JP2017508715A - Organic electroluminescent compound and organic electroluminescent device comprising the same - Google Patents

Abstract

The present invention relates to a novel organic electroluminescent compound and an organic electroluminescent device including the same. By using the organic electroluminescent compound according to the present invention, an organic electroluminescent device having excellent current efficiency and lifetime characteristics can be produced. [Selection figure] None

Description

  The present invention relates to an organic electroluminescent compound and an organic electroluminescent device including the same.

  An electroluminescent device (EL device) is a self-emitting device that has advantages in providing a wider viewing angle, a better contrast ratio, and a faster response time. Organic EL devices were first developed by Eastman Kodak by using aromatic diamine small molecules and aluminum complexes as materials for forming the light-emitting layer [Appl. Phys. Lett. 51, 913, 1987].

The most important factor that determines the luminous efficiency in an organic EL device is a luminescent material. To date, fluorescent materials have been widely used as luminescent materials. However, from the point of view of the electroluminescent mechanism, phosphorescent materials theoretically enhance luminous efficiency four (4) times compared to fluorescent materials, so the development of phosphorescent luminescent materials has been widely studied. ing. Iridium (III) complexes are widely known as phosphorescent materials and are bis (2- (2'-benzothienyl) -pyridinato-N, C3 ') iridium (acetylacetonate) ((acac) Ir (btp ₂ ), tris (2-phenylpyridine) iridium (Ir (ppy) ₃ ), and bis (4,6-difluorophenylpyridinato-N, C2) picolinate iridium (Firpic) are red and green, respectively. , And blue materials.

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

  Although these phosphorescent host materials provide good luminescent properties, they have the following disadvantages: (1) High temperature deposition in vacuum due to their low glass transition temperature and low thermal stability Their degradation can occur during processing and the lifetime of the device is reduced. (2) The power efficiency of the organic EL device is given by [(π / voltage) × current efficiency], and this power efficiency is inversely proportional to the voltage. Organic EL devices that include phosphorescent host materials provide higher current efficiency (cd / A) than those that include fluorescent materials, but require very high drive voltages. Therefore, there is no advantage in terms of power efficiency (lm / W). (3) Furthermore, the operating life of the organic EL device is short, and the light emission efficiency still needs to be improved.

  On the other hand, in order to enhance the efficiency and stability, the organic EL device has a multilayer structure including a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer. Selection of a compound contained in the hole transport layer is known as a method for improving device characteristics such as efficiency of hole transport to the light emitting layer, light emission efficiency, and lifetime.

  In this regard, copper phthalocyanine (CuPc), 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPB), N, N′-diphenyl-N, N′-bis (3 -Methylphenyl)-(1,1′-biphenyl) -4,4′-diamine (TPD), 4,4 ′, 4 ″ -tris (3-methylphenylphenylamino) triphenylamine (MTDATA), etc. It has been used as a hole injection and transport material. However, organic EL devices using these materials have problems in terms of quantum efficiency and operating lifetime. This is because when an organic EL device is driven under a high current, thermal stress is generated between the anode and the hole injection layer. Thermal stress significantly reduces the operating life of the device. Furthermore, since the organic material used in the hole injection layer has a very high hole mobility, the hole-electron charge balance may be lost, and the quantum efficiency (cd / A) may be reduced. .

  Therefore, there remains a need to develop a hole transport layer to improve the durability of organic EL devices.

  Japanese Unexamined Patent Publication No. 2001-196177 discloses a compound in which two benzene rings of fluorene are each substituted with a diarylamine as an organic electroluminescent compound. However, the above references do not disclose organic electroluminescent devices that use compounds in which one benzene ring of fluorene is substituted with two diarylamines.

  The goal of the present invention is to provide an organic electroluminescent compound having excellent luminous efficiency and lifetime characteristics.

  The inventors have discovered that the above goals can be achieved by an organic electroluminescent compound represented by the following formula 1:

Where
L ₁ and L ₂ each independently represent a single bond, a substituted or unsubstituted (C 6 -C 30) arylene, or a substituted or unsubstituted (3 to 30 membered) heteroarylene,
Ar _{1 to} Ar ₄ are each independently substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (3 to 7 membered) heterocycloalkyl, substituted Or represents unsubstituted (C6-C30) aryl, or substituted or unsubstituted (3-30 membered) heteroaryl,
R ₁ and R ₂ are each independently substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (3-7 membered) heterocycloalkyl, substituted Or an unsubstituted (C6-C30) aryl, or a substituted or unsubstituted (3-30 membered) heteroaryl, or linked together, monocyclic or polycyclic (C3-C30) alicyclic or aromatic Forming a family ring,
R ₃ is hydrogen, deuterium, halogen, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (3 to 30 membered) heteroaryl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (3-7 membered) heterocycloalkyl, substituted or unsubstituted (C6-C30) aryl (C1-C30) _{alkyl, -NR 4 R 5, -SiR 6} R 7 Represents R ₈ , cyano, nitro, or hydroxyl, or is linked to adjacent substituent (s) to form a monocyclic or polycyclic (C3-C30) alicyclic or aromatic ring;
R ₄ and R ₅ are each independently hydrogen, deuterium, halogen, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl, or substituted or unsubstituted (3-30 Member) represents heteroaryl,
R _{6 to} R ₈ are each independently hydrogen, deuterium, halogen, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (3 to 30 members) ) Represents a heteroaryl, substituted or unsubstituted (3-7 membered) heterocycloalkyl, or substituted or unsubstituted (C3-C30) cycloalkyl, or linked to adjacent substituent (s) monocyclic Or a polycyclic (C3-C30) alicyclic or aromatic ring, the carbon atom (s) of which may be replaced with at least one heteroatom selected from nitrogen, oxygen, and sulfur ,
a represents an integer of 1 to 4, and when a is an integer of 2 or more, each of R ₃ may be the same or different;
Heteroaryl (ene) and heterocycloalkyl each independently contain at least one heteroatom selected from B, N, O, S, P (═O), Si, and P.

