Organic electroluminescent compound and organic electroluminescent device comprising same

Abstract

The present application relates to an organic electroluminescent compound and an organic electroluminescent device comprising the same. The present disclosure relates to an organic electroluminescent compound and an organic electroluminescent device comprising the same. The organic electroluminescent compound of the present disclosure may be included in a light-emitting layer, and is effective for producing an organic electroluminescent device having high luminous efficiency and / or excellent lifespan characteristics.

Description

Technical Field

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

[0002] Electroluminescent (EL) devices are self-luminous devices, which have the advantages of providing wider viewing angles, greater contrast ratios, and faster response times. Organic EL devices were first developed by Eastman Kodak in 1987 by using small aromatic diamine molecules and aluminum complexes as materials for forming the light-emitting layer [Appl. Phys. Lett. [Applied Physics Letters] 51, 913, 1987].

[0003] Organic electroluminescent devices (OLEDs) convert electrical energy into light by applying power to organic light-emitting materials, and generally include an anode, a cathode, and an organic layer formed between the two electrodes. The organic layer of an OLED may include a hole injection layer, a hole transport layer, a hole auxiliary layer, a luminescent auxiliary layer, an electron blocking layer, a luminescent layer (containing a host and a dopant material), an electron buffer layer, a hole blocking layer, an electron transport layer, an electron injection layer, and the like. The materials used in the organic layer may be divided into hole injection materials, hole transport materials, hole auxiliary materials, luminescent auxiliary materials, electron blocking materials, luminescent materials, electron buffer materials, hole blocking materials, electron transport materials, electron injection materials, and the like according to their functions. In an OLED, due to the application of voltage, holes are injected from the anode into the luminescent layer, electrons are injected from the cathode into the luminescent 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 is emitted by emitting light from the energy of the organic light-emitting compound due to the excited state returning to the ground state.

[0004] Recently, according to the larger area of ​​the display, a luminescent material that can show more exquisite and vivid colors is required. Specifically, in the case of a material emitting 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, these materials are difficult to obtain a deep blue color with high color purity, and are problematic because they have a shorter luminescence life 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 having an energy level matching that of a material emitting blue light.

[0006] U.S. Patent No. 8,759,818 and U.S. Patent Application Publication No. 2014 / 0001459 disclose organic electroluminescent compounds containing anthracene moieties, wherein some hydrogen atoms are substituted by deuterium. However, these references do not specifically disclose organic electroluminescent compounds containing anthracene moieties, wherein some hydrogen atoms are substituted by deuterium, and wherein dibenzofuran is substituted at a certain position. Summary of the invention

[0007] Technical issues

[0008] The objects of the present disclosure are first to provide an organic electroluminescent compound which is effective for producing an organic electroluminescent device having excellent lifespan characteristics; and second to provide an organic electroluminescent device including the organic electroluminescent compound.

[0009] Solution to the problem

[0010] In organic electroluminescent devices, it is important to improve the blue light emitting material or the blue light emitting device. However, since the time when the organic electroluminescent device was developed, there has been no change in using a compound having a major portion of anthracene as a blue host material. Therefore, there are limitations in improving the life characteristics of the blue light emitting material or the blue light emitting device. In order to improve the life characteristics, the stability of the anthracene compound contained in the blue host material can be increased. One of the methods is deuteration. When the anthracene compound is deuterated, 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 have found that when an organic electroluminescent compound having a specific structure of Formula 1 is deuterated, a more significant improvement in lifespan is produced compared to anthracene compounds having other structures. By bonding a heteroaryl group rather than an aryl group to an anthracene nucleus, the mobility of holes and / or electrons can be improved, thereby reducing the driving voltage.

[0011]

[0012] in

[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, with the proviso that one of R2 to R4 is bonded to

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

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

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

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

[0018] Beneficial effects of the present invention

[0019] By using the organic electroluminescent compound according to the present disclosure, an organic electroluminescent device having an improved lifetime of emitted blue light can be produced. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a graph showing the 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 is not intended 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 contained in any layer constituting the organic electroluminescent device as 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 contain at least one compound. If necessary, the organic electroluminescent material can be contained 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 auxiliary material, a luminescence auxiliary material, an electron blocking material, a luminescent material, an electron buffer material, a hole blocking material, an electron transport material, an electron injection material, etc.

