Organic electroluminescent compounds and organic electroluminescent devices containing the same

Abstract

To provide an organic electroluminescent compound that is effective for producing an organic electroluminescent device having excellent life characteristics. We have found that deuteration of organic electroluminescent compounds having a specific structure of Formula 1 results in a more significant improvement in lifetime compared to anthracene compounds having other structures. By attaching a heteroaryl instead of an aryl to the anthracene core, the mobility of holes and / or electrons can be improved, thereby reducing the driving voltage. TIFF2026041838000022.tif41170

Description

[Technical Field]

[0001] The present disclosure relates to organic electroluminescent compounds and organic electroluminescent devices containing the same. [Background technology]

[0002] Electroluminescent (EL) devices are self-emitting devices that have the advantages of providing a wider viewing angle, a larger contrast ratio, and a faster response time. In 1987, Eastman Kodak developed the first organic EL device by using small aromatic diamine molecules and aluminum complexes as materials for forming the light-emitting layer [Appl. Phys. Lett. 51, 913, 1987].

[0003] Organic electroluminescent devices (OLEDs) convert electrical energy into light by applying electricity to organic light-emitting materials and typically include an anode, a cathode, and organic layers formed between the two electrodes. The organic layers of an OLED may include a hole-injection layer, a hole-transport layer, a hole-assisting layer, an emitting-assisting layer, an electron-blocking layer, an emitting layer (containing a host material and a dopant material), an electron buffer layer, a hole-blocking layer, an electron-transport layer, an electron-injection layer, etc. Materials used in the organic layers can be classified according to their functions into hole-injection materials, hole-transport materials, hole-assisting materials, emitting-assisting materials, electron-blocking materials, emitting materials, electron buffer materials, hole-blocking materials, electron-transport materials, electron-injection materials, etc. In an OLED, upon application of a voltage, holes are injected from the anode into the emitting layer, and electrons are injected from the cathode into the emitting layer, and high-energy excitons are formed by the recombination of the holes and electrons. This energy causes the organic luminescent compound to reach an excited state, and light emission occurs when the organic luminescent compound emits light from the energy due to the excited state returning to the ground state.

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

[0005] Therefore, in order to realize a full-color display, it is necessary to develop a deep blue light-emitting material with a long lifetime and other organic materials that have suitable energy levels together with the blue light-emitting material.

[0006] U.S. Patent No. 8,759,818 and U.S. Patent Application Publication No. 2014 / 0001459 disclose organic electroluminescent compounds that contain an anthracene moiety in which some hydrogen atoms are replaced with deuterium. However, these references do not specifically disclose organic electroluminescent compounds that contain an anthracene moiety in which some hydrogen atoms are replaced with deuterium and in which dibenzofuran is substituted at a specific position. Summary of the Invention [Problem to be solved by the invention]

[0007] The object of the present disclosure is, first, to provide an organic electroluminescent compound that is effective for producing an organic electroluminescent device having excellent life characteristics, and, second, to provide an organic electroluminescent device including the organic electroluminescent compound. [Means for solving the problem]

[0008] Improvement of blue-emitting materials or devices is important for organic electroluminescent devices. However, since the early development of organic electroluminescent devices, compounds containing a primary anthracene moiety have remained the blue host material. This has limited the improvement of the lifetime characteristics of blue-emitting materials or devices. To improve the lifetime characteristics, the stability of the anthracene compound contained in the blue host material can be increased. One method is deuteration. Deuteration of an anthracene compound can lower the zero-point vibrational energy of the compound, thereby increasing the bond dissociation energy (BDE) of the compound. As a result, the stability of the anthracene compound can be improved. Figure 1 is a graph showing the increase in bond dissociation energy with deuteration. Specifically, the inventors have found that deuteration of organic electroluminescent compounds having a specific structure of Formula 1 below results in a more significant improvement in lifetime compared to anthracene compounds having other structures. By attaching a heteroaryl group instead of an aryl group to the anthracene core, hole and / or electron mobility can be improved, thereby reducing the driving voltage. [ka] During the ceremony, R1 to R8 each independently represent hydrogen, deuterium, halogen, cyano, substituted or unsubstituted (C1 to C30) alkyl, substituted or unsubstituted (C6 to C30) aryl, or substituted or unsubstituted (5 to 30 membered) heteroaryl, provided that one of R2 to R4 is [ka] provided that it is bound to; R9~R 16 each independently represents hydrogen or deuterium; Ar1 represents a substituted or unsubstituted (C6 to C30) aryl or a substituted or unsubstituted (5 to 30-membered) heteroaryl; D Nmeans that N hydrogen atoms are replaced by deuterium; N represents an integer of 8 to 50.

