KR20080104820A - Organic electroluminescent polymer containing oxadiazole group and organic electroluminescent device manufactured using the same - Google Patents

Abstract

An organic electroluminescent polymer, and organic electroluminescent device containing the polymer are provided to improve electron injection and solubility, to increase luminous efficiency by minimizing molecular interaction and to enhance color purity. An organic electroluminescent polymer is represented by the chemical formula 1, wherein A are identical or different one another and are an aryl group substituted or unsubstituted with at least one C1-C20 linear or branched alkyl or alkoxy group, an aryl group having at least one hetero atom selected from F, S, N, O, P and Si substituted or unsubstituted with at least one C1-C20 linear or branched alkyl or alkoxy group, or an aryl group having a C2-C4 hetero-ring having at least one hetero atom selected from F, S, N, O, P and Si substituted or unsubstituted with at least one C1-C20 linear or branched alkyl or alkoxy group; R is an aryl group substituted or unsubstituted with at least one C1-C20 linear or branched alkyl or alkoxy group; Ar is a substituted or unsubstituted C6-C60 aromatic compound, a substituted or unsubstituted C2-C60 hetero aromatic compound or their combination; x is an integer of 1-1,000; y is an integer of 4-10,000; and x:y is 3:97 to 20:80.

Description

Organic electroluminescent polymer containing oxadiazole group and organic electroluminescent device using same TECHNICAL FIELD

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-molecules represented by M4 of the present invention.

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

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

<Explanation of symbols for main parts of the drawings>

11 substrate 12 anode

13 hole transport layer 14 light emitting layer

15: electron transport layer 16: cathode

The present invention relates to an electroluminescent molecule containing a structural unit containing an oxadiazole group and an electroluminescence device (EL device) using the same, and more particularly, an electron pulling to facilitate the injection and transfer of electrons. Organic electroluminescent molecules containing a structural unit that functions as a dopant that emits light with high efficiency, including chain oxadiazoles and vinyl groups that improve hole injection and delivery functions, and electroluminescent devices using the same It is about.

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 responding and self-emissive, so they do not require backlighting and show 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 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 with the organic electroluminescent element which has is advanced.

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 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, since the low molecule is easy to be purified, impurities can be almost eliminated, and the light emitting property is excellent. However, there is a problem in that inkjet printing or spin coating is impossible and heat resistance is poor, thereby deteriorating or recrystallization by 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.

With respect to the polyfluorene derivatives, the prior art is as follows:

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 layers or carrier transport layers of light emitting diodes.

US Patent Nos. 6,309,763 and 6,605,373 introduce electroluminescent copolymers containing florin groups and amine groups in repeat units. According to US Pat. No. 6,309,763, such copolymers are useful as light emitting or hole transporting layers of electroluminescent devices.

On the other hand, US Patent No. 6,630,566 discloses a polymer containing 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 Electroluminescent polymers are disclosed that contain fluorene or phenylene repeat units and triarylamine units such that the transporter and cation transport materials are present 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.

Accordingly, in the present invention, as a result of extensive research in order to solve the above problems, it has excellent electron injection and transfer function and solubility, and has high luminous efficiency by minimizing intermolecular interactions, while existing polyfluorene-based (PFs An electroluminescent molecule containing a novel structural unit that significantly improves the color purity and luminous efficiency, which is a disadvantage of the present invention, and an electroluminescent device using the same have been found, and the present invention has been completed based thereon.

Accordingly, an object of the present invention is to provide an organic electroluminescent polymer which can realize blue, green, red and white light emission with high efficiency by minimizing intermolecular interactions and facilitating energy transfer. have.

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 contains a structural unit comprising an oxadiazole and a vinyl group, represented by the following formula (1):

Wherein A 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 ; Or carbon atoms 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 Aryl group having 2 to 4 heterocycles;

R is a linear or branched alkyl group having 1 to 20 carbon atoms;

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

x is an integer of 1-1,000, y is an integer of 4-10,000, and x: y preferably has a ratio of 3: 97-20: 80.

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, an electron transport layer or a light emitting layer It is done.

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

As described above, in the present invention, a blue light emitting dopant which emits light with high efficiency by including oxadiazole which is an electron pulling body that facilitates the injection and transfer of electrons and a vinyl group that improves the hole injection and transfer function in the same ratio ( An organic electroluminescent molecule containing a structural unit functioning as a dopant) and an electroluminescent device using the same.

The electroadhesive molecule containing the novel structural unit according to the present invention is represented by the following Chemical Formula 1:

[Formula 1]

Wherein A 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 ; Or carbon atoms 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 Aryl group having 2 to 4 heterocycles;

R is a linear or branched alkyl group having 1 to 20 carbon atoms;

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

x is an integer of 1-1,000, y is an integer of 4-10,000, and x: y preferably has a ratio of 3: 97-20: 80.

