WO2020171630A1

WO2020171630A1 - Organic electroluminescent compound and organic electroluminescent device comprising the same

Info

Publication number: WO2020171630A1
Application number: PCT/KR2020/002478
Authority: WO
Inventors: Hyo-Soon Park; Jin-Ri HONG; Hyo-Jung Lee; Hyun-Ju Kang; Tae-Jun Han; Ye-Jin Jeon
Original assignee: Rohm and Haas Electronic Materials Korea Ltd
Current assignee: DuPont Specialty Materials Korea Ltd
Priority date: 2019-02-20
Filing date: 2020-02-20
Publication date: 2020-08-27
Anticipated expiration: 2021-08-20
Also published as: CN113454185A; KR102816266B1; KR20200101740A

Abstract

The present disclosure relates to an organic electroluminescent compound represented by formula 1, and an organic electroluminescent device comprising the same. It is possible to provide an organic electroluminescent device having improved driving voltage, luminous efficiency, lifespan characteristic, and/or power efficiency by comprising the organic electroluminescent compound of the present disclosure.

Description

ORGANIC ELECTROLUMINESCENT COMPOUND AND ORGANIC ELECTROLUMINESCENT DEVICE COMPRISING THE SAME

The present disclosure relates to an organic electroluminescent compound and an organic electroluminescent device comprising the same.

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

The most important factor determining luminous efficiency in an organic electroluminescent device is light-emitting materials. Until now, fluorescent materials have been widely used as light-emitting materials. However, in view of electroluminescent mechanisms, since phosphorescent light-emitting materials theoretically enhance luminous efficiency by four (4) times compared to fluorescent light-emitting materials, phosphorescent light-emitting materials have been widely researched. Iridium(III) complexes have been widely known as phosphorescent light-emitting materials, including bis(2-(2'-benzothienyl)-pyridinato-N,C-3')iridium(acetylacetonate) ((acac)Ir(btp)₂), tris(2-phenylpyridine)iridium (Ir(ppy)₃) and bis(4,6-difluorophenylpyridinato-N,C2)picolinato iridium (Firpic) as red-, green-, and blue-emitting materials, respectively.

At present, 4,4'-N,N'-dicarbazole-biphenyl (CBP) is the most widely known phosphorescent host material. Recently, Pioneer (Japan) et al., developed a high performance organic electroluminescent device using bathocuproine (BCP) and aluminum(III) bis(2-methyl-8-quinolinate)(4-phenylphenolate) (BAlq), etc., which were known as hole blocking materials, as host materials.

Although these materials provide good luminous characteristics, they have the following disadvantages: (1) Due to their low glass transition temperature and poor thermal stability, their degradation may occur during a high-temperature deposition process in a vacuum, and the lifespan of the device decreases. (2) The power efficiency of the organic electroluminescent device is given by [(π/voltage) × current efficiency], and the power efficiency is inversely proportional to the voltage. Although the organic electroluminescent device comprising phosphorescent host materials provides higher current efficiency (cd/A) than one comprising fluorescent materials, a significantly high driving voltage is necessary. Thus, there is no merit in terms of power efficiency (lm/W). (3) Further, when these materials are used in an organic electroluminescent device, the operational lifespan of an organic electroluminescent device is short and luminous efficiency is still required to be improved.

In order to enhance luminous efficiency, driving voltage, and/or lifespan, various materials or concepts for an organic layer of an organic electroluminescent device have been proposed, but they have not been satisfactory in practical use.

Korean Patent Application Laying-Open No. 2018-0012709 discloses a compound of a fused structure comprising an indolocarbazole and an azepine. However, said reference does not specifically disclose a compound in which an aryl or a heteroaryl is bonded to the core structure.

The objective of the present disclosure is firstly, to provide an organic electroluminescent compound effective for producing an organic electroluminescent device having improved driving voltage, luminous efficiency, lifespan characteristic, and/or power efficiency, and secondly, to provide an organic electroluminescent device comprising the organic electroluminescent compound.

The present inventors have found that the above objective can be achieved by an organic electroluminescent compound represented by the following formula 1:

wherein

X₁ to X₁₃, each independently, represent N or CR₁, in which at least one of X₁ to X₁₃ is CR₁;

L represents a single bond, a substituted or unsubstituted (C6-C30)arylene, a substituted or unsubstituted (3- to 30-membered)heteroarylene, or a substituted or unsubstituted (C3-C30)cycloalkylene;

R₁, each independently, represents hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C1-C30)alkoxy, -SiR₂R₃R₄, or -NR₅R₆; or may be linked to an adjacent substituent to form a ring(s);

if a plurality of R₁ is present, each of R₁ may be the same or different, in which at least one R₁ represents a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 30-membered)heteroaryl;

Ar, each independently, represents hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C1-C30)alkoxy, -SiR₂R₃R₄, or -NR₅R₆;

R₂ to R₆, each independently, represent hydrogen, deuterium, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, or a substituted or unsubstituted (C3-C30)cycloalkyl; or may be linked to an adjacent substituent to form a ring(s); if a plurality of R₂, a plurality of R₃, a plurality of R₄, a plurality of R₅, and a plurality of R₆ are present, each of R₂, each of R₃, each of R₄, each of R₅, and each of R₆ may be the same or different; and

a represents an integer of 1 to 3, in which, if a is an integer of 2 or more, each of Ar may be the same or different.

By using the organic electroluminescent compound according to the present disclosure, it is possible to produce an organic electroluminescent device having low driving voltage, high luminous efficiency, excellent lifespan characteristic, and/or high power efficiency.

Hereinafter, the present disclosure will be described in detail. However, the following description is intended to explain the disclosure, and is not meant in any way to restrict the scope of the disclosure.

The term "organic electroluminescent compound" in the present disclosure means a compound that may be used in an organic electroluminescent device. If necessary, the organic electroluminescent compound may be comprised in any layer constituting an organic electroluminescent device.

The term "organic electroluminescent material" in the present disclosure means a material that may be used in an organic electroluminescent device, and may comprise at least one compound. If necessary, the organic electroluminescent material may be comprised in any layer constituting an organic electroluminescent device. For example, the organic electroluminescent material may be a hole injection material, a hole transport material, a hole auxiliary material, a light-emitting auxiliary material, an electron blocking material, a light-emitting material, an electron buffer material, a hole blocking material, an electron transport material, an electron injection material, etc.

The organic electroluminescent material of the present disclosure may comprise at least one compound represented by formula 1. The compound represented by formula 1 may be comprised in a light-emitting layer, an electron transport layer, and/or an electron buffer layer, but is not limited thereto. When comprised in a light-emitting layer, the compound represented by formula 1 may be comprised as a host material, in which the host material may be a host material of a green or red organic electroluminescent device. Further, when comprised in an electron transport layer, the compound represented by formula 1 may be comprised as an electron transport material. In addition, when comprised in an electron buffer layer, the compound represented by formula 1 may be comprised as an electron buffer material.

