Organic electroluminescent compound and organic electroluminescent device comprising the same

Abstract

The present disclosure relates to an organic electroluminescent compound and an organic electroluminescent device including the same. By including the organic electroluminescent compound, an organic electroluminescent device having a low driving voltage and / or high luminous efficiency and / or long lifespan can be provided.

Description

Technical Field

[0001] This disclosure relates to an organic electroluminescent compound and an organic electroluminescent device comprising the same. Background Technology

[0002] Electroluminescent devices (EL devices) are self-emissive display devices that offer advantages such as a wider viewing angle, a higher contrast ratio, and a faster response time. The first organic EL device was developed by Eastman Kodak in 1987 using small aromatic diamine molecules and aluminum complexes as materials for forming the luminescent layer [Appl. Phys. Lett. 51, 913, 1987].

[0003] Organic light-emitting diode (OLED) devices convert electrical energy into light by applying electricity to organic electroluminescent materials, and typically include an anode, a cathode, and an organic layer formed between these two electrodes. The organic layer of an OLED device may include a hole injection layer, a hole transport layer, a hole auxiliary layer, a light-emitting auxiliary layer, an electron blocking layer, a light-emitting layer (containing a host material and dopant materials), an electron buffer layer, a hole blocking layer, an electron transport layer, and an electron injection layer, etc. In such organic OLED devices, holes from the anode and electrons from the cathode are injected into the light-emitting layer by applying a voltage, and high-energy excitons are generated through the recombination of holes and electrons. The organic light-emitting compound moves to an excited state by energy and emits light by the energy when the organic light-emitting compound returns from the excited state to the ground state.

[0004] In conventional technologies, 4,4'-N,N'-dicarbazole-biphenyl (CBP) is the most well-known phosphorescent host material. While conventional phosphorescent host materials offer good luminescence characteristics, they have the following disadvantages: (1) Due to their low glass transition temperature and poor thermal stability, they may degrade during high-temperature deposition processes in a vacuum, potentially shortening the device's lifespan. (2) The power efficiency of organic electroluminescent devices is derived from [(π / voltage) × current efficiency], and power efficiency is inversely proportional to voltage. Although organic electroluminescent devices containing phosphorescent host materials offer higher current efficiency (cd / A) than those containing fluorescent materials, they require considerably higher driving voltages. Therefore, there is no advantage in terms of power efficiency (1m / W). (3) Furthermore, organic electroluminescent devices have short operating lifetimes and still require improvements in luminescence efficiency. Therefore, to achieve superior characteristics in organic EL devices, the materials constituting the organic layer in the device, especially the host or dopant constituting the luminescent material, should be appropriately selected.

[0005] Korean Patent No. 2014-0006708 A discloses an organic electroluminescent device that uses the following compound as a green phosphorescent host material, wherein pyridine, pyrimidine or triazine is linked to an indolecarbazole derivative using at least one naphthyl group as a linking group.

[0006] Korean Patent Nos. 2013-0057397 A and 2016-0131963 A disclose heterocyclic compounds that can be used as host materials for luminescent layers; however, they do not disclose host compounds having indole-carbazole derivatives as the basic framework. Summary of the Invention

[0007] Technical issues

[0008] The purpose of this disclosure is firstly to provide an organic electroluminescent compound capable of producing an organic electroluminescent device having a low driving voltage and / or high luminous efficiency and / or long lifetime, and secondly to provide an organic electroluminescent device comprising the organic electroluminescent compound.

[0009] Solution to the problem

[0010] As a result of in-depth research to solve the aforementioned technical problems, the inventors of this invention discovered that the aforementioned objective can be achieved by an organic electroluminescent compound represented by Formula 1, thereby completing this invention.

[0011]

[0012] In Equation 1,

[0013] Ring A is a ring with three or more rings;

[0014] Ar1 and Ar2 each independently represent hydrogen, deuterium, cyano, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (3- to 30-membered) heteroaryl, or substituted or unsubstituted (C3-C30) cycloalkyl.

[0015] L1 and L2 each independently represent a single bond, a substituted or unsubstituted (C1-C30) alkylene, a substituted or unsubstituted (C6-C30) arylene, a substituted or unsubstituted (3- to 30-membered) heteroarylene, or a substituted or unsubstituted (C3-C30) cycloalkylene.

[0016] R1 to R3 independently represent hydrogen, deuterium, halogen, cyano, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (3- 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) alkyl(C6-C30) aryl alkylsilyl, 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, or substituted or unsubstituted (C1-C30)alkyl(C6-C30)arylamino; or may be linked with adjacent substituents to form substituted or unsubstituted rings;

[0017] a represents an integer from 1 to 4;

[0018] b represents an integer of 1 or greater;

[0019] c represents an integer of 1 or 2; and

[0020] When a to c are 2 or greater, each R1, each R2, or each R3 can be the same or different.

[0021] Beneficial effects of the present invention

[0022] By using the organic electroluminescent compound according to the present disclosure, organic electroluminescent devices with low driving voltage and / or high luminous efficiency and / or long lifetime can be prepared. Detailed Implementation

[0023] This disclosure will now be described in detail. However, the following description is intended to explain the invention and is not intended to limit the scope of the invention in any way.

[0024] This disclosure relates to an organic electroluminescent compound represented by Formula 1 and an organic electroluminescent device comprising said organic electroluminescent compound.

[0025] The term "organic electroluminescent compound" in this disclosure means a compound that can be used in an organic electroluminescent device and, if necessary, can be included in any material layer constituting the organic electroluminescent device.

[0026] The term "organic electroluminescent material" in this disclosure refers to a material that can be used in an organic electroluminescent device and may contain at least one compound. If desired, the organic electroluminescent material may be contained in any layer constituting the organic electroluminescent device. For example, the organic electroluminescent material may be a hole injection material, a hole transport material, a hole assist material, a light-emitting assist material, an electron blocking material, a light-emitting material, an electron buffer material, a hole blocking material, an electron transport material, or an electron injection material, etc.

