KR20080103772A - Organic electroluminescent polymer with triphenyl amine group and organic electroluminescent device manufactured using the same - Google Patents

Abstract

An organic electroluminescent polymer containing a triphenyl amine group is provided to ensure excellent solubility and high luminous efficiency by minimizing the intermolecular interaction and to improve hole injection and transmission property and color purity. An organic electroluminescent polymer is represented by the chemical formula 1. In the chemical formula 1, A1 is a substituted aryl and C2-4 aryl having a hetero ring; A2 is aryl group substituted or unsubstituted with at least one substitution group selected from a group consisting of linear or branched alkyl group and alkoxy group; R is hydrogen or aryl group substituted or unsubstituted with at least one substitution group selected from a group consisting of C1-20 linear or branched alkyl group and alkoxy group; Ar1 is arylamine group substituted or unsubstituted with at least one substitution group selected from a group consisting of C1-20 linear or branched alkyl group and alkoxy group; Ar2 is selected from a group consisting of C6-60 substituted or unsubstituted aromatic compound, and C2-60 substituted or unsubstituted heteroaromatic compound and their combinations; and X is an integer of 1~10,000, Y is an integer of 0~10,000 and Z is an integer of 1~100,000.

Description

Organic electroluminescent polymer with triphenyl amine group and organic electroluminescent device using the same {organic electroluminescent polymer with triphenyl amine group and organic electroluminescent device manufactured using the same}

1 is a cross-sectional view showing a structure of a general organic electroluminescent device manufactured from a substrate / anode / hole transport layer / light emitting layer / electron transport layer / cathode.

2 is a view showing the synthesis reaction overview of the monomer for the electro-molecules represented by M1, M2 and M3 of the present invention.

3 is a view showing the synthesis reaction overview of the monomer for the electro-molecular advertising molecules represented by M4 of the present invention.

4 is a view showing the synthesis reaction overview of the monomer for the electro-molecules represented by M5 of the present invention.

5 is a view showing the luminous efficiency according to the brightness of the device produced by the electro-molecules produced in accordance with Example 1 of the present invention.

6 is a diagram showing the current density according to the voltage of the device manufactured by the electro-molecules produced in accordance with Example 1 of the present invention.

7 is a view showing the luminous efficiency according to the brightness of the device produced by the electroluminescent molecules prepared according to Example 2 of the present invention.

8 is a view showing the luminance according to the voltage of the device produced by the electro-molecules produced in accordance with Example 2 of the present invention.

※ Explanation of code about main part of drawing ※

11 substrate 12 anode

13 hole transport layer 14 light emitting layer

15: electron transport layer 16: cathode

The present invention relates to an organic electroluminescent molecule comprising a triphenyl amine group and an organic electroluminescent device (EL device) using the same, and more particularly, an arylamine capable of simultaneously performing a high luminous efficiency and a hole transport function. Substituted fluorene substituents large enough to suppress intermolecular interactions and excimers, thereby providing excellent thermal stability and high luminous efficiency, while having high solubility and minimizing intermolecular interactions. The present invention relates to an organic electroluminescent molecule containing a special structural unit introduced with an oren-9-diary group and an electroluminescent device using the same.

Recently, due to the rapid growth of the optical communication and multimedia fields, the development into a highly information society has been accelerated. Accordingly, optoelectronic devices using the conversion of photons to electrons or the conversion of electrons to photons have become the core of the modern information electronics industry. Such semiconductor optoelectronic devices can be broadly classified into electroluminescent devices, light receiving devices, and devices in which they are combined.

Until now, most displays are light-receiving, while self-emissive electroluminescence displays are fast response and self-emissive, so they don't need backlighting and have excellent brightness. It is attracting attention as a display element. Such electroluminescent devices are classified into inorganic and organic light emitting devices according to materials for forming a light emitting layer.

Organic electroluminescence (EL) is a phenomenon in which when an electric field is applied to an organic material, electrons and holes are transferred from the cathode and the anode, respectively, to be combined within the material, and the energy generated is emitted as light. The electroluminescence of these organic materials was reported by Pope et al. In 1963, and in 1987 by Tang et al. At Eastmann Kodak, alumina-quinone. Many studies have been conducted since a light emitting device having a multilayer structure having a quantum efficiency of 1% and a luminance of 1000 cd / m 2 at 10 V or less as a device manufactured from a pigment having a π-conjugated structure. They have the advantage of easy synthesis and synthesis of various types of materials and simple color tuning. However, when the processability and thermal stability are low and voltage is applied, Joule heat is generated in the light emitting layer, and as the molecules are rearranged, the device is destroyed and causes problems in the luminous efficiency or life of the device. Substitution is proceeding with the organic electroluminescent device having.