[0024] 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 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 may be included as a host such as a host for emitting blue light. According to one embodiment of the present disclosure, the compound having Formula 1 may be a fluorescent host, such as a fluorescent host for emitting blue light.

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

[0026] Herein, the term "(C1-C30) alkyl" means a straight or branched alkyl group having 1 to 30 carbon atoms constituting the chain, wherein the number of carbon atoms is preferably 1 to 20, and more preferably 1 to 10. The above-mentioned alkyl group may include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, and the like. The term "(C2-C30) alkenyl" means a straight or branched alkenyl group having 2 to 30 carbon atoms constituting the chain, wherein the number of carbon atoms is preferably 2 to 20, and more preferably 2 to 10. The above-mentioned alkenyl group may include vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-methylbut-2-enyl, and the like. The term "(C2-C30) alkynyl" means a straight or branched alkynyl group having 2 to 30 carbon atoms constituting the chain, wherein the number of carbon atoms is preferably 2 to 20, and more preferably 2 to 10. The above-mentioned alkynyl group 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 ring skeleton carbon atoms, wherein the number of carbon atoms is preferably 3 to 20, and more preferably 3 to 7. The above-mentioned cycloalkyl group 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, the heteroatom being selected from the group consisting of B, N, O, S, Si and P, and preferably consisting of O, S and N. The above-mentioned heterocycloalkyl group may include tetrahydrofuran, pyrrolidine, tetrahydrothiophene (thiolan), tetrahydropyran, etc. The term "(C6-C30) aryl" means a monocyclic or condensed ring group derived from an aromatic hydrocarbon having 6 to 30 ring skeleton carbon atoms, wherein the number of ring skeleton carbon atoms is preferably 6 to 25, more preferably 6 to 18. The above-mentioned aryl can be partially saturated and can include a spiro structure. The above-mentioned aryl can include phenyl, biphenyl, terphenyl, naphthyl, binaphthyl, phenylnaphthyl, naphthylphenyl, phenylterphenyl, fluorenyl, phenylfluorenyl, benzofluorenyl, dibenzofluorenyl, phenanthrenyl, phenylphenanthrenyl, anthracenyl, indenyl, triphenylene, pyrenyl, naphthyl, perylene, chrysene, naphthacene, fluoranthenyl, spirobifluorenyl, azulenyl, etc.More specifically, the aryl group may include phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, benzanthryl, 1-phenanthrenyl, 2-phenanthrenyl, 3-phenanthrenyl, 4-phenanthrenyl, 9-phenanthrenyl, naphthacene, pyrenyl, 1-chrysene, 2-chrysene, 3-chrysene, 4-chrysene, 5-chrysene, 6-chrysene, benzo[c]phenanthrenyl, benzo[g]chrysene, 1-triacetyl ...1-triacetyl, 2-triacetyl, 3-triacetyl, 4-triacetyl, 5-triacetyl, 6-triacetyl, benzo[c]phenanthrenyl, 1-triacetyl, 1-triacetyl, 2-triacetyl, 3-triacetyl, 4-triacetyl, 5-triacetyl, 6-triacetyl, 1-triacetyl, 1-triacetyl, 2-triacetyl, 3-triacetyl, 4-triacetyl, 5-triacetyl, 6-triacetyl, 1-triacetyl, 1-triacetyl, 1-triacetyl, 1-triacetyl, 1-triacetyl, 1-triacetyl, 1-triacetyl, 1-triacetyl, 1-triacetyl, 1-triacetyl, 1 phenyl, 2-triphenylene, 3-triphenylene, 4-triphenylene, 1-fluorenyl, 2-fluorenyl, 3-fluorenyl, 4-fluorenyl, 9-fluorenyl, benzofluorenyl, dibenzofluorenyl, 2-biphenyl, 3-biphenyl, 4-biphenyl, o-terphenyl, m-terphenyl-4-yl, m-terphenyl-3-yl, m-terphenyl-2-yl, p-terphenyl-4-yl, p-terphenyl-3-yl, p-terphenyl-2-yl, terphenyl-2-yl, m-quadrenyl, 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-cumyl, m-cumyl, p-cumyl, 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, and the like.

