PLURALITY OF HOST MATERIALS AND ORGANIC ELECTROLUMINESCENT DEVICE COMPRISING THE SAME

Info

Publication number: 20220356193
Type: Application
Filed: Mar 26, 2021
Publication Date: Nov 10, 2022
Inventors: So-Young Jung (Gyeonggi-do), Ji-Song JUN (Gyeonggi-do), Su-Hyun LEE (Gyeonggi-do), Sang-Hee CHO (Gyeonggi-do), Jin-Ri HONG (Gyeonggi-do)
Application Number: 17/214,253

Abstract

The present disclosure relates to a plurality of host materials comprising at least one first host compound and at least one second host compound, and an organic electroluminescent device comprising the same. By comprising a specific combination of the compounds wherein the first host compound is represented by formula 1 and the second host compound is represented by formula 2, it is possible to provide an organic electroluminescent device having improved driving voltage, luminous efficiency, power efficiency and/or lifetime property.

Description

Description

TECHNICAL FIELD

The present disclosure relates to a plurality of host materials and an organic electroluminescent device comprising the same.

BACKGROUND ART

A small molecular green organic electroluminescent device (OLED) was first developed by Tang, et al., of Eastman Kodak in 1987 by using TPD/ALq3 bi-layer consisting of a light-emitting layer and a charge transport layer. Thereafter, the development of OLEDs was rapidly effected and OLEDs have been commercialized. At present, OLEDs primarily use phosphorescent materials having excellent luminous efficiency in panel implementation. An OLED having high luminous efficiency and/or long lifetime characteristics is required for long time use and high resolution of a display.

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

Korean Patent Application Laying-Open No. 2020-0000329 discloses a plurality of host materials comprising a compound having a heteroaryl bonded to a phenanthrene moiety and a compound having a heteroaryl bonded to a carbazole moiety. However, said reference does not specifically disclose a specific combination of host materials claimed in the present disclosure. In addition, development of a light-emitting material having improved performances, for example, improved driving voltage, luminous efficiency, power efficiency and/or lifetime property as compared with combinations of specific compounds conventionally disclosed is still required.

DISCLOSURE OF INVENTION Technical Problem

The objective of the present disclosure is to provide an organic electroluminescent device having low driving voltage, high luminous efficiency, high power efficiency and/or excellent lifetime property by comprising a plurality of host materials including a specific combination of compounds.

Solution to Problem

The present inventors found that the above objective can be achieved by a plurality of host materials comprising at least one first host compound and at least second host compound, wherein the first host compound is represented by the following formula 1, and the second host compound is represented by the following formula 2:

wherein

B₁to B₇, each independently, are not present, or represent a substituted or unsubstituted (C5-C20) ring, in which carbon atoms of the ring may be replaced with at least one heteroatom selected from nitrogen, oxygen, and sulfur, with the proviso that at least five of B₁to B₇are present, and adjacent rings of B₁to B₇are fused with each other;

Y represents —N(L₁-(Ar₁)_n)—, —O—, —S—, or —C(R₁)(R₂)—;

L₁represents a single bond, a substituted or unsubstituted (C1-C30)alkylene, a substituted or unsubstituted (C6-C30)arylene, a substituted or unsubstituted (3- to 30-membered)heteroarylene, or a substituted or unsubstituted (C3-C30)cycloalkylene;

Ar₁represents a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, or —N(R₃)(R₄);

R₁to R₄, 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 ring(s); and

n represents an integer of 1 or 2, where if n is 2, each of Ar₁may be the same or different;

wherein

X represents —N═, —NR₃₅—, —O— or —S—;

Z represents —N═, —NR₃₆—, —O— or —S—, where if X represents —N═, Z represents —NR₃₆—, —O— or —S—, and if X represents —NR₃₅—, Z represents —N═, —O— or —S—;

HAr represents a substituted or unsubstituted (3- to 30-membered)heteroaryl;

R₃₁represents a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 30-membered)heteroaryl;

R₃₂to R₃₄, 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, 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, or -L₃-N(Ar₂)(Ar₃); or may be linked to an adjacent substituent to form a ring(s);

R₃₅and R₃₆, 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, 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, or -L₃-N(Ar₂)(Ar₃);

L₂and L₃, each independently, represent a single bond, a substituted or unsubstituted (C6-C30)arylene, or a substituted or unsubstituted (3- to 30-membered)heteroarylene;

Ar₂and Ar₃, each independently, represent hydrogen, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C2-C30)alkenyl, a substituted or unsubstituted fused ring group of a (C3-C30) aliphatic ring(s) and a (C6-C30) aromatic ring(s), a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 30-membered)heteroaryl; and

a′ represents 1, b′ and c′, each independently, represent an integer of 1 or 2, and d′ represents an integer of 1 to 4, where if each of b′, c′ and d′ is an integer of 2 or more, each of R₃₂to each of R₃₄may be the same or different.

Advantageous Effects of Invention

By comprising a plurality of host materials according to the present disclosure, an organic electroluminescent device having lower driving voltage, higher luminous efficiency, higher power efficiency and/or better lifetime property compared to conventional organic electroluminescent devices can be provided, and it is possible to produce a display system or a lighting system using the same.

MODE FOR THE INVENTION

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

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. The organic electroluminescent material may be comprised in any layer constituting an organic electroluminescent device as necessary. 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 (including a host material and a dopant material), an electron buffer material, a hole blocking material, an electron transport material, an electron injection material, etc.

The term “a plurality of organic electroluminescent materials” in the present disclosure means an organic electroluminescent material comprising a combination of at least two compounds, which may be comprised in any layer constituting an organic electroluminescent device. It may mean both a material before being comprised in an organic electroluminescent device (for example, before vapor deposition) and a material after being comprised in an organic electroluminescent device (for example, after vapor deposition). For example, a plurality of organic electroluminescent materials of the present disclosure may be a combination of at least two compounds, which may be comprised in at least one layer of 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, and an electron injection layer. The at least two compounds may be comprised in the same layer or different layers, and may be mixture-evaporated or co-evaporated, or may be individually evaporated.

The term “a plurality of host materials” in the present disclosure means an organic electroluminescent material comprising a combination of at least two host materials. It may mean both a material before being comprised in an organic electroluminescent device (for example, before vapor deposition) and a material after being comprised in an organic electroluminescent device (for example, after vapor deposition). The plurality of host materials of the present disclosure may be comprised in any light-emitting layer constituting an organic electroluminescent device. At least two compounds comprised in the plurality of host materials of the present disclosure may be comprised together in one light-emitting layer or may respectively be comprised in different light-emitting layers. When at least two host materials are comprised in one layer, for example, they may be mixture-evaporated to form a layer or may be separately co-evaporated at the same time to form a layer.

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, iso-propyl, n-butyl, iso-butyl, 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” 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, and 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, benzo[a]fluorenyl, benzo[b]fluorenyl, benzo[c]fluorenyl, dibenzofluorenyl, 2-biphenyl, 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, 11,11-dimethyl-1-benzo[a] fluorenyl, 11,11-dimethyl-2-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, 11,11-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, 11,11-diphenyl-8-benzo[c]fluorenyl, 11,11-diphenyl-9-benzo[c] fluorenyl, 11,11-diphenyl-10-benzo[c] fluorenyl, etc.