[0027] In this document, "(C1-C30)alkylene" refers to a straight-chain 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 aforementioned alkyl group may include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, etc. "(C3-C30)cycloalkylene" is a monocyclic or polycyclic hydrocarbon having 3 to 30 carbon atoms in the ring skeleton, wherein the number of carbon atoms is preferably 3 to 20, and more preferably 3 to 7. The aforementioned cycloalkyl group may include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc. "(C6-C30)aryl" is a monocyclic or fused-ring group derived from an aromatic hydrocarbon having 6 to 30 carbon atoms in the ring skeleton, wherein the number of carbon atoms in the ring skeleton is preferably 6 to 20, more preferably 6 to 15, and may be partially saturated and may contain a spirostructure. Specific examples of aryl groups include phenyl, biphenyl, terphenyl, tetraphenyl, naphthyl, binatyl, phenylnaphthyl, naphthylphenyl, fluorenyl, phenylfluorenyl, dimethylfluorenyl, diphenylfluorenyl, benzo[a]fluorenyl, diphenylbenzo[a]fluorenyl, dibenzo[a]fluorenyl, phenanthrene, benzo[a]phenanthrene, phenylphenanthrene, anthracene, benzo[a]anthrene, indene, triphenylene, pyrene, tetraphenyl, perylene, etc. Benzyl, benzo[ Aryl, naphthyl, fluoranthyl, benzofluoranthyl, tolyl, xylyl, mesitylene, isopropylphenyl, spiro[fluorene-fluorene]yl, spiro[fluorene-benzofluorene]yl, azulene, etc. More specifically, aryl can be o-tolyl, m-tolyl, p-tolyl, 2,3-xylyl, 3,4-xylyl, 2,5-xylyl, mesitylene, o-isopropylphenyl, m-isopropylphenyl, p-isopropylphenyl, p-tert-butylphenyl, p-(2-phenylpropyl)phenyl, 4′-methylbiphenyl, 4″-tert-butyl-p-terphenyl-4-yl, o-biphenyl, m-biphenyl, p-biphenyl, o-terphenyl, m-terphenyl-4-yl, m-terphenyl-3-yl, m-terphenyl-2-yl, p-terphenyl-4-yl, p-terphenyl-3 ... Triphenyl-2-yl, meta-tetraphenyl, 1-naphthyl, 2-naphthyl, 1-fluorenyl, 2-fluorenyl, 3-fluorenyl, 4-fluorenyl, 9-fluorenyl, 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, 1-anthrayl, 2-anthrayl, 9-anthrayl, 1-phenanthyl, 2-phenanthyl, 3-phenanthyl, 4-phenanthyl, 9-phenanthyl, 1- basal, 2- basal, 3- basal, 4- Base, 5- Base, 6- Benzyl, benzo[c]phenanthrene, benzo[g] The terms include 1-triphenylene, 2-triphenylene, 3-triphenylene, 4-triphenylene, 3-fluoranthryl, 4-fluoranthryl, 8-fluoranthryl, 9-fluoranthryl, benzofluoranthryl, etc. "(3- to 30-membered) heteroaryl" refers to an aryl group having 3 to 30 ring skeleton atoms, preferably 5 to 25, including at least one, preferably 1 to 4, heteroatoms selected from the group consisting of B, N, O, S, Si, P, and Ge. The aforementioned heteroaryl groups can be monocyclic or fused rings condensed with at least one benzene ring; and can be partially saturated. The aforementioned heteroatom may be attached to at least one substituent 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 dialkylsilyl, etc. (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(C6-30)arylamino. Furthermore, the above heteroaryl groups can be heteroaryl groups formed by attaching at least one heteroaryl group or aryl group to a heteroaryl group via one or more single bonds; and can contain a spirostructure. Examples of heteroaryl groups specifically include monocyclic heteroaryl groups, including furanyl, thiopheneyl, pyrroleyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, triazinyl, tetraazinyl, triazolyl, tetraazolyl, furazonyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, etc., as well as fused-ring heteroaryl groups, including benzofuranyl, benzothiopheneyl, isobenzofuranyl, dibenzofuranyl, dibenzothiopheneyl, benzimidazolyl, benzothiazolyl, benzoisothiazolyl, and benziisothiazolyl. Oxazolyl, benzoxazolyl, imidazopyridyl, isoindolyl, indolyl, benzoindolyl, indazole, benzothiadiazolyl, quinolinyl, isoquinolinyl, cenolinyl, quinazolinyl, quinoxalinyl, carbazole, azacarbazole, benzocarbazole, dibenzocarbazole, phenoxazinyl, phenanthidyl, benzodioxanepentenyl, indolizidyl, acrylidine, silafluorenyl, germaniumfluorenyl, etc. More specifically, heteroaryl groups can be 1-pyrroleyl, 2-pyrroleyl, 3-pyrroleyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, 2-pyrimidinyl, 4-pyrimidinyl, 5-pyrimidinyl, 6-pyrimidinyl, 1,2,3-triazin-4-yl,1,2,4-Triazine-3-yl, 1,3,5-Triazine-2-yl, 1-Imidazolyl, 2-Imidazolyl, 1-Pyrazolyl, 1-Indorazidinyl, 2-Indorazidinyl, 3-Indorazidinyl, 5-Indorazidinyl, 6-Indorazidinyl, 7-Indorazidinyl, 8-Indorazidinyl, 2-Imidazolopyridyl, 3-Imidazolopyridyl 5-Imidazolopyridyl, 6-Imidazolopyridyl, 7-Imidazolopyridyl, 8-Imidazolopyridyl, 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 Doloyl, 2-furanyl, 3-furanyl, 2-benzofuranyl, 3-benzofuranyl, 4-benzofuranyl, 5-benzofuranyl, 6-benzofuranyl, 7-benzofuranyl, 1-isobenzofuranyl, 3-isobenzofuranyl, 4-isobenzofuranyl, 5-isobenzofuranyl, 6-isobenzofuranyl, 7-isobenzofuranyl, 2-quinolinyl, 3 -quinolinyl, 4-quinolinyl, 5-quinolinyl, 6-quinolinyl, 7-quinolinyl, 8-quinolinyl, 1-isoquinolinyl, 3-isoquinolinyl, 4-isoquinolinyl, 5-isoquinolinyl, 6-isoquinolinyl, 7-isoquinolinyl, 8-isoquinolinyl, 2-quinoxalyl, 5-quinoxalyl, 6-quinoxalyl, 1-carbazoleyl, 2-carbazoleyl, 3-carbazoleyl, 4- Carbazolyl, 9-carbazolyl, azacarbazo-1-yl, azacarbazo-2-yl, azacarbazo-3-yl, azacarbazo-4-yl, azacarbazo-5-yl, azacarbazo-6-yl, azacarbazo-7-yl, azacarbazo-8-yl, azacarbazo-9-yl, 1-phenanthridyl, 2-phenanthridyl, 3-phenanthridyl, 4-phenanthridyl, 6-phenanthridyl, 7-phenanthridyl Pyridyl, 8-phenanthridyl, 9-phenanthridyl, 10-phenanthridyl, 1-acridyl, 2-acridyl, 3-acridyl, 4-acridyl, 9-acridyl, 2-oxazolyl, 4-oxazolyl, 5-oxazolyl, 2-oxadiazolyl, 5-oxadiazolyl, 3-furazanyl, 2-thienyl, 3-thienyl, 2-methylpyrrole-1-yl, 2-methylpyrrole-3-yl, 2 1-Methylpyrrolo-4-yl, 2-methylpyrrolo-5-yl, 3-methylpyrrolo-1-yl, 3-methylpyrrolo-2-yl, 3-methylpyrrolo-4-yl, 3-methylpyrrolo-5-yl, 2-tert-butylpyrrolo-4-yl, 3-(2-phenylpropyl)pyrrolo-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-dibenzothiophenyl4-Dibenzothiopheneyl, 1-siliconyl, 2-siliconyl, 3-siliconyl, 4-siliconyl, 1-germanium fluorenyl, 2-germanium fluorenyl, 3-germanium fluorenyl, and 4-germanium fluorenyl, etc.