[0009] Effect of the invention By using the organic electroluminescent compounds according to the present disclosure, it is possible to fabricate organic electroluminescent devices with improved blue emission lifetime. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a graph showing the increase in bond dissociation energy due to deuteration. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present disclosure will be described in detail below. However, the following description is intended to illustrate the present invention and is not meant to limit the scope of the present invention in any way.

[0012] 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 that constitutes the organic electroluminescent device as needed.

[0013] The term "organic electroluminescent material" in this disclosure refers to a material that can be used in an organic electroluminescent device and can include at least one compound. The organic electroluminescent material can be included in any layer that constitutes an organic electroluminescent device, as needed. For example, the organic electroluminescent material can be a hole injection material, a hole transport material, a hole auxiliary material, a light-emitting auxiliary material, an electron blocking material, a light-emitting material, an electron buffer material, a hole blocking material, an electron transport material, an electron injection material, etc.

[0014] The organic electroluminescent material of the present disclosure may include at least one compound represented by Formula 1. The compound represented by Formula 1 may be included in an emitting layer or a hole transporting layer, but is not limited thereto. For example, when included in an emitting layer, the compound represented by Formula 1 may be included as a host, such as a host for blue light emission. According to one embodiment of the present disclosure, the compound of Formula 1 may be a fluorescent host, for example, a fluorescent host for blue light emission.

[0015] Compounds of formula 1 are described in more detail herein below.

[0016] As used herein, the term "(C1-C30) alkyl" refers to a straight-chain or branched alkyl having 1 to 30 carbon atoms constituting the chain, preferably 1 to 20, and more preferably 1 to 10. Examples of the alkyl include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and tert-butyl. The term "(C2-C30) alkenyl" refers to a straight-chain or branched alkenyl having 2 to 30 carbon atoms constituting the chain, preferably 2 to 20, and more preferably 2 to 10. Examples of the alkenyl include vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, and 2-methylbut-2-enyl. The term "(C2-C30)alkynyl" refers to a straight-chain or branched alkynyl having 2 to 30 carbon atoms constituting the chain, preferably 2 to 20, more preferably 2 to 10. Examples of the alkynyl include ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, and 1-methylpent-2-ynyl. The term "(C3-C30)cycloalkyl" refers to a monocyclic or polycyclic hydrocarbon having 3 to 30 ring skeletal carbon atoms, preferably 3 to 20, more preferably 3 to 7. Examples of the cycloalkyl include cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. The term "(3- to 7-membered)heterocycloalkyl" refers to a cycloalkyl having 3 to 7, preferably 5 to 7, ring skeletal atoms and containing at least one heteroatom selected from the group consisting of B, N, O, S, Si, and P, preferably the group consisting of O, S, and N. The heterocycloalkyl may include tetrahydrofuran, pyrrolidine, thiolane, tetrahydropyran, etc. The term "(C6-C30)aryl" refers to a monocyclic or fused ring radical derived from an aromatic hydrocarbon having 6 to 30 ring skeletal carbon atoms, preferably 6 to 25, more preferably 6 to 18 ring skeletal carbon atoms. The aryl may be partially saturated and may include a spiro structure.The aryl may include phenyl, biphenyl, terphenyl, naphthyl, binaphthyl, phenylnaphthyl, naphthylphenyl, phenylterphenyl, fluorenyl, phenylfluorenyl, benzofluorenyl, dibenzofluorenyl, phenanthrenyl, phenylphenanthrenyl, anthracenyl, indenyl, triphenylenyl, pyrenyl, tetracenyl, perylenyl, chrysenyl, naphthacenyl, fluoranthenyl, spirobifluorenyl, azulenyl, and the like.More specifically, aryl includes 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, Lysenyl, 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, m-terphenyl-4-yl, m-terphenyl-3-yl, m-terphenyl-2-yl, p-terphenyl phenyl-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, pt-butylphenyl, p-(2-phenylpropyl) phenyl, 4'-methylbiphenyl, 4"-t-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, and the like.