The term “(3- to 30-membered)heteroaryl” or “(3- to 50-membered)heteroaryl” is meant to be an aryl having 3 to 30 ring backbone atoms or 3 to 50 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 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, naphthobenzofuranyl, naphthobenzothiophenyl, 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-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]-benzofuranyl, 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-[2,1-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, 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, 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 alkyl, the substituted alkylene, the substituted alkenyl, the substituted aryl, the substituted arylene, the substituted heteroaryl, the substituted heteroarylene, the substituted cycloalkyl, the substituted cycloalkylene, the substituted alkoxy, the substituted trialkylsilyl, the substituted dialkylarylsilyl, the substituted alkyldiarylsilyl, the substituted triarylsilyl, the substituted fused ring of an aliphatic ring(s) and an aromatic ring(s), and the substituted ring in the formulas of the present disclosure, 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 (3- to 50-membered)heteroaryl unsubstituted or substituted with at least one of a (C1-C30)alkyl(s), a (C6-C30)aryl(s), and a di(C6-C30)arylamino(s); a (C6-C30)aryl unsubstituted or substituted with at least one of deuterium, a cyano(s), a (C1-C30)alkyl(s), a (3- to 50-membered)heteroaryl(s), a mono- or di-(C6-C30)arylamino(s), and a tri(C6-C30)arylsilyl(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-(C2-C30)alkenylamino; a mono- or di-(C6-C30)arylamino; a mono- or di-(3- to 30-membered)heteroarylamino; a (C1-C30)alkyl(C2-C30)alkenylamino; a (C1-C30)alkyl(C6-C30)arylamino; a (C1-C30)alkyl(3- to 30-membered)heteroarylamino; a (C2-C30)alkenyl(C6-C30)arylamino; a (C2-C30)alkenyl(3- to 30-membered)heteroarylamino; a (C6-C30)aryl(3- to 30-membered)heteroarylamino; 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, are at least one selected from the group consisting of deuterium; a (C1-C20)alkyl; a (3- to 30-membered)heteroaryl unsubstituted or substituted with at least one of a (C1-C20)alkyl(s) and a (C6-C25)aryl(s); a (C6-C25)aryl unsubstituted or substituted with at least one of deuterium, a (C1-C20)alkyl(s), a (3- to 30-membered)heteroaryl(s), and a di(C6-C25)arylamino(s); and a mono- or di-(C6-C25)arylamino. According to another embodiment of the present disclosure, the substituents, each independently, are at least one selected from the group consisting of deuterium; a (C1-C10)alkyl; a (5- to 26-membered)heteroaryl unsubstituted or substituted with a (C6-C18)aryl(s); a (C6-C20)aryl unsubstituted or substituted with at least one of deuterium, a (C1-C10)alkyl(s), a (5- to 26-membered)heteroaryl(s), and a di(C6-C18)arylamino(s); and a di(C6-C18)arylamino. Specifically, the substituents, each independently, may be at least one selected from the group consisting of deuterium; a methyl; a phenyl unsubstituted or substituted with at least one of deuterium, a 26-membered heteroaryl(s), and a diphenylamino(s); a naphthyl; a biphenyl; a naphthylphenyl; a phenylnaphthyl; a phenanthrenyl; a dimethylfluorenyl; a dimethylbenzofluorenyl; a terphenyl; a triphenylenyl; a pyridyl unsubstituted or substituted with a phenyl(s); a triazinyl substituted with a phenyl(s); a dibenzofuranyl; a dibenzothiophenyl; a benzonaphthothiophenyl; a carbazolyl unsubstituted or substituted with a phenyl(s); a benzocarbazolyl unsubstituted or substituted with a phenyl(s); a dibenzocarbazolyl; a 26-membered heteroaryl; and a diphenylamino.

In the formulas of the present disclosure, if a substituent is linked to an adjacent substituent to form a ring, the ring may be a substituted or unsubstituted, mono- or polycyclic, (3- to 30-membered) alicyclic or aromatic ring, or the combination thereof, which two or more adjacent substituents are linked to form. 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.

In the formulas of the present disclosure, heteroaryl and heteroarylene 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 plurality of host materials according to one embodiment of the present disclosure comprises a first host material comprising the compound represented by formula 1 and a second host material comprising the compound represented by formula 2, and may be comprised in a light-emitting layer of an organic electroluminescent device according to one embodiment of the present disclosure.

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

In formula 1, B₁to B₇, each independently, are not present, or represent a substituted or unsubstituted (C5-C20) ring, preferably a substituted or unsubstituted (C5-C13) ring, in which carbon atoms of the ring may be replaced with at least one heteroatom selected from nitrogen, oxygen, and sulfur, with the proviso that at least five of B₁to B₇are present, and adjacent rings of B₁to B₇are fused with each other. Herein, “adjacent rings of B₁to B₇are fused with each other” means that ring B₁and ring B₂, ring B₂and ring B₃, ring B₃and ring B₄, ring B₄and ring B₅, ring B₅and ring B₆, or ring B₆and ring B₇are fused with each other. According to one embodiment of the present disclosure, if any one of B₁to B₇, represents a (C6-C20)aryl, an adjacent ring may not be present, or may be a C5 ring, carbon atoms of which may be replaced with at least one heteroatom selected from nitrogen, oxygen, and sulfur. According to another embodiment of the present disclosure, B₁to B₇each independently, are not present, or represent a substituted or unsubstituted benzene ring, a substituted or unsubstituted naphthalene ring, a substituted or unsubstituted pyrrole ring, a substituted or unsubstituted furan ring, a substituted or unsubstituted thiophene ring, a substituted or unsubstituted cyclopentadiene ring, a substituted or unsubstituted fluorene ring, a substituted or unsubstituted pyridine ring, or a substituted or unsubstituted dibenzofuran ring. For example, B₁to B₇, each independently, may not be present, or may represent a benzene ring unsubstituted or substituted with a phenyl(s), a naphthyl(s) and/or a diphenyltriazinyl(s); a naphthalene ring; a cyclopentadiene ring unsubstituted or substituted with a methyl(s); a fluorene ring substituted with a methyl(s); a pyrrole ring substituted with an unsubstituted phenyl(s), a phenyl(s) substituted with at least one deuterium, a biphenyl(s) and/or a pyridiyl(s); a furan ring; a thiophene ring; a pyridine ring; or a dibenzofuran ring unsubstituted or substituted with a diphenyltriazinyl(s).

In formula 1, Y represents —N(L₁-(Ar₁)_n)—, —O—, —S—, or —C(R₁)(R₂)—. According to one embodiment of the present disclosure, Y represents —N(L₁-(Ar₁)_n)—.

L₁represents a single bond, a substituted or unsubstituted (C1-C30)alkylene, a substituted or unsubstituted (C6-C30)arylene, a substituted or unsubstituted (3- to 30-membered)heteroarylene, or a substituted or unsubstituted (C3-C30)cycloalkylene. According to one embodiment of the present disclosure, L₁represents a single bond, a substituted or unsubstituted (C6-C25)arylene, or a substituted or unsubstituted (3- to 30-membered)heteroarylene. According to another embodiment of the present disclosure, L₁represents a single bond, an unsubstituted (C6-C18)arylene, or an unsubstituted (5- to 25-membered)heteroarylene. For example, L₁may be a single bond, a phenylene, a naphthylene, a biphenylene, a pyridylene, a pyrimidinylene, a triazinylene, a quinoxalinylene, a quinazolinylene, a dibenzofuranylene, a benzofuropyrimidinylene, a benzothienopyrimidinylene, an indolopyrimidinylene, or a benzoquinoxalinylene.