In this regard, FIG. 1 shows a structure of a general organic electroluminescent device made of a substrate / anode / hole transport layer / light emitting layer / electron transport layer / cathode. Referring to FIG. 1, an anode 12 is formed on the substrate 11. The hole transport layer 13, the light emitting layer 14, the electron transport layer 15, and the cathode 16 are sequentially formed on the anode 12. Here, the hole transport layer 13, the light emitting layer 14, and the electron transport layer 15 are organic thin films made of an organic compound. The driving principle of the organic electroluminescent device of the above structure is as follows:

When a voltage is applied between the anode 12 and the cathode 16, holes injected from the anode 12 are moved to the light emitting layer 14 via the hole transport layer 13. On the other hand, electrons are injected into the light emitting layer 14 from the cathode 16 via the electron transport layer 15, and carriers are recombined in the light emitting layer 14 to generate excitons. This exciton is changed from the excited state to the ground state, whereby the fluorescent molecules of the light emitting layer emit light to form an image. The organic electroluminescent device driven on the principle described above is classified into a polymer organic electroluminescent device and a low molecular organic electroluminescent device according to the molecular weight of the material for forming an organic film.

In general, in the case of using a low molecule in forming the organic film, the low molecule is easy to purify and can almost eliminate impurities, and excellent in luminescence properties. However, there is a problem that inkjet printing or spin coating is impossible and the heat resistance is poor, thereby deteriorating or recrystallizing by the driving heat generated when driving the device. On the other hand, when the polymer is used to form the organic film, the energy level is separated into the conduction band and the electrical appliance diagram by the superposition of the π-electron wave function in the polymer backbone, and the band gap energy corresponding to the energy difference is used. The semiconducting properties of the polymer are determined and full color can be achieved. Such polymers are called π-conjugated polymers.

An electroluminescent device using poly (p-phenylenevinylene) (PPV), a polymer having conjugated double bonds, was first introduced in 1990 by a team of professors from RH Friend at the University of Cambridge, UK. After being announced, researches using organic polymers have been actively conducted. The polymer has excellent heat resistance compared to the low molecule, and inkjet printing and spin coating are possible, which makes it easy to increase the size of the display device. By introducing various suitable substituents, polyphenylenevinylene (PPV) derivatives, polythiophene (Pth) derivatives, and the like, which can improve processability and express various colors, have been reported. However, as materials such as polyphenylenevinylene derivatives and polythiophene derivatives, high efficiency red and green light emitting polymer materials can be obtained among the three primary colors of light, but high efficiency blue light emitting polymer materials can be obtained. it's difficult. In addition, polyphenylene derivatives, polyfluorene derivatives, and the like have been reported as blue light emitting polymer materials. Polyphenylene has high oxidation stability and thermal stability, but has a disadvantage of low luminous efficiency and poor solubility.

In the context of such polyfluorene derivatives, US Pat. No. 6,255,449 discloses 9-substituted-2,7-dihalofluorene compounds, and oligomers and polymers thereof, suitable as light emitting materials such as light emitting or carrier transporting layers of light emitting diodes. Is disclosed.

US Patent Nos. 6,309,763 and 6,605,373 introduce electroluminescent copolymers containing florin groups and amine groups in repeat units. According to the patent, such a copolymer is useful as a light emitting layer or a hole transporting layer of an electroluminescent device.

On the other hand, US Patent No. 6,630,566 discloses a polymer comprising N, P, S, AS or SE useful as a light emitting polymer, specifically, a polymer containing a triarylamine repeat unit, US Patent No. 6,887,973 is an anion Electroluminescent polymers are disclosed that contain fluorene or phenylene repeat units and triarylamine units such that the transporter and cation transporter are in one molecule and the first and second bandgaps of different properties are present. In addition, Japanese Patent Laid-Open No. 2003-00199203 discloses an arylamine derivative having a fluorene skeleton.

As described above, researches using polyfluorene derivatives as active blue molecules have been actively conducted. However, minimization of interaction between excitons produced in one molecule and excitons in other molecules, and improvement of injection and transport properties of holes and electrons It has problems such as efficiency improvement, color purity and lifetime improvement.

Therefore, in the present invention, as a result of extensive research to solve the above problems, it has excellent solubility and minimizes intermolecular interactions and has a high luminous efficiency, the hole of the conventional polyfluorene-based (PFs) The discovery of electro-molecules using new arylamine derivatives and the introduction of a special structural unit that significantly improved the injection and delivery properties, color purity and luminous efficiency, and the electroluminescent device using the same, the present invention was completed based on this.

Accordingly, an object of the present invention is to exhibit an excellent luminous efficiency by minimizing intermolecular interactions and easy energy transfer, and to improve the injection and transfer properties of holes, and to produce an organic electroluminescent polymer required to realize high efficiency blue, green and red light emitting polymers. To provide.

Another object of the present invention to provide an electroluminescent device manufactured using the electroluminescent advertising molecule.

