KR20040026542A - Novel arylphosphine compounds and organic electroluminescent devices - Google Patents

Abstract

PURPOSE: An arylphosphine compound and an organic electroluminescent(EL) device using the same are provided, thereby cheaply manufacturing the organic electroluminescent(EL) device having improved luminescence efficiency at low electric field and improved heat stability. CONSTITUTION: An arylphosphine compound with a diarylphosphino group represented by the formula(1) is provided, wherein X is C6 to C21 optionally substituted arylene; Ar is C6 to C21 optionally substituted aryl; and the substituent of arylene or aryl is selected from halogen, nitro, cyano, C1 to C6 alkyl, C1 to C6 halogenated alkyl and C1 to C6 alkoxy. An organic electroluminescent(EL) device has the arylphosphine compound with a diarylphosphino group of the formula(1). A process for preparing the arylphosphine compound with a diarylphosphino group of the formula(1) comprises reacting diarylphosphino benzaldehyde compound with a diphosphate compound or a diphosphonium halide compound.

Description

Novel arylphosphine compounds and organic electroluminescent devices employing the same

The present invention relates to an aryl phosphine compound and an organic light emitting device (hereinafter referred to as an organic EL device) including the same, and more particularly, an aryl phosphine compound having a new molecular structure that can be usefully used as a light emitting material, and The organic EL device and the like employing the same.

In recent years, organic electroluminescent element attracts attention as a flat display element of high brightness. The EL element has a structure in which a light emitting layer is inserted between two electrodes. The EL element can function as a display by recombining and emitting light from holes injected from the anode and electrons injected from the cathode in the light emitting layer.

In the past, inorganic compounds have been mainly used as EL materials. However, in order to apply them to EL devices, a high voltage must be applied. Therefore, recently, an organic EL device capable of lowering a driving voltage using an organic compound has been developed, and an organic light emitting material has been developed accordingly.

As an example of an organic light emitting material for an organic EL device, an organometallic compound such as AlQ3 represented by Chemical Formula i (CW, Tang Appl. Phys. Lett, 51 (12), 1987), and bis styryl represented by Chemical Formula ii Arylene derivatives (US Pat. No. 5,516,577), polyaromatic compounds such as anthracene derivatives represented by the following formula (iii) (Korean Patent Publication No. 2002-0011686), and arylamine derivatives represented by the following formula (iv) (Korean Patent Publication No. 1999 -0062697).

[Formula i]

[Formula ii]

[Formula iii]

Here, R ₁ and R ₂ represent carbazole, diphenylamine, or methylphenylene.

[Formula iv]

However, such organic light emitting materials for organic EL devices are still insufficient in terms of light emission luminance, heat resistance, and the like, and thus there is still a great need for development of organic compounds for organic EL devices having excellent heat resistance and luminance characteristics.

Accordingly, an object of the present invention is to provide an arylphosphine-based compound having a novel molecular structure that can be usefully used as an organic light emitting material for an organic EL device, a light emitting material including the same, and an organic EL device including the same.

Another object of the present invention is to provide a method for preparing the arylphosphine-based compound.

1 shows a cross-sectional structure of an organic EL device according to an aspect of the present invention.

2 to 4 show fluorescence spectra of compounds 2, 3 and 4 according to the present invention, respectively.

5 shows a photoluminescence spectrum of 2,6-bis [2 (4-diphenylphosphinophenyl) vinyl] naphthalene represented by the formula (4).

6 shows a current-voltage (I-V) characteristic curve of the organic EL device of Example 5. FIG.

7 shows the luminance-voltage (L-V) characteristic curve of the organic EL device of Example 5. FIG.

FIG. 8 shows the efficiency-voltage (Eff (cd / A) -V) characteristic curve of the organic EL device of Example 5. FIG.

<Explanation of symbols for the main parts of the drawings>

1 transparent substrate 3 cathode 5 anode

7 light emitting layer 9 hole transport layer 50 organic EL device

The present invention to achieve the above object.