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, in Formula 1, A 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:

In the above formula, R1 and R2 are the same as or different from each other, hydrogen, or are selected from the group consisting of linear or branched alkyl groups and alkoxy groups having 1 to 20 carbon atoms, preferably selected from the following compounds.

In Formula 1, R is hydrogen, or is selected from the group consisting of a linear or branched alkyl group having 1 to 20 carbon atoms, preferably selected from the following compounds.

On the other hand, Ar is preferably,

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

(Ii) a C2-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 C6-C60 substituted or unsubstituted arylenevinylene group; And

(Iii) selected from the group consisting of combinations thereof

Here, Ar is a straight or branched chain 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 is a phenylene group or a fluorenyl group among the substituted or unsubstituted arylene groups of C6 ~ C60, representative examples of these compounds are as follows, and may be selected from:

(Ii) where Ar 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 is a C6 ~ C60 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 polymer obtained therefrom is 800 ~ 4,000,000, the molecular weight distribution is 1 ~ 10.

In the above-mentioned organic electroluminescent molecules according to the present invention, the bandgap of the chromophore portion having a special structure is the lowest, and thus this portion leads the light emission. In this case, an oxadiazole group, which is an electron-gripping body that facilitates the injection and transfer of electrons, is substituted at the end of the chromophore, which is a light emitting part, and a vinyl group which is easy to inject holes is located in the middle of the chromophore. The fluorinyl group is substituted to facilitate the injection and transfer of electrons and holes, as well as excellent thermal stability, oxidation stability and solubility, high glass transition temperature, minimal intermolecular interaction, and easy energy transfer. In addition, it can be applied as a blue light emitting material showing a high luminous efficiency and a host for green, red and white light emitting by suppressing the vibration mode as much as possible.

According to the present invention, the organic electroluminescent molecule is used as a material for forming a light emitting layer, an electron transport 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, transparent indium tin oxide (ITO), tin oxide (SnO 2), zinc oxide (ZnO), or the like 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 ~ 10,000Å.

According to the present invention, a material for forming an electron transport layer may be used for the electron transport layer 15, or the compound represented by Chemical Formula 1 may be formed by vacuum deposition, sputtering, spin coating, or inkjet printing.

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 introduces a large substituent fluorenyl group into a special structural unit, thereby randomizing the arrangement between the main chain and the substituent by the substituent, and the intermolecular excimer by the substituent is suppressed as much as possible. The property is expressed to inhibit aggregation and / or excimer formation. In addition, not only the intramolecular or intermolecular energy transfer from the short wavelength substituent or the chromophore of the main chain to the chromophore having the structural unit according to the present invention is possible, but also the rotation and vibration mode are suppressed by the substituted large fluorenyl group, thereby slandering. The yarn attenuation is greatly reduced to have excellent thermal stability, light stability, solubility, film formability and high quantum efficiency, and have a great advantage as a blue light emitting unit having high color purity with high efficiency. 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 mentioned as M1 to M4 below 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.

Production Example  1: (9- (9,9- Dihexylfluorene 2-yl) -2,7- Dibromofluorene -9-ol) (compound (1))

3.3 g (137 mmol) of Mg was added to a 500 mL three neck flask at room temperature. 47.1 g (114 mmol) of 9,9-dihexyl-2-bromofluorene was dissolved in 200 mL of THF and slowly added dropwise to the Grignard reagent. Made. 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 was poured into water, extracted with diethyl ether and the solvent was evaporated with a rotary evaporator. 45 g (67 mmol, 73%) of 9- (9,9-dihexylfluoren-2-yl) -2,7-dibromofluorene-9-ol (compound ( 1)) was obtained.

Production Example  2: (1,2- Di (2-methyl) butyloxybenzene Synthesis of (Compound (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 53 g of potassium tert-butoxide (t-BuOK). 473 mmol) equivalents were added slowly and reacted 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 (Compound (2)) was obtained.

Preparation Example 3 Synthesis of Monomer M1

52.5 g (78 mmol) of Compound (1) obtained in Preparation Example 1 and 23.3 g (93 mmol) of Compound (2) obtained in Preparation Example 2 were dissolved in 1000 mL of dichloromethane in a 2 L round flask at room temperature. The mixture was lowered to 0 ° C. and slowly injected with a solution of 7.5 g (78 mmol) of methane sulfonic acid in 100 mL of dichloromethane while stirring, followed by stirring for 2 hours. The reaction was poured into water, extracted with diethyl ether and the solvent removed by 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) was obtained.