The organic electro-adhesive molecule according to the present invention for achieving the above object is characterized in that the organic electro-adhesive molecule represented by the following formula (1), to which a triphenylamine derivative is introduced:

Wherein A ₁ is an aryl group which is unsubstituted or substituted with at least one substituent selected from the group consisting of a linear or branched alkyl group having 1 to 20 carbon atoms and an alkoxy group; An aryl group substituted with at least one substituent selected from the group consisting of a straight or branched chain alkyl group having 1 to 20 carbon atoms and an alkoxy group having at least one hetero atom selected from the group consisting of F, S, N, O, P and Si ; C 2 substituted with at least one substituent selected from the group consisting of a straight or branched chain alkyl group having 1 to 20 carbon atoms and an alkoxy group having at least one hetero atom selected from the group consisting of F, S, N, O, P and Si An aryl group having a heterocycle of -4;

A ₂ is an aryl group which is unsubstituted or substituted with at least one substituent selected from the group consisting of a linear or branched alkyl group having 1 to 20 carbon atoms and an alkoxy group;

R is an aryl group unsubstituted or substituted with at least one substituent selected from the group consisting of hydrogen, a straight or branched chain alkyl group having 1 to 20 carbon atoms, and an alkoxy group;

Ar ₁ is an arylamine group which is unsubstituted or substituted with at least one substituent selected from the group consisting of a linear or branched alkyl group having 1 to 20 carbon atoms and an alkoxy group;

Ar ₂ is selected from the group consisting of C6 to C60 substituted or unsubstituted aromatic compounds, C2 to C60 substituted or unsubstituted heteroaromatic compounds, and combinations thereof; And,

x is an integer of 1-10,000, y is an integer of 0-10,000, z is an integer of 1-100,000.

An electroluminescent device according to the present invention for achieving the above another object has at least one layer comprising the organic electroluminescent molecules between the anode and the cathode, wherein the layer is a hole transport layer or a light emitting layer.

Hereinafter, the present invention will be described in more detail.

As described above, the present invention has excellent thermal stability and high luminous efficiency and excellent solubility and can minimize the intermolecular interaction, and the hole injection and transfer property, which is a disadvantage of the conventional polyfluorene-based (PFs) and Provided are electroluminescent molecules into which triphenylamine groups have been significantly improved in luminous efficiency, and electroluminescent devices using the same.

Organic electro-adhesive molecules according to the present invention are light emitting polymers having properties of excellent thermal stability, light stability, solubility, film formability, excellent hole injection / transfer quality, excellent color purity and high luminous efficiency, and the specific structural unit of the main chain Since it plays a role in breaking the conjugation, it has excellent color purity and has the advantage of simultaneously injecting and transferring holes, which is an inherent property of arylamines, and by introducing a large substituent fluorenyl group The encapsulation of the arylamine having a structure prevents intermolecular excimers and aggregation, and enables intramolecular or intermolecular energy transfer from the short-wave substituent to the main chain, and also to the substituted large The rotational and vibrational modes are suppressed by the fluorenyl group, which serves to greatly reduce nonradiative decay. Organic electroluminescent polymer of the invention exhibits excellent color purity, luminance and luminescent characteristics of high efficiency.

Electromolecules containing the special structural unit according to the present invention is represented by the formula

<Formula 1>

Wherein A ₁ is an aryl group which is unsubstituted or substituted with at least one substituent selected from the group consisting of a linear or branched alkyl group having 1 to 20 carbon atoms and an alkoxy group; An aryl group substituted with at least one substituent selected from the group consisting of a straight or branched chain alkyl group having 1 to 20 carbon atoms and an alkoxy group having at least one hetero atom selected from the group consisting of F, S, N, O, P and Si ; C 2 substituted with at least one substituent selected from the group consisting of a straight or branched chain alkyl group having 1 to 20 carbon atoms and an alkoxy group having at least one hetero atom selected from the group consisting of F, S, N, O, P and Si An aryl group having a heterocycle of -4;

A ₂ is an aryl group which is unsubstituted or substituted with at least one substituent selected from the group consisting of a linear or branched alkyl group having 1 to 20 carbon atoms and an alkoxy group;

R is hydrogen or an aryl group which is unsubstituted or substituted with at least one substituent selected from the group consisting of a straight or branched chain alkyl group having 1 to 20 carbon atoms and an alkoxy group;

Ar ₁ is an arylamine group which is unsubstituted or substituted with at least one substituent selected from the group consisting of a linear or branched alkyl group having 1 to 20 carbon atoms and an alkoxy group;

Ar ₂ is selected from the group consisting of C6 to C60 substituted or unsubstituted aromatic compounds, C2 to C60 substituted or unsubstituted heteroaromatic compounds, and combinations thereof; And,

x is an integer of 1-10,000, y is an integer of 0-10,000, z is an integer of 1-100,000.

Wherein x is an integer from 1 to 10,000, y is an integer from 0 to 10,000, z is an integer from 4 to 100,000, and x / y is preferably 1/19 or more; (x + y): z preferably has a ratio of 5:95 to 20:80.

In addition, the weight average molecular weight of the polymer represented by General formula (1) is an integer of 800-4,000,000, and molecular weight distribution is 1-10.

Preferably, A ₁ may be selected from the following compounds:

On the other hand, representative examples of the aryl group having the heterocycle are as follows, and preferably may be selected from:

.

.

Wherein R 1 and R 2 are the same as or different from each other, and are selected from the group consisting of hydrogen or a linear or branched alkyl group having 1 to 20 carbon atoms and an alkoxy group, and preferably selected from the following compounds.

