JP6525381B2 - Novel organic electroluminescent compound and organic electroluminescent device comprising the same - Google Patents

Description

  The present invention relates to novel organic electroluminescent compounds and organic electroluminescent devices comprising the same.

  Electroluminescent (EL) devices are self-emitting devices that have the advantage of providing a wider viewing angle, better contrast ratio, and faster response time. Organic EL devices were first developed by Eastman Kodak by using small aromatic diamine molecules and aluminum complexes as materials to form the light emitting layer (see Appl. Phys. Lett. 51, 913, 1987). .

  The organic EL device generally comprises an anode, a cathode, and an organic layer formed between the two electrodes, and emits light by recombination of holes injected from the anode and electrons injected from the cathode. The organic layer of the organic EL device may be composed of a hole injection layer (HIL), a hole transport layer (HTL), a light emitting layer (EML), an electron transport layer (ETL), an electron injection layer (EIL), etc. Materials used in the layer can be classified into hole injecting materials, hole transporting materials, light emitting materials, electron transporting materials, electron injecting materials and the like.

  The most important factor that determines the luminous efficiency in organic EL devices is the luminescent material. The light emitting material needs to have the following features, high quantum efficiency, high electron and hole mobility, uniform formability of the light emitting material layer, and stability. The light emitting material is classified into a blue light emitting material, a green light emitting material, or a red light emitting material according to a light emitting color, and further includes a yellow light emitting material or an orange light emitting material. Light emitting materials are classified into fluorescent materials (singlet excited state) and phosphorescent materials (triplet excited state) according to the excited state. Initially, fluorescent materials were used in organic EL devices. However, phosphorescent materials have efficiency (luminescence efficiency) for converting electricity to light four times that of fluorescent materials, reducing power consumption and increasing life. Therefore, development of phosphorescent materials is widely performed.

To date, iridium (III) complexes are widely known as phosphorescent materials, and bis (2- (2'-benzothienyl) -pyridinato-N, C3 ') iridium (acetylacetonate) ((acac) ) Ir (btp) ₂ ), tris (2-phenylpyridine) iridium (Ir (ppy) ₃ ), and bis (4,6-difluorophenyl pyridinato-N, C2) picolinatoiridium (Firpic) respectively , Red, green and blue materials.

  Mixtures of dopant / host materials can be used as light emitting materials to improve color purity, light emission efficiency, and stability. When a dopant / host material system is used, the choice of host material is important as the host material greatly affects the efficiency and performance of the light emitting device. In the prior art, 4,4'-N, N'-dicarbazole-biphenyl (CBP) is the most widely known phosphorescent host material. Pioneer (Japan) et al. Used vasocuproin (BCP), aluminum (III) bis (2-methyl-8-quinolinato) (4-phenylphenolate) (BAlq), etc., used in the hole blocking layer as host materials Recently, high performance organic EL devices have been developed by using them.

  Although these phosphorescent host materials provide good luminescent properties, they have the following disadvantages: (1) high temperature deposition treatment in vacuum due to their low glass transition temperature and low thermal stability Their degradation can occur in it. (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 containing phosphorescent host materials provide higher current efficiencies (cd / A) than those containing fluorescent host materials and have higher drive voltages. Therefore, organic EL devices using conventional phosphorescent host materials have no advantage in terms of power efficiency (lm / W). (3) Furthermore, the operating life and luminous efficiency of the organic EL device are not sufficient.

  On the other hand, copper phthalocyanine (CuPc), 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPB), N, N'-diphenyl-N, N'-bis (3- (3) Methylphenyl)-(1,1′-biphenyl) -4,4′-diamine (TPD), 4,4 ′, 4 ′ ′-tris (3-methylphenylphenylamino) triphenylamine (MTDATA), etc. It is used in organic EL devices as a hole injection and transport material. However, organic EL devices containing these materials have low quantum efficiency and short lifetime, which causes thermal stress to be generated between the anode and the hole injection layer when the organic EL device is driven at high current. And thereby dramatically reduce the lifetime of the device. Furthermore, in the organic material used in the hole injection layer, the movement of holes is very large, thus the balance of the hole-electron charge is broken and the quantum efficiency (cd / A) is reduced.

  Therefore, in order to realize the excellent properties of the organic EL device, the material constituting the organic layer in the device, in particular the host or the dopant, should be suitably selected. On the other hand, Korean Patent No. 10-1082144 discloses, as a host, an organic electroluminescent compound containing a specific fused heterocyclic structure. However, the organic EL devices containing the compounds detailed in the above-mentioned publications also have not yet satisfied the power efficiency, the light emission efficiency, the lifetime and the like. Therefore, the present inventors tried to discover organic electroluminescent compounds capable of providing an organic EL device having properties superior to the compounds detailed in the above-mentioned publication, and exhibited high luminous efficiency and excellent device characteristics. We have found compounds that provide devices with

  The object of the present invention is to provide an organic electroluminescent compound having high luminous efficiency, and to provide an organic EL device containing such organic electroluminescent compound and having a long driving life and improved power efficiency and current efficiency. It is to be.

