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 including the same. The organic electroluminescent compound of the present disclosure can be included in a light-emitting layer and is effective for producing an organic electroluminescent device having high luminous efficiency and / or excellent lifetime characteristics.

Description

Technical Field

[0001] The present disclosure relates to an organic electroluminescent compound and an organic electroluminescent device including the same. Background Art

[0002] An electroluminescent (EL) device is a self-luminous device, and it has advantages in that it provides a wider viewing angle, a greater contrast ratio, and a faster response time. The organic EL device was first developed by Eastman Kodak in 1987 by using small aromatic diamine molecules and an aluminum complex as materials for forming a light-emitting layer [Appl. Phys. Lett. 51, 913, 1987].

[0003] An organic electroluminescent device (OLED) converts electrical energy into light by applying an electric power to an organic light-emitting material, and generally includes an anode, a cathode, and an organic layer formed between the two electrodes. The organic layer of the OLED may include a hole injection layer, a hole transport layer, a hole assisting layer, a light-emitting assisting layer, an electron blocking layer, a light-emitting layer (including a host and a dopant material), an electron buffer layer, a hole blocking layer, an electron transport layer, an electron injection layer, etc. The materials used in the organic layer can be classified into hole injection materials, hole transport materials, hole assisting materials, light-emitting assisting materials, electron blocking materials, light-emitting materials, electron buffer materials, hole blocking materials, electron transport materials, electron injection materials, etc. In the OLED, due to the applied voltage, holes are injected from the anode into the light-emitting layer, electrons are injected from the cathode into the light-emitting layer, and high-energy excitons are formed by the recombination of holes and electrons. Through this energy, the organic light-emitting compound reaches an excited state, and light emission occurs by emitting light from the energy recovered from the organic light-emitting compound in the excited state to the ground state.

[0004] Recently, according to the larger area of the display, there is a need for light-emitting materials that can exhibit more delicate and vivid colors. Specifically, in the case of materials that emit blue light, materials such as ADN and DPVBi are used as host materials, and materials such as aromatic amine-based compounds, copper phthalocyanine compounds, carbazole-based derivatives, perylene-based derivatives, coumarin-based derivatives, and pyrene-based derivatives are used as dopant materials. However, it is difficult to obtain a dark blue color with high color purity with these materials, and there is a problem in that the emission lifetime is shorter as the wavelength becomes shorter.

[0005] Therefore, in realizing a full-color display, there is a need to develop a light-emitting material having a long lifetime and a dark blue color and other organic materials having energy levels matching those of the material that emits blue light.

[0006] U.S. Patent No. 8,759,818 and U.S. Patent Application Publication No. 2014 / 0001459 disclose organic electroluminescent compounds containing an anthracene moiety, some of the hydrogen atoms of which are replaced by deuterium. However, these references do not specifically disclose an organic electroluminescent compound containing an anthracene moiety, some of the hydrogen atoms of which are replaced by deuterium, and in which dibenzofuran is substituted at a certain position. SUMMARY OF THE INVENTION

[0007] TECHNICAL PROBLEM

[0008] The object of the present disclosure is firstly to provide an organic electroluminescent compound which is effective for producing an organic electroluminescent device having excellent lifetime characteristics; and secondly to provide an organic electroluminescent device containing the organic electroluminescent compound.

[0009] SOLUTION TO THE PROBLEM

[0010] In an organic electroluminescent device, it is important to improve the blue light-emitting material or the blue light-emitting device. However, since the time of developing organic electroluminescent devices, there has been no change in using compounds having a main moiety of anthracene as a blue host material. Therefore, there are limitations in improving the lifetime characteristics of the blue light-emitting material or the blue light-emitting device. In order to improve the lifetime characteristics, the stability of the anthracene compound contained in the blue host material can be increased. One method is deuteration. When deuterating an anthracene compound, the zero-point vibrational energy of the compound can be reduced, thereby increasing the bond dissociation energy (BDE) of the compound. Therefore, the stability of the anthracene compound can be increased. Figure 1 is a graph showing the increase in bond dissociation energy due to deuteration. Specifically, the inventors of the present invention found that when deuterating an organic electroluminescent compound having a specific structure of Formula 1, a more significant improvement in lifetime is produced compared to anthracene compounds having other structures. By bonding a heteroaryl group rather than an aryl group to the anthracene nucleus, the mobility of holes and / or electrons can be improved, thereby reducing the driving voltage.

[0011]

[0012] Wherein

[0013] R1 to R8 each independently represent hydrogen, deuterium, halogen, cyano, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl, or substituted or unsubstituted (5-membered to 30-membered) heteroaryl, provided that one of R2 to R4 is bonded to

[0014] R9 to R 16 each independently represent hydrogen or deuterium;

[0015] Ar1 represents a substituted or unsubstituted (C6-C30) aryl group, or a substituted or unsubstituted (5-membered to 30-membered) heteroaryl group;

[0016] D N means that N hydrogen atoms are replaced by deuterium; and

[0017] N represents an integer from 8 to 50.

[0018] Advantages of the present invention

[0019] By using the organic electroluminescent compound according to the present disclosure, an organic electroluminescent device having an improved blue light emission lifetime can be produced. Description of the drawings

[0020] Figure 1 is a diagram showing an increase in bond dissociation energy due to deuteration. Detailed description

[0021] Hereinafter, the present disclosure will be described in detail. However, the following description is intended to explain the present invention and does not mean to limit the scope of the present invention in any way.