In Formula 1, R may be hydrogen, or may be selected from the group consisting of a linear or branched alkyl group having 1 to 20 carbon atoms and an alkoxy group as a substituent, and preferably selected from the following compounds.

Meanwhile, Ar ₁ may be preferably selected from the following compounds:

On the other hand, Ar ₂ is preferably,

(Iii) a C6 to C60 substituted or unsubstituted arylene group;

(Ii) a C2 to C60 substituted or unsubstituted heterocyclic arylene group wherein at least one hetero atom selected from the group consisting of N, S, O, P and Si is included in the aromatic ring;

(Iii) a C 6 to C 60 substituted or unsubstituted arylenevinylene group; And

(Iii) selected from the group consisting of combinations thereof

Here, Ar ₂ is a linear or branched alkyl or alkoxy group having 1 to 20 carbon atoms; An aryl group which is unsubstituted or substituted with at least one substituent selected from the group consisting of a linear or branched alkyl group having 1 to 20 carbon atoms and an alkoxy group; Cyano group (-CN); Or a substituent such as a silyl group.

More specifically,

(Iii) when Ar ₂ is a phenylene group or fluorenyl group among the substituted or unsubstituted arylene groups of C6 to C60, representative examples of such compounds are as follows, and may be selected from:

(Ii) where Ar ₂ is a C2-C60 substituted or unsubstituted heterocyclic arylene group, representative examples of such compounds are as follows and may be selected from:

(Iii) When Ar ₂ is a C ₆ to C 60 substituted or unsubstituted arylenevinylene group, representative examples of such compounds are as follows, and may be selected from them.

One of the methods for preparing the organic electro-molecular advertising molecule of the present invention is as follows. That is, after preparing monomers through alkylation reaction, bromination reaction, Grignard reaction, Wittig reaction, etc., organic electroadhesive molecules may be finally prepared through CC coupling reaction such as Yamamoto coupling reaction and Suzuki coupling reaction. Can be. The number average molecular weight of the polymers obtained therefrom is 800 to 4,000,000, and the molecular weight distribution is 1 to 10.

The organic electroluminescent molecules according to the present invention described above will emit light with the lowest band gap in the arylamine moiety. At this time, the 9-aryl-fluorene-9-yl group is substituted with the arylamine group, which emits light, and has excellent thermal stability, oxidation stability and solubility, high glass transition temperature, minimal intermolecular interaction, and easy energy transfer. In addition, the vibration mode may be suppressed to the maximum, and thus may be applied to the blue, green, and red light emitting hosts that exhibit high luminous efficiency.

According to the present invention, the organic electroluminescent molecule is used as a material for forming a light emitting layer or a hole transport layer positioned between a pair of electrodes in the electroluminescent device. The organic electroluminescent device of the present invention may be configured to further include a hole transport layer and an electron transport layer as well as the most common device configuration of the anode / light emitting layer / cathode.

1 is a cross-sectional view illustrating a structure of a general organic electroluminescent device composed of a substrate / anode / hole transport layer / light emitting layer / electron transport layer / cathode. Referring to this, an example of an organic electroluminescent device to which the organic electroluminescent molecule of the present invention is applied is as follows. It can be prepared as follows.

First, a material for the anode 12 electrode is coated on the substrate 11.

Here, the substrate 11 is a substrate used in a conventional organic electroluminescent device, preferably a glass substrate or a transparent plastic substrate excellent in transparency, surface smoothness, ease of handling and waterproof.

In addition, as the material for the anode 12 electrode, indium tin oxide (ITO), tin oxide (SnO ₂ ), zinc oxide (ZnO), or the like, which is transparent and has excellent conductivity, may be used.

Next, the hole transport layer 13 may be formed by vacuum deposition or sputtering on the anode 11 electrode, and the light emitting layer 14 may be formed through a solution coating method such as spin coating or inkjet printing. In addition, the electron transport layer 15 is formed on the light emitting layer 14 before the cathode 16 is formed. At this time, the thickness of the light emitting layer 14 is preferably 5nm ~ 1㎛, preferably 10 ~ 500nm, the thickness of the hole transport layer and the electron transport layer is preferably 10 ~ 10,0001.

Meanwhile, a conventional electron transport layer forming material may be used for the electron transport layer 15.

The hole transport layer 13 and the electron transport layer 15 serves to increase the probability of light emitting coupling in the light emitting polymer by efficiently transporting the carriers to the light emitting polymer. The material for forming the hole transport layer 13 and the electron transport layer 15 usable in the present invention is not particularly limited, but preferably, the material for the hole transport layer 13 is a poly (doped with a poly (styrenesulphonic acid) (PSS) layer. PEDOT: PSS, N, N'-bis (3-methylphenyl) -N, N-diphenyl- [1,1'-biphenyl] -4, which is 3,4-ethylenedioxy-thiophene) (PEDOT), 4'-diamine (TPD) is preferred, and as an electron transport layer material, aluminum trihydroxyquinoline (Alq3), 1,3,4-oxadiazole derivative PBD (2- (4-biphenylyl) -5- phenyl-1,3,4-oxadiazole, TPQ (1,3,4-tris [(3-penyl-6-trifluoromethyl) quinoxaline-2-yl] benzene), which is a quinoxaline derivative, and a triazole derivative.