[0017] As used herein, the term "(3- to 30-membered)heteroaryl" refers to an aryl group having 3 to 30 skeletal ring atoms and containing at least one, preferably 1 to 4, heteroatoms selected from the group consisting of B, N, O, S, Si, and P. The heteroaryl may be a monocyclic ring or a fused ring fused with at least one benzene ring; may be partially saturated; may be formed by linking at least one heteroaryl or aryl group to a heteroaryl group via a single bond; or may include a spiro structure. Examples of the heteroaryl include monocyclic heteroaryls such as furyl, thiophenyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, triazinyl, tetrazinyl, triazolyl, tetrazolyl, furazanyl, pyridyl, pyrazinyl, pyrimidinyl, and pyridazinyl, as well as benzofuranyl, benzothiophenyl, isobenzofuranyl, dibenzofuranyl, dibenzothiophenyl, benzonaphthofuranyl, benzonaphthothiophenyl, benzimidazolyl, and benzyl. Examples of fused ring heteroaryls include benzothiazolyl, naphthothiazolyl, benzisothiazolyl, benzisoxazolyl, benzoxazolyl, isoindolyl, indolyl, benzoindolyl, indazolyl, benzothiadiazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl, benzoquinazolinyl, quinoxalinyl, benzoquinoxalinyl, naphthyridinyl, carbazolyl, benzocarbazolyl, dibenzocarbazolyl, phenoxazinyl, phenothiazinyl, phenanthridinyl, benzodioxolyl, and dihydroacridinyl. More specifically, heteroaryl includes 1-pyrrolyl, 2-pyrrolyl, 3-pyrrolyl, pyrazinyl, 2-pyridinyl, 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-indolizinyl, 2-indolizinyl, 3-indolizinyl, 5-indolizinyl, 6-indolizinyl, 7-indolizinyl, 8-indolizinyl, 2-imidazopyridinyl, 3-imidazopyridinyl,5-Imidazopyridinyl, 6-Imidazopyridinyl, 7-Imidazopyridinyl, 8-Imidazopyridinyl, 3-Pyridinyl, 4-Pyridinyl, 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-Benzofuranyl, 3-Benzofuranyl, 4-Benzofuranyl, 5-Benzofuranyl, 6-Benzofuranyl Quinolyl, 7-benzofuranyl, 1-isobenzofuranyl, 3-isobenzofuranyl, 4-isobenzofuranyl, 5-isobenzofuranyl, 6-isobenzofuranyl, 7-isobenzofuranyl, 2-quinolyl, 3-quinolyl, 4-quinolyl, 5-quinolyl, 6-quinolyl, 7-quinolyl, 8-quinolyl, 1-isoquinolyl, 3-isoquinolyl, 4-isoquinolyl, 5-isoquinolyl, 6-isoquinolyl, 7-isoquinolyl, 8-isoquinolyl, 2-quinoxalinyl, 5-quinoxalinyl, 6-quinoxalinyl, 1-carbazolyl, 2-carbazolyl, 3- Carbazolyl, 4-carbazolyl, 9-carbazolyl, azacarbazol-1-yl, azacarbazol-2-yl, azacarbazol-3-yl, azacarbazol-4-yl, azacarbazol-5-yl, azacarbazol-6-yl, azacarbazol-7-yl, azacarbazol-8-yl, azacarbazol-9-yl, 1-phenanthridinyl, 2-phenanthridinyl, 3-phenanthridinyl, 4-phenanthridinyl, 6-phenanthridinyl, 7-phenanthridinyl, 8-phenanthridinyl, 9-phenanthridinyl, 1 0-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-t-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-t-butyl-1-indolyl, 4-t-butyl-1-indolyl, 2-t-butyl-3-indolyl, 4-t-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, and the like may be mentioned. "Halogen" includes F, Cl, Br, and I.

