organometallic complex of one embodiment of the present invention is described.

One embodiment of the present invention coordinates a 4-phenylpyrimidine derivative having an alkyl group at the 6-position (sometimes named as a 6-phenylpyrimidine derivative having an alkyl group at the 4-position depending on the type of the substituent). It is an organometallic complex having a group 9 element or a group 10 element as a central metal.

Specifically, one embodiment of the present invention is an organometallic complex having a structure represented by General Formula (G7).

In General Formula (G7), R ¹ represents a substituted or unsubstituted branched alkyl group having 4 or more carbon atoms and a straight chain carbon number of 3 or more, or a substituted or unsubstituted carbon atom having 5 to 5 carbon atoms. Represents 10 alkyl groups. R ² represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted phenyl group, and R ³ represents hydrogen, or substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. Each of R ^{4 to} R ⁷ is independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted group; An alkylthio group having 1 to 6 carbon atoms, a halogen group, a substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms is represented. M is a central metal and represents a Group 9 element or a Group 10 element.

R ¹ is a substituted or unsubstituted branched alkyl group having 4 or more carbon atoms and a straight chain carbon number of 3 or more, or a substituted or unsubstituted alkyl group having 5 to 10 carbon atoms. Such alkyl groups suppress intermolecular interactions due to steric hindrance. Therefore, a side reaction in the synthesis reaction of the organometallic complex which is one embodiment of the present invention is suppressed, and the yield is improved.

In view of this, as the alkyl group in R ¹ , an isobutyl group, a sec-butyl group, a pentyl group with or without a branch, a hexyl group with or without a branch, a branch with or without a branch Non-heptyl groups, octyl groups with or without branching, nonyl groups with or without branching, decyl groups with or without branching.

Specific examples of the alkyl group having 1 to 6 carbon atoms in R ^{2 to} R ³ are methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group, tert-butyl. Group, n-pentyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylpropyl group, 1,1-dimethylpropyl group, 1,2-dimethylpropyl group, 2,2-dimethylpropyl group And a hexyl group having or not having a branch.

Specific examples of R ^{4 to} R ⁷ are each independently hydrogen, methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, isobutyl group, tert-butyl group, methoxy group, Ethoxy group, propoxy group, isopropoxy group, butoxy group, sec-butoxy group, isobutoxy group, tert-butoxy group, methylsulfinyl group, ethylsulfinyl group, propylsulfinyl group, isopropylsulfinyl group, butylsulfinyl group, isobutylsulfinyl group, sec-butylsulfinyl group, tert-butylsulfinyl group, fluoro group, fluoromethyl group, difluoromethyl group, trifluoromethyl group, chloromethyl group, dichloromethyl group, trichloromethyl group, bromomethyl group, 2,2,2-tri Fluoro A phenyl group substituted with one or more of a til group, a 3,3,3-trifluoropropyl group, a 1,1,1,3,3,3-hexafluoroisopropyl group, a phenyl group, and an alkyl group having 1 to 4 carbon atoms. A phenyl group substituted with one or more alkoxy groups having 1 to 4 carbon atoms, a phenyl group substituted with one or more alkylthio groups having 1 to 4 carbon atoms, or a phenyl group substituted with one or more aryl groups having 6 to 10 carbon atoms Group, a phenyl group substituted one or more with a halogen group, a phenyl group substituted one or more with a haloalkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted naphthalene-yl group, and the like.

Specific examples of M include cobalt, rhodium, iridium, nickel, palladium, and platinum.

Another embodiment of the present invention is an organometallic complex having a structure represented by General Formula (G1). The organometallic complex having the structure represented by the general formula (G1) has a structure in which R ¹ is substituted or unsubstituted and has 4 or more carbon atoms in the organometallic complex having the structure represented by the general formula (G7). A branched alkyl group having 3 or more carbon atoms in the chain is used, and M is iridium (Ir). Therefore, the organometallic complex having a structure represented by General Formula (G1) is also an organometallic complex having a structure represented by General Formula (G7).

In General Formula (G1), R ¹¹ represents a substituted or unsubstituted branched alkyl group having 4 or more carbon atoms and a straight chain carbon number of 3 or more. R ² represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted phenyl group, and R ³ represents hydrogen, or substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. Each of R ^{4 to} R ⁷ is independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted group; An alkylthio group having 1 to 6 carbon atoms, a halogen group, a substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms is represented.

Examples of the alkyl group in R ¹¹ include an isobutyl group, a sec-butyl group, a branched pentyl group, a branched hexyl group, a branched heptyl group, a branched octyl group, and a branched nonyl group. And a decyl group having a branch.

Note that specific examples of R ^{2 to} R ⁷ are the same as those in the general formula (G7).

Another embodiment of the present invention is an organometallic complex having a structure represented by General Formula (G2). Organometallic complex having the structure represented by the general formula (G2), the organometallic complex having the structure represented by the general formula (G7), the R ^1, a substituted or unsubstituted alkyl having 5 to 10 carbon atoms And M is iridium (Ir). Therefore, the organometallic complex having a structure represented by General Formula (G2) is also an organometallic complex having a structure represented by General Formula (G7).

In General Formula (G2), R ¹² represents a substituted or unsubstituted alkyl group having 5 to 10 carbon atoms. R ² represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted phenyl group, and R ³ represents hydrogen, or substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. Each of R ^{4 to} R ⁷ is independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted group; An alkylthio group having 1 to 6 carbon atoms, a halogen group, a substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms is represented.

Examples of the alkyl group for R ¹² include a pentyl group with or without a branch, a hexyl group with or without a branch, a heptyl group with or without a branch, and an octyl with or without a branch. Groups, nonyl groups with or without branching, decyl groups with or without branching.

Note that specific examples of R ^{2 to} R ⁷ are the same as those in the general formula (G7).

Another embodiment of the present invention is an organometallic complex represented by General Formula (G8). The organometallic complex represented by General Formula (G8) is an organometallic complex having a structure represented by General Formula (G7).

In General Formula (G8), R ¹ represents a substituted or unsubstituted branched alkyl group having 4 or more carbon atoms and a straight chain carbon number of 3 or more, or a substituted or unsubstituted carbon atom having 5 to 5 carbon atoms. Represents 10 alkyl groups. R ² represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted phenyl group, and R ³ represents hydrogen, or substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. Each of R ^{4 to} R ⁷ is independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted group; An alkylthio group having 1 to 6 carbon atoms, a halogen group, a substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms is represented. M is a central metal and represents a Group 9 element or a Group 10 element, and L represents a monoanionic ligand.

Note that specific examples of R ^{1 to} R ⁷ and M are the same as those in the general formula (G7).

In the organometallic complex represented by the general formula (G8), the monoanionic ligand includes a monoanionic bidentate chelate ligand having a beta diketone structure and a monoanionic bidentate chelate coordination having a carboxyl group A monoanionic bidentate chelate ligand having a phenolic hydroxyl group, or a monoanionic bidentate chelate ligand in which both two coordination elements are nitrogen is preferable. In particular, it is preferably a monoanionic bidentate chelate ligand having a beta diketone structure. A beta diketone structure is preferable because the solubility of the organometallic complex in an organic solvent is increased, and purification is facilitated. Further, it is preferable to have a beta diketone structure because an organometallic complex having high luminous efficiency can be obtained. Moreover, sublimation property increases by having a beta diketone structure, and there exists an advantage that it is excellent in vapor deposition performance.

In the organometallic complex represented by the general formula (G8), the monoanionic ligand is preferably any one of the general formulas (L1) to (L7).

In the general formulas (L1) to (L7), R71 to R109 are each independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, a halogen group, a vinyl group, a substituted or unsubstituted carbon number of 1 to 4 haloalkyl groups, substituted or unsubstituted alkoxy groups having 1 to 4 carbon atoms, or substituted or unsubstituted alkylthio groups having 1 to 4 carbon atoms. A ^{1 to} A ³ each independently represent nitrogen, sp ² hybrid carbon bonded to hydrogen, or sp ² carbon bonded to a substituent R, wherein the substituent R is an alkyl group having 1 to 4 carbon atoms, A halogen group, a C1-C4 haloalkyl group, or a phenyl group is represented.

Another embodiment of the present invention is an organometallic complex represented by General Formula (G3). In the organometallic complex represented by the general formula (G3), in the organometallic complex represented by the general formula (G8), R ¹ is substituted or unsubstituted and has 4 or more carbon atoms, and 3 linear carbon atoms. The branched alkyl group as described above is used, and M is iridium (Ir). Therefore, the organometallic complex having the structure represented by the general formula (G3) is also represented by the general formula (G8).

In General Formula (G3), R ¹¹ represents a substituted or unsubstituted branched alkyl group having 4 or more carbon atoms and a straight chain carbon number of 3 or more. R ² represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted phenyl group, and R ³ represents hydrogen, or substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. Each of R ^{4 to} R ⁷ is independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted group; An alkylthio group having 1 to 6 carbon atoms, a halogen group, a substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms is represented. L represents a monoanionic ligand.

A specific example of R ¹¹ is the same as that in the general formula (G1). Specific examples of R ^{2 to} R ⁷ are the same as those in General Formula (G7). A specific example of L is the same as in General Formula (G8).

Another embodiment of the present invention is an organometallic complex represented by General Formula (G4). In the organometallic complex represented by General Formula (G4), in the organometallic complex represented by General Formula (G8), R ¹ is a substituted or unsubstituted alkyl group having 5 to 10 carbon atoms, and M is iridium. (Ir). Therefore, the organometallic complex having the structure represented by the general formula (G4) is also represented by the general formula (G8).

In General Formula (G4), R ¹² represents a substituted or unsubstituted alkyl group having 5 to 10 carbon atoms. R ² represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted phenyl group, and R ³ represents hydrogen, or substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. Each of R ^{4 to} R ⁷ is independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted group; An alkylthio group having 1 to 6 carbon atoms, a halogen group, a substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms is represented. L represents a monoanionic ligand.

Note that a specific example of R ¹² is the same as that in the general formula (G2). Specific examples of R ^{2 to} R ⁷ are the same as those in General Formula (G7). A specific example of L is the same as in General Formula (G8).

Another embodiment of the present invention is an organometallic complex represented by General Formula (G9). The organometallic complex represented by General Formula (G9) is an organometallic complex having a structure represented by General Formula (G7).

In General Formula (G9), R ¹ represents a substituted or unsubstituted branched alkyl group having 4 or more carbon atoms and a straight chain carbon number of 3 or more, or a substituted or unsubstituted carbon atom having 5 to 5 carbon atoms. Represents 10 alkyl groups. R ² represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted phenyl group, and R ³ represents hydrogen, or substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. Each of R ^{4 to} R ⁷ is independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted group; An alkylthio group having 1 to 6 carbon atoms, a halogen group, a substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms is represented. M is a central metal and represents a Group 9 element or a Group 10 element.

Note that specific examples of R ^{1 to} R ⁷ and M are the same as those in the general formula (G7).

Another embodiment of the present invention is an organometallic complex represented by General Formula (G5). In the organometallic complex represented by the general formula (G5), in the organometallic complex represented by the general formula (G9), R ¹ has a substituted or unsubstituted carbon number of 4 or more and a linear carbon number of 3 The branched alkyl group as described above is used, and M is iridium (Ir). Therefore, the organometallic complex having a structure represented by General Formula (G5) is also represented by General Formula (G9).

In General Formula (G5), R ¹¹ represents a substituted or unsubstituted branched alkyl group having 4 or more carbon atoms and a straight chain carbon number of 3 or more. R ² represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted phenyl group, and R ³ represents hydrogen, or substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. Each of R ^{4 to} R ⁷ is independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted group; An alkylthio group having 1 to 6 carbon atoms, a halogen group, a substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms is represented.

A specific example of R ¹¹ is the same as that in the general formula (G1). Specific examples of R ^{2 to} R ⁷ are the same as those in General Formula (G7).

Another embodiment of the present invention is an organometallic complex represented by General Formula (G6). In the organometallic complex represented by the general formula (G6), in the organometallic complex represented by the general formula (G9), R ¹ is a substituted or unsubstituted alkyl group having 5 to 10 carbon atoms, and M is iridium. (Ir). Therefore, the organometallic complex having a structure represented by General Formula (G6) is also represented by General Formula (G9).

In General Formula (G6), R ¹² represents a substituted or unsubstituted alkyl group having 5 to 10 carbon atoms. R ² represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted phenyl group, and R ³ represents hydrogen, or substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. Each of R ^{4 to} R ⁷ is independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted group; An alkylthio group having 1 to 6 carbon atoms, a halogen group, a substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms is represented.

Note that a specific example of R ¹² is the same as that in the general formula (G2). Specific examples of R ^{2 to} R ⁷ are the same as those in General Formula (G7).

<< Method for Synthesizing Pyrimidine Derivative Represented by General Formula (G0) >>
An example of a synthesis method of a pyrimidine derivative represented by the following general formula (G0) will be described. The pyrimidine derivative represented by the following general formula (G0) can be synthesized by, for example, the following simple synthesis scheme (a) or (b).

In General Formula (G0), R ¹ represents a substituted or unsubstituted branched alkyl group having 4 or more carbon atoms and a straight chain carbon number of 3 or more, or a substituted or unsubstituted carbon atom having 5 to 5 carbon atoms. Represents 10 alkyl groups. R ² represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted phenyl group, and R ³ represents hydrogen, or substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. Each of R ^{4 to} R ⁷ is independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted group; An alkylthio group having 1 to 6 carbon atoms, a halogen group, a substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms is represented.
Represents.

For example, the pyrimidine derivative represented by the general formula (G0) can be obtained by reacting 1,3-diketone (A1) and amidine (A2) as shown in the synthesis scheme (a).

In the general formula (G0), when R ³ is hydrogen, as shown in non-patent literature (H. Brenereck, R. Gomper, G. Morlock, “Chemiche Berichte”, 90, 942 (1957)). 1,3-diketone (A1) and formamide are heated and reacted under an acid catalyst.

In the synthesis scheme (a), R ¹ represents a substituted or unsubstituted branched alkyl group having 4 or more carbon atoms and a straight chain carbon number of 3 or more, or a substituted or unsubstituted carbon group having 5 to 5 carbon atoms. Represents 10 alkyl groups. R ² represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted phenyl group, and R ³ represents hydrogen, or substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. Each of R ^{4 to} R ⁷ is independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted group; An alkylthio group having 1 to 6 carbon atoms, a halogen group, a substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms is represented.

The pyrimidine derivative represented by the general formula (G0) is obtained by cross-coupling the halogenated pyrimidine compound (A1 ′) and the Grignard reagent (A2 ′) as shown in the synthesis scheme (b). .

In the synthesis scheme (b), X ¹ and X ² represent halogen, and R ¹ is a substituted or unsubstituted branched alkyl group having 4 or more carbon atoms and 3 or more linear carbon atoms, or Represents a substituted or unsubstituted alkyl group having 5 to 10 carbon atoms. R ² represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted phenyl group, and R ³ represents hydrogen, or substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. Each of R ^{4 to} R ⁷ is independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted group; An alkylthio group having 1 to 6 carbon atoms, a halogen group, a substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms is represented.

Since the above-mentioned (A1), (A2), (A1 ′), and (A2 ′) are commercially available or can be synthesized, there are many pyrimidine derivatives represented by the general formula (G0). Can be synthesized. Therefore, the organometallic complex which is one embodiment of the present invention has a feature that the variation of the ligand is abundant.

<< Method for Synthesizing Organometallic Complex of One Embodiment of the Present Invention Represented by General Formula (G3), (G4), (G5), or (G6) >>
Next, among the organometallic complexes of one embodiment of the present invention formed by orthometalation of the 4-arylpyrimidine derivative represented by General Formula (G0), the following General Formula (G3), ( G4) A method for synthesizing the organometallic complex represented by (G5) or (G6) will be described.

R ¹¹ represents a branched or unsubstituted alkyl group having 4 or more carbon atoms and a straight chain having 3 or more carbon atoms. R ¹² represents a substituted or unsubstituted alkyl group having 5 to 10 carbon atoms. R ² represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted phenyl group, and R ³ represents hydrogen, or substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. Each of R ^{4 to} R ⁷ is independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted group; An alkylthio group having 1 to 6 carbon atoms, a halogen group, a substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms is represented. L represents a monoanionic ligand.

<Method for Synthesizing Organometallic Complex of One Embodiment of the Present Invention Represented by General Formula (G3) or (G4)>
First, as shown in the following synthesis scheme (c), a pyrimidine derivative represented by the general formula (G0) and an iridium halide compound (iridium chloride, iridium bromide, iridium iodide, etc., preferably iridium trichloride water A non-solvent, alcohol solvent (glycerol, ethylene glycol, 2-methoxyethanol, 2-ethoxyethanol, etc.) alone, or a mixed solvent of one or more alcohol solvents and water, and inert gas By heating in an atmosphere, a binuclear complex (B) which is a kind of organometallic complex having a structure crosslinked with halogen and which is a novel substance can be obtained. There is no particular limitation on the heating means, and an oil bath, a sand bath, or an aluminum block may be used. Moreover, it is also possible to use a microwave as a heating means.

In Synthesis Scheme (c), X represents halogen, and R ¹ represents a substituted or unsubstituted branched alkyl group having 4 or more carbon atoms and a straight chain carbon number of 3 or more, or substituted or unsubstituted A substituted alkyl group having 5 to 10 carbon atoms is represented. R ² represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted phenyl group, and R ³ represents hydrogen, or substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. Each of R ^{4 to} R ⁷ is independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted group; An alkylthio group having 1 to 6 carbon atoms, a halogen group, a substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms is represented.

Furthermore, as shown in the following synthesis scheme (d), the binuclear complex (B) obtained in the above-mentioned synthesis scheme (c) is reacted with the monoanionic ligand raw material HL in an inert gas atmosphere. By doing so, the proton of HL is eliminated and L is coordinated to the central metal Ir, whereby the organometallic complex (C) is obtained. Here, in the organometallic complex (C), when R ¹ represents a substituted or unsubstituted branched alkyl group having 4 or more carbon atoms and a straight chain carbon number of 3 or more, the general formula ( When the organometallic complex represented by G3) and R ¹ represents a substituted or unsubstituted alkyl group having 5 to 10 carbon atoms, the organometallic complex represented by General Formula (G4) is obtained. Therefore, although the method for synthesizing the organometallic complex (C) is shown, the method for synthesizing the organometallic complex of one embodiment of the present invention represented by the general formula (G3) or (G4) is also the same. The heating means is not particularly limited, and an oil bath, a sand bath, or an aluminum block may be used. Moreover, it is also possible to use a microwave as a heating means.

In the synthesis scheme (d), L represents a monoanionic ligand, X represents a halogen, R ¹ has a substituted or unsubstituted carbon number of 4 or more, and a linear carbon number of 3 or more. It represents a certain branched alkyl group or a substituted or unsubstituted alkyl group having 5 to 10 carbon atoms. R ² represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted phenyl group, and R ³ represents hydrogen, or substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. Each of R ^{4 to} R ⁷ is independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted group; An alkylthio group having 1 to 6 carbon atoms, a halogen group, a substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms is represented.

In one embodiment of the present invention, as described above, in order to obtain an ortho metal complex having a pyrimidine derivative as a ligand, a substituent is introduced at the 6-position (ie, R ¹ ) of the pyrimidine. In particular, as R ¹ , a substituted or unsubstituted branched alkyl group having 4 or more carbon atoms and a straight chain carbon number of 3 or more, or a substituted or unsubstituted alkyl group having 5 to 10 carbon atoms is used. ing. For this reason, it suppresses that the binuclear metal complex bridge | crosslinked with the halogen produced | generated in the synthesis scheme (c) decomposes | disassembles during reaction represented by the synthesis scheme (d), and obtains a remarkably high yield. Can do.