[0028] "Nitrogen-containing (5- to 30-membered) heteroaryl" refers to an aryl group having at least one nitrogen atom and 5 to 30 ring skeleton atoms, wherein the number of ring skeleton atoms is preferably 5 to 20, more preferably 5 to 15; preferably having 1 to 4 heteroatoms, and can be monocyclic or a fused ring condensed with at least one benzene ring; and can be partially saturated. Furthermore, the above-mentioned nitrogen-containing heteroaryl group can be a heteroaryl group formed by linking at least one heteroaryl group or aryl group to a heteroaryl group via one or more single bonds; and includes monocyclic heteroaryl groups, including pyrroloyl, imidazolyl, pyrazolyl, triazinyl, tetraazinyl, triazolyl, tetraazolyl, pyridinyl, pyrazinyl, pyrimidinyl, pyridazinyl, etc., and fused-ring heteroaryl groups, including benzimidazolyl, isoindolyl, indolyl, inazolyl, benzothiadiazolyl, quinolinyl, isoquinolinyl, borolinyl, quinazolinyl, quinoxalinyl, benzoquinoxalinyl, carbazole, phenanthridineyl, etc. Halogens include F, Cl, Br, and I.

[0029] Furthermore, "ortho (o)," "meta (m)," and "para (p)" indicate the substitution positions of all substituents. The ortho position is a compound with substituents adjacent to each other, such as at positions 1 and 2 on benzene. The meta position is the next substitution position after the immediately adjacent substitution position; for example, a compound with substituents at positions 1 and 3 on benzene. The para position is the next substitution position after the meta position; for example, a compound with substituents at positions 1 and 4 on benzene.

[0030] In this document, "substituted or unsubstituted ring formed by connection with adjacent substituents" refers to a substituted or unsubstituted (C3-C30) monocyclic or polycyclic alicyclic ring, aromatic ring, or combination thereof formed by connecting or fused two or more adjacent substituents; preferably, it can be a substituted or unsubstituted (C5-C25) monocyclic or polycyclic alicyclic ring, aromatic ring, or combination thereof; more preferably, it can be a substituted or unsubstituted (C5-C18) monocyclic or polycyclic alicyclic ring, aromatic ring, or combination thereof. Furthermore, at least one carbon atom in the formed ring can be replaced by at least one heteroatom selected from B, N, O, S, Si, and P, preferably from the group consisting of N, O, and S. According to one embodiment, the ring formed by connection with adjacent substituents can be a (C5-C20) polycyclic aromatic ring, which may contain at least one heteroatom selected from the group consisting of N, O, and S.

[0031] Furthermore, the term "substituted" in the expression "substituted or unsubstituted" means that a hydrogen atom in a functional group is replaced by another atom or functional group (i.e., a substituent). Substituted (C1-C30)alkylene, substituted (C6-C30)aryl, substituted (3- to 30-membered)heteroaryl, substituted (C3-C30)cycloalkylene, substituted (C1-C30)alkoxy, substituted tri(C1-C30)alkylsilyl, substituted di(C1-C30)alkyl(C6-C30)arylsilyl, substituted (C1-C30)alkyldi(C6-C30)arylsilyl, substituted tri(C6-C30)arylsilyl, substituted mono- or di-(C1-C30)arylsilyl, etc., are found in Ar1, Ar2, L1, L2, and R1 to R3. -C30)alkylamino, substituted mono- or di-(C6-C30)arylamino, substituted (C1-C30)alkyl(C6-C30)arylamino, and the substituents of the substituted ring are each independently selected from at least one of the following groups: deuterium, halogen, cyano, carboxyl, nitro, hydroxyl, (C1-C30)alkyl, halo(C1-C30)alkyl, (C2-C30)alkenyl, (C2-C30)alkoxy, (C1-C30)alkylthio, (C3-C30)cycloalkyl, (C3-C30)cycloalkenyl, (3- to 7-membered)heterocyclic alkyl, (C6-C30)alkylyl, (C6-C30)alkylyl, alkylyl ... aryloxy, (C6-C30)arylthio, (C6-C30)aryl-substituted or unsubstituted (3- to 30-membered) heteroaryl, (3- to 30-membered) heteroaryl-substituted or unsubstituted (C6-C30)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, (C1-C30)alkyl-substituted or unsubstituted mono- or di-(C6-C30)aryl Amino, (C1-C30)alkyl(C6-C30)arylamino, (C1-C30)alkylcarbonyl, (C1-C30)alkoxycarbonyl, (C6-C30)arylcarbonyl, di(C6-C30)arylboroncarbonyl, di(C1-C30)alkylboroncarbonyl, (C1-C30)alkyl(C6-C30)arylboroncarbonyl, (C6-C30)aryl(C1-C30)alkyl, and (C1-C30)alkyl(C6-C30)aryl, for example, the substituent may be unsubstituted phenyl, unsubstituted o-phenyl, unsubstituted meta-phenyl, unsubstituted para-phenyl, or unsubstituted naphthyl.

[0032] The organic electroluminescent compound according to one embodiment will be described below.

[0033] According to one embodiment, the organic electroluminescent compound is represented by the following formula 1.

[0034]

[0035] In Equation 1,

[0036] Ring A is a ring with three or more rings;

[0037] Ar1 and Ar2 each independently represent hydrogen, deuterium, cyano, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (3- to 30-membered) heteroaryl, or substituted or unsubstituted (C3-C30) cycloalkyl.

[0038] L1 and L2 each independently represent a single bond, a substituted or unsubstituted (C1-C30) alkylene, a substituted or unsubstituted (C6-C30) arylene, a substituted or unsubstituted (3- to 30-membered) heteroarylene, or a substituted or unsubstituted (C3-C30) cycloalkylene.