[0027] Herein, the term "(3- to 30-membered) heteroaryl" refers to an aryl group 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 group may be a monocyclic ring, or a condensed ring condensed with at least one benzene ring; may be partially saturated; may be a heteroaryl group formed by connecting at least one heteroaryl group or an aryl group to a heteroaryl group via one or more single bonds; and may contain a spiro structure. The above heteroaryl groups may include monocyclic heteroaryl groups, such as furanyl, thienyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, triazinyl, tetrazinyl, triazolyl, tetrazolyl, furazanyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, etc., and condensed ring heteroaryl groups, such as benzofuranyl, benzothienyl, isobenzofuranyl, dibenzofuranyl, dibenzothienyl, benzonaphthofuranyl, benzonaphthofuranyl, Thienyl, benzimidazolyl, benzothiazolyl, naphthiazolyl, benzisothiazolyl, benzisoxazolyl, benzoxazolyl, isoindolyl, indolyl, benzindolyl, indazolyl, benzothiadiazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl, benzoquinazolinyl, quinoxalinyl, benzoquinoxalinyl, naphthyridinyl, carbazolyl, benzocarbazolyl, dibenzocarbazolyl, phenoxazinyl, phenothiazinyl, phenanthridinyl, benzodioxolyl, dihydroacridinyl and the like. More specifically, the heteroaryl group may include 1-pyrrolyl, 2-pyrrolyl, 3-pyrrolyl, pyrazinyl, 2-pyridyl, 2-pyrimidyl, 4-pyrimidyl, 5-pyrimidyl, 6-pyrimidyl, 1,2,3-triazine-4-yl, 1,2,4-triazine-3-yl, 1,3,5-triazine-2-yl, 1-imidazolyl, 2-imidazolyl, 1-pyrazolyl, 1-indolyl, 2 -indolyl, 3-indolyl, 5-indolyl, 6-indolyl, 7-indolyl, 8-indolyl, 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-imidazopyridinyl, 6-imidazopyridinyl, 7-imidazopyridinyl, 8-imidazopyridinyl, 3-pyridinyl, 4-pyridinyl, -indolyl, 6-indolyl, 7-indolyl, 1-isoindolyl, 2-isoindolyl, 3-isoindolyl, 4-isoindolyl, 5-isoindolyl, 6-isoindolyl, 7-isoindolyl, 2-furanyl, 3-furanyl, 2-benzofuranyl, 3-benzofuranyl, 4-benzofuranyl, 5-benzofuranyl, 6-benzofuranyl, 7-benzofuranyl, 1-isobenzofuranyl pyranyl, 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, 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, 5-phenanthridinyl, 6-phenanthridinyl, 7-phenanthridinyl, 8-phenanthridinyl, 9-phenanthridin ... -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, respectively. Ortho means 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 means 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 means 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] In this article, the expression "substituted or unsubstituted" means that the 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; (3- to 30-membered)heteroaryl which is unsubstituted or substituted with one or more (C6-C30)aryl groups; (C6-C30)alkylthio which is unsubstituted or substituted with at least one of (C1-C30)alkyl and (3- to 30-membered)heteroaryl groups; )aryl; 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)arylborylcarbonyl; di(C1-C30)alkylborylcarbonyl; (C1-C30)alkyl(C6-C30)arylborylcarbonyl; (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 are each independently at least one selected from the group consisting of: methyl, phenyl, naphthyl, biphenyl and carbazolyl.

[0030] The compound represented by Formula 1 may be represented by any one of the following Formulas 1-1 to 1-3:

[0031]

[0032] in

[0033] R1 to R8, R9 to R 16 , Ar1, and D N is defined as in Equation 1, and

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

[0035] In Formula 1, 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- to 30-membered) heteroaryl, 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- 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- 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- to 15-membered) heteroaryl group; or an unsubstituted (5- to 20-membered) heteroaryl group substituted with one or more (C6-C12)aryl groups. Specifically, Ar1 can represent phenyl, naphthyl, biphenyl, terphenyl, phenanthryl, naphthylphenyl, phenylnaphthyl, binaphthyl, biphenylnaphthyl, dimethylfluorenyl, dimethylbenzofluorenyl, carbazolylphenyl, carbazolylnaphthyl, phenylbenzothiazolyl, phenylbenzoxazolyl, dibenzothienyl, phenylcarbazolyl, phenylnaphthothiazolyl, benzonaphthofuranyl, phenylbenzocarbazolyl, 19-membered nitrogen-containing heteroaryl, etc.

