Organic electroluminescent compound and organic electroluminescent device including the same

Abstract

To provide an organic electroluminescent compound and an organic electroluminescent device including the compound.SOLUTION: The present disclosure relates to an organic electroluminescent compound and an organic electroluminescent device including the compound. By using the organic electroluminescent compound according to the present disclosure, an organic electroluminescent device having improved driving voltage and / or luminous efficiency can be provided.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] In 1987, Tang et al. at Eastman Kodak first developed a small molecule green organic electroluminescent device (OLED) using a TPD / Alq3 bilayer consisting of an emissive layer and a charge transport layer. Since then, the development of OLEDs has progressed rapidly, and OLEDs have been commercialized. OLEDs convert electrical energy into light by applying electricity to organic light-emitting materials, and typically include an anode, a cathode, and an organic layer between the two electrodes.

[0003] The organic layer of an organic electroluminescent 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, an electron buffer layer, a hole blocking layer, an electron transport layer, an electron injection layer, etc. The materials used in the organic layer may be classified according to their functions into hole injection materials, hole transport materials, hole auxiliary materials, light-emitting auxiliary materials, electron blocking materials, light-emitting materials (including host materials and dopant materials), electron buffer materials, hole blocking materials, electron transport materials, electron injection materials, etc.

[0004] In recent years, attempts have been made to improve the properties of organic electroluminescent devices by optimizing the optical thickness between the anode and cathode to improve color purity and / or light extraction efficiency. For example, to achieve a specific color and satisfy the requirements for efficient light extraction of a specific wavelength, the thickness of the organic layers included in the device and the refractive index of the organic layers can be adjusted, and these two factors complement each other. That is, when a high refractive index material is used to achieve specific optical properties, the device thickness can be reduced. This allows for thinner devices and reduced material usage. Therefore, the development of organic electroluminescent materials with high refractive index properties is needed. Previous studies have already investigated how specific materials exhibit high refractive indexes (Non-Patent Document 1). However, most papers and patents only disclose comparative results for similar structures and do not accurately match the trends across various structures (Non-Patent Document 2).

[0005] Additionally, although US Pat. No. 6,299,629 discloses compounds in which a diarylamine is attached to the 5-position of benzo[b]fluorene, there remains a need for organic electroluminescent compounds with higher refractive indices. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Korean Patent Application Publication No. 2017-0124957 [Non-patent literature]

[0007] [Non-Patent Document 1] J.phys.Chem.A.1999,103,1818-1821 [Non-patent document 2] J.Mater.Chem.,2011,21,19187-19202 Summary of the Invention [Problem to be solved by the invention]

[0008] The present disclosure has at least one of the following objectives: The present disclosure provides an organic electroluminescent compound having a novel structure. The present disclosure provides a hole transport material including an organic electroluminescent compound having a novel structure. The present disclosure provides an organic electroluminescent compound having a higher refractive index than conventional organic electroluminescent compounds. [Means for solving the problem]

[0009] The present inventors have found that compounds in which a specific position of benzo[b]fluorene is substituted with an amine group have effective properties as organic electroluminescent compounds and can also provide a high refractive index.

[0010] Specifically, the objective is to provide a compound of formula 1: [ka] (In the formula, Ar1 and Ar2 each independently represent hydrogen, deuterium, halogen, cyano, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (3-7 membered) heterocycloalkyl, substituted or unsubstituted (C6-C30) aryl, or substituted or unsubstituted (3-30 membered) heteroaryl, or Ar1 and Ar2 may be bonded to each other to form a fused ring; R1 to R6 each independently represent hydrogen, deuterium, halogen, cyano, substituted or unsubstituted (C1 to C30) alkyl, substituted or unsubstituted (C3 to C30) cycloalkyl, substituted or unsubstituted (3 to 7-membered) heterocycloalkyl, substituted or unsubstituted (C6 to C30) aryl, substituted or unsubstituted (3 to 30-membered) heteroaryl, substituted or unsubstituted tri(C1 to C30) alkylsilyl, substituted or unsubstituted di(C1 to C30) alkyl(C6 to C30) arylsilyl, substituted or unsubstituted (C1 to C30) alkyldi(C6 to C30) arylsilyl, or substituted or unsubstituted tri(C6 to C30) arylsilyl; R7~R 10 are each independently hydrogen, deuterium, halogen, cyano, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (3-7 membered) heterocycloalkyl, substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (3-30 membered) heteroaryl, substituted or unsubstituted tri(C1-C30) alkylsilyl, substituted or unsubstituted di(C1-C30) alkyl(C6-C30) arylsilyl, substituted or unsubstituted (C1-C30) alkyldi(C6-C30) arylsilyl, substituted or unsubstituted tri(C6-C30) arylsilyl, or [ka] represents R7~R 10 At least one of [ka] provided that: L1 represents a single bond, a substituted or unsubstituted (C6 to C30) arylene, or a substituted or unsubstituted (3 to 30-membered) heteroarylene; Ar3 and Ar4 are each independently hydrogen, deuterium, a substituted or unsubstituted (C1-C30) alkyl, a substituted or unsubstituted (C3-C30) cycloalkyl, a substituted or unsubstituted (3-7 membered) heterocycloalkyl, a substituted or unsubstituted (C6-C30) aryl, or a substituted or unsubstituted (3-30 membered) heteroaryl, or Ar3 and Ar4 can be bonded to each other to form a fused ring; and * indicates the position where it is bonded to benzofluorene) This can be achieved by an organic electroluminescent compound represented by:

[0011] Advantageous Effects of the Invention The present disclosure provides at least one of the following advantages: According to the present disclosure, it is possible to obtain an organic electroluminescent compound, preferably a hole transport material, having a novel structure that can be used in an organic electroluminescent device. The organic electroluminescent compound according to the present disclosure has a higher refractive index than conventional compounds having a similar structure. By using the organic electroluminescent compound according to the present disclosure, it is possible to manufacture a thinner organic electroluminescent device and reduce the amount of material used. By using the organic electroluminescent compound according to the present disclosure, it is possible to obtain an organic electroluminescent device with improved driving voltage and / or luminous efficiency. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present disclosure will be described in detail below. However, the following description is intended to illustrate the present invention and is not intended to limit the scope of the present invention.

[0013] The term "organic electroluminescent compound" in the present disclosure means a compound that can be used in an organic electroluminescent device and can be included in any layer that constitutes the organic electroluminescent device as needed.

[0014] In the present disclosure, the term "organic electroluminescent material" refers to a material that can be used in an organic electroluminescent device and can include at least one compound. The organic electroluminescent material can be included in any layer that constitutes an organic electroluminescent device, as needed. For example, the organic electroluminescent material can be a hole injection material, a hole transport material, a hole auxiliary material, a light-emitting auxiliary material, an electron blocking material, a light-emitting material, an electron buffer material, a hole blocking material, an electron transport material, or an electron injection material.

