KR102628129B1 - Material for organic electroluminescent element, and organic electroluminescent element - Google Patents

Abstract

A practically useful organic EL device with high efficiency and high driving stability and a compound suitable therefor are provided. It is represented by the general formula (1), has a skeletal structure in which an aromatic hydrocarbon group and/or an aromatic heterocyclic group are connected, the molecular weight of the skeletal structure without a substituent is 500 or more and 1500 or less, and is generated by conformation search calculation of the skeletal structure. It is a compound for organic electroluminescent devices with a structure in which the number of three-dimensional conformations is 9 to 100,000. Here, Ar is an aromatic hydrocarbon group with 6 to 30 carbon atoms, an aromatic heterocyclic group with 3 to 24 carbon atoms, or a connected aromatic group in which 2 to 10 of these aromatic rings are linked, and HetAr is an aromatic heterocyclic group with 3 to 24 carbon atoms. Ventilation, and z is an integer from 2 to 5.

Description

Material for organic electroluminescent element and organic electroluminescent element {Material for organic electroluminescent element, and organic electroluminescent element}

The present invention relates to materials for organic electroluminescent devices, organic electroluminescent device films, and organic electroluminescent devices (hereinafter referred to as organic EL devices), and more specifically, to organic EL devices using compounds having a conformation number in a specific range. It's about the ingredients.

By applying voltage to the organic EL element, holes are injected from the anode and electrons from the cathode are injected into the light emitting layer. And in the light-emitting layer, the injected holes and electrons recombine, and excitons are generated. At this time, by the statistical side of the electron spin, singlet excitons and triplet excitons are generated in a ratio of 1:3. It is said that the internal quantum efficiency of fluorescent organic EL devices that use light emission from singlet excitons is limited to 25%. On the other hand, it is known that the internal quantum efficiency of a phosphorescent organic EL device that uses light emission by triplet excitons increases to 100% when intersystem crossing is efficiently achieved from singlet excitons.

However, with regard to phosphorescent organic EL devices, extending the lifespan is a technical issue.

Moreover, recently, high-efficiency organic EL devices using delayed fluorescence have been developed. For example, Patent Document 1 discloses an organic EL device using a Triplet-Triplet Fusion (TTF) mechanism, which is one of the delayed fluorescence mechanisms. The TTF mechanism utilizes the phenomenon of singlet excitons being created by the collision of two triplet excitons, and is believed to theoretically be able to increase internal quantum efficiency by up to 40%. However, since the efficiency is low compared to phosphorescent organic EL devices, further improvement in efficiency is required.

Meanwhile, Patent Document 2 discloses an organic EL device using a TADF (Thermally Activated Delayed Fluorescence) mechanism. The TADF mechanism utilizes the phenomenon of reverse intersystem crossing from triplet excitons to singlet excitons in materials where the energy difference between the singlet level and triplet level is small, and is believed to theoretically be able to increase internal quantum efficiency up to 100%. there is. However, as with phosphorescent devices, further improvement in lifespan characteristics is required.

WO2010/134350 WO2011/070963 WO2008/056746 WO2010/098246 WO2011/136755

Patent Document 3 discloses the use of an indolocarbazole compound as a host material.

Patent Document 4 discloses using an indolocarbazole compound as a mixed host.

Patent Document 5 discloses the use of a host material obtained by premixing a plurality of hosts containing an indolocarbazole compound.

However, it cannot be said that all are sufficient, and further improvements are required. Additionally, there is no teaching on using compounds having a conformation number in a specific range as materials for organic electroluminescent devices.

In order to apply an organic EL device to a display device such as a flat panel display, it is necessary to improve the luminous efficiency of the device and at the same time ensure sufficient stability during operation. In consideration of the above-mentioned current situation, the purpose of the present invention is to provide a practically useful organic EL device with high efficiency and high driving stability and a compound suitable therefor.

As a result of intensive studies, the present inventors have discovered that the above problems can be solved by using a compound having a conformation number in a specific range as a material for an organic electroluminescent device, and have completed the present invention.

The present invention is represented by the general formula (1), has a skeletal structure in which an aromatic hydrocarbon group and/or an aromatic heterocyclic group are linked, the molecular weight of the skeletal structure without a substituent is 500 or more and 1500 or less, and conformation search calculation of the skeletal structure It is a compound for an organic electroluminescent device characterized by having a structure in which the number of three-dimensional conformations generated is 9 to 100,000.

[Formula 1]

Here, Ar is independently a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 24 carbon atoms, or a substituted or unsubstituted group in which 2 to 10 of these aromatic rings are linked. It represents an unsubstituted connected aromatic group. HetAr represents a substituted or unsubstituted aromatic heterocyclic group having 3 to 24 carbon atoms. z represents an integer from 2 to 5.

Among the compounds represented by the general formula (1), compounds represented by the general formula (2) and the number of conformations generated by conformation search calculations are greater than 4 × 2 ⁿ and not more than 4 × 4 ^{n + 1} are preferable. Here, n is an integer obtained by subtracting 4 from the total number of Ar ² to Ar ⁷ .

[Formula 2]

Here, ring A represents an aromatic ring represented by the formula (A2) in which two adjacent rings are condensed at an arbitrary position. Ring B represents a nitrogen-containing 5-membered ring represented by the formula (B2) in which two adjacent rings are condensed at arbitrary positions.

L is independently a substituted or unsubstituted aromatic group or a connected aromatic group represented by formula (c2), Ar ¹ to Ar ⁷ are each independently Ar ¹ , Ar ³ and Ar ⁵ are divalent, and Ar ² is i+ monovalent, Ar ⁴ is h+1-valent, Ar ⁶ is g+1-valent, and Ar ⁷ is a monovalent aromatic hydrocarbon group with 6 to 24 carbon atoms, or an aromatic heterocyclic group with 3 to 16 carbon atoms, and these aromatic hydrocarbons The group or aromatic heterocyclic group may each independently have a substituent Q, and when it has a substituent, the substituent Q may be deuterium, halogen, cyano group, nitro group, alkyl group with 1 to 20 carbon atoms, or arboreal group with 7 to 38 carbon atoms. Alkyl group, alkenyl group with 2 to 20 carbon atoms, alkynyl group with 2 to 20 carbon atoms, dialkylamino group with 2 to 40 carbon atoms, diarylamino group with 12 to 44 carbon atoms, dialkylamino group with 14 to 76 carbon atoms , an acyl group with 2 to 20 carbon atoms, an acyloxy group with 2 to 20 carbon atoms, an alkoxy group with 1 to 20 carbon atoms, an alkoxycarbonyl group with 2 to 20 carbon atoms, an alkoxycarbonyloxy group with 2 to 20 carbon atoms, It is an alkylsulfonyl group having 1 to 20 carbon atoms, or a group in which the hydrogen atom in these hydrocarbon groups is replaced with deuterium or halogen.

R ¹ to R ³ each independently represent a substituent Q or L.

At least one of L has a total number of Ar ² to Ar ⁷ of 4 or more.

a, b, and c represent the number of substitutions, and each independently represents an integer from 0 to 2. d, e, and f represent the number of repetitions and each independently represents an integer from 0 to 5. g, h, and i represent the number of substitutions, and each independently represents an integer from 0 to 5.