On the other hand, when the organic electro-adhesive molecule according to the present invention to form a layer through the solution coating method, by blending with polymers having conjugated double bonds, such as other fluorene-based polymers, polyphenylene vinylene-based, polyparaphenylene-based In some cases, binder resins may be mixed and used. Examples of the binder resins include polyvinylcarbazole, polycarbonate, polyester, polyarylate, polystyrene, acrylic polymer, methacryl polymer, polybutyral, polyvinyl acetal, diallyl phthalate polymer, phenol resin, epoxy resin, Silicone resins, polysulfone resins or urea resins, and the like, which may be used individually or in combination.

Optionally, a hole-blocking layer, such as lithium fluoride (LiF), is further formed by vacuum deposition or the like to limit the transfer rate of holes in the light-emitting layer 14 and to bond electron-holes. You can increase the probability.

Finally, a material for the cathode 16 electrode is coated on the electron transport layer 15.

As the cathode forming metal, lithium (Li), magnesium (Mg), calcium (Ca), barium (Ba), aluminum (Al), Al: Li, and the like having a small work function are used.

The organic electroluminescent device according to the present invention may be manufactured in the order as described above, namely anode / hole transport layer / light emitting layer / electron transport layer / cathode, and vice versa, that is, cathode / electron transport layer / light emitting layer / hole transport layer / anode You may manufacture in order.

In addition, the organic electroluminescent molecules according to the present invention can be used not only in the polymer organic electroluminescent device but also in the photoconversion material in the photodiode or in the semiconductor material organic solar cell in the polymer TFT (Thin Film Transistor).

As described above, the organic electro-adhesive molecule according to the present invention is characterized by random arrangement of substituents by introducing a large substituent fluorenyl group into the arylamine group of the chromophore having a special structural unit, and the characteristic that the intermolecular excimer is suppressed to the maximum. Expressed to inhibit aggregation and / or excimer formation. In addition, intramolecular or intermolecular energy transfer from a short-wave substituent or main chain to a chromophore having a special structural unit located at the beginning of the main chain is possible, as well as rotation and vibration modes are suppressed by the substituted large fluorenyl group. It has a great advantage as a blue light emitting unit having excellent color purity with properties of excellent thermal stability, light stability, solubility, film formability and high quantum efficiency by greatly reducing yarn attenuation. Accordingly, the organic electroluminescent molecule of the present invention and the organic electroluminescent device using the same exhibit excellent characteristics such as color purity, brightness and high luminous efficiency.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited thereto. Meanwhile, the compounds referred to as M1 to M5 are monomers for preparing the electroadhesive molecules of the present invention, and are represented by the following structural formulas. The following specific monomers are intended to illustrate the invention and should not be construed as limiting the invention thereto.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited thereto.

Preparation Example 1

-Synthesis of (9- (9,9-dihexylfluoren-2-yl) -2,7-dibromofluoren-9-ol) (1)

3.3 g (137 mmol) of Mg was added to a 500 mL three neck flask, and then 47.1 g (114 mmol) of 9,9-dihexyl-2-bromo fluorene was added dropwise to 200 mL of THF to form a Grignard reagent. The temperature of the reactor was lowered to -40 ° C. or lower, and then 30 g (91 mmol) of 2,7-dibromofluorenone was added under a nitrogen stream, and the temperature was gradually raised to room temperature, followed by stirring for 10 hours. The reaction is poured into water, extracted with diethyl ether and the solvent is blown on a rotary evaporator. Separation by column chromatography gave 45 g (67 mmol, 73%) of 9- (9,9-dihexylfluoren-2-yl) -2,7-dibromofluorene-9-ol (1). .

Preparation Example 2

-Synthesis of (1,2-di (2-methyl) butyloxy benzene) (2)

In a 500 mL round flask, 20 g (91 mmol) of compound catechol and 107 g (436 mmol) of 2-methyl butyl p-toluenesulfonate were dissolved in 200 mL of DMSO, followed by slowly adding 53 g (473 mmol) of potassium tert-butoxide (t-BuOK) equivalent. The reaction is carried out at 70 ° C. for 12 hours. The reaction was poured into 500 mL of water, extracted with methylene chloride, the solvent was removed with a rotary evaporator, and separated by column chromatography using a mixed solvent of hexane and ethyl acetate. 37 g (148 mmol, 81%) of methyl) butyloxybenzene (2) were obtained.