[0022] The term "organic electroluminescent compound" in the present disclosure means a compound that can be used in an organic electroluminescent device and can be included in any layer constituting the organic electroluminescent device if necessary.

[0023] The term "organic electroluminescent material" in the present disclosure means a material that can be used in an organic electroluminescent device and can include at least one compound. If necessary, the organic electroluminescent material can be included in any layer constituting the organic electroluminescent device. For example, the organic electroluminescent material can be a hole injection material, a hole transport material, a hole assisting material, a light emission assisting material, an electron blocking material, a light emitting material, an electron buffering material, a hole blocking material, an electron transport material, an electron injection material, etc.

[0024] The organic electroluminescent material of the present disclosure can include at least one compound represented by Formula 1. The compound represented by Formula 1 can be included in the light emitting layer or the hole transport layer, but is not limited thereto. For example, when included in the light emitting layer, the compound represented by Formula 1 can be included as a host, such as a host for emitting blue light. According to an embodiment of the present disclosure, the compound having Formula 1 can be a fluorescent host, for example, a fluorescent host for emitting blue light.

[0025] Hereinafter, the compound represented by Formula 1 will be described in more detail.

[0026] As used herein, the term “(C1-C30)alkyl” means a straight-chain or branched-chain alkyl group having 1 to 30 carbon atoms forming the chain, wherein the number of carbon atoms is preferably 1 to 20, and more preferably 1 to 10. The above alkyl groups may include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, etc. The term “(C2-C30)alkenyl” means a straight-chain or branched-chain alkenyl group having 2 to 30 carbon atoms forming the chain, wherein the number of carbon atoms is preferably 2 to 20, and more preferably 2 to 10. The above alkenyl groups may include vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-methylbut-2-enyl, etc. The term “(C2-C30)alkynyl” means a straight-chain or branched-chain alkynyl group having 2 to 30 carbon atoms forming the chain, wherein the number of carbon atoms is preferably 2 to 20, and more preferably 2 to 10. The above alkynyl groups may include ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-methylpent-2-ynyl, etc. The term “(C3-C30)cycloalkyl” means a monocyclic hydrocarbon or polycyclic hydrocarbon having 3 to 30 carbon atoms in the ring skeleton, wherein the number of carbon atoms is preferably 3 to 20, and more preferably 3 to 7. The above cycloalkyl groups may include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc. The term “(3- to 7-membered)heterocycloalkyl” means a cycloalkyl group having 3 to 7, preferably 5 to 7, ring skeleton atoms and containing at least one heteroatom selected from the group consisting of B, N, O, S, Si, and P, and preferably consisting of the group of O, S, and N. The above heterocycloalkyl groups may include tetrahydrofuran, pyrrolidine, tetrahydrothiophene (thiolan), tetrahydropyran, etc. The term “(C6-C30)aryl” means a monocyclic or fused-ring group derived from an aromatic hydrocarbon having 6 to 30 carbon atoms in the ring skeleton, wherein the number of carbon atoms in the ring skeleton is preferably 6 to 25, more preferably 6 to 18. The above aryl groups may be partially saturated and may contain a spiro structure. The above aryl groups may include phenyl, biphenyl, terphenyl, naphthyl, binaphthyl, phenylnaphthyl, naphthylphenyl, phenylterphenyl, fluorenyl, phenylfluorenyl, benzofluorenyl, dibenzofluorenyl, phenanthryl, phenylphenanthryl, anthryl, indenyl, triphenylenyl, pyrenyl, tetracenyl, perylenyl, chrysenyl, naphthacenyl, fluoranthenyl, spirobifluorenyl, azulyl, etc.More specifically, the aryl group may include phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, benzanthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, 9-phenanthryl, naphthacenyl, pyrenyl, 1-chrysenyl, 2-chrysenyl, 3-chrysenyl, 4-chrysenyl, 5-chrysenyl, 6-chrysenyl, benzo[c]phenanthryl, benzo[g]chrysenyl, 1-triphenylenyl, 2-triphenylenyl, 3-triphenylenyl, 4-triphenylenyl, 1-fluorenyl, 2-fluorenyl, 3-fluorenyl, 4-fluorenyl, 9-fluorenyl, benzofluorenyl, dibenzofluorenyl, 2-biphenylyl, 3-biphenylyl, 4-biphenylyl, o-terphenyl-4-yl, m-terphenyl-4-yl, m-terphenyl-3-yl, m-terphenyl-2-yl, p-terphenyl-4-yl, p-terphenyl-3-yl, p-terphenyl-2-yl, m-quaterphenyl, 3-fluoranthenyl, 4-fluoranthenyl, 8-fluoranthenyl, 9-fluoranthenyl, benzofluoranthenyl, o-tolyl, m-tolyl, p-tolyl, 2,3-xylyl, 3,4-xylyl, 2,5-xylyl, mesityl, o-cumenyl, m-cumenyl, p-cumenyl, p-tert-butylphenyl, p-(2-phenylpropyl)phenyl, 4'-methylbiphenyl, 4"-tert-butyl-p-terphenyl-4-yl, 9,9-dimethyl-1-fluorenyl, 9,9-dimethyl-2-fluorenyl, 9,9-dimethyl-3-fluorenyl, 9,9-dimethyl-4-fluorenyl, 9,9-diphenyl-1-fluorenyl, 9,9-diphenyl-2-fluorenyl, 9,9-diphenyl-3-fluorenyl, 9,9-diphenyl-4-fluorenyl, etc.