In addition, the monoanionic ligand L in the organometallic complex (C), that is, in the general formula (G3) or (G4) is a monoanionic bidentate chelate ligand having a beta diketone structure, carboxyl A monoanionic bidentate chelate ligand having a phenolic group, a monoanionic bidentate chelate ligand having a phenolic hydroxyl group, or a monoanionic bidentate chelate having two coordination elements each of which is nitrogen A ligand is preferred. In particular, a monoanionic bidentate chelate ligand having a beta diketone structure is preferable because the beta diketone structure increases the solubility of the organometallic complex in an organic solvent and facilitates purification. Further, it is preferable to have a beta diketone structure because an organometallic complex having high luminous efficiency can be obtained. Moreover, sublimation property increases by having a beta diketone structure, and there exists an advantage that it is excellent in vapor deposition performance.

The monoanionic ligand is preferably any one of the general formulas (L1) to (L7). These ligands are effective because they have high coordination ability and can be obtained at low cost.

In the general formulas (L1) to (L7), R ^{71 to} R ¹⁰⁹ are each independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, a halogen group, a vinyl group, or a substituted or unsubstituted carbon number. It represents a 1-4 haloalkyl group, a substituted or unsubstituted alkoxy group having 1 to 4 carbon atoms, or a substituted or unsubstituted alkylthio group having 1 to 4 carbon atoms. A ^{1 to} A ³ each independently represent nitrogen, sp ² hybrid carbon bonded to hydrogen, or sp ² carbon bonded to a substituent R, wherein the substituent R is an alkyl group having 1 to 4 carbon atoms, A halogen group, a C1-C4 haloalkyl group, or a phenyl group is represented.

<Method for Synthesizing Organometallic Complex of One Embodiment of the Present Invention Represented by General Formula (G5) or (G6)>
The organometallic complex which is one embodiment of the present invention represented by the general formula (G5) or (G6) can be synthesized by the following synthesis scheme (e). That is, a pyrimidine derivative represented by the general formula (G0) and an iridium halide compound (iridium chloride, iridium bromide, iridium iodide, etc., preferably iridium trichloride hydrate), or an iridium organometallic complex compound ( An organometallic complex (D) can be obtained by heating after mixing with an acetylacetonato complex, a diethyl sulfide complex, etc.). Here, in the organometallic complex (D), when R ¹ represents a substituted or unsubstituted branched alkyl group having 4 or more carbon atoms and a straight chain carbon number of 3 or more, the general formula ( When an organometallic complex represented by G5) and R ¹ represents a substituted or unsubstituted alkyl group having 5 to 10 carbon atoms, an organometallic complex represented by General Formula (G6) is obtained. Therefore, although the method for synthesizing the organometallic complex (D) is shown, the method for synthesizing the organometallic complex of one embodiment of the present invention represented by the general formula (G5) or (G6) is also the same. In addition, in this heating process, a pyrimidine derivative represented by the general formula (G0) and an iridium halide compound or an iridium organometallic complex compound are mixed with an alcohol solvent (glycerol, ethylene glycol, 2-methoxyethanol, 2-ethoxy). It may be performed after dissolving in ethanol or the like. There is no particular limitation on the heating means, and an oil bath, a sand bath, or an aluminum block may be used. Moreover, it is also possible to use a microwave as a heating means.

In the synthesis scheme (e), R ¹ represents a substituted or unsubstituted branched alkyl group having 4 or more carbon atoms and a straight chain carbon number of 3 or more, or a substituted or unsubstituted carbon group having 5 to 5 carbon atoms. Represents 10 alkyl groups. R ² represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted phenyl group, and R ³ represents hydrogen, or substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. Each of R ^{4 to} R ⁷ is independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted group; An alkylthio group having 1 to 6 carbon atoms, a halogen group, a substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms is represented.

In one embodiment of the present invention, as described above, in order to obtain an ortho metal complex having a pyrimidine derivative as a ligand, a substituent is introduced at the 6-position (ie, R ¹ ) of the pyrimidine. In particular, as R ¹ , a substituted or unsubstituted branched alkyl group having 4 or more carbon atoms and a straight chain carbon number of 3 or more, or a substituted or unsubstituted alkyl group having 5 to 10 carbon atoms is used. Therefore, the yield in the synthesis scheme (e) can be increased. R ¹ is a substituted or unsubstituted branched alkyl group having 4 or more carbon atoms and a straight chain carbon number of 3 or more, or a substituted or unsubstituted alkyl group having 5 to 10 carbon atoms. Thus, the formation of meridional isomers can be suppressed. In general, it is known that meridional isomers have lower luminous efficiency than facial isomers and are easily reacted by photoexcitation. In the structure of one embodiment of the present invention, since R ¹ has a long-chain alkyl group, the formation of meridional isomers is suppressed. Therefore, the formation of meridional isomers can be suppressed by using the organometallic complex according to one embodiment of the present invention. When the organometallic complex according to one embodiment of the present invention is used for an EL element, efficiency and reliability are improved. Contributes to improvement. Further, as compared with the case of using a tert- butyl group in R ^1, is characterized in that a high solubility in organic solvents.

Although an example of a synthesis method has been described above, the organometallic complex which is one embodiment of the disclosed invention may be synthesized by any other synthesis method.

Specific structural formulas of organometallic complexes of one embodiment of the present invention are listed in the following structural formulas (100) to (117). Note that one embodiment of the present invention is not limited thereto.

Note that the organometallic complexes represented by the structural formulas (100) to (117) may have stereoisomers depending on the type of the ligand, but the organometallic complexes of one embodiment of the present invention include these. All isomers are also included.

The above-described organometallic complex which is one embodiment of the present invention can emit phosphorescence and has a wide emission spectrum in a wavelength range from red to green, and thus can be used as a light-emitting material or a light-emitting substance of a light-emitting element.

By using the organometallic complex of one embodiment of the present invention, a light-emitting element, a light-emitting device, an electronic device, or a lighting device with high emission efficiency can be realized. Alternatively, a light-emitting element, a light-emitting device, an electronic device, or a lighting device with low power consumption can be realized.

Further, by using the organometallic complex of one embodiment of the present invention, a highly reliable light-emitting element, light-emitting device, electronic device, or lighting device can be realized.

In this embodiment, the structures described in the other embodiments can be combined as appropriate.

(Embodiment 2)
In this embodiment, as one embodiment of the present invention, a light-emitting element using the organometallic complex described in Embodiment 1 for a light-emitting layer will be described with reference to FIG.

FIG. 1A illustrates a light-emitting element including an EL layer 102 between a first electrode 101 and a second electrode 103. The EL layer 102 includes a light emitting layer 113. The light-emitting layer 113 includes the organometallic complex of one embodiment of the present invention described in Embodiment 1.

When a voltage is applied to such a light-emitting element, holes injected from the first electrode 101 side and electrons injected from the second electrode 103 side are regenerated in the light-emitting layer 113. Bonds, bringing the organometallic complex into an excited state. Light is emitted when the organometallic complex in the excited state returns to the ground state. As described above, the organometallic complex which is one embodiment of the present invention functions as a light-emitting substance in a light-emitting element. Note that in the light-emitting element described in this embodiment, the first electrode 101 functions as an anode and the second electrode 103 functions as a cathode.

The first electrode 101 functioning as an anode is preferably formed using a metal, an alloy, an electrically conductive compound, a mixture thereof, or the like having a high work function (specifically, 4.0 eV or more). Specifically, for example, indium tin oxide (ITO), indium oxide-tin oxide containing silicon or silicon oxide, indium zinc oxide (indium zinc oxide), tungsten oxide, and zinc oxide are used. Examples thereof include indium oxide. In addition, gold, platinum, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, or the like can be used.

However, in the case where the layer formed in contact with the first electrode 101 in the EL layer 102 is formed using a composite material in which an organic compound and an electron acceptor (acceptor) described later are mixed. As the substance used for the first electrode 101, various metals, alloys, electrically conductive compounds, mixtures thereof, and the like can be used regardless of the work function. For example, aluminum, silver, an alloy containing aluminum (for example, Al—Si), or the like can also be used.

The first electrode 101 can be formed by, for example, a sputtering method or a vapor deposition method (including a vacuum vapor deposition method).

The EL layer 102 formed over the first electrode 101 includes at least the light-emitting layer 113 and includes the organometallic complex which is one embodiment of the present invention. Various substances can be used for part of the EL layer 102, and either a low molecular compound or a high molecular compound can be used. Note that the substance forming the EL layer 102 includes not only an organic compound but also a structure including an inorganic compound in part.

In addition to the light-emitting layer 113, the EL layer 102 includes a hole-injecting layer 111 containing a substance having a high hole-injecting property and a hole containing a substance having a high hole-transporting property as shown in FIG. It is formed by stacking a transport layer 112, an electron transport layer 114 containing a substance having a high electron transport property, an electron injection layer 115 containing a substance having a high electron injection property, and the like, as appropriate.

The hole injection layer 111 is a layer containing a substance having a high hole injection property. Substances with high hole injection properties include molybdenum oxide, titanium oxide, vanadium oxide, rhenium oxide, ruthenium oxide, chromium oxide, zirconium oxide, hafnium oxide, tantalum oxide, silver oxide, Metal oxides such as tungsten oxide and manganese oxide can be used. Alternatively, a phthalocyanine-based compound such as phthalocyanine (abbreviation: H ₂ Pc) or copper (II) phthalocyanine (abbreviation: CuPc) can be used.

In addition, 4,4 ′, 4 ″ -tris (N, N-diphenylamino) triphenylamine (abbreviation: TDATA), 4,4 ′, 4 ″ -tris [N- ( 3-methylphenyl) -N-phenylamino] triphenylamine (abbreviation: MTDATA), 4,4′-bis [N- (4-diphenylaminophenyl) -N-phenylamino] biphenyl (abbreviation: DPAB), 4 , 4′-bis (N- {4- [N ′-(3-methylphenyl) -N′-phenylamino] phenyl} -N-phenylamino) biphenyl (abbreviation: DNTPD), 1,3,5-tris [N- (4-diphenylaminophenyl) -N-phenylamino] benzene (abbreviation: DPA3B), 3- [N- (9-phenylcarbazol-3-yl) -N-phenylamino]- -Phenylcarbazole (abbreviation: PCzPCA1), 3,6-bis [N- (9-phenylcarbazol-3-yl) -N-phenylamino] -9-phenylcarbazole (abbreviation: PCzPCA2), 3- [N- ( An aromatic amine compound such as 1-naphthyl) -N- (9-phenylcarbazol-3-yl) amino] -9-phenylcarbazole (abbreviation: PCzPCN1) can be used.

Furthermore, a high molecular compound (an oligomer, a dendrimer, a polymer, etc.) can also be used. For example, poly (N-vinylcarbazole) (abbreviation: PVK), poly (4-vinyltriphenylamine) (abbreviation: PVTPA), poly [N- (4- {N ′-[4- (4-diphenylamino)] Phenyl] phenyl-N′-phenylamino} phenyl) methacrylamide] (abbreviation: PTPDMA), poly [N, N′-bis (4-butylphenyl) -N, N′-bis (phenyl) benzidine] (abbreviation: Polymer compounds such as Poly-TPD). In addition, a polymer compound to which an acid such as poly (3,4-ethylenedioxythiophene) / poly (styrenesulfonic acid) (PEDOT / PSS), polyaniline / poly (styrenesulfonic acid) (PAni / PSS) is added is used. be able to.

As the hole injection layer 111, a composite material in which an organic compound and an electron acceptor (acceptor) are mixed may be used. Such a composite material is excellent in hole injecting property and hole transporting property because holes are generated in the organic compound by the electron acceptor. In this case, the organic compound is preferably a material excellent in transporting generated holes (a substance having a high hole-transport property).

As the organic compound used for the composite material, various compounds such as an aromatic amine compound, a carbazole derivative, an aromatic hydrocarbon, and a high molecular compound (such as an oligomer, a dendrimer, and a polymer) can be used. Note that the organic compound used for the composite material is preferably an organic compound having a high hole-transport property. Specifically, a substance having a hole mobility of 10 ⁻⁶ cm ² / Vs or higher is preferable. Note that other than these substances, any substance that has a property of transporting more holes than electrons may be used. Below, the organic compound which can be used for a composite material is listed concretely.

Examples of an organic compound that can be used for the composite material include TDATA, MTDATA, DPAB, DNTPD, DPA3B, PCzPCA1, PCzPCA2, PCzPCN1, 4,4′-bis [N- (1-naphthyl) -N-phenylamino]. Biphenyl (abbreviation: NPB or α-NPD), N, N′-bis (3-methylphenyl) -N, N′-diphenyl- [1,1′-biphenyl] -4,4′-diamine (abbreviation: TPD) ), 4-phenyl-4 ′-(9-phenylfluoren-9-yl) triphenylamine (abbreviation: BPAFLP) and the like, and 4,4′-di (N-carbazolyl) biphenyl (abbreviation: CBP), 1,3,5-tris [4- (N-carbazolyl) phenyl] benzene (abbreviation: TCPB), 9- [4- (N- Rubazolyl)] phenyl-10-phenylanthracene (abbreviation: CzPA), 9-phenyl-3- [4- (10-phenyl-9-anthryl) phenyl] -9H-carbazole (abbreviation: PCzPA), 1,4-bis A carbazole derivative such as [4- (N-carbazolyl) phenyl] -2,3,5,6-tetraphenylbenzene can be used.

2-tert-butyl-9,10-di (2-naphthyl) anthracene (abbreviation: t-BuDNA), 2-tert-butyl-9,10-di (1-naphthyl) anthracene, 9,10-bis (3,5-diphenylphenyl) anthracene (abbreviation: DPPA), 2-tert-butyl-9,10-bis (4-phenylphenyl) anthracene (abbreviation: t-BuDBA), 9,10-di (2-naphthyl) ) Anthracene (abbreviation: DNA), 9,10-diphenylanthracene (abbreviation: DPAnth), 2-tert-butylanthracene (abbreviation: t-BuAnth), 9,10-bis (4-methyl-1-naphthyl) anthracene ( Abbreviations: DMNA), 9,10-bis [2- (1-naphthyl) phenyl] -2-tert-butylanthracene, 9, 0- bis [2- (1-naphthyl) phenyl] anthracene, and 2,3,6,7-tetramethyl-9,10-di (1-naphthyl) aromatic hydrocarbon compounds such as anthracene.

Further, 2,3,6,7-tetramethyl-9,10-di (2-naphthyl) anthracene, 9,9′-bianthryl, 10,10′-diphenyl-9,9′-bianthryl, 10,10 ′ -Bis (2-phenylphenyl) -9,9'-bianthryl, 10,10'-bis [(2,3,4,5,6-pentaphenyl) phenyl] -9,9'-bianthryl, anthracene, tetracene , Rubrene, perylene, 2,5,8,11-tetra (tert-butyl) perylene, pentacene, coronene, 4,4'-bis (2,2-diphenylvinyl) biphenyl (abbreviation: DPVBi), 9,10- An aromatic hydrocarbon compound such as bis [4- (2,2-diphenylvinyl) phenyl] anthracene (abbreviation: DPVPA) can be used.

Examples of the electron acceptor include organic compounds such as 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F ₄ -TCNQ), chloranil, and transition metal oxidation. You can list things. In addition, oxides of metals belonging to Groups 4 to 8 in the periodic table can be given. Specifically, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide are preferable because of their high electron accepting properties. Among these, molybdenum oxide is especially preferable because it is stable in the air, has a low hygroscopic property, and is easy to handle.

Note that a composite material may be formed using the above-described electron acceptor with the above-described polymer compound such as PVK, PVTPA, PTPDMA, or Poly-TPD and used for the hole-injection layer 111.

The hole transport layer 112 is a layer containing a substance having a high hole transport property. As a substance having a high hole-transport property, NPB, TPD, BPAFLP, 4,4′-bis [N- (9,9-dimethylfluoren-2-yl) -N-phenylamino] biphenyl (abbreviation: DFLDPBi), An aromatic amine compound such as 4,4′-bis [N- (spiro-9,9′-bifluoren-2-yl) -N-phenylamino] biphenyl (abbreviation: BSPB) can be used. The substances described here are mainly substances having a hole mobility of 10 ⁻⁶ cm ² / Vs or higher. Note that other than these substances, any substance that has a property of transporting more holes than electrons may be used. Note that the layer containing a substance having a high hole-transport property is not limited to a single layer, and two or more layers containing the above substances may be stacked.

For the hole transport layer 112, a carbazole derivative such as CBP, CzPA, or PCzPA, or an anthracene derivative such as t-BuDNA, DNA, or DPAnth may be used.

For the hole-transport layer 112, a high molecular compound such as PVK, PVTPA, PTPDMA, or Poly-TPD can be used.

The light-emitting layer 113 is a layer including an organometallic complex which is one embodiment of the present invention as described in Embodiment 1. The light-emitting layer 113 may be formed using a thin film including the organometallic complex of one embodiment of the present invention, or a substance having triplet excitation energy larger than that of the organometallic complex of one embodiment of the present invention is used as a host. The light-emitting layer 113 may be formed using a thin film in which the organometallic complex which is one embodiment of the present invention is dispersed as a guest. This can prevent light emission from the organometallic complex from being quenched due to the concentration. The triplet excitation energy is an energy difference between the ground state and the triplet excited state.

The electron transport layer 114 is a layer containing a substance having a high electron transport property. As a substance having a high electron-transport property, Alq ₃ , tris (4-methyl-8-quinolinolato) aluminum (abbreviation: Almq ₃ ), bis (10-hydroxybenzo [h] quinolinato) beryllium (abbreviation: BeBq ₂ ), BAlq , Zn (BOX) ₂ , and bis [2- (2-hydroxyphenyl) benzothiazolate] zinc (abbreviation: Zn (BTZ) ₂ ). 2- (4-biphenylyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis [5- (p-tert-butyl) Phenyl) -1,3,4-oxadiazol-2-yl] benzene (abbreviation: OXD-7), 3- (4-tert-butylphenyl) -4-phenyl-5- (4-biphenylyl) -1 , 2,4-triazole (abbreviation: TAZ), 3- (4-tert-butylphenyl) -4- (4-ethylphenyl) -5- (4-biphenylyl) -1,2,4-triazole (abbreviation: p-EtTAZ), bathophenanthroline (abbreviation: BPhen), bathocuproin (abbreviation: BCP), 4,4′-bis (5-methylbenzoxazol-2-yl) stilbene (abbreviation: BzOs), etc. Aromatic aromatic compounds can also be used. Further, poly (2,5-pyridine-diyl) (abbreviation: PPy), poly [(9,9-dihexylfluorene-2,7-diyl) -co- (pyridine-3,5-diyl)] (abbreviation: PF-Py), poly [(9,9-dioctylfluorene-2,7-diyl) -co- (2,2′-bipyridine-6,6′-diyl)] (abbreviation: PF-BPy) A high molecular compound can also be used. The substances mentioned here are mainly substances having an electron mobility of 10 ⁻⁶ cm ² / Vs or higher. Note that other than the above substances, any substance that has a property of transporting more electrons than holes may be used for the electron-transport layer.

Further, the electron-transport layer is not limited to a single layer, and two or more layers including the above substances may be stacked.

The electron injection layer 115 is a layer containing a substance having a high electron injection property. For the electron injecting layer 115, an alkali metal such as lithium, cesium, calcium, lithium fluoride, cesium fluoride, calcium fluoride, lithium oxide, or a compound thereof can be used. Alternatively, a rare earth metal compound such as erbium fluoride can be used. In addition, a substance constituting the electron transport layer 114 described above can be used.

Alternatively, a composite material obtained by mixing an organic compound and an electron donor (donor) may be used for the electron injection layer 115. Such a composite material is excellent in electron injecting property and electron transporting property because electrons are generated in the organic compound by the electron donor. In this case, the organic compound is preferably a material excellent in transporting the generated electrons. Specifically, for example, a substance (metal complex, heteroaromatic compound, or the like) constituting the electron transport layer 114 described above is used. Can be used. The electron donor may be any substance that exhibits an electron donating property to the organic compound. Specifically, alkali metals, alkaline earth metals, and rare earth metals are preferable, and lithium, cesium, magnesium, calcium, erbium, ytterbium, and the like can be given. Alkali metal oxides and alkaline earth metal oxides are preferable, and lithium oxide, calcium oxide, barium oxide, and the like can be given. A Lewis base such as magnesium oxide can also be used. Alternatively, an organic compound such as tetrathiafulvalene (abbreviation: TTF) can be used.