Hereinafter, the compound represented by formula 1 will be described in more detail.

Herein, the term "(C1-C30)alkyl" is meant to be a linear or branched alkyl having 1 to 30 carbon atoms constituting the chain, in which the number of carbon atoms is preferably 1 to 20, and more preferably 1 to 10. The above alkyl may include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, etc. The term "(C2-C30)alkenyl" is meant to be a linear or branched alkenyl having 2 to 30 carbon atoms constituting the chain, in which the number of carbon atoms is preferably 2 to 20, and more preferably 2 to 10. The above alkenyl may include vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-methylbut-2-enyl, etc. The term "(C2-C30)alkynyl" is meant to be a linear or branched alkynyl having 2 to 30 carbon atoms constituting the chain, in which the number of carbon atoms is preferably 2 to 20, and more preferably 2 to 10. The above alkynyl may include ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-methylpent-2-ynyl, etc. The term "(C3-C30)cycloalkyl(ene)" is meant to be a mono- or polycyclic hydrocarbon having 3 to 30 ring backbone carbon atoms, in which the number of carbon atoms is preferably 3 to 20, and more preferably 3 to 7. The above cycloalkyl may include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc. The term "(3- to 7-membered)heterocycloalkyl" is meant to be a cycloalkyl having 3 to 7, preferably 5 to 7, ring backbone atoms, and including at least one heteroatom selected from the group consisting of B, N, O, S, Si, and P, and preferably the group consisting of O, S, and N. The above heterocycloalkyl may include tetrahydrofuran, pyrrolidine, thiolan, tetrahydropyran, etc. The term "(C6-C30)aryl(ene)" is meant to be a monocyclic or fused ring radical derived from an aromatic hydrocarbon having 6 to 30 ring backbone carbon atoms, in which the number of the ring backbone carbon atoms is preferably 6 to 25, more preferably 6 to 18. The above aryl(ene) may be partially saturated, and may comprise a spiro structure. The above aryl may include phenyl, biphenyl, terphenyl, naphthyl, binaphthyl, phenylnaphthyl, naphthylphenyl, phenylterphenyl, fluorenyl, phenylfluorenyl, benzofluorenyl, dibenzofluorenyl, phenanthrenyl, phenylphenanthrenyl, anthracenyl, indenyl, triphenylenyl, pyrenyl, tetracenyl, perylenyl, chrysenyl, naphthacenyl, fluoranthenyl, spirobifluorenyl, azulenyl, etc. More specifically, the above aryl may include phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, benzanthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, 9-phenanthryl, naphthacenyl, pyrenyl, 1-chrysenyl, 2-chrysenyl, 3-chrysenyl, 4-chrysenyl, 5-chrysenyl, 6-chrysenyl, benzo[c]phenanthryl, benzo[g]chrysenyl, 1-triphenylenyl, 2-triphenylenyl, 3-triphenylenyl, 4-triphenylenyl, 1-fluorenyl, 2-fluorenyl, 3-fluorenyl, 4-fluorenyl, 9-fluorenyl, benzofluorenyl, dibenzofluorenyl, 2-biphenylyl, 3-biphenylyl, 4-biphenylyl, o-terphenyl, 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-t-butylphenyl, p-(2-phenylpropyl)phenyl, 4'-methylbiphenylyl, 4"-t-butyl-p-terphenyl-4-yl, 9,9-dimethyl-1-fluorenyl, 9,9-dimethyl-2-fluorenyl, 9,9-dimethyl-3-fluorenyl, 9,9-dimethyl-4-fluorenyl, 9,9-diphenyl-1-fluorenyl, 9,9-diphenyl-2-fluorenyl, 9,9-diphenyl-3-fluorenyl, 9,9-diphenyl-4-fluorenyl, etc.

The term "(3- to 30-membered)heteroaryl(ene)" is an aryl having 3 to 30 ring backbone atoms, and including at least one, preferably 1 to 4 heteroatoms selected from the group consisting of B, N, O, S, Si, and P. The above heteroaryl(ene) may be a monocyclic ring, or a fused ring condensed with at least one benzene ring; may be partially saturated; may be one formed by linking at least one heteroaryl or aryl group to a heteroaryl group via a single bond(s); and may comprise a spiro structure. The above heteroaryl may include a monocyclic ring-type heteroaryl such as furyl, thiophenyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, triazinyl, tetrazinyl, triazolyl, tetrazolyl, furazanyl, pyridyl, pyrazinyl, pyrimidinyl, and pyridazinyl, and a fused ring-type heteroaryl such as benzofuranyl, benzothiophenyl, isobenzofuranyl, dibenzofuranyl, dibenzothiophenyl, benzimidazolyl, benzothiazolyl, benzoisothiazolyl, benzoisoxazolyl, benzoxazolyl, isoindolyl, indolyl, benzoindolyl, indazolyl, benzothiadiazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl, benzoquinazolinyl, quinoxalinyl, benzoquinoxalinyl, naphthyridinyl, carbazolyl, benzocarbazolyl, dibenzocarbazolyl, phenoxazinyl, phenothiazinyl, phenanthridinyl, benzodioxolyl, and dihydroacridinyl. More specifically, the above heteroaryl may include 1-pyrrolyl, 2-pyrrolyl, 3-pyrrolyl, pyrazinyl, 2-pyridinyl, 2-pyrimidinyl, 4-pyrimidinyl, 5-pyrimidinyl, 6-pyrimidinyl, 1,2,3-triazin-4-yl, 1,2,4-triazin-3-yl, 1,3,5-triazin-2-yl, 1-imidazolyl, 2-imidazolyl, 1-pyrazolyl, 1-indolidinyl, 2-indolidinyl, 3-indolidinyl, 5-indolidinyl, 6-indolidinyl, 7-indolidinyl, 8-indolidinyl, 2-imidazopyridinyl, 3-imidazopyridinyl, 5-imidazopyridinyl, 6-imidazopyridinyl, 7-imidazopyridinyl, 8-imidazopyridinyl, 3-pyridinyl, 4-pyridinyl, 1-indolyl, 2-indolyl, 3-indolyl, 4-indolyl, 5-indolyl, 6-indolyl, 7-indolyl, 1-isoindolyl, 2-isoindolyl, 3-isoindolyl, 4-isoindolyl, 5-isoindolyl, 6-isoindolyl, 7-isoindolyl, 2-furyl, 3-furyl, 2-benzofuranyl, 3-benzofuranyl, 4-benzofuranyl, 5-benzofuranyl, 6-benzofuranyl, 7-benzofuranyl, 1-isobenzofuranyl, 3-isobenzofuranyl, 4-isobenzofuranyl, 5-isobenzofuranyl, 6-isobenzofuranyl, 7-isobenzofuranyl, 2-quinolyl, 3-quinolyl, 4-quinolyl, 5-quinolyl, 6-quinolyl, 7-quinolyl, 8-quinolyl, 1-isoquinolyl, 3-isoquinolyl, 4-isoquinolyl, 5-isoquinolyl, 6-isoquinolyl, 7-isoquinolyl, 8-isoquinolyl, 2-quinoxalinyl, 5-quinoxalinyl, 6-quinoxalinyl, 1-carbazolyl, 2-carbazolyl, 3-carbazolyl, 4-carbazolyl, 9-carbazolyl, 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-t-butylpyrrol-4-yl, 3-(2-phenylpropyl)pyrrol-1-yl, 2-methyl-1-indolyl, 4-methyl-1-indolyl, 2-methyl-3-indolyl, 4-methyl-3-indolyl, 2-t-butyl-1-indolyl, 4-t-butyl-1-indolyl, 2-t-butyl-3-indolyl, 4-t-butyl-3-indolyl, 1-dibenzofuranyl, 2-dibenzofuranyl, 3-dibenzofuranyl, 4-dibenzofuranyl, 1-dibenzothiophenyl, 2-dibenzothiophenyl, 3-dibenzothiophenyl, 4-dibenzothiophenyl, 1-silafluorenyl, 2-silafluorenyl, 3-silafluorenyl, 4-silafluorenyl, 1-germafluorenyl, 2-germafluorenyl, 3-germafluorenyl, 4-germafluorenyl, etc. Furthermore, "halogen" includes F, Cl, Br, and I.