Ar₁represents a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, or —N(R₃)(R₄). According to one embodiment of the present disclosure, Ar₁represents a substituted or unsubstituted (C6-C25)aryl, a substituted or unsubstituted (5- to 25-membered)heteroaryl, or —N(R₃)(R₄). According to another embodiment of the present disclosure, Ar₁represents a (C6-C25)aryl unsubstituted or substituted with at least one of deuterium, a (C1-C6)alkyl(s), and a (3- to 30-membered)heteroaryl(s); a (5- to 25-membered)heteroaryl unsubstituted or substituted with at least one of deuterium, a (C6-C18)aryl(s), and a (3- to 30-membered)heteroaryl(s); or —N(R₃)(R₄). For example, Ar₁may be an unsubstituted phenyl, a phenyl substituted with at least one deuterium, a phenyl substituted with a 26-membered heteroaryl(s), a naphthyl, a biphenyl, a fluorenyl substituted with a methyl(s), a spirobifluorenyl, a terphenyl, a triphenylenyl, a pyridyl unsubstituted and substituted with a phenyl(s), a pyrmidinyl substituted with a phenyl(s), a substituted triazinyl, a substituted quinoxalinyl, a substituted quinazolinyl, a benzoquinoxalinyl substituted with a phenyl(s), a carbazolyl, a dibenzofuranyl, a dibenzothiophenyl, a benzofuropyrimidinyl substituted with a phenyl(s), a benzothienopyrimidinyl substituted with a phenyl(s), an indolopyrimidinyl substituted with a phenyl(s), or —N(R₃)(R₄). The substituents of the substituted triazinyl, the substituted quinoxalinyl, and the substituted quinazolinyl, each independently, may be at least one selected from the group consisting of a phenyl unsubstituted or substituted with at least one of deuterium and a 26-membered heteroaryl(s), a naphthyl, a biphenyl, a terphenyl, a dibenzofuranyl, a pyridyl substituted with a phenyl(s), a dimethylfluorenyl, and a dibenzothiophenyl.

R₁to R₄, 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 ring(s). According to one embodiment of the present disclosure, R₁to R₄, each independently, represent hydrogen, deuterium, a substituted or unsubstituted (C1-C20)alkyl, or a substituted or unsubstituted (C6-C25)aryl. According to another embodiment of the present disclosure, R₁and R₂, each independently, represent an unsubstituted (C1-C10)alkyl, and R₃and R₄, each independently, represent an unsubstituted (C6-C18)aryl. For example, R₁and R₂may be a methyl, and R₃and R₄may be a phenyl.

n represents an integer of 1 or 2, where if n is 2, each of Ar₁may be the same or different

Formula 1 may be represented by at least one of the following formulas 1-1 to 1-4.

In formulas 1-1 to 1-4, Y₁, Y₂, Y₃, and Y₄, each independently, are the same as the definition of Y in formula 1, where if a plurality of Ar₁'s are present, each of Ar₁may be the same or different; X₁to X₁₂, each independently, represent —N═ or —C(R_a)═; R_a, 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, or a substituted or unsubstituted (C3-C30)cycloalkyl; or adjacent R_a's may be linked to each other to form a ring(s), where if a plurality of R_a's are present, each of R_amay be the same or different.

According to one embodiment of the present disclosure, R_arepresents hydrogen, deuterium, a substituted or unsubstituted (C6-C25)aryl, or a substituted or unsubstituted (5- to 25-membered)heteroaryl; or adjacent R_a's may be linked to each other to form a ring(s). According to another embodiment of the present disclosure, R_arepresents hydrogen, an unsubstituted (C6-C18)aryl, or a (5- to 25-membered)heteroaryl substituted with a (C6-C18)aryl(s); or adjacent R_a's may be linked to each other to form a benzene ring(s), an indene ring(s) substituted with a methyl(s), or a benzofuran ring(s) unsubstituted or substituted with a diphenyltriazinyl(s).

In any one of formulas 1-1 to 1-4, at least one of Ar₁(s) and R_a(s), each independently, may be at least one selected from those listed in the following group 1.

In group 1, D1 and D2, each independently, represent a benzene ring or a naphthalene ring; X₂₁represents O, S, NR₅, or C(R₆)(R₇); X₂₂, each independently, represents CR or N, with the proviso that at least one of X₂₂represents N; X₂₃, each independently, represents CR₉or N; L₁₁to L₁₈, each independently, represent a single bond, a substituted or unsubstituted (C6-C30)arylene, or a substituted or unsubstituted (3- to 30-membered)heteroarylene; R₁₁to R₂₁and R₅to R₉, 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 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.

According to one embodiment of the present disclosure, D1 may be a benzene ring; X₂₁may be O, S, or C(R₆)(R₇); L₁₁to L₁₈, each independently, may be a single bond; R₁₁to R₂₁and R₅to R₉, each independently, may be hydrogen, deuterium, a substituted or unsubstituted (C1-C20)alkyl, a substituted or unsubstituted (C6-C25)aryl, or a substituted or unsubstituted (5- to 25-membered)heteroaryl, or may be linked to an adjacent substituent to form a ring(s); and aa, bb, ff, and gg, each independently, may be an integer of 1 to 5, and cc, dd, and ee, each independently, may be an integer of 1 to 4. For example, R₁₁may be hydrogen, deuterium, a phenyl, a biphenyl, or a 26-membered heteroaryl; R₁₂may be hydrogen, or adjacent R₁₂'s may be linked to each other to form a benzene ring(s); R₁₃, R₁₈, and R₁₇may be hydrogen; R₁₈and R₁₉may be hydrogen or a phenyl; R₂₁may be phenyl; R₆and R₇may be a methyl; R₈may be hydrogen, a phenyl, a biphenyl, a dibenzofuranyl, or a dibenzothiophenyl, or adjacent R₈'s may be linked to each other to form a benzene ring(s); R₉may be hydrogen, an unsubstituted phenyl, a phenyl substituted with at least one deuterium, a phenyl substituted with a 26-membered heteroaryl(s), a naphthyl, a biphenyl, a dimethylfluorenyl, a terphenyl, a pyridyl substituted with a phenyl(s), a dibenzofuranyl, or a dibenzothiophenyl; and aa may be an integer of 1 or 5, bb may be an integer of 1 or 4, and cc may be 1.

In any one of formulas 1-1 to 1-4, at least one of Ar₁(s) and R_a(s), each independently, may be at least one selected from those listed in the following group 2.

In group 2, L represents a single bond, a substituted or unsubstituted (C1-C30)alkylene, a substituted or unsubstituted (C6-C30)arylene, a substituted or unsubstituted (3- to 30-membered)heteroarylene, or a substituted or unsubstituted (C3-C30)cycloalkylene; and A₁to A₃, each independently, represent a substituted or unsubstituted (C1-C30)alkyl, or a substituted or unsubstituted (C6-C30)aryl. According to one embodiment of the present disclosure, L represents a single bond, a substituted or unsubstituted (C6-C25)arylene, or a substituted or unsubstituted (3- to 25-membered)heteroarylene; and A₁to A₃, each independently, represent a substituted or unsubstituted (C1-C20)alkyl, or a substituted or unsubstituted (C6-C25)aryl. A₁and A₂may be the same or different. For example, A₁and A₂, each independently, may be a methyl or a phenyl.

In any one of formulas 1-1 to 1-4, at least one of Ar₁(s) and R_a(s), each independently, may be at least one selected from those listed in the following group 3.

Hereinafter, the compound represented by formula 2 will be described in more detail.

According to one embodiment of the present disclosure, formula 2 may be represented by at least one selected from the following formulas 2-1 to 2-8.

In formulas 2-1 to 2-8, X, Z, HAr, R₃₁to R₃₆, L₂and a′ to d′ are as defined in formula 2; Z₁to Z₅and Z₁₁to Z₁₇, each independently, represent N or CR₃₇; and R₃₇, each independently, is the same as the definition of R₃₂of formula 2.

