JP2001106678A - New heterocyclic ring-containing arylamine compound and organic electroluminescent element using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an organic electroluminescent element high in light emission efficiency and emission luminance, excellent in film formability, and excellent in both durability and preservation stability under continuous driving as well, and to obtain an arylamine compound with relatively high molecular weight to be used for the above electroluminescent element. SOLUTION: This new heterocyclic ring-contg. arylamine compound >=750 in molecular weight is shown by general formula (1). The other objective organic electroluminescent element is obtained using the above arylamine compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel heterocyclic-containing arylamine compound and an organic electroluminescent device using the same (hereinafter sometimes abbreviated as an organic EL device).

[0002]

BACKGROUND OF THE INVENTION Organic E
The L element has attracted attention as an element for realizing a large-area display element driven by low voltage. An element structure in which organic layers having different carrier transport properties are laminated is effective for increasing the efficiency of the element, and a two-layer element having a hole transport layer and an electron transport light emitting layer has been reported [C. W. Tang et al, Appl. Ph
ys. Lett. , 51, p. 913 (1987)].
In this device, 1000 cd / m at an applied voltage of 10 V or less.
² has high luminance sufficient for practical use. Until now, various organic compounds have been tried as materials used for the respective layers. For example, an arylamine compound is used as a hole transporting material, and a quinolinol derivative [C.
W. Tang et al, Appl. Phys. Le
tt. , 51, p. 913 (1987)], oxadiazole derivatives [Hamada et al., The Chemical Society of Japan. p. 1540
(1991)], a triazole derivative [J. Kido
et al, Chem. Lett. , P. 47 (199
It has been reported that organic compounds containing a heterocycle such as 6)] are effective.

[0003] However, many organic compounds which have been conventionally studied have a small molecular weight, for example, 400 to 600. Therefore, during continuous driving or storage at a high environmental temperature, the organic compound is recrystallized or agglomerated due to aggregation. Deterioration is a problem. For this reason, even an element having good initial characteristics is not suitable for use for a long time, and has a shortcoming that the driving element life is about several thousand hours, which is shorter than that of an existing inorganic light emitting element, for example, a light emitting diode.

As described above, a material having excellent initial characteristics, but having a short element life is represented by the following formula:

Embedded image And a hole transporting arylamine compound (TPD).
This compound has a small ionization potential of 5.4 eV and has been widely used as a hole transport layer in an organic EL device. However, the compound has a small molecular weight of 516 and crystallizes due to Joule heat during continuous driving and environmental temperature during storage. It has been reported that the device deteriorates [E. M. Han et a
1, Chem. Lett. , P. 969 (199
4)].

[0005] In addition, when perylene, which emits blue fluorescence and has a high fluorescence quantum yield, acts as a luminescence center when used as a dopant in a very small amount in the light-emitting layer of an organic EL device, it has a small molecular weight, but has a small molecular weight. It has been reported that the fluorescence quantum yield decreases due to heat diffusion and aggregation during driving, resulting in a reduction in device efficiency and device degradation [S. A. Van Slyke et al, Ex
tended Abstracts, The 8th
International Workshopon E
electroluminescence, August
13-15, Berlin, p. 195 (199
6)].

On the other hand, the following equation

Embedded image It has been reported that the relatively high molecular weight arylamine compound represented by the formula (1) not only functions well as a hole transport layer but also has excellent thermal stability [Adachiet]
al, Appl. Phys. Lett. , 66, p.
2679 (1995)].

Further, 1,3,4-oxadiazoles function as an electron transporting layer or a light emitting layer, but those having a low molecular weight have a problem that the element is rapidly deteriorated due to crystallization [Ad
Achi et al, Appl. Phys. Let
t. , 55, p. 1489 (1989)]. However, it has been shown that thermal stability can be imparted also by increasing the molecular weight in this case [Hamada et al., Journal of the Chemical Society of Japan. p. 1
540 (1991)].