[0015] In this specification, the term "(C1-C30) alkyl" refers to a straight-chain or branched alkyl having 1 to 30 carbon atoms constituting the chain, preferably 1 to 20, and more preferably 1 to 10. Examples of the alkyl include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, and sec-butyl. The term "(C2-C30) alkenyl" refers to a straight-chain or branched alkenyl having 2 to 30 carbon atoms constituting the chain, preferably 2 to 20, and more preferably 2 to 10. Examples of the alkenyl include vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, and 2-methylbut-2-enyl. The term "(C2-C30)alkynyl" refers to a straight-chain or branched alkynyl having 2 to 30 carbon atoms constituting the chain, preferably 2 to 20, more preferably 2 to 10. Examples of the alkynyl include ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, and 1-methylpent-2-ynyl. The term "(C3-C30)cycloalkyl" refers to a monocyclic or polycyclic hydrocarbon having 3 to 30 ring skeletal carbon atoms, preferably 3 to 20, more preferably 3 to 7. Examples of the cycloalkyl include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopentylmethyl, and cyclohexylmethyl. The term "(3- to 7-membered)heterocycloalkyl" means a cycloalkyl having 3 to 7, preferably 5 to 7, ring skeletal atoms and containing at least one heteroatom selected from the group consisting of B, N, O, S, Si, and P, preferably at least one heteroatom selected from the group consisting of O, S, and N. The heterocycloalkyl may include tetrahydrofuran, pyrrolidine, thiolane, tetrahydropyran, etc. The term "(C6-C30)aryl(ene)" means a cycloalkyl which may be partially saturated,It means a monocyclic or fused ring radical derived from an aromatic hydrocarbon having 6 to 30 ring skeletal carbon atoms. The number of ring skeletal carbon atoms is preferably 6 to 25, more preferably 6 to 18. The above aryl includes those having a spiro structure. Examples of the above aryl include phenyl, biphenyl, terphenyl, naphthyl, binaphthyl, phenylnaphthyl, naphthylphenyl, phenylterphenyl, fluorenyl, phenylfluorenyl, diphenylfluorenyl, benzofluorenyl, dibenzofluorenyl, phenanthrenyl, phenylphenanthrenyl, anthracenyl, indenyl, triphenylenyl, pyrenyl, tetracenyl, perylenyl, chrysenyl, naphthacenyl, fluoranthenyl, spirobifluorenyl, azulenyl, tetramethyldihydrophenanthrenyl, and the like. More specifically, examples of aryl include phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, benzanthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, 9-phenanthryl, naphthacenyl, pyrenyl, 1-chrysenyl, 2-chrysenyl, 3-chrysenyl, 4-chrysenyl, 5-chrysenyl, 6-chrysenyl, benzo[c]phenanthryl, benzo[g]chrysenyl, 1-triphenylenyl, 2-triphenylenyl, 3-triphenylenyl, 4-triphenylenyl, 1-fluorenyl, 2-fluorenyl, 3-fluorenyl, 4-fluorenyl, 9-fluorenyl, benzo[a]fluorenyl, and benz[a]fluorenyl. benzo[b]fluorenyl, benzo[c]fluorenyl, dibenzofluorenyl, 2-biphenylyl, 3-biphenylyl, 4-biphenylyl, 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, m-quaterphenyl, 3-fluoranthenyl, 4-fluoranthenyl, 8-fluoranthenyl, 9-fluoranthenyl, benzofluoranthenyl, o-tolyl, m-tolyl, p-tolyl, 2,3-xylyl, 3,4-xylyl, 2,5-xylyl, mesityl, o-cumenyl, m-cumenyl, p-cumenyl, p-tert-butylphenyl,p-(2-phenylpropyl)phenyl, 4'-methylbiphenylyl, 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, 11,11-dimethyl-1-benzo[a]fluorenyl, 11,11-dimethyl-2-benz[a]fluorenyl benzo[a]fluorenyl, 11,11-dimethyl-3-benzo[a]fluorenyl, 11,11-dimethyl-4-benzo[a]fluorenyl, 11,11-dimethyl-5-benzo[a]fluorenyl, 11,11-dimethyl-6-benzo[a]fluorenyl, 11,11-dimethyl-7-benzo[a]fluorenyl, 11,11-dimethyl-8-benzo[a]fluorenyl, 11,11-dimethyl-9-benzo[a]fluorenyl, 11,11-dimethyl-10-benzo[a]fluorenyl, 11,11-dimethyl-1-benzo[b]fluorenyl, 1 1,11-dimethyl-2-benzo[b]fluorenyl, 11,11-dimethyl-3-benzo[b]fluorenyl, 11,11-dimethyl-4-benzo[b]fluorenyl, 11,11-dimethyl-5-benzo[b]fluorenyl, 11,11-dimethyl-6-benzo[b]fluorenyl, 11,11-dimethyl-7-benzo[b]fluorenyl, 11,11-dimethyl-8-benzo[b]fluorenyl, 11,11-dimethyl-9-benzo[b]fluorenyl, 11,11-dimethyl-10-benzo[b]fluorenyl, 11,11-dimethyl-1- Benzo[c]fluorenyl, 11,11-dimethyl-2-benzo[c]fluorenyl, 11,11-dimethyl-3-benzo[c]fluorenyl, 11,11-dimethyl-4-benzo[c]fluorenyl, 11,11-dimethyl-5-benzo[c]fluorenyl, 11,11-dimethyl-6-benzo[c]fluorenyl, 11,11-dimethyl-7-benzo[c]fluorenyl, 11,11-dimethyl-8-benzo[c]fluorenyl, 11,11-dimethyl-9-benzo[c]fluorenyl, 11,11-dimethyl-10-benzo[c]fluorenyl,11,11-diphenyl-1-benzo[a]fluorenyl, 11,11-diphenyl-2-benzo[a]fluorenyl, 11,11-diphenyl-3-benzo[a]fluorenyl, 11,11-diphenyl-4-benzo[a]fluorenyl, 11,11-diphenyl-5-benzo[a]fluorenyl, 11,11-diphenyl-6-benzo[a]fluorenyl, 11,11-diphenyl-7-benzo[a]fluorenyl, 11,11-diphenyl-8-benzo[a]fluorenyl, 11,11-diphenyl-9-benzo[a]fluorenyl, 11,11-diphenyl-10-benzo[a]fluorenyl, 11,11-diphenyl-1-benzo[b]fluorenyl, 11,11-diphenyl-2-benzo[b]fluorenyl, 11,11-diphenyl-3-benzo[b]fluorenyl, 11,11-diphenyl-4-benzo[b]fluorenyl, 11,11-diphenyl-5-benzo[b]fluorenyl, 11,11-diphenyl-6-benzo[b]fluorenyl, 11,11-diphenyl-7-benzo[b]fluorenyl, 11,11-diphenyl-8-benzo[b]fluorenyl , 11,11-diphenyl-9-benzo[b]fluorenyl, 11,11-diphenyl-10-benzo[b]fluorenyl, 11,11-diphenyl-1-benzo[c]fluorenyl, 11,11-diphenyl-2-benzo[c]fluorenyl, 11,11-diphenyl-3-benzo[c]fluorenyl, 11,11-diphenyl-4-benzo[c]fluorenyl, 11,11-diphenyl-5-benzo[c]fluorenyl, 11,11-diphenyl-6-benzo[c]fluorenyl, 11,11-diphenyl-7-benzo[c]fluorenyl Examples of the fluorenyl compounds include 11,11-diphenyl-8-benzo[c]fluorenyl, 11,11-diphenyl-9-benzo[c]fluorenyl, 11,11-diphenyl-10-benzo[c]fluorenyl, 9,9,10,10-tetramethyl-9,10-dihydro-1-phenanthrenyl, 9,9,10,10-tetramethyl-9,10-dihydro-2-phenanthrenyl, 9,9,10,10-tetramethyl-9,10-dihydro-3-phenanthrenyl, and 9,9,10,10-tetramethyl-9,10-dihydro-4-phenanthrenyl.