  Korean Patent No. 10-1082144 discloses a compound in which the HOMO site is directly connected to the LUMO site without a connector. This compound is in the form of an indolocarbazole structure, not a benzoindolocarbazole, and exhibits remarkable characteristic differences as a red host. Generally, structures such as triazines, pyridines, pyrimidines, quinolines and the like that bind to indolocarbazole are used as phosphorescent green hosts, and structures such as quinazolines and quinoxalines that bind to benzoindolocarbazole are phosphorescent red host As only with excellent features. Thus, a red light emitting device comprising the material of the present invention provides improved properties as compared to a device comprising an indolocarbazole derivative without phenyl as a connector, supplied by other companies. Furthermore, the compounds of the present invention comprising benzoindolocarbazole linked by a linker to quinoxaline, quinazoline etc. are structurally different in chemical structure from compounds supplied by other companies and have maximized efficiency characteristics.

  The inventors have found that the above mentioned goals can be achieved by the compounds represented by the following formula 1.

During the ceremony
L ₁ represents a substituted or unsubstituted (C6-C30) arylene group,
Ring A or B represents benzene or naphthalene, provided that A and B do not simultaneously represent benzene,
X represents NR ₆ , -CR ₇ R ₈ , O or S,
Y ₁ and _{Y 2} are each independently, -CR ₉ - or -N- represent, _{if Y 1} represents -N-, _{Y 2} is -CR ₉ - represents, _{Y 1} is -CR ₉ - Y ₂ represents -N-,
R _{1 to} R ₅ each independently represent hydrogen, deuterium, halogen, a cyano group, a carboxyl group, a nitro group, a hydroxyl group, a substituted or unsubstituted (C1-C30) alkyl group, a substituted or unsubstituted (C3- C30) cycloalkyl group, substituted or unsubstituted (C3-C30) cycloalkenyl group, substituted or unsubstituted 3 to 7-membered heterocycloalkyl group, substituted or unsubstituted (C6-C30) aryl group, substituted or unsubstituted 3 to 7 30-membered heteroaryl group, a substituted or unsubstituted (C6-C30) aryl amine _group, a _-NR 10 _{R 11} or _-SiR 12 _R 13 _{R 14,} represents,
R ₁ , R ₂ and R ₅ are linked to the adjacent substituent (s) to form a monocyclic or polycyclic (C 3 -C 30) alicyclic or aromatic ring,
R _{6 to} R ₉ each independently represent hydrogen, deuterium, halogen, a substituted or unsubstituted (C1-C30) alkyl group, a substituted or unsubstituted (C6-C30) aryl group, a substituted or unsubstituted 3 to 30 Membered heteroaryl group, substituted or unsubstituted (C3-C30) cycloalkyl group, substituted or unsubstituted 5 to 7 membered heterocycloalkyl group, substituted or unsubstituted (C6-C30) aryl (C1-C30) alkyl group,- NR ₁₀ R ₁₁ , -SiR ₁₂ R ₁₃ R ₁₄ , a cyano group, a nitro group or a hydroxyl group,
R ₁₀ and R ₁₁ each independently represent hydrogen, deuterium, halogen, a substituted or unsubstituted (C1-C30) alkyl group, a substituted or unsubstituted (C6-C30) aryl group, or a substituted or unsubstituted 3 Represents a 30-membered heteroaryl group,
R ₁₂ to R ₁₄ are each independently hydrogen, deuterium, halogen, substituted or unsubstituted (C1-C30) alkyl group, a substituted or unsubstituted (C6-C30) aryl group, a substituted or unsubstituted 3-30 Membered heteroaryl group, a substituted or unsubstituted 5 to 7 membered heterocycloalkyl group, or a substituted or unsubstituted (C3-C30) cycloalkyl group, or linked to an adjacent substituent (s) for substitution or Form an unsubstituted, monocyclic or polycyclic (C3-C30) cycloaliphatic or aromatic ring,
The carbon atom (s) of the alicyclic or aromatic ring may be replaced with at least one heteroatom selected from nitrogen, oxygen and sulfur,
The heteroaryl (ene) group and the heterocycloalkyl group contain at least one hetero atom selected from B, N, O, S, P (= O), Si, and P,
a represents an integer of 1 to 4, and when a is an integer of 2 or more, each R ₁ is the same or different;
When A or B represents benzene, b or c represents an integer of 1 to 4,
When A or B represents naphthalene, b or c represents an integer of 1 to 6, and when b or c is an integer of 2 or more, each R ₂ or each R ₅ is the same or different.

  The organic electroluminescent compounds according to the invention have high luminous efficiency and excellent lifetime properties, so organic EL devices comprising these compounds have a long driving lifetime, as well as good current efficiency and power efficiency.

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

  The present invention relates to an organic electroluminescent compound represented by Formula 1, an organic electroluminescent material comprising the organic electroluminescent compound, and an organic EL device comprising the material.