As described above, when an organic compound having a small molecular weight is used as an element constituting material, there is a problem that the element is deteriorated due to crystallization or aggregation, and stability in an amorphous state or safety in a dispersed state is caused. There is a demand for the development of a new organic material having excellent performance.

However, the functional dye molecule needs to have a planar structure, and it is not only necessary to blindly polymerize the functional dye molecule. When a device is manufactured by thinning the thin film, a uniform and smooth pinhole-free structure is obtained. The formation of a thin film is required. From such a point, production of a dense amorphous film is a very important problem in producing a high-performance organic EL device. Therefore, in order to produce a stable amorphous film, not only high thermal stability but also stable film formability and smoothness are indispensable.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems by providing high luminous efficiency, high luminous brightness, excellent film-forming properties, durability during continuous driving and stable storage. Another object of the present invention is to provide an organic electroluminescent device having excellent properties and an arylamine compound having a relatively large molecular weight used therein.

[0011]

Means for Solving the Problems Accordingly, the present inventors have:
In order to solve the above problems, attention is focused on arylamine compounds having excellent film formability, hardly causing crystallization and aggregation, and having high film stability and a relatively high molecular weight, and introducing heterocyclic units into various arylamine compounds. Intensive study was conducted to give high fluorescence. As a result, these relatively high-molecular-weight heterocyclic-containing arylamine compounds have a stable amorphous state and are excellent in thermal stability,
The present inventors have found that they function well as a hole transport layer and a light emitting layer of an organic EL device, exhibit high luminous efficiency and luminous brightness, and are extremely effective in improving the stability of the device, and have completed the present invention.

That is, the present invention provides the following general formula (1)

Embedded image (Wherein, Ar ¹ is a heterocyclic group which may have a substituent, may form a condensed ring with a benzene ring to which Ar ¹ is bonded, and R ^{1 to} R ¹⁶ are A group independently selected from the group consisting of a hydrogen atom, an amino group, an alkyl group, an alkoxy group and an aryl group which may have a substituent, and Ar ^{2 to} Ar ⁵ may have a substituent. A heterocyclic ring-containing arylamine compound having a molecular weight of 750 or more, which is independently selected from the group consisting of aryl groups.

The heterocycle may be a heteromonocycle or a fused heterocycle. Examples of the substituent that can be bonded to the heterocyclic ring include an amino group, a cyano group, a hydroxyl group, an alkyl group, a halogen-substituted alkyl group, an aryl group, an alkyloxycarbonyl group, an aryloxycarbonyl group, an alkylcarbonyl group, and an arylcarbonyl group. Group, alkylamino group and the like.

In the above general formula (1)

Embedded image But,

Embedded image

Embedded image (Wherein R ²¹ , R ²² , R ²⁴ and R ²⁶ are hydrogen,
R ²³ is a group independently selected from the group consisting of an alkyl group having 1 to 4 carbon atoms and an alkoxy group having 1 to 4 carbon atoms, and R ²³ is a group consisting of fluorine and a halogenated alkyl group having 1 to 2 carbon atoms. R ²⁵ is a methylene group or an ethylene group. ) Can be a group selected from the group consisting of:

In the general formula (1)

Embedded image May be a skeletal structure serving as a luminescent center in a luminescent compound containing a hole-transporting heterocyclic ring.
In general, an organic compound having a high fluorescence quantum yield contains a heterocyclic unit (Organic Luminescence).
t Materials, B .; M. Krasovits
kii and B. M. Bolotin, VCH, 1
988), organic compounds of this type are already used in fluorescent dyes, laser dyes, and optical brighteners. A hole transporting property can be imparted by bonding an arylamine unit to the skeleton structure serving as the luminescent center of these luminescent compounds.