Preparation Example 3

Synthesis of Monomer M1

52.5 g (78 mmol) of the compound (1) obtained in Example 1 and 23.3 g (93 mmol) of the compound (2) obtained in Example 2 were dissolved in 1000 mL of dichloromethane, and the temperature was lowered to 0 ° C. in a 2 L round flask. While stirring, a solution of 7.5 g (78 mmol) of methane sulfonic acid dissolved in 100 mL of dichloromethane is slowly injected, followed by stirring for 2 hours. The reaction is poured into water, extracted with diethyl ether and the solvent is blown on a rotary evaporator. Separation by column chromatography, 2,7-dibromo-9- (9,9-dihexylfluoren-2-yl) -9- (3,4-di (2-methyl) butyloxyphenyl) flu 58.8 g (65 mmol, 83%) of orene (M1) were obtained.

Preparation Example 4

Synthesis of 9- (9,9-dihexylfluoren-2-yl) -9- (3,4-di (2-methyl) butyloxyphenyl) fluorene-2,7-diboronic acid (3)

58.8 g (65 mmol) of M1 was added to a 250 mL round flask, dissolved in THF 60 mL at room temperature, cooled to -70 ° C, and then slowly added 2 equivalents of 2.5 Mn-butyllithium at a low temperature of -70 to -40 ° C for 2 hours. After the reaction, 4 equivalents of triethyl borate are added at the same temperature and stirred for 12 hours. The reaction was poured into 3N-HCl aqueous solution, stirred for 4 hours, extracted with diethyl ether, the solvent was removed with a rotary evaporator, the solidified material was repeatedly washed with toluene, dried and 9,9-di (9). 41.2 g (76%) of 9, dihexyl) fluoren-2-yl-9- (3,4-di (2-methyl) butyloxyphenyl) fluorene-2,7-diboric acid (3) was obtained. .

Preparation Example 5

Synthesis of Monomer M2

Into a 100 mL round flask, 54.3 g (65 mmol) of Compound (3) obtained in Preparation Example 4, 3 equivalents of ethylene glycol and 50 mL of anhydrous toluene were added thereto, followed by installing a Deanstark apparatus and refluxing for 24 hours. Water to remove water, and then recrystallized from hexane to give 9- (9,9-dihexyl) fluoren-2-yl-9- (3,4-di (2-methyl) butyloxyphenyl) florin-2,7- 50.2 g (57 mmol, 87%) of bisboronic glycol ester (M2) were obtained.

Preparation Example 6

Synthesis of Monomer M3

43.7 g (65 mmol) of the compound (1) and 200 g of 9,9-dihexylfluorene were dissolved in 1000 mL of dichloromethane at room temperature in a 2 L round flask, and the temperature was lowered to 0 ° C., and 10 mL of methanesulfonic acid was stirred with dichloromethane. Slowly inject the solution dissolved in 100 mL of methane and stir for 2 hours. The reaction is poured into water and extracted with diethyl ether, then the solvent is blown on a rotary evaporator. Separation by column chromatography gave 37.3 g (38 mmol, 58%) of 9,9-di (9,9-dihexylfluoren-2-yl) -2,7-dibromofluorene (M3). .

Preparation Example 7

2.25 g (2.436 mmol) tris (dibenzylideneacetone) dipalladium (0) (Pd ₂ (dba) ₃ ), 1,1'-bis (diphenylphosphino) ferrocene (dppf) 2.25 g (3.654 mmol) ) And 200 mL of toluene were stirred under a stream of nitrogen for 30 minutes, followed by 25.85 g (81.2 mmol) of 4,4'-dibrom-biphenyl, 20 g (162.4 mmol) of p-anisidine and 20.9 g of sodium tert-butoxide ( 211.13 mmol) is added and reacted at 90 ° C. for 4 hours. 20.9 g (211.13 mmol) of sodium-tert-butoxide were added again, and the reaction was refluxed for 24 hours by raising the oil bath temperature to 130 ° C. Lower the temperature of the reaction to room temperature, add 300 mL of distilled water and extract 400 mL of ethyl acetate. 15 g (21.13 mmol, 26%) of monomer M4 was prepared by removing an organic solvent using a rotary evaporator and separating the mixture by column chromatography using ethyl acetate and a normal hexane mixed solvent.

Preparation Example 8

-Synthesis of (9- (9,9-dihexylfluoren-2-yl) -2-bromofluoren-9-ol) (4)

3.3 g (137 mmol) of Mg was added to a 500 mL three neck flask, and 47.1 g (114 mmol) of 9,9-dihexyl-2-bromofluorene was dissolved in 200 mL of THF at room temperature and slowly added dropwise to make a Grignard reagent. After the temperature of the reactor was lowered to -40 ° C. or lower, 30 g (91 mmol) of 2, bromofluorenone was added under a nitrogen stream, and the temperature was gradually raised to room temperature, followed by stirring for 10 hours. The reaction is poured into water, extracted with diethyl ether and the solvent is blown on a rotary evaporator. Separation by column chromatography gave 43 g (73 mmol, 80%) of 9- (9,9-dihexylfluoren-2-yl) -2-bromofluorene-9-ol (4).