[0037] In formula 1, D N It means that N hydrogen atoms in Formula 1 are replaced by 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 deuterated at the number below the limit or higher, the increase in bond dissociation energy according to deuteration is sufficient to provide a significant increase in life characteristics. The upper limit is determined according to the number of hydrogen atoms that can be replaced in each compound.

[0038] In one embodiment of the present disclosure, in Formula 1, R1 to R8 of the present invention each independently represent hydrogen or deuterium; and Ar1 represents a substituted or unsubstituted (C6-C25)aryl group, or a substituted or unsubstituted (5- to 20-membered) heteroaryl group.

[0039] In another embodiment of the present disclosure, in Formula 1, R1 to R8 each independently represent hydrogen or deuterium; and Ar1 represents a (C6-C25)aryl group which is unsubstituted or substituted by at least one of a (C1-C6)alkyl group, a (C6-C15)aryl group and a (5- to 15-membered)heteroaryl group; or a (5- to 20-membered)heteroaryl group which is unsubstituted or substituted by one or more (C6-C12)aryl groups.

[0040] In the formula 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 skeleton atoms may be 5 to 20. According to another embodiment of the present disclosure, the number of ring skeleton 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 formula 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 tri(C1-C30) alkylsilyl, substituted or unsubstituted di(C1-C30) alkylsilyl, 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.

[0042] The compound represented by Formula 1 includes the following compounds, but is not limited thereto.

[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 scheme, 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 is as defined in Formula 1, and Hal represents a halogen.

[0053] 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 similar methods using deuterated precursor materials, or more generally, by treating non-deuterated compounds with deuterated solvents D6-benzene, etc. in the presence of Lewis acids such as aluminum chloride or ethylaluminum 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 reaction temperature and time, acid equivalents, etc., the number of N in Formula 1 can be controlled.

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

[0055] The present disclosure provides an organic electroluminescent material including an organic electroluminescent compound represented by Formula 1, and an organic electroluminescent device including the organic electroluminescent material. The material may consist only of the organic electroluminescent compound according to the present disclosure, or may further include 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 include 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 include a light-emitting layer, and may further include at least one layer selected from a hole injection layer, a hole transport layer, a hole auxiliary layer, a light-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.

[0058] The second electrode may be a transflective electrode or a reflective electrode, and the organic electroluminescent device may be a top emission type, a bottom emission type, or a double-sided emission type according to the kind of material formed.

[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 emission type, a bottom emission type, or a two-side emission 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 auxiliary layer, a light-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, 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 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 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 a 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 an arylamine-based compound and a styrylarylamine-based compound.

[0063] In addition, in the organic electroluminescent device of the present invention, the organic layer may further contain 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 Period 4, transition metals of Period 5, lanthanide elements and organic metals of d-transition elements, or at least one complex compound containing the metal.

[0064] In addition to the organic electroluminescent compound of the present invention, the organic electroluminescent device of the present invention can emit white light by further comprising 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 can further include a layer that emits yellow light or orange light.

[0065] 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, "surface layer") may be preferably placed on one or more inner surfaces of one or both electrodes. Specifically, a chalcogenide (including oxide) layer of silicon or aluminum is preferably placed on the anode surface of the electroluminescent medium layer, and a metal halide layer or a metal oxide layer is preferably placed on the cathode surface of the electroluminescent medium layer. The surface layer can provide operational stability for the organic electroluminescent device. Preferably, the chalcogenide comprises 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.; and metal oxides include 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 may be used between the anode and the light emitting layer. The hole injection layer may be a multilayer in order to reduce the hole injection barrier (or hole injection voltage) from the anode to the hole transport layer or the electron blocking layer, wherein each of the multilayers may use two compounds simultaneously. The hole transport layer or the electron blocking layer may also be a multilayer.

[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 a multilayer to control the injection of electrons and improve the interface characteristics between the light-emitting layer and the electron injection layer, wherein each of the multilayers may use two compounds at the same time. The hole blocking layer or the electron transport layer may also be a multilayer, wherein each of the multilayers may use a plurality of compounds.