It is preferable that the sum of the numbers of Ar ¹ to Ar ⁷ included in all L in General Formula (2) is 6 or more and 10 or less.

The compound represented by general formula (2) includes a compound for organic electroluminescent devices represented by general formula (3).

[Formula 3]

Here, ring C represents an aromatic ring represented by the formula (C3) in which two adjacent rings are condensed at arbitrary positions. Ring D represents a nitrogen-containing 5-membered ring represented by the formula (D3) in which two adjacent rings are condensed at arbitrary positions. L has the same meaning as in general formula (2), and Ar ² in at least one L represents an i+1 valent substituted or unsubstituted aromatic heterocyclic group having 3 to 9 carbon atoms.

L in the general formula (3) may be a group represented by the following formula (c5).

[Formula 4]

Here, Ar ¹ , Ar ³ ~Ar ⁷ , and d~i have the same meaning as in formula (c2), X each independently represents CH, C-, or nitrogen, and at least one of X represents nitrogen.

In General Formula (3), i in L is 2 to 4, and the i substituents may be different.

In general formula (3), any one of Ar ² to Ar ⁷ in L may have at least one partial structure represented by formula (4). Preferably, there may be two or more. Additionally, in general formula (3), any one of L is a group L ² represented by formula (c2) other than formula (c5), and any one of Ar ² to Ar ⁷ in L ² is represented by formula (4). It is good to have at least one structure.

[Formula 5]

In general formula (3), it is preferred that any one of Ar ² to Ar ⁷ in L has at least one partial structure represented by formula (5).

[Formula 6]

In general formula (3), Ar ¹ , Ar ³ to Ar ⁷ in L are preferably aromatic hydrocarbon groups having 6 carbon atoms. Additionally, in the general formula (3), at least one of L is the formula (c5), and Ar ³ to Ar ⁷ in the formula (c5) may have at least one partial structure represented by the formula (5).

Preferred aspects of the present invention are shown below.

The above compound for an organic electroluminescent device having a solubility in toluene of 1% or more at 40°C.

Another aspect is a material for an organic electroluminescent device containing at least one of the above compounds for an organic electroluminescent device.

Another aspect is an organic electroluminescent device including an organic layer made of the above organic electroluminescent device material.

Another aspect is a composition for an organic electroluminescent device formed by dissolving or dispersing the above-mentioned material for an organic electroluminescent device in a solvent.

Another aspect is an organic electroluminescent device including an organic layer made of a coating film of the composition for an organic electroluminescent device described above.

The organic layer is preferably at least one layer selected from a light emitting layer, a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a hole blocking layer, and an electron blocking layer, and is preferably a light emitting layer. This light-emitting layer may contain a light-emitting dopant material.

The material for an organic electroluminescent device of the present invention includes the compound for an organic electroluminescent device of the present invention. This compound has a structure in which multiple aromatic rings, including aromatic heterocycles, are connected, and can adopt various three-dimensional configurations, so its crystallinity is lower than that of materials with structures with few configurations, and the organic compounds of the present invention have low crystallinity. By using materials for electroluminescent devices, a film with high amorphous stability can be formed.

When the compound for an organic electroluminescent device of the present invention is a compound having an indolocarbazole skeleton, it becomes a material for an organic electroluminescent device with high stability in oxidation, reduction, and exciton activation states and high heat resistance. Organic electroluminescent devices using the formed organic thin films exhibit high luminous efficiency and driving stability.

When the material for an organic electroluminescent device of the present invention is a mixture containing at least one compound for an organic electroluminescent device of the present invention, the mixture is used in the same organic electroluminescent device layer to maintain the carrier balance of holes and electrons in the layer. Adjustment becomes possible, making it possible to realize a more high-performance organic EL device.

In addition, since the material for an organic electroluminescent device of the present invention can have various three-dimensional structures as described above, the packing between molecules is weak and solubility in organic solvents is high. For this reason, this material is also adaptable to the application process.

1 is a schematic cross-sectional view showing an example of an organic EL device.
Figure 2 is an XRD measurement chart after heating a compound for an organic EL device.

The modes for carrying out the present invention are described in detail below.

The compound for an organic electroluminescent device of the present invention has a molecular weight of 500 or more and 1,500 or less of a skeletal structure consisting only of a connection between an aromatic hydrocarbon group and an aromatic heterocyclic group that does not contain a substituent, and has a conformational conformation generated by a conformation search calculation of the skeletal structure. It has a structure in which the number is 9 to 100,000, and is represented by the general formula (1) above.

The compound for an organic electroluminescent device of the present invention has a skeletal structure in which the aromatic ring of an aromatic group selected from an aromatic hydrocarbon group and an aromatic heterocyclic group is directly bonded, and may have a non-aromatic substituent such as an alkyl group. . That is, the skeletal structure referred to in this specification consists only of an aromatic ring and does not include a substituent to replace it. The skeletal structure may be linear or branched.

The molecular weight of the skeletal structure alone is 500 to 1500. If the molecular weight is too low, the amorphous stability of the material may decrease, and if the molecular weight is too high, the heating temperature required for vapor deposition increases, and the material The likelihood of decomposition increases. Therefore, the range of molecular weight is 500 to 1500, preferably 600 to 1300, and more preferably 700 to 1100.

In addition, the compound for an organic electroluminescent device of the present invention has a skeletal structure in which the number of conformations generated by conformation search calculation is 9 to 100,000. If the number of conformations is too small, the amorphous stability of the material may decrease. Additionally, if the number of conformations is too large, the volume fraction of structures related to charge transport and light emission decreases, so the charge transport characteristics and luminescence characteristics deteriorate, making it an excellent organic electroluminescent device. Therefore, the range of the number of conformations in the skeletal structure of the compound for an organic electroluminescent device of the present invention is 9 to 100,000, preferably 12 to 50,000, and more preferably 15 to 20,000.

Here, the stereoconfiguration refers to a locally stable structure that can be assumed by the bond rotation or bond direction of the molecule, and the plurality of stereoconfigurations generated through the conformation search calculation are in the relationship of stereoisomers to each other. Conformational search calculations can be made by performing calculations using the molecular force field method using software such as CONFLEX (manufactured by Conflex) or MacroModel (manufactured by Schrödinger) to easily obtain conformational isomers. Preferred specific calculation methods are described in the Examples. Here, the number of conformations referred to in this specification is interpreted as being calculated for the skeletal structure.

In general formula (1), Ar is independently a substituted or unsubstituted aromatic hydrocarbon group with 6 to 30 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group with 3 to 24 carbon atoms, or a 2 to 10-linked aromatic ring thereof. It represents a substituted or unsubstituted connected aromatic group.