  In the present specification, “(C 1 -C 30) alkyl (ene)” means linear or branched alkyl (ene) having 1 to 30 carbon atoms, in which the number of carbon atoms is preferably It is 1 to 20, more preferably 1 to 10, and includes methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl and the like. "(C2-C30) alkenyl" means linear or branched alkenyl having 2 to 30 carbon atoms, wherein the number of carbon atoms is preferably 2 to 20, more preferably 2 to 10 And vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-methylbut-2-enyl and the like. "(C2-C30) alkynyl" is a linear or branched alkynyl having 2 to 30 carbon atoms, of 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 3 to 30 carbon atoms, of which the number of carbon atoms is preferably 3 to 20, more preferably 3 to 7 and examples thereof include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like. “3- to 7-membered heterocycloalkyl” is selected from B, N, O, S, P (OO), Si and P, preferably at least one hetero atom selected from O, S and N; It is a cycloalkyl having 3 to 7, preferably 5 to 7 ring skeleton atoms, and includes tetrahydrofuran, pyrrolidine, thiolane, tetrahydropyran and the like. “(C 6 -C 30) aryl (ene)” is a monocyclic ring or a fused ring having 6 to 30 carbon atoms and derived from an aromatic hydrocarbon, of which the number of carbon atoms is preferably Is 6 to 20, more preferably 6 to 15, and phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, phenanthrenyl, anthracenyl, indenyl, triphenylenyl, pyrenyl, tetracenyl, perylenyl, chrysenyl, naphthacenyl, fluoranthenyl etc. It can be mentioned. “3 to 30 membered heteroaryl (ene)” is at least one, preferably 1 to 4 hetero, selected from the group consisting of B, N, O, S, P (= O), Si and P An aryl group having an atom and 3 to 30 ring skeleton atoms, a monocyclic ring or a fused ring condensed with at least one benzene ring, and preferably 3 to 20, more preferably 3 to 15 It may have ring backbone atoms and be partially saturated, and may be formed by linking at least one heteroaryl or aryl group to a heteroaryl group by a single bond (s), furyl, thiophenyl , Pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, triazinyl, tetrazinyl, tri Monocyclic ring heteroaryls, including zolyl, tetrazolyl, furazanyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl and the like, as well as benzofuranyl, benzothiophenyl, isobenzofuranyl, dibenzofuranyl, dibenzothiophenyl, benzimidazolyl, benzothiazolyl, benzoisothi Azolyl, benzoisoxazolyl, benzoxazolyl, isoindolyl, indazolyl, indazolyl, benzothiadiazolyl, quinolyl, isoquinolyl, sinolinyl, quinazolinyl, quinoxalinyl, carbazolyl, phenoxazinyl, phenanthridinyl, benzodioxolyl, etc. Included are fused ring heteroaryls including. "Halogen" includes F, Cl, Br, and I.

In the present specification, "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. A substituted (C1-C30) alkyl group, a substituted (C3-C30) cycloalkyl group, a substituted (C3-C30) cycloalkenyl group in L ₁ , X, Y ₁ , Y ₂ and R _{1 to} R _{5 of the} formula A substituted 3 to 7 membered heterocycloalkyl group, a substituted (C 6 to C 30) aryl (ene) group, a substituted 5 to 30 membered heteroaryl (en) group, a substituted (C 6 to C 30) aryl (C 1 to C 30) alkyl group, Each substituent of a substituted monocyclic or polycyclic (C3-C30) alicyclic or aromatic ring is independently deuterium, halogen, a cyano group, a carboxyl group, a nitro group, a hydroxyl group , (C1-C30) alkyl group, halo (C1-C30) alkyl group, (C2-C30) alkenyl group, (C2-C30) alkynyl group, (C1-C30) alkoxy group, (C1-C3) ) Alkylthio group, (C3-C30) cycloalkyl group, (C3-C30) cycloalkenyl group, 3- to 7-membered heterocycloalkyl group, (C6-C30) aryloxy group, (C6-C30) arylthio group, unsubstituted Or a (C6-C30) aryl group-substituted 3- to 30-membered heteroaryl group, an unsubstituted or 3- to 30-membered heteroaryl group-substituted (C6-C30) aryl group, tri (C1-C30) alkylsilyl Group, tri (C6-C30) arylsilyl group, di (C1-C30) alkyl (C6-C30) arylsilyl group, (C1-C30) alkyldi (C6-C30) arylsilyl group, amino group, mono or di ( C1-C30) alkylamino, mono or di (C6-C30) arylamino, (C1-C30) Alkyl (C1-C30) alkylamino, (C1-C30) alkoxycarbonyl, (C6-C30) arylcarbonyl, di (C6-C30) arylboronyl, di ( (C1-C30) alkylboronyl group, (C1-C30) alkyl (C6-C30) arylboronyl group, (C6-C30) aryl (C1-C30) alkyl group, and (C1-C30) alkyl (C6-C30) And n) at least one selected from the group consisting of aryl groups.

  The compound of Formula 1 is represented by Formula 2 below.

During the ceremony
L ₁ , X, Y ₁ , Y ₂ , R _{1 to} R ₅ , a, b and c are as defined in Formula 1.

  The compound of Formula 1 is represented by Formula 3 below.

During the ceremony
L ₁ , X, Y ₁ , Y ₂ , R _{1 to} R ₅ , a, b and c are as defined in Formula 1.

  The compound of Formula 1 is represented by Formula 4 below.

During the ceremony
L ₁ , X, Y ₁ , Y ₂ , R _{1 to} R ₅ , a, b and c are as defined in Formula 1.

In the compounds of the formulas 1, 2, 3 and 4, preferably, L ₁ represents a (C 6 -C 20) arylene group which is unsubstituted or substituted by a (C 1 -C 6) alkyl group, R _{1 to} R ₅ are And each independently represents hydrogen or a substituted or unsubstituted (C6-C20) aryl group, and each of R _{6 to} R ₉ independently represents a substituted or unsubstituted (C 1 -C 6) alkyl group, or a substituted or unsubstituted Represents an unsubstituted (C6-C20) aryl group.

  The compounds of formula 1 may be selected from the group consisting of the following compounds:

  The organic electroluminescent compounds according to the invention can be prepared by methods known to the person skilled in the art and can, for example, be prepared according to the following reaction scheme 1.