[0016] The term "(3- to 30-membered) heteroaryl(ren)" refers to an aryl group having 3 to 30 skeletal ring atoms and containing at least one heteroatom selected from the group consisting of B, N, O, S, Si, and P. The number of heteroatoms is preferably 1 to 4. The heteroaryl(ren) may be a monocyclic ring or a fused ring fused with at least one benzene ring, and may be partially saturated. In addition, the heteroaryl(ren) may include a form in which at least one heteroaryl or aryl group is bonded to the heteroaryl group by a single bond, and may also include a spiro structure. The heteroaryls mentioned above include monocyclic heteroaryls such as furyl, thiophenyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, triazinyl, tetrazinyl, triazolyl, tetrazolyl, furazanyl, pyridyl, pyrazinyl, pyrimidinyl, and pyridazinyl; and benzofuranyl, benzothiophenyl, isobenzofuranyl, dibenzofuranyl, dibenzothiophenyl, dibenzoselenophenyl, naphthobenzofuranyl, naphthobenzothiophenyl, benzofuroquinolyl, benzofuroquinazolinyl, benzofuronaphthyridinyl, benzofuropyrimidinyl, naphthofuropyrimidinyl, benzothienoquinolyl, benzothienoquinazolinyl, benzothienonaphthyridinyl, benzothienopyrimidinyl, and naphthobenzopyrimidinyl. tothienopyrimidinyl, pyrimidoindolyl, benzopyrimidoindolyl, benzofuropyrazinyl, naphthofuropyrazinyl, benzothienopyrazinyl, naphthothienopyrazinyl, pyrazinoindolyl, benzopyrazinoindolyl, benzimidazolyl, benzothiazolyl, benzisothiazolyl, benzisoxazolyl, benzoxazolyl, isoindolyl, indolyl, benzoindolyl, indazolyl, benzothiadiazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl, benzoquinazolinyl, quinoxalinyl, benzoquinoxalinyl, naphthyridinyl, carbazolyl, benzocarbazolyl, dibenzocarbazolyl, phenoxazinyl, phenothiazinyl, phenanthridinyl, benzodioxolyl, dihydroacridinyl, benzotriazolephenazinyl, imidazopyridyl,Condensed ring heteroaryls such as chromenoquinazolinyl, thiochromenoquinazolinyl, dimethylbenzoperimidinyl, indolocarbazolyl, indenocarbazolyl, etc. More specifically, heteroaryls include 1-pyrrolyl, 2-pyrrolyl, 3-pyrrolyl, pyrazinyl, 2-pyridyl, 2-pyrimidinyl, 4-pyrimidinyl, 5-pyrimidinyl, 6-pyrimidinyl, 1,2,3-triazin-4-yl, 1,2,4-triazin-3-yl, 1,3,5-triazin-2-yl, 1-imidazolyl, 2-imidazolyl, 1-pyrazolyl, 1-indolinyl, 2-indolinyl, 3-indolinyl, 5-indolinyl, 6-indolinyl, 7-indolinyl, 8-indolinyl, 2-Imidazopyridyl, 3-Imidazopyridyl, 5-Imidazopyridyl, 6-Imidazopyridyl, 7-Imidazopyridyl, 8-Imidazopyridyl, 3-Pyridyl, 4-Pyridyl, 1-Indolyl, 2-Indolyl, 3-Indolyl, 4-Indolyl, 5-Indolyl, 6-Indolyl, 7-Indolyl, 1-Isoindolyl, 2-Isoindolyl, 3-Isoindolyl, 4-Isoindolyl, 5-Isoindolyl, 6-Isoindolyl, 7-Isoindolyl, 2-Furyl, 3-Furyl, 2-Benzofuranyl, 3 -benzofuranyl, 4-benzofuranyl, 5-benzofuranyl, 6-benzofuranyl, 7-benzofuranyl, 1-isobenzofuranyl, 3-isobenzofuranyl, 4-isobenzofuranyl, 5-isobenzofuranyl, 6-isobenzofuranyl, 7-isobenzofuranyl, 2-quinolyl, 3-quinolyl, 4-quinolyl, 5-quinolyl, 6-quinolyl, 7-quinolyl, 8-quinolyl, 1-isoquinolyl, 3-isoquinolyl, 4-isoquinolyl, 5-isoquinolyl, 6-isoquinolyl, 7-isoquinolyl, 8-isoquinolyl Noryl, 2-quinoxalinyl, 5-quinoxalinyl, 6-quinoxalinyl, 1-carbazolyl, 2-carbazolyl, 3-carbazolyl, 4-carbazolyl, 9-carbazolyl, azacarbazolyl-1-yl, azacarbazolyl-2-yl, azacarbazolyl-3-yl, azacarbazolyl-4-yl, azacarbazolyl-5-yl, azacarbazolyl-6-yl, azacarbazolyl-7-yl, azacarbazolyl-8-yl, azacarbazolyl-9-yl, 1-phenanthridinyl, 2-phenanthridinyl,3-Phenanthridinyl, 4-Phenanthridinyl, 6-Phenanthridinyl, 7-Phenanthridinyl, 8-Phenanthridinyl, 9-Phenanthridinyl, 10-Phenanthridinyl, 1-Acridinyl, 2-Acridinyl, 3-Acridinyl, 4-Acridinyl, 9-Acridinyl, 2-Oxazolyl, 4-Oxazolyl, 5-Oxazolyl, 2-Oxadiazolyl, 5-Oxadiazolyl, 3-Furazanyl, 2-Thienyl, 3-Thienyl, 2-Methylpyrrol-1-yl, 2-Methylpyrrol-3-yl, 2-Methylpyrrol-4-yl, 2 -methylpyrrol-5-yl, 3-methylpyrrol-1-yl, 3-methylpyrrol-2-yl, 3-methylpyrrol-4-yl, 3-methylpyrrol-5-yl, 2-tert-butylpyrrol-4-yl, 3-(2-phenylpropyl)pyrrol-1-yl, 2-methyl-1-indolyl, 4-methyl-1-indolyl, 2-methyl-3-indolyl, 4-methyl-3-indolyl, 2-tert-butyl-1-indolyl, 4-tert-butyl-1-indolyl, 2-tert-butyl-3-indolyl, 4-tert-butyl-3-indolyl 1-dibenzofuranyl, 2-dibenzofuranyl, 3-dibenzofuranyl, 4-dibenzofuranyl, 1-dibenzothiophenyl, 2-dibenzothiophenyl, 3-dibenzothiophenyl, 4-dibenzothiophenyl, 1-naphtho-[1,2-b]-benzofuranyl, 2-naphtho-[1,2-b]-benzofuranyl, 3-naphtho-[1,2-b]-benzofuranyl, 4-naphtho-[1,2-b]-benzofuranyl, 5-naphtho-[1,2-b]-benzofuranyl, 6-naphtho-[1,2-b]-benzofuranyl, 7-naphtho-[1,2-b]-benzo furanyl, 8-naphtho-[1,2-b]-benzofuranyl, 9-naphtho-[1,2-b]-benzofuranyl, 10-naphtho-[1,2-b]-benzofuranyl, 1-naphtho-[2,3-b]-benzofuranyl, 2-naphtho-[2,3-b]-benzofuranyl, 3-naphtho-[2,3-b]-benzofuranyl, 4-naphtho-[2,3-b]-benzofuranyl, 5-naphtho-[2,3-b]-benzofuranyl, 6-naphtho-[2,3-b]-benzofuranyl, 7-naphtho-[2,3-b]-benzofuranyl, 8-naphtho-[2,3-b]-benzofuranyl,9-Naphtho-[2,3-b]-benzofuranyl, 10-Naphtho-[2,3-b]-benzofuranyl, 1-Naphtho-[2,1-b]-benzofuranyl, 2-Naphtho-[2,1-b]-benzofuranyl, 3-Naphtho-[2,1-b]-benzofuranyl, 4-Naphtho-[2,1-b]-benzofuranyl, 5-Naphtho-[2,1-b]-benzofuranyl, 6-Naphtho-[2,1-b]-benzofuranyl, 7-Naphtho-[2,1-b]-benzofuranyl, 8-Naphtho-[2,1-b]-benzofuranyl, 9-Naphtho-[2,1-b]-benzofuranyl, 10-Naphtho 1-naphtho-[1,2-b]-benzofuranyl, 1-naphtho-[1,2-b]-benzothiophenyl, 2-naphtho-[1,2-b]-benzothiophenyl, 3-naphtho-[1,2-b]-benzothiophenyl, 4-naphtho-[1,2-b]-benzothiophenyl, 5-naphtho-[1,2-b]-benzothiophenyl, 6-naphtho-[1,2-b]-benzothiophenyl, 7-naphtho-[1,2-b]-benzothiophenyl, 8-naphtho-[1,2-b]-benzothiophenyl, 9-naphtho-[1,2-b]-benzothiophenyl, 10-naphtho-[1,2-b]- Benzothiophenyl, 1-naphtho-[2,3-b]-benzothiophenyl, 2-naphtho-[2,3-b]-benzothiophenyl, 3-naphtho-[2,3-b]-benzothiophenyl, 4-naphtho-[2,3-b]-benzothiophenyl, 5-naphtho-[2,3-b]-benzothiophenyl, 1-naphtho-[2,1-b]-benzothiophenyl, 2-naphtho-[2,1-b]-benzothiophenyl, 3-naphtho-[2,1-b]-benzothiophenyl, 4-naphtho-[2,1-b]-benzothiophenyl, 5-naphtho-[2,1-b]-benzothiophenyl benzothiophenyl, 6-naphtho-[2,1-b]-benzothiophenyl, 7-naphtho-[2,1-b]-benzothiophenyl, 8-naphtho-[2,1-b]-benzothiophenyl, 9-naphtho-[2,1-b]-benzothiophenyl, 10-naphtho-[2,1-b]-benzothiophenyl, 2-benzofuro[3,2-d]pyrimidinyl, 6-benzofuro[3,2-d]pyrimidinyl, 7-benzofuro[3,2-d]pyrimidinyl, 8-benzofuro[3,2-d]pyrimidinyl, 9-benzofuro[3,2-d]pyrimidinyl, 2-benzothio[3,2-d]pyrimidinyl,6-benzothio[3,2-d]pyrimidinyl, 7-benzothio[3,2-d]pyrimidinyl, 8-benzothio[3,2-d]pyrimidinyl, 9-benzothio[3,2-d]pyrimidinyl, 2-benzofuro[3,2-d]pyrazinyl, 6-benzofuro[3,2-d]pyrazinyl, 7-benzofuro[3,2-d]pyrazinyl, 8-benzofuro[3,2-d]pyrazinyl, 9-benzofuro[3,2-d]pyrazinyl, 2-benzothio[3,2-d]pyrazinyl, 6-benzothio[3,2-d]pyri Examples of "halogen" include azininyl, 7-benzothio[3,2-d]pyrazinyl, 8-benzothio[3,2-d]pyrazinyl, 9-benzothio[3,2-d]pyrazinyl, 1-silafluorenyl, 2-silafluorenyl, 3-silafluorenyl, 4-silafluorenyl, 1-germafluorenyl, 2-germafluorenyl, 3-germafluorenyl, 4-germafluorenyl, 1-dibenzoselenophenyl, 2-dibenzoselenophenyl, 3-dibenzoselenophenyl, 4-dibenzoselenophenyl, and the like. "Halogen" includes F, Cl, Br, and I.