Specific examples of Ar include benzene, pentalene, indene, naphthalene, azulene, hepthalene, octalene, indacene, acenaphthylene, phenalene, phenanthrene, anthracene, trindene, fluoranthene, and acephenanthryl. Ren, aceanthrylene, triphenylene, pyrene, chrysene, tetraphene, tetracene, pleiadene, picene, perylene, pentaphene, pentacene, tetraphenylene, cholanthrylene, helicene, hexaphene, ruby. sen, coronene, trinaphthylene, heptaphene, pyranthrene, furan, benzofuran, isobenzofuran, Phenoxathiin, thionaphthene, isothianaphthene, thioptene, thiophantrene, dibenzothiophene, pyrrole, pyrazole, tellurazole, selenazole, thiazole, isothiazole, oxa Sol, furazan, pyridine, pyrazine, pyrimidine, pyridazine, triazine, indolizine, indole, indoloindole, indolocarbazole, isoindole, indazole, purine, quinolidine, isoquinoline, carbazole, Imidazole, naphthyridine, phthalazine, quinazoline, benzodiazepine, quinoxaline, cinnoline, quinoline, pteridine, phenanthridine, acridine, perimidine, phenanthroline, phenazine, carboline, phenotel Examples include groups formed by removing hydrogen from aromatic compounds such as rulazine, phenoselenazine, phenothiazine, phenoxazine, antiridine, benzothiazole, benzoimidazole, benzooxazole, benzoisoxazole, or benzoisothiazole. You can. Preferably benzene, naphthalene, anthracene, triphenylene, pyrene, pyridine, pyrazine, pyrimidine, pyridazine, triazine, carbazole, indole, indoloindole, indolocarbazole, dibenzofuran, dibenzothiophene. , a group formed by removing hydrogen from quinoline, isoquinoline, quinoxaline, quinazoline, or naphthyridine.

In General Formula (1), HetAr represents a substituted or unsubstituted aromatic heterocyclic group having 3 to 24 carbon atoms. Specific examples thereof include furan, benzofuran, isobenzofuran, xanthene, oxathrene, dibenzofuran, ferric acid theoxanthene, thiophene, dioxanthene, thianthrene, phenoxathiin, thionaphthene, Isothianaphthene, thiophthene, thiophantrene, dibenzothiophene, pyrrole, pyrazole, tellulazole, selenazole, thiazole, isothiazole, oxazole, furazan, pyridine, pyrazine, pyrimidine, Pyridazine, triazine, indolizine, indole, isoindole, indazole, purine, quinolidine, isoquinoline, carbazole, indoloindole, indolocarbazole, imidazole, naphthyridine, phthalazine, quinazoline. , benzodiazepines, quinoxaline, cinnoline, quinoline, pteridine, phenanthridine, acridine, perimidine, phenanthroline, phenazine, carboline, phenotellulazine, phenoselenazine, phenothiazine, phenoxine. Photo, antiridine, benzothiazole, benzoimidazole, benzooxazole, benzoisoxazole, or benzoisothiazole, and other groups formed by removing hydrogen from aromatic heterocyclic compounds. Preferably pyridine, pyrazine, pyrimidine, pyridazine, triazine, carbazole, indole, indoloindole, indolocarbazole, dibenzofuran, dibenzothiophene, quinoline, isoquinoline, quinoxaline, quinazoline or It is a group formed by removing hydrogen from naphthyridine. The number of hydrogens removed is z.

In General Formula (1), z represents an integer of 2 to 5, but is more preferably an integer of 2 to 4 in terms of amorphous stability and charge transport characteristics.

Preferred examples of compounds for organic electroluminescent devices of the present invention include compounds represented by the above general formula (2) or (3).

In general formula (2), ring A represents an aromatic ring represented by formula (A2) in which two adjacent rings are condensed at arbitrary positions. Ring B represents a nitrogen-containing 5-membered ring represented by the formula (B2) in which two adjacent rings are condensed at arbitrary positions.

L is independently expressed in formula (c2). Ar ¹ to Ar ⁷ each independently represent an aromatic hydrocarbon group having 6 to 24 carbon atoms or an aromatic heterocyclic group having 3 to 16 carbon atoms, and each of these aromatic hydrocarbon groups or aromatic heterocyclic groups may be independently substituted, In that case, the substituent Q is deuterium, halogen, cyano group, nitro group, alkyl group with 1 to 20 carbon atoms, aralkyl group with 7 to 38 carbon atoms, alkenyl group with 2 to 20 carbon atoms, and alkynyl group with 2 to 20 carbon atoms. , dialkylamino group with 2 to 40 carbon atoms, diarylamino group with 12 to 44 carbon atoms, dialkylamino group with 14 to 76 carbon atoms, acyl group with 2 to 20 carbon atoms, acyloxy group with 2 to 20 carbon atoms. , an alkoxy group with 1 to 20 carbon atoms, an alkoxycarbonyl group with 2 to 20 carbon atoms, an alkoxycarbonyloxy group with 2 to 20 carbon atoms, an alkylsulfonyl group with 1 to 20 carbon atoms, or a hydrogen atom in these hydrocarbon groups is deuterium. , or a group substituted with halogen.

R ¹ to R ³ each independently represent the above substituent Q or L. There may be two or more L, at least one of which has a total number of Ar ² to Ar ⁷ included in L of 4 or more. a, b, and c represent the number of substitutions, and each independently represents an integer from 0 to 2. d, e, and f represent the number of repetitions and each independently represents an integer from 0 to 5. g, h, and i represent the number of substitutions, and each independently represents an integer from 0 to 5. The total number of Ar ² to Ar ⁷ can be calculated from the numbers of e, f, g, h, and i in equation (c2).

For the compound represented by General Formula (2), the number of conformations generated by the conformation search calculation is preferably greater than 4 × 2 ⁿ and not more than 4 × 4 ^{n + 1} , more preferably 4 × 2 ⁿ . It is greater than 4×4 ⁿ and less than or equal to 4×4 n, more preferably greater than 4×2 ^{n+1 and} less than or equal to 4×4 ⁿ .

Here, n is an integer obtained by subtracting 4 from the total number of Ar ² to Ar ^7. In this case, n is preferably 1 to 7, and more preferably 2 to 5. Here, the total number of Ar ² to Ar ⁷ is interpreted as the sum of the total number of Ar ² to Ar ⁷ for each L since there are two or more L in general formula (2).

In general formula (2), Ar ¹ to Ar ⁷ represent an aromatic hydrocarbon group having 6 to 24 carbon atoms or an aromatic heterocyclic group having 3 to 16 carbon atoms, and specific examples include benzene, penthalene, indene, naphthalene, Azulene, heptalene, octalene, indacene, acenaphthylene, phenalene, phenanthrene, anthracene, trindene, fluoranthene, acephenanthrylene, aceanthrylene, triphenylene, pyrene, chrysene, tetra Phen, tetracene, pleiadene, phycene, perylene, pentaphene, pentacene, tetraphenylene, cholanthrylene, helicene, hexaphene, rubicene, coronene, trinaphthylene, heptaphene, pyranthrene, furan. , Benzofuran, Isobenzofuran, Ten, thiophantrene, dibenzothiophene, pyrrole, pyrazole, tellulazole, selenazole, thiazole, isothiazole, oxazole, furazan, pyridine, pyrazine, pyrimidine, pyridazine, triazine, indole Lysine, indole, isoindole, indazole, purine, quinolidine, isoquinoline, carbazole, imidazole, naphthyridine, phthalazine, quinazoline, benzodiazepine, quinoxaline, cinnoline, quinoline, pteridine, phenane Tridine, acridine, perimidine, phenanthroline, phenazine, carboline, phenotellulazine, phenoselenazine, phenothiazine, phenoxazine, antiridine, benzothiazole, benzoimidazole, benzoxazole , benzoisoxazole, or benzoisothiazole, a group formed by removing hydrogen from an aromatic compound. Preferably benzene, naphthalene, anthracene, triphenylene, pyrene, pyridine, pyrazine, pyrimidine, pyridazine, triazine, carbazole, indole, indoloindole, dibenzofuran, dibenzothiophene, quinoline, isoquinoline. , a group formed by removing hydrogen from quinoxaline, quinazoline, or naphthyridine.