[0039] R1 to R3 independently represent hydrogen, deuterium, halogen, cyano, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (3- 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) alkyl(C6-C30) aryl alkylsilyl, 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, or substituted or unsubstituted (C1-C30)alkyl(C6-C30)arylamino; or may be linked with adjacent substituents to form substituted or unsubstituted rings;

[0040] a represents an integer from 1 to 4;

[0041] b represents an integer of 1 or greater;

[0042] c represents an integer of 1 or 2; and

[0043] When a to c are 2 or greater, each R1, each R2, or each R3 can be the same or different.

[0044] According to one embodiment, the organic electroluminescent compound having Formula 1 can be included as a host material in the light-emitting layer of the organic electroluminescent device.

[0045] According to one embodiment, an organic electroluminescent compound having Formula 1 has a basic skeleton in which an electron-withdrawing group (EWG) with high electron-withdrawing ability (such as aryl and / or nitrogen-containing heteroaryl) is bonded to an indobenzocarbazole derivative.

[0046] Generally, indolocarbazole can be formed into various structures depending on the bonding position of the carbazole moiety, and is suitable as a hole transport host due to its high HOMO (highest occupied molecular orbital) energy level. An organic electroluminescent compound having Formula 1 has the following structure, in which the nitrogen (N) of indolocarbazole is bonded in a specific direction, i.e., facing the same direction; and the basic skeleton is formed by the condensation of indolocarbazole with at least one benzene ring at its end; one or more nitrogen (N) atoms of indolocarbazole are bonded to aryl and / or nitrogen-containing heteroaryl groups with strong electronic signatures, thereby giving the entire molecule a bipolar characteristic. As a result, the binding force between holes and electrons can be increased, allowing the disclosed compound to exhibit excellent characteristics as a host material for the luminescent layer; and thus, an organic electroluminescent device with low driving voltage and / or high luminous efficiency and / or long lifetime can be provided.

[0047] Furthermore, the structure in which at least one benzene ring is partially condensed with indolocarbazole improves the thermal stability of the device by increasing the conjugation length while maintaining material properties, thereby improving the lifespan characteristics.

[0048] In one embodiment, in Formula 1, ring A is a tricyclic or multicyclic ring, for example, a tricyclic to pentacyclic ring. Preferably, ring A is a tricyclic or multicyclic aryl ring, more preferably a fused ring condensed with at least three benzene rings. For example, ring A can be a substituted or unsubstituted phenanthrene, or a substituted or unsubstituted benzo[a]naphthalene.

[0049] According to one embodiment, the organic electroluminescent compound can be represented by any one of the following formulas 1-1 to 1-3 as the basic framework, wherein at least one benzene ring is partially condensed with indolo[2,3-b]carbazole.

[0050]

[0051]

[0052] In equations 1-1 to 1-3, Ar1, Ar2, L1, L2, R1 to R3, a, and c are as defined in equation 1;

[0053] R4 and R5 independently represent hydrogen, deuterium, halogen, cyano, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (3- 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) alkyl(C6-C30) aryl. alkylsilyl, 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, or substituted or unsubstituted (C1-C30)alkyl(C6-C30)arylamino; or may be linked with adjacent substituents to form substituted or unsubstituted rings;

[0054] b represents an integer from 1 to 6;

[0055] d and e are each independently defined as a; and

[0056] When b, d, and e are integers of 2 or greater, each R2, each R4, or each R5 can be the same or different.

[0057] In one embodiment, in Formula 1 and 1-1 to 1-3, Ar1 and Ar2 each independently represent hydrogen, deuterium, cyano, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (3- to 30-membered) heteroaryl, or substituted or unsubstituted (C3-C30) cycloalkyl. Preferably, each can independently represent hydrogen, substituted or unsubstituted (C6-C18) aryl, or substituted or unsubstituted (3- to 18-membered) heteroaryl. More preferably, each can independently represent hydrogen, substituted or unsubstituted (C6-C12) aryl, or substituted or unsubstituted nitrogen-containing (5- to 20-membered) heteroaryl. For example, Ar1 and Ar2 can each independently be hydrogen, substituted or unsubstituted phenyl, substituted or unsubstituted o-phenyl, substituted or unsubstituted meta-phenyl, substituted or unsubstituted para-phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted triphenyl, substituted or unsubstituted triazine, substituted or unsubstituted quinoxalinyl, substituted or unsubstituted quinazolinyl, or substituted or unsubstituted benzoquinoxalinyl.

[0058] In Formulas 1 and 1-1 to 1-3 according to one embodiment, one or more nitrogen atoms of the indolocarbazole moiety are bonded to an aryl group and / or a nitrogen-containing heteroaryl group having strong electronic characteristics; preferably, at least one nitrogen atom of the indolocarbazole moiety may be bonded to a nitrogen-containing heteroaryl group. In indolocarbazole derivatives with high hole transport properties, it is important to select substituents with suitable electron transport properties, because band gap, electrical characteristics, interfacial characteristics, etc., can vary depending on the type of substituent and the bonding position.

[0059] In one embodiment, Ar1 and Ar2 can each independently be a nitrogen-containing heteroaryl group selected from formulas 2-1 and 2-2. Thus, the lifetime of an organic electroluminescent device comprising an organic electroluminescent compound according to one embodiment can be improved.

[0060]

[0061] In equations 2-1 and 2-2,

[0062] X independently represents N or CR 21 ;

[0063] R 11 and R 21 Each can independently represent hydrogen, deuterium, cyano, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl, or substituted or unsubstituted (3-membered to 30-membered) heteroaryl; or can be linked with adjacent substituents to form substituted or unsubstituted rings; and

[0064] n represents an integer from 1 to 4.

[0065] In one embodiment, in Formulas 2-1 and 2-2, at least one X can be N, for example, at least two X can be N. Specifically, Ar1 or Ar2 represented by Formula 2-1 can be a substituted or unsubstituted triazine group, and Ar1 or Ar2 represented by Formula 2-2 can be a substituted or unsubstituted naphthyl group, a substituted or unsubstituted quinoxalinyl group, a substituted or unsubstituted quinazolinyl group, or a substituted or unsubstituted benzoquinoxalinyl group.

[0066] In one embodiment, in Formula 1 and 1-1 to 1-3, L1 and L2 each independently represent a single bond, a substituted or unsubstituted (C1-C30) alkylene, a substituted or unsubstituted (C6-C30) arylene, a substituted or unsubstituted (3- to 30-membered) heteroarylene, or a substituted or unsubstituted (C3-C30) cycloalkylene, preferably each independently representing a single bond, a substituted or unsubstituted (C6-C18) arylene, or a substituted or unsubstituted (3- to 18-membered) heteroarylene, more preferably each independently representing a single bond, a substituted or unsubstituted (C6-C12) arylene, or a substituted or unsubstituted nitrogen-containing (5- to 20-membered) heteroarylene. For example, L1 and L2 can each independently be a single bond, a substituted or unsubstituted phenylene, a substituted or unsubstituted o-phenylene, a substituted or unsubstituted meta-phenylene, a substituted or unsubstituted para-phenylene, a substituted or unsubstituted naphthylene, a substituted or unsubstituted triphenylene, a substituted or unsubstituted triazine, a substituted or unsubstituted quinoxalinyl, a substituted or unsubstituted quinoxalinyl, or a substituted or unsubstituted benzoquinoxalinyl.