  By using the organic electroluminescent compound according to the present invention, an organic electroluminescent device having excellent current efficiency and luminous efficiency can be produced.

  The present invention will now be described in detail. However, the following description is intended to illustrate the present invention and is not meant to limit the scope of the invention in any way.

  The present invention relates to an organic electroluminescent compound of formula 1, an organic electroluminescent material comprising this compound, and an organic electroluminescent device comprising this material.

  The organic electroluminescent compound represented by the above formula 1 will be described in detail.

  In the present specification, “(C1-C30) alkyl” means a linear or branched alkyl having 1 to 30 carbon atoms, in which the number of carbon atoms is preferably 1 to 10, more Preferably it is 1-6, including methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, etc .; “(C2-C30) alkenyl” is 2-30 carbon atoms In which the number of carbon atoms is preferably 2-20, more preferably 2-10, vinyl, 1-propenyl, 2-propenyl, 1-butenyl , 2-butenyl, 3-butenyl, 2-methylbut-2-enyl, etc .; “(C2-C30) alkynyl” is a straight or branched chain alkenyl having 2 to 30 carbon atoms. Nyl means, in which the number of carbon atoms is preferably 2 to 20, more preferably 2 to 10, and ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3- Butynyl, 1-methylpent-2-ynyl and the like; “(C3-C30) cycloalkyl” is a monocyclic or polycyclic hydrocarbon having from 3 to 30 carbon atoms, in which carbon The number of atoms is preferably 3-20, more preferably 3-7, and includes cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc .; “(3-7 membered) heterocycloalkyl” means B, N Cycloalkyl having 3 to 7 ring skeleton atoms, including at least one heteroatom selected from O, S, P (= O), Si, and P, preferably O, S, and N And includes tetrahydrofuran, pyrrolidine, thiolane, tetrahydropyran, etc .; “(C6-C30) aryl (ene)” is a monocyclic ring having 6-30 carbon atoms and derived from an aromatic hydrocarbon Or a condensed ring, in which the number of carbon atoms is preferably 6-20, more preferably 6-15, phenyl, biphenyl, terphenyl, naphthyl, binaphthyl, phenylnaphthyl, naphthylphenyl, fluorenyl, Phenylfluorenyl, benzofluorenyl, dibenzofluorenyl, phenanthrenyl, phenylphenanthrenyl, anthracenyl, indenyl, triphenylenyl, pyrenyl, tetracenyl, perylenyl, chrycenyl, naphthacenyl, fluoranthenyl, etc .; ˜30 membered heteroaryl ( En) "includes at least 1, preferably 1 to 4 heteroatoms selected from the group consisting of B, N, O, S, P (= O), Si, and P. Having a ring skeleton atom, a monocyclic ring or a condensed ring fused with at least one benzene ring, which may be partially saturated, and at least one heteroaryl or aryl group may be bonded to a single bond (s). ) By way of linking to a heteroaryl group, furyl, thiophenyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, triazinyl, tetrazinyl, triazolyl, tetrazolyl, furazanyl, Pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl As well as benzofuranyl, benzothiophenyl, isobenzofuranyl, dibenzofuranyl, dibenzothiophenyl, benzonaphththiophenyl, benzimidazolyl, benzothiazolyl, benzoisothiazolyl, benzoisoxazolyl, Examples include fused-ring heteroaryls including benzoxazolyl, isoindolyl, indolyl, indazolyl, benzothiadiazolyl, quinolyl, isoquinolyl, cinolinyl, quinazolinyl, quinoxalinyl, carbazolyl, phenoxazinyl, phenanthridinyl, benzodioxolyl, etc. . Furthermore, “halogen” includes F, Cl, Br, and I.

  According to certain embodiments of the invention, the compound of formula 1 can be represented by the following formula 2:

In the formula, L ₁ , L ₂ , Ar _{1 to} Ar ₄ , R _{1 to} R ₃ , and a are as defined in Formula 1.

In the present specification, the term “substituted” in the expression “substituted or unsubstituted” means that a hydrogen atom in a specific functional group is replaced with another atom or group, that is, a substituent. _L 1 of Formula _{1, L 2, Ar 1 ~Ar} 4, and substituted (C1-C30) in _R 1 to R ₈ alkyl, substituted (C3-C30) cycloalkyl, substituted (3-7 membered) heterocycloalkyl , Substituted (C6-C30) aryl (ene), substituted (3-30 membered) heteroaryl (ene), and substituted (C6-C30) aryl (C1-C30) alkyl substituents are each independently Hydrogen, halogen, cyano, carboxyl, nitro, hydroxyl, (C1-C30) alkyl, halo (C1-C30) alkyl, (C2-C30) alkenyl, (C2-C30) alkynyl, (C1-C30) alkoxy, (C1 -C30) alkylthio, (C3-C30) cycloalkyl, (C3-C30) cycloalkenyl, (3-7 membered) heterocycloalkyl, (C -C30) aryloxy, (C6-C30) arylthio, unsubstituted or (3-30 membered) heteroaryl substituted with (C6-C30) aryl, unsubstituted or substituted with (3-30 membered) heteroaryl (C6-C30) aryl, tri (C1-C30) alkylsilyl, tri (C6-C30) arylsilyl, di (C1-C30) alkyl (C6-C30) arylsilyl, (C1-C30) alkyldi (C6-C30 ) Arylsilyl, amino, mono or di (C1-C30) alkylamino, mono or di (C6-C30) arylamino, (C1-C30) alkyl (C6-C30) arylamino, (C1-C30) alkylcarbonyl, (C1-C30) alkoxycarbonyl, (C6-C30) arylcarbonyl Di (C6-C30) aryl boronyl, di (C1-C30) alkyl boronyl, (C1-C30) alkyl (C6-C30) aryl boronyl, (C6-C30) aryl (C1-C30) alkyl, And (C1-C30) alkyl (C6-C30) aryl, preferably each independently (C1-C6) alkyl, (C6-C25) aryl, and ( 5 to 20 member) at least one selected from the group consisting of heteroaryl.

