JP2006241019A - New dendrimer and light-emitting element given by using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dendrimer having high solubility and light emission intensity, controlled in concentration quenching, and given by using a light-emitting pigment as a core. <P>SOLUTION: This new dendrimer is composed of a light-emitting compound having a reactive group (light-emitting pigment such as a squalirium-based compound and a perylene-based compound) and a first to fifth generation dendron which links with the reactive group of the light-emitting compound and is composed of at least one repeating unit expressed by general formula (1) (X<SB>1</SB>is a bonding group; and p is 0 or 1) and a unit expressed by formula (2) (X<SB>2</SB>is a bonding group; and R<SP>1</SP>and R<SP>2</SP>are identical to or different from each other and are each H, a halogen atom, an alkyl, an alkoxy or a hydrocarbon ring) and composing a terminal. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a novel dendrimer in which a light-emitting compound and a dendron are bonded, and a light-emitting element (organic electroluminescence (EL) element) using the same.

  Low molecular weight materials and high molecular weight materials are known as organic EL materials, and low molecular weight materials are formed by vacuum deposition to produce organic EL. On the other hand, with respect to the latter organic EL material, a fluorescent dye having a large emission quantum yield is usually added to the light emitting layer of the organic EL element. Japanese Unexamined Patent Application Publication No. 2004-123595 (Patent Document 1) discloses an azepine compound and an organic EL element containing the azepine compound in a light emitting layer.

  When such a light emitting layer is composed of an organic polymer and a light emitting compound (or fluorescent dye), a phenomenon in which the light emission intensity is not improved even when the content of the light emitting compound is increased, that is, concentration quenching occurs. Moreover, since the luminescent compound usually has low solubility and affinity for a solvent or an organic polymer, the content of the luminescent compound is limited. Furthermore, since the driving voltage for light emission increases with the addition of the light-emitting compound, light cannot be emitted at a low voltage.

  Japanese Patent Application Laid-Open No. 2004-55355 (Patent Document 2) discloses a color conversion filter including a transparent substrate and a dye conversion layer disposed on the transparent substrate and including a matrix resin, a fluorescent conversion dye, and a dendrimer. Has been. This document also describes that a fluorescence conversion dye and a dendrimer are bonded via a covalent bond, and that the fluorescence conversion dye is included in the dendrimer. As the fluorescence conversion dye, a rhodamine dye and a cyanine dye are used. And pyridine dyes, oxazine dyes, coumarin dyes, coumarin dyes, and naphthalimide dyes. Patent Document 2 specifically describes a rhodamine B-dendrimer conjugate in which triphenylethane is used as a core, and rhodamine B and dendrimer are bound to the core. Regarding the binding between other dyes and dendrimers. Is not listed.

  JP-A-2004-99874 (Patent Document 3) discloses a linear part X which is a divalent organic group which may have a substituent, and a trivalent organic which may have a substituent. A unit consisting of a branched portion Y as a group: -X-Y <, wherein the linear portion X contains at least one thienylene structure and is at least partially conjugated with the branched portion. A dendrimer has been disclosed. This document also describes an electronic device element (such as a light emitting device element) using the dendrimer. However, since the dendrimer of Patent Document 2 contains a thienylene structure, the emission color may be limited.

“Synthetic Metals” Vol.102, 1571-1574 (1999) (Non-Patent Document 1) uses a conjugated dendrimer having a core composed of distilbenzene and an end portion being stilbene as a hole transport layer material. An EL element having a two-layer structure using a pyridine polymer as a light emitting material is disclosed. "Chemical Industry" (published by Chemical Industry Co., Ltd.) August issue, pages 26-30 (2001) (non-patent document 2) discloses a multilayer EL device using a fluorinated phenylene dendrimer as an electron transport layer. ing.
JP 2004-123595 A (Claims) JP 2004-55355 A (claims, paragraph numbers [0022] to [0030]) Japanese Patent Laying-Open No. 2004-99874 (Claims, Example 2) `` Synthetic Metals '' Vol.102, 1571-1574 (1999) "Chemical Industry" (published by Chemical Industry Co., Ltd.) August issue, pages 26-30 (2001)

  Accordingly, an object of the present invention is to provide a novel dendrimer capable of reducing concentration quenching and emitting light at a low voltage, and a light emitting element (organic EL element) using the same.

  Another object of the present invention is to provide a novel dendrimer having a high solubility in a solvent and an affinity for an organic polymer and capable of improving the light emission intensity, and a light emitting device using the same.

  Still another object of the present invention is to provide a light emitting device having a low driving voltage and high luminous efficiency.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have found that when a dendron (dendritic side chain) is bound to a luminescent compound (such as a luminescent dye), solubility in a solvent and affinity for an organic polymer are improved. The inventors have found that an organic EL device that can be improved, concentration quenching can be remarkably suppressed, driving voltage is low, and luminous efficiency is high is obtained, and the present invention has been completed.

  That is, the novel dendrimer of the present invention is composed of a luminescent compound having a reactive group and a dendron bonded to the reactive group of the luminescent compound. That is, the luminescent compound and the dendron are directly bonded. In the novel dendrimer of the present invention, since the luminescent compound and dendron are bonded, the solubility of the luminescent compound in the solvent and the affinity for the resin can be improved, and the emission intensity can be increased. Furthermore, concentration quenching can be reduced, and light can be emitted efficiently when contained in a high concentration. Furthermore, the dendron can emit light efficiently even if the driving voltage is low, because the trapping of carriers into the light emitting compound (such as a light emitting dye) is suppressed. Therefore, the new dendrimer can also be referred to as a new dendrimer for a light emitting element or an organic EL.

  In the dendrimer, the dendron is an nth generation (n = 1) composed of at least one repeating unit represented by the following formula (1) and a unit represented by the following formula (2) and constituting a terminal. It may be a dendron of ~ 5).

Wherein X ₁ and X ₂ are each a linking group, p is 0 or 1, and R ¹ and R ² are the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or a hydrocarbon ring group. Show)
In the above formula, R ¹ and R ² may be a t-butyl group or the like. In the dendrimer, the number m of dendron branches from the luminescent compound may be about 1 to 3, and the dendron may be an nth generation (n = 1 to 4) dendron. The luminescent compound may be at least one compound selected from a luminescent dye, a charge transport agent, an electron transport agent, and a hole transport agent. Specifically, the luminescent compound includes condensed polycyclic hydrocarbons (such as perylene compounds), heterocyclic compounds or condensed heterocyclic compounds (squarylium compounds, coumarin compounds, pyrazine compounds, quinacridone compounds, naphthalene compounds, It may be at least one selected from phthalimide compounds, pyromethene compounds, oxadiazole compounds, fluorene compounds, styrylbenzene compounds, cyanine compounds, merocyanine compounds, and the like. In many cases, the luminescent compound is a luminescent dye (or fluorescent dye).

  The present invention is a light emitting device having an organic layer between electrodes, and includes a light emitting device in which the dendrimer is contained in the organic layer. In this light emitting device, the organic layer may be a light emitting layer containing a dendrimer. The light emitting layer may be composed of a dendrimer and at least one polymer.

  In the present invention, since the luminescent compound and the dendron (dendritic side chain) are bonded, concentration quenching can be reduced and light can be emitted at a low voltage. Moreover, the solubility with respect to a solvent and the affinity with respect to an organic polymer are high, and it can improve luminescence intensity greatly. Furthermore, the drive voltage can be reduced because the dendron restricts the carrier from being captured by the luminescent compound. Therefore, an organic EL element with a low driving voltage and high luminous efficiency can be obtained.

[Luminescent compound]
The light-emitting compound may be a fluorescent compound and / or a phosphorescent compound, and may be a charge transport agent, an electron transport agent, and a hole transport agent as long as it has a light-emitting property (particularly a compound capable of emitting light by an electrical action). Also good. Moreover, the luminescent compound should just have a coupling | bond part (namely, reactive group with respect to a dendron) with a dendron (dendritic side chain).

Examples of luminescent compounds (luminescent dyes such as fluorescent or phosphorescent dyes, hereinafter simply referred to as compounds including dyes) include, for example, styryl compounds (styryl benzene compounds, etc.), condensed polycyclic hydrocarbons (rubrene) Compounds, pyrene compounds, chrysene compounds such as dibenzochrysene compounds, perylene compounds, coronene compounds, fluorene compounds), triphenylene compounds (including divinylphenyl-bonded triphenine compounds), nitrogen atoms, oxygen Heterocyclic compounds or condensed heterocyclic compounds containing at least one heteroatom selected from atoms and sulfur atoms (quinacridone compounds such as squarylium compounds, coumarin compounds, pyrazine compounds, quinacridone, dimethylquinacridone, diethylquinacridone, na Phthalimide Compounds (including carbazole-naphthalimide compounds), pyromethene compounds, pyran compounds, carbazole compounds, benzoxazole compounds (including methyl-substituted benzoxazole compounds), benzimidazole compounds, benzothiazole compounds , Rhodamine compounds, cyanine compounds, merocyanine compounds, oxazine compounds, triarylpyrazoline compounds, pyridine compounds (including dipyrazolepyridine compounds and quinkipyridine compounds), bithiazole compounds, etc., dipyriri Rudicyanobenzene compounds, arylamine compounds, boryl compounds (including dimesitylborylanthracene compounds), porphyrin compounds, etc .; metal complexes such as lithium complexes, magnesium Complex, zinc complex, ruthenium complex, copper complex, boron complex, lanthanide complex, oxadiazole-beryllium complex, europium complex (including terbium-substituted europium complex), phosphine-gold complex, Examples include terbium complexes and aluminum complexes (including thiophene-aluminum complexes). These compounds may have a substituent (C _1-4 alkyl group, carbonyl group, dialkylamino group, cyano group, etc.).