[0067] In one embodiment, in Formulas 1 and 1-1 to 1-3, R1 to R5 each independently represent hydrogen, deuterium, halogen, cyano, substituted or unsubstituted (C1-C30)alkyl, substituted or unsubstituted (C6-C30)aryl, substituted or unsubstituted (3- 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)alkyl The compounds may be 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, or substituted or unsubstituted (C1-C30)alkyl(C6-C30)arylamino; or may be linked with adjacent substituents to form substituted or unsubstituted rings. Preferably, R1 to R5 can each independently be hydrogen, deuterium, halogen, cyano, substituted or unsubstituted (C1-C10) alkyl, substituted or unsubstituted (C3-C10) cycloalkyl, or substituted or unsubstituted (C1-C10) alkoxy, more preferably hydrogen, deuterium, halogen, cyano, or substituted or unsubstituted (C1-C4) alkyl. For example, all R1 to R5 can be hydrogen.

[0068] In one embodiment, in Formula 1, a represents an integer from 1 to 4, and c represents an integer of 1 or 2. Additionally, b represents an integer of 1 or greater, preferably an integer from 1 to 20, or an integer from 1 to 14, more preferably an integer from 1 to 8, or an integer from 1 to 6.

[0069] In one embodiment, in equations 1-1 to 1-3, b can be an integer from 1 to 6, and d and e can each independently be an integer from 1 to 4.

[0070] In one embodiment, in Formulas 1-1 to 1-3, at least one of L1, L2, Ar1, and Ar2 may be a substituted or unsubstituted nitrogen-containing (5- to 30-membered) heteroaryl, preferably a substituted or unsubstituted nitrogen-containing (5- to 20-membered) heteroaryl, more preferably a substituted or unsubstituted nitrogen-containing (5- to 15-membered) heteroaryl.

[0071] In one embodiment, in formulas 1-1 to 1-3, Ar1 and Ar2 can each independently be hydrogen, substituted or unsubstituted (C6-C30) aryl, or substituted or unsubstituted (3-membered to 30-membered) heteroaryl; L1 and L2 can each independently be a single bond, substituted or unsubstituted (C6-C30) arylene, or substituted or unsubstituted (3-membered to 30-membered) heteroarylene; preferably, Ar1 and Ar2 can each independently be hydrogen, substituted or unsubstituted (C6-C18) aryl, or substituted or unsubstituted (3-membered to 10-membered) heteroarylene. The 8-membered heteroaryl group; L1 and L2 can each independently be a single bond, a substituted or unsubstituted (C6-C18) aryl group, or a substituted or unsubstituted (3- to 18-membered) heteroaryl group; more preferably, Ar1 and Ar2 can each independently be hydrogen, a substituted or unsubstituted (C6-C12) aryl group, or a substituted or unsubstituted nitrogen-containing (5- to 20-membered) heteroaryl group; L1 and L2 can each independently be a single bond, a substituted or unsubstituted (C6-C12) aryl group, or a substituted or unsubstituted nitrogen-containing (5- to 20-membered) heteroaryl group.

[0072] In one embodiment, in formulas 1-1 to 1-3, L1 can be a single bond or a substituted or unsubstituted nitrogen-containing (5- to 20-membered) heteroaryl group; Ar1 ​​can be hydrogen, a substituted or unsubstituted (C6-C18) aryl group, or a substituted or unsubstituted nitrogen-containing (5- to 20-membered) heteroaryl group; L2 can be a single bond or a substituted or unsubstituted (C6-C18) aryl group; and Ar2 can be hydrogen or a substituted or unsubstituted (C6-C18) aryl group.

[0073] According to one embodiment, the compound represented by Formula 1 can be further illustrated by the following compounds, but is not limited thereto:

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081] The compounds having Formula 1 according to this disclosure can be produced by synthetic methods known to those skilled in the art and, for example, by referring to the following reaction scheme 1, but are not limited thereto:

[0082] [Reaction Scheme 1]

[0083]

[0084] In reaction scheme 1, A, Ar1, Ar2, L1, and L2 are as defined in Equation 1.

[0085] As described above, exemplary synthetic examples of compounds represented by Formula 1 according to one embodiment have been described, but they are based on Buchwald-Hartwig cross-coupling reactions, N-arylation reactions, H-montage-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, dehydration cyclization reactions, SN1 substitution reactions, SN2 substitution reactions, phosphine-mediated reductive cyclization reactions, etc. Those skilled in the art will understand that the above reactions will continue even if other substituents defined in Formula 1 are bonded besides those described in the specific synthetic examples.

[0086] According to one embodiment, this disclosure provides an organic electroluminescent device comprising an organic electroluminescent compound having Formula 1.

[0087] The organic electroluminescent device according to this disclosure includes a first electrode; a second electrode; and at least one organic layer inserted between the first electrode and the second electrode. The organic layer may contain at least one organic electroluminescent compound having Formula 1. The organic layer may further contain at least one compound selected from the group consisting of arylamine-based compounds and styrylarylamine-based compounds. Furthermore, the organic layer may further contain at least one metal selected from the group consisting of metals of Group 1, Group 2, transition metals of Period 4, transition metals of Period 5, lanthanides, and d-transition elements, or at least one complex compound containing such metal.

[0088] According to one embodiment, the organic electroluminescent material can be used as a luminescent material for white organic light-emitting devices. Various structures have been proposed for white organic light-emitting devices based on the arrangement of R (red), G (green), B (blue), or YG (yellow-green) luminescent units, such as parallel side-by-side arrangements, stacked arrangements, or CCM (color conversion material) methods. Furthermore, the organic electroluminescent material according to one embodiment can also be applied to organic electroluminescent devices containing QDs (quantum dots).

[0089] Specifically, one of the first electrode and the second electrode can be an anode, and the other can be a cathode. The first electrode and the second electrode can each be formed using a transmissive conductive material, a transmissive-reflective conductive material, or a reflective conductive material. Depending on the types of materials forming the first electrode and the second electrode, the organic electroluminescent device can be a top-emitting type, a bottom-emitting type, or a side-emitting type. The organic layer can include a light-emitting layer, and can 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 injection layer, an intermediate layer, a hole blocking layer, an electron blocking layer, and an electron buffer layer.