Note that the hole injection layer 111, the hole transport layer 112, the light-emitting layer 113, the electron transport layer 114, and the electron injection layer 115 described above are formed by an evaporation method (including a vacuum evaporation method), an inkjet method, a coating method, or the like. Can be formed by a method.

The second electrode 103 that functions as a cathode is preferably formed using a metal, an alloy, an electrically conductive compound, a mixture thereof, or the like with a low work function (preferably 3.8 eV or less). Specifically, elements belonging to Group 1 or Group 2 of the periodic table of elements, that is, alkali metals such as lithium and cesium, and alkaline earth metals such as magnesium, calcium, and strontium, and alloys containing these (for example, In addition to rare earth metals such as Mg—Ag, Al—Li), europium, ytterbium, and alloys containing these, aluminum, silver, and the like can be used.

However, in the case where the layer formed in contact with the second electrode 103 in the EL layer 102 uses a composite material in which the above-described organic compound and an electron donor (donor) are mixed, the work function is Regardless of the size, various conductive materials such as indium oxide-tin oxide containing Al, Ag, ITO, silicon, or silicon oxide can be used.

Note that when the second electrode 103 is formed, a vacuum evaporation method or a sputtering method can be used. Moreover, when using a silver paste etc., the apply | coating method, the inkjet method, etc. can be used.

In the above light-emitting element, current flows due to a potential difference generated between the first electrode 101 and the second electrode 103, and light is emitted by recombination of holes and electrons in the EL layer 102. Then, the emitted light is extracted outside through one or both of the first electrode 101 and the second electrode 103. Accordingly, one or both of the first electrode 101 and the second electrode 103 is an electrode having a property of transmitting visible light.

With the use of the light-emitting element described in this embodiment, a passive matrix light-emitting device or an active matrix light-emitting device in which driving of the light-emitting element is controlled by a transistor can be manufactured.

Note that there is no particular limitation on the structure of the transistor in the case of manufacturing an active matrix light-emitting device. For example, a staggered or inverted staggered transistor can be used as appropriate. Also, the driving circuit formed on the substrate may be composed of N-type and P-type transistors, or may be composed of only N-type transistors or only P-type transistors. Further, there is no particular limitation on the crystallinity of a semiconductor film used for the transistor. For example, an amorphous semiconductor film, a crystalline semiconductor film, or the like can be used. As a material for the semiconductor film, an oxide semiconductor or the like can be used in addition to a simple substance such as silicon.

Note that in this embodiment, the organometallic complex which is one embodiment of the present invention used in the light-emitting layer 113 has a wide emission spectrum in a wavelength range from red to green. Therefore, a light emitting element with high color rendering properties can be realized.

In addition, since the light-emitting element of this embodiment includes the organometallic complex of one embodiment of the present invention, a light-emitting element with high emission efficiency can be realized. In addition, a light-emitting element with low power consumption can be realized. In addition, a highly reliable light-emitting element can be realized.

In this embodiment, the structures described in the other embodiments can be combined as appropriate.

(Embodiment 3)
The light-emitting element of one embodiment of the present invention may have a plurality of light-emitting layers. By providing a plurality of light emitting layers and emitting light from each of the light emitting layers, light emission in which a plurality of light emissions are mixed can be obtained. Thus, for example, white light can be obtained. In this embodiment, an embodiment of a light-emitting element having a plurality of light-emitting layers will be described with reference to FIG.

FIG. 1B illustrates a light-emitting element including the EL layer 102 between the first electrode 101 and the second electrode 103. Since the EL layer 102 includes the first light-emitting layer 213 and the second light-emitting layer 215, the light-emitting element illustrated in FIG. 1B emits light in the first light-emitting layer 213 and light emission in the second light-emitting layer 215. Can be obtained. A separation layer 214 is preferably provided between the first light-emitting layer 213 and the second light-emitting layer 215.

In this embodiment, a light-emitting element in which the first light-emitting layer 213 includes an organic compound that emits blue light and the second light-emitting layer 215 includes the organometallic complex of one embodiment of the present invention will be described. One aspect of this is not limited to this.

An organometallic complex which is one embodiment of the present invention may be used for the first light-emitting layer 213 and another light-emitting substance may be applied to the second light-emitting layer 215.

The EL layer 102 may include three or more light-emitting layers.

When a voltage is applied so that the potential of the first electrode 101 is higher than the potential of the second electrode 103, a current flows between the first electrode 101 and the second electrode 103, and the first light emitting layer In 213, the second light-emitting layer 215, or the separation layer 214, holes and electrons are recombined. The generated excitation energy is distributed to both the first light-emitting layer 213 and the second light-emitting layer 215, and is included in the first light-emitting substance and the second light-emitting layer 215 included in the first light-emitting layer 213. The second luminescent material is brought into an excited state. The first light-emitting substance and the second light-emitting substance that are in the excited state emit light when returning to the ground state.

The first light-emitting layer 213 includes perylene, 2,5,8,11-tetra (tert-butyl) perylene (abbreviation: TBP), DPVBi, 4,4′-bis [2- (N-ethylcarbazole-3). -Yl) vinyl] biphenyl (abbreviation: BCzVBi), BAlq, bis (2-methyl-8-quinolinolato) gallium chloride (Gamq ₂ Cl), bis {2- [3,5-bis (tri Fluoromethyl) phenyl] pyridinato-N, C ^{2 ′} } iridium (III) picolinate (abbreviation: [Ir (CF ₃ ppy) ₂ (pic)]), bis [2- (4,6-difluorophenyl) pyridinato-N , C ^{2 ′} ] iridium (III) acetylacetonate (abbreviation: [FIr (acac)]), bis [2- (4,6-difluorophenyl) pyridinato —N, C ^{2 ′} ] iridium (III) picolinate (abbreviation: FIrpic), bis [2- (4,6-difluorophenyl) pyridinato-N, C ^{2 ′} ] iridium (III) tetra (1-pyrazolyl) borate ( The first light-emitting substance typified by a phosphorescent compound such as abbreviation FIr6) is included, and light emission having a peak of an emission spectrum at 450 to 510 nm (that is, blue to blue green) is obtained.

In addition, when the first light-emitting substance is a fluorescent compound, the first light-emitting layer 213 uses a substance having a singlet excitation energy higher than that of the first light-emitting substance as the first host. A layer in which a light-emitting substance is dispersed as a guest is preferable. In the case where the first light-emitting substance is a phosphorescent compound, a layer having a triplet excitation energy higher than that of the first light-emitting substance is used as the first host, and the first light-emitting substance is dispersed as a guest. It is preferable that As the first host, DNA, t-BuDNA, and the like can be used in addition to NPB, CBP, TCTA, and the like described above. The singlet excitation energy is an energy difference between the ground state and the singlet excited state.

The second light-emitting layer 215 includes the organometallic complex that is one embodiment of the present invention, and can emit red to green light. The structure of the second light-emitting layer 215 may be the same as that of the light-emitting layer 113 described in Embodiment 2.

Specifically, the separation layer 214 can be formed using the above-described TPAQn, NPB, CBP, TCTA, Znpp ₂ , ZnBOX, or the like. In this manner, by providing the separation layer 214, it is possible to prevent a problem that the light emission intensity of only one of the first light-emitting layer 213 and the second light-emitting layer 215 is increased. Note that the separation layer 214 is not necessarily provided and may be provided as appropriate in order to adjust the ratio between the light emission intensity of the first light-emitting layer 213 and the light emission intensity of the second light-emitting layer 215.

In addition to the light-emitting layer, the EL layer 102 includes a hole injection layer 111, a hole transport layer 112, an electron transport layer 114, and an electron injection layer 115. The structure of these layers is also described in the embodiment. The structure of each layer described in 2 may be applied. However, these layers are not necessarily required, and may be provided as appropriate depending on the characteristics of the element.

Note that the structure described in this embodiment can be combined with any of the structures described in other embodiments as appropriate.

(Embodiment 4)
In this embodiment, as one embodiment of the present invention, a structure including a plurality of EL layers in a light-emitting element (hereinafter referred to as a stacked element) will be described with reference to FIG. This light-emitting element includes a plurality of EL layers (the first EL layer 700 and the second EL layer 701 in FIG. 1C) between the first electrode 101 and the second electrode 103. Type light emitting device. Note that although this embodiment mode shows a case where there are two EL layers, three or more layers may be used.

In this embodiment, the structure described in Embodiment 2 may be applied to the first electrode 101 and the second electrode 103.

In this embodiment, all of the plurality of EL layers may have a structure similar to that of the EL layer described in Embodiment 2, or part of the EL layers may have the same structure. That is, the first EL layer 700 and the second EL layer 701 may have the same structure or different structures, and the same structure as that in Embodiment 2 can be applied to the structure.

In FIG. 1C, a charge generation layer 305 is provided between the first EL layer 700 and the second EL layer 701. The charge generation layer 305 has a function of injecting electrons into one EL layer and injecting holes into the other EL layer when voltage is applied to the first electrode 101 and the second electrode 103. In this embodiment mode, when a voltage is applied to the first electrode 101 so that the potential is higher than that of the second electrode 103, electrons are injected from the charge generation layer 305 to the first EL layer 700, and Holes are injected into the second EL layer 701.

Note that the charge generation layer 305 preferably has a property of transmitting visible light from the viewpoint of light extraction efficiency. In addition, the charge generation layer 305 functions even when it has lower conductivity than the first electrode 101 and the second electrode 103.

The charge generation layer 305 has a structure including an organic compound having a high hole transporting property and an electron acceptor (acceptor), and a structure including an organic compound having a high electron transporting property and an electron donor (donor). May be. Moreover, both these structures may be laminated | stacked.

In the case where an electron acceptor is added to an organic compound having a high hole-transport property, examples of the organic compound having a high hole-transport property include NPB, TPD, TDATA, MTDATA, 4,4′-bis [ An aromatic amine compound such as N- (spiro-9,9′-bifluoren-2-yl) -N-phenylamino] biphenyl (abbreviation: BSPB) can be used. The substances described here are mainly substances having a hole mobility of 10 ⁻⁶ cm ² / Vs or higher. Note that other than the above substances, any organic compound that has a property of transporting more holes than electrons may be used.

Examples of the electron acceptor include 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F ₄ -TCNQ), chloranil, and the like. Moreover, a transition metal oxide can be mentioned. In addition, oxides of metals belonging to Groups 4 to 8 in the periodic table can be given. Specifically, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide are preferable because of their high electron accepting properties. Among these, molybdenum oxide is especially preferable because it is stable in the air, has a low hygroscopic property, and is easy to handle.

On the other hand, in the case where an electron donor is added to an organic compound having a high electron transport property, examples of the organic compound having a high electron transport property include Alq, Almq ₃ , BeBq ₂ , BAlq, quinoline skeleton or benzo A metal complex having a quinoline skeleton or the like can be used. In addition, a metal complex having an oxazole-based or thiazole-based ligand such as Zn (BOX) ₂ or Zn (BTZ) ₂ can also be used. In addition to metal complexes, PBD, OXD-7, TAZ, BPhen, BCP, and the like can also be used. The substances mentioned here are mainly substances having an electron mobility of 10 ⁻⁶ cm ² / Vs or higher. Note that other than the above substances, any organic compound that has a property of transporting more electrons than holes may be used.

As the electron donor, an alkali metal, an alkaline earth metal, a rare earth metal, a metal belonging to Group 13 in the periodic table, or an oxide or carbonate thereof can be used. Specifically, lithium, cesium, magnesium, calcium, ytterbium, indium, lithium oxide, cesium carbonate, or the like is preferably used. An organic compound such as tetrathianaphthacene may be used as an electron donor.

Note that by forming the charge generation layer 305 using the above-described material, an increase in driving voltage in the case where an EL layer is stacked can be suppressed.

Although a light-emitting element having two EL layers has been described in this embodiment mode, the present invention can be similarly applied to a light-emitting element in which three or more EL layers are stacked. As in the light-emitting element according to this embodiment, a plurality of EL layers are arranged between a pair of electrodes with a charge generation layer interposed therebetween, so that light emission in a high-luminance region can be performed while keeping the current density low. It is. Since the current density can be kept low, a long-life element can be realized. Further, when illumination is used as an application example, the voltage drop due to the resistance of the electrode material can be reduced, so that uniform light emission over a large area is possible. In addition, a light-emitting device that can be driven at a low voltage and has low power consumption can be realized.

Further, by making the light emission colors of the respective EL layers different, light emission of a desired color can be obtained as the whole light emitting element. For example, in a light-emitting element having two EL layers, a light-emitting element that emits white light as a whole of the light-emitting element by making the emission color of the first EL layer and the emission color of the second EL layer have a complementary relationship It is also possible to obtain The complementary color refers to a relationship between colors that become achromatic when mixed. That is, white light emission can be obtained by mixing light obtained from substances that emit light of complementary colors.

The same applies to a light-emitting element having three EL layers. For example, the emission color of the first EL layer is red, the emission color of the second EL layer is green, and the third EL layer. When the emission color of is blue, the entire light emitting element can emit white light.

Note that the structure described in this embodiment can be combined with any of the structures described in other embodiments as appropriate.

(Embodiment 5)
In this embodiment, a passive matrix light-emitting device and an active matrix light-emitting device each including the light-emitting element of one embodiment of the present invention will be described.

2 and 3 show examples of passive matrix light-emitting devices.

A light emitting device of a passive matrix type (also referred to as a simple matrix type) is provided so that a plurality of anodes arranged in stripes (bands) and a plurality of cathodes arranged in stripes are orthogonal to each other. The light emitting layer is sandwiched between the intersections. Therefore, the pixel corresponding to the intersection between the selected anode (to which voltage is applied) and the selected cathode is turned on.

2A to 2C are top views of the pixel portion before sealing, and a cross section taken along a chain line AA ′ in FIGS. 2A to 2C. The figure is shown in FIG.

An insulating layer 402 is formed over the substrate 401 as a base insulating layer. Note that the base insulating layer is not particularly required if it is not necessary. A plurality of first electrodes 403 are arranged in stripes at regular intervals over the insulating layer 402 (FIG. 2A).

Further, a partition 404 having an opening corresponding to each pixel is provided over the first electrode 403, and the partition 404 having the opening has an insulating material (photosensitive or non-photosensitive organic material (polyimide, acrylic, Polyamide, polyimide amide, resist or benzocyclobutene), or SOG film (for example, an SiOx film containing an alkyl group)). Note that the opening 405 corresponding to each pixel serves as a light-emitting region (FIG. 2B).

A plurality of reverse-tapered partition walls 406 that are parallel to each other and intersect with the first electrode 403 are provided over the partition walls 404 having openings (FIG. 2C). The reverse-tapered partition 406 is formed by using a positive photosensitive resin in which an unexposed portion remains as a pattern according to a photolithography method, and adjusting the exposure amount or development time so that the lower portion of the pattern is etched more. .

After a reverse-tapered partition 406 is formed as shown in FIG. 2C, an EL layer 407 and a second electrode 408 are sequentially formed as shown in FIG. The combined height of the partition wall 404 having an opening and the reverse-tapered partition wall 406 is set to be larger than the film thickness of the EL layer 407 and the second electrode 408, and thus is shown in FIG. Thus, an EL layer 407 separated into a plurality of regions and a second electrode 408 are formed. Note that the plurality of regions separated from each other are electrically independent.

The second electrode 408 is a striped electrode parallel to each other and extending in a direction intersecting with the first electrode 403. Note that part of the conductive layer for forming the EL layer 407 and the second electrode 408 is formed over the inverse-tapered partition wall 406, but the EL layer 407 and the second electrode 408 are separated from each other. .

Note that one of the first electrode 403 and the second electrode 408 in this embodiment may be an anode and the other may be a cathode. Note that the stacked structure included in the EL layer 407 may be adjusted as appropriate depending on the polarity of the electrode.

Further, if necessary, a sealing material such as a sealing can or a glass substrate is bonded to the substrate 401 with an adhesive such as a sealing material and sealed so that the light emitting element is disposed in a sealed space. Also good. Thereby, deterioration of the light emitting element can be prevented. Note that the sealed space may be filled with a filler or a dry inert gas. Further, a desiccant or the like may be sealed between the substrate and the sealing material in order to prevent the light emitting element from being deteriorated due to moisture or the like. A trace amount of water is removed by the desiccant, and it is sufficiently dried. Note that as the desiccant, a substance that absorbs moisture by chemical adsorption, such as an oxide of an alkaline earth metal such as calcium oxide or barium oxide, can be used. As another desiccant, a substance that adsorbs moisture by physical adsorption, such as zeolite or silica gel, may be used.

Next, FIG. 3 is a top view in the case where an FPC or the like is mounted on the passive matrix light-emitting device illustrated in FIGS. 2A to 2D.

In FIG. 3, the pixel portions constituting the image display intersect such that the scanning line group and the data line group are orthogonal to each other.

Here, the first electrode 403 in FIG. 2 corresponds to the scan line 503 in FIG. 3, the second electrode 408 in FIG. 2 corresponds to the data line 508 in FIG. It corresponds to the partition 506. The EL layer 407 in FIG. 2 is sandwiched between the data line 508 and the scanning line 503, and an intersection indicated by a region 505 corresponds to one pixel.

Note that the scanning line 503 is electrically connected to the connection wiring 509 at a wiring end, and the connection wiring 509 is connected to the FPC 511 b through the input terminal 510. The data line is connected to the FPC 511a through the input terminal 512.

If necessary, an optical film such as a polarizing plate, a circular polarizing plate (including an elliptical polarizing plate), a retardation plate (λ / 4 plate, λ / 2 plate), a color filter, or the like may be appropriately provided on the exit surface. Good. Further, an antireflection film may be provided on the polarizing plate or the circularly polarizing plate. For example, anti-glare treatment can be performed that diffuses reflected light due to surface irregularities and reduces reflection.

Note that FIG. 3 illustrates an example in which the driver circuit is not provided over the substrate 501, but an IC chip including the driver circuit may be mounted over the substrate 501.

When an IC chip is mounted, a data line side IC and a scanning line side IC in which a driving circuit for transmitting each signal to the pixel portion is formed in a peripheral (outside) region of the pixel portion by a COG method. Implement. You may mount using TCP and a wire bonding system as mounting techniques other than a COG system. TCP is an IC mounted on a TAB tape, and the IC is mounted by connecting the TAB tape to a wiring on an element formation substrate. The data line side IC and the scanning line side IC may be those using a silicon substrate, or may be a glass substrate, a quartz substrate, or a plastic substrate formed with a drive circuit using an FET.

Next, an example of an active matrix light-emitting device is described with reference to FIGS. 4A is a top view illustrating the light-emitting device, and FIG. 4B is a cross-sectional view taken along the chain line A-A ′ in FIG. 4A. An active matrix light-emitting device according to this embodiment includes a pixel portion 602 provided over an element substrate 601, a driver circuit portion (source side driver circuit) 603, a driver circuit portion (gate side driver circuit) 604, Have. The pixel portion 602, the driver circuit portion 603, and the driver circuit portion 604 are sealed between the element substrate 601 and the sealing substrate 606 with a sealant 605.

Further, on the element substrate 601, external input terminals for transmitting a signal (eg, a video signal, a clock signal, a start signal, or a reset signal) and a potential from the outside to the driver circuit portion 603 and the driver circuit portion 604 are provided. A lead wiring 607 for connection is provided. In this example, an FPC (flexible printed circuit) 608 is provided as an external input terminal. Although only the FPC is shown here, a printed wiring board (PWB) may be attached to the FPC. The light-emitting device in this specification includes not only a light-emitting device body but also a state in which an FPC or a PWB is attached thereto.

Next, a cross-sectional structure is described with reference to FIG. A driver circuit portion and a pixel portion are formed over the element substrate 601, but here, a driver circuit portion 603 which is a source side driver circuit and a pixel portion 602 are shown.