In Formula 1 above, L ₁ and L ₂ each independently represent a single bond, a substituted or unsubstituted (C 6 -C 30) arylene, or a substituted or unsubstituted (3 to 30 membered) heteroarylene, preferably Each independently represents a single bond, substituted or unsubstituted (C6-C12) arylene, or substituted or unsubstituted (5-20 membered) heteroarylene, more preferably each independently a single bond, unsubstituted (C6-C12) arylene or unsubstituted (5-20 membered) heteroarylene.

Ar _{1 to} Ar ₄ are each independently substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (3 to 7 membered) heterocycloalkyl, substituted Or substituted (C6-C30) aryl, or substituted or unsubstituted (3 to 30 membered) heteroaryl, preferably each independently represents substituted or unsubstituted (C6-C15) aryl, more preferably Each independently represents (C6-C15) aryl unsubstituted or substituted with (C1-C6) alkyl, (C6-C15) aryl, or (5-20 membered) heteroaryl.

R ₁ and R ₂ are each independently substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (3-7 membered) heterocycloalkyl, substituted Or an unsubstituted (C6-C30) aryl, or a substituted or unsubstituted (3-30 membered) heteroaryl, or linked together, monocyclic or polycyclic (C3-C30) alicyclic or aromatic Forming a ring, and preferably each independently substituted or unsubstituted (C1-C6) alkyl, substituted or unsubstituted (C6-C20) aryl, or substituted or unsubstituted (5-20 membered) heteroaryl Or linked together to form a monocyclic or polycyclic (C6-C20) alicyclic or aromatic ring, more preferably, Standing, unsubstituted (C1-C6) alkyl; unsubstituted or (C6-C20) aryl substituted with (C1-C6) alkyl, (C6-C25) aryl, or (5-20 membered) heteroaryl; Alternatively, it represents a (5-20 membered) heteroaryl that is unsubstituted or substituted with (C6-C12) aryl, or is linked together to form a monocyclic or polycyclic (C6-C20) aromatic ring. .

R ₃ is hydrogen, deuterium, halogen, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (3 to 30 membered) heteroaryl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (3-7 membered) heterocycloalkyl, substituted or unsubstituted (C6-C30) aryl (C1-C30) _{alkyl, -NR 4 R 5, -SiR 6} R 7 Represents R ₈ , cyano, nitro, or hydroxyl, or is linked to adjacent substituent (s) to form a monocyclic or polycyclic (C3-C30) alicyclic or aromatic ring; Preferably, each independently, hydrogen, substituted or unsubstituted (C6-C12) aryl, substituted or unsubstituted (C5-C12) cycloalkyl, -N ₄ or represents R ₅ or -SiR ₆ R ₇ R _8,, or linked to an adjacent substituent (s) mono- or polycyclic a (C6-C12) cycloaliphatic or aromatic ring More preferably each independently represents hydrogen, unsubstituted (C6-C12) aryl, unsubstituted (C5-C12) cycloalkyl, —NR ₄ R ₅ , or —SiR ₆ R ₇ R ₈ Or linked to adjacent substituent (s) to form a monocyclic (C6-C12) aromatic ring.

R ₄ and R ₅ are each independently hydrogen, deuterium, halogen, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl, or substituted or unsubstituted (3-30 Member) heteroaryl, preferably each independently represents substituted or unsubstituted (C6-C12) aryl, and more preferably each independently represents unsubstituted (C6-C12) aryl.

R _{6 to} R ₈ are each independently hydrogen, deuterium, halogen, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (3 to 30 members) ) Represents a heteroaryl, substituted or unsubstituted (3-7 membered) heterocycloalkyl, or substituted or unsubstituted (C3-C30) cycloalkyl, or linked to adjacent substituent (s) monocyclic Or a polycyclic (C3-C30) alicyclic or aromatic ring, the carbon atom (s) of which may be replaced with at least one heteroatom selected from nitrogen, oxygen, and sulfur Each preferably independently represents a substituted or unsubstituted (C1-C6) alkyl, more preferably each independently an unsubstituted (C1-C6) alkyl. Represent.

a represents an integer of 1 to 4, preferably an integer of 1 to 2, and when a is an integer of 2 or more, each of R ₃ may be the same or different.

  Heteroaryl (ene) and heterocycloalkyl each independently contain at least one heteroatom selected from B, N, O, S, P (═O), Si, and P.

According to one embodiment of the present invention, in Formula 1 above, L ₁ and L ₂ are each independently a single bond, substituted or unsubstituted (C 6 -C 12) arylene, or substituted or unsubstituted (5- 20-membered) represents a heteroarylene, Ar _{1 to} Ar ₄ each independently represents a substituted or unsubstituted (C 6 -C 15) aryl, and R ₁ and R ₂ each independently represent a substituted or unsubstituted ( C1-C6) represents alkyl, substituted or unsubstituted (C6-C20) aryl, or substituted or unsubstituted (5-20 membered) heteroaryl, or linked together to form a monocyclic or polycyclic (C6-C6) C20) to form an alicyclic or aromatic ring, _{R 3} is hydrogen, substituted or unsubstituted (C6-C12) aryl, substituted or unsubstituted (C5-C12) cycloalkyl -NR ₄ R ₅ or -SiR ₆ R ₇ represent a R _8, or monocyclic linked to the adjacent substituent (s) or polycyclic (C6-C12) cycloaliphatic or aromatic, A ring is formed, R ₄ and R ₅ each independently represents a substituted or unsubstituted (C 6 -C 12) aryl, and R _{6 to} R ₈ each independently represents a substituted or unsubstituted (C 1 -C 6). A) represents an integer of 1 to 2;