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

Herein, "substituted" in the expression "substituted or unsubstituted" means that a hydrogen atom in a certain functional group is replaced with another atom or another functional group, i.e., a substituent. The substituents of the substituted (C1-C30)alkyl, the substituted (C6-C30)aryl(ene), the substituted (3- to 30-membered)heteroaryl(ene), the substituted (C3-C30)cycloalkyl(ene), the substituted (C1-C30)alkoxy, the substituted tri(C1-C30)alkylsilyl, the substituted di(C1-C30)alkyl(C6-C30)arylsilyl, the substituted (C1-C30)alkyldi(C6-C30)arylsilyl, the substituted tri(C6-C30)arylsilyl, the substituted mono- or di- (C1-C30)alkylamino, the substituted mono- or di- (C6-C30)arylamino, and the substituted (C1-C30)alkyl(C6-C30)arylamino, each independently, may be at least one selected from the group consisting of deuterium; a halogen; a cyano; a carboxyl; a nitro; a hydroxyl; a (C1-C30)alkyl; a halo(C1-C30)alkyl; a (C2-C30)alkenyl; a (C2-C30)alkynyl; a (C1-C30)alkoxy; a (C1-C30)alkylthio; a (C3-C30)cycloalkyl; a (C3-C30)cycloalkenyl; a (3- to 7-membered)heterocycloalkyl; a (C6-C30)aryloxy; a (C6-C30)arylthio; a (5- to 30-membered)heteroaryl unsubstituted or substituted with a (C6-C30)aryl(s); a (C6-C30)aryl unsubstituted or substituted with a (5- to 30-membered)heteroaryl(s); a tri(C1-C30)alkylsilyl; a tri(C6-C30)arylsilyl; a di(C1-C30)alkyl(C6-C30)arylsilyl; a (C1-C30)alkyldi(C6-C30)arylsilyl; an amino; a mono- or di- (C1-C30)alkylamino; a mono- or di- (C6-C30)arylamino unsubstituted or substituted with a (C1-C30)alkyl(s); a (C1-C30)alkyl(C6-C30)arylamino; a (C1-C30)alkylcarbonyl; a (C1-C30)alkoxycarbonyl; a (C6-C30)arylcarbonyl; a di(C6-C30)arylboronyl; a di(C1-C30)alkylboronyl; a (C1-C30)alkyl(C6-C30)arylboronyl; a (C6-C30)aryl(C1-C30)alkyl; and a (C1-C30)alkyl(C6-C30)aryl. According to one embodiment of the present disclosure, the substituents, each independently, may be at least one selected from the group consisting of a (C1-C6)alkyl, a (C6-C15)aryl, a (5- to 15-membered)heteroaryl, and/or a (C1-C6)alkyl(C6-C15)aryl. Specifically, the substituents, each independently, may be at least one selected from the group consisting of methyl, tert-butyl, phenyl, biphenyl, dimethylfluorenyl, pyridinyl, dibenzofuranyl, dibenzothiophenyl, and/or carbazolyl, etc.

The compound of the present disclosure may be represented by the following formula 1-1:

wherein

L, Ar, and a are as defined in formula 1 above;

R_a to R_m, each independently, represent hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C1-C30)alkoxy, -SiR₂R₃R₄, or -NR₅R₆; or may be linked to an adjacent substituent to form a ring(s); with the proviso that at least one of R_a to R_m represents a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 30-membered)heteroaryl; and

R₂ to R₆ are as defined in formula 1 above.

In formula 1, X₁ to X₁₃, each independently, represent N or CR₁, in which at least one of X₁ to X₁₃ is CR₁.

In formula 1, L represents a single bond, 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 a single bond, a substituted or unsubstituted (C6-C15)arylene, or a substituted or unsubstituted (5- to 20-membered)heteroarylene; and more preferably a single bond, an unsubstituted (C6-C15)arylene, or a (5- to 20-membered)heteroarylene unsubstituted or substituted with a (C1-C6)alkyl(s). The heteroarylene may comprise at least one of nitrogen, oxygen, and sulfur. According to one embodiment of the present disclosure, L may represent a single bond, phenylene, naphthylene, pyridylene, pyrimidinylene, triazinylene, quinolinylene, quinazolinylene, quinoxalinylene, naphthyridinylene, carbazolylene, benzofuropyrimidinylene, benzothienopyrimidinylene, dimethylindenopyrimidinylene, benzoquinoxalinylene, benzocarbazolylene, etc.

In formula 1, R₁, each independently, represents hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C1-C30)alkoxy, -SiR₂R₃R₄, or -NR₅R₆; or may be linked to an adjacent substituent to form a ring(s). If a plurality of R₁ is present, each of R₁ may be the same or different, in which at least one R₁ represents a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 30-membered)heteroaryl.