[0017] Additionally, "ortho (o-)," "meta (m-)," and "para (p-)" are prefixes that indicate the relative positions of substituents, respectively. Ortho indicates that two substituents are adjacent to each other; for example, when two substituents in a benzene derivative occupy the 1st and 2nd positions, it is called the ortho position. Meta indicates that two substituents are at the 1st and 3rd positions; for example, when two substituents in a benzene derivative occupy the 1st and 3rd positions, it is called the meta position. Para indicates that two substituents are at the 1st and 4th positions; for example, when two substituents in a benzene derivative occupy the 1st and 4th positions, it is called the para position.

[0018] Furthermore, the term "substituted" in the phrase "substituted or unsubstituted" means that a hydrogen atom in a functional group is replaced with another atom or another functional group (i.e., a substituent), and includes substitution with a group to which two or more substituents are bonded. For example, a "substituent to which two or more substituents are bonded" can be pyridine-triazine. That is, pyridine-triazine can be interpreted as one heteroaryl substituent or as a substituent to which two heteroaryl substituents are bonded. In the present disclosure, the substituents of the substituted alkyl, substituted aryl, substituted arylene, substituted heteroaryl, substituted heteroarylene, substituted cycloalkyl, substituted heterocycloalkyl, substituted trialkylsilyl, substituted dialkylarylsilyl, substituted alkyldiarylsilyl, and substituted triarylsilyl are each independently deuterium; halogen; cyano; carboxyl; nitro; hydroxyl; phosphine oxide; (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; or (3- to 30-membered) heteroaryl that is unsubstituted or substituted with (C6-C30) aryl. ;(C6-C30)aryl unsubstituted or substituted with at least one of (C1-C30)alkyl, (3-30 membered)heteroaryl and di(C6-C30)arylamino; 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-(C2-C30) alkenylamino; mono- or di-(C6-C30) arylamino; mono- or di(3-30 membered) heteroarylamino; (C1-C30) alkyl(C2-C30) alkenylamino; (C1-C30) alkyl(C6-C30) arylamino; (C1-C30) alkyl(3-30 membered) heteroarylamino; (C2-C30) alkenyl(C6-C30) arylamino;At least one selected from the group consisting of (C2-C30)alkenyl(3-30 membered)heteroarylamino; (C6-C30)aryl(3-30 membered)heteroarylamino; (C1-C30)alkylcarbonyl; (C1-C30)alkoxycarbonyl; (C6-C30)arylcarbonyl; (C6-C30)arylphosphine; di(C6-C30)arylboronyl; di(C1-C30)alkylboronyl; (C1-C30)alkyl(C6-C30)arylboronyl; (C6-C30)aryl(C1-C30)alkyl; and (C1-C30)alkyl(C6-C30)aryl. According to one embodiment of the present disclosure, the substituents are each independently at least one selected from the group consisting of (C1-C20) alkyl; (5-25 membered) heteroaryl unsubstituted or substituted with (C6-C18) aryl; and (C6-C25) aryl unsubstituted or substituted with at least one of (C1-C30) alkyl and (5-25 membered) heteroaryl. According to another embodiment of the present disclosure, the substituents are each independently at least one selected from the group consisting of (C1-C10) alkyl, (5-25 membered) heteroaryl, and (C6-C25) aryl. For example, the substituents may each independently be at least one selected from the group consisting of methyl, phenyl, and naphthyl.

[0019] In the formula of the present disclosure, when adjacent substituents are bonded to each other to form a ring, the ring may be a substituted or unsubstituted monocyclic or polycyclic (3 to 30-membered) aliphatic or aromatic ring, or a combination thereof. Furthermore, the formed ring may contain at least one heteroatom selected from N, O, and S. The ring may preferably be a substituted or unsubstituted monocyclic or polycyclic (3 to 26-membered) aliphatic or aromatic ring, or a combination thereof, more preferably an unsubstituted monocyclic or polycyclic (5 to 15-membered) aromatic ring. Additionally, the ring may form a spiro ring together with the skeletal structure. For example, the 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, a substituted or unsubstituted carbazole ring, or the like.

[0020] In the formulae of the present disclosure, heteroaryl(ylene)s and heterocycloalkyls may each independently contain at least one heteroatom selected from B, N, O, S, Si, and P. Furthermore, 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 (5-30 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) 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.

[0021] Compounds represented by formula 1 are described in further detail below.

[0022] In Formula 1, Ar1 and Ar2 each independently represent hydrogen, deuterium, halogen, cyano, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (3-7 membered) heterocycloalkyl, substituted or unsubstituted (C6-C30) aryl, or substituted or unsubstituted (3-30 membered) heteroaryl, or Ar1 and Ar2 may be bonded to each other to form a fused ring. Ar1 and Ar2 may be the same or different. According to one embodiment of the present disclosure, Ar1 and Ar2 each independently represent substituted or unsubstituted (C1-C20) alkyl or substituted or unsubstituted (C6-C25) aryl, or Ar1 and Ar2 may be bonded to each other to form a fused ring. According to another embodiment of the present disclosure, Ar1 and Ar2 each independently represent an unsubstituted (C1-C10) alkyl or an unsubstituted (C6-C25) aryl, or Ar1 and Ar2 may be bonded to each other to form a fused ring. For example, Ar1 and Ar2 each independently may be methyl or phenyl, or they may be bonded to each other to form a fluorene ring.

[0023] In Formula 1, R1 to R6 each independently represent hydrogen, deuterium, halogen, cyano, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (3-7 membered) heterocycloalkyl, substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (3-30 membered) heteroaryl, substituted or unsubstituted tri(C1-C30) alkylsilyl, substituted or unsubstituted di(C1-C30) alkyl(C6-C30) arylsilyl, substituted or unsubstituted (C1-C30) alkyldi(C6-C30) arylsilyl, or substituted or unsubstituted tri(C6-C30) arylsilyl. According to one embodiment of the present disclosure, R1 to R6 each independently represent hydrogen, deuterium, substituted or unsubstituted (C6-C25) aryl, or substituted or unsubstituted (5-25 membered) heteroaryl. According to another embodiment of the present disclosure, R to R Each of R1 to R6 is independently hydrogen or unsubstituted (C6-C18)aryl. For example, R1 to R6 can be independently hydrogen or phenyl.

[0024] In formula 1, R7 to R 10 are each independently hydrogen, deuterium, halogen, cyano, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (3-7 membered) heterocycloalkyl, substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (3-30 membered) heteroaryl, substituted or unsubstituted tri(C1-C30) alkylsilyl, substituted or unsubstituted di(C1-C30) alkyl(C6-C30) arylsilyl, substituted or unsubstituted (C1-C 30) Alkyldi(C6-C30)arylsilyl, substituted or unsubstituted tri(C6-C30)arylsilyl, or [ka] represents R7~R 10 At least one of [ka] and * represents the position of attachment to the benzofluorene. According to one embodiment of the present disclosure, R to R 10 are each independently hydrogen, deuterium, a substituted or unsubstituted (C1-C10) alkyl, a substituted or unsubstituted (C6-C25) aryl, a substituted or unsubstituted (5-25 membered) heteroaryl, or [ka] According to another embodiment of the present disclosure, R7 to R 10 One of the following is [ka] For example, R7~R 10 One of the following is [ka] and another may be hydrogen.

[0025] L1 is a single bond, a substituted or unsubstituted (C6-C30) arylene, or a substituted or unsubstituted (3-30 membered) heteroarylene. According to one embodiment of the present disclosure, L1 is a single bond or a substituted or unsubstituted (C6-C25) arylene. According to another embodiment of the present disclosure, L1 is a single bond or a substituted or unsubstituted (C6-C18) arylene. For example, L1 can be a single bond, phenylene, or naphthylene.

[0026] Ar3 and Ar4 each independently represent hydrogen, deuterium, halogen, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (3-7 membered) heterocycloalkyl, substituted or unsubstituted (C6-C30) aryl, or substituted or unsubstituted (3-30 membered) heteroaryl, or Ar3 and Ar4 may be bonded to each other to form a fused ring. Ar3 and Ar4 may be the same or different. According to one embodiment of the present disclosure, Ar3 and Ar4 each independently represent substituted or unsubstituted (C6-C25) aryl or substituted or unsubstituted (5-25 membered) heteroaryl. According to another embodiment of the present disclosure, Ar3 and Ar4 each independently represent (C6-C25) aryl that is unsubstituted or substituted with at least one (C1-C10) alkyl, or (5-25 membered) heteroaryl that is unsubstituted or substituted with at least one (C6-C18) aryl. For example, Ar3 and Ar4 can each independently be phenyl, biphenyl, naphthylphenyl, phenylnaphthyl, terphenyl, dimethylfluorenyl, diphenylfluorenyl, 9,9'-spirobifluorenyl, dibenzothiophenyl, dibenzofuranyl, or carbazolyl substituted with phenyl.