  Furthermore, examples of the charge transport agent (compound having charge transport ability) include a bathophenanthroline compound. Examples of the electron transporting agent (electron transporting light emitting compound or electron injecting transporting agent) include oxadiazole compounds.

  Examples of the hole transporting agent (hole transporting luminescent compound or hole injecting transporting agent) include spiro compounds, isoindole compounds (isoindole, polyisoindole, etc.), pyrazoline compounds, triarylamine compounds (triphenyl). Examples thereof include amine compounds), indolocarbazole compounds, chalcogenide compounds, fluorenyl group-containing compounds, and the like.

  Among these luminescent compounds, luminescent dyes such as styrylbenzene compounds, condensed polycyclic hydrocarbons (perylene compounds, fluorene compounds, etc.), heterocyclic compounds or condensed heterocyclic compounds (squarylium compounds, coumarins) Compound, pyrazine compound, quinacridone compound, naphthalimide compound, pyromethene compound, oxadiazole compound, cyanine compound, merocyanine compound, etc.) are often used. In addition, the heterocyclic compound or the condensed heterocyclic compound usually contains at least one hetero atom selected from a nitrogen atom, an oxygen atom and a sulfur atom (particularly a nitrogen atom and an oxygen atom) as a ring constituting atom. In many cases, it has a member ring, and the 5- or 6-member ring may be aromatic or non-aromatic.

  These luminescent compounds have a reactive group. The type of the reactive group is not particularly limited as long as it can be bonded to the dendron. For example, a halogen atom (chlorine, bromine, iodine atom, etc.), a reactive metal atom (lithium atom, etc.), a hydroxyl group or its group Reactive derivative groups (such as lower alkoxy groups), mercapto groups, carboxyl groups or reactive derivative groups thereof (acyl halide groups (haloformyl groups), acid anhydride groups, etc.), amino groups or imino groups, epoxy groups (or glycidyl groups) ), Isocyanate groups and the like. The reactive group may be a hydroxyl group, a carboxyl group or an acid anhydride group. In addition, a reactive group can be introduce | transduced into the luminescent compound which does not have a reactive group using a single or several well-known chemical reaction.

[Dendrimer]
The dendrimer of the present invention (or the dendrimer for a light emitting device) has a structure in which a dendron (a dendritic side chain or a hyperbranched side chain) is bonded to a reactive group of the light emitting compound (core). The dendron may be composed of a non-aromatic group, but preferably has an aromatic group. In addition, the dendron may be bonded to the luminescent compound (core) in a conjugated or non-conjugated relationship, and is usually bonded in a non-conjugated or non-conductive (or non-conductive) relationship. Many. Furthermore, the dendritic structural units constituting the dendron may be bonded to each other in a conjugated or non-conjugated relationship, and are usually bonded in a non-conjugated or non-conductive (or non-conductive) relationship.

The light-emitting compound (core) and the dendron are bonded through the linking group X ₁ of the formula (1), and the free bond that does not include the linking group X ₁ is the unit (2 ) Bond (a bond including a linking group X ₂ ). The reaction between the reactive group of the luminescent compound and the functional group of the dendron includes various reactions, for example, a halogen atom or a reactive metal atom (such as a lithium atom) and an active hydrogen atom (or a functional group having an active hydrogen atom) A hydroxyl group, a carboxyl group, an amino group, an imino group, etc.), a hydroxyl group or a reactive derivative group thereof (such as a lower alkoxy group) or a mercapto group, a halogen atom, a carboxyl group or an acid anhydride group, Reaction with alkoxysilyl group and / or isocyanate group, reaction of carboxyl group or reactive derivative group thereof (acyl halide group, acid anhydride group, etc.) with hydroxyl group, amino group and / or epoxy group, amino Reaction of a group or imino group with a carboxyl group, an epoxy group, and / or an isocyanate group, an epoxy group (or glycine) The reaction of Le group) and a carboxyl group, and / or amino groups, such as reaction with an isocyanate group and a hydroxyl group, and / or amino groups can be exemplified. A coupling reaction using a halogen atom or the like can also be used.

In the formulas (1) and (2), the linking groups X ₁ and X ₂ include a direct bond (p = 0), an oxygen atom (ether bond), a sulfur atom (sulfide bond), a nitrogen atom, an alkylene group (direct Chain or branched C _1-4 alkylene group), alkyleneoxy group [group —RO— or —OR— (where R is a linear or branched C _1-4 alkylene group)], ester bond (—COO -Or -OCO-), an imide bond (including a dicarboxylic acid imide bond), an amide bond, a urethane bond, a urea bond, and the like. These linking groups X ₁ and X ₂ may be the same or different from each other. The linking groups X ₁ and X ₂ are usually a direct bond (p = 0), an ether bond, an alkyleneoxy group [group —RO— or —OR— (where R is a linear or branched C _1-2 alkylene group). )] In many cases. The linking group X ₁ may constitute a dicarboxylic imide bond. In the formula, the coefficient p is 0 or 1.

In the formula (2), R ¹ and R ² are a hydrogen atom, a halogen atom (fluorine, bromine, chlorine or iodine atom), an alkyl group (for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s- Linear or branched C _1-6 alkyl group such as butyl, t-butyl, pentyl, isopentyl, neopentyl, t-pentyl, hexyl group), alkoxy group (for example, methoxy, ethoxy, propoxy, isopropoxy, butoxy) , Isobutoxy, s-butoxy, t-butoxy, linear or branched C _1-6 alkoxy groups such as pentyloxy, isopentyloxy and hexyloxy groups, cyclic hydrocarbon groups (for example, C ₃ such as cyclohexyl) _-8 cycloalkyl group, C _6-10 aryl group such as phenyl group) and the like. Preferred substituents R ¹ and R ² are bulky substituents, for example branched C _3-5 alkyl groups such as a t-butyl group. The substituents R ¹ and R ² may be the same or different.

A typical dendron has at least one unit represented by the formula (1) (at least one repeating unit) and has a regular branched structure, but the hyperbranched structure is not regular. A branch (super-branch) structure may be used. The n-th generation (Gn) dendron can be composed of n repeating units represented by the formula (1) and 2 ⁿ units represented by the formula (2). For example, the first generation (G1) dendron and the two repeating units represented by the formula (1) and the two units represented by the formula (2) are represented by the two formulas (1). The second generation (G2) dendron with the repeating unit and the four units represented by the formula (2), the three repeating units represented by the formula (1), and the eight represented by the formula (2) A third generation (G3) dendron can be configured with the unit. The generation n of the dendron is about 1 to 5 (preferably 1 to 4). The 0th generation (G0) dendron (monomer) can correspond to the unit represented by the formula (2).

  Furthermore, when the valence (or the number of reactive groups) of the chromogenic compound is m, an n-th generation dendrimer having a branch number (or bond number) m can be obtained. The number of branches m is about 1 to 5, usually about 1 to 3. The generation n of the dendrimer may be about 1 to 10, preferably about 1 to 5 (for example, 2 to 5). A preferred dendrimer is an n-th generation (Gn, n = 1 to 5, preferably about 1 to 4 (for example, 2 to 4)) dendrimer having a branch number m = 1, or an n-th generation (Gn , N = 1 to 4, preferably about 2 to 4), and n-th generation (Gn, n = 1 to 4, preferably about 2 to 4) dendrimer with m = 3 branches. Dendrimers are often n-th generation (Gn, n = 2 to 3) dendrimers having a branch number m = 2.

  In addition, when the generation of a dendrimer becomes large, the solubility with respect to a solvent and affinity with an organic polymer can be improved, and emission intensity can also be improved. Furthermore, when the generation of dendrimers is increased, the driving voltage for light emission can be reduced, the concentration quenching can be reduced, and light can be efficiently emitted even when contained in a high concentration. Therefore, the dendrimer of the present invention can be used as a light-emitting material of a light-emitting element, for example, a dye constituting a light-emitting layer of an organic EL element (for example, a film-forming dye or a dopant dye).

  Dendron can be prepared by a known or conventional method, and various books and documents such as Tetrahedron, 58 (2002) 825-843 can be referred to. Dendrimers are also known or commonly used methods, for example, a divergent method in which monomers are sequentially bonded to a core light-emitting compound and branched, a branched dendron is prepared in advance, and the core light-emitting property is obtained. It can be prepared using a convergent method for binding to a compound, a method combining these, and the like. For these reactions, known or conventional reactions such as cross-coupling reactions can be used.

  Among the novel dendrimers (or dendrimers for light-emitting elements) of the present invention, a dendrimer having a second generation dendron can be represented by the following formula, for example.

(In the formula, A represents a residue of the luminescent compound, m represents 1 to 3 branches, and X ₁ , X ₂ , p, R ¹ , and R ² are the same as above)
[Light emitting element]
The light-emitting element (or organic EL element) of the present invention is composed of a pair of electrodes and an organic layer interposed between the electrodes, and the organic layer contains at least the dendrimer (light-emitting dendrimer). The organic layer may be composed of at least one layer. In a typical example, the organic layer is a light emitting layer alone, a combination of a hole transport layer and a light emitting electron transport layer, a light emitting hole transport layer, A combination with an electron transport layer, or a combination of a hole transport layer, a light emitting layer, and an electron transport layer may be used. In a preferred embodiment, the dendrimer is contained in the light emitting layer.