[0090] A hole injection layer, a hole transport layer, an electron blocking layer, or a combination thereof can be used between the anode and the emissive layer. The hole injection layer can be multilayered to reduce the hole injection barrier (or hole injection voltage) from the anode to the hole transport layer or electron blocking layer, wherein each of the multilayers can use two compounds simultaneously. Furthermore, the hole injection layer can be doped with a p-type dopant. Additionally, an electron blocking layer can be placed between the hole transport layer (or hole injection layer) and the emissive layer, and can confine excitons within the emissive layer by blocking electrons from escaping from the emissive layer to prevent light leakage. The hole transport layer or electron blocking layer can be multilayered, and each layer can use multiple compounds.

[0091] An electron buffer layer, a hole blocking layer, an electron transport layer, 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 interface properties between the light-emitting layer and the electron injection layer, wherein each of the multilayers can use two compounds simultaneously. The hole blocking layer or electron transport layer can also be multilayered, wherein each layer can use multiple compounds. Furthermore, the electron injection layer can be doped with an n-type dopant.

[0092] A light-emitting auxiliary layer can be placed between the anode and the light-emitting layer, or between the cathode and the light-emitting layer. When placed between the anode and the light-emitting layer, it can promote hole injection and / or hole transport, or prevent electron overflow. When placed between the cathode and the light-emitting layer, it can promote electron injection and / or electron transport, or prevent hole overflow. Furthermore, a hole auxiliary layer can be placed between the hole transport layer (or hole injection layer) and the light-emitting layer, and can effectively promote or block the hole transport rate (or hole injection rate), thereby enabling charge balance control. When an organic electroluminescent device includes two or more hole transport layers, the further included hole transport layers can serve as hole auxiliary layers or electron blocking layers. The light-emitting auxiliary layer, hole auxiliary layer, or electron blocking layer can improve the efficiency and / or lifetime of the organic electroluminescent device.

[0093] In the organic electroluminescent device disclosed herein, at least one layer selected from chalcogenide layers, metal halide layers, and metal oxide layers (hereinafter, "surface layer") is preferably placed on one or more inner surfaces of one or two electrodes. Specifically, silicon and aluminum chalcogenide (including oxide) layers are preferably placed on the anode surface of the electroluminescent dielectric layer, and metal halide layers or metal oxide layers are preferably placed on the cathode surface of the electroluminescent dielectric layer. The operational stability of the organic electroluminescent device can be achieved through the surface layer. Preferably, the chalcogenide includes SiO₂. 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.

[0094] In the organic electroluminescent device of this disclosure, a mixed region of electron transport compound and reducing dopant, or a mixed region of hole transport compound and oxidizing dopant, can be placed on at least one surface of a pair of electrodes. In this case, the electron transport compound is reduced to anion, and thus it becomes easier to inject and transport electrons from the mixed region into the electroluminescent medium. Furthermore, the hole transport compound is oxidized to cation, and thus it becomes easier to inject and transport holes from the mixed region into the electroluminescent medium. Preferably, the oxidizing dopant includes various Lewis acids and acceptor compounds, and the reducing dopant includes alkali metals, alkali metal compounds, alkaline earth metals, rare earth metals, and mixtures thereof. The reducing dopant layer can be used as a charge-generating layer to prepare an organic electroluminescent device having two or more light-emitting layers and emitting white light.

[0095] An organic electroluminescent compound having Formula 1 can be included in the emissive layer. When used in the emissive layer, the organic electroluminescent compound having Formula 1 can be included as a host material. Preferably, the emissive layer may further contain at least one dopant, and if necessary, may further contain a compound other than the organic electroluminescent compound having Formula 1 of this disclosure as a second host material. In this document, the weight ratio of the first host material to the second host material is from 1:99 to 99:1. Any well-known phosphorescent host material can be used as the second host material.

[0096] The dopant included in the organic electroluminescent material of this disclosure may be at least one phosphorescent dopant or fluorescent dopant, preferably a phosphorescent dopant. The phosphorescent dopant material used in the organic electroluminescent device of this disclosure is not particularly limited, but may preferably be one or more metallized complexes of one or more metal atoms selected from the following: iridium (Ir), osmium (Os), copper (Cu), and platinum (Pt), more preferably one or more ortho-metallized complexes of one or more metal atoms selected from the following: iridium (Ir), osmium (Os), copper (Cu), and platinum (Pt), and even more preferably one or more ortho-metallized iridium complexes.

[0097] Compounds represented by formula 101 can be used as dopants, but are not limited to them:

[0098]

[0099] In Equation 101,

[0100] Wherein, L is selected from either structure 1 or 2:

[0101]

[0102] R 100 To R103 Each independently represents hydrogen, deuterium, halogen, halogen-substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (C6-C30) aryl, cyano, substituted or unsubstituted (3- to 30-membered) heteroaryl, or substituted or unsubstituted (C1-C30) alkoxy; or R 100 To R 103 It can be linked with one or more adjacent substituents to form substituted or unsubstituted fused rings, such as substituted or unsubstituted quinoline, substituted or unsubstituted benzofuranopyridine, substituted or unsubstituted benzothiophenopyridine, substituted or unsubstituted indenepyridine, substituted or unsubstituted benzofuranoquinoline, substituted or unsubstituted benzothiophenoquinoline, or substituted or unsubstituted indenequinoline;

[0103] R 104 To R 107 Each of these elements independently represents hydrogen, deuterium, halogen, halogen-substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (3- to 30-membered) heteroaryl, cyano, or substituted or unsubstituted (C1-C30) alkoxy; or R 104 To R 107 It can be linked with one or more adjacent substituents to form substituted or unsubstituted fused rings, such as substituted or unsubstituted naphthyl, substituted or unsubstituted fluorene, substituted or unsubstituted dibenzothiophene, substituted or unsubstituted dibenzofuran, substituted or unsubstituted indopyridine, substituted or unsubstituted benzofuran-pyridine, or substituted or unsubstituted benzothiophene-pyridine.

[0104] R 201 To R 211 Each can independently represent hydrogen, deuterium, halogen, halogen-substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C3-C30) cycloalkyl, or substituted or unsubstituted (C6-C30) aryl; or can be linked with one or more adjacent substituents to form a substituted or unsubstituted fused ring; and

[0105] s represents an integer from 1 to 3.

[0106] Specific examples of dopant compounds include, but are not limited to, the following:

[0107]

[0108]

[0109]

[0110]

[0111]

[0112] To form each layer of the organic electroluminescent device of this disclosure, dry film deposition methods such as vacuum evaporation, sputtering, plasma, ion plating, etc., or wet film deposition methods such as inkjet printing, nozzle printing, slot coating, spin coating, dip coating, flow coating, etc., can be used. When the layers are formed from the dopants and host compounds of this disclosure, co-evaporation or co-evaporation can be used, but are not limited thereto.