[0027] As used herein, the term "(3- to 30-membered) heteroaryl" is an aryl having 3 to 30 ring skeleton atoms and including at least one, preferably 1 to 4, heteroatoms selected from the group consisting of B, N, O, S, Si, and P. The above heteroaryl can be monocyclic or a fused ring condensed with at least one benzene ring; it can be partially saturated; it can be a heteroaryl formed by connecting at least one heteroaryl or aryl to a heteroaryl via one or more single bonds; and it can contain a spiro structure. The above heteroaryl can include monocyclic heteroaryls such as furyl, thienyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, triazinyl, tetrazinyl, triazolyl, tetrazolyl, furazanyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, etc., and fused ring heteroaryls such as benzofuryl, benzothienyl, isobenzofuryl, dibenzofuryl, dibenzothienyl, benzonaphthofuryl, benzonaphthothienyl, benzimidazolyl, benzothiazolyl, naphthothiazolyl, benzisothiazolyl, benzisoxazolyl, benzoxazolyl, isoindolyl, indolyl, benzindolyl, indazolyl, benzothiadiazolyl, quinolinyl, isoquinolinyl, cinnolinyl, quinazolinyl, benzoquinazolinyl, quinoxalinyl, benzoquinoxalinyl, naphthyridinyl, carbazolyl, benzocarbazolyl, dibenzocarbazolyl, phenoxazinyl, phenothiazinyl, phenanthridinyl, benzodioxolyl, dihydroacridinyl, etc. More specifically, the heteroaryl can include 1-pyrrolyl, 2-pyrrolyl, 3-pyrrolyl, pyrazinyl, 2-pyridyl, 2-pyrimidinyl, 4-pyrimidinyl, 5-pyrimidinyl, 6-pyrimidinyl, 1,2,3-triazin-4-yl, 1,2,4-triazin-3-yl, 1,3,5-triazin-2-yl, 1-imidazolyl, 2-imidazolyl, 1-pyrazolyl, 1-indolinyl, 2-indolinyl, 3-indolinyl, 5-indolinyl, 6-indolinyl, 7-indolinyl, 8-indolinyl, 2-imidazopyridyl, 3-imidazopyridyl, 5-imidazopyridyl, 6-imidazopyridyl, 7-imidazopyridyl, 8-imidazopyridyl, 3-pyridyl, 4-pyridyl, 1-indolyl, 2-indolyl, 3-indolyl, 4-indolyl, 5-indolyl, 6-indolyl, 7-indolyl, 1-isoindolyl, 2-isoindolyl, 3-isoindolyl, 4-isoindolyl, 5-isoindolyl, 6-isoindolyl, 7-isoindolyl, 2-furyl, 3-furyl, 2-benzofuryl, 3-benzofuryl, 4-benzofuryl, 5-benzofuryl, 6-benzofuryl, 7-benzofuryl, 1-isobenzofuryl, 3-isobenzofuryl, 4-isobenzofuryl, 5-isobenzofuryl, 6-isobenzofuryl, 7-isobenzofuryl, 2-quinolinyl, 3-quinolinyl, 4-quinolinyl, 5-quinolinyl, 6-quinolinyl, 7-quinolinyl, 8-quinolinyl, 1-isoquinolinyl, 3-isoquinolinyl, 4-isoquinolinyl, 5-isoquinolinyl, 6-isoquinolinyl, 7-isoquinolinyl,8 - isoquinolyl, 2 - quinoxalinyl, 5 - quinoxalinyl, 6 - quinoxalinyl, 1 - carbazolyl, 2 - carbazolyl, 3 - carbazolyl, 4 - carbazolyl, 9 - carbazolyl, azacarbazolyl - 1 - yl, azacarbazolyl - 2 - yl, azacarbazolyl - 3 - yl, azacarbazolyl - 4 - yl, azacarbazolyl - 5 - yl, azacarbazolyl - 6 - yl, azacarbazolyl - 7 - yl, azacarbazolyl - 8 - yl, azacarbazolyl - 9 - yl, 1 - phenanthridinyl, 2 - phenanthridinyl, 3 - phenanthridinyl, 4 - phenanthridinyl, 6 - phenanthridinyl, 7 - phenanthridinyl, 8 - phenanthridinyl, 9 - phenanthridinyl, 10 - phenanthridinyl, 1 - acridinyl, 2 - acridinyl, 3 - acridinyl, 4 - acridinyl, 9 - acridinyl, 2 - oxazolyl, 4 - oxazolyl, 5 - oxazolyl, 2 - oxadiazolyl, 5 - oxadiazolyl, 3 - furazanyl, 2 - thienyl, 3 - thienyl, 2 - methylpyrrol - 1 - yl, 2 - methylpyrrol - 3 - yl, 2 - methylpyrrol - 4 - yl, 2 - methylpyrrol - 5 - yl, 3 - methylpyrrol - 1 - yl, 3 - methylpyrrol - 2 - yl, 3 - methylpyrrol - 4 - yl, 3 - methylpyrrol - 5 - yl, 2 - tert - butylpyrrol - 4 - yl, 3-(2 - phenylpropyl)pyrrol - 1 - yl, 2 - methyl - 1 - indolyl, 4 - methyl - 1 - indolyl, 2 - methyl - 3 - indolyl, 4 - methyl - 3 - indolyl, 2 - tert - butyl - 1 - indolyl, 4 - tert - butyl - 1 - indolyl, 2 - tert - butyl - 3 - indolyl, 4 - tert - butyl - 3 - indolyl, 1 - dibenzofuranyl, 2 - dibenzofuranyl, 3 - dibenzofuranyl, 4 - dibenzofuranyl, 1 - dibenzothiophenyl, 2 - dibenzothiophenyl, 3 - dibenzothiophenyl, 4 - dibenzothiophenyl, 1 - silafluorenyl, 2 - silafluorenyl, 3 - silafluorenyl, 4 - silafluorenyl, 1 - germafluorenyl, 2 - germafluorenyl, 3 - germafluorenyl, 4 - germafluorenyl, etc. "Halogen" includes F, Cl, Br, and I.