  The invention further provides an organic electroluminescent material comprising an organic electroluminescent compound of formula 1 and an organic electroluminescent device comprising this material. This material may be comprised solely of the organic electroluminescent compound of the invention or may further comprise conventional materials commonly included in organic electroluminescent materials.

  The organic electroluminescent device according to the invention may comprise a first electrode, a second electrode, and at least one organic layer between the first electrode and the second electrode, the organic layer comprising at least One organic electroluminescent compound of Formula 1 is included.

  One of the first electrode and the second electrode may be an anode and the other may be a cathode. The organic layer may include a light emitting layer, and further includes at least one layer 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, and a hole blocking layer. May be included.

  The organic electroluminescent compound of Formula 1 of the present invention may be included as a host material in the light emitting layer. Preferably, the light emitting layer may further comprise at least one dopant and, if necessary, other compounds in addition to the organic electroluminescent compound of formula 1 of the present invention as a second host material.

  The present invention further provides materials for preparing an organic EL device. The material comprises first and second host materials. The first host material comprises the organic electroluminescent compound of the present invention. The first host material and the second host material may be in the range of 1:99 to 99: 1 by weight.

The second host material may be any of the known phosphorescent hosts, and is preferably selected from the group consisting of compounds of formulas 5-9 below.
H-(Cz-L ₄ ) _h- M (5)
_{H- (Cz) i -L 4 -M} (6)

During the ceremony
Cz represents the following structure,

X represents O or S,
R _{21 to} R ₂₄ each independently represent hydrogen, deuterium, halogen, a substituted or unsubstituted (C1-C30) alkyl group, a substituted or unsubstituted (C6-C30) aryl group, a substituted or unsubstituted 5-membered member Or a 30-membered heteroaryl group, or R ₂₅ R ₂₆ R ₂₇ Si— or is linked to an adjacent substituent (s) to form a monocyclic or polycyclic (C5-C30) alicyclic or Forming an aromatic ring, the carbon atom (s) may be replaced with at least one heteroatom selected from nitrogen, oxygen and sulfur,
R _{25 to} R ₂₇ each independently represent a substituted or unsubstituted (C 1 -C 30) alkyl group, or a substituted or unsubstituted (C 6 -C 30) aryl group,
L ₄ represents a single bond, a substituted or unsubstituted (C 6 -C 30) arylene group, or a substituted or unsubstituted 5- or 30-membered heteroarylene group,
M represents a substituted or unsubstituted (C6-C30) aryl group, or a substituted or unsubstituted 5- or 30-membered heteroaryl group,
Y ₁ and Y ₂ each independently represent —O—, —S—, —N (R ₃₁ ) — or —C (R ₃₂ ) (R ₃₃ ) —, and Y ₁ and Y ₂ are simultaneously There is no
R _{31 to} R ₃₃ each independently represent a substituted or unsubstituted (C1-C30) alkyl group, a substituted or unsubstituted (C6-C30) aryl group, or a substituted or unsubstituted 5- or 30-membered heteroaryl group Or linked to adjacent substituent (s) to form a monocyclic or polycyclic (C5-C30) cycloaliphatic or aromatic ring, whose carbon atom (s) is nitrogen R ₃₂ and R ₃₃ may be the same or different, and may be substituted with at least one heteroatom selected from
h and i each independently represent an integer of 1 to 3,
j, k, l and m each independently represent an integer of 0 to 4;
When h, i, j, k, l, or m is an integer of 2 or more, each (Cz-L ₄ ), each (Cz), each R ₂₁ , each R ₂₂ , each R ₂₃ , or each R ₂₄ Are the same or different.

  Specifically, examples of the second host material include the following.

  In the formula, TPS represents triphenylsilyl.

  The dopant is preferably one or more phosphorescent dopants. The phosphorescent dopant material applied to the organic electroluminescent device of the present invention is not particularly limited, but preferably iridium (Ir), osmium (Os), copper (Cu), and platinum ( It can be selected from the complex compounds of Pt), more preferably, from ortho metalated complex compounds of iridium (Ir), osmium (Os), copper (Cu) and platinum (Pt), and still more preferably ortho metalated It may be an iridium complex compound.

  The dopant included in the organic electroluminescent device of the present invention may be selected from the group consisting of the compounds represented by the following formulas 10-12.

During the ceremony
L is selected from the following structures:

R ₁₀₀ represents hydrogen, a substituted or unsubstituted (C1-C30) alkyl group, or a substituted or unsubstituted (C3-C30) cycloalkyl group, and R _{101 to} R ₁₀₉ and R _{111 to} R ₁₂₃ each independently represent Hydrogen, deuterium, halogen, a substituted or unsubstituted (C1-C30) alkyl group, a substituted or unsubstituted (C3-C30) cycloalkyl group, a cyano group, or a substituted or unsubstituted (C 1 -C 30) represents an alkoxy group, wherein R _{120 to} R ₁₂₃ are linked to adjacent substituent (s) to form a fused ring, eg quinoline, and R _{124 to} R ₁₂₇ are each independently Hydrogen, deuterium, halogen, substituted or unsubstituted (C1-C30) alkyl group, or substituted or unsubstituted (C6-C30) aryl group And when R _{124 to} R ₁₂₇ are aryl groups, they link to the adjacent substituent (s) to form a fused ring, eg fluorene, and R _{201 to} R ₂₁₁ are each independently Represents hydrogen, deuterium, halogen, a substituted or unsubstituted (C1-C30) alkyl group, a substituted or unsubstituted (C3-C30) cycloalkyl group, or a (C6-C30) aryl group; , 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 R ₁₀₀ may be the same or different and n is 1 to 3 Represents an integer of

  The phosphorescent dopant materials include the following.