[0018] Additionally, "ortho (o-)," "meta (m-)," and "para (p-)" are prefixes that indicate the relative positions of substituents, respectively. Ortho indicates that two substituents are adjacent to each other; for example, when two substituents in a benzene derivative occupy the 1st and 2nd positions, it is called the ortho position. Meta indicates that two substituents are at the 1st and 3rd positions; for example, when two substituents in a benzene derivative occupy the 1st and 3rd positions, it is called the meta position. Para indicates that two substituents are at the 1st and 4th positions; for example, when two substituents in a benzene derivative occupy the 1st and 4th positions, it is called the para position.

[0019] As used herein, the term "substituted" in the expression "substituted or unsubstituted" means that a hydrogen atom in a particular functional group is replaced with 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 deuterium; halogen; cyano; carboxyl; nitro; hydroxyl; (C1 to C30) alkyl; halo(C1 to C30) alkyl; (C2 to C30) alkenyl; (C2 to C30) alkynyl; (C1 to C30) alkoxy; (C1 to C30) alkylthio; (C3 to C30) cycloalkyl; (C3 to C30) cycloalkenyl; (3 to 7-membered) heterocycloalkyl; (C6 to C30) aryloxy; (C6 to C30) arylthio; (3 to 30-membered) heteroaryl unsubstituted or substituted with (C6 to C30) aryl; (C6 to C30) aryl unsubstituted or substituted with at least one of (C1 to C30) alkyl and (3 to 30-membered) heteroaryl; tri(C 1-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)alkylca The substituents are at least one selected from the group consisting of: carbonyl; (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 (5-15 membered) heteroaryl. Specifically, the substituents may each independently be at least one selected from the group consisting of methyl, phenyl, naphthyl, biphenyl, and carbazolyl.

[0020] The compound represented by formula 1 can be represented by any one of formulas 1-1 to 1-3 below: [ka] (In the formula, R1 to R8, R9 to R 16 , Ar1, and D N is as defined in Equation 1, N represents an integer between 8 and 30.

[0021] In Formula 1, R1 to R8 each independently represent hydrogen, deuterium, halogen, cyano, substituted or unsubstituted (C1 to C30) alkyl, substituted or unsubstituted (C6 to C30) aryl, or substituted or unsubstituted (5 to 30 membered) heteroaryl, and one of R2 to R4 is [ka] In one embodiment of the present disclosure, one of R2 to R4 is [ka] The remainder of R2 to R4, R1, and R5 to R8 each independently represent hydrogen or deuterium.

[0022] In Formula 1, Ar1 represents a substituted or unsubstituted (C6-C30) aryl or a substituted or unsubstituted (5-30 membered) heteroaryl. In one embodiment of the present disclosure, Ar1 represents a substituted or unsubstituted (C6-C25) aryl or a substituted or unsubstituted (5-20 membered) heteroaryl. In another embodiment of the present disclosure, Ar1 represents a (C6-C25) aryl that is unsubstituted or substituted with at least one of a (C1-C6) alkyl, a (C6-C15) aryl, and a (5-15 membered) heteroaryl; or a (5-20 membered) heteroaryl that is unsubstituted or substituted with a (C6-C12) aryl. Specifically, Ar1 may represent phenyl, naphthyl, biphenyl, terphenyl, phenanthrenyl, naphthylphenyl, phenylnaphthyl, binaphthyl, biphenylnaphthyl, dimethylfluorenyl, dimethylbenzofluorenyl, carbazolylphenyl, carbazolylnaphthyl, phenylbenzothiazolyl, phenylbenzoxazolyl, dibenzothiophenyl, phenylcarbazolyl, phenylnaphthothiazolyl, benzonaphthofuranyl, phenylbenzocarbazolyl, 19-membered nitrogen-containing heteroaryl, and the like.

[0023] In Equation 1, D N means that N hydrogen atoms in formula 1 are substituted with deuterium. N represents an integer of 8 to 50, preferably an integer of 8 to 40, more preferably an integer of 8 to 30, and even more preferably an integer of 13 to 30. When deuteration is performed to a number equal to or greater than the lower limit, the increase in bond dissociation energy due to deuteration is sufficient to significantly improve the life characteristics. The upper limit is determined depending on the number of substitutable hydrogen atoms in each compound.

[0024] In one embodiment of the present disclosure, in Formula 1: [ka] R1 to R8 that are not bonded to each independently represent hydrogen or deuterium; Ar1 ​​represents a substituted or unsubstituted (C6 to C25) aryl or a substituted or unsubstituted (5 to 20 membered) heteroaryl.