According to one embodiment of the present disclosure, R₃₇, each independently, represents hydrogen, deuterium, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C25)aryl, or a substituted or unsubstituted (5- to 25-membered)heteroaryl. According to another embodiment of the present disclosure, R₃₇, each independently, represents hydrogen; deuterium; a (C6-C18)aryl unsubstituted or substituted with at least one of a (C1-C10)alkyl(s) and a di(C6-C18)arylamino(s); or a (5- to 20-membered)heteroaryl unsubstituted or substituted with a (C6-C18)aryl(s). For example, R₃₇, each independently, may be hydrogen, a phenyl unsubstituted or substituted with a diphenylamino(s), a naphthyl, a biphenyl, a dimethylfluorenyl, a dimethylbenzofluorenyl, a dibenzothiophenyl, a dibenzofuranyl, a benzonaphthothiophenyl, a phenylcarbazolyl, or a phenylbenzocarbazolyl.

In formula 2, X represents —N═, —NR₃₅—, —O— or —S—, and Z represents —N═, —NR₃₆—, —O— or —S—, where if X represents —N═, Z represents —NR₃₆—, —O— or —S—, and if X represents —NR₃₅—, Z represents —N═, —O— or —S—. According to an embodiment of the present disclosure, X represents —N═, —NR₃₅—, —O— or —S—, and Z represents —N═, —NR₃₆—, —O— or —S—, with the proviso that at least one of X and Z represents —N═.

R₃₅and R₃₆, 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, 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, or -L₃-N(Ar₂)(Ar₃). According to one embodiment of the present disclosure, R₃₅and R₃₆, each independently, represent a substituted or unsubstituted (C1-C20)alkyl, a substituted or unsubstituted (C6-C25)aryl, or a substituted or unsubstituted (5- to 25-membered)heteroaryl. According to another embodiment of the present disclosure, R₃₅and R₃₆, each independently, represent an unsubstituted (C6-C18)aryl. For example, R₃₅and R₃₆may be a phenyl.

In formula 2, HAr represents a substituted or unsubstituted (3- to 30-membered)heteroaryl. According to one embodiment of the present disclosure, HAr represents a substituted or unsubstituted (3- to 30-membered)heteroaryl containing a nitrogen atom(s). According to another embodiment of the present disclosure, HAr represents a substituted or unsubstituted (5- to 25-membered)heteroaryl containing a nitrogen atom(s). According to further embodiment of the present disclosure, HAr represents a (5- to 20-membered)heteroaryl containing a nitrogen atom(s), substituted with a (5- to 25-membered)heteroaryl(s) and/or a (C6-C25)aryl(s). Specifically, HAr may be a substituted or unsubstituted triazinyl, a substituted or unsubstituted pyridyl, a substituted or unsubstituted pyrimidinyl, a substituted or unsubstituted quinazolinyl, a substituted or unsubstituted benzoquinazolinyl, a substituted or unsubstituted quinoxalinyl, a substituted or unsubstituted benzoquinoxalinyl, a substituted or unsubstituted quinolyl, a substituted or unsubstituted benzoquinolyl, a substituted or unsubstituted isoquinolyl, a substituted or unsubstituted benzoisoquinolyl, a substituted or unsubstituted triazolyl, a substituted or unsubstituted pyrazolyl, a substituted or unsubstituted naphthyridinyl, a substituted or unsubstituted benzothienopyrimidinyl. For example, HAr may be a substituted triazinyl, a substituted pyrimidinyl, a substituted quinoxalinyl, a substituted quinazolinyl, or a substituted naphthyridinyl. The substituents of the substituted triazinyl, the substituted pyrimidinyl, the substituted quinoxalinyl, the substituted quinazolinyl, and the substituted naphthyridinyl may be at least one of a phenyl unsubstituted or substituted with a diphenylamino(s), a naphthyl, a biphenyl, a dimethylfluorenyl, a dimethylbenzofluorenyl, a dibenzothiophenyl, a dibenzofuranyl, a benzonaphthothiophenyl, a phenylcarbazolyl, and a phenylbenzocarbazolyl.

In formula 2, R₃₁represents a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 30-membered)heteroaryl. According to one embodiment of the present disclosure, R₃₁represents a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (5- to 25-membered)heteroaryl. According to another embodiment of the present disclosure, R₃₁represents a (C6-C29)aryl unsubstituted or substituted with at least one of a (C1-C10)alkyl(s) and a (C6-C18)aryl(s); or a (5- to 25-membered)heteroaryl unsubstituted or substituted with a (C6-C18)aryl(s). For example, R₃₁may be a phenyl, a naphthyl, a phenylnaphthyl, a biphenyl, a dimethylfluorenyl, a dimethylbenzofluorenyl, a spirobifluorenyl, a spiro[fluoren-benzofluoren]yl, a phenylcarbazolyl, a phenylbenzocarbazolyl, a dibenzofuranyl, or a dibenzothiophenyl.

In formula 2, R₃₂to R₃₄, 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, 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, or -L₃-N(Ar₂)(Ar₃); or may be linked to an adjacent substituent to form a ring(s). For example, R₃₂to R₃₄may represent hydrogen.

In formula 2, L₂and L₃, each independently, represent a single bond, a substituted or unsubstituted (C6-C30)arylene, or a substituted or unsubstituted (3- to 30-membered)heteroarylene. According to one embodiment of the present disclosure, L₂and L₃, each independently, represent a single bond, a substituted or unsubstituted (C6-C25)arylene, or a substituted or unsubstituted (5- to 25-membered)heteroarylene. According to another embodiment of the present disclosure, L₂and L₃, each independently, represent a single bond, an unsubstituted (C6-C18)arylene, or an unsubstituted (5- to 20-membered)heteroarylene. For example, L₂and L₃, each independently, may be a single bond, a phenylene, or a pyridylene.

In formula 2, Ar₂and Ar₃, each independently, represent hydrogen, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C2-C30)alkenyl, a substituted or unsubstituted fused ring group of a (C3-C30) aliphatic ring(s) and a (C6-C30) aromatic ring(s), a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 30-membered)heteroaryl.

In formula 2, a′ represents 1, b′ and c′, each independently, represent an integer of 1 or 2, and d′ represents an integer of 1 to 4, where if each of b′, c′ and d′ is an integer of 2 or more, each of R₃₂to each of R₃₄may be the same or different.

The compound represented by formula 1 may be at least one selected from the following compounds, but is not limited thereto.

The compound represented by formula 2 may be at least one selected from the following compounds, but is not limited thereto.

The combination of at least one of compounds C-1 to C-300 and at least one of compounds C2-1 to C2-125 may be used in an organic electroluminescent device.

The compound represented by formula 1 of the present disclosure may be produced by a synthetic method known to one skilled in the art, and for example, according to the following reaction schemes 1 to 4, but is not limited thereto:

In reaction schemes 1 to 4, Y₁to Y₄, and X₁to X₁₂are as defined in formulas 1-1 to 1-4.

Although illustrative synthesis examples of the compound represented by formula 1 of the present disclosure are 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, an 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 SN₁substitution reaction, an SN₂substitution reaction, a Phosphine-mediated reductive cyclization reaction, etc., and the reactions above proceed even when substituents which are defined in formula 1, but are not specified in the specific synthesis examples, are bonded.

The compound represented by formula 2 of the present disclosure may be produced by a synthetic method known to one skilled in the art, and for example, according to the methods disclosed in Korean Patent Application Laying-Open No. 2020-0000329 (published on Jan. 2, 2020), etc.