[0027] Formula 1 is the following formulas 1-1 to 1-4: [ka] (In the formula, Ar1 to Ar4, R1 to R6, and L1 are as defined in Formula 1. It can be represented by at least one of:

[0028] In formulas 1-1 to 1-4, R to R 10are each independently hydrogen, deuterium, halogen, cyano, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (3-7 membered) heterocycloalkyl, substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (3-30 membered) heteroaryl, substituted or unsubstituted tri(C1-C30) alkylsilyl, substituted or unsubstituted di(C1-C30) alkyl(C6-C30) arylsilyl, substituted or unsubstituted (C1-C30) alkyldi(C6-C30) arylsilyl, or substituted or unsubstituted tri(C6-C30) arylsilyl. 10 are each independently hydrogen, deuterium, substituted or unsubstituted (C1-C20) alkyl, substituted or unsubstituted (C6-C25) aryl, or substituted or unsubstituted (5-25 membered) heteroaryl. 10 are each independently hydrogen, deuterium, substituted or unsubstituted (C1-C10) alkyl, substituted or unsubstituted (C6-C18) aryl, or substituted or unsubstituted (5-20 membered) heteroaryl. For example, R7 to R 10 can be hydrogen.

[0029] The compound represented by Formula 1 can be at least one selected from, but is not limited to, the following compounds: [ka] [ka] [ka] [ka] [ka]

[0030] The organic electroluminescent compound of the present disclosure can be prepared by synthetic methods known to those skilled in the art.For example, but not limited to, the organic electroluminescent compound of the present disclosure can be synthesized as shown in the following reaction schemes 1 and 2.The organic electroluminescent compound of the present disclosure can be synthesized in large quantities by using the following synthetic method, because starting materials are easily available and can minimize the generation of isomers. [Reaction Scheme 1] [ka] [Reaction Scheme 2] [ka]

[0031] In Reaction Scheme 1, "1" represents Suzuki reaction, "2" represents intramolecular cyclization, "3" represents ketone reduction, "4" represents methylation, "2-1" represents Grignard reaction, "2-2" represents intramolecular cyclization, "3-1" represents lithiation, and "3-2" represents intramolecular cyclization. In Reaction Schemes 1 and 2, L1, Ar3, and Ar4 are as defined in Formula 1, a is an integer of 1 to 4, and b is an integer of 1 to 5. When a and b are each 2 or greater, each R 11 and each R 21 may be the same or different from each other, R 11 and R 21 The definitions of are each independently the same as the definitions of R1 to R6 in formula 1.

[0032] Although exemplary synthetic examples of compounds represented by Formula 1 have been described above, those skilled in the art will readily understand that all of them are based on Buchwald-Hartwig cross-coupling reactions, N-arylation reactions, H-mont-mediated etherification reactions, Miyaura borylation reactions, Suzuki cross-coupling reactions, intramolecular acid-induced cyclization reactions, Pd(II)-catalyzed oxidative cyclization reactions, Grignard reactions, Heck reactions, cyclodehydration reactions, SN1 substitution reactions, SN2 substitution reactions, phosphine-mediated reductive cyclization reactions, etc., and that the above reactions will proceed even when substituents defined in Formula 1 above but not specified in the specific synthetic examples are attached.

[0033] The dopant that can be used in combination with the compound of the present disclosure can be at least one phosphorescent or fluorescent dopant, preferably a phosphorescent dopant.The phosphorescent dopant can be, but is not limited to, a complex compound of a metal atom selected from iridium (Ir), osmium (Os), copper (Cu) and platinum (Pt), and in some cases, preferably an ortho-metallated complex compound of a metal atom selected from iridium (Ir), osmium (Os), copper (Cu) and platinum (Pt), and in some cases, more preferably an ortho-metallated iridium complex compound.

[0034] The organic electroluminescent compound represented by Formula 1 of the present disclosure can be included in at least one layer constituting an organic electroluminescent device, for example, at least one layer selected from a hole injection layer, a hole transport layer, a hole auxiliary layer, a light-emitting auxiliary layer, a light-emitting 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. Each layer can be further composed of multiple layers. Furthermore, the compound represented by Formula 1 of the present disclosure can be included in at least one layer of a hole injection layer, a hole transport layer, a hole auxiliary layer, a light-emitting auxiliary layer, and an electron transport layer, but is not limited thereto.

[0035] At least one of the organic electroluminescent materials of the present disclosure, such as hole injection materials, hole transport materials, hole assist materials, light-emitting assist materials, electron blocking materials, light-emitting materials, electron buffer materials, hole blocking materials, electron transport materials, and electron injection materials, can include a compound represented by Formula 1. The material can be a hole transport zone material, and the hole transport zone material can be at least one of a hole injection material, a hole transport material, a hole assist material, a light-emitting assist material, and an electron blocking material. The hole transport zone material can consist solely of the compound represented by Formula 1, or it can also include conventional materials contained in organic electroluminescent materials. When two or more types of materials are contained in a layer, the layer can be formed by mixed deposition or simultaneously and separately by co-deposition. When using the high refractive index material of the present disclosure, the device thickness can be reduced, thereby facilitating material reduction and improved process productivity. In particular, because red-emitting organic electroluminescent devices are generally thicker than blue- or green-emitting devices, using the high refractive index materials of the present disclosure for red-emitting devices can reduce their thickness, thereby significantly improving the manufacturing efficiency of the devices.

[0036] 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. One of the first and second electrodes can be an anode, and the other can be a cathode. The organic layer includes at least one light-emitting layer and can further include at least one layer selected from a hole-injection layer, a hole-transport layer, a hole-assisting layer, a light-emitting assisting layer, an electron-transport layer, an electron buffer layer, an electron-injection layer, an intermediate layer, a hole-blocking layer, and an electron-blocking layer.

[0037] The present disclosure may include a hole-transporting zone between the anode and the light-emitting layer, which may include at least one of a hole-injection layer, a hole-transporting layer, a hole-assisting layer, a light-emitting assisting layer, and an electron-blocking layer. The hole-injection layer, the hole-transporting layer, the hole-assisting layer, the light-emitting assisting layer, and the electron-blocking layer may each be a single layer or a multilayer structure in which two or more layers are stacked. For the hole-injection layer, multiple layers may be used to lower the hole-injection barrier (or hole-injection voltage) from the anode to the hole-transporting layer or the electron-blocking layer, and two compounds may be used simultaneously in each layer. An electron-blocking layer may be disposed between the hole-transporting layer (or hole-injection layer) and the light-emitting layer, which may prevent electrons from overflowing from the light-emitting layer and confine excitons in the light-emitting layer to prevent light leakage.

[0038] In addition, the hole transport zone may include a p-type doped hole injection layer, a hole transport layer, and a light-emitting auxiliary layer. In this specification, a p-type doped hole injection layer refers to a hole injection layer doped with a p-type dopant. A p-type dopant is a material that provides p-type semiconductor properties. The p-type semiconductor properties refer to the property of accepting or transporting holes at the highest occupied molecular orbital (HOMO) energy level, i.e., the property of a material having high hole conductivity.

[0039] The organic electroluminescent device according to the present disclosure may include a compound represented by Formula 1, or may further include conventional materials included in organic electroluminescent devices. The organic electroluminescent device according to the present disclosure may include a compound represented by Formula 1 in a layer of a hole transport zone. For example, the organic electroluminescent device according to the present disclosure may include a compound of the present disclosure in at least one of a hole injection layer, a hole transport layer, a hole auxiliary layer, a light-emitting auxiliary layer, and an electron blocking layer.

[0040] Organic electroluminescent devices are classified into bottom-emitting devices and top-emitting devices according to their light-emitting structures. Specifically, bottom-emitting devices have a structure in which most of the light is directed toward the thin film transistor (TFT) of the organic electroluminescent device, while top-emitting devices have a structure in which most of the light is output from the opposite side of the thin film transistor of the organic electroluminescent device. Preferably, the organic electroluminescent device of the present disclosure can be applied to a top-emitting device. However, the organic electroluminescent device of the present disclosure is not limited thereto and can also be applied to a bottom-emitting device.

[0041] The present disclosure provides an organic electroluminescent device that is advantageous in process, by using materials that exhibit high refractive index, and can achieve the desired CIE 1931 color coordinates while optimizing the resonance phenomenon at low thicknesses.

[0042] The present disclosure also provides a display system by using the compound represented by Formula 1. That is, a display system or a lighting system can be manufactured by using the compound of the present disclosure. Specifically, the compound of the present disclosure can be used to manufacture a display system, for example, a display system for a smartphone, tablet, notebook, PC, TV, or automobile, or a lighting system, for example, an outdoor or indoor lighting system.