Preferably, R₁, each independently, represents hydrogen, a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (5- to 15-membered)heteroaryl. More preferably, R₁, each independently, represents hydrogen; a (C6-C30)aryl unsubstituted or substituted with a (C1-C6)alkyl(s), a (5- to 15-membered)heteroaryl(s), and/or a (C1-C6)alkyl(C6-C15)aryl(s); or a (5- to 15-membered)heteroaryl unsubstituted or substituted with a (C6-C15)aryl(s). According to one embodiment of the present disclosure, R₁ may, each independently, represent hydrogen; a phenyl; a naphthyl; a biphenyl; a terphenyl; a quaterphenyl; a phenyl substituted with a dimethylfluorenyl(s); a phenyl substituted with a dibenzofuranyl(s); a phenyl substituted with a carbazolyl(s); a biphenyl substituted with a dimethylfluorenyl(s); a biphenyl substituted with a dibenzofuranyl(s); a biphenyl substituted with a dibenzothiophenyl(s); a pyridinyl; a pyridinyl substituted with a biphenyl(s); a triazinyl substituted with a phenyl(s); a quinazolinyl substituted with a phenyl(s); a carbazolinyl substituted with a phenyl(s), etc.

In formula 1, Ar, each independently, represents hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C1-C30)alkoxy, -SiR₂R₃R₄, or -NR₅R₆.

Preferably, Ar represents a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (5- to 20-membered)heteroaryl, or -NR₅R₆. More preferably, Ar represents a (C6-C30)aryl unsubstituted or substituted with a (C1-C6)alkyl(s); a (5- to 20-membered)heteroaryl unsubstituted or substituted with a (C6-C12)aryl(s) and/or a (5- to 15-membered)heteroaryl(s); or -NR₅R₆. According to one embodiment of the present disclosure, Ar may, each independently, represent a phenyl; a naphthyl; a biphenyl; a terphenyl; a phenyl substituted with a tert-butyl(s); a diphenylfluorenyl; a pyridinyl; a triazinyl substituted with a phenyl(s); a triazinyl substituted with a phenyl(s) and a pyridinyl(s); a carbazolyl; a dibenzofuranyl; dibenzothiophenyl; a carbazolyl substituted with a phenyl(s); a benzonaphthofuranyl; a diphenylamino, etc.

In formula 1, R₂ to R₆, each independently, represent hydrogen, deuterium, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, or a substituted or unsubstituted (C3-C30)cycloalkyl; or may be linked to an adjacent substituent to form a ring(s); if a plurality of R₂, a plurality of R₃, a plurality of R₄, a plurality of R₅, and a plurality of R₆ are present, each of R₂, each of R₃, each of R₄, each of R₅, and each of R₆ may be the same or different. Preferably, R₂ to R₆, each independently, represent a substituted or unsubstituted (C6-C12)aryl. More preferably, R₂ to R₆, each independently, represent an unsubstituted (C6-C12)aryl. According to one embodiment of the present disclosure, R₂ to R₆, each independently, may represent a phenyl, etc.

In formula 1, a represents an integer of 1 to 3, in which, if a is an integer of 2 or more, each of Ar may be the same or different. According to one embodiment of the present disclosure, a represents 1 or 2.

According to one embodiment of the present disclosure, in formula 1, Ar and R₁, each independently, may be hydrogen or selected from any one of the substituents listed in the following group 1, in which at least one R₁ is selected from the following group 1.

[Group 1]

wherein

D1 and D2, each independently, represent a benzene ring or a naphthalene ring;

X₂₁ represents O, S, NR₂₂, or CR₂₃R₂₄;

X₂₂, each independently, represents CR₃₁ or N, in which at least one X₂₂ represents N;

X₂₃, each independently, represents CR₃₂ or N;

L₁₁ to L₁₃ and L₁₅ to L₁₈, each independently, represent a single bond, a substituted or unsubstituted (C6-C30)arylene, or a substituted or unsubstituted (3- to 30-membered)heteroarylene;

L₁₄ represents a substituted or unsubstituted (C6-C30)arylene, or a substituted or unsubstituted (3- to 30-membered)heteroarylene;

R₁₁ to R₂₄, R₃₁, and R₃₂, each independently, represent hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, or a substituted or unsubstituted (C3-C30)cycloalkyl; or may be linked to an adjacent substituent to form a substituted or unsubstituted ring(s); and

aa, ff, and gg, each independently, represent an integer of 1 to 5; bb represents a integer of 1 to 7; and cc, dd, and ee, each independently, represent an integer of 1 to 4.

According to another embodiment of the present disclosure, in formula 1, Ar and R₁, each independently, may hydrogen or selected from any one of the substituents listed in the following group 2, in which at least one R₁ is selected from the following group 2.

[Group 2]

wherein

L₁ is identical to the definition of L in formula 1 above, and

A₁ to A₃, each independently, represent a substituted or unsubstituted (C1-C30)alkyl, or a substituted or unsubstituted (C6-C30)aryl.

According to another embodiment of the present disclosure, in formula 1, Ar and R₁, each independently, may be hydrogen or selected from any one of the substituents listed in the following group 3, in which at least one R₁ is selected from the following group 3.

[Group 3]

According to one embodiment of the present disclosure, X₁ to X₁₃, each independently, represent N or CR₁, in which at least one of X₁ to X₁₃ is CR₁; L represents a single bond, a substituted or unsubstituted (C6-C15)arylene, or a substituted or unsubstituted (5- to 20-membered)heteroarylene; R₁, each independently, represents hydrogen, a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (5- to 15-membered)heteroaryl, in which at least one R₁ represents a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 30-membered)heteroaryl; Ar represents a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (5- to 20-membered)heteroaryl, or -NR₅R₆; R₂ to R₆, each independently, represent a substituted or unsubstituted (C6-C12)aryl; and a represents 1 or 2.

According to another embodiment of the present disclosure, X₁ to X₁₃, each independently, represent N or CR₁, in which at least one of X₁ to X₁₃ is CR₁; L represents a single bond, an unsubstituted (C6-C15)arylene, or a (5- to 20-membered)heteroarylene unsubstituted or substituted with a (C1-C6)alkyl(s); R₁, each independently, represents hydrogen; a (C6-C30)aryl unsubstituted or substituted with a (C1-C6)alkyl(s), a (5- to 15-membered)heteroaryl(s), and/or a (C1-C6)alkyl(C6-C15)aryl(s); or a (5- to 15-membered)heteroaryl unsubstituted or substituted with a (C6-C15)aryl(s); with the proviso that at least one R₁ represents a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 30-membered)heteroaryl; Ar represents a (C6-C30)aryl unsubstituted or substituted with a (C1-C6)alkyl(s); a (5- to 20-membered)heteroaryl unsubstituted or substituted with a (C6-C12)aryl(s) and/or a (5- to 15-membered)heteroaryl(s); or -NR₅R₆; R₂ to R₆, each independently, represent an unsubstituted (C6-C12)aryl; and a represents 1 or 2.

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

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

The compound represented by formula 1 includes the following compounds, but is not limited thereto.