In general formula (2), a, b, and c represent the number of substitutions and each independently represents an integer of 0 to 2, preferably an integer of 0 to 1.

d, e, and f represent the number of repetitions and each independently represents an integer of 0 to 5, preferably an integer of 0 to 4, and more preferably an integer of 0 to 3.

g, h, and i represent the number of substitutions, and each independently represents an integer of 0 to 5, preferably an integer of 0 to 4, and more preferably an integer of 0 to 2. Additionally, it is good that either d or i is an integer of 1 or more.

In general formula (3), ring C represents an aromatic ring represented by formula (C3) in which two adjacent rings are condensed at arbitrary positions. Ring D represents a nitrogen-containing 5-membered ring represented by the formula (D3) in which two adjacent rings are condensed at arbitrary positions. L has the same meaning as in general formula (2), and Ar ² in any one of L represents an i+1 valent substituted or unsubstituted aromatic heterocyclic group having 3 to 9 carbon atoms.

It is preferable that any L in general formula (3) is represented by the above formula (c5). In the formula, X each independently represents CH, C-, or nitrogen, and at least one of X represents nitrogen. Symbols common to General Formula (2), such as Ar ¹ , Ar ³ ~Ar ⁷ , d~i, etc., have the same meaning.

Additionally, it is preferable that L in general formula (2) or (3) has at least one partial structure represented by the above formula (4). By having the partial structure shown in equation (4), the number of conformations becomes a more desirable value.

It is preferable that the number of substitution i in formula (c5) in general formula (3) is 2 to 4, and the 2 to 4 substituents are different from each other. By having different substituents, symmetry is broken and more three-dimensional configurations can be assumed.

Additionally, it is preferable that L in the general formula (2) or (3) has at least two partial structures represented by the above formula (4). It is more preferable to have at least one partial structure represented by the formula (5), and it is more preferable to have at least one partial structure represented by the formula (5) on the nitrogen-containing 6-membered ring in formula (c5).

In general formula (2) or (3), Ar ¹ , Ar ³ to Ar ⁷ are preferably aromatic hydrocarbon groups having 6 carbon atoms, and the total number of Ar ¹ to Ar ⁷ is preferably 6 or more and 10 or less. .

In addition, it is preferable that any one of Ar ³ to Ar ⁷ constituting L in General Formula (2) or (3) has at least one partial structure represented by the above Formula (4) or (5).

Specific examples of compounds for organic electroluminescent devices represented by General Formula (2) are shown below, but are not limited to these exemplary compounds.

[Formula 7]

[Formula 8]

[Formula 9]

[Formula 10]

[Formula 11]

[Formula 12]

[Formula 13]

[Formula 14]

[Formula 15]

[Formula 16]

[Formula 17]

[Formula 18]

[Formula 19]

[Formula 20]

[Formula 21]

[Formula 22]

[Formula 23]

[Formula 24]

[Formula 25]

[Formula 26]

[Formula 27]

[Formula 28]

[Formula 29]

[Formula 30]

[Formula 31]

[Formula 32]

[Formula 33]

[Formula 34]

[Formula 35]

[Formula 36]

[Formula 37]

[Formula 38]

[Formula 39]

The compound for an organic electroluminescent device of the present invention can be used alone as a material for an organic electroluminescent device, but it can be used as a material for an organic electroluminescent device by using multiple compounds for an organic electroluminescent device of the present invention or by mixing it with other compounds. By doing so, its function can be improved or its missing characteristics can be further supplemented. Preferred compounds that can be mixed with the compound for an organic electroluminescent device of the present invention are not particularly limited as long as they are known compounds.

The compound or material for an organic electroluminescent device of the present invention can be used as an organic layer material such as a hole injection layer, hole transport layer, electron transport layer, electron injection layer, hole blocking layer, and electron blocking layer that constitutes an organic electroluminescent device. Among them, it is preferable to use it as a hole transport layer, electron blocking layer, light emitting layer, electron transport layer, and hole blocking layer material, and more preferably, it is used as an electron blocking layer, light emitting layer, and hole blocking layer material.

When forming a film using a material for an organic electroluminescent device by a vapor deposition process, an organic layer may be formed by vaporizing one or two or more compounds of the present invention from a vapor deposition source, or a known host material or phosphorescent material may be used. , an organic layer can be formed by depositing from another deposition source simultaneously with other compounds such as luminescent dopant materials such as fluorescence and delayed fluorescence. In addition, before deposition, two or more types of compounds of the present invention may be premixed to form a premix, and the premix may be simultaneously deposited from one deposition source to form an organic layer. In addition, one or more types of compounds of the present invention are premixed with known host materials or luminescent dopant materials such as phosphorescence, fluorescence, delayed fluorescence, etc. to form a premixture, and the premixture is deposited simultaneously from one deposition source. Thus, an organic layer can be formed. In this case, it is preferable that the temperature difference between the compound used for premixing and the compound for organic electroluminescent devices of the present invention, which achieves the desired vapor pressure, is 30°C or less.

Materials for organic electroluminescent devices can also be applied to various application processes such as spin coating, bar coating, spraying, inkjet, and printing. In this case, a solution in which the material for an organic electroluminescent device of the present invention is dissolved or dispersed in a solvent (also referred to as a composition for an organic electroluminescent device) is applied on a substrate, and then the solvent is volatilized by heating and drying to form an organic layer. can do. At this time, the solvent used may be one type, or a mixture of two or more types may be used. In addition, the solution may contain compounds other than those of the present invention, including known host materials and luminescent dopant materials such as phosphorescence, fluorescence, and delayed fluorescence, and may also contain additives such as surface modifiers and dispersants to the extent that they do not impair the properties. do.

Next, the structure of the device manufactured using the material of the present invention will be described with reference to the drawings, but the structure of the organic electroluminescent device of the present invention is not limited thereto.