[0028] In addition, "ortho (o - )", "meta (m - )", and "para (p - )" are prefixes that indicate the relative positions of substituents. Ortho indicates that two substituents are adjacent to each other, and for example, when two substituents in a benzene derivative occupy positions 1 and 2, it is called ortho. Meta indicates that two substituents are at positions 1 and 3, and for example, when two substituents in a benzene derivative occupy positions 1 and 3, it is called meta. Para indicates that two substituents are at positions 1 and 4, and for example, when two substituents in a benzene derivative occupy positions 1 and 4, it is called para.

[0029] As used herein, "substituted" in the expression "substituted or unsubstituted" means that a hydrogen atom in a functional group is replaced by another atom or another functional group (i.e., a substituent). The substituents of the substituted alkyl, substituted aryl, and substituted heteroaryl in R1 to R8 and Ar1 are each independently at least one selected from the group consisting of: deuterium; halogen; cyano; carboxyl; nitro; hydroxyl; (C1-C30)alkyl; halo(C1-C30)alkyl; (C2-C30)alkenyl; (C2-C30)alkynyl; (C1-C30)alkoxy; (C1-C30)alkylthio; (C3-C30)cycloalkyl; (C3-C30)cycloalkenyl; (3- to 7-membered)heterocycloalkyl; (C6-C30)aryloxy; (C6-C30)arylthio; unsubstituted or (3- to 30-membered)heteroaryl substituted by one or more (C6-C30)aryl; (C6-C30)aryl unsubstituted or substituted by at least one of (C1-C30)alkyl and (3- to 30-membered)heteroaryl; tri(C1-C30)alkylsilyl; tri(C6-C30)arylsilyl; di(C1-C30)alkyl(C6-C30)arylsilyl; (C1-C30)alkyldi(C6-C30)arylsilyl; amino; mono- or di-(C1-C30)alkylamino; mono- or di-(C6-C30)arylamino; (C1-C30)alkyl(C6-C30)arylamino; (C1-C30)alkylcarbonyl; (C1-C30)alkoxycarbonyl; (C6-C30)arylcarbonyl; di(C6-C30)arylboronyl; di(C1-C30)alkylboronyl; (C1-C30)alkyl(C6-C30)arylboronyl; (C6-C30)aryl(C1-C30)alkyl; and (C1-C30)alkyl(C6-C30)aryl. According to one embodiment of the present disclosure, the substituents are each independently at least one selected from the group consisting of (C1-C6)alkyl, (C6-C15)aryl, and (5- to 15-membered)heteroaryl. Specifically, the substituents can each independently be at least one selected from the group consisting of methyl, phenyl, naphthyl, biphenyl, and carbazolyl.

[0030] The compound represented by Formula 1 can be represented by any one of Formulas 1-1 to 1-3 below:

[0031]

[0032] wherein

[0033] R1 to R8, R9 to R 16 、Ar1, and D N are as defined in Formula 1, and

[0034] N represents an integer from 8 to 30.

[0035] In Formula 1, each of R1 to R8 independently represents hydrogen, deuterium, a halogen, a cyano group, a substituted or unsubstituted (C1-C30) alkyl group, a substituted or unsubstituted (C6-C30) aryl group, or a substituted or unsubstituted (5-membered to 30-membered) heteroaryl group, provided that one of R2 to R4 is bonded to In one embodiment of the present disclosure, one of R2 to R4 is bonded to and the others of R2 to R4, R1, and R5 to R8 each independently represent hydrogen or deuterium.

[0036] In Formula 1, Ar1 represents a substituted or unsubstituted (C6-C30) aryl group, or a substituted or unsubstituted (5-membered to 30-membered) heteroaryl group. In one embodiment of the present disclosure, Ar1 represents a substituted or unsubstituted (C6-C25) aryl group, or a substituted or unsubstituted (5-membered to 20-membered) heteroaryl group. In another embodiment of the present disclosure, Ar1 represents an unsubstituted (C6-C25) aryl group substituted with at least one of a (C1-C6) alkyl group, a (C6-C15) aryl group, and a (5-membered to 15-membered) heteroaryl group; or an unsubstituted (5-membered to 20-membered) heteroaryl group substituted with one or more (C6-C12) aryl groups. Specifically, Ar1 may represent phenyl, naphthyl, biphenyl, terphenyl, phenanthryl, naphthylphenyl, phenylnaphthyl, binaphthyl, biphenylnaphthyl, dimethylfluorenyl, dimethylbenzofluorenyl, carbazolylphenyl, carbazolylnaphthyl, phenylbenzothiazolyl, phenylbenzoxazolyl, dibenzothiophenyl, phenylcarbazolyl, phenylnaphthothiazolyl, benzonaphthofuranyl, phenylbenzocarbazolyl, 19-membered nitrogen-containing heteroaryl, etc.