The drive circuit portion 603 shows an example in which a CMOS circuit in which an n-channel FET 609 and a p-channel FET 610 are combined is formed. Note that the circuit forming the driver circuit portion may be formed of various CMOS circuits, PMOS circuits, or NMOS circuits. In this embodiment mode, a driver integrated type in which a driver circuit is formed over a substrate is shown; however, this is not necessarily required, and the driver circuit can be formed outside the substrate.

The pixel portion 602 is formed by a plurality of pixels including a switching FET 611 and a current control FET 612 and an anode 613 electrically connected to the wiring (source electrode or drain electrode) of the current control FET 612. Note that an insulator 614 is formed so as to cover an end portion of the anode 613. Here, it is formed by using a positive photosensitive acrylic resin.

In addition, in order to improve the coverage of the film formed to be stacked on the upper layer, it is preferable that a curved surface having a curvature be formed at the upper end portion or the lower end portion of the insulator 614. For example, in the case where a positive photosensitive acrylic resin is used as a material of the insulator 614, it is preferable that the upper end portion of the insulator 614 has a curved surface having a curvature radius (0.2 μm to 3 μm). Further, as the insulator 614, either a negative type that becomes insoluble in an etchant by photosensitive light or a positive type that becomes soluble in an etchant by light can be used. For example, both silicon oxide and silicon oxynitride can be used.

An EL layer 615 and a cathode 616 are stacked over the anode 613. In addition, the anode 613 is an ITO film, and the wiring of the current control FET 612 connected to the anode 613 is a laminated film of a titanium nitride film and a film containing aluminum as a main component, or a titanium nitride film, a film containing aluminum as a main component, When a laminated film with a titanium nitride film is applied, resistance as a wiring is low and good ohmic contact with the ITO film can be obtained. Although not shown here, the cathode 616 is electrically connected to the FPC 608 which is an external input terminal.

Note that at least a light-emitting layer is provided in the EL layer 615, and a hole injection layer, a hole transport layer, an electron transport layer, or an electron injection layer is provided as appropriate in addition to the light-emitting layer. A light emitting element 617 is formed with a stacked structure of an anode 613, an EL layer 615, and a cathode 616.

In the cross-sectional view illustrated in FIG. 4B, only one light-emitting element 617 is illustrated; however, in the pixel portion 602, a plurality of light-emitting elements are arranged in a matrix. In the pixel portion 602, light emitting elements capable of emitting three types (R, G, and B) of light emission can be selectively formed, so that a light emitting device capable of full color display can be formed. Alternatively, a light emitting device capable of full color display may be obtained by combining with a color filter.

Further, the sealing substrate 606 is bonded to the element substrate 601 with the sealant 605, whereby the light-emitting element 617 is provided in the space 618 surrounded by the element substrate 601, the sealing substrate 606, and the sealant 605. Yes. Note that the space 618 includes a structure filled with a sealant 605 in addition to a case where the space 618 is filled with an inert gas (such as nitrogen or argon).

Note that an epoxy-based resin is preferably used for the sealant 605. Moreover, it is desirable that these materials are materials that do not transmit moisture and oxygen as much as possible. In addition to a glass substrate and a quartz substrate, a plastic substrate made of FRP (Fiberglass-Reinforced Plastics), PVF (polyvinyl fluoride), polyester, acrylic, or the like can be used as a material for the sealing substrate 606.

As described above, an active matrix light-emitting device can be obtained.

Note that the structure described in this embodiment can be combined with any of the structures described in other embodiments as appropriate.

(Embodiment 6)
In this embodiment, examples of various electronic devices and lighting devices completed using a light-emitting device which is one embodiment to which the present invention is applied will be described with reference to FIGS.

As electronic devices to which the light-emitting device is applied, for example, a television set (also referred to as a television or a television receiver), a monitor for a computer, a digital camera, a digital video camera, a digital photo frame, a mobile phone (a mobile phone, a mobile phone) Also referred to as a telephone device), portable game machines, portable information terminals, sound reproduction devices, large game machines such as pachinko machines, and the like.

By manufacturing a light-emitting element using the organometallic complex of one embodiment of the present invention over a flexible substrate, an electronic device or a lighting device including a light-emitting portion having a curved surface can be realized.

In addition, a pair of electrodes included in the light-emitting element using the organometallic complex of one embodiment of the present invention is formed using a material having a property of transmitting visible light, so that an electronic device or a lighting device having a see-through light-emitting portion Can be realized.

The light-emitting device to which one embodiment of the present invention is applied can also be applied to automobile lighting. For example, lighting can be provided on a dashboard, a windshield, a ceiling, or the like.

Specific examples of these electronic devices and lighting fixtures are shown in FIGS.

FIG. 5A illustrates an example of a television device. In the television device 7100, a display portion 7103 is incorporated in a housing 7101. Images can be displayed on the display portion 7103, and a light-emitting device can be used for the display portion 7103. Here, a structure in which the housing 7101 is supported by a stand 7105 is shown.

The television device 7100 can be operated with an operation switch included in the housing 7101 or a separate remote controller 7110. Channels and volume can be operated with an operation key 7109 provided in the remote controller 7110, and an image displayed on the display portion 7103 can be operated. The remote controller 7110 may be provided with a display portion 7107 for displaying information output from the remote controller 7110.

Note that the television device 7100 is provided with a receiver, a modem, and the like. General TV broadcasts can be received by a receiver, and connected to a wired or wireless communication network via a modem, so that it can be unidirectional (sender to receiver) or bidirectional (sender and receiver). It is also possible to perform information communication between each other or between recipients).

FIG. 5B illustrates a computer, which includes a main body 7201, a housing 7202, a display portion 7203, a keyboard 7204, an external connection port 7205, a pointing device 7206, and the like. Note that the computer is manufactured by using the light-emitting device for the display portion 7203.

FIG. 5C illustrates a portable game machine, which includes two housings, a housing 7301 and a housing 7302, which are connected with a joint portion 7303 so that the portable game machine can be opened or folded. A display portion 7304 is incorporated in the housing 7301 and a display portion 7305 is incorporated in the housing 7302. In addition, the portable game machine shown in FIG. 5C includes a speaker portion 7306, a recording medium insertion portion 7307, an LED lamp 7308, input means (operation keys 7309, a connection terminal 7310, a sensor 7311 (force, displacement, position). , Speed, acceleration, angular velocity, number of revolutions, distance, light, liquid, magnetism, temperature, chemical, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, smell or infrared A microphone 7312) and the like. Needless to say, the structure of the portable game machine is not limited to the above, and it is sufficient that a light-emitting device is used for at least one of the display portion 7304 and the display portion 7305, or other accessory equipment is provided as appropriate. can do. The portable game machine shown in FIG. 5C shares the information by reading a program or data recorded in a recording medium and displaying the program or data on a display unit, or by performing wireless communication with another portable game machine. It has a function. Note that the function of the portable game machine illustrated in FIG. 5C is not limited to this, and the portable game machine can have a variety of functions.

FIG. 5D illustrates an example of a mobile phone. A mobile phone 7400 is provided with a display portion 7402 incorporated in a housing 7401, operation buttons 7403, an external connection port 7404, a speaker 7405, a microphone 7406, and the like. Note that the cellular phone 7400 is manufactured using the light-emitting device for the display portion 7402.

A cellular phone 7400 illustrated in FIG. 5D can input information by touching the display portion 7402 with a finger or the like. In addition, operations such as making a call or creating a mail can be performed by touching the display portion 7402 with a finger or the like.

There are mainly three screen modes of the display portion 7402. The first mode is a display mode mainly for displaying an image. The first is a display mode mainly for displaying images, and the second is an input mode mainly for inputting information such as characters. The third is a display + input mode in which the display mode and the input mode are mixed.

For example, when making a call or creating a mail, the display portion 7402 may be set to a character input mode mainly for inputting characters, and an operation for inputting characters displayed on the screen may be performed. In this case, it is preferable to display a keyboard or number buttons on most of the screen of the display portion 7402.

In addition, by providing a detection device having a sensor for detecting inclination, such as a gyroscope or an acceleration sensor, in the mobile phone 7400, the orientation (vertical or horizontal) of the mobile phone 7400 is determined, and the screen display of the display portion 7402 is displayed. Can be switched automatically.

Further, the screen mode is switched by touching the display portion 7402 or operating the operation button 7403 of the housing 7401. Further, switching can be performed depending on the type of image displayed on the display portion 7402. For example, if the image signal to be displayed on the display unit is moving image data, the mode is switched to the display mode, and if it is text data, the mode is switched to the input mode.

Further, in the input mode, when a signal detected by the optical sensor of the display unit 7402 is detected and there is no input by a touch operation of the display unit 7402 for a certain period, the screen mode is switched from the input mode to the display mode. You may control.

The display portion 7402 can function as an image sensor. For example, personal authentication can be performed by touching the display portion 7402 with a palm or a finger and capturing an image of a palm print, a fingerprint, or the like. In addition, if a backlight that emits near-infrared light or a sensing light source that emits near-infrared light is used for the display portion, finger veins, palm veins, and the like can be imaged.

As described above, by using the light-emitting device of one embodiment of the present invention, the display portion of the electronic device can achieve high light emission efficiency. In addition, by applying one embodiment of the present invention, a highly reliable electronic device can be provided. In addition, an electronic device with low power consumption can be manufactured by applying one embodiment of the present invention.

FIG. 5E illustrates a table lamp, which includes a lighting unit 7501, an umbrella 7502, a variable arm 7503, a column 7504, a base 7505, and a power source 7506. Note that the desk lamp is manufactured by using a light-emitting device for the lighting portion 7501. Note that the lighting fixture includes a ceiling-fixed lighting fixture or a wall-mounted lighting fixture.

FIG. 6A illustrates an example in which the light-emitting device is used as an indoor lighting device 801. Since the light-emitting device can have a large area, the light-emitting device can be used as a large-area lighting device. In addition, it can also be used as a roll-type lighting device 802. Note that as illustrated in FIG. 6A, the desk lamp 803 described with reference to FIG. 5E may be used in a room provided with an indoor lighting device 801.

FIG. 6B illustrates another example of a lighting device. A desk lamp illustrated in FIG. 6B includes a lighting portion 9501, a support column 9503, a support base 9505, and the like. The lighting portion 9501 includes the organometallic complex of one embodiment of the present invention. In this manner, by manufacturing the light-emitting element of one embodiment of the present invention over a flexible substrate, a lighting device having a curved surface or a lighting device having a lighting portion that bends flexibly can be obtained. Thus, by using a flexible light-emitting device as a lighting device, not only the degree of freedom in designing the lighting device is improved, but also the lighting device is installed in a place having a curved surface such as a car ceiling or a dashboard, for example. It becomes possible to do.

FIG. 7 shows an example of another lighting device. As described above, by using one embodiment of the present invention, a lighting device having a curved surface can be manufactured. In addition, since the organometallic complex of one embodiment of the present invention emits yellow to orange light, a yellow lighting device or an orange lighting device can be provided. For example, one embodiment of the present invention can be applied to the lighting device 9900 in the tunnel illustrated in FIG. By applying one embodiment of the present invention, a lighting device with high light emission efficiency and high energy efficiency can be realized, and yellow to orange light emission has high visibility, so that an accident can be suppressed. In addition, since the lighting device to which one embodiment of the present invention is applied is a surface light source, the directivity can be suppressed from becoming excessively strong, and the cause of an accident can be reduced.

Further, the above-described yellow lighting device can be applied to a yellow room or the like. By using the lighting device to which one embodiment of the present invention is applied for lighting in a yellow room, a shadow is hardly generated and a favorable working environment can be provided.

As described above, by using the light-emitting device of one embodiment of the present invention, the lighting device can achieve high light emission efficiency. In addition, by applying one embodiment of the present invention, a highly reliable lighting device can be provided. Further, by applying one embodiment of the present invention, a lighting device with low power consumption can be manufactured.

As described above, an electronic device or a lighting fixture can be obtained by using the light-emitting device. The application range of the light-emitting device is extremely wide and can be applied to electronic devices in various fields.

Note that the structure described in this embodiment can be combined with any of the structures described in other embodiments as appropriate.

<< Synthesis Example 1 >>
In Example 1, an organometallic iridium complex which is one embodiment of the present invention represented by the structural formula (100) of Embodiment 1, tris {2- [6- (2-methylpropyl) -4-pyrimidinyl- A method for synthesizing κN3] phenyl-κC} iridium (III) (abbreviation: [Ir (iBupppm) ₃ ]) will be described. Note that a structure of [Ir (iBupppm) ₃ ] (abbreviation) is shown below.

<Step 1: Synthesis of 5-methyl-1-phenylhexane-1,3-dione>
First, 55 mL of N, N′-dimethylformamide (abbreviation: DMF) and 9.0 g of potassium-t-butoxide (abbreviation: tBuOK) were placed in a 200 mL three-neck flask, the inside of the container was purged with nitrogen, and the mixture was heated to 50 ° C. Thereafter, 4.0 g of 4-methyl-2-pentanone, 9.0 g of ethyl benzoate dissolved in 5 mL of DMF (abbreviation) was added, and the mixture was heated at 50 ° C. for 2 hours. 20% sulfuric acid and water were added to the obtained mixture, and suction filtration was performed. Water was added to the filtrate, and the organic layer was extracted with dichloromethane, washed with saturated brine, magnesium sulfate was added, and the mixture was naturally filtered. The solvent of the filtrate was distilled off, and purification by silica gel column chromatography using dichloromethane: hexane = 1: 2 as a developing solvent gave 6.8 g of the desired product (yield: 83%, yellow oil) Obtained. The synthesis scheme of Step 1 is shown in (A-1) below.

<Step 2: Synthesis of 4- (2-methylpropyl) -6-phenylpyrimidine (abbreviation: HiBupppm)>
Next, 6.8 g of 5-methyl-1-phenylhexane-1,3-dione synthesized in Step 1 and 15 g of formamide were placed in a reaction vessel, and irradiated with microwaves (2.45 GHz, 400 W) for 4 hours. The obtained solution was put into 200 mL of 0.1 M sodium hydroxide aqueous solution, stirred for 30 minutes, and the organic layer was extracted with dichloromethane. The extract was washed with water, saturated aqueous sodium hydrogen carbonate solution and saturated brine, magnesium sulfate was added, and the mixture was naturally filtered. The solvent of the filtrate was distilled off, and purification by silica gel column chromatography using dichloromethane as a developing solvent gave 2.7 g of the desired product (yield: 38%, pale yellow oil). Note that a microwave synthesizer (MicroSYNCH manufactured by MILESTONE) was used for microwave irradiation. The synthesis scheme of Step 2 is shown in (A-2) below.

<Step 3: Di-μ-chloro-tetrakis {2- [6- (2-methylpropyl) -4-pyrimidinyl-κN3] phenyl-κC} diiridium (III) (abbreviation: [Ir (iBupppm) ₂ Cl] ₂ ) Synthesis>
Place 1.5 g of HiBupppm (abbreviation) synthesized in Step 2 above, 1.1 g of iridium (III) chloride hydrate, 30 mL of 2-ethoxyethanol, and 10 mL of water into a 100 mL round bottom flask equipped with a reflux tube. Was replaced with argon, and was irradiated with microwaves (2.45 GHz, 100 W) for 2 hours. The solvent of the obtained reaction solution was distilled off and suction filtered with methanol to obtain 1.3 g (yield: 71%, dark brown powder solid) of the target product. For microwave irradiation, a microwave synthesizer (Discover manufactured by CEM) was used. The synthesis scheme of Step 3 is shown in (A-3) below.

<Step 4: Synthesis of tris {2- [6- (2-methylpropyl) -4-pyrimidinyl-κN3] phenyl-κC} iridium (III) (abbreviation: [Ir (iBupppm) ₃ ])>
1.2 g of [Ir (iBupppm) ₂ Cl] ₂ (abbreviation), 0.94 g of HiBupppm (abbreviation), 1.2 g of potassium carbonate, and 11 g of phenol synthesized in Step 3 above are placed in a 200 mL three-necked flask equipped with a reflux tube. The flask was purged with argon and heated at 185 ° C. for 9 hours. The obtained reaction product was ultrasonically washed with methanol and suction filtered. The residue was dissolved in dichloromethane and purified by silica gel column chromatography using ethyl acetate: hexane = 1: 2 as a developing solvent. The solvent of the obtained solution was distilled off, and recrystallization was performed using a mixed solvent of dichloromethane and methanol, so that an organometallic complex [Ir (iBupppm) ₃ ] (abbreviation) of one embodiment of the present invention was obtained ( Yield: 68%, orange powder solid). Sublimation purification of 0.73 g of the obtained orange powder solid was performed by a train sublimation method. As the sublimation purification conditions, the solid was heated at 250 ° C. while flowing a pressure of 2.5 Pa and argon gas at a flow rate of 15 mL / min. After purification by sublimation, the target orange solid was obtained in a yield of 66% (UPLC purity of 99.9 area% or more). The synthesis scheme of Step 4 is shown in (A-4) below.

In addition, the analysis result by the nuclear magnetic resonance spectroscopy (< ¹ > H-NMR) of the orange powder obtained at the said step 4 is shown below. A ¹ H-NMR chart is shown in FIG. From this result, it was confirmed in Synthesis Example 1 that the organometallic complex [Ir (iBupppm) ₃ ] (abbreviation) of one embodiment of the present invention represented by the above structural formula (100) was obtained.

¹ H NMR data of the organometallic complex [Ir (iBupppm) ₃ ] (abbreviation) is shown below.
¹ H-NMR. δ (CDCl ₃ ): 0.962-0.976 (d, 18H), 2.09-2.17 (m, 3H), 2.65-2.66 (dd, 6H), 6.80-6 .82 (dd, 3H), 6.89-6.92 (dt, 3H), 6.94-6.97 (dt, 3H), 7.58 (s, 3H), 7.73-7.75 (D, 3H), 8.18 (s, 3H).

Next, an ultraviolet-visible absorption spectrum (hereinafter, simply referred to as “absorption spectrum”) and an emission spectrum of [Ir (iBupppm) ₃ ] (abbreviation) in a dichloromethane solution were measured. For the measurement of the absorption spectrum, an ultraviolet-visible spectrophotometer (model V550 manufactured by JASCO Corporation) was used, and a dichloromethane solution (0.081 mmol / L) was put in a quartz cell and measured at room temperature. The emission spectrum was measured using a fluorometer (FS920, Hamamatsu Photonics Co., Ltd.), and the degassed dichloromethane solution (0.081 mmol / L) was placed in a quartz cell and measured at room temperature. The measurement results of the obtained absorption spectrum and emission spectrum are shown in FIG. The horizontal axis represents wavelength, and the vertical axis represents absorption intensity and emission intensity. In FIG. 9, two solid lines are shown. The thin line represents the absorption spectrum, and the thick line represents the emission spectrum. The absorption spectrum shown in FIG. 9 shows the result of subtracting the absorption spectrum measured by putting only dichloromethane in the quartz cell from the absorption spectrum measured by putting the dichloromethane solution (0.081 mmol / L) in the quartz cell.

As shown in FIG. 9, the organometallic complex [Ir (iBupppm) ₃ ] (abbreviation) of one embodiment of the present invention has an emission peak at 534 nm, and yellow-green emission was observed from the dichloromethane solution.

Next, mass (MS) analysis was performed on [Ir (iBupppm) ₃ ] (abbreviation) obtained in this example by liquid chromatography mass spectrometry (abbreviation: LC / MS analysis).

In LC / MS analysis, LC (liquid chromatography) separation was performed by Acquity UPLC manufactured by Waters, and MS analysis (mass spectrometry) was performed by Xevo G2 Tof MS manufactured by Waters. The column used for the LC separation was Acquity UPLC BEH C8 (2.1 × 100 mm 1.7 μm), and the column temperature was 40 ° C. As the mobile phase, mobile phase A was acetonitrile and mobile phase B was 0.1% formic acid aqueous solution. The sample was prepared by dissolving [Ir (iBupppm) ₃ ] (abbreviation) of any concentration in chloroform and diluting with acetonitrile, and the injection volume was 5.0 μL.