[0068] The luminescent auxiliary layer can be placed between the anode and the luminescent layer, or between the cathode and the luminescent layer. When the luminescent auxiliary layer is placed between the anode and the luminescent layer, it can be used to promote hole injection and / or hole transport, or to prevent electron overflow. When the luminescent auxiliary layer is placed between the cathode and the luminescent 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 placed between the hole transport layer (or hole injection layer) and the luminescent layer, and the hole transport rate (or hole injection rate) can be effectively promoted or limited, so that the charge balance can be controlled. In addition, the electron blocking layer can be placed between the hole transport layer (or hole injection layer) and the luminescent layer, and the overflow electrons from the luminescent layer can be blocked and the excitons can be confined in the luminescent layer to prevent light leakage. When the organic electroluminescent device includes two or more hole transport layers, the hole transport layer further included can be used as a hole auxiliary layer or an electron blocking layer. The hole auxiliary layer and the electron blocking layer can have the effect of improving the efficiency and / or life of the organic electroluminescent device.

[0069] In the organic electroluminescent device of the present disclosure, it is preferred to place 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 on at least one surface of a pair of electrodes. In this case, the electron transport compound is reduced to anions, and thus it becomes easier to inject and transport electrons from the mixed region to the electroluminescent medium. In addition, the hole transport compound is oxidized to cations, and thus it becomes easier to inject and transport holes from the mixed region to 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. The reductive dopant layer can be used as a charge generation layer to prepare 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 light-emitting material for a white organic light-emitting device. According to the arrangement of R (red), G (green), B (blue), or YG (yellow-green) light-emitting units, white organic light-emitting devices with 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 containing QD (quantum dots).

[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 a wet film-forming method is used, a thin film can be formed by dissolving or diffusing a material 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 forming each layer is soluble or dispersible in the solvent, which does not cause any problem in forming a film.

[0073] A display system, such as a display system for a smartphone, a tablet computer, a notebook computer, a PC, a TV, or a car; 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 compound of the present disclosure, the characteristics of the compound, and the luminescent characteristics of the organic electroluminescent device including the compound will be described in detail with reference to the representative compound 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] 3.5g of compound 1 (8.3mmol) and 100mL of benzene-D6 are introduced into a flask, and heated to dissolve all of compound 1. After the mixture is cooled to room temperature, 4.4mL of trifluoromethanesulfonic acid (49.8mmol) is added thereto. After the mixture is stirred at room temperature for 2 hours and 30 minutes, 20mL of heavy water is added thereto. After stirring for 10 minutes, the mixture is neutralized with a K3PO4 aqueous solution. The organic layer is extracted with dichloromethane, and magnesium sulfate is used to remove the remaining moisture. The obtained organic layer is distilled under reduced pressure and separated by column chromatography to obtain 1.5g of compound C-1 (yield: 41.3%). The number of deuterium substituted is observed with molecular weight and NMR.

[0078] MW MP 437.61 279.2℃

[0079] Device Example 1: Production of OLEDs Comprising Compounds According to the Disclosure

[0080] An OLED containing an organic electroluminescent compound according to the present disclosure was produced as follows: A transparent electrode indium tin oxide (ITO) thin film (10Ω / sq) on a glass substrate for OLED (GEOMATEC CO., LTD., Japan) was subjected to ultrasonic washing with acetone, ethanol, and distilled water in sequence, and then stored in isopropanol. The ITO substrate was mounted on a substrate holder of a vacuum vapor deposition apparatus. Compound HI-1 was introduced into a chamber of the vacuum vapor deposition apparatus, and then the pressure in the chamber of the apparatus was controlled to 10 -6 Tolerance. Thereafter, an electric current is applied to the chamber to evaporate the above introduced materials, thereby forming a first hole injection layer with a thickness of 60nm on the ITO substrate. Next, compound HI-2 is introduced into another chamber of a vacuum vapor deposition device, and the compound is evaporated by applying an electric current to the chamber, thereby forming a second hole injection layer with a thickness of 5nm on the first hole injection layer. Compound HT-1 is then introduced into another chamber of a vacuum vapor deposition device, and the compound is evaporated by applying an electric current to the chamber, thereby forming a first hole transport layer with a thickness of 20nm on the second hole injection layer. Compound HT-2 is then introduced into another chamber of a vacuum vapor deposition device, and the compound is evaporated by applying an electric current to the chamber, thereby forming a second hole transport layer with a thickness of 5nm on the first hole transport layer. After the hole injection layer and the hole transport layer are formed, a light-emitting layer is formed thereon as follows: Compound C-1 is introduced into a chamber of a vacuum vapor deposition device as the main body of the light-emitting layer, and compound BD is introduced into another chamber as a dopant. The two materials were evaporated at different rates and the dopant was deposited at a doping amount of 2wt% based on the total amount of the host and the dopant to form a light-emitting layer with a thickness of 20nm 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 35nm on the light-emitting layer. After compound EI-1 was deposited as an electron injection layer with a thickness of 2nm on the electron transport layer, an Al cathode with a thickness of 80nm was deposited on the electron injection layer by another vacuum vapor deposition device. In this way, an OLED was produced.