According to another embodiment of the present invention, in Formula 1 above, L ₁ and L ₂ are each independently a single bond, unsubstituted (C 6 -C 12) arylene, or unsubstituted (5 to 20 members). Represents a heteroarylene, Ar ₁ -Ar ₄ are each independently unsubstituted or substituted with (C1-C6) alkyl, (C6-C15) aryl, or (5-20 membered) heteroaryl (C6- C15) represents aryl, and R ₁ and R ₂ are each independently unsubstituted (C1-C6) alkyl, unsubstituted or (C1-C6) alkyl, (C6-C25) aryl, or (5-20 members) ) Represents (C6-C20) aryl substituted with heteroaryl, or (5-20 membered) heteroaryl unsubstituted or substituted with (C6-C12) aryl, or Connected to form a monocyclic or polycyclic (C6-C20) aromatic ring, R ₃ is hydrogen, unsubstituted (C6-C12) aryl, unsubstituted (C5-C12) cycloalkyl, —NR ₄ R ₅ , or —SiR ₆ R ₇ R ₈ , or linked to adjacent substituent (s) to form a monocyclic (C 6 -C 12) aromatic ring, R ₄ and R ₅ are Each independently represents unsubstituted (C6-C12) aryl, R _{6 to} R ₈ each independently represents unsubstituted (C1-C6) alkyl, and a represents an integer of 1 to 2.

  Specific compounds of the present invention include, but are not limited to, the following compounds:

  The organic electroluminescent compounds of the present invention can be prepared by synthetic methods known to those skilled in the art. For example, they can be prepared according to the following reaction scheme.

In the formula, L ₁ , L ₂ , Ar _{1 to} Ar ₄ , R _{1 to} R ₃ , and a are as defined in Formula 1 above.

  The present invention provides an organic electroluminescent material comprising an organic electroluminescent compound of Formula 1 and an organic electroluminescent device comprising the material.

  The materials described above can be composed of the organic electroluminescent compound according to the present invention alone, or can further include conventional materials commonly used in organic electroluminescent materials.

  The organic electroluminescent device comprises a first electrode, a second electrode, and at least one organic layer between the first electrode and the second electrode. The organic layer can include at least one organic electroluminescent compound of Formula 1.

  One of the first and second electrodes can be an anode and the other can be a cathode. The organic layer includes a light emitting layer, and at least one selected from the group consisting of a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, an intermediate layer, a hole blocking layer, and an electron blocking layer. A layer may further be included.

  The organic electroluminescent compound according to the present invention may be included in at least one of the light emitting layer and the hole transport layer. When used in a hole transport layer, the organic electroluminescent compound of the present invention may be included as a hole transport material. When used in a light emitting layer, the organic electroluminescent compound of the present invention can be included as a host material.

  An organic electroluminescent device comprising the organic electroluminescent compound of the present invention may further comprise one or more compounds other than the organic electroluminescent compound according to the present invention, and may further comprise one or more dopants.

  When the organic electroluminescent compound according to the present invention is included as a host material (first host material), other compounds may be included as the second host material. Here, the weight ratio of the first host material and the second host material is in the range of 1:99 to 99: 1.

Host materials other than organic electroluminescent compounds according to the present invention can be derived from any of the known phosphorescent host materials. Specifically, a phosphorescent host selected from the group consisting of the compounds of the following formulas 11 to 13 is preferable from the viewpoint of luminous efficiency.
_{H- (Cz-L 4) h} -M ---------- (11)
_{H- (Cz) i -L 4 -M} ---------- (12)

  In the formula, Cz represents the following structure:

R _{21 to} R ₂₄ are each independently hydrogen, deuterium, halogen, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (3 to 30 members) ) Represents heteroaryl, or -SiR ₂₅ R ₂₆ R ₂₇
R _{25 to} R ₂₇ each independently represent a substituted or unsubstituted (C1-C30) alkyl, or a substituted or unsubstituted (C6-C30) aryl,
L ₄ represents a single bond, a substituted or unsubstituted (C6-C30) arylene, or a substituted or unsubstituted (5-30 membered) heteroarylene,
M represents substituted or unsubstituted (C6-C30) aryl, or substituted or unsubstituted (5-30 membered) heteroaryl,
Y ₁ and Y ₂ each independently represent —O—, —S—, —N (R ₃₁ ) —, or —C (R ₃₂ ) (R ₃₃ ) —, provided that Y ₁ and Y ₂ is not present at the same time,
R _{31 to} R ₃₃ each independently represents substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl, or substituted or unsubstituted (5 to 30 membered) heteroaryl, R ₃₂ and R ₃₃ may be the same or different;
h and i each independently represent an integer of 1 to 3,
j, k, b, and c each independently represent an integer of 0 to 4;
When h, i, j, k, b, or c is an integer of 2 or more, each of (Cz−L ₄ ), each of (Cz), each of R ₂₁ , each of R ₂₂ , and each of R ₂₃ Or each of R ₂₄ may be the same or different.

  Specifically, preferred examples of host materials are as follows:

  [Wherein TPS represents triphenylsilyl]

  The dopant contained in the organic electroluminescent device according to the present invention is preferably at least one phosphorescent dopant. The dopant material applied to the organic electroluminescent device according to the present invention is not limited, but may preferably be selected from iridium, osmium, copper and platinum metallized complex compounds, more preferably iridium, It can be selected from osmium, copper, and platinum orthometalated complex compounds, and even more preferably an orthometalated iridium complex compound.

  The phosphorescent dopant may preferably be selected from compounds represented by the following formulas 101-103.

