ORGANIC ELECTROLUMINESCENT COMPOUND AND ORGANIC ELECTROLUMINESCENT DEVICE COMPRISING THE SAME

Abstract

The present disclosure relates to an organic electroluminescent compound, and an organic electroluminescent device comprising the same. By comprising the organic electroluminescent compound of the present disclosure, it is possible to provide an organic electroluminescent device having improved driving voltage, lifetime properties, and/or power efficiency.

Claims

1. An organic electroluminescent compound represented by the following formula 1: ##STR00046## wherein L.sub.1 and L.sub.2 each independently represent a single bond, a substituted or unsubstituted (C6-C30)arylene, or a substituted or unsubstituted (5- to 30-membered)heteroarylene; Ar.sub.1 represents a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (5- to 30-membered)heteroaryl; Ar.sub.2 represents the following formula 1-1 or 1-2; ##STR00047## R.sub.1 and R.sub.2 each independently represent hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (5- to 30-membered)heteroaryl; R.sub.3 to R.sub.9 each independently represent hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (5- to 30-membered)heteroaryl, or may be linked to L.sub.2; X represents O, S, or N—R.sub.11; R.sub.11 represents a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (5- to 30-membered)heteroaryl, or may be linked to L.sub.2; and a, b, d, h, and i each independently represent an integer of 1 to 4, c represents an integer of 1 to 5, e and f each independently represent an integer of 1 to 3, and g represents an integer of 1 to 2, where if a to i are an integer of 2 or more, each of R.sub.1 to each of R.sub.9 may be the same or different.

2. The organic electroluminescent compound according to claim 1, wherein formula 1 is represented by any one of the following formulas 2-1 to 2-9: ##STR00048## ##STR00049## ##STR00050## wherein Ar.sub.1, R.sub.1 to R.sub.9, L.sub.1, L.sub.2, X, and a to i are as defined in claim 1.

3. The organic electroluminescent compound according to claim 1, wherein the substituents of the substituted alkyl, the substituted aryl, the substituted arylene, the substituted heteroaryl, and the substituted heteroarylene in L.sub.1, L.sub.2, R.sub.1 to R.sub.9, R.sub.11, and Ar.sub.1 each independently are at least one selected from the group consisting of deuterium; a halogen; a cyano; a carboxyl; a nitro; a hydroxyl; a (C1-C30)alkyl; a halo(C1-C30)alkyl; a (C2-C30)alkenyl; a (C2-C30)alkynyl; a (C1-C30)alkoxy; a (C1-C30)alkylthio; a (C3-C30)cycloalkyl; a (C3-C30)cycloalkenyl; a (3- to 7-membered)heterocycloalkyl; a (C6-C30)aryloxy; a (C6-C30)arylthio; a (3- to 30-membered)heteroaryl unsubstituted or substituted with a (C6-C30)aryl(s); a (C6-C30)aryl unsubstituted or substituted with at least one of a (C1-C30)alkyl(s) and a (3- to 30-membered)heteroaryl(s); a tri(C1-C30)alkylsilyl; a tri(C6-C30)arylsilyl; a di(C1-C30)alkyl(C6-C30)arylsilyl; a (C1-C30)alkyldi(C6-C30)arylsilyl; an amino; a mono- or di-(C1-C30)alkylamino; a mono- or di-(C2-C30)alkenylamino; a mono- or di-(C6-C30)arylamino; a mono- or di-(3- to 30-membered)heteroarylamino; a (C1-C30)alkyl(C2-C30)alkenylamino; a (C1-C30)alkyl(C6-C30)arylamino; a (C1-C30)alkyl(3- to 30-membered)heteroarylamino; a (C2-C30)alkenyl(C6-C30)arylamino; a (C2-C30)alkenyl(3-to 30-membered)heteroarylamino; a (C6-C30)aryl(3- to 30-membered)heteroarylamino; a (C1-C30)alkylcarbonyl; a (C1-C30)alkoxycarbonyl; a (C6-C30)arylcarbonyl; a di(C6-C30)arylboronyl; a di(C1-C30)alkylboronyl; a (C1-C30)alkyl(C6-C30)arylboronyl; a (C6-C30)aryl(C1-C30)alkyl; and a (C1-C30)alkyl(C6-C30)aryl.