In addition, the non-deuterated analogues of the compound represented by formula 2 can be prepared by known coupling and substitution reactions. Also, the non-deuterated analogues may be prepared in a similar manner by using deuterated precursor materials, or more generally may be prepared by treating the non-deuterated compound with a deuterated solvent or D6-benzene in the presence of an H/D exchange catalyst such as a Lewis acid, e.g., aluminum trichloride or ethyl aluminum chloride, a trifluoromethanesulfonic acid, or a trifluoromethanesulfonic acid-D. In addition, the degree of deuteration can be controlled by changing the reaction conditions such as the reaction temperature. For example, the number of deuterium in formula 2 can be controlled by adjusting the reaction temperature and time, the equivalent of the acid, etc.

The organic electroluminescent device according to the present disclosure may comprise an anode, a cathode, and at least one organic layer between the anode and cathode in which the organic layer may comprise a plurality of organic electroluminescent materials, including the compound represented by formula 1 as the first organic electroluminescent material, and the compound represented by formula 2 as the second organic electroluminescent material. According to one embodiment of the present disclosure, the organic electroluminescent device according to the present disclosure may comprise an anode, a cathode, and at least one light-emitting layer between the anode and cathode in which the light-emitting layer may comprise the compound represented by formula 1 and the compound represented by formula 2.

The light-emitting layer includes a host and a dopant, in which the host includes a plurality of host materials and the compound represented by formula 1 may be included as the first host compound of the plurality of host materials, and the compound represented by formula 2 may be included as the second host compound of the plurality of host materials. The weight ratio of the first host compound and the second host compound is about 1:99 to about 99:1, preferably about 10:90 to about 90:10, more preferably about 30:70 to about 70:30, even more preferably about 40:60 to about 60:40, and most preferably about 50:50.

Herein, the light-emitting layer is a layer from which light is emitted, and may be a single layer or a multi-layer of which two or more layers are stacked. All of the first host material and the second host material may be included in one layer, or the first host material and the second host material may be included in respective different light-emitting layers. According to one embodiment of the present disclosure, the doping concentration of the dopant compound with respect to the host compound in the light-emitting layer may be less than 20 wt %.

The organic electroluminescent device of the present disclosure 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 injection layer, an interlayer, an electron buffer layer, a hole blocking layer, and an electron blocking layer. According to one embodiment of the present disclosure, the organic electroluminescent device of the present disclosure may further comprise an amine-based compound besides the plurality of host materials of the present disclosure as at least one of a hole injection material, a hole transport material, a hole auxiliary material, a light-emitting material, a light-emitting auxiliary material, and an electron blocking material. Further, according to one embodiment of the present disclosure, the organic electroluminescent device of the present disclosure may further comprise an azine-based compound besides the plurality of host materials of the present disclosure as at least one of an electron transport material, an electron injection material, an electron buffer material, and a hole blocking material.

The plurality of host materials according to 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) or YG (yellowish green), B (blue) light-emitting units. In addition, the plurality of host materials according to one embodiment of the present disclosure may also be used in an organic electroluminescent device comprising a quantum dot (QD).

A hole injection layer, a hole transport layer, an electron blocking layer, or a combination thereof can 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. Further, the hole injection layer may be doped with a p-dopant. 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. The hole transport layer or the electron blocking layer may also be multilayers, wherein each of the multilayers may use a plurality of compounds.

An electron buffer layer, a hole blocking layer, an electron transport layer, an electron injection layer, or a combination thereof can be used between the light-emitting layer and the cathode. The electron buffer layer may be multilayers in order to control the electron injection 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. In addition, the electron injection layer may be doped with an n-dopant.

The dopant comprised in the organic electroluminescent device of the present disclosure may be at least one phosphorescent or fluorescent dopant, and is preferably phosphorescent dopant. The phosphorescent dopant material applied to the organic electroluminescent device of the present disclosure is not particularly 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 comprise 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:

R₁₀₀to R₁₀₃, each independently, represent hydrogen, deuterium, a halogen, a (C1-C30)alkyl unsubstituted or substituted with deuterium and/or 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 substituent to form a ring(s), e.g., a substituted or unsubstituted, quinoline, isoquinoline, benzofuropyridine, benzothienopyridine, indenopyridine, benzofuroquinoline, benzothienoquinoline, or indenoquinoline, together with pyridine;

R₁₀₄to R₁₀₇, each independently, represent hydrogen, deuterium, a halogen, a (C1-C30)alkyl unsubstituted or substituted with deuterium and/or 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 an adjacent substituent to form a ring(s), e.g., a substituted or unsubstituted, naphthalene, fluorene, dibenzothiophene, dibenzofuran, indenopyridine, benzofuropyridine, or benzothienopyridine, together with benzene;

R₂₀₁to R₂₂₀, each independently, represent hydrogen, deuterium, a halogen, a (C1-C30)alkyl unsubstituted or substituted with deuterium and/or a halogen(s), a substituted or unsubstituted (C3-C30)cycloalkyl, or a substituted or unsubstituted (C6-C30)aryl; or may be linked to an adjacent substituent to form a ring(s); and

s represents an integer of 1 to 3.

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

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 methods, etc., or wet film-forming methods such as ink jet printing, nozzle printing, slot coating, spin coating, dip coating, flow coating methods, etc., can be used.

When using a wet film-forming method, a thin film can be formed by dissolving or diffusing materials forming each layer into any suitable solvent such as ethanol, chloroform, tetrahydrofuran, dioxane, etc. The solvent can be any solvent where the materials forming each layer can be dissolved or diffused, and where there are no problems in film-formation capability.

The first and the second host compounds of the present disclosure may be film-formed by the above-listed methods, commonly by a co-evaporation process or a mixture-evaporation process. The co-evaporation is a mixed deposition method in which two or more materials are placed in a respective individual crucible source and a current is applied to both cells at the same time to evaporate the materials. The mixture-evaporation is a mixed deposition method in which two or more materials are mixed in one crucible source before evaporating them, and a current is applied to the cell to evaporate the materials. Further, if the first and the second host compounds are present in the same layer or different layers in an organic electroluminescent device, the two host compounds may individually form films. For example, the second host compound may be deposited after depositing the first host compound.

The present disclosure may provide a display device by using the plurality of host materials including the compound represented by formula 1 and the compound represented by formula 2. That is, by using the plurality of host materials of the present disclosure, it is possible to manufacture a display system or a lighting system. Specifically, by using the plurality of host materials of the present disclosure, a display system, for example, for white organic light emitting devices, smart phones, tablets, notebooks, PCs, TVs, or cars; or a lighting system, for example an outdoor or indoor lighting system, can be produced.

Hereinafter, the preparation method of the compounds according to the present disclosure and the properties thereof, and the properties of an organic electroluminescent device comprising the plurality of host materials of the present disclosure will be explained in detail with reference to the representative compounds of the present disclosure. However, the present disclosure is not limited by the following examples.

Example 1: Preparation of Compound C-1

Synthesis of Compound 1-1

(9-phenyl-9H-carbazol-4-yl)boronic acid (96 g, 334.3 mmol), 2-bromo-1-chloro-3-nitrobenzene (71.8 g, 304 mmol), Pd₂(dba)₃(15 g, 16.71 mmol), S-Phos (10.9 g, 26.76 mmol), and K₃PO₄(315 g, 1.64 mol) were dissolved in 1500 mL of toluene in a flask, and the mixture was stirred at 130° C. for 4 hours. After completion of the reaction, an organic layer was extracted with ethyl acetate, and the residual moisture was removed using magnesium sulfate. The residue was dried, and separated by column chromatography to obtain compound 1-1 (67 g, yield: 56.6%).