  Where L is selected from the following structures:

R ₁₀₀ represents hydrogen, substituted or unsubstituted (C1-C30) alkyl, or substituted or unsubstituted (C3-C30) cycloalkyl,
R ₁₀₁ to R ₁₀₉ and _R 111 _{to R 123} are each independently hydrogen, deuterium, halogen, unsubstituted or halogen substituted with (s) (C1-C30) alkyl, cyano, substituted or unsubstituted Represents (C1-C30) alkoxy, substituted or unsubstituted (C6-C30) aryl, or substituted or unsubstituted (C3-C30) cycloalkyl, R _{106 to} R ₁₀₉ linked to adjacent substituent (s) To form a substituted or unsubstituted fused ring, such as unsubstituted or alkyl substituted fluorene, unsubstituted or alkyl substituted dibenzothiophene, or unsubstituted or alkyl substituted dibenzofuran, R _{120 to} R ₁₂₃ is a substituted or unsubstituted fused ring linked to an adjacent substituent (s), for example, Substituted or halogen, alkyl or can form substituted quinoline aryl,
R _{124 to} R ₁₂₇ each independently represents hydrogen, deuterium, halogen, substituted or unsubstituted (C 1 -C 30) alkyl, or substituted or unsubstituted (C 6 -C 30) aryl, and R _{124 to} R ₁₂₇ are Substituted or unsubstituted fused rings linked to adjacent substituent (s), eg, unsubstituted or alkyl substituted fluorene, unsubstituted or alkyl substituted dibenzothiophene, or unsubstituted or substituted with alkyl Can form dibenzofuran,
R _{201 to} R ₂₁₁ are each independently hydrogen, deuterium, halogen, unsubstituted or substituted (C1-C30) alkyl with halogen (s), substituted or unsubstituted (C3-C30) cycloalkyl, Or substituted or unsubstituted (C6-C30) aryl, wherein R _{208 to} R ₂₁₁ are fluorenes linked to adjacent substituent (s) and substituted or unsubstituted condensed rings such as unsubstituted or alkyl substituted Can form an unsubstituted or alkyl-substituted dibenzothiophene, or an unsubstituted or alkyl-substituted dibenzofuran;
f and g each independently represent an integer of 1 to 3, and when f or g is an integer of 2 or more, each of R ₁₀₀ may be the same or different;
n represents an integer of 1 to 3.

  Specifically, phosphorescent dopant materials include the following:

  In another embodiment of the present invention, a composition for preparing an organic electroluminescent device is provided. This composition comprises a compound according to the invention as a host material or a hole transport material.

  In addition, the organic electroluminescent device according to the present invention comprises a first electrode, a second electrode, and at least one organic layer between the first electrode and the second electrode. The organic layer comprises a light emitting layer, which may comprise a composition for preparing an organic electroluminescent device according to the present invention.

  In addition to the organic electroluminescent compound represented by Formula 1, the organic electroluminescent device according to the present invention may further include at least one compound selected from the group consisting of arylamine-based compounds and styrylarylamine-based compounds.

  In the organic electroluminescent device according to the present invention, the organic layer is composed of a metal of Group 1 of the periodic table, a metal of Group 2, a transition metal of the fourth period, a transition metal of the fifth period, a lanthanide, and a d-orbital transition element. It may further comprise at least one metal selected from the group consisting of organic metals, or at least one complex compound containing the metal. The organic layer may further include a light emitting layer and a charge generation layer.

  In addition, the organic electroluminescent device according to the present invention comprises, in addition to the compound according to the present invention, at least one light emitting layer comprising a blue electroluminescent compound, a red electroluminescent compound, or a green electroluminescent compound known in the art. Further inclusions can emit white light. A yellow or orange light emitting layer can also be included in the device if desired.

According to the present invention, at least one layer selected from a chalcogenide layer, a metal halide layer, and a metal oxide layer (hereinafter “surface layer”) is preferably one or both of the electrode (s). Installed on internal surface (s). Specifically, a chalcogenide (including oxide) layer of silicon or aluminum is preferably placed on the anode surface of the electroluminescent medium layer, and the metal halide layer and metal oxide layer are preferably electroluminescent medium. Placed on the cathode surface of the layer. Such a surface layer provides operational stability for the present organic electroluminescent device. Preferably, the chalcogenide includes SiO _X (1 ≦ X ≦ 2), AlO _X (1 ≦ X ≦ 1.5), SiON, SiAlON, etc., and the metal halide includes LiF, MgF ₂ , CaF ₂ , The rare earth metal fluoride is included, and the metal oxide includes Cs ₂ O, Li ₂ O, MgO, SrO, BaO, CaO and the like.

  In the organic electroluminescent device according to the present invention, the mixed region of the electron transport compound and the reducing dopant or the mixed region of the hole transport compound and the oxidizing dopant is preferably on at least one surface of the pair of electrodes. Installed. In this case, the electron transport compound is reduced to an anion, thus making it easier to inject and transport electrons from the mixed region to the electroluminescent medium. Further, the hole transport compound is oxidized to a cation, thus making it easier to inject and transport holes from the mixed region to the electroluminescent medium. Preferably, the oxidizing dopant includes various Lewis acids and acceptor compounds, and the reducing dopant includes alkali metals, alkali metal compounds, alkaline earth metals, rare earth metals, and mixtures thereof. The reducing dopant layer can be used as a charge generation layer to prepare an electroluminescent device that has two or more electroluminescent layers and emits white light.

  In order to form each layer of the organic electroluminescent device according to the present invention, a dry film forming method such as vacuum deposition, sputtering, plasma and ion plating method, or a wet film forming method such as spin coating, dip coating, and flow coating method. Can be used.

  When the wet film-forming method is used, a thin layer can be formed by dissolving or diffusing the material forming each layer in any suitable solvent such as ethanol, chloroform, tetrahydrofuran, dioxane and the like. The solvent can be any solvent that can dissolve or diffuse the material forming each layer and has no problem with the film forming ability.

  The organic electroluminescent compound, the method for preparing the compound, and the luminescent properties of the device will now be described in detail with reference to the following examples.