It provides an arylphosphine-based compound having a diaryl phosphino group represented by the general formula (1):

[Formula 1]

Here, X represents a substituted or unsubstituted arylene group of C6 to C21, Ar represents a substituted or unsubstituted aryl group of C6 to C21, respectively, the substituent when the arylene group or aryl group is substituted is a halogen group, a nitro group , A cyano group, a C1 to C6 alkyl group, a C1 to C6 halogenated alkyl group and a C1 to C6 alkoxy group.

In the arylphosphine compound of the present invention, the arylene group X is preferably a phenylene group, a biphenylene group or a naphthylene group.

In order to achieve the above object, the present invention also provides a light emitting material containing an aryl phosphine-based compound having the diaryl phosphino group.

In order to achieve the above object, the present invention also provides an organic EL device containing an arylphosphine-based compound having the diaryl phosphino group.

In order to achieve the above another object, the present invention,

Provided is a method for preparing an arylphosphine-based compound having a diarylphosphino group, wherein the diarylphosphino benzaldehyde compound is reacted with a diphosphonate compound or a diphosphonium halide compound.

Hereinafter, the arylphosphine type compound which has the diaryl phosphino group of the new structure which concerns on this invention is demonstrated.

As described above, the arylphosphine-based compound according to the present invention is characterized by being an arylphosphine-based compound having a diarylphosphino group represented by the following Chemical Formula 1.

[Formula 1]

Here, X represents a substituted or unsubstituted arylene group of C6 to C21, Ar represents a substituted or unsubstituted aryl group of C6 to C21, respectively, the substituent when the arylene group or the aryl group is substituted is a halogen group, a nitro group , A cyano group, a C1 to C6 alkyl group, a C1 to C6 halogenated alkyl group and a C1 to C6 alkoxy group.

Useful arylene group X includes 1,4-phenylene group, 1,3-phenylene group, or 1,2-phenylene group; 2,6-naphthylene group or 1,5-naphthylene group; 4,4'-biphenylene group, 2,2'-biphenylene group, and the like, but is not limited thereto. The phenylene group, naphthylene group, biphenylene group may be substituted with a halogen group, a nitro group, a cyano group, a C1 to C6 alkyl group, a C1 to C6 halogenated alkyl group, a C1 to C6 alkoxy group, or the like. Here, "naphthylene group" means an arylene group connected to the vinyl group of the formula (1) at the position indicated by the above two numbers of the chemical structure of "naphthalene".

Useful aryl groups Ar include phenyl group, α-naphthyl group, β-naphthyl group, 1-anthracenyl group, 2-anthracenyl group, 9-anthracenyl group, 1-phenanthrenyl group, 2-phenanthrenyl group, 3-phenan A threnyl group, 4-phenanthrenyl group, 9-phenanthrenyl group, 1-fluorenyl group, 2-fluorenyl group, 3-fluorenyl group, 4-fluorenyl group, 9-fluorenyl group, etc. It is not limited to this. These phenyl groups, naphthyl groups, anthracenyl groups, phenanthrenyl groups, and fluorenyl groups are also halogen, nitro, cyano, alkyl groups of C1 to C6, halogenated alkyl groups of C1 to C6, and alkoxy groups of C1 to C6. It may be substituted with at least one selected.

Specific examples of the arylphosphine-based compound having a diaryl phosphino group according to the present invention represented by the formula (1) include, but are not limited to, the compounds represented by the following formulas (2) to (5).

[Formula 2]

Figure 2 shows the fluorescence spectrum (PL) of the compound represented by the formula (2). This fluorescence spectrum was taken after the compound of formula 2 was dissolved in chloroform. It can be seen that the compound represented by Chemical Formula 2 has a maximum absorbance (PLmax) at 369 nm and a blue light-emitting material having another maximum peak at 442 nm.

[Formula 3]

Figure 3 shows the fluorescence spectrum of the compound represented by the formula (3). This fluorescence spectrum was taken after the compound of formula 3 was dissolved in chloroform. From this, the compound represented by Chemical Formula 3 may have a maximum absorbance (PLmax) at 365 nm and a blue light-emitting material having another maximum peak at 418 nm.