Specific examples of the light emitting compound include, for example, coumarin-1, coumarin-6, coumarin-7, coumarin-138, coumarin-152, coumarin-314, coumarin-334, coumarin-337, coumarin-343,
Coumarin-DHBP, 3- [2- (diethylamino) ethyl] -7-hydroxy-4-methyl-coumarin, DC
M, DCN-q and the like.

The skeleton structures serving as luminescent centers in these luminescent compounds have the following formulas:

Embedded image

Embedded image Which are represented by the formula

Embedded image This corresponds to the group represented by.

The organic electroluminescent device of the present invention is not particularly limited in its device structure as long as it has an organic layer containing a heterocyclic-containing arylamine compound. The above multi-layer type may be used. In short, the present invention can be an organic EL device having various device structures provided with the above-described heterocyclic-containing arylamine compound. The thickness of each layer constituting the device containing the high molecular weight heterocyclic-containing arylamine compound is not particularly limited in the present invention. The organic layer is formed by a vapor phase growth method such as a vacuum evaporation method or a solution coating method.

In an organic electroluminescent device, holes are injected into an organic layer from an anode having a large work function, that is, a hole injection electrode, and electrons are injected into an organic layer from a cathode electrode having a small work function. In the case of a two-layer device comprising a hole transporting layer and an electron transporting light emitting layer, the injected holes recombine with the electrons injected into the light emitting layer near the interface with the light emitting layer through the hole transporting layer. Exciton is generated in the light emitting layer. As a result, light is emitted from the light emitting layer. At this time,
Since Joule heat is generated by energization, recrystallization and aggregation of the organic layer may be promoted. Therefore, it is necessary to select a material having a high glass transition point in order to prevent device deterioration, and the compound of the present invention sufficiently satisfies this requirement.

For reference, examples of the heterocyclic-containing arylamine compound of the present invention are shown below.

Embedded image

[0021]

Embedded image

[0022]

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[0023]

Embedded image

[0024]

Embedded image

[0025]

Embedded image

[0026]

Embedded image

[0027]

Embedded image

[0028]

Embedded image

One example of the method for producing the heterocyclic-containing arylamine compound of the present invention is shown below.

Embedded image

[0030]

EXAMPLES The present invention will be described below with reference to examples.
The present invention is not limited thereby.

Example 1 Part 1 <Synthesis of [4- (4-iodophenyl) phenyl] -diphenylamine (IBD)> 5.9 g (35 mmol) of diphenylamine, 4,4 ′
-Diiodobiphenyl 8.8 g (20 mmol), activated copper 18.3 g (300 mmol), potassium carbonate 6.7
g (50 mmol) and added at 230 ° C. in a nitrogen atmosphere.
Refluxed for 2 hours. After the reaction, tetrahydrofuran (TH
Extraction with F), filtration to remove copper, purification by column chromatography using chloroform: hexane = 1: 3 as a mixed solvent, recovery of the target compound as crude white crystals, and recrystallization with methanol Purification was performed to obtain needle crystals. The reaction formula is shown below [Tetr
ahedron Letters 39 (1998) 23
67-2370]. Yield: 16.8% Melting point: 118.3-119.1 ° C

2 <Bis {4- [4- (diphenylamino) phenyl] phenyl} 4- (5-methylbenzothiazol-2-yl) phenyl} amine (DABAP
Synthesis of MB)> IBD 0.85 g (2 mmol), 2- (4-aminophenyl) -6-methylbenzothiazole 0.24 g (1
mmol), 0.06 g (10 mmol) of active copper and 0.35 g (2 mmol) of potassium carbonate, and the mixture was refluxed at 230 ° C. for 24 hours under a nitrogen atmosphere. After the reaction, the mixture was extracted with THF, filtered to remove copper, and toluene: hexane =
Purification was performed by column chromatography using 3: 1 as a mixed solvent, and the crude crystals were collected and washed with acetone for about 1 hour with stirring. The reaction formula is shown below collectively. The IR spectrum of the compound (DABAPMB) in FIG. ^{1, 1}
The H-NMR spectrum is shown in FIG. Yield: 35.7% Melting point: 157.9-159.1 ° C