  Example 1: Preparation of compound C-1

Preparation of Compound 1-2 2,4-Dichlorophenylboronic acid (Compound 1-1) (64 g, 335 mmol), Methyl 2-bromobenzoate (60 g, 279 mmol), Tetrakis (triphenylphosphine) palladium (9.5 g, 8 0.4 mmol), potassium carbonate (96 g, 698 mmol), 600 mL of toluene, and 300 mL of ethanol were introduced into the reaction vessel, 300 mL of distilled water was added to the mixture, and the mixture was stirred at 120 ° C. for 3 hours. After the reaction, the mixture was washed with distilled water, and the organic layer was extracted with ethyl acetate. The extracted organic layer was dried over magnesium sulfate and the solvent was removed using a rotary evaporator. The remaining material was then purified by column chromatography to give compound 1-2 (79 g, 99%).

Preparation of Compound 1-3 After introducing Compound 1-2 (79 g, 279 mmol), 110 mL Eaton's reagent, and 1 L chlorobenzene into the reaction vessel, the mixture was stirred overnight while refluxing. After the reaction solution was cooled to room temperature, the reaction was completed with water, and the organic layer was extracted with methylene chloride. The extracted organic layer was dried over magnesium sulfate and the solvent was removed using a rotary evaporator. The remaining material was then purified by column chromatography to give compound 1-3 (49 g, 71%).

Preparation of Compound 1-4 Iodine (18 g, 71 mmol), hypophosphorous acid (35 mL, 315 mmol, 50% aqueous solution), and 1 L of acetic acid were introduced into the reaction vessel, and then the mixture was stirred at 100 ° C. for 30 minutes. Thereafter, Compound 1-3 was slowly added dropwise to the reaction vessel, and the mixture was stirred overnight while refluxing. After the reaction solution was cooled to room temperature, the precipitated solid was filtered and washed with a large amount of hexane. The filtrate was diluted with ethyl acetate and washed with water. The extracted organic layer was dried over magnesium sulfate and the solvent was removed using a rotary evaporator. The remaining material was then purified by column chromatography to give compound 1-4 (35.7 g, 77%).

Preparation of Compound 1-5 Compound 1-4 (35.5 g, 151 mmol), potassium hydroxide (42 g, 760 mmol), potassium iodide (2.5 g, 15 mmol), benzyltriethylammonium chloride (1.7 g, 7.8 mmol) ), 700 mL of distilled water and 700 mL of dimethyl sulfoxide were introduced into the reaction vessel, and the mixture was stirred at room temperature for 15 minutes. Then methyl iodide (25 mL, 378 mmol) was added thereto and the mixture was stirred overnight at room temperature. The reaction solution was diluted with ethyl acetate and washed with distilled water. The extracted organic layer was dried over magnesium sulfate and the solvent was removed using a rotary evaporator. The remaining material was then purified by column chromatography to give compound 1-5 (32 g, 81%).

Preparation of Compound C-1 Compound 1-5 (7 g, 26.6 mmol), dibiphenyl-4-ylamine (17 g, 52.9 mmol), tris (dibenzylideneacetone) dipalladium (0) (1.9 g, 2. 1 mmol), s-phos (1.1 g, 2.7 mmol), sodium t-butoxide (6.4 g, 67 mmol), and 150 mL of o-xylene were introduced into the reaction vessel, and the mixture was stirred for 1 hour while refluxing . Thereafter, the reaction solution cooled to room temperature was diluted with ethyl acetate and washed several times with water. The extracted organic layer was then dried over anhydrous magnesium sulfate, distilled under reduced pressure, and purified by column chromatography to obtain compound C-1 (9.6 g, 55%).

  Example 2: Preparation of compound C-9

Preparation of Compound 2-1 After introducing Compound 3-1 (20.5 g, 82.3 mol) and 400 mL of tetrahydrofuran into a reaction vessel, the reaction solution was cooled to 0 ° C., and phenylmagnesium bromide (40 mL, 123 mmol) and A 3M diethyl ether solution was slowly added dropwise. The reaction solution was stirred at room temperature for 1 hour. Thereafter, the reaction was completed with an aqueous ammonium chloride solution, and the reaction solution was diluted with ethyl acetate and washed with water. The extracted organic layer was then dried over anhydrous magnesium sulfate, distilled under reduced pressure, and purified by column chromatography to give compound 2-1 (28 g, 99%).

Preparation of Compound 2-2 Compound 2-1 (15.8 g, 48.3 mmol), 9-phenylcarbazole (17.6 g, 72.5 mmol), and 250 mL of methylene chloride (MC) were introduced into a reaction vessel, and then the mixture was mixed. Was subjected to a nitrogen atmosphere. Then, 1.5 mL Eaton's reagent was slowly added dropwise to the reaction vessel and the mixture was stirred at room temperature for 2 hours. The reaction was then completed with distilled water and the mixture was extracted with methylene chloride. The extracted organic layer was dried over magnesium sulfate and the solvent was removed using a rotary evaporator. The remaining material was then purified by column chromatography to give compound 2-2 (13.2 g, 49%).

Preparation of Compound C-9 Compound 2-2 (13 g, 26.6 mmol), dibiphenylamine (8 g, 47 mmol), tris (dibenzylideneacetone) dipalladium (0) (1.7 g, 1.9 mmol), s- Phos (0.96 g, 2.35 mmol), sodium t-butoxide (5.6 g, 58.8 mmol), and 120 mL of o-xylene were introduced into the reaction vessel, and the mixture was stirred at reflux overnight. Thereafter, the reaction solution cooled to room temperature was diluted with ethyl acetate and washed several times with water. The extracted organic layer was then dried over anhydrous magnesium sulfate, distilled under reduced pressure, and purified by column chromatography to give compound C-9 (10 g, 52%).