[Formula 4]

Figure 4 shows the fluorescence spectrum of the compound represented by the formula (4). This fluorescence spectrum was taken after the compound of formula 4 was dissolved in chloroform. It can be seen that the compound represented by Formula 4 has a maximum absorbance (PLmax) at 432 nm and is a blue light-emitting material having another maximum peak at 369 nm.

[Formula 5]

5 shows a photoluminescence spectrum of 2,6-bis [2 (4-diphenylphosphinophenyl) vinyl] naphthalene represented by the formula (4). This fluorescence spectrum was taken after the compound of formula 5 was dissolved in chloroform. From this it can be seen that the compound represented by Formula 5 is a blue light-emitting material having a maximum absorbance (PLmax) at 483 nm.

The arylphosphine-based compound of the formula (1) according to the present invention is the first as long as the light emitting material having a diaryl phosphino group as a functional material known by the present inventors. This compound has an excellent advantage that it can efficiently emit light even in a low electric field and can be easily formed into a uniform amorphous film even by vacuum deposition. Therefore, by using this compound, an organic EL device can be easily produced at low cost. In addition, since the arylphosphine-based compound of the present invention has a high melting point and decomposition temperature, the organic EL device manufactured by using the arylphosphine-based compound may exhibit excellent durability because it is thermally stable.

The arylphosphine-based compound of Formula 1 according to the present invention can emit an organic EL device having a different emission color by photoluminescence of blue and the introduction of another light emitting material such as blue, green, or red light emitting material.

Next, a method for preparing the arylphosphine compound of Formula 1 according to the present invention will be described.

The arylphosphine-based compound according to the general formula (1) of the present invention is (1) a method of reacting a diarylphosphino benzaldehyde compound and a diphosphonate compound having an arylene group or (2) a diarylphosphino benzaldehyde compound and an arylene group It can obtain by the method of reacting the diphosphonium halide compound which has a.

The reaction of (1) above is carried out for 3 to 10 hours in the presence of a base catalyst such as t-BuOK, NaH, BuLi in THF, toluene, or a mixed solvent thereof for the phosphate compound having a arylphosphino benzaldehyde compound and an arylene group. It is progressed by the method of reflux at room temperature or heating.

In the reaction of (2), the diaryl phosphino benzaldehyde compound and the diphosphonium halide compound having an arylene group are replaced by methylene chloride, 1,2-dichloroethane, chloroform, methanol, ethanol, carbon tetrachloride, DMSO or a mixed solvent thereof. In the presence of a basic catalyst such as NaOEt, NaH, NaOH in the process by heating to reflux for about 3 to 10 hours. At this time, the reaction temperature is preferably adjusted to 50 ℃. If the reaction temperature is less than 50 ℃ there is a problem that the yield is lowered.

When the reaction of (1) or (2) is complete, the reaction product is precipitated by addition to water, filtered, and then recrystallized or column purified using a solvent such as methylene chloride, chloroform, ethanol, or the like. An aryl phosphine type compound which has a group as a functional group can be obtained. This aryl phosphine compound mainly has yellow crystals, usually has a high melting point (mp) of 180 ° C. or higher and in some cases of about 210 ° C. or higher, and has a decomposition temperature of about 400 ° C. The thermal stability is excellent.

The diarylphosphino benzaldehyde compound is obtained by reacting a diaryl halogenophenyl phosphine with dimethylformamide with a reactive material obtained by reacting diaryl halogenophenyl phosphine with magnesium or butyllithium in hexane, THF, ether or a mixed solvent thereof under an inert air stream. At this time, the reaction temperature should be maintained at a low temperature below 0 ℃. If the reaction temperature exceeds 0 ℃ there is a problem that the yield is lowered.

The diphosphonium halide compound having an arylene group can be obtained by heating and refluxing a dihalide compound having an arylene group in a solvent such as DMF and toluene under an inert air stream with triaryl phosphine. Other detailed reaction conditions of the arylphosphine-based compound according to the present invention will be apparent with reference to the following synthesis examples.