[0113] When using a wet film-forming method, a thin film can be formed by dissolving or diffusing the material forming each layer into any suitable solvent (such as ethanol, chloroform, tetrahydrofuran, dioxane, etc.). The solvent can be any solvent in which the material forming each layer can dissolve or diffuse and in which there are no problems with film-forming ability.

[0114] Co-deposition is a mixed deposition method in which two or more isomer materials are placed in respective single crucible sources and current is applied to two chambers simultaneously to cause the materials to evaporate and be mixed and deposited; and mixed deposition is a mixed deposition method in which two or more isomer materials are mixed in a crucible source before being deposited and then current is applied to a chamber to cause the materials to evaporate.

[0115] The organic electroluminescent device disclosed herein can be used to manufacture display devices such as smartphones, tablets, laptops, PCs, TVs, or display devices for vehicles, or lighting devices such as outdoor or indoor lighting.

[0116] In the following, the preparation methods and properties of the compounds according to the present disclosure will be explained with reference to representative compounds or intermediate compounds of the present disclosure, so as to provide a detailed understanding of the present disclosure.

[0117] [Example 1] Preparation of compound H-1

[0118]

[0119] Preparation of compound 1-1

[0120] 9-Bromophenanthrene (50 g, 194.4 mmol) was dissolved in 1300 mL of THF (tetrahydrofuran) in a flask, and n-butyllithium (97 mL, 194.4 mmol, in hexane, 2.0 M) was slowly added to the flask at -78 °C. After one hour, triisopropyl borate (89 mL, 388.8 mmol) was added to the flask and stirred at room temperature for 12 hours, followed by the addition of distilled water. After the reaction was complete, the organic layer was extracted with ethyl acetate, and the residual water was removed with magnesium sulfate, followed by drying and then vacuum distillation. Compound 1-1 (33.9 g, yield: 78%) was then given by recrystallization from ethyl acetate and hexane.

[0121] Preparation of compounds 1-2

[0122] Compound 1-1 (33.9 g, 152.66 mmol), 1,4-dibromo-2-nitrobenzene (35.7 g, 128.22 mmol), tetrakis(triphenylphosphine)palladium(0) (7.4 g, 63.61 mmol), sodium carbonate (40 g, 381.66 mmol), 600 mL of toluene, 200 mL of ethanol, and 200 mL of water were added to a flask and then refluxed with stirring for 5 hours. After the reaction was complete, the organic layer was extracted with ethyl acetate, and the residual water was removed with magnesium sulfate and then dried. The residue was then purified by column chromatography to obtain compound 1-2 (34 g, yield: 71%).

[0123] Preparation of compounds 1-3

[0124] Compounds 1-2 (34 g, 89.89 mmol), triphenylphosphine (58 g, 224.73 mmol), and 450 mL of dichlorobenzene were added to a flask and dissolved, then refluxed at 200 °C for 24 hours. After the reaction was complete, the solvent was removed by vacuum distillation, and then purified by column chromatography to obtain compounds 1-3 (22 g, yield: 70%).

[0125] Preparation of compounds 1-4

[0126] Compounds 1-3 (20 g, 57.76 mmol), 2-chloroaniline (12 mL, 115.53 mmol), tris(dibenzylacetone)dipalladium(0) (1.59 g, 1.732 mmol), tri-tert-butylphosphine (1.7 mL, 3.462 mmol), sodium tert-butoxide (16.6 g, 173.28 mmol), and 300 mL of toluene were added to a flask and refluxed with stirring for 5 hours. After the reaction was complete, the organic layer was extracted with ethyl acetate, and residual water was removed with magnesium sulfate and then dried. The resulting product was then purified by column chromatography to obtain compounds 1-4 (15 g, yield: 68%).

[0127] Preparation of compounds 1-5

[0128] Compounds 1-4 (14 g, 35.63 mmol), iodobenzene (6 mL, 53.45 mmol), cuprous iodide (3.4 g, 17.81 mmol), 1,2-diaminohexane (4 g, 35.63 mmol), cesium carbonate (23.2 g, 71.26 mmol), and 180 mL of xylene were added to a flask and refluxed with stirring for 24 hours. After the reaction was complete, the organic layer was extracted with ethyl acetate, and residual water was removed with magnesium sulfate and then dried. The resulting product was then purified by column chromatography to obtain compounds 1-5 (15.5 g, yield: 92%).

[0129] Preparation of compounds 1-6

[0130] Compounds 1-5 (15.5 g, 33.05 mmol), palladium(II) acetate (1.5 g, 6.610 mmol), tricyclohexylphosphine tetrafluoroborate (3.6 g, 9.915 mmol), cesium carbonate (32 g, 99.15 mmol), and 165 mL of dimethylaminopyridine were added to a flask and refluxed with stirring for 1 hour. After the reaction was complete, the organic layer was extracted with ethyl acetate, and residual water was removed with magnesium sulfate and then dried. The resulting product was then purified by column chromatography to obtain compounds 1-6 (3.2 g, yield: 22%).

[0131] Preparation of compound H-1

[0132] Compounds 1-6 (3.2 g, 33.05 mmol), 2-chloro-3-phenylquinoxaline (2.1 g, 8.877 mmol), potassium carbonate (1 g, 7.398 mmol), and 40 mL of dimethylaminopyridine were added to a flask and refluxed with stirring for 24 hours. After the reaction was complete, the organic layer was extracted with ethyl acetate, and residual water was removed with magnesium sulfate and then dried. The resulting product was then purified by column chromatography to obtain compound H-1 (1.5 g, yield: 32%).

[0133] 1H NMR (600MHz, CDCl3, δ) 8.74 (s, 1H), 8.33-8.32 (d, J=6.0Hz, 1H), 8.15-8.14 (d, J=6.0Hz, 1H), 7.91-7.90(m, 1H), 7.84-8.73(m, 2H), 7.80-7.78(m, 5H), 7.77-7.69(m, 5H), 7.64-7.63(m.1H), 7.60-7.59(m, 1H), 7.50-7.49(d, J=6 .0Hz, 1H), 7.43-7.41 (m, 3H), 7.36-7.34 (t, J=6.0Hz, 1H), 7.28-7.27 (m, 1H)

[0134] MW Melting point H-1 636.76 317.3℃

[0135] [Example 2] Preparation of compound H-56

[0136]

[0137] Preparation of compound H-56

[0138] Compounds 1-6 (4 g, 9.24 mmol), 2-chloro-4,6-diphenyl-1,3,5-triazine (3.7 g, 10.17 mmol), potassium carbonate (1.3 g, 9.24 mmol), 4-dimethylpyridine (0.5 g, 4.62 mmol), and 50 mL of dimethylformaldehyde were added to a flask and refluxed with stirring for 24 hours. After the reaction was complete, the organic layer was extracted with ethyl acetate, and residual water was removed with magnesium sulfate and then dried. The resulting product was then purified by column chromatography to obtain compound H-56 (1.3 g, yield: 22%).