[0037] In Formula 1, D N means that N hydrogen atoms in Formula 1 are replaced by deuterium. N represents an integer from 8 to 50, preferably an integer from 8 to 40, more preferably an integer from 8 to 30, and even more preferably an integer from 13 to 30. When deuterated with a number equal to or higher than the lower limit, the increase in the bond dissociation energy due to deuteration is sufficient to provide a significant increase in the lifetime characteristics. The upper limit is determined according to the number of hydrogen atoms that can be substituted in each compound.

[0038] In one embodiment of the present disclosure, in Formula 1, R1 to R8 not bonded to each independently represent hydrogen or deuterium; and Ar1 represents a substituted or unsubstituted (C6-C25) aryl group, or a substituted or unsubstituted (5-membered to 20-membered) heteroaryl group.

[0039] In another embodiment of the present disclosure, in Formula 1, R1 to R8 not bonded to Each of R1 to R8 independently represents hydrogen or deuterium; and Ar1 represents a (C6-C25) aryl group which is unsubstituted or substituted with at least one of (C1-C6) alkyl, (C6-C15) aryl, and (5- to 15-membered) heteroaryl; or a (5- to 20-membered) heteroaryl group which is unsubstituted or substituted with one or more (C6-C12) aryl groups.

[0040] In the formulas of the present disclosure, if adjacent substituents are connected to each other to form a ring, the ring may be a substituted or unsubstituted monocyclic or polycyclic (3- to 30-membered) alicyclic ring or aromatic ring, or a combination thereof, wherein the formed ring may contain at least one heteroatom selected from B, N, O, S, Si, and P, preferably N, O, and S. According to one embodiment of the present disclosure, the number of ring backbone atoms may be 5 to 20. According to another embodiment of the present disclosure, the number of ring backbone atoms may be 5 to 15. For example, the fused ring may be a substituted or unsubstituted dibenzothiophene ring, a substituted or unsubstituted dibenzofuran ring, a substituted or unsubstituted naphthalene ring, a substituted or unsubstituted phenanthrene ring, a substituted or unsubstituted fluorene ring, a substituted or unsubstituted benzothiophene ring, a substituted or unsubstituted benzofuran ring, a substituted or unsubstituted indole ring, a substituted or unsubstituted indene ring, a substituted or unsubstituted benzene ring, or a substituted or unsubstituted carbazole ring.

[0041] In the formulas of the present disclosure, each heteroaryl group independently may contain at least one heteroatom selected from B, N, O, S, Si, and P. In addition, the heteroatom may be bonded to at least one selected from the group consisting of hydrogen, deuterium, halogen, cyano, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (5- to 30-membered) heteroaryl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (C1-C30) alkoxy, substituted or unsubstituted tris(C1-C30) alkylsilyl, substituted or unsubstituted bis(C1-C30) alkyl(C6-C30) arylsilyl, substituted or unsubstituted (C1-C30) alkyldi(C6-C30) arylsilyl, substituted or unsubstituted tris(C6-C30) arylsilyl, substituted or unsubstituted mono- or di-(C1-C30) alkylamino, substituted or unsubstituted mono- or di-(C6-C30) arylamino, and substituted or unsubstituted (C1-C30) alkyl(C6-C30) arylamino.

[0042] The compounds represented by Formula 1 include, but are not limited to, the following compounds.

[0043]

[0044]

[0045] The compounds having Formula 1 according to the present disclosure can be prepared by synthetic methods known to those skilled in the art and, for example, as shown in the following reaction schemes, but are not limited thereto.

[0046] [Reaction Scheme 1]

[0047]

[0048] [Reaction Scheme 2]

[0049]

[0050] [Reaction Scheme 3]

[0051]

[0052] In Reaction Schemes 1 to 3, Ar1, R1 to R8, R9 to R 16 , and D N are as defined in Formula 1, and Hal represents a halogen.

[0053] In addition, non-deuterated derivatives of the compounds represented by Formula 1 can be prepared by known coupling or substitution reactions. Deuterated derivatives can be prepared by similar methods using deuterated precursor materials, or more generally, by treating non-deuterated compounds with deuterated solvents such as D6-benzene in the presence of Lewis acids such as aluminum trichloride or ethyl aluminum chloride, H / D exchange catalysts such as trifluoromethanesulfonic acid or trifluoromethanesulfonic acid-D, etc. In addition, the degree of deuteration can be controlled by changing reaction conditions such as reaction temperature. For example, by controlling the reaction temperature and time, acid equivalent, etc., the number of Ns in Formula 1 can be controlled.