[0043] In the following, in order to understand the present disclosure in detail, the preparation methods of the compounds of the present disclosure and their properties will be described with reference to the representative compounds of the present disclosure. However, the present disclosure is not limited to the following examples. [Example]

[0044] Example 1: Preparation of Compound C-28 [ka] 1) Synthesis of Compound 1-1 Ethyl 7-bromo-3-hydroxy-2-naphthoate (100 g, 338.8 mmol) and 1,700 mL of N,N-dimethylformamide were placed in a reaction vessel, and sodium hydride (20.3 g) was slowly added at 0 °C. After stirring for 30 minutes, perfluorobutanesulfonyl fluoride (72 mL, 406.6 mmol) was added and the mixture was stirred at room temperature for 4 hours. After the reaction was complete, methanol was added to the mixture, and the mixture was poured into 2,000 mL of water to form a solid. The resulting solid was filtered under reduced pressure and washed with methanol to obtain compound 1-1 (157 g, yield: 92%).

[0045] 2) Synthesis of Compound 1-2 Compound 1-1 (157.0 g, 271.9 mmol), phenylboronic acid (33.1 g, 271.9 mmol), tetrakis(triphenylphosphine)palladium(0) (9.45 g, 8.157 mmol), sodium carbonate (72 g, 679.75 mmol), 1,350 mL of tetrahydrofuran, and 340 mL of water were added to a reaction vessel and stirred at 100 °C for 4 hours. After the reaction was completed, the mixture was washed with distilled water, and the organic layer was extracted with ethyl acetate. The organic layer was dried over magnesium sulfate, and the solvent was removed using a rotary evaporator. Compound 1-2 (52 g, yield: 53%) was then purified by column chromatography.

[0046] 3) Synthesis of Compounds 1-3 Compound 1-2 (52 g, 146.38 mmol) and 585 mL of methanesulfonic acid were added to a reaction vessel and stirred at 60° C. for 5 hours. After the reaction was completed, the stirred mixture was poured into 1,000 mL of water to form a solid. The resulting solid was filtered under reduced pressure and washed with methanol to obtain compound 1-3 (41.4 g, yield: 92%).

[0047] 4) Synthesis of Compounds 1-4 Phosphoric acid (36 mL, 214.6 mmol), iodine (17.7 g, 69.63 mmol), and acetic acid (330 mL) were added to a reaction vessel and stirred at 160 °C for 10 minutes. Compound 1-3 (41.4 g, 133.91 mmol) was dissolved in 340 mL of acetic acid and then added to the stirred mixture and stirred for 2 hours. After the reaction was completed, the mixture was poured into 1,000 mL of water to form a solid. The resulting solid was filtered under reduced pressure and washed with methanol to obtain compound 1-4 (32.5 g, yield: 82%).

[0048] 5) Synthesis of Compounds 1-5 Compound 1-4 (32.5 g, 110.1 mmol), potassium iodide (1.83 g, 11.01 mmol), potassium hydroxide (30.89 g, 550.5 mmol), triethylbenzylammonium chloride (1.25 g, 5.505 mmol), 550 mL of dimethyl sulfoxide, and 55 mL of water were placed in a reaction vessel and stirred for 1 hour. Methyl iodide was added and stirred at room temperature for 24 hours. After the reaction was complete, the mixture was washed with distilled water, and the organic layer was extracted with dichloromethane. The organic layer was dried over magnesium sulfate, and the solvent was removed using a rotary evaporator. Compound 1-5 (20 g, yield: 56%) was then purified by column chromatography.

[0049] 6) Synthesis of compound C-28 Compound 1-5 (3.0 g, 9.28 mmol), N-([1,1'-biphenyl]-2-yl)-9,9'-dimethyl-9H-fluoren-2-amine (2.8 g, 7.73 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.35 g, 0.39 mmol), tri-tert-butylphosphine (0.4 mL, 0.77 mmol), sodium tert-butoxide (1.1 g, 11.6 mmol), and 40 mL of toluene were added to a reaction vessel and stirred under reflux for 1 h. After the reaction mixture was cooled to room temperature, the solid was filtered and washed with ethyl acetate. The filtrate was distilled under reduced pressure and purified by column chromatography to give compound C-28 (1.9 g, 34% yield).

[0050] [Table 1]

[0051] Example 2: Preparation of Compound C-22 [ka] Compound 1-5 (3.0 g, 9.28 mmol), 9,9'-dimethyl-N-phenyl-9H-fluoren-2-amine (2.9 g, 10.21 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.35 g, 0.39 mmol), tri-tert-butylphosphine (0.4 mL, 0.77 mmol), sodium tert-butoxide (1.1 g, 11.6 mmol), and 40 mL of toluene were added to a reaction vessel and stirred under reflux for 1 h. After the reaction mixture was cooled to room temperature, the solid was filtered and washed with ethyl acetate. The filtrate was distilled under reduced pressure and purified by column chromatography to give compound C-22 (2.4 g, yield: 49%).

[0052] [Table 2]

[0053] Example 3: Preparation of Compound C-18 [ka] Compound 1-5 (3.0 g, 9.28 mmol), di([1,1'-biphenyl]-4-yl)amine (3.3 g, 10.21 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.35 g, 0.39 mmol), tri-tert-butylphosphine (0.4 mL, 0.77 mmol), sodium tert-butoxide (1.1 g, 11.6 mmol), and 40 mL of toluene were added to a reaction vessel and stirred under reflux for 1 h. After the reaction mixture was cooled to room temperature, the solid was filtered and washed with ethyl acetate. The filtrate was distilled under reduced pressure and purified by column chromatography to give compound C-18 (1.4 g, yield: 26%).

[0054] [Table 3]

[0055] Example 4: Preparation of Compound C-19 [ka] Compound 1-5 (3.0 g, 9.28 mmol), 4-(naphthalen-2-yl)-N-phenylaniline (2.7 g, 9.28 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.4 g, 0.46 mmol), tri-tert-butylphosphine (0.5 mL, 0.93 mmol), sodium tert-butoxide (1.3 g, 13.92 mmol), and 46 mL of toluene were added to a reaction vessel and stirred under reflux for 1 hour. After the reaction mixture was cooled to room temperature, the solid was filtered and washed with ethyl acetate. The filtrate was distilled under reduced pressure and purified by column chromatography to give compound C-19 (3.1 g, yield: 62%).

[0056] [Table 4]

[0057] Example 5: Preparation of Compound C-31 [ka] Compound 1-5 (3.0 g, 9.28 mmol), N-([1,1'-biphenyl]-4-yl)-9,9'-dimethyl-9H-fluoren-3-amine (3.4 g, 9.28 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.4 g, 0.46 mmol), tri-tert-butylphosphine (0.5 mL, 0.93 mmol), sodium tert-butoxide (1.3 g, 13.92 mmol), and 46 mL of toluene were added to a reaction vessel and stirred under reflux for 1 h. After the reaction mixture was cooled to room temperature, the solid was filtered and washed with ethyl acetate. The filtrate was distilled under reduced pressure and purified by column chromatography to give compound C-31 (4.1 g, yield: 73%).

[0058] [Table 5]

[0059] Example 6: Preparation of Compound C-103 [ka] Compound 1-5 (2.0 g, 6.19 mmol), N-([1,1'-biphenyl]-4-yl)-{1,1'-biphenyl}-2-amine (1.8 g, 5.63 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.3 g, 0.28 mmol), tri-tert-butylphosphine (0.3 mL, 0.57 mmol), sodium tert-butoxide (0.8 g, 8.45 mmol), and 28 mL of toluene were added to a reaction vessel and stirred under reflux for 1 h. After the reaction mixture was cooled to room temperature, the solid was filtered and washed with ethyl acetate. The filtrate was distilled under reduced pressure and purified by column chromatography to give compound C-103 (1.7 g, 53% yield).

[0060] [Table 6]

[0061] Example 7: Preparation of Compound C-104 [ka] Compound 1-5 (4.7 g, 12.99 mmol), N-([1,1'-biphenyl]-4-yl)-{1,1':3',1"-terphenyl}-4'-amine (5.2 g, 12.99 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.6 g, 0.65 mmol), tri-tert-butylphosphine (0.6 mL, 1.30 mmol), sodium tert-butoxide (1.9 g, 19.49 mmol), and 65 mL of toluene were added to a reaction vessel and stirred under reflux for 1 h. After the reaction mixture was cooled to room temperature, the solid was filtered and washed with ethyl acetate. The filtrate was distilled under reduced pressure and purified by column chromatography to give compound C-104 (2.7 g, 33% yield).

[0062] [Table 7]

[0063] Example 8: Preparation of Compound C-27 [ka] Compound 1-5 (3.0 g, 9.28 mmol), N,9-diphenyl-9H-carbazol-2-amine (3.1 g, 9.28 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.4 g, 0.46 mmol), tri-tert-butylphosphine (0.5 mL, 0.93 mmol), sodium tert-butoxide (1.3 g, 13.92 mmol), and 47 mL of toluene were added to a reaction vessel and stirred under reflux for 1 h. After the reaction mixture was cooled to room temperature, the solid was filtered and washed with ethyl acetate. The filtrate was distilled under reduced pressure and purified by column chromatography to give compound C-27 (3.0 g, yield: 56%).