Preparation Example 9

Synthesis of Compound (5)

In a 2 L round flask, 46.3 g (78 mmol) of compound (4) obtained in Preparation Example 8 and 36.8 g (150 mmol) of triphenylamine were dissolved in 1000 mL of dichloromethane at room temperature, and the temperature was decreased to 0 ° C. While stirring, slowly inject a solution of 7.5 g (78 mmol) of methane sulfonic acid in 100 mL of dichloromethane and stir for 2 hours. The reaction is poured into water, extracted with diethyl ether and the solvent is blown on a rotary evaporator. Separation by column chromatography gave 52.5 g (64 mmol, 82%) of compound (5).

Preparation Example 10

Synthesis of Compound (6)

Put 12 mL of DMF into a 100 mL three-necked flask, lower the temperature to 0 ° C. in an ice bath, and slowly inject 2.2 g (14.4 mmol) of POCl ₃ . Stir at 0 ° C. for 3 h and then add 8.0 g (9.6 mmol) of compound (5). The reaction is stirred at 80 ° C. for 12 hours, then poured into iced water and stirred for 30 minutes. After extraction with diethyl ether, neutralization with NaOH, the solvent is blown by rotary evaporator. Separation by column chromatography gave 4.6 g (5.4 mmol, 56%) of compound (6).

Preparation Example 11

Synthesis of Monomer M5

5 g (5.9 mmol) of compound (6) was dissolved in 50 mL of THF in a 100 mL three-necked flask, and the mixture was left under nitrogen stream for 30 minutes, and then 2.0 g (6.5 mmol) of compound (7) (4-Bromobenzyl diethylphosphonate) was injected. Inject slowly using, and then stir at 80 ° C. for 3 hours. The reaction is poured into water and stirred for 30 minutes, then extracted with diethyl ether, then the solvent is blown on a rotary evaporator. Separation by column chromatography gave 3.4 g (4.4 mmol, 74%) of monomer M5.

Example 1 and Example 2

-Synthesis of Electromolecules

Suzuki coupling reaction known as carbon-carbon coupling reaction using monomers M1, M2, M3, M4 and M5 prepared by the methods of Preparation Examples 1 to 11 (see Chemical Reviewa, Vol. 95, 1995, p. 2457-2483) to prepare a copolymer, and its composition and molecular weight are shown in Table 1 below. The weight average molecular weights of the polymer 1 and the polymer 2 using 5 mol% and 10 mol% of M5, a new structural specific monomer, showed high polymerization degree of 370,000 (PDI = 2.55) and 420,000 (PDI = 2.43), respectively. , It belongs to the molecular weight range that can be easily provided by the solution process method.

division Polymer M1 (mol%) M2 (mol%) M3 (mol%) M4 (mol%) M5 (mol%) Molecular Weight (Mw) Molecular Weight (Mn) PDI Example 1 Polymer 1 20 50 20 10 370,000 145,000 2.55 Example 2 Polymer 2 17 50 20 8 5 420,000 173,000 2.43

Examples 3 and 4

-Manufacturing of electroluminescent device

After forming an indium-tin oxide (ITO) electrode on a glass substrate, spin coating PEDOT on top of the ITO electrode to form a thin film and drying the electroluminescence prepared from Examples 1 and 2 By spin coating the polymer for the device to form a light emitting layer of 700 ~ 1000Å thickness. Ba was deposited on the light emitting layer to a thickness of 50 mV and vacuum was deposited again to 1500 mW to produce an electroluminescent device, and the emission characteristics thereof were measured and shown in Table 2 below.

division Light emitting layer Start voltage (V) Highest efficiency (cd / A) Color coordinates (x, y) Example 3 Polymer 1 3.2 3.05 (0.155, 0.191) Example 4 Polymer 2 2.8 2.96 (0.150, 0.164)

Electroluminescent polymers prepared from Examples 1 and 2 were introduced into the basic structure consisting of M1, M2 and M3, M5 having a triphenylamine group developed in the present invention, and M4 having a hole injection and delivery function. It is the electric advertising molecules with improved properties. In the case of the electroluminescent devices manufactured using these, as shown in Table 2, 5 and 6, the organic electroluminescent device using the polymer 1 using 10 mol% of monomer M5 having a triphenylamine group developed in the present invention In this case, the low start voltage was 3.2 V, the highest efficiency was 3.05 cd / A, and the color coordinate at 500 cd / m ² was emitted in the blue region with x, y = (0.155, 0.191). It showed excellent electroluminescent properties such as maximum luminance of 14,000 cd / m ² or more.

In the case of the organic electroluminescent device using Polymer 2 polymerized using 5 mol% of the monomer M5, as shown in Table 2, FIGS. 7 and 8, a low starting voltage of 2.8 V was obtained and the highest efficiency was 2.96 cd / A. The color coordinates at 500 cd / m ² were x, y = (0.150, 0.164), which gave excellent color purity blue light, and showed excellent electroluminescent properties such as the maximum luminance of 10,000 cd / m ² or more. Seemed. Electroluminescent properties of Polymer 2 using 5 mol% M5 are shown in FIGS. 7 and 8.

In the organic electroluminescent devices of Example 3 and Example 4, driving start voltages of 3.2 V and 2.8 V were shown. It comprises a triphenylamine group developed in the present invention It can be seen that the monomer M5 is an effect exhibited because it facilitates the injection of holes.