[0025] In another embodiment of the present disclosure, in Formula 1: [ka] R1 to R8 that are not bonded to each independently represent hydrogen or deuterium; Ar1 ​​represents a (C6-C25)aryl that is unsubstituted or substituted with at least one of a (C1-C6)alkyl, a (C6-C15)aryl, and a (5- to 15-membered)heteroaryl; or a (5- to 20-membered)heteroaryl that is unsubstituted or substituted with a (C6-C12)aryl.

[0026] In the formula of the present disclosure, when adjacent substituents are bonded to each other to form a ring, this ring may be a substituted or unsubstituted monocyclic or polycyclic (3 to 30 membered) alicyclic ring or aromatic ring, or a combination thereof, and 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 skeletal atoms may be 5 to 20. According to another embodiment of the present disclosure, the number of ring skeletal 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.

[0027] In the formulas of the present disclosure, heteroaryls may each independently contain at least one heteroatom selected from B, N, O, S, Si, and P. In addition, the heteroatom may be selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (5-30 membered) heteroaryl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (C1-C30) alkoxy, substituted or unsubstituted tri(C1-C30) alkylsilyl, substituted or unsubstituted di(C1-C30) alkyl(C6-C30) aryl. and substituted or unsubstituted (C1-C30) alkyl(C6-C30)arylsilyl, substituted or unsubstituted (C1-C30) alkyldi(C6-C30)arylsilyl, substituted or unsubstituted tri(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.

[0028] Compounds represented by formula 1 include, but are not limited to, the following compounds: [ka] [ka] [ka]

[0029] Compounds of Formula 1 according to the present disclosure can be prepared by synthetic methods known to those skilled in the art, for example, but not limited to, as shown in the following reaction schemes.

[0030] [Reaction Scheme 1] [ka]

[0031] [Reaction Scheme 2] [ka]

[0032] [Reaction Scheme 3] [ka]

[0033] In Reaction Schemes 1 to 3, Ar1, R1 to R8, R9 to R 16 , and D N is as defined in Formula 1, and Hal represents a halogen.

[0034] In addition, non-deuterated derivatives of compounds represented by Formula 1 can be prepared by known coupling or substitution reactions. Deuterated derivatives can be prepared by analogous methods using deuterated precursor materials, or more commonly, by treating non-deuterated compounds with deuterated solvents, such as D6-benzene, in the presence of Lewis acids, such as aluminum trichloride or ethylaluminum chloride, H / D exchange catalysts, such as trifluoromethanesulfonic acid or trifluoromethanesulfonic acid-D, or the like. Furthermore, the degree of deuteration can be controlled by varying reaction conditions, such as reaction temperature. For example, the number of N in Formula 1 can be controlled by controlling the reaction temperature and time, acid equivalents, etc.

[0035] Illustrative synthetic examples of the compound represented by Formula 1 have been described above, but those skilled in the art will readily understand that all of them are based on Buchwald-Hartwig cross-coupling reactions, N-arylation reactions, 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, cyclodehydration reactions, SN1 substitution reactions, SN2 substitution reactions, phosphine-mediated reductive cyclization reactions, etc., and that the above reactions will proceed even when substituents defined in Formula 1 above, which are not specified in the specific synthetic examples, are attached.

[0036] 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 solely of the organic electroluminescent compound according to the present disclosure, or may further comprise conventional materials contained in organic electroluminescent materials.

[0037] 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 include at least one organic electroluminescent compound represented by Formula 1.

[0038] One of the first and second electrodes may be an anode, and the other may be a cathode. The organic layer may include an emitting layer, and may further include at least one layer selected from a hole injection layer, a hole transport layer, a hole auxiliary layer, an emitting auxiliary 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.

[0039] The second electrode can be a semi-transparent electrode or a reflective electrode, and the organic electroluminescent device can be top-emitting, bottom-emitting, or double-sided emitting depending on the type of material from which it is formed.

[0040] The first electrode and the second electrode can be formed of a transparent conductive material, a semi-transparent conductive material, or a reflective conductive material, respectively. The organic electroluminescent device can be a top-emitting type, a bottom-emitting type, or a double-sided emitting type according to the type of material forming the first electrode and the second electrode. In addition, the hole injection layer can be further doped with a p-type dopant, and the electron injection layer can be further doped with an n-type dopant.