1 is a cross-sectional view showing a structural example of a general organic electroluminescent device used in the present invention, where 1 is a substrate, 2 is an anode, 3 is a hole injection layer, 4 is a hole transport layer, 5 is a light emitting layer, 6 is an electron transport layer, 7 represents the cathode. The organic EL device of the present invention may have an exciton-blocking layer adjacent to the light-emitting layer, or may have an electron-blocking layer between the light-emitting layer and the hole injection layer. The exciton-blocking layer can be inserted into either the anode side or the cathode side of the light-emitting layer, and can also be inserted on both sides simultaneously. The organic electroluminescent device of the present invention has an anode, a light-emitting layer, and a cathode as essential layers. In addition to the essential layers, it is preferable to have a hole injection and transport layer and an electron injection and transport layer, and furthermore, it is better to have a hole blocking layer between the light-emitting layer and the electron injection and transport layer. good night. Meanwhile, the hole injection and transport layer refers to one or both of a hole injection layer and a hole transport layer, and the electron injection and transport layer refers to one or both of an electron injection layer and an electron transport layer.

It is also possible to have a structure opposite to that of Figure 1, that is, to stack the cathode 7, electron transport layer 6, light emitting layer 5, hole transport layer 4, and anode 2 in that order on the substrate 1. In this case as well, it is possible to add or omit layers as needed.

-Board-

The organic electroluminescent device of the present invention is preferably supported on a substrate. There are no particular restrictions on this substrate, and any substrate that has been conventionally used in organic electroluminescent devices can be used. For example, those made of glass, transparent plastic, quartz, etc. can be used.

-anode-

As an anode material in an organic electroluminescent device, a material made of a metal, alloy, electrically conductive compound, or a mixture thereof with a large work function (4 eV or more) is preferably used. Specific examples of such electrode materials include metals such as Au, CuI, indium tin oxide (ITO), SnO ₂ , and conductive transparent materials such as ZnO. Additionally, an amorphous material capable of producing a transparent conductive film, such as IDIXO (In ₂ O ₃ -ZnO), may be used. For the anode, a thin film can be formed using these electrode materials by methods such as vapor deposition or sputtering, and a pattern of the desired shape can be formed by photolithography, or in cases where pattern precision is not required (approximately 100㎛ or more) ) may form a pattern through a mask of a desired shape during deposition or sputtering of the electrode material. Alternatively, when using a coatable material such as an organic conductive compound, a wet film forming method such as a printing method or a coating method may be used. When emitting light from this anode, the transmittance is preferably greater than 10%, and the sheet resistance as the anode is preferably several hundred Ω/□ or less. The film thickness varies depending on the material, but is usually selected in the range of 10 to 1000 nm, preferably 10 to 200 nm.

-cathode-

Meanwhile, as the cathode material, a material made of a metal with a small work function (4 eV or less) (referred to as an electron-injecting metal), an alloy, an electrically conductive compound, or a mixture thereof is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium/copper mixture, magnesium/silver mixture, magnesium/aluminum mixture, magnesium/indium mixture, aluminum/aluminum oxide (Al ₂ O ₃ ) mixture, indium, lithium/aluminum mixture, rare earth metal, etc. Among these, in terms of electron injectability and durability against oxidation, mixtures of an electron injectable metal and a second metal that has a larger work function and is a more stable metal, such as magnesium/silver mixture, magnesium/aluminum mixture, magnesium/silver mixture, Indium mixtures, aluminum/aluminum oxide (Al ₂ O ₃ ) mixtures, lithium/aluminum mixtures, aluminum, etc. are suitable. The cathode can be manufactured by forming a thin film of these cathode materials by methods such as vapor deposition or sputtering. Additionally, as a cathode, the sheet resistance is preferably several hundred Ω/□ or less, and the film thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 to 200 nm. On the other hand, in order to transmit the emitted light, the luminance is improved if either the anode or the cathode of the organic electroluminescent element is transparent or translucent, and it is very suitable.

In addition, after forming the metal on the cathode to a film thickness of 1 to 20 nm, by forming the conductive transparent material mentioned in the description of the anode thereon, a transparent or translucent cathode can be manufactured, and by applying this, both the anode and the cathode can be formed. A device having this transparency can be manufactured.

-Luminous layer-

The light-emitting layer is a layer that emits light after excitons are generated by recombination of holes and electrons injected from each of the anode and cathode. The light-emitting layer includes a light-emitting dopant material and a host material.

The material for an organic electroluminescent device of the present invention is suitably used as a host material in a light-emitting layer. In addition, one or more types of known host materials may be used in combination, but the amount used is 5 wt% or more and 95 wt% or less, preferably 20 wt% or more and 80 wt% or less, relative to the total of the host materials.

Known host materials that can be used are preferably compounds that have hole transport ability and electron transport ability, prevent light emission from becoming longer wavelength, and have a high glass transition temperature.

Such other host materials are known from numerous patent documents and the like, and can be selected from them. Specific examples of the host material are not particularly limited, but include indole derivatives, carbazole derivatives, indolocarbazole derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, and pyrazoline. Derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic tertiary amine compounds, styryl Amine compounds, aromatic dimethylidene compounds, porphyrin compounds, anthraquinodimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thiopyrandioxide derivatives, heterocyclic tetracarboxylic anhydrides such as naphthalene perylene, phthalocyanine derivatives, 8 -Various metal complexes such as metal complexes of quinolinol derivatives, metal phthalocyanine, benzooxazole or benzothiazole derivatives, polysilane-based compounds, poly(N-vinylcarbazole) derivatives, aniline-based copolymers, and polymer compounds such as thiophene oligomers, polythiophene derivatives, polyphenylene derivatives, polyphenylenevinylene derivatives, and polyfluorene derivatives.

The material for an organic electroluminescent device can be deposited from an evaporation source or dissolved in a solvent to form a solution and then applied on the hole injection and transport layer and dried to form a light-emitting layer.

When forming an organic layer by depositing a material for an organic electroluminescent device, along with the material of the present invention, other host materials, and dopants may be deposited from different deposition sources, or may be premixed before deposition to form a premix from one deposition source. A plurality of host materials or dopants may be deposited simultaneously.

When forming a light-emitting layer by applying and drying a solution of a material for an organic electroluminescent device, it is preferable that the material used for the underlying hole injection and transport layer has low solubility in the solvent used in the light-emitting layer solution.

As the luminescent dopant material, any of a fluorescent dopant, a phosphorescent dopant, or a delayed fluorescent dopant may be used. In terms of luminous efficiency, a phosphorescent dopant and a delayed fluorescent dopant are preferred. Additionally, only one type of these luminescent dopants may be contained, or two or more types of dopants may be contained.

The phosphorescent dopant preferably contains an organic metal complex containing at least one metal selected from ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, and gold. Specifically, J. Am. Chem. Soc. Iridium complexes described in 2001, 123, 4304 and Japanese Patent Publication No. 2013-53051 are suitably used, but are not limited to these. Additionally, the content of the phosphorescent dopant material is preferably 0.1 to 30 wt%, more preferably 1 to 20 wt%, relative to the host material.

The phosphorescent dopant material is not particularly limited, but specific examples include the following.