Synthesis of Compound 1-2

Compound 1-1 (23.5 g, 58.9 mmol), (2-chlorophenyl)boronic acid (18.4 g, 117.8 mmol), Pd₂(dba)₃(2.7 g, 2.95 mmol), S-Phos (2.4 g, 5.89 mmol), and K₃PO₄(63 g, 294.5 mmol) were dissolved in 300 mL of toluene in a flask, and the mixture was stirred at 130° C. for 12 hours. After completion of the reaction, an organic layer was extracted with ethyl acetate, and the residual moisture was removed using magnesium sulfate. The residue was dried, and separated by column chromatography to obtain compound 1-2 (14 g, yield: 50%).

Synthesis of Compound 1-3

Compound 1-2 (13 g, 27.4 mmol), and triphenylphosphine (21.5 g, 82.1 mmol) were dissolved in 140 mL of o-DCB in a flask, and the mixture was stirred at 220° C. for 7 hours. After completion of the reaction, the reaction mixture was removed by distillation, and separated by column chromatography to obtain compound 1-3 (4 g, yield: 32%).

Synthesis of Compound 1-4

Compound 1-3 (10 g, 22.5 mmol), Pd(OAc)₂(505 mg, 2.25 mmol), Pcy₃-HBF₄(1.63 g, 4.5 mmol), and Cs₂CO₃(22 g, 67.5 mmol) were dissolved in 113 mL of o-xylene in a flask, and the mixture was stirred at 160° C. for 4 hours. After completion of the reaction, an organic layer was extracted with ethyl acetate, and the residual moisture was removed using magnesium sulfate. The residue was dried, and separated by column chromatography to obtain compound 1-4 (1 g, yield: 11%).

Synthesis of Compound C-1

Compound 1-4 (4.5 g, 11.06 mmol), 2-chloro-3-phenylquinoxaline (4 g, 16.6 mmol), 4-dimethylaminopyridine (DMAP) (67 mg, 0.553 mmol), and Cs₂CO₃(10.8 g, 331.8 mmol) were dissolved in 60 mL of dimethylsulfoxide (DMSO) in a flask, and the mixture was refluxed at 140° C. for 4 hours. After completion of the reaction, an organic layer was extracted with ethyl acetate, and the residual moisture was removed using magnesium sulfate. The residue was dried, and separated by column chromatography to obtain compound C-1 (2.5 g, yield: 37%).

Compound MW M.P. C-1 610.22 246° C.

Example 2: Preparation of Compound C-29

Compound 1-4 (4 g, 9.84 mmol), 3-bromo-1,1′:2′,1″-terphenyl (3.65 g, 11.8 mmol), Pd₂(dba)₃(448 mg, 0.492 mmol), S-Phos (448 mg, 0.984 mmol), and NaOtBu (2.84 g, 29.52 mmol) were dissolved in 50 mL of o-xylene in a flask, and the mixture was stirred at 170° C. for 4 hours. After completion of the reaction, an organic layer was extracted with ethyl acetate, and the residual moisture was removed using magnesium sulfate. The residue was dried, and separated by column chromatography to obtain compound C-29 (1.5 g, yield: 24%).

Compound MW M.P. C-29 643.78 282° C.

Example 3: Preparation of Compound C-196

Synthesis of Compound 3-1

Compound A (60 g, 283 mmol), Compound B (100 g, 424 mmol), tetrakis(triphenylphosphine)palladium (16.3 g, 14.1 mmol), cesium carbonate (276 g, 849 mmol), 1400 mL of toluene, 350 mL of ethanol and 350 mL of distilled water were added into a reaction vessel, and the mixture was stirred at 130° C. for 12 hours. After completion of the reaction, the reaction mixture was cooled to room temperature, and extracted with ethyl acetate. The extracted organic layer was dried with magnesium sulfate, and the solvent was removed by rotary evaporator. Then, the residue was separated by column chromatography to obtain compound 3-1 (38 g, yield: 41%).

Synthesis of Compound 3-2

Compound 3-1 (38 g, 117 mmol), phenylboronic acid (35 g, 234 mmol), tris(dibenzylindeneacetone)dipalladium (5.3 g, 5.86 mmol). S-Phos (4.8 g, 11.7 mmol), tripotassium phosphate (62 g, 293 mmol), and 600 mL of toluene were added into a reaction vessel, and the mixture was stirred under reflux for 2 hours. After completion of the reaction, the reaction mixture was washed with distilled water, and extracted with ethyl acetate. The extracted organic layer was dried with magnesium sulfate, and the solvent was removed by rotary evaporator. Then, the residue was separated by column chromatography to obtain compound 3-2 (31 g, yield: 67%).

Synthesis of Compound 3-3

Compound 3-2 (21 g, 53.7 mmol), triphenylphosphite (70 mL, 268 mmol), and 180 mL of dichlorobenzene (DCB) were added into a reaction vessel, and the mixture was stirred at 200° C. for 12 hours. After completion of the reaction, the reaction mixture was distilled under reduced pressure to remove DCB, and washed with distilled water and extracted with ethyl acetate. The extracted organic layer was dried with magnesium sulfate, and the solvent was removed by rotary evaporator. Then, the residue was separated by column chromatography to obtain compound 3-3 (10 g, yield: 55%).

Synthesis of Compound 3-4

Compound 3-3 (6.6 g, 17.9 mmol), palladium (II) acetate (0.2 g, 0.89 mmol), PCy₃-BF₄(1.3 g, 3.58 mmol), cesium carbonate (17 g, 53.7 mmol), and 90 mL of o-xylene were added into a reaction vessel, and the mixture was stirred under reflux at 160° C. for 4 hours. After completion of the reaction, the reaction mixture was washed with distilled water, and extracted with ethyl acetate. The extracted organic layer was dried with magnesium sulfate, and the solvent was removed by rotary evaporator. Then, the residue was separated by column chromatography to obtain compound 3-4 (1.8 g, yield: 32%).

Synthesis of Compound C-196

Compound 3-4 (1.8 g, 5.43 mmol), 2-(3-bromophenyl)-4,6-diphenyl-1,3,5-triazine (2.3 g, 5.97 mmol), tris(dibenzylindeneacetone)dipalladium (0.2 g, 0.27 mmol), tri-tert-butylphosphine (0.3 mL, 0.54 mmol), sodium tert-butoxide (1.3 g, 13.5 mmol), and 30 mL of toluene were added into a reaction vessel, and the mixture was stirred under reflux for 3 hours. After completion of the reaction, the reaction mixture was washed with distilled water, and extracted with ethyl acetate. The extracted organic layer was dried with magnesium sulfate, and the solvent was removed by rotary evaporator. Then, the residue was separated by column chromatography to obtain compound C-196 (3.3 g, yield: 95%).

Compound MW UV PL M.P. C-196 638.21 410 nm 522 nm 240° C.

Example 4: Preparation of Compound C-36

Compound 1-4 (4.0 g, 9.84 mmol), 4-bromo-N,N-diphenylaniline (3.2 g, 9.84 mmol), Pd₂(dba)₃(0.45 g, 0.5 mmol), s-phos (0.4 g, 0.98 mmol), and NaOtBu (1.9 g, 19.7 mmol) were dissolved in 50 mL of o-xylene in a flask, and the mixture was stirred under reflux for 5 hours. After completion of the reaction, an organic layer was extracted with ethyl acetate, and separated by column chromatography to obtain compound C-36 (2.67 g, yield: 42%).

Compound MW M.P. C-36 649.78 312° C.