 In the organic electroluminescent devices of Examples 3 and 4, the high luminous efficiency was obtained by replacing a fluorenyl group, which is a large substituent, at the end of the arylamine having the planarity of M5, which is a special monomer, thereby preventing intermolecular interactions and excimers. It seems to be a phenomenon because it is completely suppressed.

From these results, it can be seen that the polymers developed in the present invention have excellent electroluminescence properties such as luminance, color purity, and efficiency, which are commercial aspects.

As described above, the electro-adhesion molecules incorporating the monomer M5 having the triphenylamine group developed in the present invention have significantly improved hole injection and transfer properties, color purity and luminous efficiency, and due to excellent thermal stability and bulky substituents, Excellent light emission when used as a host material such as blue, green and red of organic electroluminescent device because it has excellent characteristics such as making thin thin film with high solubility and excellent solubility because it can minimize intermolecular interaction. Characteristics can be expressed.

Claims (9)

Organic electro-molecular advertising molecule, characterized in that represented by the formula (1): <Formula 1>

Wherein A ₁ is an aryl group which is unsubstituted or substituted with at least one substituent selected from the group consisting of a linear or branched alkyl group having 1 to 20 carbon atoms and an alkoxy group; An aryl group substituted with at least one substituent selected from the group consisting of a straight or branched chain alkyl group having 1 to 20 carbon atoms and an alkoxy group having at least one hetero atom selected from the group consisting of F, S, N, O, P and Si ; C 2 substituted with at least one substituent selected from the group consisting of a straight or branched chain alkyl group having 1 to 20 carbon atoms and an alkoxy group having at least one hetero atom selected from the group consisting of F, S, N, O, P and Si An aryl group having a heterocycle of -4; A ₂ is an aryl group which is unsubstituted or substituted with at least one substituent selected from the group consisting of a linear or branched alkyl group having 1 to 20 carbon atoms and an alkoxy group; R is hydrogen or an aryl group which is unsubstituted or substituted with at least one substituent selected from the group consisting of a straight or branched chain alkyl group having 1 to 20 carbon atoms and an alkoxy group; Ar ₁ is an arylamine group which is unsubstituted or substituted with at least one substituent selected from the group consisting of a linear or branched alkyl group having 1 to 20 carbon atoms and an alkoxy group; Ar ₂ is selected from the group consisting of C6 to C60 substituted or unsubstituted aromatic compounds, C2 to C60 substituted or unsubstituted heteroaromatic compounds, and combinations thereof; And, x is an integer of 1-10,000, y is an integer of 0-10,000, z is an integer of 1-100,000. The method of claim 1, wherein in Formula 1 x is an integer of 1 to 10,000, y is an integer of 0 to 10,000, z is an integer of 4 to 100,000, x / y is 1: 19 or more, (x + y): z is an organic electroluminescent advertising molecule, characterized in that it has a ratio of 5: 95 to 20: 80 The organic electro-adhesive molecule according to claim 1, wherein A ₁ is selected from the following compounds.

The organic electroluminescent device according to claim 1, wherein the aryl group having a heterocycle selectable by A ₁ is the following compound.

. Wherein R1 and R2 are the same or different from each other and are selected from the group consisting of hydrogen or a straight or branched chain alkyl or alkoxy group having 1 to 20 carbon atoms. The organic electroluminescent device according to claim 4, wherein R1 and R2 are the same or different from each other.

The method of claim 1, wherein Ar ₂ is: (Iii) a C6 to C60 substituted or unsubstituted arylene group; (Ii) a C2 to C60 substituted or unsubstituted heterocyclic arylene group wherein at least one hetero atom selected from the group consisting of N, S, O, P and Si is included in the aromatic ring; (Iii) a C 6 to C 60 substituted or unsubstituted arylenevinylene group; And (iv) selected from the group consisting of combinations thereof Herein, the substituent of Ar ₂ may be a linear or branched alkyl or alkoxy group having 1 to 20 carbon atoms; An aryl group which is unsubstituted or substituted with at least one substituent selected from the group consisting of a linear or branched alkyl group having 1 to 20 carbon atoms and an alkoxy group; Cyano group (-CN); And silyl groups. Organic electro-adhesive molecules, characterized in that selected from the group consisting of. According to claim 1, wherein the organic electro-adsorption molecule has an average molecular weight of 800 to 4,000,000, the molecular weight distribution of the organic electro-adhesion molecule, characterized in that 1-10. An organic electroluminescent device comprising at least one layer comprising an organic electroluminescent molecule according to any one of claims 1 to 7 between an anode and a cathode, wherein said layer is a hole transport layer or a light emitting layer. The method according to claim 8, wherein the structure of the electroluminescent device is an anode / light emitting layer / cathode, anode / hole transport layer / light emitting layer / cathode, anode / light emitting layer / electron transport layer / cathode or anode / hole transport layer / light emitting layer / electron transport layer / cathode An organic electroluminescent device characterized by.

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