  FIG. 1 is a schematic cross-sectional view showing an example of the organic EL element of the present invention. In this example, the organic EL element includes a transparent electrode (anode) 2 formed on a transparent substrate (glass substrate or the like) 1, a hole transport layer 5 formed on the transparent electrode, and a hole transport layer on the hole transport layer. And the cathode 2 formed on the electron transporting layer 4, the anode 2, the light emitting layer 4 formed on the light emitting layer, the electron transporting layer 6 formed on the light emitting layer, and the cathode 3 formed on the electron transporting layer. The lead wires 9a and 9b are connected to the cathode 3 and the cathode 3, respectively.

  FIG. 2 is a schematic sectional view showing another example of the organic EL element of the present invention. In the organic EL element shown in FIG. 2, an anode buffer layer (hole injection layer) 7 is interposed between the transparent electrode 2 and the hole transport layer 5 in the element shown in FIG. Further, in FIG. 3 showing still another example of the organic EL device of the present invention, the hole transport layer 5 formed on the transparent electrode (anode) 2 and the light emitting property formed on the hole transport layer. An organic EL element having a laminated structure composed of an electron transport layer 8 and a cathode 3 formed on the light-emitting electron transport layer 8 is shown. Furthermore, in the organic EL device shown in FIG. 4, an anode buffer layer (hole injection layer) 7 is interposed between the transparent electrode (anode) 2 and the hole transport layer 5 in the device shown in FIG. .

Among the organic layers, at least a light emitting layer contains the dendrimer. In addition, you may use together another dopant pigment | dye (or luminescent compound) with the said dendrimer. Examples of such dopant dyes (or luminescent compounds) include luminescent compounds such as 2,5-bis (5-tert-butyl-2-benzoxazolyl) -thiophene in addition to the exemplified luminescent compounds. 4- (dicyano C _1-, such as (C _1-6 alkyl-benzoxazolyl) thiophene, Nile red, 4- (dicyanomethylene) -2-methyl-6- (p-dimethylaminostyryl) -4H-pyran ₄ alkylene) -2-C _1-4 alkyl-6- (p-diC _1-4 alkylaminostyryl) -4H-pyran; 1,1,4,4-tetraphenyl-1,3-butadiene (TPB) Tetra C _6-12 aryl-1,3-butadiene; bis (2- (4-C _1-4 alkylphenyl) C ₂ such as 1,4-bis (2- (4-ethylphenyl) ethynyl) benzene _-4 alkynyl) benzene 4,4'-bis (2,2'-diphenyl vinyl) bis biphenyl (2,2'-C _6-12 aryl-vinyl) biphenyl; N, N, N-tris (terphenyl amine) (p -TTA). These luminescent compounds can be used alone or in combination of two or more.

  The light emitting compound may be a polymer. Examples of the polymer light-emitting compound include oligophenylene vinylene tetramer, π-conjugated polymer [eg, fluorene polymer (liquid crystalline chiral substituted fluorene polymer, spiro fluorene polymer, binaphthyl-fluorene copolymer, fluorene-carbazole Copolymer, liquid crystalline dioctyl fluorene polymer, etc.), binaphthalene-containing polymer, disilanylene oligothienylene polymer, silicon blue light emitting copolymer, oxadiazole polymer (oxadiazole-carbazole-naphthalimide copolymer, all Aromatic oxadiazole polymers), PPV polymers (including porphyrin-grafted PPV polymers, dicyanophenylene vinylene-PPV copolymers, etc.), Chenille -Phenylene copolymer, diethylbenzene polymer, acetylene polymer, vinyl-pyridine gel polymer, thiophene light emitting polymer (thiophene-fluorene copolymer, alkylthiophene copolymer, ethylene oxide group-added thiophene polymer, oligothiophene base polymer, etc. ), Coumarin polymers (including carbazoyl methacrylate-coumarin copolymers), carbazoyl cyanoterephthalidene polymers, naphthalimide polymers, aluminum chelate polymers, octafluorobiphenyl group-containing polymers, etc.], σ conjugates Examples thereof include polymer-based polymers (such as polysilane polymers).

  The hole transport layer may contain an organic compound (hole transport agent) having a hole transport function. Examples of the hole transport agent include N, N′-diphenyl-N, N′-bis (3-methyl). Phenyl) -1,1'-biphenyl-4,4'-diamine (TPD), N, N'-diphenyl-N, N'-bis (1-naphthyl) -1,1'-biphenyl-4,4 ' -Diamine (NPD), 1,1-bis [(di-4-tolylamino) phenyl] cyclohexane, N, N, N ', N'-tetra (3-methylphenyl) -1,3-diaminobenzene (PDA) 4,4 ′, 4 ″ -tris (3-methylphenylphenylamino) triphenylamine (m-MTDATA), 4,4 ′, 4 ″ -tris (1-naphthylphenylamino) triphenylamine (1-TNATA) ), 4, 4 ', 4 "-tri (2-naphthylphenylamino) triphenylamine (2-TNATA), 4,4 ′, 4 ″ -tri (N-carbazolyl) triphenylamine (TCTA), 1,3,5-tris [4- (3- Methylphenylphenylamino) phenyl] benzene (m-MTDAPB), aromatic tertiary amines such as triphenylamine; phthalocyanines and the like. As the hole transport agent, a polymer hole transport agent such as polyimide, polysiloxane, triphenylamine polymer, fluorene-containing arylamine polymer, diphenylacetylene polymer, carbazole-thiophene copolymer, and the like may be used. These hole transport agents can be used alone or in combination of two or more.

  In addition, an organic compound or a polymer having a light emitting function may be added to the hole transport layer in order to impart a light emitting function, and an organic compound or a polymer having a light emitting function may be added to the hole transport layer. You may laminate the light emitting layer comprised by these. The electron transport layer can be composed of an organic compound or a polymer having an electron transport function, and may be formed as a light-emitting electron transport layer having both a light-emitting function and an electron transport function.

The electron transport layer may include an organic compound (electron transport agent) having the electron transport function. Examples of the electron transfer agent include oxadiazole derivatives [eg, 2- (4-biphenyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole (PBD), 2,5 -Bis (1-naphthyl) -1,3,4-oxadiazole (BND), 1,3-bis [5- (4-tert-butylphenyl) -1,3,4-oxadiazolyl] benzene (BPOB) 1,3,5-tris [5- (4-tert-butylphenyl) -1,3,4-oxadiazolyl] benzene (TPOB), 1,3,5-tris [5- (1-naphthyl) -1 , 3,4-oxadiazolyl] oxadiazole derivatives having a C _6-20 aryl group optionally having substituents such as benzene (TNOB)]; diphenoquinones [eg, 3,5,3 ′, 5 ′ -Tetra Diphenoquinones optionally having a substituent (such as C _1-10 alkyl group) such as kiss-t-butyldiphenoquinone; 1,2,3,4,5-pentaphenyl-1,3-cyclopentadiene (PPCP); quinolinolato complexes such as tris (8-quinolinolato) aluminum (Alq ₃ ), bis (benzoquinolinolato) beryllium complex, tris (10-hydroxybenzo [h] quinolinolato) beryllium complex; Tris [5- (dimesitylboryl) -2-thienyl] benzene, 5,5′-bis (dimesitylboryl) -2,2′-bithiophene (BMB-2T), 5,5 ″ -bis (dimesitylboryl) -2,2 And thiophenes such as ': 5', 2 ″ -terthiophene (BMB-3T). Of these, oxadiazoles such as TPOB; quinolinolato complexes such as Alq ₃ ; thiophenes such as 1,3,5-tris [5- (dimesitylboryl) -2-thienyl] benzene, BMB-2T and BMB-3T Etc. are often used. As the electron transport agent, a polymer electron transport agent, for example, a fluorene polymer, a urethane polymer, a fluorinated dendrimer compound, or the like may be used. You may use the said electron transport agent individually or in combination of 2 or more types.

Examples of the organic polymer having an electron transport function and / or hole transport function include, for example, vinyl polymers having a hole transport function group and / or an electron transport function group in the main chain or side chain, such as polyphenylene vinylenes [ For example, C _6-12 arylene vinylene which may have a substituent (C _1-10 alkoxy group etc.) such as polyphenylene vinylene, poly (2,5-dimethoxyphenylene vinylene), polynaphthalene vinylene, etc. Compound]; polyphenylenes (especially polyparaphenylenes) [for example, phenylene which may have a substituent (C _1-10 alkoxy group etc.) such as polyparaphenylene, poly2,5-dimethoxyparaphenylene, etc. a homo- or copolymer], poly C _1-20 Arukiruchiofu such polythiophenes [poly (3-alkylthiophene) Yes emission, poly (3-cyclohexyl) poly C _3-20 cycloalkyl thiophenes such as poly (3- (4-n-hexyl-phenyl) thiophene) substituents such as (C _1-10 alkyl group) Thiophenes, such as C _6-20 arylthiophenes, which may be homo- or copolymers]; polyfluorenes such as poly C _1-20 alkyl fluorene; polyvinyl carbazole (eg, poly-N-vinyl carbazole (PVK ); Polystyrenes (eg, poly-4-N, N-diphenylaminostyrene, poly-4- (5-naphthyl-1,3,4-oxadiazole) styrene); poly (meth) acrylamide [eg, , Poly (N- (p-diphenylamino) phenylmethacrylamide), poly (N, N′-diphenyl-N, N′-bis (3-methyl) Vinyl) polymer having a hole transporting functional group and / or an electron transporting functional group in the main chain or side chain thereof, such as a phenyl) -1,1′-biphenyl-4,4′-diaminomethacrylamide) (PTPDMA), etc .; Examples thereof include poly C _1-4 alkylphenyl silanes such as polymethylphenyl silane; polymers having aromatic amine derivatives in the side chain or main chain (for example, polyaniline polymers); or copolymers thereof. These organic polymers having an electron transport function and / or a hole transport function may be used alone or in combination of two or more.