4. The organic electroluminescent compound according to claim 1, wherein the compound represented by formula 1 is selected from the following compounds: ##STR00051## ##STR00052## ##STR00053## ##STR00054##

5. An organic electroluminescent device comprising a first electrode; a second electrode; and a plurality of organic layers comprising a light-emitting layer between the first electrode and the second electrode, wherein at least two layers of the organic layers comprise one or more of compounds represented by the following formulas 3-1 and 3-2: ##STR00055## wherein R.sub.3′ to R.sub.9′ each independently represent hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C60)aryl, a substituted or unsubstituted (3- to 60-membered)heteroaryl, a substituted or unsubstituted (C3-C30)cycloalkyl, a fused ring group of a substituted or unsubstituted (C3-C30) aliphatic ring(s) and a substituted or unsubstituted (C6-C30) aromatic ring(s), a substituted or unsubstituted (C2-C30)alkenyl, a substituted or unsubstituted (C2-C30)alkynyl, a substituted or unsubstituted (C1-C30)alkoxy, a substituted or unsubstituted (C6-C30)aryloxy, a substituted or unsubstituted mono- or di-(C1-C30)alkylamino, a substituted or unsubstituted mono- or di-(C2-C30)alkenylamino, a substituted or unsubstituted mono- or di-(C6-C30)arylamino, a substituted or unsubstituted mono- or di-(3- to 30-membered)heteroarylamino, a substituted or unsubstituted (C1-C30)alkyl(C2-C30)alkenylamino, a substituted or unsubstituted (C1-C30)alkyl(C6-C30)arylamino, a substituted or unsubstituted (C1-C30)alkyl(3- to 30-membered)heteroarylamino, a substituted or unsubstituted (C2-C30)alkenyl(C6-C30)arylamino, a substituted or unsubstituted (C2-C30)alkenyl(3- to 30-membered)heteroarylamino, or a substituted or unsubstituted (C6-C30)aryl(3- to 30-membered)heteroarylamino, or may be linked to an adjacent substituent to form a ring(s); X′ represents O, S, or N—R.sub.11′; R.sub.11′ represents -L.sub.11-Ar.sub.3; L.sub.11 represents a single bond, a substituted or unsubstituted (C6-C30)arylene, or a substituted or unsubstituted (5- to 30-membered)heteroarylene; Ar.sub.3 represents hydrogen, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (5- to 30-membered)heteroaryl, a substituted or unsubstituted mono- or di-(C6-C60)arylamino, a substituted or unsubstituted mono- or di-(3- to 60-membered)heteroarylamino, or a substituted or unsubstituted (C6-C60)aryl(3- to 60-membered)heteroarylamino; and c′ represents an integer of 1 to 5, d′, h′, and i′ each independently represent an integer of 1 to 4, e′ and f′ each independently represent an integer of 1 to 3, and g′ represents an integer of 1 to 2, where if c′ to i′ are an integer of 2 or more, each of R.sub.3′ to each of R.sub.9′ may be the same or different.

6. The organic electroluminescent device according to claim 5, wherein the compound represented by formula 3-1 or 3-2 is comprised in at least the light-emitting layer.

7. The organic electroluminescent device according to claim 5, wherein the compound represented by formula 3-1 or 3-2 is comprised in at least one layer of the organic layers between the first electrode and the light-emitting layer.