[0139] 1H NMR (600MHz, CDCl3, δ) 9.28-9.27 (m, 1H), 9.19-9.17 (m, 1H), 9.03-9.02 (m, 1H), 9.00 (s, 1H), 8.86-8.82 ( m, 5H), 7.70-7.64 (m, 7H), 7.58-7.54 (m, 3H), 7.43-7.38 (m, 3H), 7.08 (s, 1H), 6.88-6.85 (t, J=7.8Hz, 1H)

[0140] MW Tg Melting point H-56 663.78 135.23℃ 363℃

[0141] The following will explain the preparation method and characteristics of organic electroluminescent devices incorporating the organic electroluminescent compounds of this disclosure in order to provide a detailed understanding of this disclosure.

[0142] [Apparatus Examples 1 and 2] Production of OLEDs wherein the compound according to the present disclosure is deposited as the host.

[0143] An OLED device comprising the compounds disclosed herein is produced. First, a transparent electrode indium tin oxide (ITO) film (10 Ω / sq) (GEOMATEC CO., LTD., Japan) on a glass substrate used in the OLED device is subjected to ultrasonic washing sequentially with acetone, ethanol, and distilled water, and then stored in isopropanol. The ITO substrate is then mounted on a substrate holder of a vacuum vapor deposition apparatus. Compound HI-1 is introduced into the chamber of the vacuum vapor deposition apparatus, and the pressure in the chamber is then controlled to 10 Ω / sq. -6 Next, a current is applied to the chamber to evaporate the introduced material, thereby forming a first hole injection layer with a thickness of 80 nm on the ITO substrate. Then, compound HI-2 is introduced into another chamber of the vacuum vapor deposition apparatus, and the compound is evaporated by applying a current to the chamber, thereby forming a second hole injection layer with a thickness of 5 nm on the first hole injection layer. Then, compound HT-1 is introduced into another chamber of the vacuum vapor deposition apparatus, and the compound is evaporated by applying a current to the chamber, thereby forming a first hole transport layer with a thickness of 10 nm on the second hole injection layer. Then, compound HT-2 is introduced into another chamber of the vacuum vapor deposition apparatus, and the compound is evaporated by applying a current to the chamber, thereby forming a second hole transport layer with a thickness of 60 nm on the first hole transport layer. After forming the hole injection layer and the hole transport layer, the light-emitting layer is formed thereon as follows: Compound H-1 (Apparatus Example 1) or H-56 (Apparatus Example 2) from Table 1 is introduced as a host material into one chamber of a vacuum vapor deposition apparatus, and compound D-39 is introduced as a dopant into another chamber. The two host materials are evaporated at different rates, and a dopant is deposited at a doping amount of 3 wt% to form a light-emitting layer with a thickness of 40 nm on the hole transport layer. Next, compounds ET-1 and EI-1 are evaporated and deposited at a 1:1 ratio to form an electron transport layer with a thickness of 35 nm on the light-emitting layer. After depositing compound EI-1 as an electron injection layer with a thickness of 2 nm on the electron transport layer, an Al cathode with a thickness of 80 nm is deposited on the electron injection layer using another vacuum vapor deposition apparatus. Thus, an OLED is produced.

[0144] [Comparison Examples 1 and 2] Production of OLEDs in which conventional compounds are deposited as the host material

[0145] The OLED was produced in the same manner as in Device Example 1, except that compound CBP (Comparative Example 1) or compound X (Comparative Example 2) was used as the host of the light-emitting layer, respectively.

[0146] The compounds used in apparatus examples 1 and 2, as well as comparative examples 1 and 2, are specifically shown in Table 1 below.

[0147] Table 1

[0148]

[0149] Evaluation: Characterization of Organic Electroluminescent Devices

[0150] Table 2 below shows the results of the driving voltage, efficiency, and color coordinates of the organic electroluminescent devices of the device examples 1 and 2 and comparative examples 1 and 2 produced as described above, at a brightness of 5,000 nits, as well as the time (lifetime; T95) taken to decrease from 100% to 95% at a brightness of 5,000 nits.

[0151] Table 2

[0152]

[0153] Referring to Table 2 above, compared with the OLED using conventional host materials such as CBP in Comparative Example 1, the OLEDs using an organic electroluminescent compound as the host according to one embodiment in Device Examples 1 and 2 exhibit far superior performance in terms of driving voltage, luminous efficiency, and lifetime.

[0154] Furthermore, it was confirmed that the OLED of Comparative Example 2 uses compound X with an indolo[2,3-a]carbazole derivative as its basic framework; however, it is significantly lower in terms of luminous efficiency and lifetime than the OLED according to the device example. Compound X is indolo[2,3-a]carbazole as its basic framework, in which the electron mobility is slowed down due to the steric hindrance between the LUMO and the phenanthrene phenyl ring fused to its end, resulting in reduced device efficiency and lifetime.

[0155] In other words, it can be confirmed from the device examples and comparative examples that, compared with organic electroluminescent devices containing conventional organic electroluminescent compounds, organic electroluminescent devices containing organic electroluminescent compounds according to the present disclosure have low driving voltage, high luminous efficiency, and significantly improved lifetime characteristics.

Claims

1. An organic electroluminescent compound, represented by the following formula 1-2: in, Ar1 represents a substituted or unsubstituted triazine group, a substituted or unsubstituted quinoxaline group, or a substituted or unsubstituted quinazolinine group, wherein the substituents of the substituted triazine group, the substituted quinoxaline group, and the substituted quinazolinine group are selected from at least one of the following groups: deuterium; and unsubstituted (C6-C30) aryl group; Ar2 represents a (C6-C30) aryl group that is either deuterated or unsubstituted; L1 and L2 each represent a single bond independently; R1 and R3 through R5 each independently represent hydrogen or deuterium; a, d, and e represent integers from 1 to 4; c represents an integer of 1 or 2; and When a to e are 2 or greater, each R1, each R3, each R4, or each R5 can be the same or different.

2. The organic electroluminescent compound according to claim 1, wherein, The compounds represented by formulas 1-2 in claim 1 are selected from the group consisting of:

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

4. The organic electroluminescent device according to claim 3, wherein, The organic electroluminescent compound is contained in the light-emitting layer.

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