[0033]

Embedded image

Example 2 1 <9- {4- (4-bromophenyl) phenyl}
Synthesis of carbazole (BBC)> 0.28 g (1.25 mmol) of palladium (II) acetate
l), 1.01 g of tri-tert-butylphosphine
(5 mmol) was reacted in o-xylene under a nitrogen stream to produce a complex salt catalyst. Then, 15.6 g (50 mmol) of dibromobiphenyl, 8.3 of carbazole.
6 g (50 mmol) and 5.77 g (60 mmol) of sodium tert-butylate were added, and the mixture was reacted at an oil bath temperature of 130 ° C. for 24 hours. After the completion of the reaction, the mixture was extracted with chloroform and washed with water. Purification was performed by column chromatography (chloroform: n-hexane = 1: 3), followed by recrystallization purification using acetone to obtain white crystals. The reaction formula is shown below collectively. Yield: 16.1%

The 2 <bis [4- (4-carbazole-
9-yl-phenyl) phenyl] [4- (5-methylbenzothiazol-2-yl) phenyl] amine (CzB
Synthesis of APMB)> 0.03 g of palladium (II) acetate (0.15 mmol)
l), 0.12 g of tri-tert-butylphosphine
(0.6 mmol) was reacted in o-xylene under a nitrogen stream to produce a complex salt catalyst. Then, 9- ｛4-
(4-bromophenyl) phenyl} carbazole (BB
C) 2.39 g (6 mmol), 2- (4-aminophenyl) -6-methylbenzothiazole 0.72 g (3 m
mol), 0.7 g of sodium tert-butyrate
(7.2 mmol), and the temperature of the oil bath was set to 130.
C. and reacted for 24 hours. After the completion of the reaction, the mixture was extracted with chloroform and washed with water. Purification is performed by column chromatography (chloroform: n-hexane = 1: 2) to recover a yellow-white solid, and sublimation purification (nitrogen flow rate 50 cc / min, heater temperature 390 ° C .; 195 ° C.)
Was carried out to obtain a yellow target substance. The reaction formula is shown below collectively. FIG. 3 shows an IR spectrum and FIG. 4 shows a ¹ H-NMR spectrum of the compound of the present invention (CzBAPMB). Yield: 44.9% Melting point: 190.5-192.0 ° C

[0036]

Embedded image

Example 3 1 <Synthesis of 2,7-dibromo-9,9-diethylfluorene (DBDEF)> The synthesis of this compound is described in Chem. Mate
r. , 10 (7), 1863-1874, (1998).
Synthesized by the following method. Yield: 78% m. p. 157.5-159.0 ° C

The 2 <9- (7-bromo-9,9-diethylfluoren-2-yl) carbazole (CzBDE
Synthesis of F)> 0.28 g (1.25 mmol) of palladium (II) acetate
l), 1.01 g of tri-tert-butylphosphine
(5 mmol) was reacted in o-xylene under a nitrogen stream to produce a complex salt catalyst. Then, 2,7-dibromo-9,9-diethylfluorenone (DBDEF) 1
9.0 g (50 mmol), carbazole 8.36 g
(50 mmol) and 5.77 g (60 mmol) of sodium tert-butylate were added, and the temperature of the oil bath was set to 130 ° C., and the reaction was performed for 24 hours. After the completion of the reaction, the mixture was extracted with chloroform and washed with water. Purification was performed by column chromatography (chloroform: n-hexane = 1: 1).
3), followed by recrystallization purification using acetone to obtain white crystals. The reaction formula is shown below collectively.
Yield: 14.8%