Meanwhile, the EL device using the arylphosphine-based compound according to Formula 1 according to the present invention can be realized in various structures. Basically, as shown in FIG. 1, the organic EL device 50 of the present invention includes a light emitting layer including an arylphosphine-based compound according to Chemical Formula 1 of the present invention between the cathode 3 and the anode 5. 7) and the hole transport layer 9 is inserted. Optionally, another light emitting material may be introduced into the light emitting layer 7 including the arylphosphine-based compound of Formula 1 to emit light having different wavelengths and to improve the light emitting efficiency of the layer. In addition to the light emitting layer 7 and the hole transport layer 9, an electron injection layer, a hole injection layer, and an electron transport layer may be separately stacked to improve the luminous efficiency of the organic EL device.

The organic EL device having the above structure is preferably supported by a transparent substrate (1 in FIG. 1). The material of the transparent substrate is not particularly limited as long as it has good mechanical strength, thermal stability and transparency. For example, glass, a transparent plastic film, etc. can be used.

As the anode material of the organic EL device of the present invention, a metal, an alloy, an electrically conductive compound having a work function of 4 eV or more, or a mixture thereof can be used. Specifically, transparent conductive materials such as Au, CuI, ITO (indium tin oxide), SnO ₂ and ZnO are mentioned.

As the negative electrode material of the organic EL device of the present invention, a metal, an alloy, an electrically conductive compound or a mixture thereof having a work function of less than 4 eV can be used. Specific examples include calcium, magnesium, lithium, aluminum, magnesium alloys, lithium alloys, and aluminum alloys. In addition, aluminum / lithium, magnesium / silver or magnesium / indium or the like may also be used.

In order to increase the luminous efficiency of the organic EL device, at least one electrode should preferably have a light transmittance of 10% or more. The sheet resistance of the electrode is preferably several hundreds of mm 3 / mm or less. The thickness of the electrode is 10 nm to 1 탆, preferably 10 to 400 nm. Such an electrode may be manufactured by forming the above electrode material into a thin film through vapor deposition or sputtering such as chemical vapor deposition (CVD), physical vapor deposition (PVD), or the like.

The hole transport material and the hole injection material can be arbitrarily selected from materials commonly used as hole charge transport materials in photoconductive materials and known materials used in the hole transport layer or the hole injection layer of organic EL devices. For example, N, N'-diphenyl-N, N'-di (3-methylphenyl) -4,4'-diaminobiphenyl (hereinafter referred to as TPD), aromatic tertiary amine in the main chain or side chain Polymer having, 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane, N, N'-diphenyl-N, N'-dinaphthyl-4,4'-diaminobiphenyl, 4 Triarylamine derivatives such as 4 ', 4'-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine; Carbazole derivatives such as N-phenylcarbazole and polyvinylcarbazole; Phthalocyanine derivatives such as metal phthalocyanine and copper phthalocyanine; Advanced materials Vol. Starburst amine derivatives described in 6, page 677 (1994); Stilbene derivatives such as those described in Proceedings (II) of the 72th annual spring convention of The Chemical Society of Japan; And polysilanes.

In the organic EL device of the present invention, the hole injection layer and / or the hole transport layer are formed of a single layer containing one or more kinds of the above-described compounds, or stacked into a plurality of layers containing different kinds of compounds. Can be configured.

There are no particular limitations on the electron injection material and electron transport material of the organic EL device of the present invention, and materials commonly used as charge transport materials among photoconductive materials and known materials used in the electron transport layer or the electron injection layer of the organic EL device. Can be used arbitrarily selected from.

Specific examples of such electron transfer compounds include diphenylquinone derivatives such as those described in Denshi-shashin Gakkai-shi, 30, 3 (1991); J. Appl. Perylene derivatives as described in Phys., 27, 296 (1988); Jpn. J. Appl. Phys., 27, L713 (1988) or Appl. Phys. Oxadiazole derivatives such as those described in Lett., 55, 1489 (1989); Thiophene derivatives such as those described in JP-A-4-212286; Jpn. J. Appl. Triazole derivatives as described in Phys., 32, L917 (1993); Thiadiazole derivatives as described in The 43th Proceedings of The Society of Polymer Science, Japan, (III) Pla007; Metal complexes of auxin derivatives such as those described in the Technical Research Report of Denshi Jyoho Tsushin Gakkai, 92 (311), 43 (1992); Jpn. J. Appl. Polymers of quinoxaline derivatives as described in Phys., 33, L250 (1994); And phenanthroline derivatives as described in The 43th Proceedings of Kobunshi Toronkai, 14J07.

