AROMATIC AMINE DERIVATIVE AND ORGANIC ELECTROLUMINESCENT DEVICE USING THE SAME

Abstract

Provided are: an aromatic amine derivative in which a terminal substituent such as a dibenzofuran ring or a dibenzothiophene ring is bonded to a nitrogen atom directly or through an arylene group or the like; an organic electroluminescence device including an organic thin film layer formed of one or more layers including a light emitting layer and interposed between a cathode and an anode in which a layer of the organic thin film layer contains the aromatic amine derivative by itself or as a component of a mixture, and the device has a long lifetime and high luminous efficiency; and an aromatic amine derivative for realizing the device.

Claims

1. An aromatic amine derivative represented by the following general formula (1): ##STR00388## wherein: Ar.sub.0 represents a substituted or unsubstituted, divalent fused aromatic hydrocarbon group having 10 to 50 ring-forming carbon atoms, and Ar.sub.1 to Ar.sub.4 each independently represent a substituted or unsubstituted aryl group having 6 to 50 ring-forming carbon atoms, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring-forming carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 50 ring-forming carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring-forming atoms, provided that one, two or three of Ar.sub.1 to Ar.sub.4 each represent a group represented by formula (2): ##STR00389## wherein: n represents an integer of 0 to 3, m represents an integer of 0 to 5, X represents oxygen (O), sulfur (S), or selenium (Se), Ar represents a substituted or unsubstituted arylene group having 6 to 60 ring-forming carbon atoms, R represents a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, an amino group, a substituted or unsubstituted alkoxy group having 1 to 50 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 50 ring-forming carbon atoms, a substituted or unsubstituted arylthio group having 6 to 50 ring-forming atoms, a substituted or unsubstituted alkoxycarbonyl group having 1 to 50 carbon atoms, a halogen atom, a cyano group, a nitro group, a hydroxyl group, a silyl group, or a carboxyl group, when n or m represents 2 or more, multiple Ar's or multiple R's may be identical to or different from each other, and when multiple R's are present, the multiple R's may be bonded to each other to form a saturated or unsaturated, five- or six-membered cyclic structure that may be substituted, provided that: when n=0, a five-membered ring portion including X in the general formula (2) is free from being directly bonded to N bonded to Ar.sub.0.

2. The aromatic amine derivative according to claim 1, wherein Ar.sub.0 in the general formula (1) represents a substituted or unsubstituted naphthylene group, a substituted or unsubstituted anthracenylene group, a substituted or unsubstituted phenanthrylene group, a substituted or unsubstituted chrysenylene group, a substituted or unsubstituted pyrenylene group, or a substituted or unsubstituted benzoanthracenylene group.

3. The aromatic amine derivative according to claim 2, wherein: —NAr.sub.1Ar.sub.2 and —NAr.sub.3Ar.sub.4 are bonded to 2- and 6-positions of the naphthylene group, respectively, —NAr.sub.1Ar.sub.2 and —NAr.sub.3Ar.sub.4 are bonded to 9- and 10-positions of the anthracenylene group, respectively, —NAr.sub.1Ar.sub.2 and —NAr.sub.3Ar.sub.4 are bonded to 2- and 6-positions of the anthracenylene group, respectively, —NAr.sub.1Ar.sub.2 and —NAr.sub.3Ar.sub.4 are bonded to 2- and 7-positions of the phenanthrylene group, respectively, —NAr.sub.1Ar.sub.2 and —NAr.sub.3Ar.sub.4 are bonded to 6- and 12-positions of the chrysenylene group, respectively, —NAr.sub.1Ar.sub.2 and —NAr.sub.3Ar.sub.4 are bonded to 1- and 6-positions of the pyrenylene group, respectively, —NAr.sub.1Ar.sub.2 and —NAr.sub.3Ar.sub.4 are bonded to 2- and 7-positions of the pyrenylene group, respectively, or —NAr.sub.1Ar.sub.2 and —NAr.sub.3Ar.sub.4 are bonded to 7- and 12-positions of the benzoanthracenylene group, respectively.

4. The aromatic amine derivative according to claim 1, wherein Ar.sub.1 and Ar.sub.3 each represent a group represented by the general formula (2).

5-6. (canceled)

7. The aromatic amine derivative according to claim 1, wherein n in formula (2) represents 0.

8. The aromatic amine derivative according to claim 1, wherein m in formula (2) represents 0.

9. The aromatic amine derivative according to claim 1, wherein x in formula (2) represents an oxygen atom.

10. (canceled)

11. The aromatic amine derivative according to claim 1, wherein X in formula (2) represents a sulfur atom.

12. (canceled)

13. The aromatic amine derivative according to claim 1, wherein R in formula (2) represents a silyl group.

14. The aromatic amine derivative according to claim 1, wherein the aromatic amine derivative is a light emitting material for an organic electroluminescence device.