  Examples of the material constituting the anode buffer layer (hole injection layer) include conventional anode buffer layer materials, such as poly (3,4-ethylenedioxythiophene) (PEDOT). PEDOT may be used alone or may be chemically doped with polystyrene sulfonate (PSS). PEDOT doped with PSS is available as “BAYTRON P AI 4083” from Bayer Co., Ltd. in a water / methanol solution state.

  The thickness of the layer constituting the organic EL element (hole transport layer, light emitting layer, electron transport layer, luminescent electron transport layer, etc.) is not particularly limited, and is 5 nm to 1 μm, preferably 10 to 800 nm, more preferably, respectively. It is about 30 to 500 nm, particularly about 50 to 300 nm.

  A transparent conductive film (for example, indium-tin-oxide (ITO) film, tin oxide film, zinc oxide film, aluminum film, etc.) is used for the anode of the organic EL element, and the work function is small as the cathode. A highly conductive metal (for example, magnesium, lithium, aluminum or silver), calcium or the like is used. When using magnesium as a cathode, in order to improve adhesiveness with the film for organic EL elements, you may co-evaporate with a small amount (for example, 1-10 weight%) of silver. Preferred cathodes include magnesium-silver alloy electrodes, aluminum electrodes, calcium electrodes, lithium / aluminum laminated electrodes, lithium fluoride / aluminum laminated electrodes, and the like.

  The layers (hole transport layer, light emitting layer, electron transport layer, luminescent electron transport layer, etc.) constituting the organic EL element are formed by a conventional method such as vapor deposition (vacuum vapor deposition method, etc.), coating or casting (spin Etc.). In addition, when the components of each functional layer such as a hole transport agent, a luminescent compound, and an electron transport agent are inferior in film formability, if necessary, the binder resin and the binder resin can be used as long as the hole transport function, the luminescent property, and the electron transport function are not impaired. You may use together. Examples of the binder resin include various thermoplastic resins [olefin resins such as polyethylene, polypropylene, and ethylene- (meth) acrylate ester copolymers; styrene resins such as polystyrene and rubber-modified polystyrene (HIPS); acrylic resins ( Polymethyl (meth) acrylate or copolymers thereof; vinyl alcohol polymers such as polyvinyl alcohol; vinyl resins such as polyvinyl chloride; polyamide resins such as 6-nylon; polyester resins [polyalkylene terephthalate copolymer Alkylene arylate resins such as polymers (polyethylene terephthalate copolymer, etc.)]; fluorine resins; polycarbonate; polyacetal; polyphenylene ether; polyphenylene sulfide; Ether ketone; Thermoplastic polyimide; Thermoplastic polyurethane; Norbornene polymer, etc.], Thermosetting resin [Phenol resin, Amino resin (Urea resin, Melamine resin, etc.), Thermosetting acrylic resin, Unsaturated polyester resin, Alkyd resin, Diallyl phthalate resin, epoxy resin, silicone resin, etc.] can be used. These binder resins can be used alone or in combination of two or more. As the binder resin, a resin having a film forming ability and a solvent soluble is usually used.

  The ratio of the binder resin in the hole transport layer, the light emitting layer, the electron transport layer, and the light emitting electron transport layer is, for example, 1 to 70% by weight, preferably 5 to 50% by weight, and more preferably about 10 to 30% by weight. There may be.

  The organic EL device of the present invention is formed by using a conventional method, for example, forming the transparent electrode on a transparent substrate, and depositing the coating on the transparent electrode using a coating solution (for example, spin coating). An organic EL device can be manufactured by sequentially forming layers (a hole transport layer, a light emitting layer, an electron transport layer, a light emitting electron transport layer, and an anode buffer layer (hole injection layer)) and forming a cathode on the organic layer. .

  As the substrate, for example, a transparent substrate (for example, a glass plate such as soda glass, non-alkali glass, or quartz glass, a polymer sheet or film such as polyester, polysulfone, or polyethersulfone) can be used. When producing an EL element, a polymer film can be used.

  The dendrimer of the present invention is useful as a light-emitting material because a light-emitting compound and a dendron are bonded. In addition, the light-emitting element (organic EL element) of the present invention is a display of various display devices, for example, a portable information communication device such as a mobile phone, data such as a personal computer, an image processing device (computer system), a television system, or the like. Useful as a device.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. Dendron was prepared according to Tetrahedron, 58 (2002) 825-843.

Synthesis Example 1 (Preparation of G0-Br)
A carbon tetrachloride solution (25 ml) containing 3,5-di (tert-butyl) toluene (4.56 g, 22 mmol) and N-bromosuccinimide (3.9 g, 22 mmol) was refluxed for 4 hours and cooled to room temperature. The solid was filtered. The filtrate was concentrated to obtain a colorless syrupy crude product containing 3,5-di (tert-butyl) benzyl bromide (G0-Br). The crude product was purified by column chromatography (SiO _2, hexane / toluene (volume ratio) = 20/1) to give the desired compound 3,5-di (tert- butyl) benzyl bromide (G0-Br).

Yield: 70%
¹ H-NMR (CDCl ₃ ) δ: 1.33 (s, 18H), 4.52 (s, 2H), 7.23-7.26 (m, 3H).

Synthesis Example 2 (Preparation of G0-NP)
Dry dimethylformamide (DMF, 10 ml) containing 3,5-di (tert-butyl) benzyl bromide (G0-Br) (0.6 g, 1.5 mmol) and potassium phthalimide (0.333 g, 1.8 mmol) The suspension of was heated at 70-75 ° C. for 5 hours. The reaction mixture was cooled to room temperature and water (20 ml) was added. The yellow oil was separated and extracted with dichloromethane (2 × 15 ml). The combined organic layers were dried, filtered and concentrated to yield a yellow syrup that was crystallized from methanol to give the title compound N- (3,5-di (tert-butyl) benzyl) phthalimide (G0) as a white solid. -NP).

Yield: 80%
Melting point: 141-143 ° C
¹ H-NMR (CDCl ₃ ) δ: 1.31 (s, 18H), 4.85 (s, 2H), 7.34-7.36 (m, 3H), 7.69 (dd, J = 5 .2 and 3.2 Hz, 2H), 7.84 (dd, J = 5.2 and 3.2 Hz, 2H)
EIMS (70 eV) m / z (relative intensity): 349 (M ⁺ , 25), 334 (100), 292 (17), 160 (88), 131 (27), 77 (16), 57 (67).

Synthesis Example 3 (Preparation of G0-NH ₂ )
Suspension in which N- (3,5-di (tert-butyl) benzyl) phthalimide (G0-NP, 0.35 g, 1 mmol) and hydrazine monohydrate (0.5 ml) are dispersed in ethanol (10 ml) Was refluxed for 20 minutes to produce a white gelatinous precipitate. After cooling to room temperature, diethyl ether (50 ml) and 20% potassium hydroxide (50 ml) were added. The aqueous layer was washed with diethyl ether (3 × 40 ml). The organic layers were combined and washed with water (2 × 40 ml), and the organic layer was dried over anhydrous sodium sulfate overnight. The crude product was purified by column chromatography (SiO _2, dichloromethane) to give the title compound 3,5-di (tert- butyl) benzylamine (G0-NH _2).

Yield: 70%
¹ H-NMR (CDCl ₃ ) δ: 1.34 (s, 18H), 3.86 (s, 2H), 7.16 (s, 2H), 7.32 (s, 1H)
EIMS (70 eV) m / z (relative intensity): 218 (M ⁺ −H, 4), 203 (29), 162 (23), 133 (29), 57 (100).

Synthesis Example 4 (Preparation of G1-OH)
3,5-di (tert-butyl) benzyl bromide (G0-Br, 3.96 g, 14 mmol), 3,5-dihydroxybenzyl alcohol (0.98 g, 7 mmol), and dry potassium carbonate (4.83 g, 35 mmol) ), 18-crown-6-ether (0.74 g, 2.8 mmol) and dry acetone (150 ml) were heated to reflux under an argon atmosphere and stirred vigorously for 48 hours. The mixture was cooled to dryness under reduced pressure. Water was added to the residue and extracted with dichloromethane. The aqueous layer was washed twice with dichloromethane and the organic layers were combined. The crude product was purified by column chromatography (SiO _2, dichloromethane) to obtain the title compound 3,5-bis [3,5-di (tert- butyl) benzyloxy] to give the benzyl alcohol (G1-OH).