The compound represented by formula 1 according to the present disclosure may be produced by a synthetic method known to one skilled in the art based on KR 2018-0012709 A. For example, the organic electroluminescent compound of the present disclosure may be synthesized as shown in the following reaction scheme, but is not limited thereto.

[Reaction Scheme 1]

In reaction scheme 1, X₁ to X₁₃, L, Ar, and a are as defined in formula 1.

Although illustrative synthesis examples of the compound represented by formula 1 were described above, one skilled in the art will be able to readily understand that all of them are based on a Buchwald-Hartwig cross-coupling reaction, an N-arylation reaction, a H-mont-mediated etherification reaction, a Miyaura borylation reaction, a Suzuki cross-coupling reaction, an Intramolecular acid-induced cyclization reaction, a Pd(II)-catalyzed oxidative cyclization reaction, a Grignard reaction, a Heck reaction, a Cyclic Dehydration reaction, an SN₁ substitution reaction, an SN₂ substitution reaction, and a Phosphine-mediated reductive cyclization reaction, and the above reactions proceed even when substituents, which are defined in formula 1 above but are not specified in the specific synthesis examples, are bonded.

The present disclosure provides an organic electroluminescent material comprising the compound represented by formula 1, and an organic electroluminescent device comprising the organic electroluminescent material.

The organic electroluminescent material may consist of the compound according to the present disclosure alone, or may further comprise conventional materials included in organic electroluminescent materials.

The organic electroluminescent compound represented by formula 1 of the present disclosure may be comprised in at least one of a light-emitting layer, a hole injection layer, a hole transport layer, a hole auxiliary layer, a light-emitting auxiliary layer, an electron transport layer, an electron buffer layer, an electron injection layer, an interlayer, a hole blocking layer, and an electron blocking layer, preferably in a light-emitting layer. When used in a light-emitting layer, the organic electroluminescent compound represented by formula 1 of the present disclosure may be comprised as a host material. Preferably, the light-emitting layer may further comprise at least one dopant. If necessary, the organic electroluminescent compound of the present disclosure may be used as a co-host material. That is, the light-emitting layer may further include an organic electroluminescent compound other than the organic electroluminescent compound represented by formula 1 of the present disclosure (first host material) as a second host material. In this case, the weight ratio between the first host material and the second host material is in the range of 1:99 to 99:1. When two or more materials are included in one layer, mixed deposition may be performed to form a layer, or co-deposition may be performed separately to form a layer.

The second host material may be selected from any of the known host materials. Preferably, the second host material may be selected from the group consisting of the compounds represented by the following formulas 11 to 16:

wherein Cz represents the following structure:

A represents -O- or -S-;

R₄₁ to R₄₄, each independently, represent hydrogen, deuterium, a halogen, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (5- to 30-membered)heteroaryl, or -SiR₄₅R₄₆R₄₇, where R₄₅ to R₄₇, each independently, represent a substituted or unsubstituted (C1-C30)alkyl, or a substituted or unsubstituted (C6-C30)aryl;

L₄ represents a single bond, a substituted or unsubstituted (C6-C30)arylene, or a substituted or unsubstituted (5- to 30-membered)heteroarylene;

M represents a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (5- to 30-membered)heteroaryl;

Y₁ and Y₂, each independently, represent -O-, -S-, -N(R₅₁)-, or -C(R₅₂)(R₅₃)-, and Y₁ and Y₂ are not present simultaneously;

R₅₁ to R₅₃, each independently, represent a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (5- to 30-membered)heteroaryl, in which R₅₂ and R₅₃ may be the same or different; and

h and i, each independently, represent an integer of 1 to 3; j, k, l and m, each independently, represent an integer of 1 to 4; q represents an integer of 1 to 3; and where h, i, j, k, l, m or q is an integer of 2 or more, each of (Cz-L₄), each of (Cz), each of R₄₁, each of R₄₂, each of R₄₃, or each of R₄₄ may be the same or different.

wherein

Y₃ to Y₅, each independently, represent CR₅₄ or N;

R₅₄ represents hydrogen, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (5- to 30-membered)heteroaryl;

B₁ and B₂, each independently, represent hydrogen, a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (5- to 30-membered)heteroaryl;

B₃ represents a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (5- to 30-membered)heteroaryl; and

L₅ represents a single bond, a substituted or unsubstituted (C6-C30)arylene, or a substituted or unsubstituted (5- to 30-membered)heteroarylene.

Specifically, the examples of the second host material include the following, but are not limited thereto.

wherein TPS represents a triphenylsilyl group.

The dopant comprised in the organic electroluminescent device of the present disclosure is at least one phosphorescent or fluorescent dopant, preferably at least one phosphorescent dopant. The phosphorescent dopant material applied to the organic electroluminescent device of the present disclosure is not particulary limited, but may be preferably selected from the metallated complex compounds of iridium (Ir), osmium (Os), copper (Cu), and platinum (Pt), more preferably selected from ortho-metallated complex compounds of iridium (Ir), osmium (Os), copper (Cu), and platinum (Pt), and even more preferably ortho-metallated iridium complex compounds.

The dopant comprised in the organic electroluminescent device of the present disclosure may be exemplified as a compound represented by the following formula 101, but is not limited thereto.

In formula 101, L is selected from the following structures 1 to 3:

R₁₀₀ to R₁₀₃, each independently, represent hydrogen, deuterium, a halogen, a (C1-C30)alkyl unsubstituted or substituted with a halogen(s), a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C6-C30)aryl, a cyano, a substituted or unsubstituted (3- to 30-membered)heteroaryl, or a substituted or unsubstituted (C1-C30)alkoxy; or may be linked to an adjacent R₁₀₀ to R₁₀₃ to form a substituted or unsubstituted fused ring with a pyridine, e.g., a substituted or unsubstituted quinoline, a substituted or unsubstituted isoquinoline, a substituted or unsubstituted benzofuropyridine, a substituted or unsubstituted benzothienopyridine, a substituted or unsubstituted indenopyridine, a substituted or unsubstituted benzofuroquinoline, a substituted or unsubstituted benzothienoquinoline or a substituted or unsubstituted indenoquinoline;

R₁₀₄ to R₁₀₇, each independently, represent hydrogen, deuterium, a halogen, a (C1-C30)alkyl unsubstituted or substituted with a halogen(s), a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a cyano, or a substituted or unsubstituted (C1-C30)alkoxy; or may be linked to adjacent R₁₀₄ to R₁₀₇ to form a substituted or unsubstituted fused ring with a benzene, e.g., a substituted or unsubstituted naphthyl, a substituted or unsubstituted fluorene, a substituted or unsubstituted dibenzothiophene, a substituted or unsubstituted dibenzofuran, a substituted or unsubstituted indenopyridine, a substituted or unsubstituted benzofuropyridine, or a substituted or unsubstituted benzothienopyridine;

R₂₀₁ to R₂₂₀, each independently, represent hydrogen, deuterium, a halogen, a (C1-C30)alkyl unsubstituted or substituted with a halogen(s), a substituted or unsubstituted (C3-C30)cycloalkyl, or a substituted or unsubstituted (C6-C30)aryl; or may be linked to adjacent R₂₀₁ to R₂₂₀ to form a substituted or unsubstituted fused ring; and

n represents an integer of 1 to 3.