  The organic layer of the organic electroluminescent device of the present invention comprises the organic electroluminescent compound of Formula 1 and may further comprise at least one compound selected from the group consisting of arylamine compounds and styrylarylamine compounds.

  In the organic electroluminescent device of the present invention, the organic layer comprises, in addition to the organic electroluminescent compound of the formula 1, a metal of group 1 of the periodic table, a metal of group 2 a transition metal of period 4, a period 5 It may further include at least one metal selected from the group consisting of transition metals, lanthanides, and organometallics of d orbital transition elements, or at least one complex compound containing the metal.

  In addition, the organic electroluminescent device of the present invention further comprises at least one light emitting layer comprising a blue electroluminescent compound, a red electroluminescent compound or a green electroluminescent compound in addition to the organic electroluminescent compound of the present invention May emit white light, and may further include a yellow or orange light emitting layer, if necessary.

Preferably, in the organic electroluminescent device of the present invention, at least one layer (hereinafter referred to as “surface layer”) selected from a chalcogenide layer, a metal halide layer, and a metal oxide layer has one or both electrodes Yes) can be installed on the inner surface (s) of the Specifically, a chalcogenide (including oxide) layer of silicon or aluminum is placed on the anode surface of the light emitting medium layer, and a metal halide layer or metal oxide layer is placed on the cathode surface of the electroluminescent medium layer Is preferred. This surface layer provides operational stability to the organic electroluminescent device. Preferably, the chalcogenide includes SiO _x (1 ≦ x ≦ 2), AlO _x (1 ≦ x ≦ 1.5), SiON, SiAlON or the like, and the metal halide is LiF, MgF ₂ , CaF ₂ , a rare earth metal The metal oxide includes fluoride and the like, and the metal oxide includes Cs ₂ O, Li ₂ O, MgO, SrO, BaO, CaO and the like.

  Preferably, in the organic electroluminescent device of the present invention, the mixed region of the electron transport compound and the reducible dopant, or the mixed region of the hole transport compound and the oxidizable dopant is on at least one surface of the pair of electrodes. It can be 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 into the luminescent medium. Furthermore, the hole transport compound is oxidized to a cation, thus making it easier to inject and transport holes from the mixed region into the light emitting medium. Preferably, the oxidizing dopants include various Lewis acids and acceptor compounds, and the reducing dopants include alkali metals, alkali metal compounds, alkaline earth metals, rare earth metals, and mixtures thereof. The reducing dopant layer can be used as a charge generating layer to prepare an organic electroluminescent device having two or more light emitting layers and emitting white light.

  In order to form each layer constituting the organic electroluminescent device of the present invention, dry film formation methods such as vacuum evaporation, sputtering, plasma and ion plating, or wet formation such as spin coating, dip coating and flow coating Membrane methods can be used.

  When a wet film formation method is used, a thin layer is formed by dissolving or dispersing materials constituting each layer in a suitable solvent such as ethanol, chloroform, tetrahydrofuran, dioxane or the like. The solvents are not particularly limited as long as the materials constituting each layer are soluble or dispersible in those solvents that do not cause any problem in forming the layer.

  The organic electroluminescent compounds according to the invention, the process for the preparation of the compounds and the luminescence properties of the devices comprising the compounds will now be described in detail with reference to the following examples.

  Example 1 Preparation of Compounds H-61, H-60, H-10, and H-11

1) Preparation of Compound 1-1 Compound A (100.0 g, 356.0 mmol), 1-naphthylboronic acid (51.0 g, 297.0 mmol), tetrakis (triphenylphosphine) palladium (O) (in a flask) Pd (PPh ₃ ) ₄ ) (11.0 g, 9.0 mmol), 2 M K ₂ CO ₃ (500.0 mL), toluene (1000.0 mL), and ethanol (500.0 mL) for 5 hours while refluxing It stirred. After completing the reaction, the organic layer was extracted with ethyl acetate (EA) and dried by removing the remaining moisture with MgSO ₄ . The residue was separated by column chromatography to give compound 1-1 (70.0 g, 72%).

2) Preparation of Compound 1-2 Compound 1-1 (70.0 g, 213.0 mmol), triphenylphosphine (140.0 g, 533.0 mmol), and dichlorobenzene (1.0 L) are dissolved in a flask, The mixture was refluxed at 150 ° C. for 6 hours. After the reaction was complete, the mixture was distilled and triturated with methanol (MeOH) to give compound 1-2 (40.0 g, 64%).

3) Compound 1-3 Preparation Compound 1-2 (20.0g, 67.53mmol), iodobenzene (15.0mL, 135.06mmol), CuI ( 12.0g, 33.77mmol), Cs 2 CO 3 ( 66.0 g, 202.59 mmol), ethylenediamine (EDA) (2.0 mL, 33.77 mmol), and toluene (400.0 mL) were dissolved in the flask and the mixture was refluxed at 120 ° C. for 5 hours. After completing the reaction, the organic layer was extracted with EA and dried by removing the remaining moisture with MgSO ₄ . The residue was separated by column chromatography to give compound 1-3 (15.0 g, 60%).