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

[0082] Comparative Example 1: Production of OLEDs containing conventional compounds

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

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

[0085] Comparative Example 2: Production of OLEDs containing conventional compounds

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

[0087] As a result, the minimum time required to reduce the brightness from 100% to 95% at 2,000 nits was 25 hours.

[0088] Comparative Example 3: Production of OLEDs containing conventional compounds

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

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

[0091]

[0092] In the present disclosure, an organic electroluminescent device is produced by replacing the hydrogen of the host compound of the light-emitting layer with deuterium, and it can be seen that the life characteristics are far superior to the organic electroluminescent device using conventional compounds as the host. It should be understood that this improvement in the life characteristics of OLEDs is due to the improvement of material stability compared to compounds that are not deuterated or deuterated with less deuterium, and the improvement in stability is due to the reduction of the zero-point vibration energy of the deuterated compound. In addition, it is not intended to be limited by theory. In order to improve the life 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 an aryl group, a similar effect of reducing electron mobility can be obtained. It is not intended to be limited by theory, and the reduction in electron mobility can lead to a reduction in the degradation of adjacent layers, thereby increasing the life span. In terms of this effect, it may be advantageous to deuterate a compound in which anthracene is replaced by an aryl group compared to a compound in which anthracene is replaced by a deuterated compound.

Claims

1. An organic electroluminescent compound, which is represented by the following formula 1: in R1 to R4 each independently represent hydrogen or deuterium, provided that one of R2 to R4 is bonded to R5 to R8 each independently represent hydrogen, deuterium, deuterium-substituted or unsubstituted (C6-C30)aryl, or deuterium-substituted or unsubstituted (5-membered to 30-membered)heteroaryl, provided that at least one of R5 to R8 is deuterium-substituted or unsubstituted (C6-C30)aryl or deuterium-substituted or unsubstituted (5-membered to 30-membered)heteroaryl; R9 to R 16 each independently represents hydrogen or deuterium; Ar1 represents a deuterium-substituted or unsubstituted (C6-C30) aryl group, or a deuterium-substituted or unsubstituted (5- to 30-membered) heteroaryl group; D N means that N hydrogen atoms are replaced by deuterium; and N represents an integer of 8 to 50.

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: in R1 to R 16 , Ar1, and D N is as defined in claim 1; and N represents an integer of 8 to 30.

3. The organic electroluminescent compound according to claim 1, wherein Ar1 represents a deuterium-substituted or unsubstituted (C6-C25) aryl group, or a deuterium-substituted or unsubstituted (5- to 20-membered) heteroaryl group.

4. The organic electroluminescent compound according to claim 1, wherein Ar1 represents deuterium-substituted or unsubstituted phenyl, deuterium-substituted or unsubstituted naphthyl, deuterium-substituted or unsubstituted biphenyl, deuterium-substituted or unsubstituted terphenyl, deuterium-substituted or unsubstituted phenanthryl, deuterium-substituted or unsubstituted naphthylphenyl, deuterium-substituted or unsubstituted phenylnaphthyl, deuterium-substituted or unsubstituted binaphthyl, deuterium-substituted or unsubstituted biphenylnaphthyl, deuterium-substituted or unsubstituted dimethylfluorenyl, deuterium-substituted or unsubstituted dimethylbenzofluorenyl, deuterium-substituted or unsubstituted dibenzothiophenyl, or deuterium-substituted or unsubstituted benzonaphthofuranyl.