[Formula 40]

[Formula 41]

When using a fluorescent dopant, the fluorescent dopant is not particularly limited, and examples include benzoxazole derivatives, benzothiazole derivatives, benzoimidazole derivatives, styrylbenzene derivatives, polyphenyl derivatives, diphenylbutadiene derivatives, Tetraphenylbutadiene derivatives, naphthalimide derivatives, coumarin derivatives, condensed aromatic compounds, perrinone derivatives, oxadiazole derivatives, oxazine derivatives, aldazine derivatives, pyrazine derivatives, cyclopentadiene derivatives, bistyryl anthracene derivatives, Quinacridone derivatives, pyrrolopyridine derivatives, thiadiazolopyridine derivatives, styrylamine derivatives, diketopyrrolopyrrole derivatives, aromatic dimethylidine compounds, metal complexes of 8-quinolinol derivatives or pyromethene derivatives, rare earths Complexes, various metal complexes represented by transition metal complexes, polymer compounds such as polythiophene, polyphenylene, and polyphenylenevinylene, and organic silane derivatives. Preferred examples include condensed aromatic derivatives, styryl derivatives, diketopyrrolopyrrole derivatives, oxazine derivatives, pyromethene metal complexes, transition metal complexes, or lanthanoid complexes, and more preferably naphthalene, pyrene, chrysene, Triphenylene, benzo[c]phenanthrene, benzo[a]anthracene, pentacene, perylene, fluoranthene, acenaphthofluoranthene, dibenzo[a,j]anthracene, dibenzo[a,h] Anthracene, benzo[a]naphthalene, hexacene, naphtho[2,1-f]isoquinoline, α-naphthaphenanthridine, phenanthrooxazole, quinolino[6,5-f]quinoline, benzothiopantrene etc. can be mentioned. These may have an alkyl group, an aryl group, an aromatic heterocyclic group, or a diarylamino group as a substituent. Additionally, the content of the fluorescent dopant material is preferably 0.1 to 20%, more preferably 1 to 10%, relative to the host material.

When using a thermally activated delayed fluorescence dopant, the thermally activated delayed fluorescence dopant is not particularly limited, but may include metal complexes such as tin complexes and copper complexes, indolocarbazole derivatives described in WO2011/070963, Nature 2012, Cyanobenzene derivatives described in 492, 234, carbazole derivatives, phenazine derivatives described in Nature Photonics 2014, 8, 326, oxadiazole derivatives, triazole derivatives, sulfone derivatives, phenoxazine derivatives, acridine derivatives, etc. You can. Additionally, the content of the thermally activated delayed fluorescence dopant material is preferably 0.1 to 90%, more preferably 1 to 50%, relative to the host material.

-Injection layer-

The injection layer is a layer provided between the electrode and the organic layer to lower the driving voltage or improve the luminance, and includes a hole injection layer and an electron injection layer, between the anode and the light-emitting layer or the hole transport layer, and between the cathode and the light-emitting layer or the electron transport layer. You can make it exist. The injection layer can be prepared as needed.

-Hole blocking layer-

In a broad sense, the hole blocking layer has the function of an electron transport layer and is made of a hole blocking material that has a function of transporting electrons but has a significantly small ability to transport holes. By blocking holes while transporting electrons, the electrons in the light emitting layer are blocked. The recombination probability of holes and holes can be improved.

The hole blocking layer preferably contains the material of the present invention, but known hole blocking layer materials can also be used.

-electron blocking layer-

In a broad sense, the electron blocking layer has the function of a hole transport layer, and can improve the probability of electrons and holes recombining in the light emitting layer by blocking electrons while transporting holes.

Known electron blocking layer materials can be used as the material for the electron blocking layer, and materials for the hole transport layer described later can also be used as needed. The thickness of the electron blocking layer is preferably 3 to 100 nm, and more preferably 5 to 30 nm.

-Egija Low Formation-

The exciton-blocking layer is a layer to prevent excitons generated by recombination of holes and electrons in the light-emitting layer from diffusing into the charge transport layer. By inserting this layer, it becomes possible to efficiently confine excitons in the light-emitting layer, causing the device to emit light. Efficiency can be improved. The exciton-blocking layer can be inserted between two adjacent light-emitting layers in a device where two or more light-emitting layers are adjacent.

As the material for the exciton blocking layer, a known exciton blocking layer material can be used. Examples include 1,3-dicarbazolylbenzene (mCP) and bis(2-methyl-8-quinolinolato)-4-phenylphenolatoaluminum(III) (BAlq).

-Hole transport layer-

The hole transport layer is made of a hole transport material that has the function of transporting holes, and the hole transport layer can be provided as a single layer or multiple layers.

The hole transport material has either hole injection or transport or electron barrier properties, and may be either organic or inorganic. For the hole transport layer, any compound among conventionally known compounds can be selected and used. Such hole transport materials include, for example, porphyrin derivatives, arylamine derivatives, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, and arylamines. derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline-based copolymers, and conductive polymer oligomers, especially thiophene oligomers. It is preferable to use porphyrin derivatives, arylamine derivatives, and styrylamine derivatives, and it is more preferable to use arylamine compounds.

-Electron transport layer-

The electron transport layer is made of a material that has the function of transporting electrons, and the electron transport layer can be provided as a single layer or multiple layers.

The electron transport material (sometimes also serves as a hole blocking material) just needs to have the function of transferring electrons injected from the cathode to the light emitting layer. For the electron transport layer, any of the conventionally known compounds can be selected and used, for example, polycyclic aromatic derivatives such as naphthalene, anthracene, and phenanthroline, tris(8-quinolinolato)aluminum(III) derivatives, and phosphatase. Pinoxide derivatives, nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyrandioxide derivatives, carbodiimide, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, bipyridine derivatives, quinoline derivatives, oxadiazole Derivatives, benzoimidazole derivatives, benzothiazole derivatives, indolocarbazole derivatives, etc. may be mentioned. In addition, polymer materials in which these materials are introduced into the polymer chain, or in which these materials are used as the main chain of the polymer, can also be used.

Example

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples and can be implemented in various forms without exceeding the gist thereof.

Conformation search calculations were performed on compounds 300, 122, 337, 338, 335, 339, 019, 600, 161, 181, and 160 exemplified as compounds for organic electroluminescent devices, and compounds 1 to 10 for comparison. For the conformation search calculation, enter the atomic coordinates and bonding form of the structure to be calculated into the calculation software called CONFLEX (manufactured by Conflex), set the conformation search range from the locally stable structure to 20 kcal/mol, and then use the molecular dynamics method ( Force field: calculated by MMFF94s). Table 1 shows the calculation results of the conformation generated by the conformation search calculation. On the other hand, all of the above compounds have a structure in which aromatic rings are linked and do not have a non-aromatic substituent, so the compounds themselves have a skeletal structure that does not contain a substituent.

Compound numbers correspond to the numbers assigned to the above exemplary compounds and the numbers assigned to the compounds for comparison below.

[Formula 42]

Additionally, the results of a solubility test in toluene for the above compounds are shown in Table 1. In the solubility test, toluene was added so that each compound had a concentration of 1 wt%, and it was ultrasonically stirred for 15 minutes in a water bath at a temperature of 40°C, and then judged by the presence or absence of any remaining dissolved substances. In the solubility test, A means there is nothing left to dissolve, and B means there is something left to dissolve.