8. The organic electroluminescent device according to claim 5, wherein the compound represented by formula 3-1 or 3-2 comprised in at least one organic layer is represented by formula 1, and the compound represented by formula 3-1 or 3-2 comprised in at least another organic layer is represented by formula 4: ##STR00056## wherein L.sub.1 and L.sub.2 each independently represent a single bond, a substituted or unsubstituted (C6-C30)arylene, or a substituted or unsubstituted (5- to 30-membered)heteroarylene; Ar.sub.1 represents a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (5- to 30-membered)heteroaryl; Ar.sub.2 represents the following formula 1-1 or 1-2; ##STR00057## wherein at least one of Ar.sub.21 to Ar.sub.23 each independently represent the following formula 1-1 or 1-2, and the other(s) of Ar.sub.2 to Ar.sub.23 each independently represent a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (5- to 30-membered)heteroaryl; L.sub.21 to L.sub.23 each independently represent a single bond, a substituted or unsubstituted (C6-C30)arylene, or a substituted or unsubstituted (5- to 30-membered)heteroarylene; ##STR00058## R.sub.1 and R.sub.2 each independently represent hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (5- to 30-membered)heteroaryl; R.sub.3 to R.sub.9 each independently represent hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (5- to 30-membered)heteroaryl, or may be linked to L.sub.2, or also may be linked to one or more of L.sub.21 to L.sub.23; X represents O, S, or N—R.sub.11; R.sub.11 represents a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (5- to 30-membered)heteroaryl, or may be linked to L.sub.2, or also may be linked to one or more of L.sub.21 to L.sub.23; and a, b, d, h, and i each independently represent an integer of 1 to 4, c represents an integer of 1 to 5, e and f each independently represent an integer of 1 to 3, and g represents an integer of 1 to 2, where if a to i are an integer of 2 or more, each of R.sub.1 to each of R.sub.9 may be the same or different.

9. The organic electroluminescent device according to claim 8, wherein the compound represented by formula 4 is selected from the following compounds: ##STR00059## ##STR00060## ##STR00061## ##STR00062## ##STR00063## ##STR00064## ##STR00065## ##STR00066## ##STR00067##

10. The organic electroluminescent device according to claim 8, wherein the compound represented by formula 1 is selected from the following compounds: ##STR00068## ##STR00069## ##STR00070## ##STR00071##

Description

EXAMPLE 1: PREPARATION OF COMPOUND 1-3

[0096] ##STR00032## ##STR00033##

Synthesis of Compound 1-3-2

[0097] Compound 1-3-3 (10 g, 34.3 mmol), 1-bromo-4-iodobenzene (24.3 g, 85.8 mmol), copper(I) iodide (3.27 g, 17.2 mmol), ethylenediamine (2.06 g, 34.3 mmol), and potassium phosphate (21.9 g, 103 mmol) were introduced into toluene (170 mL) in a flask and dissolved, and the mixture was refluxed for 2 hours. After completion of the reaction, the reaction mixture was cooled to room temperature and distilled water was added thereto. After extracting with ethyl acetate, the residue was dried with magnesium sulfate. The residue was distilled under reduced pressure and separated by column chromatography to obtain compound 1-3-2 (13.2 g, yield: 86.2%).

Synthesis of Compound 1-3-1

[0098] Compound 1-3-2 (13.2 g, 29.6 mmol), bis(pinacolato)diboron (9.76 g, 38.4 mmol), bis (triphenylphosphine)palladium(I)dichloride (830 mg, 1.18 mmol), and potassium acetate (12.8 g, 130 mmol) were introduced into 1,4-dioxane (295 mL) in a flask and dissolved, and the mixture was refluxed at 120° C. for 24 hours. After completion of the reaction, an organic layer was separated with ethyl acetate, and the residual moisture was removed with magnesium sulfate. The residue was separated by column chromatography to obtain compound 1-3-1 (9.4 g, yield: 64.4%).