Example 5: Preparation of Compound C-32

Compound 1-4 (4.0 g, 9.84 mmol), 2-bromodibenzo[b,d]furan (1.7 g, 9.84 mmol), Pd₂(dba)₃(0.45 g, 0.5 mmol), s-phos (0.4 g, 0.98 mmol), and NaOtBu (1.9 g, 19.7 mmol) were dissolved in 50 mL of o-xylene in a flask, and the mixture was stirred under reflux for 5 hours. After completion of the reaction, an organic layer was extracted with ethyl acetate, and separated by column chromatography to obtain compound C-32 (1.68 g, yield: 30%).

Compound MW M.P. C-32 572.65 291° C.

Example 6: Preparation of Compound C2-86

Compound A (CAS: 2085325-18-2, 4.0 g, 9.5 mmol), 2-chloro-3-phenylquinoxaline (2.8 g, 11.4 mmol), tetrakis(triphenylphosphine)palladium (Pd(PPh₃)₄) (0.5 g, 0.5 mmol), potassium carbonate (K₂CO₃) (2.0 g, 19 mmol), 30 mL of toluene, 7 mL of EtOH, and 10 mL of water were added into a reaction vessel, and the mixture was stirred under reflux for one day. After completion of the reaction, the reaction mixture was cooled to room temperature, filtered by cellite with methylene chloride (MC), distilled under reduced pressure, and then separated by column chromatography with methylene chloride/hexane (MC/Hex) to obtain compound C2-86 (2.7 g, yield: 57%).

Compound MW M.P. C2-86 499.6 266° C.

Example 7: Preparation of Compound C2-125

Compound A (23.8 g, 56.6 mmol), 2-chloro-4-(naphthalen-1-yl)-6-phenyl-1,3,5-triazine (15.0 g, 47.2 mmol), Pd(PPh₃)₄(2.72 g, 2.36 mmol), K₂CO₃(16.3 g, 118 mmol), 240 mL of toluene, 60 mL of EtOH, and 60 mL of distilled water were added into a reaction vessel, and the mixture was stirred under reflux for 2 hours. After completion of the reaction, the reaction mixture was cooled to room temperature, and filtered by silica gel. Then, an organic layer was distilled under reduced pressure, and recrystallized with toluene to obtain compound C2-125 (13.8 g, yield: 51%).

Compound MW M.P. C2-125 576.6 231° C.

Example 8: Preparation of Compound C2-116

Compound A (4.0 g, 9.5 mmol), 2-([1,1′-biphenyl]-3-yl)-4-chloro-6-phenyl-1,3,5-triazine (3.9 g, 11.4 mmol), Pd(PPh₃)₄(0.5 g, 0.5 mmol), K₂CO₃(2.6 g, 19 mmol), 30 mL of toluene, 7 mL of EtOH, and 10 mL of distilled water were added into a reaction vessel, and the mixture was stirred under reflux for 6 hours. After completion of the reaction, the reaction mixture was cooled to room temperature, and stirred at room temperature. The solid obtained by adding MeOH was filtered under reduced pressure, and separated by column chromatography with MC to obtain compound C2-116 (4.6 yield: 80%).

Compound MW M.P. C2-116 602.7 227° C.

Example 9: Preparation of Compound C2-120

Compound A (3.0 g, 7.1 mmol), 2-chloro-4-(dibenzo[b,d]furan-1-yl)-6-phenyl-1,3,5-triazine (3.4 g, 9.26 mmol), Pd(PPh₃)₄(0.4 g, 0.36 mmol), K₂CO₃(2.0 g, 14 mmol). 36 mL of toluene, 8 mL of EtOH, and 12 mL of distilled water were added into a reaction vessel, and the mixture was stirred under reflux for 6 hours. After completion of the reaction, the reaction mixture was cooled to room temperature, and stirred at room temperature. The solid obtained by adding MeOH was filtered under reduced pressure, and separated by column chromatography with MC to obtain compound C2-120 (3.3 g, yield: 75%).

Compound MW M.P. C2-120 616.7 282° C.

Device Examples 1 to 3: Producing an OLED According to the Present Disclosure

OLEDs according to the present disclosure were produced. 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 and isopropyl alcohol, sequentially, and then was stored in isopropyl alcohol. The ITO substrate was then mounted on a substrate holder of a vacuum vapor deposition apparatus. Compound HI-1 shown in Table 2 as a first hole injection compound was introduced into a cell of the vacuum vapor deposition apparatus, and compound HT-1 shown in Table 2 was introduced into another cell of the vacuum vapor deposition apparatus. The two materials were evaporated at different rates, and compound HI-1 was deposited in a doping amount of 3 wt % based on the total amount of compound HI-1 and compound HT-1 to form a hole injection layer having a thickness of 10 nm on the ITO substrate. Next, compound HT-1 was deposited on the hole injection layer to form a first hole transport layer having a thickness of 80 nm. 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 layer and the hole transport layers, a light-emitting layer was formed thereon as follows: The first host compound and the second host compound shown in Table 1 below were introduced into two cells of the vacuum vapor depositing apparatus as hosts, and compound D-71 was introduced into another cell as a dopant. The two host materials were evaporated at a rate of 1:1 and the dopant material was simultaneously evaporated at a different rate, and the dopant was deposited in a doping amount of 3 wt % based on the total amount of the hosts and the dopant to form a light-emitting layer having a thickness of 40 nm on the second hole transport layer. Compound ETL-1 and compound EIL-1 were evaporated in a weight ratio of 50:50 to form an electron transport layer having a thickness of 35 nm on the light-emitting layer. After depositing compound EIL-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. All the materials used for producing the OLED were purified by vacuum sublimation at 10⁻⁸torr.

Comparative Examples 1 to 3: Producing an OLED Comprising a Comparative Compound as a Host

OLEDs were produced in the same manner as in Device Example 1, except that the compound shown in Table 1 below was used alone as a first host or a second host.

The driving voltage, luminous efficiency, and light-emitting color 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 (lifetime; T95) of the OLEDs produced in Device Examples 1 to 3, and Comparative Examples 1 to 3 are provided in Table 1 below.

TABLE 1 Life- Driving Luminous Light- time Fist Second Voltage Efficiency Emitting (T95, Host Host (V) (cd/A) Color hr) Comparative C-29 — 4.7 5.8 Red 9.3 Example 1 Comparative — C2-120 3.5 30.8 Red 55 Example 2 Comparative — C2-116 3.2 28.0 Red 33.9 Example 3 Device C-29 C2-120 3.0 35.3 Red 551 Example 1 Device C-32 C2-120 3.1 35.4 Red 563 Example 2 Device C-32 C2-116 3.0 35.1 Red 322 Example 3

From Table 1 above, it can be confirmed that the OLEDs comprising the plurality of host materials according to the present disclosure as host materials have improved driving voltage, luminous efficiency, and/or lifespan property, compared to the conventional OLED. Without wishing to be bound by theory, it is considered that by using the compound represented by formula 1 of the present disclosure in combination with the compound represented by formula 2 of the present disclosure, the HOMO (highest occupied molecular orbital) energy level increases compared to the case when using the conventional compound, which is a carbazole derivative, resulting in increase of the hole mobility. Thus, the hole injection from a hole transport layer becomes easier, and the balance between hole and electron and the formation of exciton may be improved, thereby improving the driving voltage, luminous efficiency and/or lifetime property of an OLED.

The compounds used in the Device Examples and the Comparative Examples are shown in Table 2 below.