Other light emitting materials used in the organic EL device of the present invention in addition to the arylphosphine-based compound represented by Formula 1 include known light emitting materials, for example, photoluminescent fluorescent materials, fluorescent brighteners, laser dyes, organic scintillators, and fluorescence analysis. Reagents can be used. Specific examples include polyaromatic compounds such as anthracene, phenanthrene, pyrene, chrysene, perylene, coronene, rubrene and quinacridone; Oligophenylene compounds such as quiterphenyl; 1,4-bis (2-methylstyryl) benzene, 1,4-bis (4-methylstyryl) benzene, 1,4-bis (4-methyl5-phenyl-2-oxazolyl) benzene, 1, 4-bis (5-phenyl-2-oxazolyl) benzene, 2,5-bis (5-t-butyl-2-benzoxazolyl) thiophene, 1,4-diphenyl-1,3-butadiene, 1 Scintillators for liquid scintillation such as, 6-diphenyl-1,3,5-hexatriene, 1,1,4,4-tetraphenyl-1,3-butadiene; Metal complexes of the auxin derivatives described in Japanese Patent Application Laid-Open No. 63-264692; Coumarin pigments; Dicyano methylene pyran pigment; Dicyano methylenethiopyran pigments; Polymethine pigments; Oxobenzanthracene pigment; Xanthene pigments; Carbostyryl pigments; Perylene pigments; Oxazine compounds described in German Patent No. 2534713; stilbene derivatives described in the Proceedings of the 40th Joint Lecture of Applied Physics, 1146 (1993); Spiro compounds described in JP-A-7-278537; The oxadiazole compound of Unexamined-Japanese-Patent No. 4-393891, etc. are mentioned.

Each layer constituting the organic EL device of the present invention can be formed into a thin film through a known method such as vapor deposition, spin coating or casting, or can be produced using a material used in each layer. There is no particular limitation on the film thickness of each layer, and may be appropriately selected depending on the properties of the material, but can usually be determined in the range of 2nm to 5000nm.

Since the arylphosphine-based compound represented by Chemical Formula 1 according to the present invention can be formed by a deposition method, the thin film forming process is simple, and there is an advantage that it can be easily obtained as a homogeneous thin film having little pin holes. . When the arylphosphine-based compound represented by Chemical Formula 1 is formed into a thin film by using a deposition method, preferred deposition conditions are usually 50 to 400 ° C depending on the type of the arylphosphine-based compound and the crystal structure and association structure of the desired molecular accumulation film. Boat heating temperature of 10 ^-7 to 10 ^-4 torr, a deposition rate of 0.01 to 50 nm / sec, a substrate temperature of -150 to 50 DEG C, and a film thickness of 10 to 200 nm are preferred.

A method of manufacturing an organic EL device using the arylphosphine-based compound represented by Formula 1 of the present invention will be described with reference to the organic EL device formed of the above-described anode / hole transport layer / arylphosphine compound layer / cathode. First, a cathode is formed by depositing a thin film containing a cathode material having a thickness of 1 μm or less, preferably 10 to 200 nm, on a transparent substrate such as a glass substrate. Subsequently, a hole transport layer is formed on the cathode layer using a hole transport material. Subsequently, an emission layer is formed to cover the hole transport layer with a thin film of the arylphosphine compound represented by the formula (1). Finally, the organic EL device is obtained by coating the light emitting layer with a thin film containing an anode material with a film thickness of 1 탆 or less to form an anode.

When a DC voltage is applied to the organic EL device obtained by using the positive electrode as the positive electrode and the negative electrode as the negative electrode, light emission can be observed through a transparent or opaque electrode (either positive or negative electrode or both electrodes). In addition, the organic EL element emits light even when applying an AC voltage. In this case, the applied AC voltage may have any waveform.