The 3 <bis (7-carbazol-9-yl-9,9-diethylfluoren-2-yl) [4-
(5-methylbenzothiazol-2-yl) phenyl]
Synthesis of amine (CzBEFPMB)> 0.03 g (0.15 mmol) of palladium (II) acetate
l), 0.12 g of tri-tert-butylphosphine
(0.6 mmol) was reacted in o-xylene under a nitrogen stream to produce a complex salt catalyst. Then, 2- (7-
Bromo-9,9-diethylfluorenyl) carbazole (CzBDEF) 2.8 g (6 mmol), 2- (4-
Aminophenyl) -6-methylbenzothiazole 0.7
2 g (3 mmol) and 0.7 g (7.2 mmol) of sodium tert-butylate were added, and the temperature of the oil bath was set to 130 ° C., and the reaction was performed for 24 hours. After the reaction,
Extracted with chloroform and washed with water. Purification was performed by column chromatography (chloroform: n-hexane =
1: 2), and a yellow-white solid was recovered and purified by sublimation (nitrogen flow rate 50 cc / min, heater temperature 390 ° C .; 1
95 ° C.) to obtain a yellow target substance. The reaction formula is shown below collectively. Yield: 36.7% Melting point:> 300 ° C

[0040]

Embedded image

Example 4 Part 1 <(7-bromo-9,9-diethylfluorene-
Synthesis of 2-yl) diphenylamine (BDEFDP)> 0.28 g of palladium (II) acetate (1.25 mmol)
l), 1.01 g of tri-tert-butylphosphine
(5 mmol) was reacted in o-xylene under a nitrogen stream to produce a complex salt catalyst. Then, 2,7-dibromo-9,9-diethylfluorenone (DBDEF) 1
9.0 g (50 mmol), diphenylamine 0.85
g (50 mmol) and 5.77 g (60 mmol) of sodium tert-butylate were added, and the temperature of the oil bath was set to 130 ° C., and the reaction was performed for 24 hours. After the reaction,
Extracted with chloroform and washed with water. Purification was performed by column chromatography (chloroform: n-hexane =
1: 3), followed by recrystallization purification using acetone to obtain white crystals. The reaction formula is shown below collectively. Yield: 19.6%

2 <bis [7- (diphenylamino)
-9,9-diethylfluoren-2-yl] [4- (6
-Methyl (benzothiazol-2-yl) phenyl] amine (DPEFRPMB)> 0.03 g (0.15 mmol) of palladium (II) acetate
l), 0.12 g of tri-tert-butylphosphine
(0.6 mmol) was reacted in o-xylene under a nitrogen stream to produce a complex salt catalyst. Then, 2.8 g (6 mmol) of (7-bromo-9,9-diethylfluoren-2-yl) diphenylamine (BDEFDP),
0.72 g (3 mmol) of-(4-aminophenyl) -6-methylbenzothiazole, sodium-tert-
0.7 g (7.2 mmol) of butyrate was added, and the temperature of the oil bath was set to 130 ° C., and the reaction was performed for 24 hours. After the completion of the reaction, the mixture was extracted with chloroform and washed with water. Purification is performed by column chromatography (chloroform: n-hexane = 1: 2), a yellow-white solid is recovered, and sublimation purification (nitrogen flow rate 50 cc / min, heater temperature 390).
° C; 195 ° C) to obtain a yellow target substance. The reaction formula is shown below collectively. Yield: 45.2% Melting point:> 300 ° C

[0043]

Embedded image

Example 5 <Production of EL Element> (In the case of doping 5% by weight of DABAPMB obtained in Example 1) FIG. 5 is a sectional view of this example. ITO (indium-tin-) with a sheet resistance of 15Ω / □ on a glass substrate
(Oxide) at 1000 °. Next, the hole transporting agent TPD ([Chemical Formula 6] of [0004]) was added to 1.0 × 10
Vacuum deposit to a thickness of 400 ° at ^-6 Torr. From there, the following equation