[0041] The organic electroluminescent compound represented by Formula 1 of the present disclosure may be included in at least one of the light-emitting layer, hole-injection layer, hole-transport layer, hole-assisting layer, light-emitting auxiliary layer, electron-transport layer, electron buffer layer, electron-injection layer, intermediate layer, hole-blocking layer, and electron-blocking layer, and is preferably 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 include 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 include a compound other than the organic electroluminescent compound represented by Formula 1 of the present disclosure (first host material) as a second host material. The weight ratio between the first host material and the second host material is in the range of 1:99 to 99:1.

[0042] The dopant contained in the organic electroluminescent device of the present disclosure is at least one phosphorescent or fluorescent dopant, preferably at least one phosphorescent dopant.The fluorescent dopant material applied to the organic electroluminescent device of the present disclosure is not particularly limited.

[0043] The organic layer may further contain at least one compound selected from the group consisting of arylamine compounds and styrylarylamine compounds.

[0044] In addition, in the organic electroluminescent device of the present disclosure, the organic layer may further comprise at least one metal selected from the group consisting of metals of Group 1, metals of Group 2, transition metals of Periodic Table, transition metals of Period 4, transition metals of Period 5, lanthanides of d-transition elements and organometallics, or at least one complex compound containing said metal.

[0045] The organic electroluminescent device of the present disclosure can emit white light by further comprising at least one light-emitting layer containing the blue, red or green light-emitting compound known in the art in addition to the organic electroluminescent compound of the present disclosure.In addition, it can further comprise a yellow or orange light-emitting layer as needed.

[0046] In the organic electroluminescent device of the present disclosure, at least one layer selected from a chalcogenide layer, a metal halide layer, and a metal oxide layer (hereinafter referred to as a "surface layer") may be preferably disposed on the inner surface of one or both electrodes. Specifically, a silicon or aluminum chalcogenide (including oxide) layer is preferably disposed on the anode side of the electroluminescent medium layer, and a metal halide or metal oxide layer is preferably disposed on the cathode side of the electroluminescent medium layer. The surface layer may provide operational stability to the organic electroluminescent device. Preferably, the chalcogenide is SiO X (1≦X≦2), AlO X (1≦X≦1.5), SiON, SiAlON, etc.; metal halides include LiF, MgF2, CaF2, rare earth metal fluorides, etc.; metal oxides include Cs2O, Li2O, MgO, SrO, BaO, CaO, etc.

[0047] 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 a multilayer to lower the hole injection barrier (or hole injection voltage) from the anode to the hole transport layer or the electron blocking layer, where each of the multilayers can use two compounds simultaneously. The hole transport layer or the electron blocking layer can also be a multilayer.

[0048] An electron buffer layer, a hole blocking layer, an electron transport layer, or an electron injection layer, or a combination thereof, can be used between the light-emitting layer and the cathode. The electron buffer layer can be multilayered to control electron injection and improve the interfacial properties between the light-emitting layer and the electron injection layer, where each layer can simultaneously use two compounds. The hole blocking layer or electron transport layer can also be multilayered, and each layer can use multiple compounds.

[0049] The light-emitting auxiliary layer can be disposed between the anode and the light-emitting layer or between the cathode and the light-emitting layer. When disposed between the anode and the light-emitting layer, it can be used to promote hole injection and / or hole transport or to prevent electron overflow. When disposed between the cathode and the light-emitting layer, it can be used to promote electron injection and / or electron transport or to prevent hole overflow. In addition, the hole auxiliary layer can be disposed between the hole transport layer (or hole injection layer) and the light-emitting layer and can be effective in promoting or blocking the hole transport rate (or hole injection rate), thereby allowing the charge balance to be controlled. Furthermore, the electron blocking layer can be disposed between the hole transport layer (or hole injection layer) and the light-emitting layer and can block electrons from overflowing from the light-emitting layer and confine excitons in the light-emitting layer to prevent light leakage. When an organic electroluminescent device includes two or more hole transport layers, the additional hole transport layers can be used as hole auxiliary layers or electron blocking layers. The hole assisting layer and the electron blocking layer may have the effect of improving the efficiency and / or lifetime of the organic electroluminescent device.