Synthesis of Compound 1-3

[0099] Compound 1-3-1 (9.4 g, 19.1 mmol), compound A (6.35 g, 19.1 mmol), tetrakis(triphenylphosphine)palladium(0) (1.1 g, 0.953 mmol), and potassium carbonate (7.9 g, 57.2 mmol) were introduced into toluene (78 mL), ethanol (23.5 mL), and water (23.5 mL) in a flask and dissolved, and the mixture was refluxed at 120° C. for 24 hours. After completion of the reaction, an organic layer was separated with ethyl acetate, and the residual moisture was removed with magnesium sulfate. The residue was separated by column chromatography to obtain compound 1-3 (2.7 g, 4.36 mmol).

TABLE-US-00001 Compound MW Tg M.P. 1-3 619.77 169.72° C. 319.6° C.

EXAMPLE 2: PREPARATION OF COMPOUND 2-2

[0100] ##STR00034##

Synthesis of Compound 2-2-1

[0101] Compound 1-3-3 (15.0 g, 51.5 mmol), 1-bromo-3-iodobenzene (29.3 g, 103 mmol), copper(I) iodide (4.9 g, 25.8 mmol), ethylenediamine (7.0 mL, 103 mmol), and potassium phosphate (27.5 g, 129 mmol) were introduced into toluene (250 mL) in a flask and dissolved, and the mixture was stirred under reflux for 4 hours. After completion of the reaction, the reaction mixture was cooled to room temperature and filtered with a silica gel. The organic layer was condensed and recrystallized with ethyl acetate to obtain compound 2-2-1 (14.2 g, yield: 62%).

Synthesis of Compound 2-2

[0102] Compound 2-2-1 (5.0 g, 11.2 mmol), N-phenyl-[1,1′-biphenyl]-4-amine (3.0 g, 12.3 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.5 g, 0.56 mmol), s-phos (0.46 g, 1.12 mmol), and sodium tert-butoxide (2.7 g, 28 mmol) were introduced into toluene (60 mL) in a flask and dissolved, and the mixture was stirred under reflux for 6 hours. After completion of the reaction, the reaction mixture was cooled to room temperature, stirred at room temperature, and methanol was added thereto. The obtained solid was filtered under reduced pressure, and separated by column chromatography to obtain compound 2-2 (2.3 g, yield: 34%).

TABLE-US-00002 Compound MW Tg M.P. 2-2 610.8 112.31° C. 132° C.

EXAMPLE 3: PREPARATION OF COMPOUND 2-3

[0103] ##STR00035##

[0104] Compound 2-2-1 (14.0 g, 31.4 mmol), N-phenyl-[1,1-biphenyl]-3-amine (7.78 g, 31.7 mmol), tris(dibenzylideneacetone)dipalladium(0) (1.44 g, 1.57 mmol), tri-tert-butylphosphine (635 mg, 3.14 mmol), and sodium tert-butoxide (6.04 g, 62.8 mmol) were introduced into toluene (160 mL) in a flask and dissolved, and the mixture was stirred under reflux for 2 hours. After completion of the reaction, the reaction mixture was cooled to room temperature, and extracted with distilled water and ethyl acetate. The organic layer was distilled under reduced pressure, and separated by column chromatography to obtain compound 2-3 (14.6 g, yield: 76%).

TABLE-US-00003 Compound MW Tg M.P. 2-3 610.7 103.6° C. 141° C.

DEVICE EXAMPLE 1: PRODUCING AN OLED DEPOSITED WITH THE ORGANIC ELECTROLUMINESCENT COMPOUND ACCORDING TO THE PRESENT DISCLOSURE