The specific examples of the dopant compound are as follows, but are not limited thereto.

The organic electroluminescent device according to the present disclosure comprises a first electrode; a second electrode; and at least one organic layer between the first and second electrodes.

One of the first and second electrodes may be an anode, and the other may be a cathode. The organic layer may comprise a light-emitting layer, and may further comprise at least one layer selected from a hole injection layer, a hole transport layer, a hole auxiliary layer, a light-emitting auxiliary layer, an electron transport layer, an electron buffer layer, an electron injection layer, an interlayer, a hole blocking layer, and an electron blocking layer. Each of the layers may further consist of multi-layers.

The first electrode and the second electrode may each be formed with a transmissive conductive material, a transflective conductive material, or a reflective conductive material. The organic electroluminescent device may be a top emission type, a bottom emission type, or both-sides emission type according to the kinds of the material forming the first electrode and the second electrode. In addition, the hole injection layer may be further doped with a p-dopant, and the electron injection layer may be further doped with an n-dopant.

According to one embodiment of the present disclosure, the organic electroluminescent device according to the present disclosure may further comprise an azine-based compound as at least one selected from an electron transport material, an electron injection material, an electron buffer material, and a hole blocking material, in addition to the organic electroluminescent compound of the present disclosure.

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

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

The organic electroluminescent device of the present disclosure may emit white light by further including at least one light-emitting layer containing a blue, red, or green light-emitting compound, which is known in the art, besides the compound of the present disclosure. In addition, it may further include a yellow or orange light-emitting layer, if necessary.

In the organic electroluminescent device of the present disclosure, at least one layer selected from a chalcogenide layer, a metal halide layer and a metal oxide layer (hereinafter, "a surface layer") may be preferably placed on an inner surface(s) of one or both electrodes. Specifically, a chalcogenide (including oxides) layer of silicon or aluminum is preferably placed on an anode surface of an electroluminescent medium layer, and a metal halide layer or a metal oxide layer is preferably placed on a cathode surface of an electroluminescent medium layer. The surface layer may provide operation stability for the organic electroluminescent device. Preferably, the chalcogenide includes SiO_X (1≤X≤2), AlO_X (1≤X≤1.5), SiON, SiAlON, etc.; the metal halide includes LiF, MgF₂, CaF₂, a rare earth metal fluoride, etc.; and the metal oxide includes Cs₂O, Li₂O, MgO, SrO, BaO, CaO, etc.

A hole injection layer, a hole transport layer, or an electron blocking layer, or a combination thereof may be used between the anode and the light-emitting layer. The hole injection layer may be multilayers in order to lower the hole injection barrier (or hole injection voltage) from the anode to the hole transport layer or the electron blocking layer, wherein each of the multilayers may use two compounds simultaneously. The hole transport layer or the electron blocking layer may also be multilayers.

An electron buffer layer, a hole blocking layer, an electron transport layer, or an electron injection layer, or a combination thereof can be used between the light-emitting layer and the cathode. The electron buffer layer may be multilayers in order to control the injection of the electron and improve the interfacial properties between the light-emitting layer and the electron injection layer, wherein each of the multilayers may use two compounds simultaneously. The hole blocking layer or the electron transport layer may also be multilayers, wherein each of the multilayers may use a plurality of compounds.

The light-emitting auxiliary layer may be placed between the anode and the light-emitting layer, or between the cathode and the light-emitting layer. When the light-emitting auxiliary layer is placed between the anode and the light-emitting layer, it can be used for promoting the hole injection and/or the hole transport, or for preventing the overflow of electrons. When the light-emitting auxiliary layer is placed between the cathode and the light-emitting layer, it can be used for promoting the electron injection and/or the electron transport, or for preventing the overflow of holes. In addition, the hole auxiliary layer may be placed between the hole transport layer (or hole injection layer) and the light-emitting layer, and may be effective to promote or block the hole transport rate (or the hole injection rate), thereby enabling the charge balance to be controlled. Further, the electron blocking layer may be placed between the hole transport layer (or hole injection layer) and the light-emitting layer, and may block overflowing electrons from the light-emitting layer and confine the excitons in the light-emitting layer to prevent light leakage. When an organic electroluminescent device includes two or more hole transport layers, the hole transport layer, which is further included, may be used as a hole auxiliary layer or an electron blocking layer. The hole auxiliary layer and the electron blocking layer may have an effect of improving the efficiency and/or the lifespan of the organic electroluminescent device.

In the organic electroluminescent device of the present disclosure, a mixed region of an electron transport compound and a reductive dopant, or a mixed region of a hole transport compound and an oxidative dopant is preferably placed on at least one surface of a pair of electrodes. In this case, the electron transport compound is reduced to an anion, and thus it becomes easier to inject and transport electrons from the mixed region to an electroluminescent medium. Further, the hole transport compound is oxidized to a cation, and thus it becomes easier to inject and transport holes from the mixed region to the electroluminescent medium. Preferably, the oxidative dopant includes various Lewis acids and acceptor compounds; and the reductive dopant includes alkali metals, alkali metal compounds, alkaline earth metals, rare-earth metals, and mixtures thereof. A reductive dopant layer may be employed as a charge-generating layer to produce an organic electroluminescent device having two or more light-emitting layers, which emits white light.

An organic electroluminescent material according to one embodiment of the present disclosure may be used as light-emitting materials for a white organic light-emitting device. The white organic light-emitting device has been suggested to have various structures such as a parallel arrangement (side-by-side) method, a stacking method, or color conversion material (CCM) method, etc., according to the arrangement of R (red), G (green), B (blue), or YG (yellowish green) light-emitting units. In addition, the organic electroluminescent material according to one embodiment of the present disclosure may also be applied to the organic electroluminescent device comprising a quantum dot (QD).

In order to form each layer of the organic electroluminescent device of the present disclosure, dry film-forming methods such as vacuum evaporation, sputtering, plasma, ion plating, etc., or wet film-forming methods such as ink jet printing, spin coating, dip coating, flow coating, etc., can be used. The first and second host compounds of the present disclosure may be co-evaporated or mixture-evaporated to form a film.

When using a wet film-forming method, a thin film can be formed by dissolving or diffusing the materials forming each layer into any suitable solvent such as ethanol, chloroform, tetrahydrofuran, dioxane, etc. The solvent is not particularly limited as long as the material constituting each layer is soluble or dispersible in the solvents, which do not cause any problems in forming a film.