In MS analysis, ionization by electrospray ionization (ElectroSpray Ionization (abbreviation: ESI)) was performed. At this time, the capillary voltage was 3.0 kV, the sample cone voltage was 30 V, and the detection was performed in the positive mode. The component of m / z = 827.34 ionized under the above conditions was collided with argon gas in the collision chamber (collision cell) and dissociated into product ions. The energy (collision energy) for collision with argon was 50 eV. The mass range to be measured was m / z = 100 to 1200. FIG. 10 shows the result of detecting dissociated product ions by time-of-flight (TOF) type MS.

From the results of FIG. 10, it was found that [Ir (iBupppm) ₃ ] (abbreviation) detects product ions mainly in the vicinity of m / z = 611, 401, 213, and 170. Incidentally, the results shown in FIG. 10, [Ir _(iBuppm) 3] Since shows the characteristic results from a (abbreviation), contained in the mixture [Ir _(iBuppm) 3] (abbreviation) It can be said that this is important data for identification.

Note that the product ion in the vicinity of m / z = 611 is estimated to be a cation in the state where HiBupppm (abbreviation) in [Ir (iBupppm) ₃ ] (abbreviation) is released, and the product ion in the vicinity of m / z = 401 is [ In Ir (iBupppm) ₃ ] (abbreviation), two cations of HNpppm (abbreviation) are estimated to be released, and the product ion near m / z = 213 is estimated to be a cation of HiBupppm (abbreviation), and HiBupppm (abbreviation). ) Is included in [Ir (iBupppm) ₃ ] (abbreviation). Furthermore, the product ion near m / z = 170 is presumed to be a cation having a propyl group removed from the product ion near m / z = 213, and [Ir (iBupppm) ₃ ] (abbreviation) contains an alkyl chain. It is suggested that it is.

<< Synthesis Example 2 >>
In Synthesis Example 2, an organometallic complex which is one embodiment of the present invention represented by Structural Formula (101) of Embodiment 1, Tris {2- [6- (2,2′-dimethylpropyl) -4-pyrimidinyl] A specific example of the synthesis of —κN3] phenyl-κC} iridium (III) (abbreviation: [Ir (Npppm) ₃ ]) is specifically illustrated. Note that the structure of [Ir (Npppm) ₃ ] (abbreviation) is shown below.

<Step 1: Synthesis of 5,5′-dimethyl-1-phenylhexane-1,3-dione>
First, 14 g of potassium-t-butoxide (abbreviation: KOtBu) was placed in a 200 mL three-necked flask equipped with a reflux tube, the inside of the flask was purged with nitrogen, and 83 mL of N, N′-dimethylformamide (abbreviation: DMF) was added. Heated to ° C. Then, 6.85 g of 4,4′-dimethyl-2-pentanone dissolved in 13.5 g of ethyl benzoate and 7.5 mL of DMF (abbreviation) was added and heated for 1.5 hours. A 20% aqueous sulfuric acid solution and water were added to the resulting solution, and the organic layer was extracted with dichloromethane. The extract was washed with saturated brine, magnesium sulfate was added, and the mixture was naturally filtered. The filtrate was evaporated and purified by flash column chromatography using hexane as a developing solvent to obtain 11 g of the desired product (yield: 84%, pale yellow oil). The synthesis scheme of Step 1 is shown in (B-1) below.

<Step 2: Synthesis of 4- (2,2′-dimethylpropyl) -6-phenylpyrimidine (abbreviation: HNpppm)>
Next, 11 g of 5,5′-dimethyl-1-phenylhexane-1,3-dione synthesized in Step 1 above and 23 g of formamide were placed in a reaction vessel, and microwaves (2.45 GHz, 400 W) were applied in a sealed system for 2 times. Irradiated for hours. To the resulting mixture, 200 mL of sodium hydroxide was added and stirred for 30 minutes, and the organic layer was extracted with dichloromethane. The extract was washed with saturated brine, magnesium sulfate was added, and the mixture was naturally filtered. The filtrate was evaporated, and purified by silica gel column chromatography using ethyl acetate: hexane = 1: 5 as a developing solvent to obtain 3.2 g of the desired product (yield: 29%, pale yellow oily substance). ) Note that a microwave synthesizer (MicroSYNCH manufactured by MILESTONE) was used for microwave irradiation. The synthesis scheme of Step 2 is shown in (B-2) below.

<Step 3: Di-μ-chloro-tetrakis {2- [6- (2,2′-dimethylpropyl) -4-pyrimidinyl-κN3] phenyl-κC} diiridium (III) (abbreviation: [Ir (Npppm) _{2 Cl] 2)} synthesis of>
HNpppm (abbreviation) 2.1 g synthesized in Step 2 above, 1.5 g of iridium (III) chloride hydrate, 30 mL of 2-ethoxyethanol, and 10 mL of water were placed in a 100 mL round bottom flask equipped with a reflux tube. Was replaced with argon, and irradiated with microwaves (2.45 GHz, 100 W) for 3.5 hours. The solvent of the obtained mixture was distilled off, and suction filtration with methanol was performed to obtain 2.6 g of the desired product (yield: 74%, dark green solid). The synthesis scheme of Step 3 is shown in (B-3) below.

<Step 4: Synthesis of tris {2- [6- (2,2′-dimethylpropyl) -4-pyrimidinyl-κN3] phenyl-κC} iridium (III) (abbreviation: [Ir (Npppm) ₃ ])>
[Ir (Npppm) ₂ Cl] ₂ (abbreviation) 2.6 g, HNpppm (abbreviation) 1.9 g, sodium carbonate 1.9 g, and phenol 10 g synthesized in Step 3 above were placed in a 200 mL three-necked flask equipped with a reflux tube. And heated at 180 ° C. for 7 hours. The obtained mixture was ultrasonically washed with methanol and suction filtered. The solvent of the filtrate was distilled off, the organic layer was extracted with dichloromethane, washed with saturated brine, added with magnesium sulfate, and naturally filtered. The solvent of the filtrate was distilled off and the residue was purified by flash column chromatography using ethyl acetate: hexane = 1: 5 as a developing solvent. The solvent of the obtained solution was distilled off, and recrystallization was performed with methanol and dichloromethane, whereby an organometallic complex [Ir (Npppm) ₃ ] (abbreviation) of one embodiment of the present invention was obtained (yield: 48). %, Orange powder solid). Sublimation purification of 1.3 g of the obtained orange powder solid was performed by a train sublimation method. As the sublimation purification conditions, the solid was heated between 250 ° C. and 260 ° C. while a pressure of 2.4 Pa and argon gas were flowed at a flow rate of 5.0 mL / min. After purification by sublimation, the target orange solid was obtained with a yield of 85% (UPLC purity 96.9 area%). The synthesis scheme of Step 4 is shown in (B-4) below.

In addition, the analysis result by the nuclear magnetic resonance spectroscopy (< ¹ > H-NMR) of the orange powder obtained at the said step 4 is shown below. Further, the ¹ H-NMR chart is shown in FIG. From this result, it was confirmed in Synthesis Example 2 that the organometallic complex [Ir (Npppm) ₃ ] (abbreviation) of one embodiment of the present invention represented by the above structural formula (101) was obtained.

¹ H NMR data of the organometallic complex [Ir (Npppm) ₃ ] (abbreviation) is shown below.
¹ H-NMR. δ (CDCl ₃ ): 1.00 (s, 18H), 2.66 (s, 6H), 6.79-6.80 (dd, 3H), 6.88-6.96 (dm, 6H), 7.56 (ds, 3H), 7.72-7.74 (dd, 3H), 8.19 (ds, 3H).

Next, an ultraviolet-visible absorption spectrum (hereinafter, simply referred to as “absorption spectrum”) and an emission spectrum of [Ir (Npppm) ₃ ] (abbreviation) in a dichloromethane solution were measured. For the measurement of the absorption spectrum, an ultraviolet-visible spectrophotometer (model V550 manufactured by JASCO Corporation) was used, and a dichloromethane solution (0.080 mmol / L) was placed in a quartz cell and measured at room temperature. The emission spectrum was measured using a fluorometer (FS920 manufactured by Hamamatsu Photonics Co., Ltd.), and the degassed dichloromethane solution (0.080 mmol / L) was placed in a quartz cell and measured at room temperature. The measurement results of the obtained absorption spectrum and emission spectrum are shown in FIG. The horizontal axis represents wavelength, and the vertical axis represents absorption intensity and emission intensity. In FIG. 12, two solid lines are shown. A thin line represents the absorption spectrum, and a thick line represents the emission spectrum. The absorption spectrum shown in FIG. 12 shows the result of subtracting the absorption spectrum measured by putting only dichloromethane in the quartz cell from the absorption spectrum measured by putting the dichloromethane solution (0.080 mmol / L) in the quartz cell.

As shown in FIG. 12, the organometallic complex [Ir (Npppm) ₃ ] (abbreviation) of one embodiment of the present invention has an emission peak at 535 nm, and yellow-green emission was observed from the dichloromethane solution.

Next, [Ir (Npppm) ₃ ] (abbreviation) obtained in this example was subjected to mass (MS) analysis by liquid chromatograph mass spectrometry (abbreviation: LC / MS analysis).

In LC / MS analysis, LC (liquid chromatography) separation was performed by Acquity UPLC manufactured by Waters, and MS analysis (mass spectrometry) was performed by Xevo G2 Tof MS manufactured by Waters. The column used for the LC separation was Acquity UPLC BEH C8 (2.1 × 100 mm 1.7 μm), and the column temperature was 40 ° C. As the mobile phase, mobile phase A was acetonitrile and mobile phase B was 0.1% formic acid aqueous solution. The sample was prepared by dissolving [Ir (Npppm) ₃ ] (abbreviation) of any concentration in chloroform and diluting with acetonitrile, and the injection volume was 5.0 μL.

In MS analysis, ionization by electrospray ionization (ElectroSpray Ionization (abbreviation: ESI)) was performed. At this time, the capillary voltage was 3.0 kV, the sample cone voltage was 30 V, and the detection was performed in the positive mode. The component of m / z = 869.39 ionized under the above conditions was collided with argon gas in the collision chamber (collision cell) and dissociated into product ions. The energy (collision energy) for collision with argon was 50 eV. The mass range to be measured was m / z = 100 to 1200. FIG. 13 shows a result of detecting dissociated product ions by time-of-flight (TOF) type MS.

From the results shown in FIG. 13, it was confirmed that [Ir (Npppm) ₃ ] (abbreviation) mainly detects product ions in the vicinity of m / z = 643, 415, 401. Incidentally, the results shown in FIG. 13, [Ir _(Npppm) 3] Since shows the characteristic results from a (abbreviation), contained in the mixture [Ir _(Npppm) 3] (abbreviation) It can be said that this is important data for identification.

Note that the product ion in the vicinity of m / z = 643 is estimated to be a cation in a state where HNpppm (abbreviation) in [Ir (Npppm) ₃ ] (abbreviation) is released, and the product ion in the vicinity of m / z = 415 is [ It is estimated that two HNpppm (abbreviations) in Ir (Npppm) ₃ ] (abbreviation) are cations separated, suggesting that [Ir (Npppm) ₃ ] (abbreviation) contains HNpppm (abbreviation). To do. Further, the product ion near m / z = 401 is presumed to be a cation having a methyl group eliminated from the product ion near m / z = 415, and an alkyl chain is present in [Ir (Npppm) ₃ ] (abbreviation). It is suggested that it is included.

<< Synthesis Example 3 >>
In this synthesis example 3, the organometallic complex of one embodiment of the present invention represented by the structural formula (102) of Embodiment 1, tris {5-methoxy-2- [6- (2-methylpropyl) -4-pyrimidinyl] A specific example of the synthesis of —κN3] phenyl-κC} iridium (III) (abbreviation: [Ir (iBumoppm) ₃ ]) is specifically illustrated. Note that the structure of [Ir (iBumoppm) ₃ ] (abbreviation) is shown below.

<Step 1; Synthesis of 4-chloro-6- (2-methylpropyl) pyrimidine>
First, 1.02 g of 4,6-dichloropyrimidine, 0.14 g of tris (2,4-pentanedionato) iron (III) (abbreviation: Fe (acac) ₃ ), 67 mL of dry THF, 1-methyl-2-pyrrolidone (abbreviation) : NMP) 5.6 mL was placed in a 200 mL three-necked flask, and the atmosphere in the flask was replaced with nitrogen. After cooling the flask with ice, 6.7 mL of isobutyl magnesium bromide (1M THF solution) was added, and the mixture was stirred at room temperature for 20 and a half hours. Thereafter, 1N hydrochloric acid was added, and the organic layer was extracted with ethyl acetate. The obtained extract was washed with a saturated aqueous sodium hydrogen carbonate solution and saturated brine, and dried over magnesium sulfate. The solution after drying was filtered. After the solvent of this solution was distilled off, the obtained residue was purified by flash column chromatography using dichloromethane: ethyl acetate = 10: 1 as a developing solvent to obtain the desired product (yellow oil, yield 65%). ). The synthesis scheme of Step 1 is shown in (C-1) below.

<Step 2; Synthesis of 4- (4-methoxyphenyl) 6- (2-methylpropyl) pyrimidine (abbreviation: HiBummoppm)>
Next, 2.06 g of 4-chloro-6- (2-methylpropyl) pyrimidine obtained in Step 1 above, 2.74 g of 4-methoxyphenylboronic acid, 1.85 g of sodium carbonate, bis (triphenylphosphine) palladium ( II) 0.098 g of dichloride (abbreviation: Pd (PPh ₃ ) ₂ Cl ₂ ), 20 mL of water, and 20 mL of DMF were placed in an eggplant flask equipped with a reflux tube, and the interior was purged with argon. The reaction vessel was heated by irradiation with microwaves (2.45 GHz, 100 W) for 2 hours. Thereafter, water was added to this solution, and the organic layer was extracted with dichloromethane. The obtained organic layer was washed with water and saturated brine, and dried over magnesium sulfate. The solution after drying was filtered. After the solvent of this solution was distilled off, the obtained residue was purified by flash column chromatography using toluene: ethyl acetate = 9: 1 as a developing solvent to obtain the desired pyrimidine derivative HiBumoppm (abbreviation) (yellow). Oil, 94% yield). For microwave irradiation, a microwave synthesizer (Discover manufactured by CEM) was used. The synthesis scheme of Step 2 is shown in (C-2) below.

<Step 3; Di-μ-chloro-tetrakis {5-methoxy-2- [6- (2-methylpropyl) -4-pyrimidinyl-κN3] phenyl-κC} diiridium (III) (abbreviation: [Ir (iBumoppm ) _{2 Cl] 2)} synthesis of>
Next, 15 mL of 2-ethoxyethanol and 5 mL of water, 0.91 g of HiBumoppm (abbreviation) obtained in Step 2 above, and 0.54 g of iridium chloride hydrate (IrCl ₃ · H ₂ O) (manufactured by Sigma-Aldrich) The flask was placed in a recovery flask equipped with a reflux tube, and the atmosphere in the flask was replaced with argon. Then, the microwave (2.45 GHz 100W) was irradiated for 1 hour, and was made to react. After the solvent was distilled off, the resulting residue was suction filtered and washed with ethanol to obtain a binuclear complex [Ir (iBummoppm) ₂ Cl] ₂ (abbreviation) (reddish brown powder, yield 77%). The synthesis scheme of Step 3 is shown in (C-3) below.

<Step 4; Synthesis of tris {5-methoxy-2- [6- (2-methylpropyl) -4-pyrimidinyl-κN3] phenyl-κC} iridium (III) (abbreviation: [Ir (iBumoppm) ₃ ]>
Further, 10 g of phenol, 0.98 g of the binuclear complex [Ir (iBumoppm) ₂ Cl] ₂ obtained in Step 4 above, 0.85 g of HiBumoppm (abbreviation), and 0.95 g of potassium carbonate were added to a 200 mL three-necked flask equipped with a reflux tube. The flask was purged with nitrogen. Then, it heated at 185 degreeC for 8 hours, and was made to react. The obtained residue was dissolved in dichloromethane and washed with water and saturated brine. The obtained organic layer was dried over magnesium sulfate, and the dried solution was filtered. After the solvent of this solution was distilled off, the obtained residue was purified by flash column chromatography using hexane: ethyl acetate = 2: 1 as a developing solvent. The fraction was concentrated, and the obtained solid was recrystallized with a mixed solvent of dichloromethane and methanol, whereby the organometallic complex [Ir (iBumoppm) ₃ ] (abbreviation) of one embodiment of the present invention was obtained as a yellow powder ( Yield 72%). Sublimation purification of 0.86 g of the obtained yellow powder solid was performed by a train sublimation method. As the sublimation purification conditions, the solid was heated at 225 ° C. while flowing a pressure of 2.7 Pa and an argon gas at a flow rate of 5 mL / min. After the sublimation purification, the target yellow solid was obtained with a yield of 90% (UPLC purity 99.7 area%). The synthesis scheme of Step 4 is shown in (C-4) below.

In addition, the analysis result by the nuclear magnetic resonance spectroscopy (< ¹ > H-NMR) of the yellow powder obtained at the said step 4 is shown below. Further, the ¹ H-NMR chart is shown in FIG. From this result, it was confirmed in Synthesis Example 3 that the organometallic complex [Ir (iBumoppm) ₃ ] (abbreviation) of one embodiment of the present invention represented by the above structural formula (102) was obtained.

¹ H NMR data of the organometallic complex [Ir (iBumoppm) ₃ ] (abbreviation) is shown below.
¹ H-NMR. δ (CDCl ₃ ): 0.96 (d, 9H), 0.98 (d, 9H), 2.09-2.14 (m, 3H), 2.57-2.65 (m, 6H), 3.57 (s, 9H), 6.39 (d, 3H), 6.51 (dd, 3H), 7.42 (s, 3H), 7.66 (d, 3H), 8.09 (s , 3H).

Next, an ultraviolet-visible absorption spectrum (hereinafter, simply referred to as “absorption spectrum”) and an emission spectrum of [Ir (iBumoppm) ₃ ] (abbreviation) in a dichloromethane solution were measured. For the measurement of the absorption spectrum, an ultraviolet-visible spectrophotometer (model V550 manufactured by JASCO Corporation) was used, and a dichloromethane solution (0.076 mmol / L) was placed in a quartz cell and measured at room temperature. The emission spectrum was measured using a fluorometer (FS920 manufactured by Hamamatsu Photonics Co., Ltd.), and the degassed dichloromethane solution (0.076 mmol / L) was placed in a quartz cell and measured at room temperature. Measurement results of the obtained absorption spectrum and emission spectrum are shown in FIG. The horizontal axis represents wavelength, and the vertical axis represents absorption intensity and emission intensity. In FIG. 15, two solid lines are shown. A thin line represents an absorption spectrum, and a thick line represents an emission spectrum. The absorption spectrum shown in FIG. 15 shows the result of subtracting the absorption spectrum measured by putting only dichloromethane in the quartz cell from the absorption spectrum measured by putting the dichloromethane solution (0.076 mmol / L) in the quartz cell.

As shown in FIG. 15, the organometallic complex [Ir (iBumoppm) ₃ ] (abbreviation) of one embodiment of the present invention has an emission peak at 512 nm, and green light emission was observed from a dichloromethane solution.

<< Synthesis Example 4 >>
In Synthesis Example 4, the organometallic complex which is one embodiment of the present invention represented by the structural formula (111) of Embodiment 1, tris [2- (6-pentyl-4-pyrimidinyl-κN3) phenyl-κC] iridium A synthesis example of (III) (abbreviation: [Ir (nPeppm) ₃ ]) is specifically exemplified. Note that a structure of [Ir (nPeppm) ₃ ] (abbreviation) is shown below.

<Step 1: Synthesis of 4-chloro-6-pentylpyrimidine>
First, 3.0 g of 4,6-dichloropyrimidine, 0.42 g of tris (2,4-pentanedionato) iron (III), 200 mL of tetrahydrofuran (abbreviation: THF), 1-methyl-2-pyrrolidone (abbreviation: NMP) 17 mL was put into a 500 mL three-necked flask, the inside of the flask was purged with nitrogen, and ice-cooled. Furthermore, 20 mL of pentylmagnesium bromide (1M THF (abbreviation) solution) was added and stirred at room temperature for 25 hours. 1M hydrochloric acid was added to the obtained mixture, and the organic layer was extracted with ethyl acetate. The extract was washed with saturated sodium hydrogen carbonate and saturated brine, magnesium sulfate was added, and the mixture was naturally filtered. The solvent of the filtrate was distilled off and purified by flash column chromatography using dichloromethane: ethyl acetate = 10: 1 as a developing solvent to obtain 1.1 g of the desired product (yield: 30%, pale yellow oil). Thing) The synthesis scheme of Step 1 is shown in (D-1) below.