Embedded image And the DABAP obtained in Example 1.
MB was co-evaporated (to a 95: 5 weight percent ratio) to form a 150 ° thick luminescent layer. Further, as an electron transport layer, ZnOXD was deposited at 450 ° C., 1 × 10 ⁻⁶ T
Vapor deposition was performed under a vacuum of orr, and finally Mg and Ag (10: 1) were co-deposited at the same degree of vacuum to a thickness of 2000 mm as a cathode electrode. The light emitting region was a square having a length of 0.5 cm and a width of 0.5 cm. In the organic electroluminescent device thus manufactured, ITO was used as an anode, and Mg: Ag was used.
Was used as a cathode, a DC voltage was applied, and light emission was observed through a glass substrate. The brightness was measured by a Topcon brightness meter BM-8. This element is light blue (481 n
m) was obtained, and the emission spectrum
It was confirmed that BAPMB emitted light. Brightness is 15
V showed a high value of 4100 cd / m ² . FIG. 6 shows the luminance-voltage characteristics of the obtained organic EL device.

Example 6 (When DABAPMB is doped at 10 wt%)
A device was fabricated in the same manner as in Example 5, except that nOXD and DABAPMB were co-evaporated so as to have a weight percentage ratio of 90:10. This element is light blue (48
1 nm) was obtained, and it was confirmed from the emission spectrum that DABAPMB in the light emitting layer was emitting light. The luminance showed a high value of 6200 cd / m ^{2 at} 14 V. FIG. 6 shows the luminance-voltage characteristics of the obtained organic EL device.

Example 7 (When DABAPMB is doped at 20 wt%)
A device was produced in the same manner as in Example 5, except that nOXD and DABAPMB were co-evaporated so as to have a weight percentage ratio of 80:20. This element is light blue (48
1 nm) was obtained, and it was confirmed from the emission spectrum that DABAPMB in the light emitting layer was emitting light. The luminance showed a high value of 8300 cd / m ^{2 at} 14 V. FIG. 6 shows the luminance-voltage characteristics of the obtained organic EL device.

Example 8 (When DABAPMB is doped at 30 wt%)
A device was produced in the same manner as in Example 5, except that nOXD and DABAPMB were co-evaporated so as to have a weight percentage ratio of 70:30. This element is light blue (48
1 nm) was obtained, and it was confirmed from the emission spectrum that DABAPMB in the light emitting layer was emitting light. The luminance showed a high value of 10800 cd / m ^{2 at} 14 V. FIG. 6 shows the luminance-voltage characteristics of the obtained organic EL device.

Example 9 (When DABAPMB is doped at 40 wt%)
A device was produced in the same manner as in Example 5, except that nOXD and DABAPMB were co-evaporated so as to have a weight percentage ratio of 60:40. This element is light blue (48
1 nm) was obtained, and it was confirmed from the emission spectrum that DABAPMB in the light emitting layer was emitting light. The luminance showed a high value of 8400 cd / m ^{2 at} 12 V. FIG. 6 shows the luminance-voltage characteristics of the obtained organic EL device.

COMPARATIVE EXAMPLE 1 A device as shown in Example 5 was used except that DABAPMB was not co-deposited.
1 × 10 ⁻⁶ Torr with 600 mm thickness only for nOXD
Organic EL was prepared in the same manner as in Example 5 except that
An element was manufactured. In this element, blue light emission was observed at an initial drive of 5 V, and the maximum luminance was 1400 cd at 14 V.
/ M ² , but the initial voltage was higher than that of the element doped with DABAPMB. FIG. 6 shows the luminance-voltage characteristics of the obtained organic EL device.