Yield: 70%;
Melting point: 134-136 ° C
¹ H-NMR (CDCl ₃ ) δ: 1.34 (s, 36H), 4.66 (s, 2H), 5.01 (s, 4H), 6.63 (t, J = 2.2 Hz, 1H ), 6.67 (d, J = 2.2 Hz, 2H), 7.27 (d, J = 1.9 Hz, 4H), 7.40 (t, J = 1.9 Hz, 2H)
EIMS (70 eV) m / z (relative intensity): 544 (M ⁺ , 3), 203 (100), 57 (36).

Synthesis Example 5 (Preparation of G1-Br)
To an ether solution (25 ml) of G1-OH (2.1 g, 3.86 mmol), an ether solution (5 ml) of phosphorus tribromide (1.0 g, 3.69 mmol) was slowly added at 0 ° C. The mixture was stirred for 2 hours and slowly quenched with water (10 ml). The organic layer was extracted with ether (2 × 10 ml). The organic layers were combined, washed with brine (10 ml), dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The crude solid product was recrystallized from hexane to obtain the title compound 3,5-bis [3,5-di (tert-butyl) benzyloxy] benzyl bromide (G1-Br) as a white powder.

Yield: 85%
Melting point: 103-105 ° C
¹ H-NMR (CDCl ₃ ) δ: 1.35 (s, 36H), 4.44 (s, 2H), 5.01 (s, 4H), 6.62 (t, J = 2.2 Hz, 1H ), 6.68 (d, J = 2.2 Hz, 2H), 7.27 (d, J = 1.8 Hz, 4H), 7.41 (t, J = 1.8 Hz, 2H)
EIMS (70 eV) m / z (relative intensity): 347 (M ⁺ -(3,5-di-t-butylbenzyl + t-butyl), 4), 203 (100), 57 (41).

Synthesis Example 6 (Preparation of G1-NP)
The title compound N- [3,5-bis [3,5-di (t-butyl) benzyloxy] benzyl] phthalimide (G1--) was used in the same manner as in Synthesis Example 2, except that G1-Br was used instead of G0-Br. NP).

Yield: 94%
Melting point: 196-198 ° C
¹ H-NMR (CDCl ₃ ) δ: 1.33 (s, 36H), 4.81 (s, 2H), 4.96 (s, 4H), 6.59 (t, J = 2.3 Hz, 1H ), 6.71 (d, J = 2.3 Hz, 2H), 7.25 (d, J = 1.8 Hz, 4H), 7.39 (t, J = 1.8 Hz, 2H), 7.71 (Dd, J = 5.6 and 3.2 Hz, 2H), 7.85 (dd, J = 5.6 and 3.2 Hz, 2H)
EIMS (70 eV) m / z (relative intensity): 470 (M ⁺ -(3,5-di-t-butylbenzyl) + H, 24), 203 (100), 57 (32).

Synthesis Example 7 (Preparation of G1-NH ₂ )
The title compound 3,5-bis [3,5-di (t-butyl) benzyloxy] benzylamine (G1-NH ₂ ) was obtained in the same manner as in Synthesis Example 3, except that G1-NP was used instead of G0-NP. Obtained.

Yield: 80%
Melting point: 81-83 ° C
¹ H-NMR (CDCl ₃ ) δ: 1.34 (s, 36H), 3.83 (s, 2H), 5.01 (s, 4H), 6.58 (t, J = 2.3 Hz, 1H ), 6.61 (d, J = 2.3 Hz, 2H), 7.28 (d, J = 1.8 Hz, 4H), 7.41 (t, J = 1.8 Hz, 2H)
EIMS (70 eV) m / z (relative intensity): 544 (MH ⁺ , 19), 469 (16), 380 (18), 340 (27), 203 (100), 57 (94).

Synthesis Example 8 (Preparation of G2-OH)
The title compound 3,5-bis [3,5-bis (3,5-di (t-butyl) benzyloxy) benzyloxy] was synthesized in the same manner as in Synthesis Example 4 except that G1-Br was used instead of G0-Br. Benzyl alcohol (G2-OH) was obtained.

Yield: 70%
Melting point: 69-71 ° C
¹ H-NMR (CDCl ₃ ) δ: 1.34 (s, 72H), 4.64 (d, J = 6.2 Hz, 2H), 5.00 (s, 12H), 6.58 (t, J = 2.2 Hz, 1H), 6.63 (d, J = 2.2 Hz, 2H), 6.65 (t, J = 2.2 Hz, 1H), 6.73 (d, J = 2.2 Hz) , 4H), 7.28 (d, J = 1.8 Hz, 8H), 7.41 (t, J = 1.8 Hz, 4H).

Synthesis Example 9 (Preparation of G2-Br)
Carbon tetrabromide (0.5 g, 1.51 mmol) and triphenylphosphine (0.4 g, 1.51 mmol) were added to a tetrahydrofuran (THF) solution (10 ml) of G2-OH (1.8 g, 1.51 mmol). Added. The mixture was stirred for 40 minutes and some precipitate was observed. Additional carbon tetrabromide (0.25 g, 0.76 mmol) and triphenylphosphine (0.2 g, 0.76 mmol) were added. The reaction mixture was stirred for an additional hour. The reaction was quenched with water (5 ml) and the mixture was extracted with dichloromethane (4 × 30 ml). The organic layers were combined, washed with brine (5 ml), dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The Zan'ara was purified by column chromatography (SiO _2, dichloromethane) to give the title compound 3,5-bis [3,5-bis (3,5-di (tert- butyl) benzyloxy) benzyloxy] benzyl bromide (G2- Br) was obtained.

Yield: 83%
Melting point: 63-65 ° C
¹ H-NMR (CDCl ₃ ) δ: 1.32 (s, 72H), 4.42 (s, 2H), 4.99 (s, 4H), 5.01 (s, 8H), 6.57 ( t, J = 2.2 Hz, 1H), 6.64 (t, J = 2.2 Hz, 2H), 6.65 (d, J = 2.2 Hz, 1H), 6.72 (d, J = 2) .2 Hz, 4H), 7.27 (d, J = 1.8 Hz, 8H), 7.41 (t, J = 1.8 Hz, 4H).

Synthesis Example 10 (Preparation of G2-NP)
The title compound N- [3,5-bis [3,5-bis (3,5-di (t-butyl) benzyloxy) was synthesized in the same manner as in Synthesis Example 2, except that G2-Br was used instead of G0-Br. [Benzyloxy] benzyl] phthalimide (G2-NP) was obtained.

Yield: 90%
Melting point: 85-87 ° C
¹ H-NMR (CDCl ₃ ) δ: 1.33 (s, 72H), 4.79 (s, 2H), 4.96 (s, 4H), 4.99 (s, 8H), 6.55 ( t, J = 2.1 Hz, 1H), 6.62 (t, J = 2.1 Hz, 2H), 6.68 (d, J = 2.1 Hz, 2H), 6.71 (d, J = 2) .1 Hz, 4H), 7.27 (d, J = 1.8 Hz, 8H), 7.40 (t, J = 1.8 Hz, 4H), 7.68 (dd, J = 5.3 and 3. 2 Hz, 2H), 7.82 (dd, J = 5.3 and 3.2 Hz, 2H).

Synthesis Example 11 (Preparation of G2-NH ₂ )
The title compound 3,5-bis [3,5-bis (3,5-di (t-butyl) benzyloxy) benzyloxy] was synthesized in the same manner as in Synthesis Example 3 except that G2-NP was used instead of G0-NP. Benzylamine (G2-NH ₂ ) was obtained.

Yield: 80%
Melting point: 72-74 ° C
¹ H-NMR (CDCl ₃ ) δ: 1.33 (s, 72H), 2.18 (s, 2H), 3.82 (s, 2H), 5.00 (s, 12H), 6.54 ( t, J = 2.5 Hz, 1H), 6.58 (d, J = 2.5 Hz, 2H), 6.65 (t, J = 1.9 Hz, 2H), 6.73 (d, J = 1) .9 Hz, 4H), 7.28 (d, J = 1.8 Hz, 8H), 7.41 (t, J = 1.8 Hz, 4H).

Synthesis Example 12 (Preparation of G3-OH)
The title compound 3,5-bis [3,5-bis [3,5-bis (3,5-di (t-butyl)] was used in the same manner as in Synthesis Example 4 except that G2-Br was used instead of G0-Br. Benzyloxy) benzyloxy] benzyloxy] benzyl alcohol (G3-OH) was obtained.

Yield: 56%
Melting point: 83-85 ° C
¹ H-NMR (CDCl ₃ ) δ: 1.32 (s, 144H), 4.57 (d, J = 5.5 Hz, 2H), 4.99 (s, 28H), 6.56-6.72. (M, 21H), 7.27 (d, J = 1.0 Hz, 16H), 7.39 (t, J = 1.0 Hz, 8H).

Synthesis Example 13 (Preparation of G3-Br)
The title compound 3,5-bis [3,5-bis [3,5-bis (3,5-di (t-butyl)] was synthesized in the same manner as in Synthesis Example 9 except that G3-OH was used instead of G2-OH. Benzyloxy) benzyloxy] benzyloxy] benzyl bromide (G3-Br) was obtained.

Yield: 87%
Melting point: 73-75 ° C
¹ H-NMR (CDCl ₃ ) δ: 1.33 (s, 144H), 4.37 (s, 2H), 5.00 (s, 28H), 6.57-6.73 (m, 21H), 7.27 (d, J = 1.6 Hz, 16H), 7.39 (t, J = 1.6 Hz, 8H).