<Step 2: 4-pentyl-6-phenylpyrimidine (abbreviation: HnPeppm)>
Next, 1.1 g of 4-chloro-6-pentylpyrimidine synthesized in Step 1 above, 1.1 g of phenylboronic acid, 0.95 g of sodium carbonate, 20 mL of DMF, and 20 mL of water are placed in a 100 mL round bottom flask equipped with a reflux tube. The inside of the flask was purged with nitrogen. The mixture of bis (triphenylphosphine) palladium (II) dichloride _{(abbreviation: Pd (PPh) 2 Cl 2} ) Put 50mg, and irradiation with microwaves (2.45 GHz, 200 W) 3 hours. The organic layer was extracted with dichloromethane from the obtained mixture, washed with water and saturated brine, magnesium sulfate was added, and the mixture was naturally filtered. The solvent of the filtrate was distilled off, and the residue was purified by silica gel column chromatography using ethyl acetate: dichloromethane = 1: 10 as a developing solvent to obtain 1.1 g of the desired product (yield: 81%, orange oil) Obtained. For microwave irradiation, a microwave synthesizer (Discover manufactured by CEM) was used. The synthesis scheme of Step 2 is shown in (D-2) below.

<Step 3: Di-μ-chloro-tetrakis [2- (6-pentyl-4-pyrimidinyl-κN3) phenyl-κC] diiridium (III) (abbreviation: [Ir (nPeppm) ₂ Cl] ₂ )>
HnPeppm (abbreviation) 0.52 g synthesized in Step 2 above, 0.35 g of iridium (III) chloride hydrate, 2-ethoxyethanol 10 mL, and water 5 mL were placed in a 100 mL round bottom flask equipped with a reflux tube. Was replaced with argon, and irradiated with microwaves (2.45 GHz, 120 W) for 1 hour. The solvent of the obtained mixture was distilled off and washed with methanol to obtain 0.48 g of the desired product (60%, dark green powder solid). The synthesis scheme of Step 2 is shown in (D-3) below.

<Step 4: Tris [2- (6-pentyl-4-pyrimidinyl-κN3) phenyl-κC] iridium (III) (abbreviation: Ir (nPeppm) ₃ )>
[Ir (nPeppm) ₂ Cl] ₂ (abbreviation) 0.48 g, HnPeppm (abbreviation) 0.34 g, potassium carbonate 0.48 g, and phenol 10 g synthesized in Step 3 above were placed in a 100 mL three-necked flask equipped with a reflux tube. And heated at 180 ° C. for 6.5 hours. The resulting mixture was ultrasonically washed with methanol and filtered. Water was added to the filtrate, the organic layer was extracted with dichloromethane, washed with saturated brine, magnesium sulfate was added, and the mixture was naturally filtered. The solvent of the filtrate was distilled off, and the residue was purified by flash column chromatography using dichloromethane: ethyl acetate = 10: 1 as a developing solvent. The solvent of the obtained solution was distilled off, and recrystallization was performed with a mixed solution of dichloromethane and methanol to obtain the desired product. An organometallic complex [Ir (nPeppm) ₃ ] of one embodiment of the present invention was obtained (yield: 53% (UPLC purity 93.7 area%), orange powder solid). The synthesis scheme of Step 4 is shown in (D-4) below.

In addition, the analysis result by the nuclear magnetic resonance spectroscopy (< ¹ > H-NMR) of the orange powder obtained at the said step 4 is shown below. Further, the ¹ H-NMR chart is shown in FIG. From the results, in Synthesis Example 4, it was confirmed that the organometallic complex [Ir (nPeppm) ₃ ] (abbreviation) of one embodiment of the present invention represented by the above structural formula (111) was obtained.

¹ H NMR data of the organometallic complex [Ir (nPeppm) ₃ ] (abbreviation) is shown below.
¹ H-NMR. δ (CDCl ₃ ): 0.90-0.92 (t, 9H), 1.36-1.39 (m, 12H), 1.70-1.75 (m, 6H), 2.77-2 .80 (t, 6H), 6.81-6.83 (d, 3H), 6.89-6.96 (dm, 6H), 7.60 (s, 3H), 7.73-7.74 (D, 3H), 8.17 (s, 3H).

Next, an ultraviolet-visible absorption spectrum (hereinafter, simply referred to as “absorption spectrum”) and an emission spectrum of [Ir (nPeppm) ₃ ] (abbreviation) in a dichloromethane solution were measured. For the measurement of the absorption spectrum, an ultraviolet-visible spectrophotometer (model V550 manufactured by JASCO Corporation) was used, and a dichloromethane solution (0.12 mmol / L) was placed in a quartz cell and measured at room temperature. For measurement of the emission spectrum, a defluorinated dichloromethane solution (0.12 mmol / L) was placed in a quartz cell using a fluorometer (FS920 manufactured by Hamamatsu Photonics Co., Ltd.) and measured at room temperature. The measurement results of the obtained absorption spectrum and emission spectrum are shown in FIG. The horizontal axis represents wavelength, and the vertical axis represents absorption intensity and emission intensity. In FIG. 17, two solid lines are shown. A thin line represents an absorption spectrum and a thick line represents an emission spectrum. The absorption spectrum shown in FIG. 17 shows the result of subtracting the absorption spectrum measured by putting only dichloromethane in the quartz cell from the absorption spectrum measured by putting the dichloromethane solution (0.12 mmol / L) in the quartz cell.

As shown in FIG. 17, the organometallic complex [Ir (nPeppm) ₃ ] (abbreviation) of one embodiment of the present invention has an emission peak at 542 nm, and yellow-green light emission was observed from the dichloromethane solution.

<< Synthesis Example 5 >>
In Synthesis Example 5, an organometallic complex which is one embodiment of the present invention represented by Structural Formula (112) of Embodiment 1, bis {2- [6- (2-methylpropyl) -4-pyrimidinyl-κN3] Specific examples of the synthesis of phenyl-κC} (2,4-pentandionato-κO, O ′) iridium (III) (abbreviation: [Ir (iBupppm) ₂ (acac)]) are specifically exemplified. Note that a structure of [Ir (iBupppm) ₂ (acac)] (abbreviation) is shown below.

<Step 1: Bis {2- [6- (2-methylpropyl) -4-pyrimidinyl-κN3] phenyl-κC} (2,4-pentandionato-κO, O ′) iridium (III) (abbreviation: [ Synthesis of Ir (iBupppm) ₂ (acac)])>
First, 2.5 g of [Ir (iBupppm) ₂ Cl] ₂ (abbreviation), 0.57 g of acetylacetone (abbreviation: Hacac), 2.0 g of sodium carbonate, and 20 mL of 2-ethoxyethanol were placed in a 100 mL round bottom flask equipped with a reflux tube. The flask was purged with argon. This mixture was irradiated with microwaves (2.45 GHz, 120 W) for 1.5 hours. The obtained mixture was suction filtered with methanol, the filtrate was dissolved in dichloromethane, and passed through a filter aid laminated in the order of Celite (Wako Pure Chemical Industries, Ltd., catalog number: 531-16855), alumina, and Celite. And filtered. The solvent of the filtrate was distilled off, and recrystallization was performed with a mixed solvent of methanol and dichloromethane, whereby an organometallic complex [Ir (iBupppm) ₂ (acac)] (abbreviation) of one embodiment of the present invention was obtained ( Yield: 56%, orange powder solid). Sublimation purification of 1.5 g of the obtained orange powder solid was performed by a train sublimation method. As the sublimation purification conditions, the solid was heated between 230 ° C. and 240 ° C. while a pressure of 2.4 Pa and an argon gas flowed at a flow rate of 10 mL / min. After purification by sublimation, the target orange solid was obtained in a yield of 48% (UPLC purity of 99.9 area% or more). For microwave irradiation, a microwave synthesizer (Discover manufactured by CEM) was used. The synthesis scheme of Step 1 is shown in (E-1) below.

In addition, the analysis result by the nuclear magnetic resonance spectroscopy (< ¹ > H-NMR) of the orange powder obtained at the said step 1 is shown below. A ¹ H-NMR chart is shown in FIG. From this, in Synthesis Example 5, it was confirmed that the organometallic complex [Ir (iBupppm) ₂ (acac)] (abbreviation) of one embodiment of the present invention represented by the above structural formula (112) was obtained. It was done.

¹ H NMR data of the organometallic complex [Ir (iBupppm) ₂ (acac)] (abbreviation) is shown below.
¹ H-NMR. δ (CDCl ₃ ): 1.05-1.06 (d, 12H), 1.78 (s, 6H), 2.25-2.33 (m, 2H), 2.83-2.87 (d , 4H), 5.25 (s, 1H), 6.34-6.36 (d, 2H), 6.76-7.79 (t, 2H), 6.83-6.86 (t, 2H) ), 7.56 (s, 2H), 7.62-7.64 (d, 2H), 9.01 (s, 2H).

Next, an ultraviolet-visible absorption spectrum (hereinafter, simply referred to as “absorption spectrum”) and an emission spectrum of [Ir (iBupppm) ₂ (acac)] (abbreviation) in a dichloromethane solution were measured. For the measurement of the absorption spectrum, an ultraviolet-visible spectrophotometer (model V550 manufactured by JASCO Corporation) was used, and a dichloromethane solution (0.12 mmol / L) was placed in a quartz cell and measured at room temperature. For measurement of the emission spectrum, a defluorinated dichloromethane solution (0.12 mmol / L) was placed in a quartz cell using a fluorometer (FS920 manufactured by Hamamatsu Photonics Co., Ltd.) and measured at room temperature. The measurement results of the obtained absorption spectrum and emission spectrum are shown in FIG. The horizontal axis represents wavelength, and the vertical axis represents absorption intensity and emission intensity. In FIG. 19, two solid lines are shown. A thin line represents an absorption spectrum, and a thick line represents an emission spectrum. The absorption spectrum shown in FIG. 19 shows the result of subtracting the absorption spectrum measured by putting only dichloromethane in the quartz cell from the absorption spectrum measured by putting the dichloromethane solution (0.12 mmol / L) in the quartz cell.

As shown in FIG. 19, the organometallic complex [Ir (iBupppm) ₂ (acac)] (abbreviation) of one embodiment of the present invention has a light emission peak at 540 nm, and yellow-green light emission is observed from a dichloromethane solution. It was done.

Next, [Ir (iBupppm) ₂ (acac)] (abbreviation) obtained in this example was subjected to mass (MS) analysis by liquid chromatograph mass spectrometry (abbreviation: LC / MS analysis). went.

In LC / MS analysis, LC (liquid chromatography) separation was performed by Acquity UPLC manufactured by Waters, and MS analysis (mass spectrometry) was performed by Xevo G2 Tof MS manufactured by Waters. The column used for the LC separation was Acquity UPLC BEH C8 (2.1 × 100 mm 1.7 μm), and the column temperature was 40 ° C. As the mobile phase, mobile phase A was acetonitrile and mobile phase B was 0.1% formic acid aqueous solution. The sample was prepared by dissolving [Ir (iBupppm) ₂ (acac)] (abbreviation) of any concentration in chloroform and diluting with acetonitrile, and the injection volume was 5.0 μL.

In MS analysis, ionization by electrospray ionization (ElectroSpray Ionization (abbreviation: ESI)) was performed. At this time, the capillary voltage was 3.0 kV, the sample cone voltage was 30 V, and the detection was performed in the positive mode. The component of m / z = 715.26 ionized under the above conditions was collided with argon gas in the collision chamber (collision cell) and dissociated into product ions. The energy (collision energy) for collision with argon was 50 eV. The mass range to be measured was m / z = 100 to 1200. FIG. 20 shows the result of detecting dissociated product ions by time-of-flight (TOF) type MS.

From the results of FIG. 20, it was confirmed that [Ir (iBupppm) ₂ (acac)] (abbreviation) mainly detects product ions in the vicinity of m / z = 615,572. Incidentally, the results shown in FIG. _{20, [Ir (iBuppm) 2 (} acac)] Since shows the characteristic results from a (abbreviation), contained in the mixture [Ir _(iBuppm) 2 (acac )] (Abbreviation) can be said to be important data for identification.

Note that the product ion in the vicinity of m / z = 615 is presumed to be a cation in a state where Hacac (abbreviation) in [Ir (iBupppm) ₂ (acac)] (abbreviation) is released, and [Ir (iBupppm) ₂ (acac) ] (Abbreviation) suggests that Hacac (abbreviation) is included. Furthermore, the product ion near m / z = 572 is presumed to be a cation in which the propyl group is eliminated from the product ion near m / z = 615, and an alkyl chain is present in [Ir (iBupppm) ₃ ] (abbreviation). It is suggested that it is included.

In this example, a light-emitting element of one embodiment of the present invention will be described with reference to FIGS. The chemical formula of the material used in this example is shown below.

A method for manufacturing the light-emitting element 1 of this example is described below.

First, indium tin oxide containing silicon oxide (ITSO) was formed over a glass substrate 1100 by a sputtering method, so that a first electrode 1101 functioning as an anode was formed. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

As pretreatment for forming a light-emitting element over the substrate 1100, the surface of the substrate was washed with water, baked at 200 ° C. for 1 hour, and then subjected to UV ozone treatment for 370 seconds.

Thereafter, the substrate is introduced into a vacuum vapor deposition apparatus whose internal pressure is reduced to about 10 ⁻⁴ Pa, vacuum baking is performed at 170 ° C. for 30 minutes in a heating chamber within the vacuum vapor deposition apparatus, and then the substrate 1100 is subjected to about 30 minutes. Allowed to cool.

Next, the substrate 1100 on which the first electrode 1101 is formed is fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode 1101 is formed is downward, and 10 ⁻⁴ Pa. After reducing the pressure to the extent, 1,3,5-tri (dibenzothiophen-4-yl) -benzene (abbreviation: DBT3P-II) and molybdenum oxide (VI) are co-evaporated on the first electrode 1101. Then, a hole injection layer 1111 was formed. The film thickness was 20 nm, and the weight ratio of DBT3P-II and molybdenum oxide was adjusted to 4: 2 (= DBT3P-II: molybdenum oxide). Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

Next, 4-phenyl-4 ′-(9-phenylfluoren-9-yl) triphenylamine (abbreviation: BPAFLP) was formed over the hole injection layer 1111 so as to have a thickness of 20 nm. A hole transport layer 1112 was formed.

Furthermore, 2- [3- (dibenzothiophen-4-yl) phenyl] dibenzo [f, h] quinoxaline (abbreviation: 2mDBTBPDBq-II), N- (1,1′-biphenyl-4-yl) -9,9 -Dimethyl-N- [4- (9-phenyl-9H-carbazol-3-yl) phenyl] -9H-fluoren-2-amine (abbreviation: PCBBiF) and the tris {2- [6 synthesized in Example 1 -(2-methylpropyl) -4-pyrimidinyl-κN3] phenyl-κC} iridium (III) (abbreviation: [Ir (iBupppm) ₃ ]) was co-evaporated twice, and the first transport layer 1112 was subjected to A light emitting layer 1113 having the light emitting layer and the second light emitting layer was formed. Here, the weight ratio of 2mDBTBPDBq-II, PCBBiF, and [Ir (iBupppm) ₃ ] is 0.7: 0.3: 0.05 (= 2mDBTBBPDBq-II: PCBiF: [Ir (iBupppm) in the first light-emitting layer. ₃ ]), and the second light-emitting layer was adjusted to be 0.8: 0.2: 0.05 (= 2mDBTBPDBq-II: PCBBiF: [Ir (iBupppm) ₃ ]). . Further, the thickness of the light emitting layer 1113 was set to 20 nm for each 40 nm in total.

Next, 2mDBTBPDBq-II was formed to a thickness of 20 nm over the light-emitting layer 1113, whereby the first electron-transport layer 1114a was formed.

Next, a bathophenanthroline (abbreviation: BPhen) film was formed to a thickness of 10 nm over the first electron-transport layer 1114a, whereby a second electron-transport layer 1114b was formed.

Further, lithium fluoride (LiF) was vapor-deposited with a thickness of 1 nm on the second electron-transport layer 1114b, whereby an electron-injection layer 1115 was formed.

Lastly, as the second electrode 1103 functioning as a cathode, aluminum was deposited to a thickness of 200 nm, whereby the light-emitting element 1 of this example was manufactured.

Note that, in the above-described vapor deposition process, the vapor deposition was all performed by a resistance heating method.

Table 1 shows an element structure of the light-emitting element 1 obtained as described above.

After the light-emitting element 1 was sealed in a glove box in a nitrogen atmosphere so that the light-emitting element 1 was not exposed to the atmosphere, the operating characteristics of the light-emitting element 1 were measured. The measurement was performed at room temperature (atmosphere kept at 25 ° C.).

FIG. 22 shows voltage-current characteristics of the light-emitting element 1. In FIG. 22, the horizontal axis represents voltage (V), and the vertical axis represents current (mA). Further, voltage-luminance characteristics are shown in FIG. In FIG. 23, the horizontal axis represents voltage (V) and the vertical axis represents luminance (cd / m ² ). In addition, FIG. 24 shows luminance-current efficiency characteristics. In FIG. 24, the horizontal axis represents luminance (cd / m ² ) and the vertical axis represents current efficiency (cd / A). In addition, FIG. 25 shows luminance vs. external quantum efficiency characteristics. In FIG. 25, the horizontal axis represents luminance (cd / m ² ), and the vertical axis represents external quantum efficiency (%). Further, the voltage (V), current density (mA / cm ² ), CIE chromaticity coordinates (x, y), current efficiency (cd / A), power efficiency (lm) at a luminance of 1017 cd / m ² in the light-emitting element 1. / W) and external quantum efficiency (%) are shown in Table 2.

In addition, an emission spectrum when a current of 0.1 mA is passed through the light-emitting element 1 is shown in FIG. In FIG. 26, the horizontal axis represents wavelength (nm) and the vertical axis represents emission intensity (arbitrary unit). As shown in FIG. 26, the emission spectrum of the light-emitting element had a peak at 532 nm. As shown in Table 2, the CIE chromaticity coordinates of the light-emitting element 1 at a luminance of 1017 cd / m ² were (x, y) = (0.37, 0.61). From this result, it was found that the light-emitting element 1 emitted green light emission derived from [Ir (iBupppm) ₃ ].

As can be seen from Table 2 and FIGS. 22 to 26, the light-emitting element 1 had good luminous efficiency.

The above results indicate that an element with high emission efficiency can be realized by using the organometallic complex of one embodiment of the present invention as a light-emitting material.

Next, a reliability test of the light-emitting element 1 was performed. The result of the reliability test is shown in FIG. In FIG. 27, the vertical axis represents normalized luminance (%) when the initial luminance is 100%, and the horizontal axis represents element driving time (h).

In the reliability test, the initial luminance was set to 5000 cd / m ² and the light-emitting element 1 was driven under the condition of a constant current density.

Regarding the luminance after 330 hours, the light-emitting element 1 kept 85% of the initial luminance.

From the above results, it was shown that a highly reliable element can be realized by using the organometallic complex of one embodiment of the present invention as a light-emitting material.

(Comparative Example 1)
In this example, an organometallic complex, tris {2- [6- (tert-butyl) -4-pyrimidinyl-κN3] phenyl-κC} iridium (III) (abbreviation: [Ir (tBupppm) ₃ ]) is used as the light-emitting material. The light-emitting element used as will be described with reference to FIGS. Note that [Ir (tBupppm) ₃ ] is obtained by replacing the isobutyl group of [Ir (iBupppm) ₃ ] according to one embodiment of the present invention with a linear tert-butyl group having 2 carbon atoms. The chemical formula of the material used in this example is shown below. The materials already shown in Example 6 are omitted.