[0054] Although the above describes illustrative synthesis examples of the compounds represented by Formula 1, those skilled in the art will be able to easily understand that they are all based on Buchwald-Hartwig cross-coupling reactions, N-arylation reactions, acidified montmorillonite (H-mont)-mediated etherification reactions, Miyaura borylation reactions, Suzuki cross-coupling reactions, intramolecular acid-induced cyclization reactions, Pd(II)-catalyzed oxidative cyclization reactions, Grignard reactions, Heck reactions, cyclic dehydration reactions, SN1 substitution reactions, SN2 substitution reactions, phosphine-mediated reductive cyclization reactions, etc., and even when substituents defined in Formula 1 above but not specified in the specific synthesis examples are bonded, the above reactions proceed.

[0055] The present disclosure provides an organic electroluminescent material comprising an organic electroluminescent compound represented by Formula 1, and an organic electroluminescent device comprising the organic electroluminescent material. The material may consist only of the organic electroluminescent compound according to the present disclosure, or may further comprise conventional materials included in the organic electroluminescent material.

[0056] The organic electroluminescent device according to the present disclosure includes a first electrode, a second electrode, and at least one organic layer between the first electrode and the second electrode, wherein the organic layer may comprise at least one organic electroluminescent compound represented by Formula 1.

[0057] One of the first electrode and the second electrode may be an anode, and the other may be a cathode. The organic layer may comprise a light-emitting layer, and may further comprise at least one layer selected from a hole injection layer, a hole transport layer, a hole assisting layer, a light-emitting assisting layer, an electron transport layer, an electron buffer layer, an electron injection layer, an intermediate layer, a hole blocking layer, and an electron blocking layer.

[0058] The second electrode may be a semi-transmissive reflective electrode or a reflective electrode, and depending on the type of material formed, the organic electroluminescent device may be a top-emitting type, a bottom-emitting type, or a double-sided emitting type.

[0059] The first electrode and the second electrode may each be formed of a transmissive conductive material, a semi-transmissive reflective conductive material, or a reflective conductive material. Depending on the type of material forming the first electrode and the second electrode, the organic electroluminescent device may be a top-emitting type, a bottom-emitting type, or a double-sided emitting type. In addition, the hole injection layer may be further doped with a p-type dopant, and the electron injection layer may be further doped with an n-type dopant.

[0060] The organic electroluminescent compound represented by Formula 1 of the present disclosure may be included in at least one of a light-emitting layer, a hole injection layer, a hole transport layer, a hole assisting layer, a light-emitting assisting layer, an electron transport layer, an electron buffer layer, an electron injection layer, an intermediate layer, a hole blocking layer, and an electron blocking layer. Preferably, it may be included in the light-emitting layer. When used in the light-emitting layer, the organic electroluminescent compound represented by Formula 1 of the present disclosure may be included as a host material. Preferably, the light-emitting layer may further comprise at least one dopant. If necessary, the organic electroluminescent compound of the present disclosure may be used as a co-host material. That is, the light-emitting layer may further comprise a compound other than the organic electroluminescent compound represented by Formula 1 of the present disclosure (the first host material) as a second host material. The weight ratio between the first host material and the second host material is from 1:99 to 99:1.

[0061] The dopant included in the organic electroluminescent device of the present disclosure is at least one phosphorescent dopant or fluorescent dopant, preferably at least one fluorescent dopant. The fluorescent dopant material applied to the organic electroluminescent device of the present disclosure is not particularly limited.

[0062] The organic layer may further include at least one compound selected from the group consisting of arylamine-based compounds and styrylarylamine-based compounds.

[0063] In addition, in the organic electroluminescent device of the present disclosure, the organic layer may further include at least one metal selected from the group consisting of metals of Group 1 of the periodic table, metals of Group 2, transition metals of the 4th period, transition metals of the 5th period, lanthanides, and organometals of d-transition elements, or at least one complex compound containing the metal.

[0064] In addition to the organic electroluminescent compound of the present disclosure, the organic electroluminescent device of the present disclosure can emit white light by further including at least one light-emitting layer containing a compound known in the art that emits blue light, red light, or green light. In addition, if necessary, it may further include a layer that emits yellow light or orange light.

[0065] In the organic electroluminescent device of the present disclosure, it is preferable to place at least one layer selected from a chalcogenide layer, a metal halide layer, and a metal oxide layer (hereinafter, "surface layer") on one or more inner surfaces of one or two electrodes. Specifically, it is preferable to place a chalcogenide (including oxide) layer of silicon or aluminum on the anode surface of the electroluminescent medium layer, and it is preferable to place a metal halide layer or a metal oxide layer on the cathode surface of the electroluminescent medium layer. The surface layer can provide operating stability for the organic electroluminescent device. Preferably, the chalcogenide includes SiO X (1 ≤ X ≤ 2), AlO X (1 ≤ X ≤ 1.5), SiON, SiAlON, etc.; the metal halide includes LiF, MgF2, CaF2, rare earth metal fluorides, etc.; and the metal oxide includes Cs2O, Li2O, MgO, SrO, BaO, CaO, etc.

[0066] A hole injection layer, a hole transport layer, or an electron blocking layer, or a combination thereof, can be used between the anode and the light-emitting layer. The hole injection layer can be multilayered to reduce the hole injection barrier (or hole injection voltage) from the anode to the hole transport layer or the electron blocking layer, and each of the multilayer can use two compounds simultaneously. The hole transport layer or the electron blocking layer can also be multilayered.