Hereinafter, the present invention will be described in more detail with reference to synthesis examples and examples. The following Synthesis Examples and Examples are merely to illustrate the present invention by only illustrating the aryl phosphine-based compound and the method for producing an organic EL device of the present invention, and the present invention is not limited thereto. .

Synthesis Example 1 Synthesis of 4-diphenylphosphino benzaldehyde

This synthesis example is for explaining the synthesis of 4-diphenyl phosphino benzaldehyde according to the following Scheme 1. After replacing the inside of a 250 mL three-necked flask equipped with a reflux condenser with argon, 31.3 mL of n-butyllithium (1.6M hexane solution) was added to the flask and cooled to -60 ° C or lower. Subsequently, 50 ml of THF solution, in which 11.8 g of p-dibromobenzene was dissolved, was slowly added to the flask while stirring the hexane solution. Then, 11.0 g of chlorodiphenylphosphine was further added, followed by stirring for about 1 hour, followed by 4-broken. Mophenyldiphenylphosphine was obtained. 31.3 mL of n-butyllithium (1.6M hexane solution) was added to the hexane / THF mixed solution of 4-bromophenyldiphenylphosphine thus produced under argon atmosphere at a temperature below -60 ° C, and then stirred for 1 hour. Continued. 3.65 g of DMF was added thereto, and stirring was continued for 1 hour, and then water was added to terminate the reaction. Thus obtained 4-diphenyl phosphino benzaldehyde was extracted from the mixed solution using diethyl ether as an extraction solvent, followed by column purification with a hexane / ethyl acetate mixed solution to obtain 6.5 g of pure 4-diphenyl phosphino benzaldehyde (yield 45). %). The NMR spectroscopic data of the obtained 4-diphenyl phosphino benzaldehyde was as follows.

NMR- ¹ H (400 MHz, CDCl 3; ppm): δ = 7.33-7.39 (m, 10H), 7.40-7.42 (q, 2H),

7.79-7.81 (q, 2H), 10.00 (s, 1H, -CHO).

Scheme 1

Synthesis Example 2 Synthesis of Benzene Diphosphonate Compound

This synthesis example is for demonstrating the synthesis | combination of a benzene diphosphonate compound according to Reaction Scheme 2 below. After replacing the inside of a 100 ml three-necked flask equipped with a reflux condenser with argon, the flask was heated with stirring 10.5 g of 1,4-bis (bromomethyl) benzene and 13 g of triethyl phosphite for 4 hours. It was refluxed. Excess triethyl phosphite and byproduct ethyl bromide were then removed by distillation under reduced pressure. The residue was cooled to give 10.43 g of white diphosphonate compound crystals (yield 90%).

Scheme 2

Example 1 Synthesis of 1,4-bis [2 (4-diphenylphosphinophenyl) vinyl] benzene

This example is to explain the synthesis of 1,4-bis [2 (4-diphenylphosphinophenyl) vinyl] benzene in accordance with Scheme 3 below. After replacing the inside of a 100 ml three-necked flask equipped with a reflux condenser with argon, 2.9 g of 4-diphenylphosphinobenzaldehyde and 1.86 g of the diphosphonate compound obtained in Synthesis Example 2 were added to the flask, and THF 30 ml. After dissolving, 1.2 g of t-BuOK was added thereto and stirred for 20 hours while refluxing. The resultant was then added to excess water to precipitate the product. The precipitate was filtered and recrystallized with methylene chloride or column purified to obtain 1.2 g of yellow crystals (yield: 18.5%). The melting point (m.p) of the obtained crystal was 185.7 ° C., the decomposition temperature was 396 ° C., and NMR spectroscopic data were as follows.

NMR- ¹ H (400 MHz, CDCl 3; ppm): δ = 7.10-7.11 (d, 4H), 7.27-7.31 (m, 4H),

7.32-7.36 (m, 20 H), 7.46-7.52 (m, 8 H).

NMR- ³¹ P (CDCl 3; ppm): δ = 30.27.

Photoluminescence (chloroform): 442 nm (exitation max .: 369 nm; see FIG. 2).