[0064] [Table 8]

[0065] Example 9: Preparation of Compound C-105 [ka] Compound 1-5 (5.62 g, 17.38 mmol), N-([1,1'-biphenyl]-4-yl)-{1,1':3',1"-terphenyl}-5'-amine (7.6 g, 19.12 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.8 g, 0.87 mmol), tri-tert-butylphosphine (0.9 mL, 1.74 mmol), sodium tert-butoxide (2.5 g, 26.07 mmol), and 87 mL of toluene were added to a reaction vessel and stirred under reflux for 1 h. After the reaction mixture was cooled to room temperature, the solid was filtered and washed with ethyl acetate. The filtrate was distilled under reduced pressure and purified by column chromatography to obtain compound C-105 (7.5 g, yield: 67%).

[0066] [Table 9]

[0067] Example 10: Preparation of Compound C-106 [ka] Compound 1-5 (4.0 g, 12.38 mmol), N-(4-[naphthalen-2-yl]phenyl)-[1,1'-biphenyl]-4-amine (5.05 g, 13.61 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.6 g, 0.62 mmol), tri-tert-butylphosphine (0.6 mL, 1.24 mmol), sodium tert-butoxide (1.8 g, 18.57 mmol), and 62 mL of toluene were added to a reaction vessel and stirred under reflux for 1 hour. After the reaction mixture was cooled to room temperature, the solid was filtered and washed with ethyl acetate. The filtrate was distilled under reduced pressure and purified by column chromatography to give compound C-106 (3.8 g, 50% yield).

[0068] [Table 10]

[0069] Example 11: Preparation of Compound C-107 [ka] Compound 1-5 (3.5 g, 10.82 mmol), N-([1,1'-biphenyl]-4-yl)-9,9'-dimethyl-9H-fluoren-2-amine (4.3 g, 11.91 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.5 g, 0.54 mmol), tri-tert-butylphosphine (0.55 mL, 1.08 mmol), sodium tert-butoxide (1.6 g, 16.23 mmol), and 54 mL of toluene were added to a reaction vessel and stirred under reflux for 1 h. After the reaction mixture was cooled to room temperature, the solid was filtered and washed with ethyl acetate. The filtrate was distilled under reduced pressure and purified by column chromatography to give compound C-107 (5.4 g, 82% yield).

[0070] [Table 11]

[0071] Example 12: Preparation of Compound C-108 [ka] Compound 1-5 (3.5 g, 10.82 mmol), N-([1,1'-biphenyl]-2-yl)dibenzo[b,d]furan-2-amine (4.0 g, 11.91 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.5 g, 0.54 mmol), tri-tert-butylphosphine (0.55 mL, 1.08 mmol), sodium tert-butoxide (1.6 g, 16.23 mmol), and 54 mL of toluene were added to a reaction vessel and stirred under reflux for 1 h. After the reaction mixture was cooled to room temperature, the solid was filtered and washed with ethyl acetate. The filtrate was distilled under reduced pressure and purified by column chromatography to give compound C-108 (2.8 g, 45% yield).

[0072] [Table 12]

[0073] Example 13: Preparation of Compound C-43 [ka] 1) Synthesis of Compounds 1-6 Bromobenzene (14 mL, 132.6 mmol) and 221 mL of tetrahydrofuran were placed in a reaction vessel and stirred at -78 °C. After 10 minutes, n-butyllithium (53 mL, 132.6 mmol) was slowly added and stirred. After 1 hour, compound 1-2 (15.7 g, 44.2 mmol) was added and stirred at room temperature for 18 hours. After the reaction was complete, the mixture was washed with 200 mL of water and 200 mL of ammonium chloride, extracted with ethyl acetate, dried over magnesium sulfate, and then the solvent was removed using a rotary evaporator to give compound 1-6 (24.8 g, yield: 120%).

[0074] 2) Synthesis of Compounds 1-7 Compound 1-6 (24.8 g, 53.4 mmol), hydrochloric acid (22.3 mL), and acetic acid (223 mL) were placed in a reaction vessel and stirred at 160° C. After 18 hours, the resulting solid was filtered under reduced pressure, washed with water, aqueous sodium hydroxide solution, methanol, and hexane, and then purified by column chromatography to obtain compound 1-7 (12.0 g, yield: 50%).

[0075] 2) Synthesis of Compound C-43 Compound 1-7 (4.0 g, 8.95 mmol), bis(4-biphenyl)amine (2.6 g, 8.14 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.37 g, 0.41 mmol), tri-tert-butylphosphine (0.4 mL, 0.81 mmol), sodium tert-butoxide (1.2 g, 12.2 mmol), and 40 mL of toluene were placed in a reaction vessel and stirred under reflux for 1 h. After the reaction mixture was cooled to room temperature, the solid was filtered and washed with ethyl acetate. The filtrate was distilled under reduced pressure and purified by column chromatography to give compound C-43 (4.3 g, 70% yield).

[0076] [Table 13]

[0077] Example 14: Preparation of Compound C-47 [ka] Compound 1-7 (4.0 g, 8.95 mmol), 9,9-dimethyl-N-phenyl-9H-fluoren-2-amine (2.3 g, 8.14 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.4 g, 0.41 mmol), tri-tert-butylphosphine (0.4 mL, 0.81 mmol), sodium tert-butoxide (1.2 g, 12.21 mmol), and 40 mL of toluene were added to a reaction vessel and stirred under reflux for 1 h. After the reaction mixture was cooled to room temperature, the solid was filtered and washed with ethyl acetate. The filtrate was distilled under reduced pressure and purified by column chromatography to give compound C-47 (3.9 g, 74% yield).

[0078] [Table 14]

[0079] Example 15: Preparation of Compound C-101 [ka] Compound 1-7 (4.0 g, 8.95 mmol), N-([1,1'-biphenyl]-4-yl)-9,9'-dimethyl-9H-fluoren-2-amine (3.2 g, 8.95 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.4 g, 0.45 mmol), tri-tert-butylphosphine (0.4 mL, 0.90 mmol), sodium tert-butoxide (1.3 g, 13.43 mmol), and 45 mL of toluene were added to a reaction vessel and stirred under reflux for 1 h. After the reaction mixture was cooled to room temperature, the solid was filtered and washed with ethyl acetate. The filtrate was distilled under reduced pressure and purified by column chromatography to give compound C-101 (3.9 g, 74% yield).

[0080] [Table 15]

[0081] Example 16: Preparation of Compound C-53 [ka] Compound 1-7 (6.0 g, 13.45 mmol), N-([1,1'-biphenyl]-2-yl)-9,9'-dimethyl-9H-fluoren-2-amine (5.8 g, 16.14 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.62 g, 0.67 mmol), tri-tert-butylphosphine (0.66 mL, 1.35 mmol), sodium tert-butoxide (2.6 g, 26.9 mmol), and 70 mL of toluene were added to a reaction vessel and stirred under reflux for 4 hours. After the reaction mixture was cooled to room temperature, the solid was filtered and washed with ethyl acetate. The filtrate was distilled under reduced pressure and purified by column chromatography to give compound C-53 (5.4 g, 55% yield).

[0082] [Table 16]

[0083] Example 17: Preparation of Compound C-102 [ka] Compound 1-7 (6.0 g, 13.45 mmol), N-([1,1'-biphenyl]-4-yl)-[1,1'-biphenyl]-2-amine (5.2 g, 16.14 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.62 g, 0.67 mmol), tri-tert-butylphosphine (0.66 mL, 1.35 mmol), sodium tert-butoxide (2.6 g, 26.9 mmol), and 70 mL of toluene were added to a reaction vessel and stirred under reflux for 4 hours. After the reaction mixture was cooled to room temperature, the solid was filtered and washed with ethyl acetate. The filtrate was distilled under reduced pressure and purified by column chromatography to give compound C-102 (5.0 g, yield: 54%).

[0084] [Table 17]

[0085] Example 18: Preparation of Compound C-109 [ka] Compound A (3.0 g, 9.28 mmol), di([1,1'-biphenyl]-4-yl)amine (3.3 g, 10.21 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.35 g, 0.39 mmol), tri-tert-butylphosphine (0.4 mL, 0.77 mmol), sodium tert-butoxide (1.1 g, 11.6 mmol), and 40 mL of toluene were placed in a reaction vessel and stirred under reflux for 1 hour. After the reaction mixture was cooled to room temperature, the solid was filtered and washed with ethyl acetate. The filtrate was distilled under reduced pressure and purified by column chromatography to give compound C-109 (1.5 g, yield: 26%).