[0050] In the organic electroluminescent device of the present disclosure, a mixed region of an electron transport compound and a reductive dopant or a mixed region of a hole transport compound and an oxidative dopant is preferably disposed on the surface of at least one of a pair of electrodes. In this case, the electron transport compound is reduced to an anion, thereby making it easier to inject and transport electrons from the mixed region into the electroluminescent medium. Furthermore, the hole transport compound is oxidized to a cation, thereby making it easier to inject and transport holes from the mixed region into the electroluminescent medium. Preferably, the oxidative dopant includes various Lewis acids and acceptor compounds, and the reductive dopant includes alkali metals, alkali metal compounds, alkaline earth metals, rare earth metals, and mixtures thereof. An organic electroluminescent device having two or more light-emitting layers can be fabricated using a reductive dopant layer as a charge-generating layer, which emits white light.

[0051] The organic electroluminescent material according to an embodiment of the present disclosure can be used as a light-emitting material for a white organic light-emitting device. White organic light-emitting devices have been proposed in various structures, such as parallel side-by-side arrangement, stacking arrangement, or CCM (color conversion material) arrangement, according to the arrangement of R (red), G (green), B (blue), or YG (yellowish green) light-emitting units. In addition, the organic electroluminescent material according to an embodiment of the present disclosure can also be applied to organic electroluminescent devices containing QDs (quantum dots).

[0052] To form each layer of the organic electroluminescent device of the present disclosure, dry film formation methods such as vacuum evaporation, sputtering, plasma, ion plating, etc., or wet film formation methods such as inkjet printing, spin coating, dip coating, flow coating, etc. can be used.

[0053] When using a wet film-forming method, a thin film can be formed by dissolving or dispersing the materials forming each layer in any suitable solvent such as ethanol, chloroform, tetrahydrofuran, dioxane, etc. The solvent is not particularly limited as long as the materials forming each layer are soluble or dispersible in a solvent that does not cause any problems in forming a film.

[0054] By using the organic electroluminescent devices of the present disclosure, it is possible to manufacture display systems, such as display systems for smartphones, tablets, notebooks, PCs, TVs, or automobiles, or lighting systems, such as outdoor or indoor lighting systems.

[0055] Hereinafter, the preparation method of the compound of the present disclosure, its properties, and the light-emitting properties of the organic electroluminescent device containing it will be described in detail with respect to the representative compound of the present disclosure.However, the present disclosure is not limited to the following examples. [Example]

[0056] Example 1: Preparation of Compound C-1 [ka] 3.5 g of compound 1 (8.3 mmol) and 100 mL of benzene-D6 were placed in a flask and heated to dissolve all of compound 1. After the mixture was cooled to room temperature, 4.4 mL of triflic acid (49.8 mmol) was added. The mixture was stirred at room temperature for 2 hours and 30 minutes, and then 20 mL of deuterium oxide was added. After stirring for 10 minutes, the mixture was neutralized with an aqueous solution of K3PO4. The organic layer was extracted with dichloromethane, and residual water was removed using magnesium sulfate. The resulting 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 deuterium atoms was monitored using molecular weight and NMR.

[0057] [Table 1]

[0058] Device Example 1: Fabrication of an OLED Comprising a Compound According to the Present Disclosure An OLED containing an organic electroluminescent compound according to the present disclosure was fabricated as follows: A transparent electrode indium tin oxide (ITO) thin film (10 Ω / sq) (Geomatec Co., Ltd., Japan) on a glass substrate for the OLED was subjected to ultrasonic cleaning in acetone, ethanol, and distilled water, successively, and then stored in isopropanol. The ITO substrate was attached to a substrate holder of a vacuum evaporation system. Compound HI-1 was introduced into the cell of the vacuum evaporation system, and then the pressure in the chamber of the system was increased to 10 -6 The temperature was controlled at 500 K. Then, a current was passed through the cell to evaporate the introduced materials, 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 cell of the vacuum evaporation system and evaporated by passing a current through the cell, thereby forming a second hole injection layer with a thickness of 5 nm on the first hole injection layer. Next, compound HT-1 was introduced into another cell of the vacuum evaporation system and evaporated by passing a current through the cell, thereby forming a first hole transport layer with a thickness of 20 nm on the second hole injection layer. Next, compound HT-2 was introduced into another cell of the vacuum evaporation system and evaporated by passing a current through the cell, 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 hole transport layer, an emitting layer was formed thereon as follows: compound C-1 was introduced into one cell of the vacuum evaporation system as the host for the emitting layer, and compound BD was introduced into another cell as the dopant. 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 host and dopant to form a 20 nm-thick light-emitting layer on the second hole-transporting layer. Next, compounds ET-1 and EI-1 were evaporated in a 1:1 ratio in two other cells to deposit a 35 nm-thick electron-transporting layer on the light-emitting layer. Compound EI-1 was then deposited on the electron-transporting layer as a 2 nm-thick electron-injecting layer, and an 80 nm-thick Al cathode was then deposited on the electron-injecting layer using a separate vacuum deposition system. Thus, an OLED was fabricated.