It is possible to produce a display system, e.g., a display system for smartphones, tablets, notebooks, PCs, TVs, or cars, or a lighting system, e.g., an outdoor or indoor lighting system, by using the organic electroluminescent device of the present disclosure.

Hereinafter, the preparation method of the compound of the present disclosure, and the properties thereof will be explained in detail with reference to the representative compounds of the present disclosure. However, the present disclosure is not limited to the following examples.

Example 1: Preparation of compound C-74

Synthesis of compound 3

In a flask, 50.0 g of compound 1 (205.7 mmol), 87.0 g of compound 2 (308.5 mmol), 16.4 g of CuSO₄ (102.9 mmol), and 56.9 g of K₂CO₃ (411.4 mmol) were dissolved in 1000 mL of 1,2-dichlorobenzene, and the mixture was stirred under reflux for 1 day. The reaction mixture was distilled to remove the solvent. Thereafter, the residue was separated by column chromatography to obtain 71.9 g of compound 3 (yield: 88%).

Synthesis of compound 4

450 mL of toluene and 450 mL of tetrahydrofuran (THF) were introduced into a flask, and 100.0 mL of n-BuLi (252.7 mmol) was added dropwise thereto at -78℃. Next, 71.9 g of compound 3 (180.5 mmol) and 62.0 mL of B(OiPr)₃ (270.8 mmol) were added to the flask, and the mixture was stirred under reflux at room temperature for 1 day. After completion of the reaction, the reaction mixture was extracted with ethyl acetate (EA)/H₂O, and concentrated to obtain 49.4 g of compound 4 (yield: 75%).

Synthesis of compound 6

47.4 g of compound 4 (316.8 mmol), 62.0 g of compound 5 (261.0 mmol), 45.0 g of K₂CO₃ (326.3 mmol), 650 mL of o-xylene, 160 mL of 1,4-dioxane, and 160 mL of H₂O were introduced into a flask, and the mixture was stirred under reflux at 200℃ for 18 hours. After completion of the reaction, the reaction mixture was extracted with EA/H₂O, and separated by column chromatography to obtain 47.9 g of compound 6 (yield: 77%).

Synthesis of compound 7

49.3 g of compound 6 (103.8 mmol), 2.3 g of Pd(OAc)₂ (10.4 mmol), 7.5 g of tricyclohexylphosphonium tetrafluoroborate (20.8 mmol), 101.5 g of cesium carbonate (Cs₂CO₃) (311.4 mmol), and 520 mL of o-xylene were introduced into a flask, and the mixture was stirred under reflux for 3 hours and 30 minutes. After completion of the reaction, the reaction mixture was extracted with EA/H₂O, and separated by column chromatography to obtain 38.1 g of compound 7 (yield: 84%).

Synthesis of compound 8

38.1 g of compound 7 (86.9 mmol), 57.0 g of PPh₃ (217.2 mmol) and 440 mL of 1,2-dichlorobenzene were introduced into a flask, and the mixture was stirred under reflux for 17 hours. After completion of the reaction, the mixture was distilled, and separated by column chromatography to obtain 29.5 g of compound 8 (yield: 84%).

Synthesis of compound C-74

5.0 g of compound 8 (12.3 mmol), 4.4 g of compound 9 (18.5 mmol), 0.75 g of DMAP (6.2 mmol), 6.0 g of Cs₂CO₃ (18.5 mmol) and 62 mL of dimethyl sulfoxide (DMSO) were introduced into a flask, and the mixture was stirred 100℃ for 1 hour. After completion of the reaction, the reaction mixture was extracted with EA/H₂O, and separated by column chromatography to obtain 5.8 g of compound C-74 (yield: 77%).

Example 2: Preparation of compound C-13

4.2 g of compound 10 (10 mmol), 7.4 g of 2-chloro-3-phenylquinoxaline (30.7 mmol), 1.262 g of dimethylaminopyridine (DMAP) (10 mmol), 40.4 g of Cs₂CO₃ (124 mmol) and 50 mL of DMSO were introduced into a flask, and the mixture was stirred under reflux for 24 hours. After completion of the reaction, the reaction mixture was extracted with EA/H₂O, and separated by column chromatography to obtain 2.0 g of compound C-13 (yield: 32%).

Device Example 1: Producing an OLED deposited with a compound according

to the present disclosure as a host

An OLED comprising a compound according to the present disclosure was produced as follows: A transparent electrode indium tin oxide (ITO) thin film (10 Ω/sq) on a glass substrate for an OLED (GEOMATEC CO., LTD., Japan) was subjected to an ultrasonic washing with acetone, ethanol, and distilled water, sequentially, and then was stored in isopropyl alcohol. The ITO substrate was mounted on a substrate holder of a vacuum vapor deposition apparatus. Compound HI-1 was introduced into a cell of the vacuum vapor deposition apparatus, and the pressure in the chamber of the apparatus was then controlled to 10^-6 torr. Thereafter, an electric current was applied to the cell to evaporate the above-introduced material, thereby forming a first hole injection layer having a thickness of 80 nm on the ITO substrate. Next, compound HI-2 was introduced into another cell of the vacuum vapor deposition apparatus and was evaporated by applying an electric current to the cell, thereby forming a second hole injection layer having a thickness of 5 nm on the first hole injection layer. Compound HT-1 was then introduced into another cell of the vacuum vapor deposition apparatus and was evaporated by applying an electric current to the cell, thereby forming a first hole transport layer having a thickness of 10 nm on the second hole injection layer. Compound HT-2 was then introduced into another cell of the vacuum vapor deposition apparatus and was evaporated by applying an electric current to the cell, thereby forming a second hole transport layer having a thickness of 60 nm on the first hole transport layer. After forming the hole injection layers and the hole transport layers, a light-emitting layer was formed thereon as follows: The compound shown in Table 1 was introduced into one cell of the vacuum vapor depositing apparatus as a host, and compound D-39 was introduced into another cell as a dopant. The two materials were evaporated at different rates, and respectively deposited in a doping amount of 3 wt% to form a light-emitting layer having a thickness of 40 nm on the second hole transport layer. Next, compound ET-1 and compound EI-1 were evaporated at a rate of 1:1 in two other cells to deposit an electron transport layer having a thickness of 35 nm on the light-emitting layer. After depositing compound EI-1 as an electron injection layer having a thickness of 2 nm on the electron transport layer, an Al cathode having a thickness of 80 nm was deposited on the electron injection layer by another vacuum vapor deposition apparatus. Thus, an OLED was produced.

Comparative Examples 1 and 2: Producing an OLED deposited with a

comparative compound as a host

An OLED was produced in the same manner as in Device Example 1, except that the compound shown in Table 1 was used as a host of the light-emitting layer.