Example 10 <Preparation of EL Element> (CsBAPMB obtained in Example 2 with 5 wt% doping) FIG. 7 is a sectional view of this example. ITO (indium-tin-) with a sheet resistance of 15Ω / □ on a glass substrate
(Oxide) at 1000 °. Next, TPD as a hole transporting agent is vacuum-deposited at 1.0 × 10 ⁻⁶ Torr to a thickness of 400 °. From there, the following equation

Embedded image And CzBAP obtained in Example 2.
MB was co-evaporated (to a 95: 5 weight percent ratio) to form a 150 ° thick luminescent layer. Further, as an electron transporting layer, ZnOXD was deposited at 450Å, 1 × 10 ⁻⁶ T
Vapor deposition was performed under a vacuum of orr, and finally Mg and Ag (10: 1) were co-deposited at the same degree of vacuum to a thickness of 2000 mm as a cathode electrode. The light emitting region was a square having a length of 0.5 cm and a width of 0.5 cm. In the organic electroluminescent device thus manufactured, ITO was used as an anode, and Mg: Ag was used.
Was used as a cathode, a DC voltage was applied, and light emission was observed through a glass substrate. The brightness was measured by a Topcon brightness meter BM-8. This element is light blue (475 n
m) was obtained, and the Cz of the light emitting layer was determined from the emission spectrum.
It was confirmed that BAPMB emitted light. When the current density-voltage characteristics of this device were measured, it was 300 at 13V.
mA / cm ² . The maximum brightness is 23 at 13V.
00 cd / m ² . FIG. 8 shows luminance-voltage characteristics of the obtained organic EL device, and FIG. 9 shows current density-voltage characteristics.

Example 11 (CzBAPMB 10 wt% doping)
A device was fabricated in the same manner as in Example 10, except that nOXD and CzBAPMB were co-evaporated so as to have a weight percentage ratio of 90:10. This element is light blue (4
Emission of 75 nm was obtained, and it was confirmed from the emission spectrum that CzBAPMB in the emission layer emitted light. When the current density-voltage characteristics of this device were measured, it was 500 mA / cm ² at 14 V. The maximum luminance was 2400 cd / m ² at 13 V. FIG. 8 shows luminance-voltage characteristics of the obtained organic EL device, and FIG. 9 shows current density-voltage characteristics.

Example 12 (When DABAPMB is doped at 20 wt%)
A device was produced in the same manner as in Example 10, except that nOXD and DABAPMB were co-evaporated so as to have a weight percentage ratio of 80:20. This element is light blue (4
Emission of 75 nm was obtained, and it was confirmed from the emission spectrum that CzBAPMB in the emission layer emitted light. When the current density-voltage characteristics of this device were measured, it was 400 mA / cm ² at 13 V. The maximum luminance was 2800 cd / m ² at 13 V. FIG. 8 shows luminance-voltage characteristics of the obtained organic EL device, and FIG. 9 shows current density-voltage characteristics.

Example 13 (When DABAPMB is doped at 30 wt%)
A device was produced in the same manner as in Example 10, except that nOXD and DABAPMB were co-evaporated so that the ratio by weight was 70:30. This element is light blue (4
Emission of 75 nm was obtained, and it was confirmed from the emission spectrum that CzBAPMB in the emission layer emitted light. When the current density-voltage characteristics of this device were measured, it was 600 mA / cm ² at 13 V. The maximum luminance was 3400 cd / m ² at 12 V. FIG. 8 shows luminance-voltage characteristics of the obtained organic EL device, and FIG. 9 shows current density-voltage characteristics.

Comparative Example 2 In the device shown in Example 10, CzBAPMB was not co-deposited, and only ZnOXD was applied to a thickness of 600 ° and 1 × 10 ⁻⁶ Torr.
An organic EL device was produced in the same manner as in Example 10, except that the vacuum evaporation was performed at r. In this element, blue light emission was observed at an initial drive of 5 V, and the maximum luminance was 220 V at 13 V.
Although it was 0 cd / m ² , the initial voltage was higher than that of the device doped with CzBAPMB. When the current density-voltage characteristics were measured, it was found that 6 mA / cm ^{2 at} 9 V and CzB
The value was lower than that of the device doped with APMB. FIG. 8 shows luminance-voltage characteristics of the obtained organic EL device, and FIG. 9 shows current density-voltage characteristics.