15. The aromatic amine derivative according to claim 1, wherein the aromatic amine derivative is a blue light emitting material for an organic electroluminescence device.

16. The aromatic amine derivative according to claim 1, wherein the aromatic amine derivative is a green light emitting material for an organic electroluminescence device.

17. The aromatic amine derivative according to claim 1, wherein the aromatic amine derivative is a doping material for an organic electroluminescence device.

18-22. (canceled)

Description

EXAMPLES

[0129] Next, the present invention is described in more detail by way of examples.

Synthesis Example 1 (Synthesis of Compound D1)

(1) Synthesis of N-(2-dibenzofuranyl)acetamide

[0130] In a stream of argon, 4.25 g of acetamide, 17.8 g of 2-bromodibenzofuran, 0.7 g of copper iodide, 0.63 g of N,N′-dimethylethylenediamine, 39.7 g of potassium carbonate, and xylene were subjected to a reaction under reflux for 12 hours.

[0131] After having been cooled, the resultant was filtrated, and then clean water and toluene were added to the filtrate so that an organic layer might be separated. The organic layer was washed with clean water three times, and was then concentrated under reduced pressure . As a result, 14.4 g of a yellowish white solid were obtained. The solid was identified as N-(2-dibenzofuranyl)acetamide by field desorption mass spectrometry (FD-MS).

(2) Synthesis of N-(2-dibenzofuranyl)-N-phenylacetamide

[0132] Synthesis was performed in the same manner as in the synthesis of N-(2-dibenzofuranyl)acetamide in the section (1) except that N-(2-dibenzofuranyl)acetamide was used instead of acetamide, and bromobenzene was used instead of 2-bromodibenzofuran. The resultant was identified as N-(2-dibenzofuranyl)-N-phenylacetamide by field desorption mass spectrometry (FD-MS).

(3) Synthesis of N-(2-dibenzofuranyl)-N-phenylamine

[0133] First, 7.9 g of N-(2-dibenzofuranyl)-N-phenylacetamide, 8.8 g of potassium hydroxide, 10 mL of clean water, 25 mL of ethanol, and 50 mL of toluene were loaded, and then the mixture was subjected to a reaction under reflux for 7 hours.

[0134] After the resultant had been cooled, clean water was added to the resultant, and then the mixture was filtrated. Clean water and toluene were added to the filtrate so that an organic layer might be separated. The organic layer was washed with clean water three times, and was then concentrated. The resultant coarse product was recrystallized with toluene and ethanol, and then the resultant solid was dried under reduced pressure. As a result, 4.2 g of a white solid were obtained. The solid was identified as N-(2-dibenzofuranyl)-N-phenylamine by FD-MS.

(4) Synthesis of Compound D1

[0135] In a stream of argon, 4.2 g of N-(2-dibenzofuranyl)-N-phenylamine, 2.8 g of 6,12-dibromochrysene, 186 mg of Pd.sub.2(dba).sub.3, 259 mg of P(t-Bu).sub.3, 4.3 g of t-butoxysodium, and 20 mL of toluene were loaded, and then the mixture was subjected to a reaction at 80° C. for 4 hours.

[0136] After the resultant had been cooled, toluene was added to the resultant, and then the mixture was subjected to celite filtration. After that, the filtrate was concentrated, and then the resultant concentrate was purified by silica gel chromatography (hexane:dichloromethane=6:1). The resultant solid was washed with n-hexane, and was then dried under reduced pressure. As a result, 3.2 g of a yellowish white solid were obtained. The solid was identified as Compound D1 by FD-MS.

[0137] Synthesis Example 2 (synthesis of Compound D21)

[0138] Synthesis was performed in the same manner as in the foregoing except that 9,10-dibromoanthracene was used instead of 6,12-dibromochrysene in the section (4) of Synthesis Example 1. The resultant was identified as Compound D21 by FD-MS.

[0139] Synthesis Example 3 (synthesis of Compound D57)

(1) Synthesis of N,N-(di-2-dibenzofuranyl)acetamide

[0140] In a stream of argon, 4.25 g of acetamide, 37.0 g of 2-bromodibenzofuran, 0.7 g of copper iodide, 0.63 g of N,N′-dimethylethylenediamine, 39.7 g of potassium carbonate, and xylene were subjected to a reaction under reflux for 12 hours.

[0141] After having been cooled, the resultant was filtrated, and then clean water and toluene were added to the filtrate so that an organic layer might be separated. The organic layer was washed with clean water three times, and was then concentrated under reduced pressure. As a result, 22.5 g of a white solid were obtained. The solid was identified as N,N-(di-2-dibenzofuranyl)acetamide by FD-MS.