[0067] An electron buffer layer, a hole blocking layer, an electron transport layer, or an electron injection layer, or a combination thereof, may be used between the light-emitting layer and the cathode. The electron buffer layer may be multilayered to control electron injection and improve the interfacial characteristics between the light-emitting layer and the electron injection layer, where each of the multilayers may use two compounds simultaneously. The hole blocking layer or the electron transport layer may also be multilayered, where each of the multilayers may use multiple compounds.

[0068] A light-emission assisting layer may be disposed between the anode and the light-emitting layer, or between the cathode and the light-emitting layer. When the light-emission assisting layer is disposed between the anode and the light-emitting layer, it may be used to facilitate hole injection and / or hole transport, or to prevent electron spillage. When the light-emission assisting layer is disposed between the cathode and the light-emitting layer, it may be used to facilitate electron injection and / or electron transport, or to prevent hole spillage. Additionally, a hole assisting layer may be disposed between the hole transport layer (or hole injection layer) and the light-emitting layer, and may effectively promote or limit the hole transport rate (or hole injection rate), thereby enabling control of charge balance. Further, an electron blocking layer may be disposed between the hole transport layer (or hole injection layer) and the light-emitting layer, and may block overflow electrons from the light-emitting layer and confine excitons in the light-emitting layer to prevent light leakage. When the organic electroluminescent device includes two or more hole transport layers, the further included hole transport layer may serve as a hole assisting layer or an electron blocking layer. The hole assisting layer and the electron blocking layer may serve to improve the efficiency and / or lifetime of the organic electroluminescent device.

[0069] In the organic electroluminescent device of the present disclosure, a mixed region of an electron transport compound and a reducing dopant, or a mixed region of a hole transport compound and an oxidizing dopant is preferably disposed on at least one surface of a pair of electrodes. In this case, the electron transport compound is reduced to an anion, and thus it becomes easier to inject and transport electrons from the mixed region into the electroluminescent medium. Further, the hole transport compound is oxidized to a cation, and thus it becomes easier to inject and transport holes from the mixed region into the electroluminescent medium. Preferably, the oxidizing dopant includes various Lewis acids and acceptor compounds; and the reducing dopant includes alkali metals, alkali metal compounds, alkaline earth metals, rare earth metals, and mixtures thereof. The reducing dopant layer may be used as a charge generation layer to fabricate an organic electroluminescent device having two or more light-emitting layers that emit white light.

[0070] According to one embodiment of the present disclosure, the organic electroluminescent material can be used as a luminescent material for a white organic light-emitting device. Depending on the arrangement of R (red), G (green), B (blue), or YG (yellow-green) light-emitting units, white organic light-emitting devices having various structures have been proposed, such as a parallel side-by-side arrangement method, a stacked arrangement method, or a CCM (color conversion material) method, etc. In addition, according to one embodiment of the present disclosure, the organic electroluminescent material can also be applied to an organic electroluminescent device including QD (quantum dot).

[0071] To form each layer of the organic electroluminescent device of the present disclosure, a dry film-forming method such as vacuum evaporation, sputtering, plasma, ion plating, etc., or a wet film-forming method such as inkjet printing, spin coating, dip coating, flow coating, etc. can be used.

[0072] When using the wet film-forming method, a thin film can be formed by dissolving or dispersing the material for forming each layer in any suitable solvent such as ethanol, chloroform, tetrahydrofuran, dioxane, etc. There is no particular limitation on the solvent as long as the material for forming each layer is soluble or dispersible in the solvent and this does not cause any problems when forming the film.

[0073] A display system, such as a display system for a smartphone, a tablet computer, a laptop computer, a PC, a TV, or an automobile, or a lighting system, such as an outdoor or indoor lighting system, can be produced by using the organic electroluminescent device of the present disclosure.

[0074] Hereinafter, the preparation method of the compounds of the present disclosure, the characteristics of the compounds, and the luminescence characteristics of the organic electroluminescent device containing the compounds will be described in detail with reference to representative compounds of the present disclosure. However, the present disclosure is not limited to the following examples.

[0075] Example 1: Preparation of Compound C-1

[0076]

[0077] 3.5 g of Compound 1 (8.3 mmol) and 100 mL of benzene-D6 were introduced into a flask and heated to dissolve all of Compound 1. After cooling the mixture to room temperature, 4.4 mL of trifluoromethanesulfonic acid (49.8 mmol) was added thereto. After stirring the mixture at room temperature for 2 hours and 30 minutes, 20 mL of heavy water was added thereto. After stirring for 10 minutes, the mixture was neutralized with an aqueous K3PO4 solution. The organic layer was extracted with dichloromethane and the remaining moisture was removed using magnesium sulfate. The obtained organic layer was distilled under reduced pressure and separated by column chromatography to obtain 1.5 g of Compound C-1 (yield: 41.3%). The number of substituted deuteriums was observed by molecular weight and NMR.