[0055]

(1) According to the present invention, a novel heterocyclic ring-containing arylamine compound can be provided. (2) The novel compound of the present invention is useful as a light emitting compound having a hole transporting property and can be used as a light emitting layer of an organic EL device. (3) According to the present invention, an organic EL device having a novel light-emitting layer can be provided.

[Brief description of the drawings]

FIG. 1 is an IR spectrum of DABAPMB obtained in Example 1.

FIG. 2 is a graph of DABAPMB obtained in Example 1.
¹ H-NMR spectrum diagram (solvent: CDCl ₃₎ a.

FIG. 3 is an IR spectrum diagram of CzBAPMB obtained in Example 2.

FIG. 4 shows the CzBAPMB obtained in Example 2.
^{It is a} < ¹ > H-NMR spectrum figure.

FIG. 5 shows a laminated structure of the organic EL elements of Examples 5 to 9.

FIG. 6 shows luminance-voltage characteristics of the organic EL elements of Examples 5 to 9 and Comparative Example 1. A white circle is Example 5, a white triangle is Example 6, a white square is Example 7, a black circle is Example 8, a black triangle is Example 9, and a black square is Comparative Example 1.

FIG. 7 shows a laminated structure of the organic EL elements of Examples 10 to 13 and Comparative Example 2.

FIG. 8 shows luminance-voltage characteristics of the organic EL devices of Examples 10 to 13 and Comparative Example 2. A solid circle is Example 10, a white triangle is Example 11, a white square is Example 12, and a white circle is Example 1.
3. The black square is Comparative Example 2.

FIG. 9 shows current density-voltage characteristics of the organic EL devices of Examples 10 to 13 and Comparative Example 2. A solid circle is Example 10, a white triangle is Example 11, a white square is Example 12, a white circle is Example 13, and a black square is Comparative Example 2.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiyuki Ichiyanagi 2-2-2-5, Murasensenji, Yonezawa-shi, Yamagata Prefecture Corp Haga 205 F-term (reference) 3K007 AB00 AB02 AB03 DA00 DB03 EB00 FA01 4C063 AA01 AA03 BB01 BB09 CC79 DD08 DD31 DD62

Claims (5)

[Claims] [Claim 1] The following general formula (1) (Wherein, Ar ¹ is a heterocyclic group which may have a substituent, may form a condensed ring with a benzene ring to which Ar ¹ is bonded, and R ^{1 to} R ¹⁶ are A group independently selected from the group consisting of a hydrogen atom, an amino group, an alkyl group, an alkoxy group and an aryl group which may have a substituent, and Ar ^{2 to} Ar ⁵ may have a substituent. A heterocyclic-containing arylamine compound having a molecular weight of 750 or more, which is independently selected from the group consisting of aryl groups. 2. In the above general formula (1), Is a skeleton structure serving as an emission center in a light-emitting compound containing a hole-transporting heterocyclic ring, wherein the heterocyclic ring-containing arylamine compound having a molecular weight of 750 or more according to claim 1. 3. The compound of the general formula (1) Is Embedded image (Wherein R ²¹ , R ²² , R ²⁴ and R ²⁶ are hydrogen,
R ²³ is a group independently selected from the group consisting of an alkyl group having 1 to 4 carbon atoms and an alkoxy group having 1 to 4 carbon atoms, and R ²³ is a group consisting of fluorine and a halogenated alkyl group having 1 to 2 carbon atoms. R ²⁵ is a methylene group or an ethylene group. The heterocyclic-containing arylamine compound having a molecular weight of 750 or more according to claim 1, which is a group selected from the group consisting of: 4. The compound of the general formula (1) Is Embedded image The heterocyclic-containing arylamine compound having a molecular weight of 750 or more according to claim 1, which is a group selected from the group consisting of: 5. A molecular weight of 75 according to claim 1,
An organic electroluminescent device comprising a layer containing zero or more heterocyclic-containing arylamine compounds.