TABLE 2 Hole Injection Layer/ Hole Transport Layer Light-Emitting Layer Electron Transport Layer/ Electron Injection Layer

Claims

1. A plurality of host materials comprising at least one first host compound and at least second host compound, wherein the first host compound is represented by the following formula 1, and the second host compound is represented by the following formula 2:

wherein

B1 to B7, each independently, are not present, or represent a substituted or unsubstituted (C5-C20) ring, in which carbon atoms of the ring may be replaced with at least one heteroatom selected from nitrogen, oxygen, and sulfur, with the proviso that at least five of B1 to B7 are present, and adjacent rings of B1 to B7 are fused with each other;

Y represents —N(L1-(Ar1)n)—, —O—, —S—, or —C(R1)(R2)—;

L1 represents a single bond, a substituted or unsubstituted (C1-C30)alkylene, a substituted or unsubstituted (C6-C30)arylene, a substituted or unsubstituted (3- to 30-membered)heteroarylene, or a substituted or unsubstituted (C3-C30)cycloalkylene;

Ar1 represents a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, or —N(R3)(R4);

R1 to R4, 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 ring(s); and

n represents an integer of 1 or 2, where if n is 2, each of Ar1 may be the same or different;

wherein

X represents —N═, —NR35—, —O— or —S—;

Z represents —N═, —NR36—, —O— or —S—, where if X represents —N═, Z represents —NR36—, —O— or —S—, and if X represents —NR35—, Z represents —N═, —O— or —S—;

HAr represents a substituted or unsubstituted (3- to 30-membered)heteroaryl;

R31 represents a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 30-membered)heteroaryl;

R32 to R34, 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, 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, or -L3-N(Ar2)(Ar3); or may be linked to an adjacent substituent to form a ring(s);

R35 and R36, 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, 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, or -L3-N(Ar2)(Ar3);

L2 and L3, each independently, represent a single bond, a substituted or unsubstituted (C6-C30)arylene, or a substituted or unsubstituted (3- to 30-membered)heteroarylene;

Ar2 and Ar3, each independently, represent hydrogen, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C2-C30)alkenyl, a substituted or unsubstituted fused ring group of a (C3-C30) aliphatic ring(s) and a (C6-C30) aromatic ring(s), a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 30-membered)heteroaryl; and

a′ represents 1, b′ and c′, each independently, represent an integer of 1 or 2, and d′ represents an integer of 1 to 4, where if each of b′, c′ and d′ is an integer of 2 or more, each of R32 to each of R34 may be the same or different.

2. The plurality of host materials according to claim 1, wherein the substituents of the substituted alkyl, the substituted alkylene, the substituted alkenyl, the substituted aryl, the substituted arylene, the substituted heteroaryl, the substituted heteroarylene, the substituted cycloalkyl, the substituted cycloalkylene, the substituted alkoxy, the substituted trialkylsilyl, the substituted dialkylarylsilyl, the substituted alkyldiarylsilyl, the substituted triarylsilyl, the substituted fused ring of an aliphatic ring(s) and an aromatic ring(s), and the substituted ring, 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 (3- to 50-membered)heteroaryl unsubstituted or substituted with at least one of a (C1-C30)alkyl(s), a (C6-C30)aryl(s), and a di(C6-C30)arylamino(s); a (C6-C30)aryl unsubstituted or substituted with at least one of deuterium, a cyano(s), a (C1-C30)alkyl(s), a (3- to 50-membered)heteroaryl(s), a mono- or di-(C6-C30)arylamino(s), and a tri(C6-C30)arylsilyl(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-(C2-C30)alkenylamino; a mono- or di-(C6-C30)arylamino; a mono- or di-(3- to 30-membered)heteroarylamino; a (C1-C30)alkyl(C2-C30)alkenylamino; a (C1-C30)alkyl(C6-C30)arylamino; a (C1-C30)alkyl(3- to 30-membered)heteroarylamino; a (C2-C30)alkenyl(C6-C30)arylamino; a (C2-C30)alkenyl(3- to 30-membered)heteroarylamino; a (C6-C30)aryl(3- to 30-membered)heteroarylamino; 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.

3. The plurality of host materials according to claim 1, wherein formula 1 is represented by at least one of the following formulas 1-1 to 1-4:

wherein

Y1, Y2, Y3, and Y4, each independently, are the same as the definition of Y in claim 1, where if a plurality of Ar1's are present, each of Ar1 may be the same or different;

X1 to X12, each independently, represent —N═ or —C(Ra)═; and

Ra, 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, or a substituted or unsubstituted (C3-C30)cycloalkyl; or adjacent Ra's may be linked to each other to form a ring(s), where if a plurality of Ra's are present, each of Ra may be the same or different.

4. The plurality of host materials according to claim 3, wherein at least one of Ar1(s) and Ra(s), each independently, is at least one selected from those listed in the following group 1:

wherein

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

X21 represents O, S, NR5, or C(R6)(R7);

X22, each independently, represents CR8 or N, with the proviso that at least one of X22 represents N;

X23, each independently, represents CR9 or N;

L11 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;

R11 to R21 and R5 to R9, 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 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, where if each of aa to gg is an integer of 2 or more, each of R11 to each of R17 may be the same or different.

5. The plurality of host materials according to claim 3, wherein at least one of Ar1(s) and Ra(s), each independently, is at least one selected from those listed in the following groups 2 and 3:

in group 2,

L represents a single bond, a substituted or unsubstituted (C1-C30)alkylene, a substituted or unsubstituted (C6-C30)arylene, a substituted or unsubstituted (3- to 30-membered)heteroarylene, or a substituted or unsubstituted (C3-C30)cycloalkylene; and

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

6. The plurality of host materials according to claim 1, wherein in formula 1, B1 to B7, each independently, are not present, or represent a substituted or unsubstituted benzene ring, a substituted or unsubstituted naphthalene ring, a substituted or unsubstituted pyrrole ring, a substituted or unsubstituted furan ring, a substituted or unsubstituted thiophene ring, a substituted or unsubstituted cyclopentadiene ring, a substituted or unsubstituted fluorene ring, a substituted or unsubstituted pyridine ring, or a substituted or unsubstituted dibenzofuran ring, with the proviso that at least five of B1 to B7 are present, and adjacent rings of B1 to B7 are fused with each other.

7. The plurality of host materials according to claim 1, wherein formula 2 is represented by at least one selected from the following formulas 2-1 to 2-8:

wherein

X, Z, HAr, R31 to R38, L2 and a′ to d′ are as defined in claim 1;

Z1 to Z5 and Z11 to Z17, each independently, represent N or CR37; and

R37, each independently, is the same as the definition of R32.

8. The plurality of host materials according to claim 1, wherein in formula 2, HAr represents a substituted or unsubstituted triazinyl, a substituted or unsubstituted pyridyl, a substituted or unsubstituted pyrimidinyl, a substituted or unsubstituted quinazolinyl, a substituted or unsubstituted benzoquinazolinyl, a substituted or unsubstituted quinoxalinyl, a substituted or unsubstituted benzoquinoxalinyl, a substituted or unsubstituted quinolyl, a substituted or unsubstituted benzoquinolyl, a substituted or unsubstituted isoquinolyl, a substituted or unsubstituted benzoisoquinolyl, a substituted or unsubstituted triazolyl, a substituted or unsubstituted pyrazolyl, a substituted or unsubstituted naphthyridinyl, a substituted or unsubstituted triazanaphthyl, or a substituted or unsubstituted benzothienopyrimidinyl.

9. The plurality of host materials according to claim 1, wherein the compound represented by formula 1 is at least one selected from the following compounds:

10. The plurality of host materials according to claim 1, wherein the compound represented by formula 2 is at least one selected from the following compounds:

11. An organic electroluminescent device comprising an anode, a cathode, and at least one light-emitting layer between the anode and the cathode, wherein at least one of the light-emitting layers comprises the plurality of host materials according to claim 1.