Mass spectrum; m / e = 650.76 (M &lt; + &gt;).

Scheme 3

Synthesis Example 3 Synthesis of Naphthalene Diphosphonate Compound

This synthesis example is for demonstrating the synthesis | combination of a naphthalene type diphosphonate compound according to Reaction Scheme 4 below. The synthesis method was the same as in Synthesis Example 2 except that 12.5 g of 2,6-bisbromomethyl naphthalene was used instead of 10.5 g of 1.4-dibromomethyl benzene (yield: 92%).

Scheme 4

Example 2 Synthesis of 2,6-bis [2 (4-diphenylphosphinophenyl) vinyl] naphthalene

This example is to explain the synthesis of 2,6-bis [2 (4-diphenylphosphinophenyl) vinyl] naphthalene according to Scheme 5 below. Except that 1.06 g of the naphthalene diphosphenoate compound obtained in Synthesis Example 3 was reacted with 1.45 g of diphenyl phosphino benzaldehyde, 2,6-bis [2 (4) -Diphenylphosphinophenyl) vinyl] naphthalene crystals 0.5g were obtained (yield: 14.3%). The melting point (m.p) of the obtained crystal was 222.4 ° C, the decomposition temperature was 416 ° C, and NMR spectroscopy data were as follows.

NMR- ¹ H (400 MHz, CDCl 3; ppm): δ = 7.22-7.26 (d, 4H), 7.29-7.32 (m, 4H),

7.33-7.36 (m, 20H), 7.51-7.53 (q, 4H), 7.70-7.72 (q, 2H), 7.78-7.81 (q, 4H).

NMR- ³¹ P (CDCl 3; ppm): δ = 29.57.

Photoluminescence (chloroform): 436 nm (exitation max .: 368 nm; see FIG. 3).

Mass spectrum: m / e = 700.78 (M &lt; + &gt;).

Scheme 5

Synthesis Example 4 Synthesis of Phosphonium Halide Compound

This synthesis example is for explaining the synthesis of the phosphonium halide compound according to Scheme 6 below. After replacing the inside of a 100 ml three-necked flask equipped with a reflux condenser with argon, 3.4 g of 4,4'-bisbromomethyl biphenyl and 5.42 g of triphenylphosphine were added to the flask, and 20 ml of DMF was added. After dissolving, the mixture was heated to reflux with stirring for 3 to 4 hours in an argon atmosphere. Subsequently, the flask was cooled to room temperature, and the resulting solid was filtered and recrystallized with methanol to obtain 5.1 g of white diphosphonium dihalide compound crystals (yield: 57.8%).

Scheme 6

Example 3: Synthesis of 4,4'-bis [2 (4-diphenylphosphinophenyl) vinyl] biphenyl

This example is intended to illustrate the synthesis of 4,4'-bis [2 (4-diphenylphosphinophenyl) vinyl] biphenyl according to Scheme 7 below. After replacing the inside of a 100 ml three-necked flask equipped with a reflux condenser with argon, 1.73 g of the diphosphonium dihalide obtained by Synthesis Example 4 and 4-diphenylphosphino obtained by Synthesis Example 1 were added to the flask. 1.16 g of benzaldehyde was added, dissolved in 13.5 ml of anhydrous chloroform and 40 ml of anhydrous ethanol, and 20 ml of NaOEt 1.0M solution was added thereto, and the mixture was heated and refluxed under an argon atmosphere for 4 hours. The resultant was then cooled to room temperature and precipitated by addition to excess water. The resulting solid was filtered and recrystallized with methylene chloride or column purified to give 0.45 g of yellow crystals (yield: 24.8%). The melting point (m.p) of the obtained crystal was 212.3 占 폚, the decomposition temperature was 404 占 폚, and NMR spectroscopic data were as follows.

NMR- ¹ H (400 MHz, CDCl 3; ppm): δ = 7.10-7.15 (m, 4H), 7.28-7.30 (m, 4H),

7.31-7.35 (m, 20H), 7.47-7.50 (m, 4H), 7.56-7.61 (q, 4H).