Example 12

Each thin film was laminated by vacuum deposition at a vacuum degree of 4.0×10 ^-5 Pa on a glass substrate on which an anode made of ITO with a film thickness of 110 nm was formed. First, HAT-CN was formed to a thickness of 25 nm as a hole injection layer on ITO, and then NPD was formed to a thickness of 30 nm as a hole transport layer. Next, HT-1 was formed to a thickness of 10 nm as an electron blocking layer. Then, compound 300 as a host and Ir(ppy) ₃ as a light-emitting dopant were co-deposited from different deposition sources, and a light-emitting layer was formed with a thickness of 40 nm. At this time, co-deposition was performed under deposition conditions where the concentration of Ir(ppy) ₃ was 10 wt%. Next, ET-1 was formed to a thickness of 20 nm as an electron transport layer. Additionally, lithium fluoride (LiF) was formed to a thickness of 1 nm as an electron injection layer on the electron transport layer. Finally, aluminum (Al) was formed to a thickness of 70 nm as a cathode on the electron injection layer, and an organic EL device was manufactured.

Examples 13-18

In Example 12, an organic EL device was produced in the same manner as in Example 12, except that any one of compounds 122, 019, 600, 161, 181, or 160 was used as the host.

Comparative Examples 11 to 13

In Example 12, an organic EL device was produced in the same manner as in Example 12, except that either compound 1, 2, or 3 was used as a host.

When the organic EL devices manufactured in Examples 12 to 18 and Comparative Examples 11 to 13 were connected to an external power source and a direct current voltage was applied, an emission spectrum with a maximum wavelength of 530 nm was observed in all of them, and Ir(ppy) ₃ It was found that light emission from was obtained.

Table 2 shows the luminance, driving voltage, and luminance half-life of the fabricated organic EL device.

In Tables 2 to 7, voltage, luminance, current efficiency, and power efficiency are values at a driving current of 20 mA/cm2 and are initial characteristics. LT90 is the time it takes for the luminance to decay to 90% of the initial luminance when the initial luminance is 9000㏅/m2, and is a lifespan characteristic. Meanwhile, any characteristics (voltage, luminance, LT90) are expressed as relative values with the characteristics of the standard comparative example (Comparative Example 11 in Table 2) being set as 100%.

Example 19

Each thin film was laminated by vacuum deposition at a vacuum degree of 4.0×10 ^-5 Pa on a glass substrate on which an anode made of ITO with a film thickness of 110 nm was formed. First, HAT-CN was formed to a thickness of 25 nm as a hole injection layer on ITO, and then NPD was formed to a thickness of 30 nm as a hole transport layer. Next, HT-1 was formed to a thickness of 10 nm as an electron blocking layer. Then, Compound 338 as a host and Ir(ppy) ₃ as a light-emitting dopant were co-deposited from different deposition sources, and a light-emitting layer was formed with a thickness of 40 nm. At this time, co-deposition was performed under deposition conditions where the concentration of Ir(ppy) ₃ was 10 wt%. Next, ET-1 was formed to a thickness of 20 nm as an electron transport layer. Additionally, lithium fluoride (LiF) was formed to a thickness of 1 nm as an electron injection layer on the electron transport layer. Finally, aluminum (Al) was formed to a thickness of 70 nm as a cathode on the electron injection layer, and an organic EL device was manufactured.

Example 20, Comparative Examples 14-15

In Example 19, an organic EL device was produced in the same manner as in Example 19, except that one of Compound 337, Compound 4, and Compound 5 was used as the host.

When the organic EL devices manufactured in Examples 19 to 20 and Comparative Examples 14 to 15 were connected to an external power source and a direct current voltage was applied, an emission spectrum with a maximum wavelength of 530 nm was observed in all of them, and Ir(ppy) ₃ It was found that light emission from was obtained.

Table 3 shows the characteristics of the fabricated organic EL device. The standard comparative example is Comparative Example 14.

Example 21

Each thin film was laminated by vacuum deposition at a vacuum degree of 4.0×10 ^-5 Pa on a glass substrate on which an anode made of ITO with a film thickness of 110 nm was formed. First, HAT-CN was formed to a thickness of 25 nm as a hole injection layer on ITO, and then NPD was formed to a thickness of 30 nm as a hole transport layer. Next, HT-1 was formed to a thickness of 10 nm as an electron blocking layer. Then, Compound 335 as a host and Ir(ppy) ₃ as a light-emitting dopant were co-deposited from different deposition sources, and a light-emitting layer was formed with a thickness of 40 nm. At this time, co-deposition was performed under deposition conditions where the concentration of Ir(ppy) ₃ was 10 wt%. Next, ET-1 was formed to a thickness of 20 nm as an electron transport layer. Additionally, lithium fluoride (LiF) was formed to a thickness of 1 nm as an electron injection layer on the electron transport layer. Finally, aluminum (Al) was formed to a thickness of 70 nm as a cathode on the electron injection layer, and an organic EL device was manufactured.

Comparative Example 16

In Example 21, an organic EL device was produced in the same manner as in Example 21 except that Compound 6 was used as the host.

When an external power source was connected to the organic EL devices manufactured in Example 21 and Comparative Example 16 and a direct current voltage was applied to them, emission spectra with a maximum wavelength of 530 nm were observed in both cases, and light emission from Ir(ppy) ₃ was observed. I was able to see what was achieved.

Table 4 shows the characteristics of the fabricated organic EL device. The standard comparative example is Comparative Example 16.

Example 22

Each thin film was laminated by vacuum deposition at a vacuum degree of 4.0×10 ^-5 Pa on a glass substrate on which an anode made of ITO with a film thickness of 110 nm was formed. First, HAT-CN was formed to a thickness of 25 nm as a hole injection layer on ITO, and then NPD was formed to a thickness of 30 nm as a hole transport layer. Next, HT-1 was formed to a thickness of 10 nm as an electron blocking layer. Then, Compound 339 as a host and Ir(ppy) ₃ as a light-emitting dopant were co-deposited from different deposition sources, and a light-emitting layer was formed with a thickness of 40 nm. At this time, co-deposition was performed under deposition conditions where the concentration of Ir(ppy) ₃ was 10 wt%. Next, ET-1 was formed to a thickness of 20 nm as an electron transport layer. Additionally, lithium fluoride (LiF) was formed to a thickness of 1 nm as an electron injection layer on the electron transport layer. Finally, aluminum (Al) was formed to a thickness of 70 nm as a cathode on the electron injection layer, and an organic EL device was manufactured.

Comparative Example 17

In Example 22, an organic EL device was produced in the same manner as in Example 22 except that Compound 7 was used as the host.

When an external power source was connected to the organic EL devices manufactured in Example 22 and Comparative Example 17 and a direct current voltage was applied to them, emission spectra with a maximum wavelength of 530 nm were observed in all cases, and light emission from Ir(ppy) ₃ was observed. I was able to see what was achieved.

Table 5 shows the characteristics of the fabricated organic EL device. The standard comparative example is Comparative Example 17.