The driving voltage, luminous efficiency, and CIE color coordinates at a luminance of 1,000 nit, and the time taken for luminance to decrease from 100% to 95% at a luminance of 5,000 nit (lifespan; T95) of the OLEDs produced in Device Example 1 and Comparative Examples 1 and 2 are provided in Table 1 below.

The OLED produced by using the organic electroluminescent compound according to the present disclosure as a host exhibited equivalent or lower driving voltage, equivalent or higher luminous efficiency, and longer lifespan characteristic compared to the OLED produced by using the comparative compound as a host.

Claims

An organic electroluminescent compound represented by the following formula 1:

wherein

X₁ to X₁₃, each independently, represent N or CR₁, in which at least one of X₁ to X₁₃ is CR₁;

L represents a single bond, a substituted or unsubstituted (C6-C30)arylene, a substituted or unsubstituted (3- to 30-membered)heteroarylene, or a substituted or unsubstituted (C3-C30)cycloalkylene;

R₁, each independently, represents hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C1-C30)alkoxy, -SiR₂R₃R₄, or -NR₅R₆; or may be linked to an adjacent substituent to form a ring(s);

if a plurality of R₁ is present, each of R₁ may be the same or different, in which at least one R₁ represents a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 30-membered)heteroaryl;

Ar, each independently, represents hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C1-C30)alkoxy, -SiR₂R₃R₄, or -NR₅R₆;

R₂ to R₆, each independently, represent hydrogen, deuterium, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, or a substituted or unsubstituted (C3-C30)cycloalkyl; or may be linked to an adjacent substituent to form a ring(s); if a plurality of R₂, a plurality of R₃, a plurality of R₄, a plurality of R₅, and a plurality of R₆ are present, each of R₂, each of R₃, each of R₄, each of R₅, and each of R₆ may be the same or different; and

a represents an integer of 1 to 3, in which, if a is an integer of 2 or more, each of Ar may be the same or different.
The organic electroluminescent compound according to claim 1, wherein the organic electroluminescent compound is represented by the following formula 1-1:

wherein

L, Ar, and a are as defined in claim 1;

R_a to R_m, each independently, represent hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C1-C30)alkoxy, -SiR₂R₃R₄, or -NR₅R₆; or may be linked to an adjacent substituent to form a ring(s); with the proviso that at least one of R_a to R_m represents a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 30-membered)heteroaryl; and

R₂ to R₆ are as defined in claim 1.
The organic electroluminescent compound according to claim 1, wherein substituents of the substituted (C1-C30)alkyl, the substituted (C6-C30)aryl(ene), the substituted (3- to 30-membered)heteroaryl(ene), the substituted (C3-C30)cycloalkyl(ene), and the substituted (C1-C30)alkoxy in L, Ar, and R₁ to R₆, each independently, are at least one selected from the group consisting of deuterium; a halogen; a cyano; a carboxyl; a nitro; a hydroxyl; a (C1-C30)alkyl; a halo(C1-C30)alkyl; a (C2-C30)alkenyl; a (C2-C30)alkynyl; a (C1-C30)alkoxy; a (C1-C30)alkylthio; a (C3-C30)cycloalkyl; a (C3-C30)cycloalkenyl; a (3- to 7-membered)heterocycloalkyl; a (C6-C30)aryloxy; a (C6-C30)arylthio; a (5- to 30-membered)heteroaryl unsubstituted or substituted with a (C6-C30)aryl(s); a (C6-C30)aryl unsubstituted or substituted with a (5- to 30-membered)heteroaryl(s); a tri(C1-C30)alkylsilyl; a tri(C6-C30)arylsilyl; a di(C1-C30)alkyl(C6-C30)arylsilyl; a (C1-C30)alkyldi(C6-C30)arylsilyl; an amino; a mono- or di- (C1-C30)alkylamino; a mono- or di- (C6-C30)arylamino unsubstituted or substituted with a (C1-C30)alkyl(s); a (C1-C30)alkyl(C6-C30)arylamino; a (C1-C30)alkylcarbonyl; a (C1-C30)alkoxycarbonyl; a (C6-C30)arylcarbonyl; a di(C6-C30)arylboronyl; a di(C1-C30)alkylboronyl; a (C1-C30)alkyl(C6-C30)arylboronyl; a (C6-C30)aryl(C1-C30)alkyl; and a (C1-C30)alkyl(C6-C30)aryl.
The organic electroluminescent compound according to claim 1, wherein Ar and R₁, each independently, are hydrogen or selected from any one of the substituents listed in the following group 1, in which at least one R₁ is selected from the following group 1:

[Group 1]

wherein

D1 and D2, each independently, represent a benzene ring or a naphthalene ring;

X₂₁ represents O, S, NR₂₂, or CR₂₃R₂₄;

X₂₂, each independently, represents CR₃₁ or N, in which at least one X₂₂ represents N;

X₂₃, each independently, represents CR₃₂ or N;

L₁₁ to L₁₃ and L₁₅ to L₁₈, each independently, represent a single bond, a substituted or unsubstituted (C6-C30)arylene, or a substituted or unsubstituted (3- to 30-membered)heteroarylene;

L₁₄ represents a substituted or unsubstituted (C6-C30)arylene, or a substituted or unsubstituted (3- to 30-membered)heteroarylene;

R₁₁ to R₂₄, R₃₁, and R₃₂, each independently, represent hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, or a substituted or unsubstituted (C3-C30)cycloalkyl; or may be linked to an adjacent substituent to form a substituted or unsubstituted ring(s); and

aa, ff, and gg, each independently, represent an integer of 1 to 5; bb represents an integer of 1 to 7; and cc, dd, and ee, each independently, represent an integer of 1 to 4.
The organic electroluminescent compound according to claim 1, wherein Ar and R₁, each independently, are hydrogen or selected from any one of the substituents listed in the following group 2, in which at least one R₁ is selected from the following group 2:

[Group 2]

wherein

L₁ is identical to the definition of L in claim 1; and

A₁ to A₃, each independently, represent a substituted or unsubstituted (C1-C30)alkyl, or a substituted or unsubstituted (C6-C30)aryl.
The organic electroluminescent compound according to claim 1, wherein Ar and R₁, each independently, are hydrogen or selected from any one of the substituents listed in the following group 3, in which at least one R₁ is selected from the following group 3:

[Group 3]
The organic electroluminescent compound according to claim 1, wherein the compound represented by formula 1 is selected from the following:
An organic electroluminescent material comprising the organic electroluminescent compound according to claim 1.
An organic electroluminescent device comprising the organic electroluminescent compound according to claim 1.
An organic electroluminescent device according to claim 9, wherein the organic electroluminescent compound is comprised in a light-emitting layer.