Production Example  4: 9- (9,9- Dihexylfluorene -2-yl) -9- (3,4- Di (2-methyl) butyloxyphenyl ) Fluorene -2,7- Of diboric acid (compound (3))  synthesis

58.8 g (65 mmol) of M1 was added to a 250 mL round flask at room temperature, dissolved in 60 mL of THF, cooled to -70 ° C, and then slowly added 2 equivalents of 2.5Mn-butyllithium to -70 to -40 for 2 hours. After reacting at a low temperature of 4 ° C., 4 equivalents of triethyl borate were 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 and dried to obtain 9,9-di (9). 41.2 g (76%), 9-dihexyl) fluoren-2-yl-9- (3,4-di (2-methyl) butyloxyphenyl) fluorene-2,7-diboric acid (compound (3)) )

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, and a Deanstark apparatus was installed. The mixture was refluxed for 24 hours 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- 50.2 g (57 mmol, 87%) of 2,7-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 in a 2 L round flask at room temperature, and then the temperature was lowered to 0 ° C. The solution was dissolved slowly in 100 mL of dichloromethane and stirred for 2 hours. The reaction was poured into water and extracted with diethyl ether, then the solvent was removed by 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 Synthesis of Compound (4)

20 g (133 mmol) of 4-bromobenzoic hydrazide was added to a 500 mL three neck flask, and 20 mL of pyridine and 100 mL of dichloromethane were added and stirred under a nitrogen stream. 29.2 g (133 mmol) of 4-bromo benzoyl chloride was dissolved in 200 mL of dichloromethane and slowly added dropwise thereto, followed by stirring for 3 hours.

Dichloromethane is removed using a rotary evaporator to generate solids. The solids are washed with boiling water for 6 times and then washed twice with a solvent mixture of water: methanol (3: 1) and dried in a vacuum oven to give 19.9. g (60 mmol, 45%) was obtained.

Production Example  8: Synthesis of Compound (5)

15 g (45 mmol) of Compound (4) obtained in Preparation Example 7 and 100 mL of thionyl chloride were added to a 250 mL 1-neck round flask, and the mixture was refluxed for 12 hours. After thionyl chloride was distilled off, the mixture was washed three times with ethanol and dried in a vacuum oven to obtain 10.6 g (34 mmol, 75%) of Compound (5).

Production Example  9: Synthesis of Compound (6)

10 g (32 mmol) of Compound (5) was dissolved in 200 mL of anhydrous benzene in a 500 mL three neck flask, and the temperature was raised to reflux under a nitrogen stream. 5.65 g (32 mmol) of N-bromosuccinimide and 0.2 g (1.4 mmol) of benzoyl peroxide were slowly injected. After refluxing for 3 hours, the reaction was cooled to room temperature, benzene was removed by a rotary evaporator, and separated by column chromatography to obtain 7.94 g (20 mmol, 63%) of compound (6).

Production Example  10: Synthesis of Compound (7)

7 g (17.8 mmol) of compound (6) and 20 mL of triethyl phosphite were added to a 100 mL 1-neck flask, and stirred at 110 ° C. for 12 hours, followed by vacuum distillation to remove triethyl phosphite, After washing four times with 100 mL of anhydrous normal hexane, and dried in a vacuum oven to give 6.9 g (15.3 mmol, 86%) of compound (7).

Production Example  11: Synthesis of Compound (8)

10 g (11.3 mmol) of monomer M2 and 4.6 g (24.9 mmol) of 4-bromo benzaldehyde were added to a 100 mL three-necked round flask and dissolved by adding 40 mL of THF. Then, 20 mL of 2M-K2CO3 was added and nitrogen bubble was added for 30 minutes. After bubbling, 0.15 g (0.13 mmol) of tetrakis (triphenylphosphine) palladium (0) was injected and stirred under reflux for 12 hours. After the temperature was lowered to room temperature, the reaction was poured into water, extracted with dichloromethane, and the solvent was removed by a rotary evaporator. Dichloromethane and normal hexane (1:10) were used for column chromatography to give 8.6 g (9.3 mmol, 82%) of compound (8).

Production Example  12: monomer M4 Synthesis of

5 g (11.9 mmol) of compound (7) and 5 g (5.4 mmol) of compound (8) were added to a 250 mL three-necked round flask, and dissolved by adding 100 mL of anhydrous THF, followed by potassium tert-butoxide (t-BuOK). 1.7 g (15 mmol) was added slowly and stirred for 3 h. The solvent was removed by rotary evaporator, extracted with dichloromethane, and then the solvent was removed by rotary evaporator. Dichloromethane and normal hexane (3:10) were used for column chromatography to obtain 3.5 g (2.3 mmol, 43%) of monomer M4.