[0078] MW M.P. 437.61 279.2℃

[0079] Device Example 1: Production of an OLED Containing a Compound According to the Present Disclosure

[0080] The following is the production of an OLED containing an organic electroluminescent compound according to the present disclosure: The indium tin oxide (ITO) thin film (10 Ω / sq) (GEOMATEC CO., LTD., Japan) on the glass substrate used for the OLED was subjected to ultrasonic washing successively with acetone, ethanol, and distilled water, and then stored in isopropyl alcohol. The ITO substrate was mounted on the substrate holder of a vacuum vapor deposition apparatus. Compound HI-1 was introduced into the chamber of the vacuum vapor deposition apparatus, and then the pressure in the chamber of the apparatus was controlled to 10 -6 Torr. Thereafter, a current was applied to the chamber to evaporate the above-introduced material, thereby forming a first hole injection layer with a thickness of 60 nm on the ITO substrate. Next, compound HI-2 was introduced into another chamber of the vacuum vapor deposition apparatus, and the compound was evaporated by applying a current to the chamber, thereby forming a second hole injection layer with a thickness of 5 nm on the first hole injection layer. Then compound HT-1 was introduced into another chamber of the vacuum vapor deposition apparatus, and the compound was evaporated by applying a current to the chamber, thereby forming a first hole transport layer with a thickness of 20 nm on the second hole injection layer. Then compound HT-2 was introduced into another chamber of the vacuum vapor deposition apparatus, and the compound was evaporated by applying a current to the chamber, thereby forming a second hole transport layer with a thickness of 5 nm on the first hole transport layer. After forming the hole injection layer and the hole transport layer, the following is the formation of the light-emitting layer thereon: Compound C-1 as the host of the light-emitting layer was introduced into one chamber of the vacuum vapor deposition apparatus, and compound BD as the dopant was introduced into another chamber. The two materials were evaporated at different rates and the dopant was deposited at a doping amount of 2 wt% based on the total amount of the host and the dopant to form a light-emitting layer with a thickness of 20 nm on the second hole transport layer. Next, compound ET-1 and compound EI-1 were evaporated at a rate of 1:1 in two other chambers to deposit an electron transport layer with a thickness of 35 nm on the light-emitting layer. After depositing compound EI-1 as an electron injection layer with a thickness of 2 nm on the electron transport layer, an Al cathode with a thickness of 80 nm was deposited on the electron injection layer by another vacuum vapor deposition apparatus. Thus, an OLED was produced.

[0081] As a result, the shortest time required for the brightness to decrease from 100% to 95% at 2,000 nits was 76 hours.

[0082] Comparative Example 1: Production of an OLED Containing a Conventional Compound

[0083] An OLED was produced in the same manner as in Device Example 1, except that compound H-1 was used as the host material of the light-emitting layer.

[0084] As a result, the shortest time required for the luminance to decrease from 100% to 95% at 2,000 nits was 11 hours.

[0085] Comparative Example 2: Production of an OLED Containing a Conventional Compound

[0086] An OLED was produced in the same manner as in Device Example 1, except that compound H-2 was used as the host material of the light-emitting layer.

[0087] As a result, the shortest time required for the luminance to decrease from 100% to 95% at 2,000 nits was 25 hours.

[0088] Comparative Example 3: Production of an OLED Containing a Conventional Compound

[0089] An OLED was produced in the same manner as in Device Example 1, except that compound H-3 was used as the host material of the light-emitting layer.

[0090] As a result, the shortest time required for the luminance to decrease from 100% to 95% at 2,000 nits was 13 hours.

[0091]

[0092] In the present disclosure, an organic electroluminescent device was produced by substituting hydrogen of the host compound of the light-emitting layer with deuterium, and it can be seen that the lifetime characteristics are far superior to those of an organic electroluminescent device using a conventional compound as the host. It should be understood that this improvement in the lifetime characteristics of the OLED is due to the improvement in material stability compared to a non-deuterated or less deuterated compound, and this improvement in stability is due to the reduction in the zero-point vibrational energy of the deuterated compound. In addition, without being bound by theory, in order to improve the lifetime of a fluorescent organic electroluminescent device that emits blue light, it is necessary to control the electron mobility, and since dibenzofuran has a faster hole migration than aryl, a similar effect of reducing the electron mobility can be obtained. Without being bound by theory, the reduction in electron mobility can lead to a reduction in the degradation of adjacent layers, thereby increasing the lifetime. In terms of such an effect, deuterating a compound in which anthracene is substituted with dibenzofuran may be advantageous compared to deuterating a compound in which anthracene is substituted with aryl.

Claims

1. An organic electroluminescent compound represented by the following Formula 1: Wherein R1 to R8 represent hydrogen, provided that one of R2 to R4 is bonded to R9 to R 16 each independently represents hydrogen or deuterium; Ar1 represents a deuterium-substituted or unsubstituted phenylnaphthyl or a deuterium-substituted or unsubstituted naphthylphenyl; D N means that N hydrogen atoms are replaced by deuterium; and N represents an integer from 8 to 30.

2. The organic electroluminescent compound according to claim 1, wherein Formula 1 is represented by any one of the following Formulas 1-1 to 1-3: Wherein R1 to R8, R9 to R 16 , Ar1, and D N are as defined in claim 1; and N represents an integer from 8 to 30.

3. The organic electroluminescent compound according to claim 1, wherein N represents an integer from 13 to 30.

4. The organic electroluminescent compound according to claim 1, wherein, The compound represented by Formula 1 is selected from the group consisting of the following compounds:

5. An organic electroluminescent material comprising the organic electroluminescent compound according to Claim 1.

6. An organic electroluminescent device comprising the organic electroluminescent compound according to Claim 1.

7. The organic electroluminescent device according to claim 6, wherein, The organic electroluminescent compound is included in the light-emitting layer.

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