4) Preparation of Compound 1-4 Compound 1-3 (26.0 g, 69.84 mmol), 2-chloroaniline (11.0 g, 104.77 mmol), palladium (II) acetate (Pd (OAc) ₂ ) (0) .6 g, 2.79 mmol), sodium tert-butoxide (NaOtBu) (16.0 g, 174.6 mmol), tri-tert-butylphosphine (P (t-Bu) ₃ ) (3.0 mL, 5.58 mmol), And toluene (350.0 mL) were dissolved in the flask and the mixture was refluxed at 120 ° C. for 5 hours. After completing the reaction, the organic layer was extracted with EA and dried by removing the remaining moisture with MgSO ₄ . The residue was separated by column chromatography to give compound 1-4 (19.2 g, 66%).

5) Preparation of Compound _{1-5 1-4 (26.0g, 69.84mmol),} Pd (OAc) 2 (0.6g, 2.79mmol), Cs 2 CO 3 (45.0g, 137.49mmol) , Tricyclohexylphosphine tetrafluoroborate (PCy ₃ HBF ₄ ) (1.7 g, 4.58 mmol), and toluene (300.0 mL) were dissolved in the flask and the mixture was refluxed at 120 ° C. for 5 hours. After completing the reaction, the organic layer was extracted with EA and dried by removing the remaining moisture with MgSO ₄ . The residue was separated by column chromatography to give compound 1-5 (15.0 g, 88%).

6) Preparation of Compound 1-6 Compound 1-5 (14.0 g, 36.60 mmol), 1-bromo-3-iodobenzene (15.0 g, 54.91 mmol), CuI (3.5 g, 18.30 mmol) , K ₃ PO ₄ (23.0 g, 109.8 mmol), EDA (3.0 mL, 36.60 mmol), and toluene (183.0 mL) were dissolved in the flask and the mixture was refluxed at 120 ° C. for 5 hours . After completing the reaction, the organic layer was extracted with EA and dried by removing the remaining moisture with MgSO ₄ . The residue was separated by column chromatography to give compound 1-6 (12.4 g, 65%).

7) Preparation of Compound 1-7 Compound 1-6 (12.4 g, 23.07 mmol) is dissolved in tetrahydrofuran (THF) (100.0 mL), and n-butyllithium (n-BuLi) (14) is dissolved therein. .0 mL, 34.61 mmol, 2.5 M in hexane) was added slowly at -78 [deg.] C. After 1 hour, triisopropyl borate (8.0 mL, 34.61 mmol) was added to the mixture. After the mixture was stirred at room temperature for 12 hours, distilled water was added thereto. The organic layer was extracted with EA, dried over MgSO ₄ and distilled under reduced pressure. Recrystallization with EA and hexane gave compound 1-7 (6.0 g, 52%).

8) Preparation of Compound H-61 Compound 1-7 (7.4 g, 14.73 mmol), Compound B (3.0 g, 12.27 mmol), Pd (PPh ₃ ) ₄ (1.4 g, 1) in a flask .23mmol), 2M of _K 2 _CO 3 (30.0mL), toluene (60.0 mL), and ethanol (30.0 mL), and stirred for 5 hours at reflux. The mixture was allowed to cool to room temperature and distilled water was added thereto. The organic layer was extracted with EA and dried over MgSO ₄ . The residue was distilled under reduced pressure and recrystallized with EA and MeOH to give compound H-61 (2.6 g, 32%).

9) in a flask was charged compound H-60, compound 1-7 (10.0g, 17.11mmol), compound _{B (5.3g, 22.24mmol), Pd} (PPh 3) 4 (1.0g, 0 .86mmol), 2M of _K 2 _CO 3 (50.0mL), toluene (100.0 mL), and ethanol (50.0 mL), and stirred for 5 hours at reflux. The mixture was allowed to cool to room temperature and distilled water was added thereto. The organic layer was extracted with EA and dried over MgSO ₄ . The residue was distilled under reduced pressure and recrystallized with EA and MeOH to give compound H-60 (4.1 g, 37%).

10) in a flask was charged compound H-10, compound 1-7 (10.0g, 17.11mmol), compound _{C (3.5g, 14.25mmol), Pd} (PPh 3) 4 (0.8g, 0 .712mmol), 2M of _K 2 _CO 3 (35.0mL), toluene (70.0 mL), and ethanol (35.0 mL), and stirred for 5 hours at reflux. The mixture was allowed to cool to room temperature and distilled water was added thereto. The organic layer was extracted with EA and dried over MgSO ₄ . The residue was distilled under reduced pressure and recrystallized with EA and MeOH to give compound H-10 (7.5 g, 79%).

11) Preparation of Compound H-11 Compound 1-7 (13.0 g, 22.2 mmol), Compound C (4.5 g, 18.6 mmol), Pd (PPh ₃ ) ₄ (1.0 g, 0) in a flask .9mmol), 2M of _K 2 _CO 3 (28.0mL), toluene (60.0 mL), and ethanol (28.0 mL), and stirred for 5 hours at reflux. The mixture was allowed to cool to room temperature and distilled water was added thereto. The organic layer was extracted with EA and dried over MgSO ₄ . The residue was distilled under reduced pressure and recrystallized with EA and MeOH to give compound H-11 (2.5 g, 21%).

  Characteristic data of the compounds prepared in Example 1 are provided in Table 1 below.