5. The organic electroluminescent compound according to claim 1, wherein N represents an integer of 8 to 30.

6. The organic electroluminescent compound according to claim 1, wherein R6 to R8 each independently represent hydrogen or deuterium, and R5 represents a deuterium-substituted or unsubstituted (C6-C30)aryl group, or a deuterium-substituted or unsubstituted (5- to 30-membered) heteroaryl group.

7. The organic electroluminescent compound according to claim 1, wherein R5, R7 and R8 each independently represent hydrogen or deuterium; and R6 represents a deuterium-substituted or unsubstituted (C6-C30)aryl group, or a deuterium-substituted or unsubstituted (5- to 30-membered) heteroaryl group.

8. The organic electroluminescent compound according to claim 1, wherein R5, R6 and R8 each independently represent hydrogen or deuterium; and R7 represents a deuterium-substituted or unsubstituted (C6-C30)aryl group or a deuterium-substituted or unsubstituted (5- to 30-membered) heteroaryl group.

9. The organic electroluminescent compound according to claim 1, wherein R6 to R8 each independently represent hydrogen or deuterium; and R5 represents deuterium-substituted or unsubstituted phenyl, deuterium-substituted or unsubstituted naphthyl, deuterium-substituted or unsubstituted biphenyl, deuterium-substituted or unsubstituted terphenyl, deuterium-substituted or unsubstituted phenanthryl, deuterium-substituted or unsubstituted naphthylphenyl, deuterium-substituted or unsubstituted phenylnaphthyl, deuterium-substituted or unsubstituted binaphthyl, deuterium-substituted or unsubstituted biphenylnaphthyl, deuterium-substituted or unsubstituted dimethylfluorenyl, deuterium-substituted or unsubstituted dimethylbenzofluorenyl, deuterium-substituted or unsubstituted dibenzothiophenyl, or deuterium-substituted or unsubstituted benzonaphthofuranyl.

10. The organic electroluminescent compound according to claim 1, wherein R5, R7 and R8 each independently represent hydrogen or deuterium; and R6 represents deuterium-substituted or unsubstituted phenyl, deuterium-substituted or unsubstituted naphthyl, deuterium-substituted or unsubstituted biphenyl, deuterium-substituted or unsubstituted terphenyl, deuterium-substituted or unsubstituted phenanthryl, deuterium-substituted or unsubstituted naphthylphenyl, deuterium-substituted or unsubstituted phenylnaphthyl, deuterium-substituted or unsubstituted binaphthyl, deuterium-substituted or unsubstituted biphenylnaphthyl, deuterium-substituted or unsubstituted dimethylfluorenyl, deuterium-substituted or unsubstituted dimethylbenzofluorenyl, deuterium-substituted or unsubstituted dibenzothiophenyl, or deuterium-substituted or unsubstituted benzonaphthofuranyl.

11. The organic electroluminescent compound according to claim 1, wherein R5, R6 and R8 each independently represent hydrogen or deuterium; and R7 represents deuterium-substituted phenyl, deuterium-substituted naphthyl, deuterium-substituted biphenyl, deuterium-substituted terphenyl, deuterium-substituted phenanthryl, deuterium-substituted naphthylphenyl, deuterium-substituted phenylnaphthyl, deuterium-substituted binaphthyl, deuterium-substituted biphenylnaphthyl, deuterium-substituted dimethylfluorenyl, deuterium-substituted dimethylbenzofluorenyl, deuterium-substituted or unsubstituted dibenzothiophenyl, or deuterium-substituted or unsubstituted benzonaphthofuranyl. 12 . An organic electroluminescent material comprising the organic electroluminescent compound according to claim 1 .

13. The organic electroluminescent material according to claim 12, wherein: The organic electroluminescent compound as claimed in claim 1 is contained as a first host material, and a compound other than the organic electroluminescent compound as claimed in claim 1 is further contained as a second host material.

14. An organic electroluminescent device comprising the organic electroluminescent compound according to claim 1.

15. The organic electroluminescent device according to claim 14, wherein: The organic electroluminescent compound is contained in the light emitting layer.

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