[0086] [Table 18]

[0087] In the following, for the detailed understanding of the present disclosure, the method for manufacturing the organic electroluminescent device that comprises the compound of the present disclosure and the light-emitting properties are described.The following examples are merely for the detailed understanding of the present disclosure, and the present disclosure is not limited thereto.

[0088] Device Example 1: Fabrication of an OLED using compounds according to the present disclosure An OLED was fabricated using the organic electroluminescent compound according to the present disclosure. First, a transparent electrode indium tin oxide (ITO) thin film (10 Ω / sq) obtained from OLED glass (Geomatec Co., Ltd., Japan) was ultrasonically cleaned in acetone, ethanol, and distilled water, and then stored in isopropanol. The vacuum in the chamber was adjusted to 10 -6After degassing to a pressure of 1000 torr, the ITO substrate was attached to a substrate holder in a vacuum evaporation system. Compound HT-1 was placed in one cell of the vacuum evaporation system, and compound HI-1 was placed in another cell. Compound HI-1 was doped into the vacuum evaporation system at a pressure of 3 wt % based on the total weight of compounds HT-1 and HI-1, allowing the two materials to evaporate at different rates to deposit a 10-nm-thick hole injection layer. Compound HT-1 was then introduced into a cell of the vacuum evaporation system, and a current was passed through the cell to cause evaporation, thereby depositing a 90-nm-thick first hole transport layer. Compound C-19, according to the present disclosure, was then introduced into another cell of the vacuum evaporation system, and a current was passed through the cell to cause evaporation, thereby depositing a 60-nm-thick second hole transport layer on the first hole transport layer. After forming the hole injection layer and hole transport layer, an emitting layer was formed thereon as follows: Compound RH-1 was introduced into one cell of the vacuum evaporation system as the emitting layer host, and compound RD was introduced into another cell as the dopant. The two materials were evaporated to deposit a 40-nm-thick light-emitting layer on the second hole-transporting layer by doping the dopant at 2 wt % based on the total amount of the host and dopant. Subsequently, Compound ET and Compound EI were evaporated at a 1:1 ratio in two different cells to deposit a 35-nm-thick electron-transporting layer on the light-emitting layer.

[0089] The OLED was fabricated by depositing the compound EI as an electron injection layer to a thickness of 2 nm, and then depositing an Al cathode to a thickness of 80 nm using another vacuum deposition system.

[0090] Comparative Example 1: OLED Fabrication Using Conventional Compounds An OLED was fabricated in the same manner as in Device Example 1, except that Compound A was used instead of Compound C-19.

[0091] Refractive index measurement method The refractive index of the compound used in the second hole transport layer of the device examples and comparative examples was measured by the following method. The compound whose refractive index was to be measured was placed in a cell of a vacuum deposition apparatus, and the degree of vacuum in the chamber was 10 -6A 30 nm thick sample was fabricated on a silicon wafer substrate by evacuating the cell to 1000 psig (2000 mbar) and applying current to the cell for evaporation. The refractive index was measured using an ellipsometer. Specifically, the refractive index was measured at 620 nm at an incident angle of 60° using a HORIBA UVISEL at wavelengths from 350 nm to 800 nm.

[0092] 1,000 cd / m of the OLEDs fabricated in Device Example 1 and Comparative Example 1 2 The measurement results of the driving voltage, power efficiency and color coordinates based on the luminance of the device, and the measurement results of the refractive index of the compounds used in Device Example 1 and Comparative Example 1 are shown in Table 1 below.

[0093] [Table 19]

[0094] Device Examples 2-1 to 2-3: Fabrication of OLEDs using compounds according to the present disclosure An OLED was fabricated in the same manner as in Device Example 1, except that the compound shown in Table 2 below was used instead of Compound C-19 as the compound in the second hole transport layer, and Compound RH-2 was used instead of Compound RH-1 as the host in the light-emitting layer.

[0095] Comparative Examples 2-1 and 2-2: OLED Fabrication Using Conventional Compounds An OLED was fabricated in the same manner as in Device Example 1, except that the compound shown in Table 2 below was used instead of Compound C-19 as the compound in the second hole transport layer, and Compound RH-2 was used instead of Compound RH-1 as the host in the light-emitting layer.

[0096] 1,000 cd / m of the OLEDs manufactured in Device Examples 2-1 to 2-3 and Comparative Examples 2-1 and 2-2 2 The measurement results of the drive voltage, power efficiency and color coordinates based on the luminance of the device, and the measurement results of the refractive index of the compounds used in Device Examples 2-1 to 2-3 and Comparative Examples 2-1 and 2-2 are shown in Table 2 below.

[0097] [Table 20]

[0098] According to the above results, the organic electroluminescent compound of the present disclosure has a higher refractive index than conventional compounds, which is expected to reduce the thickness of the device. In addition, it was confirmed that the device examples of the present disclosure can provide deep red organic electroluminescent devices with improved driving voltage and power efficiency, even when using a hole transport layer of the same thickness as the comparative example. This is understood to be because the higher the refractive index of the material, the slower the light transfer speed and the more molecules per unit volume, thereby improving the intermolecular electron hopping ability, thereby reducing the driving voltage of the organic electroluminescent device and saving power consumption.

[0099] The compounds used in the device examples and comparative examples are shown in Table 3 below.

[0100] [Table 21]

Claims

1. Formula 1 below: 【Chemical 1】 (In the formula, Ar １ and Ar ２ each independently represent a substituted or unsubstituted (C1-C30) alkyl or a substituted or unsubstituted (C6-C30) aryl, and the substituent of the substituted aryl is at least one selected from the group consisting of deuterium; halogen; cyano; (C1-C30) alkyl; (C3-C30) cycloalkyl; (3-30 membered) heteroaryl that is unsubstituted or substituted with at least one of (C6-C30) aryl; and (C6-C30) aryl that is unsubstituted or substituted with at least one of (C1-C30) alkyl, (3-30 membered) heteroaryl, and di(C6-C30) arylamino; R １ ~R ６ each independently represents hydrogen or deuterium; R ７ ~R １０ are each independently hydrogen, deuterium, halogen, cyano, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (3-7 membered) heterocycloalkyl, substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (3-30 membered) heteroaryl, or 【Chemistry 2】 represents, R ７ ~R １０ At least one of 【Chemistry 3】 provided that: L １ represents a single bond, a substituted or unsubstituted (C6 to C30) arylene, or a substituted or unsubstituted (3 to 30 membered) heteroarylene; Ar ３ and Ar ４ each independently represents a substituted or unsubstituted (C1-C30) alkyl, a substituted or unsubstituted (C3-C30) cycloalkyl, a substituted or unsubstituted (3- to 7-membered) heterocycloalkyl, a substituted or unsubstituted (C6-C30) aryl, or a substituted or unsubstituted (3- to 30-membered) heteroaryl; Ar ４ wherein the substituted or unsubstituted (C6-C30)aryl is selected from the group consisting of substituted or unsubstituted phenyl, deuterated or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted binaphthyl, substituted or unsubstituted phenylnaphthyl, substituted or unsubstituted naphthylphenyl, substituted or unsubstituted phenylterphenyl, substituted or unsubstituted phenylfluorenyl, substituted or unsubstituted diphenylfluorenyl, substituted or unsubstituted benzofluorenyl, substituted or unsubstituted dibenzofluorenyl, substituted or unsubstituted phenanthrenyl, substituted or unsubstituted phenylphenanthrenyl, substituted or unsubstituted anthracenyl, and substituted or unsubstituted spirobifluorenyl; and * indicates the position where it is bonded to benzofluorene.

1. An organic electroluminescent compound represented by the formula:

2. Formula 1 is the following formulas 1-1 to 1-4: 【Chemistry 4】 (In the formula, Ar １ ~Ar ４ , R １ ~R ６ and L １ is as defined in Equation 1, and R ７ ~R １０ each independently represents hydrogen, deuterium, halogen, cyano, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (3-7 membered) heterocycloalkyl, substituted or unsubstituted (C6-C30) aryl, or substituted or unsubstituted (3-30 membered) heteroaryl.

2. The organic luminescent compound of claim 1, wherein the organic luminescent compound is represented by at least one of:

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

4. The following compounds: 【Chemistry 5】 【Chemistry 6】 【Chemistry 7】 【Chemistry 8】 2. The organic luminescent compound according to claim 1, wherein the organic luminescent compound is at least one selected from:

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

6. 6. The organic electroluminescent material of claim 5, which is a material in a hole transport zone.

7. 6. The organic electroluminescent material according to claim 5, wherein the material of the hole transporting zone is at least one of a hole injection material, a hole transporting material, a hole assisting material, a light-emitting assisting material, and an electron blocking material.

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

9. 9. The organic electroluminescent device according to claim 8, wherein the organic electroluminescent compound is contained in a layer of a hole transport zone.

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