Device Example 1: Preparation of an OLED Device by Using an Organic Electroluminescent Compound According to the Invention An organic light emitting diode (OLED) device using the organic electroluminescent compound of the invention was prepared as follows: on a glass substrate for an OLED device Transparent electrode indium tin oxide (ITO) thin film (15 Ω / sq) (Samsung Corning, Republic of Korea), subjected to ultrasonic cleaning sequentially with trichloroethylene, acetone, ethanol and distilled water, and then stored in isopropanol did. Next, the ITO substrate was placed on the substrate holder of the vacuum deposition apparatus. ^{N 1, N 1 '- (} [1,1'- biphenyl] -4,4'-diyl) bis ^{(N 1} - ^{(naphthalen-1-yl)} -N ^{4, N} 4 - diphenyl-1,4 The diamine) was introduced into the cell of the vacuum evaporation apparatus, and then the pressure in the chamber of this apparatus was controlled to 10 ^-6 Torr. Thereafter, current was applied to the cell to evaporate the introduced material, thereby forming a hole injection layer having a thickness of 60 nm on the ITO substrate. Next, N, N'-di (4-biphenyl) -N, N'-di (4-biphenyl) -4,4'-diaminobiphenyl is introduced into another cell of the vacuum deposition apparatus, and the current is applied to that cell. To evaporate the introduced material, thereby forming a hole transport layer having a thickness of 20 nm on the hole injection layer. Compound H-61 was introduced as a host into one cell of the vacuum deposition apparatus, and compound D-87 was introduced as a dopant into another cell. The two materials were evaporated at different rates and the dopant was deposited at a doping level of 4 wt% based on the total weight of host and dopant to form a light emitting layer having a thickness of 30 nm on the hole transport layer. Subsequently, 2- (4- (9,10-di (naphthalen-2-yl) anthracene-2-yl) phenyl) -1-phenyl-1H-benzo [d] imidizole is introduced into one cell. , Lithium quinolinate was introduced into another cell. The two materials were evaporated at the same rate and each deposited at a 50 wt% doping to form an electron transport layer with a thickness of 30 nm on the light emitting layer. Next, lithium quinolinate is 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 150 nm is deposited on the electron injection layer by another vacuum deposition apparatus. I did. Thus, an OLED device was manufactured. All materials used to fabricate OLED devices were purified by vacuum sublimation at 10 ^-6 Torr prior to use.

The OLED device produced exhibited red emission and had a current density of 8.1 mA / cm ^{2 at} 3.5 V and a luminance of 990 cd / m ² . Furthermore, at a luminance of 5,000 units, the time taken to reduce to 90% emission was at least 130 hours.

Device Example 2: Preparation of an OLED Device by Use of an Organic Electroluminescent Compound According to the Invention An OLED device was prepared in the same manner as device example 1 except that compound H-60 was used as a host in the light emitting material.

The OLED device produced exhibited red emission and had a current density of 8.2 mA / cm ² and a brightness of 1050 cd / m ² at 3.4V. Furthermore, at a luminance of 5,000 units, the time taken to reduce to 90% emission was at least 130 hours.

Device Example 3: Preparation of an OLED Device by Use of an Organic Electroluminescent Compound According to the Invention Device Example 1 and Example 1 with the exception that Compound H-10 was used as the host and Compound D-88 was used as the dopant. OLED devices were manufactured in the same manner.

The OLED device produced showed red emission and had a current density of 12.2 mA / cm ² and a luminance of 920 cd / m ² at 3.6V. Furthermore, at a luminance of 5,000 units, the time taken to reduce to 90% emission was at least 110 hours.

Comparative Example 1: Preparation of OLED Device by Using Conventional Luminescent Material An OLED device was manufactured in the same manner as Device Example 1 except that Compound R-1 was used as a host in the luminescent material.

The OLED device produced showed red emission and had a current density of 8.0 mA / cm ² and a luminance of 1000 cd / m ² at 4.7V. Furthermore, at a luminance of 5,000 units, the time taken to reduce to 90% emission was at least 10 hours.

The organic electroluminescent compounds of the present invention have excellent luminous efficiency, and the organic electroluminescent devices comprising the organic electroluminescent compounds of the present invention provide a long driving life, as well as improved current and power efficiencies.

Claims (8)

An organic electroluminescent compound represented by the following formula 1:

During the ceremony
L ₁ represents a substituted or unsubstituted (C6-C30) arylene group,
Ring A or B represents benzene or naphthalene, provided that A and B do not simultaneously represent benzene,
X represents NR ₆ , -CR ₇ R ₈ , O or S,
Y ₁ and _{Y 2} are each independently, -CR ₉ - or -N- represent, _{if Y 1} represents -N-, _{Y 2} is -CR ₉ - represents, _{Y 1} is -CR ₉ - Y ₂ represents -N-,
R _{1 to} R ₅ each independently represent hydrogen, deuterium , a substituted or unsubstituted (C1-C30) alkyl group , a substituted or unsubstituted (C6-C30) aryl group, a substituted or unsubstituted 3-30 membered hetero an aryl group, a substituted or unsubstituted (C6-C30) aryl amine _group, a _-NR 10 _{R 11} or -SiR12R13R14,,
R ₁ , R ₂ and R ₅ are linked to the adjacent substituent (s) to form a monocyclic or polycyclic (C 3 -C 30) alicyclic or aromatic ring,
R _{6 to} R ₈ each independently represent hydrogen, deuterium, halogen, a substituted or unsubstituted (C1-C30) alkyl group, a substituted or unsubstituted (C6-C30) aryl group, a substituted or unsubstituted 3 to 30 It represents membered heteroaryl group or a substituted or unsubstituted (C6-C30) aryl (C1-C30) alkyl group,
Each R ₉ independently represents hydrogen, deuterium, a substituted or unsubstituted (C 1 -C 30) alkyl group, or a substituted or unsubstituted (C 6 -C 30) aryl group,
R ₁₀ and R ₁₁ each independently represent hydrogen, deuterium, halogen, a substituted or unsubstituted (C1-C30) alkyl group, a substituted or unsubstituted (C6-C30) aryl group, or a substituted or unsubstituted 3 Represents a 30-membered heteroaryl group,
R ₁₂ to R ₁₄ are each independently hydrogen, deuterium, halogen, substituted or unsubstituted (C1-C30) alkyl group, a substituted or unsubstituted (C6-C30) aryl group, a substituted or unsubstituted 3-30 Membered heteroaryl group, a substituted or unsubstituted 5 to 7 membered heterocycloalkyl group, or a substituted or unsubstituted (C3-C30) cycloalkyl group, or linked to an adjacent substituent (s) for substitution or Form an unsubstituted, monocyclic or polycyclic (C3-C30) cycloaliphatic or aromatic ring,
The carbon atom (s) of the alicyclic or aromatic ring may be replaced by at least one heteroatom selected from nitrogen, oxygen and sulfur,
The heteroaryl (ene) group and the heterocycloalkyl group contain at least one hetero atom selected from B, N, O, S, P (= O), Si, and P,
a represents an integer of 1 to 4, and when a is an integer of 2 or more, each R ₁ is the same or different;
When A or B represents benzene, b or c represents an integer of 1 to 4,
When A or B represents naphthalene, b or c represents an integer of 1 to 6, and when b or c is an integer of 2 or more, each R ₂ or each R ₅ is the same or different; Luminescent compounds. Said compound of formula 1 is represented by the following formula 2

During the ceremony
The organic electroluminescent compound according to claim 1, wherein L ₁ , X, Y ₁ , Y ₂ , R _{1 to} R ₅ , a, b and c are as described in claim 1. Said compound of formula 1 is represented by the following formula 3

During the ceremony
The organic electroluminescent compound according to claim 1, wherein L ₁ , X, Y ₁ , Y ₂ , R _{1 to} R ₅ , a, b and c are as described in claim 1. Said compound of formula 1 is represented by the following formula 4

During the ceremony
The organic electroluminescent compound according to claim 1, wherein L ₁ , X, Y ₁ , Y ₂ , R _{1 to} R ₅ , a, b and c are as described in claim 1. L ₁ represents a (C 6 -C 20) arylene group which is unsubstituted or substituted by a (C 1 -C 6) alkyl group, and R _{1 to} R ₅ each independently represent hydrogen, or a substituted or unsubstituted (C 6 -C 6) group The C20) aryl group, wherein R _{6 to} R ₉ each independently represent a substituted or unsubstituted (C 1 -C 6) alkyl group, or a substituted or unsubstituted (C 6 -C 20) aryl group. 4. The organic electroluminescent compound according to any one of 4. Said substituted (C1-C30) alkyl group in X ₁ , Y ₁ , Y ₂ , and R _{1 to} R ₅ , said substituted (C 6 -C 30) aryl (ene) group, said substituted 3 to 30 membered heteroaryl (ene) group, the substituent (C6-C30) aryl (C1-C30) alkyl group, and the substituted monocyclic or polycyclic (C3-C30) substituents alicyclic or aromatic ring, Each independently, deuterium , (C1-C30) alkyl group , (C1-C30) alkoxy group , 3 to 30 member heteroaryl group unsubstituted or substituted by (C6-C30) aryl group, unsubstituted or 3 (C6-C30) aryl group substituted with a 30 to 30-membered heteroaryl group, tri (C1-C30) alkylsilyl group, tri (C6-C30) arylsilyl group, di (C1-C30) alkyl (C6-C30) C30) arylsilyl group, (C1-C30) alkyldi (C6-C30) arylsilyl group, amino group, mono or di (C1-C30) alkylamino group, mono or di (C6-C30) arylamino group, (C1 At least one selected from the group consisting of -C30) alkyl (C6-C30) arylamino group , (C6-C30) aryl (C1-C30) alkyl group, and (C1-C30) alkyl (C6-C30) aryl group Tsudea is, as well,
The substituents of the substituted (C6-C30) arylene group in L ₁ are each independently deuterium, (C3-C30) cycloalkyl group, 3 to 7-membered heterocycloalkyl group, unsubstituted or (C6- C30) 3- to 30-membered heteroaryl group substituted with an aryl group, (C6-C30) aryl group substituted with an unsubstituted or 3- to 30-membered heteroaryl group, tri (C1-C30) alkylsilyl group, tri (C6-C30) C6-C30) arylsilyl group, di (C1-C30) alkyl (C6-C30) arylsilyl group, (C1-C30) alkyldi (C6-C30) arylsilyl group, amino group, mono or di (C1-C30) Alkylamino group, mono- or di (C6-C30) arylamino group, (C1-C30) alkyl (C6-C30) arylamino group And at least one selected from the group consisting of (C6-C30) aryl (C1-C30) alkyl group, and (C1-C30) alkyl (C6-C30) aryl group,
The organic electroluminescent compound according to claim 1. Said compound represented by formula 1 is the following compound:

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