[0105] An OLED according to the present disclosure was produced. A transparent electrode indium tin oxide (ITO) thin film (10 Ω/sq) on a glass substrate for an OLED (GEOMATEC CO., LTD., Japan) was subjected to an ultrasonic washing with acetone, ethanol, and distilled water, sequentially, and then was stored in isopropyl alcohol. The ITO substrate was then mounted on a substrate holder of a vacuum vapor deposition apparatus. Compound HT was introduced into a cell of the vacuum vapor deposition apparatus, and compound HI was introduced into another cell of the vacuum vapor deposition apparatus. The two materials were evaporated at different rates, and compound HI was deposited in a doping amount of 3 wt % based on the total amount of compound HT and compound HI to form a hole injection layer having a thickness of 10 nm on the ITO substrate. Next, compound HT was deposited on the hole injection layer to form a first hole transport layer having a thickness of 75 nm. Compound HT was deposited on the first hole transport layer to form a second hole transport layer having a thickness of 5 nm. After forming the hole injection layer and the hole transport layers, a light-emitting layer was formed thereon as follows: Compound 1-3 was introduced into one cell of the vacuum vapor depositing apparatus as a host of the light-emitting layer, and compound BD was introduced into another cell. The two materials were evaporated at different rates, and respectively deposited in a doping amount of 2 wt % based on the total amount of the host and dopant to form a light-emitting layer having a thickness of 20 nm on the second hole transport layer. Subsequently, compound ET-1 was deposited as a hole blocking layer in a thickness of 5 nm. Next, in two other cells compound ET-2 and compound EI-1 were evaporated at a rate of 1:1 (weight ratio) to deposit an electron transport layer having a thickness of 30 nm on the hole blocking layer. After depositing compound EI-1 as an electron injection layer having a thickness of 2 nm, an Al cathode having a thickness of 80 nm was deposited by another vacuum vapor deposition apparatus to produce an OLED.

[0106] As a result, the driving voltage obtained at a luminance of 1,000 nit was 3.2 V, the power efficiency was 5.9 lm/W, and the minimum time taken for luminance to decrease from 100% to 95% was 31.1 hours.

COMPARATIVE EXAMPLE: PRODUCING AN OLED COMPRISING A CONVENTIONAL COMPOUND

[0107] An OLED was produced in the same manner as in Device Example 1, except that compound BH-2 was used as the host of the light-emitting layer.

[0108] As a result, the driving voltage obtained at a luminance of 1,000 nit was 4.1 V, the power efficiency was 5.9 lm/N, and the minimum time taken for luminance to decrease from 100% to 95% was 14.6 hours.

[0109] As can be seen from the result above, it is verified that the OLED comprising the organic electroluminescent compound according to the present disclosure as a host material can significantly lower the driving voltage and have remarkably improved lifetime properties compared to the OLED using a conventional compound.

DEVICE EXAMPLE 2: PRODUCING AN OLED DEPOSITED WITH THE ORGANIC ELECTROLUMINESCENT COMPOUND ACCORDING TO THE PRESENT DISCLOSURE

[0110] An OLED was produced in the same manner as in Device Example 1, except that compound 2-2 was used instead of compound HT as the second hole transport material.

[0111] As a result, the driving voltage obtained at a luminance of 1,000 nit was 3.2 V, and the power efficiency was 6.9 lm/W.

DEVICE EXAMPLE 3: PRODUCING AN OLED DEPOSITED WITH THE ORGANIC ELECTROLUMINESCENT COMPOUND ACCORDING TO THE PRESENT DISCLOSURE

[0112] An OLED was produced in the same manner as in Device Example 1, except that compound 2-3 was used instead of compound HT as the second hole transport material.

[0113] As a result, the driving voltage obtained at a luminance of 1,000 nit was 3.2 V, and the power efficiency was 6.9 lm/W.

[0114] As can be seen from the result above, it is verified that the OLEDs comprising the organic electroluminescent compound according to the present disclosure as a second hole transport material and a host material can significantly lower the driving voltage and have remarkably improved power efficiency properties compared to the OLED using a conventional compound. High power efficiency in display implementation can represent a higher performance display by implementing an organic electroluminescent device with lower power consumption.

TABLE-US-00004 TABLE 3 Organic Electroluminescent Material Used in the Device Examples and the Comparative Example Hole Injection Layer/ Hole Transport Layer [00036] [00037] [00038] [00039] Light-Emitting Layer [00040] [00041] [00042] Electron Transport Layer/ Electron Injection Layer [00043] [00044] [00045]