(2) Synthesis of N,N-(di-2-dibenzofuranyl)amine

[0142] Synthesis was performed in the same manner as in the section (3) of Synthesis Example 1 except that N,N-(di-2-dibenzofuranyl) acetamide synthesized in the section (1) was used instead of N-(2-dibenzofuranyl)-N-phenylacetamide in the synthesis of N-(2-dibenzofuranyl)-N-phenylamine. The resultant was identified as N,N-(di-2-dibenzofuranyl)amine by FD-MS.

(3) Synthesis of Compound D57

[0143] Synthesis was performed in the same manner as in the section (4) of Synthesis Example 1 except that 1,5-di-t-butyl-3,7-dibromonaphthalene was used instead of 6,12-dibromochrysene, and N,N-(di-2-dibenzofuranyl)amine was used instead of N-(2-dibenzofuranyl)-N-phenylamine. The resultant was identified as Compound D57 by FD-MS.

Example 1

[0144] A transparent electrode formed of indium tin oxide and having a thickness of 120 nm was provided on a glass substrate measuring 25 mm by 75 mm by 1.1 mm. The glass substrate was subjected to UV/ozone irradiation, and washed. After that, the substrate was placed in a vacuum deposition apparatus.

[0145] First, N′,N″-bis[4-(diphenylamino)phenyl]-N′,N″-diphenylbiphenyl-4,4′-diamine was deposited from the vapor so as to serve as a hole injecting layer having a thickness of 60 nm. After that, N,N,N′,N′-tetrakis(4-biphenyl)-4,4′-benzidine was deposited from the vapor onto the layer so as to serve as a hole transporting layer having a thickness of 20 nm. Next, 10,10′-bis[1,1′,4′,1″]terphenyl-2-yl-9,9′-bianthracenyl (BTBAN) as a host material and Compound D1 described above as a doping material were simultaneously deposited from the vapor at a weight ratio of 40:2 so that a light emitting layer having a thickness of 40 nm might be formed.

[0146] Next, tris(8-hydroxyquinolinato) aluminum was deposited from the vapor onto the light emitting layer so as to serve as an electron injecting layer having a thickness of 20 nm. Then, lithium fluoride was deposited from the vapor so as to have a thickness of 1 nm, and then aluminum was deposited from the vapor so as to have a thickness of 150 nm. The aluminum/lithium fluoride functions as a cathode. Thus, an organic EL device was produced.

[0147] The resultant device was then subjected to an energization test. As a result, blue light emission having a current efficiency of 6.1 cd/A and an emission luminance of 600 cd/m.sup.2 (luminous maximum wavelength: 458 nm) was obtained at a voltage of 6.4 V and a current density of 10 mA/cm.sup.2. A continuous DC energization test was performed at an initial luminance of 500 cd/m.sup.2. As a result, a half lifetime was 10,000 hours.

Example 2

[0148] An organic EL device was produced in the same manner as in Example 1 except that Compound D50 was used instead of Compound D1 as a doping material.

[0149] The resultant device was subjected to an energization test. As a result, green light emission having a current efficiency of 18.1 cd/A and an emission luminance of 1800 cd/m.sup.2 (luminous maximum wavelength: 520 nm) was obtained at a voltage of 6.0 V and a current density of 10 mA/cm.sup.2. A continuous DC energization test was performed at an initial luminance of 500 cd/m.sup.2. As a result, a half lifetime was 35,000 hours.

Example 3

[0150] An organic EL device was produced in the same manner as in

[0151] Example 1 except that Compound D22 was used instead of Compound D1 as a doping material.

[0152] The resultant device was subjected to an energization test. As a result, blue light emission having a current efficiency of 7.5 cd/A and an emission luminance of 750 cd/m.sup.2 (luminous maximum wavelength: 466 nm) was obtained at a voltage of 6.2 V and a current density of 10 mA/cm.sup.2. A continuous DC energization test was performed at an initial luminance of 500 cd/m.sup.2. As a result, a half lifetime was 14,000 hours.

Comparative Example 1

[0153] An organic EL device was produced in the same manner as in Example 1 except that 6,12-bis(diphenylamino)chrysene was used instead of Compound D1 as a doping material.

[0154] The resultant device was subjected to an energization test. As a result, blue light emission having a current efficiency of 3.5 cd/A and an emission luminance of 311 cd/m.sup.2 (luminous maximum wavelength: 451 nm) was obtained at a voltage of 6.2 V and a current density of 10 mA/cm.sup.2. A continuous DC energization test was performed at an initial luminance of 500 cd/m.sup.2. As a result, a half lifetime was as short as 1000 hours.

INDUSTRIAL APPLICABILITY

[0155] As specifically described above, the organic EL device using the aromatic amine derivative of the present invention has high luminous efficiency, hardly deteriorates even after long-term use, and has a long lifetime. Therefore, the organic EL device is useful as a flat luminous body of a wall hanging television or a light source for backlight or the like of a display.