A method for manufacturing the comparative light-emitting element 1 of this example will be described.

First, indium tin oxide containing silicon oxide (ITSO) was formed over a glass substrate 1100 by a sputtering method, so that a first electrode 1101 functioning as an anode was formed. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

As pretreatment for forming a light-emitting element over the substrate 1100, the surface of the substrate was washed with water, baked at 200 ° C. for 1 hour, and then subjected to UV ozone treatment for 370 seconds.

Thereafter, the substrate is introduced into a vacuum vapor deposition apparatus whose internal pressure is reduced to about 10 ⁻⁴ Pa, vacuum baking is performed at 170 ° C. for 30 minutes in a heating chamber within the vacuum vapor deposition apparatus, and then the substrate 1100 is subjected to about 30 minutes. Allowed to cool.

Next, the substrate 1100 on which the first electrode 1101 is formed is fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode 1101 is formed is downward, and 10 ⁻⁴ Pa. After reducing the pressure to the extent, 1,3,5-tri (dibenzothiophen-4-yl) -benzene (abbreviation: DBT3P-II) and molybdenum oxide (VI) are co-evaporated on the first electrode 1101. Then, a hole injection layer 1111 was formed. The film thickness was 20 nm, and the weight ratio of DBT3P-II and molybdenum oxide was adjusted to 4: 2 (= DBT3P-II: molybdenum oxide). Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

Next, 4-phenyl-4 ′-(9-phenylfluoren-9-yl) triphenylamine (abbreviation: BPAFLP) was formed over the hole injection layer 1111 so as to have a thickness of 20 nm. A hole transport layer 1112 was formed.

Furthermore, 2- [3- (dibenzothiophen-4-yl) phenyl] dibenzo [f, h] quinoxaline (abbreviation: 2mDBTBPDBq-II), N- (1,1′-biphenyl-4-yl) -9,9 -Dimethyl-N- [4- (9-phenyl-9H-carbazol-3-yl) phenyl] -9H-fluoren-2-amine (abbreviation: PCBBiF), and tris {2- [6- (tert-butyl) -4-pyrimidinyl-κN3] phenyl-κC} iridium (III) (abbreviation: [Ir (tBupppm) ₃ ]) is co-evaporated twice, and the first light-emitting layer and the second light-emitting layer are formed on the hole-transport layer 1112. A light emitting layer 1113 having a light emitting layer was formed. Here, the weight ratio of 2mDBTBPDBq-II, PCBBiF, and [Ir (tBupppm) ₃ ] is 0.7: 0.3: 0.05 (= 2mDBTBBPDBq-II: PCBiF: [Ir (tBupppm) for the first light-emitting layer. ₃ ]), and the second light emitting layer was adjusted to be 0.8: 0.2: 0.05 (= 2mDBTBPDBq-II: PCBBiF: [Ir (tBupppm) ₃ ]). . Further, the thickness of the light emitting layer 1113 was set to 20 nm for each 40 nm in total.

Next, 2mDBTBPDBq-II was formed to a thickness of 20 nm over the light-emitting layer 1113, whereby the first electron-transport layer 1114a was formed.

Next, a bathophenanthroline (abbreviation: BPhen) film was formed to a thickness of 10 nm over the first electron-transport layer 1114a, whereby a second electron-transport layer 1114b was formed.

Further, lithium fluoride (LiF) was vapor-deposited with a thickness of 1 nm on the second electron-transport layer 1114b, whereby an electron-injection layer 1115 was formed.

Finally, as a second electrode 1103 functioning as a cathode, aluminum was deposited to a thickness of 200 nm, whereby the comparative light-emitting element 1 of this example was manufactured.

That is, in the comparative light-emitting element 1, an organometallic complex [Ir (tBupppm) ₃ ] is used instead of the organometallic complex [Ir (iBupppm) ₃ ] according to one embodiment of the present invention used for the light-emitting element 1. The light emitting device 1 was manufactured in the same manner.

Note that, in the above-described vapor deposition process, the vapor deposition was all performed by a resistance heating method.

Table 3 shows an element structure of the comparative light-emitting element 1 obtained as described above.

After performing the operation | work which sealed the comparative example light emitting element 1 so that the comparative example light emitting element 1 might not be exposed to air | atmosphere in the glove box of nitrogen atmosphere, the operating characteristic of the comparative example light emitting element 1 was measured. The measurement was performed at room temperature (atmosphere kept at 25 ° C.).

Voltage (V), current density (mA / cm ² ), CIE chromaticity coordinates (x, y), current efficiency (cd / A), power efficiency (lm) at a luminance of 1215 cd / m ² in Comparative Example Light-Emitting Element 1 / W) and external quantum efficiency (%) are shown in Table 4.

Regarding the external quantum efficiency, when the light-emitting element 1 of Example 6 which is a light-emitting element of one embodiment of the present invention and the comparative light-emitting element 1 of this example are compared, the light-emitting element 1 is 25.1%. On the other hand, it was 22.1% in the light emitting element 1 of the comparative example. That is, the organometallic complex which is one embodiment of the present invention significantly improves the external quantum efficiency of the light-emitting element as compared with [Ir (tBupppm) ₃ ].

In this example, a light-emitting element of one embodiment of the present invention will be described with reference to FIGS. The chemical formula of the material used in this example is shown below. The materials already shown in Example 6 are omitted.

A method for manufacturing the light-emitting element 2 of this example is described below.

First, indium tin oxide containing silicon oxide (ITSO) was formed over a glass substrate 1100 by a sputtering method, so that a first electrode 1101 functioning as an anode was formed. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

As pretreatment for forming a light-emitting element over the substrate 1100, the surface of the substrate was washed with water, baked at 200 ° C. for 1 hour, and then subjected to UV ozone treatment for 370 seconds.

Thereafter, the substrate is introduced into a vacuum vapor deposition apparatus whose internal pressure is reduced to about 10 ⁻⁴ Pa, vacuum baking is performed at 170 ° C. for 30 minutes in a heating chamber within the vacuum vapor deposition apparatus, and then the substrate 1100 is subjected to about 30 minutes. Allowed to cool.

Next, the substrate 1100 on which the first electrode 1101 is formed is fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode 1101 is formed is downward, and 10 ⁻⁴ Pa. After reducing the pressure to the extent, 1,3,5-tri (dibenzothiophen-4-yl) -benzene (abbreviation: DBT3P-II) and molybdenum oxide (VI) are co-evaporated on the first electrode 1101. Then, a hole injection layer 1111 was formed. The film thickness was 20 nm, and the weight ratio of DBT3P-II and molybdenum oxide was adjusted to 4: 2 (= DBT3P-II: molybdenum oxide). Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

Next, 4-phenyl-4 ′-(9-phenylfluoren-9-yl) triphenylamine (abbreviation: BPAFLP) was formed over the hole injection layer 1111 so as to have a thickness of 20 nm. A hole transport layer 1112 was formed.

Furthermore, 2- [3- (dibenzothiophen-4-yl) phenyl] dibenzo [f, h] quinoxaline (abbreviation: 2mDBTBPDBq-II), N- (1,1′-biphenyl-4-yl) -9,9 -Dimethyl-N- [4- (9-phenyl-9H-carbazol-3-yl) phenyl] -9H-fluoren-2-amine (abbreviation: PCBBiF) and tris {2- [6 synthesized in Example 2 -(2,2′-dimethylpropyl) -4-pyrimidinyl-κN3] phenyl-κC} iridium (III) (abbreviation: [Ir (Npppm) ₃ ]) was co-evaporated twice and formed on the hole transport layer 1112. A light emitting layer 1113 having a first light emitting layer and a second light emitting layer was formed. Here, the weight ratio of 2mDBTBPDBq-II, PCBBiF, and [Ir (Npppm) ₃ ] is 0.7: 0.3: 0.05 (= 2mDBTBPDBq-II: PCBBiF: [Ir (Npppm) in the first light-emitting layer. ₃ ]), and the second light-emitting layer was adjusted to be 0.8: 0.2: 0.05 (= 2mDBTBPDBq-II: PCBBiF: [Ir (Npppm) ₃ ]). . Further, the thickness of the light emitting layer 1113 was set to 20 nm for each 40 nm.

Next, 2mDBTBPDBq-II was formed to a thickness of 20 nm over the light-emitting layer 1113, whereby the first electron-transport layer 1114a was formed.

Next, a bathophenanthroline (abbreviation: BPhen) film was formed to a thickness of 10 nm over the first electron-transport layer 1114a, whereby a second electron-transport layer 1114b was formed.

Further, lithium fluoride (LiF) was vapor-deposited with a thickness of 1 nm on the second electron-transport layer 1114b, whereby an electron-injection layer 1115 was formed.

Lastly, as the second electrode 1103 functioning as a cathode, aluminum was deposited so as to have a thickness of 200 nm, whereby the light-emitting element 2 of this example was manufactured.

Note that, in the above-described vapor deposition process, the vapor deposition was all performed by a resistance heating method.

Table 5 shows an element structure of the light-emitting element 2 obtained as described above.

After the light emitting element 2 was sealed in a glove box in a nitrogen atmosphere so that the light emitting element 2 was not exposed to the atmosphere, the operating characteristics of the light emitting element 2 were measured. The measurement was performed at room temperature (atmosphere kept at 25 ° C.).

FIG. 28 shows voltage-current characteristics of the light-emitting element 2. In FIG. 28, the horizontal axis represents voltage (V) and the vertical axis represents current (mA). In addition, FIG. 29 shows voltage-luminance characteristics. In FIG. 29, the horizontal axis represents voltage (V) and the vertical axis represents luminance (cd / m ² ). In addition, FIG. 30 shows luminance-current efficiency characteristics. In FIG. 30, the horizontal axis represents luminance (cd / m ² ) and the vertical axis represents current efficiency (cd / A). In addition, FIG. 31 shows luminance vs. external quantum efficiency characteristics. In FIG. 31, the horizontal axis represents luminance (cd / m ² ) and the vertical axis represents external quantum efficiency (%). The voltage at a luminance of 1017cd / ^{m 2} of the light-emitting element 2 (V), current density ^(mA / cm 2), CIE chromaticity coordinates (x, y), current efficiency (cd / A), power efficiency (lm / W) and external quantum efficiency (%) are shown in Table 6.

Further, FIG. 32 shows an emission spectrum obtained when a current of 0.1 mA was passed through the light-emitting element 2. In FIG. 32, the horizontal axis represents wavelength (nm) and the vertical axis represents emission intensity (arbitrary unit). As shown in FIG. 32, the emission spectrum of the light-emitting element 2 had a peak at 532 nm. Further, as shown in Table 4, the CIE chromaticity coordinates of the light-emitting element 2 at a luminance of 694 cd / m ² were (x, y) = (0.36, 0.62). From this result, it was found that the light-emitting element 2 emitted green light emission derived from [Ir (Npppm) ₃ ].

As can be seen from Table 6 and FIGS. 28 to 32, the light-emitting element 2 had good luminous efficiency.

The above results indicate that an element with high emission efficiency can be realized by using the organometallic complex of one embodiment of the present invention as a light-emitting material.

In this example, a light-emitting element of one embodiment of the present invention will be described with reference to FIGS. The chemical formula of the material used in this example is shown below. The materials already shown in Example 6 are omitted.

A method for manufacturing the light-emitting element 3 of this example is described below.

First, indium tin oxide containing silicon oxide (ITSO) was formed over a glass substrate 1100 by a sputtering method, so that a first electrode 1101 functioning as an anode was formed. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

As pretreatment for forming a light-emitting element over the substrate 1100, the surface of the substrate was washed with water, baked at 200 ° C. for 1 hour, and then subjected to UV ozone treatment for 370 seconds.

Thereafter, the substrate is introduced into a vacuum vapor deposition apparatus whose internal pressure is reduced to about 10 ⁻⁴ Pa, vacuum baking is performed at 170 ° C. for 30 minutes in a heating chamber within the vacuum vapor deposition apparatus, and then the substrate 1100 is subjected to about 30 minutes. Allowed to cool.

Next, the substrate 1100 on which the first electrode 1101 is formed is fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode 1101 is formed is downward, and 10 ⁻⁴ Pa. After reducing the pressure to the extent, 1,3,5-tri (dibenzothiophen-4-yl) -benzene (abbreviation: DBT3P-II) and molybdenum oxide (VI) are co-evaporated on the first electrode 1101. Then, a hole injection layer 1111 was formed. The film thickness was 20 nm, and the weight ratio of DBT3P-II and molybdenum oxide was adjusted to 4: 2 (= DBT3P-II: molybdenum oxide). Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

Next, 4-phenyl-4 ′-(9-phenylfluoren-9-yl) triphenylamine (abbreviation: BPAFLP) was formed over the hole injection layer 1111 so as to have a thickness of 20 nm. A hole transport layer 1112 was formed.

Furthermore, 4,6-bis [3- (9H-carbazol-9-yl) phenyl] pyrimidine (abbreviation: 4,6mCzP2Pm), N- (1,1′-biphenyl-4-yl) -9,9-dimethyl -N- [4- (9-phenyl-9H-carbazol-3-yl) phenyl] -9H-fluoren-2-amine (abbreviation: PCBBiF) and tris {5-methoxy-2-synthesized in Example 3 [6- (2-Methylpropyl) -4-pyrimidinyl-κN3] phenyl-κC} iridium (III) (abbreviation: [Ir (iBumoppm) ₃ ]) was co-evaporated to form a first layer on the hole transport layer 1112. The light emitting layer 1113 having the light emitting layer and the second light emitting layer was formed. Here, the weight ratio of 4,6mCzP2Pm, PCBBiF, and [Ir (iBumoppm) ₃ ] is 0.8: 0.2: 0.05 (= 4,6mCzP2Pm: PCBiF: [Ir (iBumoppm) ₃ ]). Adjusted as follows. The thickness of the light emitting layer 1113 was 40 nm.

Next, 4,6mCzP2Pm was formed to a thickness of 20 nm over the light-emitting layer 1113, whereby the first electron-transport layer 1114a was formed.

Next, a bathophenanthroline (abbreviation: BPhen) film was formed to a thickness of 10 nm over the first electron-transport layer 1114a, whereby a second electron-transport layer 1114b was formed.

Further, lithium fluoride (LiF) was vapor-deposited with a thickness of 1 nm on the second electron-transport layer 1114b, whereby an electron-injection layer 1115 was formed.

Lastly, as the second electrode 1103 functioning as a cathode, aluminum was deposited to a thickness of 200 nm, whereby the light-emitting element 3 of this example was manufactured.

Note that, in the above-described vapor deposition process, the vapor deposition was all performed by a resistance heating method.

Table 7 shows an element structure of the light-emitting element 3 obtained as described above.

After the light emitting element 3 was sealed in a glove box in a nitrogen atmosphere so that the light emitting element 3 was not exposed to the atmosphere, the operating characteristics of the light emitting element 3 were measured. The measurement was performed at room temperature (atmosphere kept at 25 ° C.).

FIG. 33 shows voltage-current characteristics of the light-emitting element 3. In FIG. 33, the horizontal axis represents voltage (V) and the vertical axis represents current (mA). Further, voltage-luminance characteristics are shown in FIG. In FIG. 34, the horizontal axis represents voltage (V), and the vertical axis represents luminance (cd / m ² ). In addition, FIG. 35 shows luminance-current efficiency characteristics. In FIG. 35, the horizontal axis represents luminance (cd / m ² ) and the vertical axis represents current efficiency (cd / A). In addition, FIG. 36 shows luminance vs. external quantum efficiency characteristics. In FIG. 36, the horizontal axis represents luminance (cd / m ² ) and the vertical axis represents external quantum efficiency (%). In addition, the voltage (V), current density (mA / cm ² ), CIE chromaticity coordinates (x, y), current efficiency (cd / A), and power efficiency (lm) at a luminance of 1017 cd / m ² in the light-emitting element 3 / W) and external quantum efficiency (%) are shown in Table 8.

In addition, FIG. 37 shows an emission spectrum obtained when a current of 0.1 mA was passed through the light-emitting element 3. In FIG. 37, the horizontal axis represents wavelength (nm) and the vertical axis represents emission intensity (arbitrary unit). As shown in FIG. 37, the emission spectrum of the light-emitting element 3 had a peak at 504 nm. Further, as shown in Table 4, the CIE chromaticity coordinates of the light-emitting element 3 when the luminance was 846 cd / m ² were (x, y) = (0.28, 0.62). From this result, it was found that the light-emitting element 3 emitted green light derived from [Ir (iBumoppm) ₃ ].

As can be seen from Table 8 and FIGS. 33 to 37, the light-emitting element 3 had good luminous efficiency.

The above results indicate that an element with high emission efficiency can be realized by using the organometallic complex of one embodiment of the present invention as a light-emitting material.

  In this example, a light-emitting element of one embodiment of the present invention will be described with reference to FIGS. The chemical formula of the material used in this example is shown below. The materials already shown in Example 6 are omitted.

A method for manufacturing the light-emitting element 4 of this example is described below.

First, indium tin oxide containing silicon oxide (ITSO) was formed over a glass substrate 1100 by a sputtering method, so that a first electrode 1101 functioning as an anode was formed. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

As pretreatment for forming a light-emitting element over the substrate 1100, the surface of the substrate was washed with water, baked at 200 ° C. for 1 hour, and then subjected to UV ozone treatment for 370 seconds.

Thereafter, the substrate is introduced into a vacuum vapor deposition apparatus whose internal pressure is reduced to about 10 ⁻⁴ Pa, vacuum baking is performed at 170 ° C. for 30 minutes in a heating chamber within the vacuum vapor deposition apparatus, and then the substrate 1100 is subjected to about 30 minutes. Allowed to cool.

Next, the substrate 1100 on which the first electrode 1101 is formed is fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode 1101 is formed is downward, and 10 ⁻⁴ Pa. After reducing the pressure to the extent, 1,3,5-tri (dibenzothiophen-4-yl) -benzene (abbreviation: DBT3P-II) and molybdenum oxide (VI) are co-evaporated on the first electrode 1101. Then, a hole injection layer 1111 was formed. The film thickness was 20 nm, and the weight ratio of DBT3P-II and molybdenum oxide was adjusted to 4: 2 (= DBT3P-II: molybdenum oxide). Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

Next, 4-phenyl-4 ′-(9-phenylfluoren-9-yl) triphenylamine (abbreviation: BPAFLP) was formed over the hole injection layer 1111 so as to have a thickness of 20 nm. A hole transport layer 1112 was formed.

Furthermore, 2- [3- (dibenzothiophen-4-yl) phenyl] dibenzo [f, h] quinoxaline (abbreviation: 2mDBTBPDBq-II), N- (1,1′-biphenyl-4-yl) -9,9 -Dimethyl-N- [4- (9-phenyl-9H-carbazol-3-yl) phenyl] -9H-fluoren-2-amine (abbreviation: PCBBiF) and the bis {2- [6 synthesized in Example 5 -(2-Methylpropyl) -4-pyrimidinyl-κN3] phenyl-κC} (2,4-pentandionato-κO, O ′) iridium (III) (abbreviation: [Ir (iBupppm) ₂ (acac)]) Was co-evaporated twice to form a light-emitting layer 1113 having a first light-emitting layer and a second light-emitting layer over the hole-transport layer 1112. Here, the weight ratio of 2mDBTBPDBq-II, PCBBiF, and [Ir (iBupppm) ₂ (acac)] is 0.7: 0.3: 0.05 (= 2mDBTBPDBq-II: PCBBiF: [ Ir (iBupppm) ₂ (acac)]), and the second light-emitting layer has a ratio of 0.8: 0.2: 0.05 (= 2mDBTBPDBq-II: PCBiF: [Ir (iBupppm) ₂ (acac). )]). Further, the thickness of the light emitting layer 1113 was set to 20 nm for each 40 nm in total.

Next, 2mDBTBPDBq-II was formed to a thickness of 20 nm over the light-emitting layer 1113, whereby the first electron-transport layer 1114a was formed.

Next, a bathophenanthroline (abbreviation: BPhen) film was formed to a thickness of 10 nm over the first electron-transport layer 1114a, whereby a second electron-transport layer 1114b was formed.