Synthesis Example 14 (Preparation of G3-NP)
The title compound N- [3,5-bis [3,5-bis [3,5-bis (3,5-di (t]] was used in the same manner as in Synthesis Example 2 except that G3-Br was used instead of G0-Br. -Butyl) benzyloxy) benzyloxy] benzyloxy] benzyl] phthalimide (G3-NP) was obtained.

Yield: 75%
Melting point: 91-93 ° C
¹ H-NMR (CDCl ₃ ) δ: 1.31 (s, 144H), 4.77 (br, 2H), 5.00 (s, 28H), 6.55-6.73 (m, 21H), 7.27 (d, J = 1.7 Hz, 16H), 7.39 (t, J = 1.7 Hz, 8H), 7.62 (dd, J = 5.5 and 3.2 Hz, 2H), 7 .80 (dd, J = 5.5 and 3.2 Hz, 2H).

Synthesis Example 15 (Preparation of G3-NH ₂ )
The title compound 3,5-bis [3,5-bis [3,5-bis (3,5-di (t-butyl)] was synthesized in the same manner as in Synthesis Example 3, except that G3-NP was used instead of G0-NP. Benzyloxy) benzyloxy] benzyloxy] benzylamine (G3-NH ₂ ) was obtained.

Yield: 72%
Melting point: 85-87 ° C
¹ H-NMR (CDCl ₃ ) δ: 1.32 (s, 144H), 3.80 (s, 2H), 4.99 (s, 28H), 6.54-6.73 (m, 21H), 7.27 (d, J = 1.6 Hz, 16H), 7.39 (t, J = 1.6 Hz, 8H).

  The reaction process formula of the dendrimer which contains the dendron which has the halogen atom obtained by the said synthesis example, and a squarylium pigment | dye as a luminescent compound (core) is shown.

Comparative Example 1 (Preparation of OH-SQ)
N-butyl-5-hydroxy-2-methylbenzothiazolium iodide (0.349 g, 1 mmol), 3,4-dibutoxy-3-cyclobutene-1,2-dione (0.113 g, 0.5 mmol), Then, quinoline (0.4 ml) was added to 20 ml of a mixed solvent of 1-butanol / benzene (volume ratio 4: 1) and refluxed for 5 hours to prepare OH-SQ. The precipitated solid was collected by suction filtration. The reaction process formula is shown below.

Melting point:> 300 ° C
¹ H-NMR (CDCl ₃ ) δ: 0.94 (t, J = 7.5 Hz, 6H, H ^a ), 1.41 (sext, J = 7.5 Hz, 4H, H ^b ), 1.66 ( quint, J = 7.5Hz, 4H, H c), 4.15 (t, J = 7.5Hz, 4H, H d), 5.72 (s, 2H, H e), 6.72 (dd, J = 8.3 and 2.0 Hz, 2H, H ^f ), 6.86 (d, J = 2.0 Hz, 2H, H ^g ), 7.61 (d, J = 8.3 Hz, 2H, H ^h) ), 9.92 (s, 2H, H ⁱ ).

Comparative Example 2 (Preparation of G0-SQ)
OH-SQ (0.052 g, 0.1 mmol) prepared in Comparative Example 1, 18-crown-6-ether (0.016 g, 0.06 mmol), and anhydrous potassium carbonate (0.124 g, 0.9 mmol) The DMSO solution (70 ml) was heated to completely dissolve OH-SQ, and then cooled to room temperature. To this solution, 3,5-di (tert-butyl) benzyl bromide (0.141 g, 0.5 mmol) was added and stirred for 4 days under an argon atmosphere. After completion of the reaction, the reaction was quenched with water (50 ml), and the product was extracted with dichloromethane (50 ml × 3). Column chromatography _{(SiO 2, CH 2 Cl 2} : MeOH ( volume ratio) = 25: 1) to give the desired compound (G0-SQ) at. The reaction process formula is shown below.

Melting point:> 300 ° C
¹ H-NMR (CDCl ₃ ) δ: 0.96 (t, J = 7.5 Hz, 6H, H ^b ), 1.33 (s, 36H, H ^a ), 1.40 (sext, J = 7. ^{5Hz, 4H, H c),} 1.73 (quint, J = 7.5Hz, 4H, H d), 3.97 (t, J = 7.5Hz, 4H, H e), 5.06 (s, ^{4H, f), 5.83 (s} , 2H, H g), 6.71 (d, J = 1.7Hz, 2H, H h), 6.87 (dd, J = 8.6 and 1.7Hz , 2H, H ⁱ ), 7.26 (d, J = 1.7 Hz, 4H, H ^j ), 7.38 (d, J = 8.6 Hz, 2H, H ^k ), 7.42 (dd, J = 1.7 and 1.7Hz, 2H, H ^l).

Example 1 (Preparation of G1-SQ)
DMSO solution (70 ml) of OH-SQ (0.052 g, 0.1 mmol), 18-crown-6-ether (0.016 g, 0.06 mmol) and anhydrous potassium carbonate (0.124 g, 0.9 mmol) ) Was heated to completely dissolve OH-SQ, and then cooled to room temperature. To this solution was added 3,5-bis [3,5-di (tert-butyl) benzyloxy] benzyl bromide (0.182 g, 0.3 mmol) and stirred for 4 hours under an argon atmosphere. After completion of the reaction, the reaction was quenched with water (50 ml), and the product was extracted with dichloromethane (50 ml × 3). The target compound (G1-SQ) was obtained by column chromatography (SiO ₂ , CH ₂ Cl ₂ : CH ₃ COCH ₃ (volume ratio) = 20: 1). The reaction process formula is shown below.

Melting point: 126-127 ° C
¹ H-NMR (CDCl ₃ ) δ: 0.96 (t, J = 7.5 Hz, 6H, H ^b ), 1.33 (s, 72H, H ^a ), 1.41 (sext, J = 7. ^{5Hz, 4H, H c),} 1.72 (quint, J = 7.5Hz, 4H, H d), 3.96 (t, J = 7.5Hz, 4H, H e), 5.00 (s, 8H, H ^f ), 5.06 (s, 4H, H ^g ), 5.83 (s, 2H, H ^h ), 6.65 (dd, J = 2.3 Hz, 2H, H ⁱ ), 6. 70 (d, J = 2.3 Hz, 2H, H ^j ), 6.71 (d, J = 2.3 Hz, 4H, H ^k ), 6.82 (dd, J = 8.6 and 2.3 Hz, 2H, H ^l ), 7.27 (d, J = 1.7 Hz, 8H, H ^m ), 7.35 (d, J = 8.6 Hz, 2H, H ⁿ ), 7.41 (dd, J = 1.7 and 1.7Hz, 4H, H ^o).

Example 2 (Preparation of G2-SQ)
DMSO solution (70 ml) of OH-SQ (0.052 g, 0.1 mmol), 18-crown-6-ether (0.016 g, 0.06 mmol) and anhydrous potassium carbonate (0.124 g, 0.9 mmol) ) Was heated to completely dissolve OH-SQ, and then cooled to room temperature. Next, 3,5-bis {3,5-bis [3,5-di (tert-butyl) benzyloxy] benzyloxy} benzyl bromide (0.376 g, 0.3 mmol) was added to this solution, and an argon atmosphere was added. Stir for 4 hours. After completion of the reaction, the reaction was quenched with water (50 ml), and the product was extracted with dichloromethane (50 ml × 3). Column chromatography _{(SiO 2, CH 2 Cl 2} : CH 3 COCH 3 ( volume ratio) = 20: 1) to give the desired compound (G2-SQ) at. The reaction process formula is shown below.

Melting point: 74-75 ° C
¹ H-NMR (CDCl ₃ ) δ: 0.96 (t, J = 7.5 Hz, 6H, H ^b ), 6.81 (dd, J = 8.6 and 2.3 Hz, 2H, H ⁿ ), 1.31 (s, 144H, H ^a ), 7.27 (d, J = 1.7 Hz, 16H, H ^o ), 1.42 (sext, J = 7.5 Hz, 4H, H ^c ), 7. 35 (d, J = 8.6 Hz, 2H, H ^p ), 1.76 (quint, J = 7.5 Hz, 4H, H ^d ), 7.40 (dd, J = 1.7 Hz, 8H, H ^q) ), 3.95 (t, J = 7.5Hz, 4H, H e), 5.00 (s, 24H, H f, H g), 5.03 (s, 4H, H h), 5.83 ^{(s, 2H, H r)} , 6.61 (dd, J = 2.3Hz, 2H, H i), 6.65 (dd, J = 2.3Hz, 4H, H j), 6.67 (d , J = 2.3 Hz, 2H, H ^k ), 6.69 (d, J = 2.3 Hz, 4H, H ^l ), 6.71 (d, J = 2.3 Hz, 8H, H ^m ).