NMR- ³¹ P (CDCl 3; ppm): δ = 30.28.

Photoluminescence (chloroform): 421 nm (exitation max .: 365 nm; see FIG. 4).

Mass spectrum: m / e = 726.82 (M &lt; + &gt;).

Scheme 7

Example 4 Preparation of Thin Film of Organic Light Emitting Compound

2,6-bis [2 (4-diphenylphosphinophenyl) vinyl] naphthalene synthesized according to Example 2 was vacuum deposited onto a glass substrate at a rate of 0.08 to 0.1 nm / sec under a vacuum of 5 x 10 ^-6 torr. To form a thin film having a thickness of 100 nm. The emission spectrum of the thin film was measured using a fluorescence spectrometer. Fig. 5 shows the emission spectrum of 2,6-bis [2 (4-diphenylphosphinophenyl) vinyl] naphthalene thus obtained. Referring to FIG. 5, it can be seen that this thin film exhibits a maximum peak at 483 nm. From this, it can be seen that light green light emission is shown.

Example 5 Fabrication of Organic EL Device

This example uses the 2,6-bis [2 (4-diphenylphosphinophenyl) vinyl] naphthalene synthesized according to Example 2 as a light emitting material of the light emitting layer, and according to a conventional method of the structure shown in FIG. It is for demonstrating manufacturing organic electroluminescent element. That is, on the indium-tin oxide (ITO) substrate, TPD was vacuum deposited at a rate of 0.08 to 0.1 nm / sec under a vacuum of 5 x 10 ^-6 torr to form a hole transport layer having a thickness of 40 nm on the hole transport layer. On top of that, 2,6-bis [2 (4-diphenylphosphinophenyl) vinyl] naphthalene synthesized in Example 2 was vacuum-deposited at a rate of 0.08 to 0.1 nm / sec under a vacuum of 5 x 10 ^-6 torr. A light emitting layer having a thickness of 100 nm was formed. Subsequently, Al was vacuum deposited on the light emitting layer to form a cathode layer having a thickness of 150 nm.

6 shows a current-voltage (I-V) characteristic curve of the organic EL device of Example 5. FIG.

7 shows the luminance-voltage (L-V) characteristic curve of the organic EL device of Example 5. FIG.

FIG. 8 shows the efficiency-voltage (Eff (cd / A) -V) characteristic curve of the organic EL device of Example 5. FIG.

6 to 8, the organic EL device of Example 5 exhibited a maximum efficiency of about 3.3 cd / A at an applied voltage of 17.75 V, at a current density of about 9.2 mA / cm ² and a luminance of about 303 cd / A. It can be seen that m ² .

As described above, the novel arylphosphine-based compound of the present invention has an excellent advantage that it can efficiently emit light even in a low electric field, and can be easily formed into a uniform amorphous film even by vacuum deposition. Therefore, by using this compound, an organic EL device can be produced at low cost. In addition, since the arylphosphine-based compound of the present invention has a high melting point and decomposition temperature, the organic EL device manufactured by using the arylphosphine-based compound may exhibit excellent durability because it is thermally stable.

Claims (5)

An aryl phosphine-based compound having a diaryl phosphino group represented by the general formula (1): [Formula 1] Here, X represents a substituted or unsubstituted arylene group of C6 to C21, Ar represents a substituted or unsubstituted aryl group of C6 to C21, respectively, the substituent when the arylene group or aryl group is substituted is a halogen group, a nitro group , A cyano group, a C1 to C6 alkyl group, a C1 to C6 halogenated alkyl group and a C1 to C6 alkoxy group. The arylphosphine-based compound having a diaryl phosphino group according to claim 1, wherein the arylene group X is a phenylene group, a biphenylene group or a naphthylene group. The light emitting material containing the aryl phosphine type compound which has the diaryl phosphino group of Claim 1 or 2. The organic electroluminescent element containing the aryl phosphine type compound which has the diaryl phosphino group of Claim 1 or 2. A method for producing an arylphosphine-based compound having a diarylphosphino group, which comprises reacting a diarylphosphino benzaldehyde compound with a diphosphonate compound or a diphosphonium halide compound.