Device Example 1: Manufacture of OLED devices using organic electroluminescent compounds according to the present invention OLED devices were manufactured using organic electroluminescent compounds according to the present invention. A transparent electrode indium tin oxide (ITO) thin film (10Ω / sq) (Geomatec, Japan) on a glass substrate for an organic light emitting diode (OLED) device was subjected to ultrasonic cleaning with acetone and isopropanol and then in isopropanol. Stored. Next, the ITO substrate was placed on the substrate holder of the vacuum evaporation apparatus. N ^{4, N 4 '-} biphenyl ^-N 4, ^{N 4'} - bis (9-phenyl -9H- carbazol-3-yl) - a [1,1'-biphenyl] -4,4'-diamine, vacuum It was introduced into the cell of the vapor deposition apparatus and then the pressure in the chamber of the apparatus was controlled to 10 ⁻⁶ Torr. Thereafter, a current was applied to the cell to evaporate the introduced material, thereby forming a first hole injection layer having a thickness of 80 nm on the ITO substrate. 1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile (HAT-CN) is then introduced into another cell of the vacuum deposition apparatus and evaporated by applying a current to the cell, Thus, a second hole injection layer having a thickness of 5 nm was formed on the first hole injection layer. The lower compound T-1 is then introduced into another cell of the vacuum deposition apparatus and evaporated by applying a current to the cell, thereby having a thickness of 10 nm on the second hole injection layer. A first hole transport layer was formed. Compound C-1 is then introduced into another cell of the vacuum deposition apparatus and evaporated by applying a current to the cell, whereby a second having a thickness of 60 nm on the first hole transport layer. The hole transport layer was formed. Then, compound H-1 was introduced into one cell of the vacuum evaporation apparatus as a host, and compound D-96 was introduced into another cell as a dopant. The two materials were evaporated at different rates and deposited with a doping amount of 3% by weight based on the total amount of host and dopant to form a light emitting layer having a thickness of 40 nm on the second hole transport layer. Then, 2- (4- (9,10-di (naphthalen-2-yl) anthracen-2-yl) phenyl) -1-phenyl-1H-benzo [d] imidazole was introduced into one cell, and quinolinic acid Lithium was introduced into another cell. The two materials were evaporated at the same rate and each was deposited with a doping amount of 50% by weight to form an electron transport layer having a thickness of 35 nm on the light emitting layer. Next, lithium quinolinate was deposited on the electron transport layer as an electron injection layer having a thickness of 2 nm, and then an Al cathode having a thickness of 80 nm was deposited on the electron injection layer by another vacuum deposition apparatus. It was. Thus, an OLED device was manufactured. All materials used to make OLED devices were purified by vacuum sublimation at ^10-6 torr before use.

The manufactured OLED device showed red emission, had a luminance of 800 cd / m ² and a current density of 2.8 mA / cm ² . Regarding the lifetime characteristics, the time until the luminance decreased to 90% at 5,000 nits was 800 hours.

Device Example 2: Preparation of an OLED device using an organic electroluminescent compound according to the invention Device Example 1 with the exception that Compound C-9 was evaporated to form a second hole transport layer with a thickness of 60 nm. OLED devices were manufactured in the same manner.

The manufactured OLED device showed red emission and had a luminance of 1500 cd / m ² and a current density of 5.2 mA / cm ² . Regarding the lifetime characteristics, the time until the luminance decreased to 90% at 5,000 nits was 750 hours.

Device Example 3: Preparation of an OLED device using an organic electroluminescent compound according to the invention Device Example 1 with the exception that Compound C-67 was evaporated to form a second hole transport layer having a thickness of 60 nm. OLED devices were manufactured in the same manner.

The manufactured OLED device showed red emission and had a luminance of 1200 cd / m ² and a current density of 4.2 mA / cm ² . Regarding the lifetime characteristics, the time until the luminance decreased to 90% at 5,000 nits was 780 hours.

Comparative Example 1 Production of OLED Device Containing Conventional Organic Electroluminescent Compound In the same manner as Device Example 1 except that the second compound was evaporated to form a second hole transport layer with a thickness of 60 nm. An OLED device was manufactured.

The manufactured OLED device showed red emission, had a luminance of 2000 cd / m ² and a current density of 11.2 mA / cm ² . Regarding the lifetime characteristics, the time until the luminance decreased to 90% at 5,000 nits was 67 hours.

  The luminescent properties of the organic electroluminescent compounds according to the present invention are demonstrated to be superior to conventional materials. In addition, the organic electroluminescent device using the organic electroluminescent compound according to the present invention has excellent light emission characteristics and lifetime characteristics.

Claims (7)

An organic electroluminescent compound represented by Formula 1 below:

Where
L ₁ and L ₂ each independently represent a single bond, a substituted or unsubstituted (C 6 -C 30) arylene, or a substituted or unsubstituted (3 to 30 membered) heteroarylene,
Ar _{1 to} Ar ₄ are each independently substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (3 to 7 membered) heterocycloalkyl, substituted Or represents unsubstituted (C6-C30) aryl, or substituted or unsubstituted (3-30 membered) heteroaryl,
R ₁ and R ₂ are each independently substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (3-7 membered) heterocycloalkyl, substituted Or an unsubstituted (C6-C30) aryl, or a substituted or unsubstituted (3-30 membered) heteroaryl, or linked together, monocyclic or polycyclic (C3-C30) alicyclic or aromatic Forming a family ring,
R ₃ is hydrogen, deuterium, halogen, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (3 to 30 membered) heteroaryl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (3-7 membered) heterocycloalkyl, substituted or unsubstituted (C6-C30) aryl (C1-C30) _{alkyl, -NR 4 R 5, -SiR 6} R 7 Represents R ₈ , cyano, nitro, or hydroxyl, or is linked to adjacent substituent (s) to form a monocyclic or polycyclic (C3-C30) alicyclic or aromatic ring;
R ₄ and R ₅ are each independently hydrogen, deuterium, halogen, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl, or substituted or unsubstituted (3-30 Member) represents heteroaryl,
R _{6 to} R ₈ are each independently hydrogen, deuterium, halogen, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (3 to 30 members) ) Represents a heteroaryl, substituted or unsubstituted (3-7 membered) heterocycloalkyl, or substituted or unsubstituted (C3-C30) cycloalkyl, or linked to adjacent substituent (s) monocyclic Or a polycyclic (C3-C30) alicyclic or aromatic ring, the carbon atom (s) of which may be replaced with at least one heteroatom selected from nitrogen, oxygen, and sulfur ,
a represents an integer of 1 to 4, and when a is an integer of 2 or more, each of R ₃ may be the same or different;
The heteroaryl (ene) and the heterocycloalkyl each independently contain at least one heteroatom selected from B, N, O, S, P (═O), Si, and P; Organic electroluminescent compound. The compound is represented by Formula 2 below:

_{2. The} organic electroluminescent compound according to claim 1, wherein L ₁ , L ₂ , Ar _{1 to} Ar ₄ , R _{1 to} R ₃ , and a are as described in claim 1. _{L 1, L 2, Ar 1} ~Ar 4, and the substituents in _{R 1 ~R 8 (C1-C30} ) alkyl, the substituted (C3-C30) cycloalkyl, said substituted (3-7 membered) heterocycloalkyl The substituted (C6-C30) aryl (ene), the substituted (3-30 membered) heteroaryl (ene), and the substituted (C6-C30) aryl (C1-C30) alkyl substituents are each independently Deuterium, halogen, cyano, carboxyl, nitro, hydroxyl, (C1-C30) alkyl, halo (C1-C30) alkyl, (C2-C30) alkenyl, (C2-C30) alkynyl, (C1-C30) alkoxy , (C1-C30) alkylthio, (C3-C30) cycloalkyl, (C3-C30) cycloalkenyl, (3-7 membered) heterocycle Broalkyl, (C6-C30) aryloxy, (C6-C30) arylthio, unsubstituted or (C6-C30) aryl-substituted (3-30 membered) heteroaryl, unsubstituted or (3-30 membered) heteroaryl Substituted with (C6-C30) aryl, tri (C1-C30) alkylsilyl, tri (C6-C30) arylsilyl, di (C1-C30) alkyl (C6-C30) arylsilyl, (C1-C30) alkyldi (C6-C30) arylsilyl, amino, mono- or di (C1-C30) alkylamino, mono- or di (C6-C30) arylamino, (C1-C30) alkyl (C6-C30) arylamino, (C1-C30) ) Alkylcarbonyl, (C1-C30) alkoxycarbonyl, (C6-C30) ) Arylcarbonyl, di (C6-C30) arylboronyl, di (C1-C30) alkylboronyl, (C1-C30) alkyl (C6-C30) arylboronyl, (C6-C30) aryl (C1-C30) The organic electroluminescent compound according to claim 1, wherein the organic electroluminescent compound is at least one selected from the group consisting of alkyl and (C1-C30) alkyl (C6-C30) aryl. Where
L ₁ and L ₂ each independently represent a single bond, a substituted or unsubstituted (C 6 -C 12) arylene, or a substituted or unsubstituted (5 to 20 membered) heteroarylene,
Ar _{1 to} Ar ₄ each independently represents a substituted or unsubstituted (C 6 -C 15) aryl;
Do R ₁ and R ₂ each independently represent substituted or unsubstituted (C1-C6) alkyl, substituted or unsubstituted (C6-C20) aryl, or substituted or unsubstituted (5 to 20 membered) heteroaryl? Or linked together to form a monocyclic or polycyclic (C6-C20) alicyclic or aromatic ring,
R ₃ represents or is adjacent to hydrogen, substituted or unsubstituted (C 6 -C 12) aryl, substituted or unsubstituted (C 5 -C 12) cycloalkyl, —NR ₄ R ₅ , or —SiR ₆ R ₇ R _8. Linked to substituent (s) to form a monocyclic or polycyclic (C6-C12) alicyclic or aromatic ring;
R ₄ and R ₅ each independently represents a substituted or unsubstituted (C6-C12) aryl;
R _{6 to} R ₈ each independently represents a substituted or unsubstituted (C1-C6) alkyl;
The said organic electroluminescent compound of Claim 1 in which a represents the integer of 1-2. Where
L ₁ and L ₂ each independently represent a single bond, an unsubstituted (C 6 -C 12) arylene, or an unsubstituted (5-20 membered) heteroarylene,
Ar _{1 to} Ar ₄ each independently represents (C 6 -C 15) aryl unsubstituted or substituted with (C 1 -C 6) alkyl, (C 6 -C 15) aryl, or (5 to 20 membered) heteroaryl. ,
R ₁ and R ₂ are each independently unsubstituted (C1-C6) alkyl; unsubstituted or substituted with (C1-C6) alkyl, (C6-C25) aryl, or (5-20) membered heteroaryl. (C6-C20) aryl; or (5-20 membered) heteroaryl, unsubstituted or substituted with (C6-C12) aryl, or linked to each other, monocyclic or polycyclic (C6- C20) forming an aromatic ring,
R ₃ represents hydrogen, unsubstituted (C 6 -C 12) aryl, unsubstituted (C 5 -C 12) cycloalkyl, —NR ₄ R ₅ , or —SiR ₆ R ₇ R ₈ , or adjacent substituent (s) To form a monocyclic (C6-C12) aromatic ring,
R ₄ and R ₅ each independently represents unsubstituted (C 6 -C 12) aryl;
R _{6 to} R ₈ each independently represents an unsubstituted (C1-C6) alkyl;
The said organic electroluminescent compound of Claim 1 in which a represents the integer of 1-2. The compound represented by Formula 1 is

The organic electroluminescent compound of claim 1, selected from the group consisting of:   An organic electroluminescent device comprising the organic electroluminescent compound according to claim 1.