Example 3 (Preparation of G3-SQ)
DMSO solution (70 ml) of OH-SQ (0.052 g, 0.1 mmol), 18-crown-6-ether (0.016 g, 0.06 mmol) and anhydrous potassium carbonate (0.124 g, 0.9 mmol) Was heated to completely dissolve OH-SQ, and then cooled to room temperature. Next, 3,5-bis (3,5-bis {3,5-bis [3,5-di (tert-butyl) benzyloxy] benzyloxy} benzyloxy) benzyl bromide (0.638 g, 0.25 mmol) was added and stirred for 3 hours under an argon atmosphere. The reaction was quenched with water (50 ml) and the product was extracted with dichloromethane (50 ml × 3). The target compound (G3-SQ) was obtained by preparative thin layer chromatography (TLC) (SiO ₂ , CH ₂ Cl ₂ : Et ₂ O (volume ratio) = 50: 1). The reaction process formula is shown below.

Melting point: 44-45 ° C
¹ H-NMR (CDCl ₃ ) δ: 0.97 (t, J = 7.4 Hz, 6H, H ^b ), 6.71-6.72 (m, 14H, H ^m , H ⁿ , H ^o ), ^{1.34 (s, 288H, H a} ), 6.74-6.75 (m, 16H, H p), 1.40-1.44 (m, 4H, H c), 6.83 (d, ^{J = 8.6Hz, 2H, H q} ), 1.71-1.78 (m, 4H, H d), 7.28 (brs, 32H, H r), 3.94-3.97 (m, ^{4H, H e), 7.36 (} d, J = 8.6Hz, 2H, H s), 4.97-5.03 (m, 60H, H f, H g, H h, H i), 7 .41 (brs, 16H, H ^t ), 5.86 (s, 2H, H ^u ), 6.62-6.63 (m, 4H, H ^j ), 6.65 (brs, 2H, H ^k ) , 6.66-6.67 (m, 8H, H l).

Test example 1
When the solubility (25 ° C.) of the obtained dendrimer dyes (OH-SQ, G0-SQ, G1-SQ and G2-SQ) in cyclohexane was examined, OH-SQ: 0 mol / dm ³ , G0-SQ: 0. 00421 × 10 ⁻³ mol / dm ³ , G1-SQ: 20.8 × 10 ⁻³ mol / dm ³ and G2-SQ: 42.6 × 10 ⁻³ mol / dm ³ , and the generation of dendron is increased The solubility of the dye was greatly improved.

Test example 2
When the density | concentration of the obtained dendrimer pigment | dye (G0-SQ, G1-SQ, G2-SQ) was changed and the chloroform solution was prepared and the fluorescence spectrum was measured, the result shown in FIG. 5 was obtained. As shown in FIG. 5, as the dendron generation increases, fluorescence concentration quenching is suppressed.

Test example 3
Polyvinylcarbazole (PVK) 40 mg, 2- (4-biphenyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole (PBD) 40 mg, and a predetermined amount of dye (G0-SQ, G1-SQ, G2-SQ, G3-SQ) were dissolved in 3 ml of toluene to prepare a coating solution. This coating solution was formed to a thickness of about 1000 mm (100 nm) on the ITO film formed on the substrate under spin coating conditions of 1000 rpm for 10 seconds or spin coating conditions for 2000 rpm for 10 seconds. On this coating film, aluminum lithium (AlLi) was formed into a thickness of 1500 mm (150 nm) by vacuum deposition.

The dependency on the dye was examined with the number of moles of the dye added being constant. That is, the amount of each dye was about 2.5 × 10 ⁻⁷ mol, and the relationship between applied voltage and luminance, the relationship between applied voltage and current density, and the relationship between applied voltage and luminous efficiency were examined. The results are shown in FIG. 6, FIG. 7 and FIG.

  As is clear from FIGS. 6 and 7, when the generation of dendron is increased, the luminance is improved and light is emitted with a small applied voltage, and the light emission efficiency is high. Further, the drive voltage of G3-SQ is smaller than that of G2-SQ.

  The reaction process formula of the dendrimer which has the dendron which has the amino group prepared by the synthesis example, and a perylene pigment | dye as a luminescent compound (core) is shown.

Example 4 (Gn-Perys)
To a quinoline dispersion (5 ml) of 3,4,9,10-perylenetetracarboxylic dianhydride (0.05 g, 0.125 mmol), Dendron Gn-NH ₂ (n = 0 to 3, 0.3 mmol) and Zinc acetate (0.0175 g, 0.08 mmol) was added and the mixture was heated at 200 ° C. for 4 hours under an argon atmosphere. After completion of the reaction, the reaction mixture was poured into a saturated aqueous sodium hydrogen carbonate solution (10 ml), extracted with dichloromethane, and the extract was dried over anhydrous sodium sulfate. The crude product was subjected to column chromatography (SiO ₂ , dichloromethane), followed by high performance liquid chromatography (column: Chromatorex-SI (Fuji-Davison Chemical Ltd.), pore size 70 mm (7 nm), particle size 5 μm, 10 × 250 mm, developing solvent: Purified with hexane-isopropyl alcohol 98: 2 (volume ratio) mixed solvent (2 mL / min), detection: UV254 nm, apparatus: Jasco Gulliver series), and the target compound (Gn-Perys: G0-Pery, G1-Pery, G2- Pery and G3-Pery).

(1) G0-Pery: N, N′-bis [3,5-di (tert-butyl) benzyl} -3,4,9,10-perylenetetracarbodiimide Melting point:> 300 ° C.
¹ H-NMR (CDCl ₃ ) δ: 1.32 (s, 36H), 5.40 (s, 4H), 7.35 (d, J = 1.1 Hz, 2H), 7.49 (t, J = 1.1 Hz, 4H), 8.57 (d, J = 8.0 Hz, 4H), 8.68 (d, J = 8.0 Hz, 4H)
Elemental _{analysis: C 54 H 54 N 2 O} 4
Theoretical value: C = 81.58; H = 6.85; N = 3.52.
Found: C = 81.89; H = 6.72; N = 3.38.

(2) G1-Pery: N, N′-bis {3,5-bis [3,5-di (tert-butyl) benzyloxy] benzyl} -3,4,9,10-perylenetetracarbodiimide Melting point: 134 -136 ° C
¹ H-NMR (CDCl ₃ ) δ: 1.31 (s, 72H), 4.97 (s, 8H), 5.39 (s, 4H), 6.60 (t, J = 2.3 Hz, 2H) ), 6.82 (d, J = 2.3 Hz, 4H), 7.25 (d, J = 1.8 Hz, 8H), 7.38 (t, J = 1.8 Hz, 4H), 8.63 (D, J = 7.8 Hz, 4H), 8.71 (d, J = 7.8 Hz, 4H)
Elemental analysis: C ₉₈ H ₁₁₀ N ₂ O ₈
Theoretical value: C = 81.52; H = 7.68; N = 1.94
Found: C = 81.86; H = 7.63; N = 1.93.

(3) G2-Pery: N, N′-bis (3,5-bis {3,5-bis [3,5-di (tert-butyl) benzyloxy] benzyloxy} benzyl) -3,4,9 , 10-Perylenetetracarbodiimide Melting point: 87-89 ° C
¹ H-NMR (CDCl ₃ ) δ: 1.32 (s, 144H), 4.98 (s, 24H), 5.37 (s, 4H), 6.56 (t, J = 1.8 Hz, 2H ), 6.61 (t, J = 1.8 Hz, 4H), 6.71 (d, J = 1.8 Hz, 8H), 6.82 (d, J = 1.8 Hz, 4H), 7.28. (D, J = 1.5 Hz, 16H), 7.39 (t, J = 1.5 Hz, 8H), 8.56 (d, J = 8.1 Hz, 4H), 8.69 (d, J = 8.1Hz, 4H)
Elemental analysis: C ₁₈₆ H ₂₂₂ N ₂ O ₁₆
Theoretical values: C = 81.48; H = 8.16; N = 1.02
Found: C = 81.08; H = 8.26; N = 0.89.

(4) G3-Pery: N, N′-bis [3,5-bis (3,5-bis {3,5-bis [3,5-di (tert-butyl) benzyloxy] benzyloxy} benzyloxy ) Benzyl] -3,4,9,10-perylenetetracarbodiimide Melting point: 79-81 [deg.] C
¹ H-NMR (CDCl ₃ ) δ: 1.31 (s, 288H), 4.95-4.99 (m, 56H), 5.32 (br, 4H), 6.55-6.80 (m 42H), 7.28 (d, J = 1.8 Hz, 32H), 7.39 (t, J = 1.8 Hz, 16H), 8.53 (d, J = 8.2 Hz, 4H), 8 .64 (d, J = 8.2 Hz, 4H)
Elemental analysis: C ₃₆₁ H ₄₄₄ N ₂ O ₃₂
Theoretical value: C = 81.45; H = 8.41; N = 0.53
Found: C = 81.76; H = 8.53; N = 0.48.

Test example 4
When the solubilities (25 ° C.) of the obtained dendrimer dyes (G0-Perry, G1-Perry, G2-Perry and G3-Perry) in hexane, diethyl ether and dichloromethane were examined, the following results were obtained (unit: 10 ⁻⁴ mol / dm ³ ).

  By introducing dendron, the solubility of the perylene compound in the solvent can be improved. In addition, as the dendron generation increased, the solubility of the dye was greatly improved.

Test Example 5
When the concentration of the obtained dendrimer dye Gn-Pery (n = 0 to 3) was changed to prepare a chloroform solution and the fluorescence spectrum was measured, the result shown in FIG. 9 was obtained. As shown in FIG. 9, as the dendron generation increases, the fluorescence concentration quenching is suppressed and the emission intensity also increases.