Example 27

Poly(3,4-ethylenedioxythiophene)/polystyrenesulfonic acid (PEDOT/PSS) as a hole injection layer on a glass substrate with ITO having a film thickness of 150 nm that has been washed with solvent and treated with UV ozone: (H. C. Stark) (trade name: Creviose PCH8000, manufactured by K.A. Co., Ltd.) was deposited into a film with a thickness of 25 nm. Next, the mixture mixed at a ratio of HT-2:BBPPA=5:5 (molar ratio) was dissolved in tetrahydrofuran to prepare a 0.4 wt% solution, and a 20 nm film was formed by spin coating. Next, the solvent was removed on a hot plate at 150°C for 1 hour under anaerobic conditions, followed by heating and curing. This thermosetting film has a cross-linked structure and is insoluble in solvents. This thermosetting film is a hole transport layer (HTL). Then, using compound 300 as a host and Ir(ppy) ₃ as a light-emitting dopant, a toluene solution (1.0 wt%) with a host:dopant ratio of 95:5 (weight ratio) was prepared, and 40% as a light-emitting layer by spin coating. ㎚ was unveiled. Afterwards, using a vacuum deposition device, Alq ₃ was formed to a thickness of 35 nm and LiF/Al as a cathode was formed to a film thickness of 170 nm, and the device was sealed in a glove box to produce an electroluminescent device.

Examples 28-29, Comparative Example 20

In Example 27, an organic EL device was produced in the same manner as in Example 27 except that Compound 160, 122, or 1 was used as the host.

When the organic EL devices manufactured in Examples 27 to 29 and Comparative Example 20 were connected to an external power source and a direct current voltage was applied, an emission spectrum with a maximum wavelength of 530 nm was observed in each case, and the emission spectrum from Ir(ppy) ₃ was observed. It was found that luminescence was obtained.

Table 6 shows the characteristics of the fabricated organic EL device. Meanwhile, the standard comparative example is Comparative Example 20.

From the above results, it can be seen that when a compound having a conformational number within a specific range is used as a host, the lifespan characteristic is significantly extended compared to when a compound having a conformational number outside the range is used as a host.

The compounds used in the examples are shown below.

[Formula 43]

Examples 35-36, Comparative Examples 22-23

An organic thin film was formed by depositing any one of Compounds 300 and 122, which are materials for an organic electroluminescent device of the present invention, and Comparative Compounds 1 and 2, on a silicon substrate by vacuum deposition. The substrate on which this organic thin film was formed was heated to the glass transition temperature of the material in a nitrogen atmosphere for 24 hours, and then the amorphous stability was evaluated by visual observation of the thin film and measurement of out-of-plane X-ray diffraction. .

The results of amorphous stability evaluated in Examples 35 to 36 and Comparative Examples 22 to 23 are shown in Table 7. In the state of a thin film, C indicates crystallization and A indicates non-crystallization. In addition, the XRD measurement results after heating of Example 35 and Comparative Example 22 are shown in FIG. 2. Example 35 is shown with a solid line, and Comparative Example 22 is shown with a dotted line.

From the above results, it was observed that the thin film of the comparative compound was crystallized after heating, but the thin film of the organic electroluminescent device material of the present invention showed no crystallization even after heating, and it was confirmed that the amorphous stability was high.

An organic electroluminescent device using the compound for an organic electroluminescent device of the present invention has excellent luminescence characteristics and excellent lifespan characteristics.

1: substrate
2: anode
3: Hole injection layer
4: Hole transport layer
5: Light-emitting layer
6: Electron transport layer
7: cathode

Claims (10)

A compound for an organic electroluminescent device that satisfies General Formula (2) and is selected from the group consisting of the following compounds 002, 004, 005, 014, 016, 017, 019, and 160.
[Formula 1]

Here, ring A represents an aromatic ring represented by the formula (A2) in which two adjacent rings are condensed at an arbitrary position. Ring B represents a nitrogen-containing 5-membered ring represented by the formula (B2) in which two adjacent rings are condensed at arbitrary positions.
L is independently a substituted or unsubstituted aromatic group or a connected aromatic group represented by formula (c2), Ar ¹ to Ar ⁷ are each independently, Ar ¹ , Ar ³ and Ar ⁵ are divalent, and Ar ² is i. +1-valent, Ar ⁴ is h+1-valent, Ar ⁶ is g+1-valent, and Ar ⁷ is a monovalent aromatic hydrocarbon group with 6 to 24 carbon atoms, or an aromatic heterocyclic group with 3 to 16 carbon atoms, and these aromatic The hydrocarbon group or aromatic heterocyclic group may each independently have a substituent Q, and when it has a substituent, the substituent Q may be deuterium, halogen, cyano group, nitro group, alkyl group with 1 to 20 carbon atoms, or 7 to 38 carbon atoms. Aralkyl group, alkenyl group with 2 to 20 carbon atoms, alkynyl group with 2 to 20 carbon atoms, dialkylamino group with 2 to 40 carbon atoms, diarylamino group with 12 to 44 carbon atoms, dialkyl with 14 to 76 carbon atoms Amino group, acyl group with 2 to 20 carbon atoms, acyloxy group with 2 to 20 carbon atoms, alkoxy group with 1 to 20 carbon atoms, alkoxycarbonyl group with 2 to 20 carbon atoms, alkoxycarbonyloxy group with 2 to 20 carbon atoms , an alkylsulfonyl group having 1 to 20 carbon atoms, or a group in which the hydrogen atom in these hydrocarbon groups is substituted with deuterium or halogen.
R ¹ to R ³ each independently represent a substituent Q or L.
At least one of L has a total number of Ar ² to Ar ⁷ of 4 or more, Ar ² in L is an aromatic heterocyclic group having 3 to 9 carbon atoms, and i is an integer of 1 to 5. And the sum of the numbers Ar ¹ to Ar ⁷ included in all L is 6 or more and 10 or less.
a, b, and c represent the number of substitutions, and each independently represents an integer from 0 to 2. d, e, and f represent the number of repetitions, d represents 0, and e and f each independently represent an integer from 0 to 5. g, h, and i represent the number of substitutions, and each independently represents an integer from 0 to 5.


According to paragraph 1,
A compound for an organic electroluminescent device having a solubility in toluene of 1% or more at 40°C. A material for an organic electroluminescent device comprising at least one type of the compound for an organic electroluminescent device according to claim 1 or 2. An organic electroluminescent device comprising an organic layer made of the material for organic electroluminescent devices according to claim 3. A composition for an organic electroluminescent device obtained by dissolving or dispersing the material for an organic electroluminescent device according to claim 3 in a solvent. An organic electroluminescent device comprising an organic layer made of a coating film of the composition for an organic electroluminescent device according to claim 5. According to paragraph 4,
The organic electroluminescent device includes at least one layer selected from a light emitting layer, a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a hole blocking layer, and an electron blocking layer, and at least one of the at least one layer is An organic electroluminescent device that is an organic layer. In clause 7,
The organic electroluminescent device includes a light-emitting layer, and the light-emitting layer is the organic layer. According to clause 8,
An organic electroluminescent device characterized in that the light-emitting layer contains a light-emitting dopant material. According to clause 9,
An organic electroluminescent device, characterized in that the light-emitting layer further includes at least one of carbazole derivatives as a host material.