[0059] As a result, the shortest time it took for the brightness at 2,000 nits to decrease from 100% to 95% was 76 hours.

[0060] Comparative Example 1: Fabrication of OLEDs containing conventional compounds An OLED was fabricated in the same manner as in Device Example 1, except that Compound H-1 was used as the host material in the light-emitting layer.

[0061] As a result, the shortest time it took for the brightness at 2,000 nits to decrease from 100% to 95% was 11 hours.

[0062] Comparative Example 2: Fabrication of OLEDs containing conventional compounds An OLED was fabricated in the same manner as in Device Example 1, except that Compound H-2 was used as the host material in the light-emitting layer.

[0063] As a result, the shortest time it took for the brightness at 2,000 nits to decrease from 100% to 95% was 25 hours.

[0064] Comparative Example 3: Fabrication of OLEDs containing conventional compounds An OLED was fabricated in the same manner as in Device Example 1, except that Compound H-3 was used as the host material in the light-emitting layer.

[0065] As a result, the shortest time it took for the brightness at 2,000 nits to decrease from 100% to 95% was 13 hours. [ka]

[0066] In the present disclosure, organic electroluminescent devices fabricated by substituting deuterium for hydrogen in the host compound in the light-emitting layer have been found to have significantly superior lifetime characteristics compared to organic electroluminescent devices using conventional compounds as hosts. This improvement in the lifetime characteristics of OLEDs is understood to be due to improved material stability resulting from the reduction in zero-point vibrational energy of the deuterated compound compared to undeuterated or deuterated compounds with fewer deuterium atoms. Furthermore, without intending to be limited by theory, controlling electron mobility is necessary to improve the lifetime of blue-emitting fluorescent organic electroluminescent devices, and dibenzofurans have faster hole mobility than aryls, so a similar effect to reducing electron mobility can be achieved. Without intending to be limited by theory, a reduction in electron mobility may reduce degradation of adjacent layers, thereby increasing lifetime. In terms of such effects, deuterizing a compound in which an anthracene is substituted with dibenzofuran may be advantageous compared to deuterizing a compound in which an anthracene is substituted with an aryl.

Claims

1. Formula 1 below: 【Chemistry 1】 (In the formula, R １ ~R ８ each independently represents hydrogen, but R ２ ~R ４ One of the 【Chemistry 2】 provided that it is bound to R ９ ~R １６ each independently represents hydrogen or deuterium; Ar １ represents deuterated or unsubstituted phenylnaphthyl or deuterated or unsubstituted naphthylphenyl; D Ｎ means that N hydrogen atoms are replaced with deuterium; N represents an integer of 8 to 30.

1. An organic electroluminescent compound represented by the formula:

2. Formula 1 is any one of the following formulas 1-1 to 1-3: 【Transformation 3】 (In the formula, R １ ~R ８ , R ９ ~R １６ , Ar １ , and D Ｎ is as defined in claim 1, N represents an integer of 8 to 30.

2. The organic electroluminescent compound of claim 1, represented by:

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

4. The compound of formula 1 is the following compound: 【Chemistry 4】 2. The organic electroluminescent compound of claim 1, selected from the group consisting of:

5. An organic electroluminescent material comprising the organic electroluminescent compound of claim 1.

6. An organic electroluminescent device comprising the organic electroluminescent compound of claim 1.

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

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