Further, lithium fluoride (LiF) was vapor-deposited with a thickness of 1 nm on the second electron-transport layer 1114b, whereby an electron-injection layer 1115 was formed.

Lastly, as the second electrode 1103 functioning as a cathode, aluminum was deposited to a thickness of 200 nm, whereby the light-emitting element 4 of this example was manufactured.

Note that, in the above-described vapor deposition process, the vapor deposition was all performed by a resistance heating method.

Table 9 shows an element structure of the light-emitting element 4 obtained as described above.

After the light-emitting element 4 was sealed in a glove box in a nitrogen atmosphere so that the light-emitting element 4 was not exposed to the atmosphere, the operating characteristics of the light-emitting element 4 were measured. The measurement was performed at room temperature (atmosphere kept at 25 ° C.).

The voltage-current characteristics of the light-emitting element 4 are shown in FIG. In FIG. 38, the horizontal axis represents voltage (V) and the vertical axis represents current (mA). In addition, FIG. 39 shows voltage-luminance characteristics. In FIG. 39, the horizontal axis represents voltage (V) and the vertical axis represents luminance (cd / m ² ). In addition, FIG. 40 shows luminance-current efficiency characteristics. In FIG. 40, the horizontal axis represents luminance (cd / m ² ) and the vertical axis represents current efficiency (cd / A). In addition, FIG. 41 shows luminance vs. external quantum efficiency characteristics. In FIG. 41, the horizontal axis represents luminance (cd / m ² ) and the vertical axis represents external quantum efficiency (%). Further, the voltage (V), current density (mA / cm ² ), CIE chromaticity coordinates (x, y), current efficiency (cd / A), power efficiency (lm) in the light emitting element 4 at a luminance of 816 cd / m ^2. / W) and external quantum efficiency (%) are shown in Table 10.

In addition, FIG. 42 shows an emission spectrum obtained when a current of 0.1 mA was passed through the light-emitting element 4. In FIG. 42, the horizontal axis represents wavelength (nm) and the vertical axis represents emission intensity (arbitrary unit). As shown in FIG. 42, the emission spectrum of the light-emitting element 4 had a peak at 545 nm. Further, as shown in Table 8, the CIE chromaticity coordinates of the light-emitting element 4 at a luminance of 816 cd / m ² were (x, y) = (0.42, 0.57). From this result, it was found that the light-emitting element 4 emitted yellowish green light derived from [Ir (iBupppm) ₂ (acac)].

As can be seen from Table 10 and FIGS. 38 to 42, the light-emitting element 4 had good luminous efficiency.

The above results indicate that an element with high emission efficiency can be realized by using the organometallic complex of one embodiment of the present invention as a light-emitting material.

Next, a reliability test of the light emitting element 4 was performed. The result of the reliability test is shown in FIG. In FIG. 43, the vertical axis represents normalized luminance (%) when the initial luminance is 100%, and the horizontal axis represents element driving time (h).

In the reliability test, the initial luminance was set to 5000 cd / m ² and the light-emitting element 4 was driven under the condition of a constant current density.

Regarding the luminance after 980 hours, the light-emitting element 4 kept 85% of the initial luminance.

From the above results, it was shown that a highly reliable element can be realized by using the organometallic complex of one embodiment of the present invention as a light-emitting material.

In this example, a light-emitting element of one embodiment of the present invention will be described with reference to FIGS. The chemical formula of the material used in this example is shown below. The materials already shown in Example 6 are omitted.

A method for manufacturing the light-emitting element 5 of this example is described below.

First, indium tin oxide containing silicon oxide (ITSO) was formed over a glass substrate 1100 by a sputtering method, so that a first electrode 1101 functioning as an anode was formed. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

As pretreatment for forming a light-emitting element over the substrate 1100, the surface of the substrate was washed with water, baked at 200 ° C. for 1 hour, and then subjected to UV ozone treatment for 370 seconds.

Thereafter, the substrate is introduced into a vacuum vapor deposition apparatus whose internal pressure is reduced to about 10 ⁻⁴ Pa, vacuum baking is performed at 170 ° C. for 30 minutes in a heating chamber within the vacuum vapor deposition apparatus, and then the substrate 1100 is subjected to about 30 minutes. Allowed to cool.

Next, the substrate 1100 on which the first electrode 1101 is formed is fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode 1101 is formed is downward, and 10 ⁻⁴ Pa. After reducing the pressure to the extent, 1,3,5-tri (dibenzothiophen-4-yl) -benzene (abbreviation: DBT3P-II) and molybdenum oxide (VI) are co-evaporated on the first electrode 1101. Then, a hole injection layer 1111 was formed. The film thickness was 20 nm, and the weight ratio of DBT3P-II and molybdenum oxide was adjusted to 4: 2 (= DBT3P-II: molybdenum oxide). Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

Next, 4-phenyl-4 ′-(9-phenylfluoren-9-yl) triphenylamine (abbreviation: BPAFLP) was formed over the hole injection layer 1111 so as to have a thickness of 20 nm. A hole transport layer 1112 was formed.

Furthermore, 2- [3- (dibenzothiophen-4-yl) phenyl] dibenzo [f, h] quinoxaline (abbreviation: 2mDBTBPDBq-II), N- (1,1′-biphenyl-4-yl) -9,9 -Dimethyl-N- [4- (9-phenyl-9H-carbazol-3-yl) phenyl] -9H-fluoren-2-amine (abbreviation: PCBBiF) and tris [2- (6 -Pentyl-4-pyrimidinyl-κN3) phenyl-κC] iridium (III) (abbreviation: [Ir (nPeppm) ₃ ]) was co-evaporated to form a light-emitting layer 1113 over the hole-transport layer 1112. Here, the weight ratio of 2mDBTBPDBq-II, PCBBiF, and [Ir (nPeppm) ₃ ] is 0.8: 0.2: 0.05 (= 2mDBTBPDBq-II: PCBiF: [Ir (nPeppm) ₃ ]). Adjusted as follows. The thickness of the light emitting layer 1113 was 40 nm.

Next, 2mDBTBPDBq-II was formed to a thickness of 20 nm over the light-emitting layer 1113, whereby the first electron-transport layer 1114a was formed.

Next, a bathophenanthroline (abbreviation: BPhen) film was formed to a thickness of 10 nm over the first electron-transport layer 1114a, whereby a second electron-transport layer 1114b was formed.

Further, lithium fluoride (LiF) was vapor-deposited with a thickness of 1 nm on the second electron-transport layer 1114b, whereby an electron-injection layer 1115 was formed.

Lastly, as the second electrode 1103 functioning as a cathode, aluminum was deposited to a thickness of 200 nm, whereby the light-emitting element 5 of this example was manufactured.

Note that, in the above-described vapor deposition process, the vapor deposition was all performed by a resistance heating method.

Table 5 shows an element structure of the light-emitting element 5 obtained as described above.

After performing the operation | work which sealed the light emitting element 5 in the glove box of nitrogen atmosphere so that the light emitting element 5 might not be exposed to air | atmosphere, the operating characteristic of the light emitting element 5 was measured. The measurement was performed at room temperature (atmosphere kept at 25 ° C.).

FIG. 44 shows voltage-current characteristics of the light-emitting element 5. In FIG. 44, the horizontal axis represents voltage (V) and the vertical axis represents current (mA). In addition, FIG. 45 shows voltage-luminance characteristics. In FIG. 45, the horizontal axis represents voltage (V) and the vertical axis represents luminance (cd / m ² ). In addition, FIG. 46 shows luminance-current efficiency characteristics. In FIG. 46, the horizontal axis represents luminance (cd / m ² ) and the vertical axis represents current efficiency (cd / A). In addition, FIG. 47 shows luminance vs. external quantum efficiency characteristics. In FIG. 47, the horizontal axis represents luminance (cd / m ² ) and the vertical axis represents external quantum efficiency (%). Further, the voltage (V), current density (mA / cm ² ), CIE chromaticity coordinates (x, y), current efficiency (cd / A), power efficiency (lm) in the light emitting element 5 at a luminance of 1048 cd / m ^2. / W) and external quantum efficiency (%) are shown in Table 12.

In addition, an emission spectrum when a current of 0.1 mA is passed through the light-emitting element 5 is shown in FIG. In FIG. 48, the horizontal axis represents wavelength (nm) and the vertical axis represents emission intensity (arbitrary unit). As shown in FIG. 48, the emission spectrum of the light-emitting element 5 had a peak at 545 nm. Further, as shown in Table 12, the CIE chromaticity coordinates of the light-emitting element 5 at the luminance of 694 cd / m ² were (x, y) = (0.40, 0.59). From this result, it was found that the light-emitting element 5 emitted green light emission derived from [Ir (nPeppm) ₃ ].

As can be seen from Table 12 and FIGS. 44 to 48, the light-emitting element 5 had good luminous efficiency.

The above results indicate that an element with high emission efficiency can be realized by using the organometallic complex of one embodiment of the present invention as a light-emitting material.

(Comparative Example 2)
In this example, as in Comparative Example 1, tris {2- [6- (tert-butyl) -4-pyrimidinyl-κN3] phenyl-κC} iridium (III) (abbreviation: [Ir (tBupppm) ₃ ]) A comparative light-emitting element 2 having the structure shown in FIG. Comparative Example emitting element 2, other than the light-emitting material is a light-emitting element having the same structure as the light emitting element 5, the light emitting material was used [Ir _{(tBuppm) 3]} instead of [Ir _{(nPeppm) 3].} The production method of the comparative light-emitting element 2 is the same as the production method of the light-emitting element 5 except for the process of creating the light-emitting layer.

A method for manufacturing the light-emitting layer of the comparative light-emitting element 2 of this example will be described.

2- [3- (Dibenzothiophen-4-yl) phenyl] dibenzo [f, h] quinoxaline (abbreviation: 2mDBTBPDBq-II), N- (1,1′-biphenyl-4-yl) -9,9-dimethyl -N- [4- (9-phenyl-9H-carbazol-3-yl) phenyl] -9H-fluoren-2-amine (abbreviation: PCBBiF) and tris {2- [6- (tert-butyl) -4 -Pyrimidinyl-κN3] phenyl-κC} iridium (III) (abbreviation: [Ir (tBupppm) ₃ ]) was co-evaporated to form a light-emitting layer 1113 over the hole-transport layer 1112. Here, the weight ratio of 2mDBTBPDBq-II, PCBBiF, and [Ir (tBupppm) ₃ ] is 0.8: 0.2: 0.05 (= 2mDBTBBPDBq-II: PCBiF: [Ir (tBupppm) ₃ ]). Adjusted as follows. The thickness of the light emitting layer 1113 was 40 nm.

That is, in the comparative light-emitting element 2, the organometallic complex [Ir (tBupppm) ₃ ] is used instead of the organometallic complex [Ir (nPeppm) ₃ ] according to one embodiment of the present invention used for the light-emitting element 5. Thus, the light emitting device 5 was manufactured in the same manner.

Table 13 shows an element structure of the comparative light-emitting element 2 obtained as described above.

After performing the operation | work which sealed the comparative example light emitting element 2 in the glove box of nitrogen atmosphere so that the comparative example light emitting element 2 might not be exposed to air | atmosphere, the operational characteristic of the comparative example light emitting element 2 was measured. The measurement was performed at room temperature (atmosphere kept at 25 ° C.).

Voltage (V), current density (mA / cm ² ), CIE chromaticity coordinates (x, y), current efficiency (cd / A), power efficiency (lm) at a luminance of 1090 cd / m ² in Comparative Example Light-Emitting Element 1 / W) and external quantum efficiency (%) are shown in Table 14.

Regarding the external quantum efficiency, when the light-emitting element 5 of Example 11 which is a light-emitting element of one embodiment of the present invention and the comparative light-emitting element 2 of this example are compared, the light-emitting element 5 is 22.5%. On the other hand, in the comparative light emitting element 1, it was 21.6%. That is, it was confirmed that the organometallic complex which is one embodiment of the present invention has improved external quantum efficiency of the light-emitting element as compared with [Ir (tBupppm) ₃ ].

101 1st electrode 102 EL layer 103 2nd electrode 111 Hole injection layer 112 Hole transport layer 113 Light emitting layer 114 Electron transport layer 115 Electron injection layer 213 1st light emitting layer 214 Separation layer 215 2nd light emitting layer 305 Charge generation layer 401 Substrate 402 Insulating layer 403 First electrode 404 Partition 405 Opening 406 Partition 407 EL layer 408 Second electrode 501 Substrate 503 Scan line 505 Region 506 Partition 508 Data line 509 Connection wiring 510 Input terminal 512 Input terminal 601 Element substrate 602 Pixel portion 603 Drive circuit portion 604 Drive circuit portion 605 Seal material 606 Sealing substrate 607 Wiring 608 FPC
609 n-channel FET
610 p-channel FET
611 FET for switching
612 FET for current control
613 Anode 614 Insulator 615 EL layer 616 Cathode 617 Light-emitting element 618 Space 700 First EL layer 701 Second EL layer 801 Lighting device 802 Lighting device 803 Desktop lighting fixture 511a FPC
511b FPC
1100 Substrate 1101 First electrode 1103 Second electrode 1111 Hole injection layer 1112 Hole transport layer 1113 Light emitting layer 1114a First electron transport layer 1114b Second electron transport layer 1115 Electron injection layer 7100 Television apparatus 7101 Housing 7103 Display unit 7105 Stand 7107 Display unit 7109 Operation key 7110 Remote control device 7201 Main unit 7202 Case 7203 Display unit 7204 Keyboard 7205 External connection port 7206 Pointing device 7301 Case 7302 Case 7303 Connection unit 7304 Display unit 7305 Display unit 7306 Speaker unit 7307 Recording medium insertion portion 7308 LED lamp 7309 Operation key 7310 Connection terminal 7311 Sensor 7312 Microphone 7400 Mobile phone 7401 Case 7402 Display portion 7403 Create button 7404 an external connection port 7405 speaker 7406 microphone 7501 lighting unit 7502 umbrella 7503 adjustable arm 7504 posts 7505 units 7506 power 9501 lighting unit 9503 posts 9505 support stand 9900 Lighting device

Claims (15)

An organometallic complex having a structure represented by General Formula (G1).
Wherein R ¹¹ represents a substituted or unsubstituted branched alkyl group having 4 or more carbon atoms and a straight chain carbon number of 3 or more, and R ² is hydrogen, substituted or unsubstituted carbon Represents an alkyl group having 1 to 6 or a substituted or unsubstituted phenyl group, R ³ represents hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, and R ^{4 to} R ⁷ each represents Independently, hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted alkylthio group having 1 to 6 carbon atoms, a halogen group, A substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms is represented.) An organometallic complex having a structure represented by General Formula (G2).

(Wherein R ¹² represents a substituted or unsubstituted alkyl group having 5 to 10 carbon atoms, R ² represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted alkyl group; Represents a phenyl group, R ³ represents hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, and R ^{4 to} R ⁷ each independently represents hydrogen, a substituted or unsubstituted carbon atom having 1 to 6 carbon atoms. 6 alkyl groups, substituted or unsubstituted alkoxy groups having 1 to 6 carbon atoms, substituted or unsubstituted alkylthio groups having 1 to 6 carbon atoms, halogen groups, substituted or unsubstituted haloalkyl groups having 1 to 6 carbon atoms, Or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms.) An organometallic complex represented by the general formula (G3).

(In the formula, L represents a monoanionic ligand. R ¹¹ represents a substituted or unsubstituted branched alkyl group having 4 or more carbon atoms and a straight chain carbon number of 3 or more. , R ² represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted phenyl group, and R ³ represents hydrogen or substituted or unsubstituted carbon atoms having 1 to 6 carbon atoms. R ^{4 to} R ⁷ each independently represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, substituted or unsubstituted Represents an alkylthio group having 1 to 6 carbon atoms, a halogen group, a substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms.) An organometallic complex represented by the general formula (G4).

(In the formula, L represents a monoanionic ligand. R ¹² represents a substituted or unsubstituted alkyl group having 5 to 10 carbon atoms, and R ² represents hydrogen, substituted or unsubstituted carbon number. 1 to 6 alkyl group or a substituted or unsubstituted phenyl group, R ³ represents hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, and R ^{4 to} R ⁷ are each independently Hydrogen, substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, substituted or unsubstituted alkylthio group having 1 to 6 carbon atoms, halogen group, substituted Alternatively, it represents an unsubstituted haloalkyl group having 1 to 6 carbon atoms or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms.) In any one of Claims 3 thru | or 4,
The monoanionic ligand includes a monoanionic bidentate chelate ligand having a beta diketone structure, a monoanionic bidentate chelate ligand having a carboxyl group, and a monoanionic group having a phenolic hydroxyl group. An organometallic complex which is a bidentate chelate ligand or a monoanionic bidentate chelate ligand in which two coordination elements are both nitrogen. In any one of Claims 3 thru | or 4,
The monoanionic ligand is an organometallic complex represented by any one of general formulas (L1) to (L7).

Wherein R ^{71 to} R ¹⁰⁹ are each independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a halogen group, a vinyl group, or a substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms. Represents a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, or a substituted or unsubstituted alkylthio group having 1 to 6 carbon atoms, and A ^{1 to} A ³ are independently bonded to nitrogen and hydrogen. Sp ² hybrid carbon, or sp ² carbon bonded to the substituent R, wherein the substituent R represents an alkyl group having 1 to 6 carbon atoms, a halogen group, a haloalkyl group having 1 to 6 carbon atoms, or a phenyl group. .) An organometallic complex represented by the general formula (G5).

Wherein R ¹¹ represents a substituted or unsubstituted branched alkyl group having 4 or more carbon atoms and a straight chain carbon number of 3 or more, and R ² is hydrogen, substituted or unsubstituted carbon Represents an alkyl group having 1 to 6 or a substituted or unsubstituted phenyl group, R ³ represents hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, and R ^{4 to} R ⁷ each represents Independently, hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted alkylthio group having 1 to 6 carbon atoms, a halogen group, A substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms is represented.) An organometallic complex represented by the general formula (G6).

(Wherein R ¹² represents a substituted or unsubstituted alkyl group having 5 to 10 carbon atoms, R ² represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted alkyl group; Represents a phenyl group, R ³ represents hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, and R ^{4 to} R ⁷ each independently represents hydrogen, a substituted or unsubstituted carbon atom having 1 to 6 carbon atoms. 6 alkyl groups, substituted or unsubstituted alkoxy groups having 1 to 6 carbon atoms, substituted or unsubstituted alkylthio groups having 1 to 6 carbon atoms, halogen groups, substituted or unsubstituted haloalkyl groups having 1 to 6 carbon atoms, Or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms.) An organometallic complex represented by the structural formula (100).
An organometallic complex represented by the structural formula (101).
An organometallic complex represented by the structural formula (102).
An organometallic complex represented by the structural formula (111).
An organometallic complex represented by the structural formula (112).
In a light-emitting element having an organometallic complex in a light-emitting layer,
The organometallic complex has a bond with the central metal of Group 9 or Group 10 on the nitrogen atom at the 3-position of the pyrimidine skeleton,
The organometallic complex has a bond with a benzene ring at the 4-position carbon atom of the pyrimidine skeleton,
The organometallic complex has a bond with the Group 9 or Group 10 metal on the benzene ring,
The organometallic complex has a bond with the first substituent at the 6-position carbon atom of the pyrimidine skeleton,
The light-emitting element in which the first substituent is a substituted or unsubstituted branched alkyl group having 4 or more carbon atoms and a straight chain carbon number of 3 or more. In a light-emitting element having an organometallic complex in a light-emitting layer,
The organometallic complex has a bond with the central metal of Group 9 or Group 10 on the nitrogen atom at the 3-position of the pyrimidine skeleton,
The organometallic complex has a bond with a benzene ring at the 4-position carbon atom of the pyrimidine skeleton,
The organometallic complex has a bond with the Group 9 or Group 10 metal on the benzene ring,
The organometallic complex has a bond with the first substituent at the 6-position carbon atom of the pyrimidine skeleton,
The light-emitting element in which the first substituent is a substituted or unsubstituted alkyl group having 5 to 10 carbon atoms.