Example  1: Synthesis of Electromolecules

Suzuki coupling reaction known as carbon-carbon coupling reaction using monomers M1, M2, M3, and M4 prepared by the methods of Preparation Examples 1 to 12 (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 weight of the polymer 1 using the monomer having the new structural characteristics was 430,000 (PDI = 2.7), respectively, showing a high degree of polymerization, which 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%) Molecular Weight (Mw) Molecular Weight (Mn) PDI Example 1 Polymer 1 20 50 20 10 430,000 162,000 2.7

Example  2: Manufacture 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 polymer for an electroluminescent device manufactured from Example 1 Spin coating to form a light emitting layer having a thickness of 700 ~ 1000Å. 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) Highest brightness (cd / m ² ) Color coordinates (x, y) Example 2 Polymer 1 3.2 3.88 15,570 (0.175, 0.191)

The electroluminescent polymer 1 prepared from Example 1 is an electroluminescent molecule that improves luminance and electroluminescence efficiency by introducing M4 having a special structural unit developed in the present invention into a basic structure composed of M1, M2 and M3. In the case of the electroluminescent device manufactured using the same, as shown in Table 2, 4 and 5, in the case of the organic electroluminescent device using the polymer 1 using 10 mol% of monomer M4 having a special structure developed in the present invention While the low starting voltage was 3.2 V, the highest efficiency was found to be 3.88 cd / A at 1330 cd / m ² , and the color coordinate at 450 cd / m ² was blue with x, y = (0.175, 0.191). It emits light in the region, and shows excellent electroluminescence properties such as the maximum luminance of 15,570 cd / m ² .

The high luminous efficiency and luminance in the organic electroluminescent device using the polymer 1 is due to the excellent injection and transfer of electrons and holes of the monomer of the polymer M4 according to the present invention as a good chromophore and the substitution of fluorenyl group having a large substituent It is considered to be a phenomenon due to the complete inhibition of intermolecular interactions and excimers.

These results indicate that the polymers developed in the present invention have excellent electroluminescence properties such as luminance, color purity, and efficiency, which are commercialization aspects.

As described above, the electro-adhesion molecules incorporating the monomer M4 having a special structural unit having excellent injection / transferability of electrons and holes developed in the present invention have a markedly improved luminous efficiency and luminance, and excellent thermal stability. In addition, it is possible to minimize the intermolecular interactions by the bulky substituents, so it has high luminous efficiency and excellent solubility so that a thin thin film is made well. When used as a host material such as red, excellent light emission characteristics can be exhibited.

The organic electro-adhesive molecule according to the present invention is a light emitting polymer having properties of excellent thermal stability, light stability, solubility, film formability, excellent electron injection / transfer quality and hole injection / transfer quality, excellent color purity and high luminous efficiency. A fluorenyl group with a large substituent in the center of the structural unit minimizes the overlap between chromophores, thereby minimizing intermolecular excimers and aggregation, and intermolecular or intermolecular energy transfer. Since the organic electroluminescent molecule of the present invention is easy to exhibit high light emission characteristics such as high luminous efficiency.

Claims (6)

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

Wherein A 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, identically or differently; 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 ; Or carbon atoms 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 Aryl group having 2 to 4 heterocycles; R 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; Ar is selected from the group consisting of C6-C60 substituted or unsubstituted aromatic compounds, C2-C60 substituted or unsubstituted heteroaromatic compounds, and combinations thereof; x is an integer of 1-1,000, y is an integer of 4-10,000, and x: y has a ratio of 3: 97-20: 80. The organic electroadhesive molecule according to claim 1, wherein A is selected from the following compounds.

The method of claim 1, wherein Ar is: (Iii) a C6-C60 substituted or unsubstituted arylene group; (Ii) a C2-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 C6-C60 substituted or unsubstituted arylenevinylene group; And (iv) selected from the group consisting of combinations thereof Here, the substituent of Ar 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 is a weight-average molecular weight is an integer of 800 ~ 4,000,000, the molecular weight distribution is an organic electro-adhesion molecule, characterized in that 1 to 10. An organic electroluminescent device comprising at least one layer between an anode and a cathode comprising the organic electroluminescent molecules according to any one of claims 1 to 4, wherein said layer is an electron transport layer, a hole transport layer or a light emitting layer. device. The organic electroluminescent device according to claim 5, wherein the structure of the electroluminescent device is an anode / light emitting layer / cathode, an anode / hole transporting layer / light emitting layer / cathode, or an anode / hole transporting layer / light emitting layer / electron transporting layer / cathode.

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