Test Example 6
In place of the dye of Test Example 3, the same operation as in Test Example 3 was carried out except that 2.7 × 10 ⁻⁷ mol of G0-Perry, G1-Perry, G2-Perry and G3-Perry were used, respectively. An EL element was produced. Using this EL element, the dye dependency of the current density accompanying application of a voltage of 25 V was evaluated. The results are shown in Table 2.

  As is apparent from Table 2, the current density increased as the generation of dendrimers increased.

Example 5 (Gn-QA)
(i) Synthesis of G0-QA Quinacridone (0.312 g, 1 mmol), tetrabutylammonium bromide (0.306 g, 0.95 mmol), and 13.5 g of a 37.5 wt% aqueous potassium hydroxide solution were added to toluene (35 ml). The quinacridone was completely dissolved while heating the mixture to obtain a homogeneous solution. Next, G0-Br (1.128 g, 4 mmol) was added to this solution, and after refluxing for 4 hours, the solvent was distilled off. To the residue was added water (50 ml) and the product was extracted with dichloromethane (50 ml × 3 times). The resulting organic layer was concentrated and purified by column chromatography _{(SiO 2, CH 2 Cl 2} : C 6 H 14 (n- hexane) (volume ratio) = 5: 1) were separated the desired product at. After fractionation, purified G0-QA was obtained by recrystallization using dichloromethane.

(ii) Synthesis of G1-QA, G2-QA, and G3-QA In place of G0-Br, Gn-Br shown in Table 3 is used, and the amount of components used and the recrystallization solvent are shown in Table 3. Except for changing the addition amount and the solvent, G1-QA, G2-QA, and G3-QA were respectively synthesized according to the synthesis method of G0-QA in (i) above.

  The reaction process formula of the dendrimer containing the obtained quinacridone formula is shown.

(1) G0-QA
Melting point:> 300 ° C
¹ H-NMR (CDCl ₃ ) δ: 1.21 (s, 36H), 5.76 (s, 4H), 7.05 (s, 4H), 7.22 (t, J = 7.9 Hz, 2H ), 7.32 (s, 2H), 7.42 (d, J = 7.9 Hz, 2H), 7.63 (t, J = 7.9 Hz, 2H), 8.52 (d, J = 7) .9Hz, 2H), 8.73 (s, 2H)
Elemental analysis: C ₅₀ H ₅₆ N ₂ O ₂
Theoretical value: C = 83.76; H = 7.87; N = 3.91
Found: C = 82.64; H = 8.26; N = 3.60.
(2) G1-QA
Melting point:> 300 ° C
¹ H-NMR (CDCl ₃ ) δ: 1.28 (s, 72H), 4.91 (s, 8H), 5.70 (br, 4H), 6.53 (d, J = 1.8 Hz, 4H ), 6.61 (t, J = 1.8 Hz, 2H), 7.21 (d, J = 1.7 Hz, 8H), 7.26 (t, J = 8.0 Hz, 2H), 7.36. (T, J = 1.7 Hz, 4H), 7.40 (d, J = 8.0 Hz, 2H), 7.65 (t, J = 8.0 Hz, 2H), 8.53 (d, J = 8.0 Hz, 2H), 8.71 (s, 2H)
Elemental _{analysis: C 94 H 112 N 2 O} 6
Theoretical value: C = 82.66; H = 8.26; N = 2.05
Found: C = 81.76; H = 8.70; N = 1.85.
(3) G2-QA
Melting point: 112-113 ° C
¹ H-NMR (CDCl ₃ ) δ: 1.28 (s, 144H), 4.90 (s, 8H), 4.99 (s, 16H), 5.62 (br, 4H), 6.45 ( s, 4H), 6.55-6.57 (m, 6H), 6.63 (d, J = 1.7 Hz, 8H), 7.19 (t, J = 8.0 Hz, 2H), 7. 25 (br s, 16H), 7.35 (d, J = 8.0 Hz, 2H), 7.38 (br s, 8H), 7.60 (t, J = 8.0 Hz, 2H), 8. 50 (d, J = 8.0 Hz, 2H), 8.64 (s, 2H)
Elemental analysis: C ₁₈₂ H ₂₂₄ N ₂ O ₁₄
Theoretical value: C = 82.06; H = 8.84; N = 1.05
Found: C = 81.37; H = 9.02; N = 0.92.
(4) G3-QA
Melting point: 102-103 ° C
¹ H-NMR (CDCl ₃ ) δ: 1.27 (s, 288H), 4.90 (s, 24H), 4.97 (s, 32H), 6.44 (brs, 4H), 6.50 ( brs, 4H), 6.56 (brs, 2H), 6.60 (brs, 8H), 6.62 (brs, 8H), 6.70 (brs, 16H), 7.14 (t, J = 8 0.0 Hz, 2H), 7.25 (brs, 32H), 7.31 (d, J = 8.0 Hz, 2H), 7.37 (brs, 16H), 7.55 (t, J = 8.0 Hz) , 2H), 8.47 (d, J = 8.0 Hz, 2H), 8.62 (s, 2H)
Elemental analysis: C ₃₅₈ H ₄₄₈ N ₂ O ₃₀
Theoretical value: C = 81.76; H = 8.59; N = 0.53
Found: C = 80.77; H = 9.04; N = 0.41.

Test Example 7
The solubility of quinacridone and dendrimer dyes (G0-QA, G1-QA, G2-QA and G3-QA) in toluene was examined. Each dye was added to 2.7 × 10 ⁻⁷ mol in 3 ml of toluene, and the solubility was compared. G0-QA, G1-QA, G2-QA and G3-QA all dissolved, but quinacridone did not dissolve. G0-QA precipitated when allowed to stand, but G1-QA, G2-QA, and G3-QA did not precipitate. As described above, it is apparent that the solubility of quinacridone is improved by the introduction of dendron.

Test Example 8
By performing the same operation as in Test Example 3 except that 2.7 × 10 ⁻⁷ mol of G0-QA, G1-QA, G2-QA and G3-QA was used instead of the dye of Test Example 3, respectively. An EL element was produced. Using this EL element, the dye dependency of the current density accompanying application of a voltage of 25 V was evaluated. The results are shown in Table 4.

  As is clear from Table 4, the current density increased with the generation of dendrimers.

FIG. 1 is a schematic cross-sectional view showing an example of the organic EL element of the present invention. FIG. 2 is a schematic sectional view showing another example of the organic EL element of the present invention. FIG. 3 is a schematic sectional view showing still another example of the organic EL element of the present invention. FIG. 4 is a schematic cross-sectional view showing another example of the organic EL element of the present invention. FIG. 5 is a graph showing changes in fluorescence spectrum intensity depending on the concentrations of the dendrimer dyes (G0-SQ, G1-SQ, G2-SQ) obtained in the comparative example and Examples 1-2. FIG. 6 is a graph showing the relationship between applied voltage and luminance in the dendrimer dyes (G0-SQ, G1-SQ, G2-SQ, and G3-SQ) obtained in the comparative example and Examples 1-3. FIG. 7 is a graph showing the relationship between applied voltage and current density in the dendrimer dyes (G0-SQ, G1-SQ, G2-SQ, and G3-SQ) obtained in the comparative example and Examples 1-3. FIG. 8 is a graph showing the relationship between the applied voltage and the luminous efficiency in the dendrimer dyes (G0-SQ, G1-SQ, G2-SQ and G3-SQ) obtained in the comparative example and Examples 1-3. FIG. 9 is a graph showing changes in fluorescence spectrum intensity depending on the concentration of the dendrimer dye Gn-Pery (n = 0 to 3) obtained in Example 4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Glass substrate 2 ... Anode 3 ... Cathode 4 ... Light emitting layer 5 ... Hole transport layer 6 ... Electron transport layer 7 ... Anode buffer layer 8 ... Luminescent electron transport layer

Claims (9)

  A novel dendrimer composed of a luminescent compound having a reactive group and a dendron bonded to the reactive group of the luminescent compound. The nth generation (n = 1 to 5) in which the dendron is composed of at least one repeating unit represented by the following formula (1) and a unit represented by the following formula (2) and constituting a terminal. The dendrimer according to claim 1, which is a dendron.

Wherein X ₁ and X ₂ are each a linking group, p is 0 or 1, and R ¹ and R ² are the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or a hydrocarbon ring group. Show)   The dendrimer according to claim 1, wherein the dendron branch number m from the luminescent compound is 1 to 3, and the dendron is an nth generation (n = 1 to 4) dendron.   The dendrimer according to claim 1, wherein the luminescent compound is at least one compound selected from a luminescent dye, a charge transport agent, an electron transport agent and a hole transport agent.   Luminescent compounds are perylene compounds, squarylium compounds, coumarin compounds, pyrazine compounds, quinacridone compounds, naphthalimide compounds, pyromethene compounds, oxadiazole compounds, fluorene compounds, styrylbenzene compounds, cyanine The dendrimer according to claim 1, wherein the dendrimer is at least one selected from the group compounds and merocyanine compounds. The dendrimer according to claim 2, wherein R ¹ and R ² are t-butyl groups.   A light-emitting device comprising an organic layer between electrodes, wherein the organic layer contains the dendrimer according to claim 1.   The light emitting device according to claim 7, wherein the organic layer is a light emitting layer containing a dendrimer.   The light emitting device according to claim 8, wherein the light emitting layer comprises a dendrimer and at least one polymer.

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