JP2008231051A - Fluorene-benzothiadiazole compound and organic electroluminescence device using the same - Google Patents

Abstract

で示されるものである。発光素子材料は、このフルオレン化合物を含有するものである。有機電界発光素子は、陽極と陰極とからなる電極対の間にこの発光素子材料を含有する層を有している。
【選択図】 なしA novel fluorene compound having excellent optoelectronic properties, an organic light-emitting device material containing the fluorene compound, and an organic electroluminescence device capable of high-efficiency, high-brightness, and long-life light output are provided.
A fluorene compound has the following chemical formula (A):
[Chemical 1]

It is shown by. The light emitting element material contains this fluorene compound. The organic electroluminescent element has a layer containing the light emitting element material between an electrode pair composed of an anode and a cathode.
[Selection figure] None

Description

  The present invention relates to a novel fluorene compound that can be used as an organic light emitting device material, a light emitting device material using the fluorene compound, and an organic electroluminescent device.

  In recent years, research on organic electroluminescent devices has been actively conducted. The organic electroluminescence element emits light with high luminance at a low applied voltage, and can be made into a thin and light-emitting device, so that it is expected to be applied to a next generation display or the like.

  In order to obtain an organic electroluminescent device having excellent luminous efficiency and luminous luminance and a long lifetime, it is necessary to use an organic luminescent material having excellent optoelectronic characteristics as a constituent material of the organic electroluminescent device. Various organic compounds have been proposed as such light-emitting materials. Among them, fluorene and benzothiadiazole containing an aromatic ring are one of the most promising luminescent materials because they exhibit high luminous efficiency and high electron transport properties. Further, a copolymer of fluorene and benzothiadiazole is known as an excellent fluorescent material. Patent Document 1 discloses a hydrocarbon compound in which a condensed polycyclic aromatic ring other than an anthracene ring and a fluorene ring are directly bonded, and an organic electroluminescent element material and an organic electroluminescent element using the same. Yes.

  However, in order to obtain an organic electroluminescent device that emits light with higher efficiency and brightness and has a longer lifetime, a light emitting material having further excellent optoelectronic properties is required.

JP 2004-43349 A

  The present invention provides a novel fluorene compound having excellent optoelectronic properties, an organic light-emitting device material containing the fluorene compound, and an organic electroluminescent device capable of high-efficiency, high-brightness, and long-life light output. Objective.

（式（Ａ）中、−Ｒ_１は炭素数１〜１８のアルキル基、−Ｒ_２は炭素数１〜１８のアルキル基、カルボニル基、ニトロ基、シアノ基、カルバゾール基、置換基を有していてもよいアミノ基、置換基を有していてもよいフェニル基、置換基を有していてもよいスチリル基、置換基を有していてもよいアリール基、ｎは１〜３の数）で示されることを特徴とする。前記−Ｒ_１はヘキシル基であるとより好ましい。 The fluorene compound according to claim 1, which has been made to achieve the above object, has the following chemical formula (A):

(In the formula (A), -R ₁ has an alkyl group having 1 to 18 carbon atoms, -R ₂ has an alkyl group having 1 to 18 carbon atoms, a carbonyl group, a nitro group, a cyano group, a carbazole group, and a substituent. An optionally substituted amino group, an optionally substituted phenyl group, an optionally substituted styryl group, an optionally substituted aryl group, n is a number from 1 to 3 ). The —R ₁ is more preferably a hexyl group.

のうちのいずれかであることを特徴とする。 The fluorene compound according to claim 2 is the one described in claim 1, wherein the formula (A) is represented by the following formulas (1) to (7).

It is any one of these.

  A light emitting device material according to claim 3 contains the fluorene compound according to any one of claims 1 and 2.

  The organic electroluminescent element according to claim 4 is characterized in that a layer containing the light emitting element material according to claim 3 is provided between an electrode pair composed of an anode and a cathode.

  The fluorene compounds represented by the formulas (1) to (7) were synthesized for the first time according to the present invention. Since these fluorene compounds are excellent in temperature stability and chemical stability, and exhibit high fluorescence quantum yield, light emission efficiency, and excellent electron transport properties, they can be suitably used as fluorescent light emitting materials.

  An organic electroluminescent device manufactured using a light emitting device material containing the fluorene compound of the present invention emits light with high efficiency and high luminance even when the applied voltage is low. Therefore, this organic electroluminescent element is useful for display materials, illumination materials, solar cells, field effect transistors and the like.

BEST MODE FOR CARRYING OUT THE INVENTION

  Examples of the present invention will be described in detail below, but the scope of the present invention is not limited to these examples.

  The fluorene compound of the present invention is a π-conjugated oligomer having benzothiadiazole at both ends of fluorene.

  As a preferred example of the fluorene compound of the present invention, the compound represented by the chemical formula (5) is synthesized according to the following chemical reaction formula.

出発物質である９，９−ジヘキシルフルオレン−２，７−ジボロン酸に、４，７−ジブロモ−２，１，３−ベンゾチアジアゾールと、触媒であるトリフェニルホスフィンパラジウム（Ｐｄ（ＰＰｈ_３）_４）とを加えて、窒素気流下でSuzukiカップリング反応を行い、（ｉ）で示した中間体を合成する。溶媒としては、テトラヒドロフラン（ＴＨＦ）とトルエンとを使用する。

9,9-dihexylfluorene-2,7-diboronic acid as a starting material, 4,7-dibromo-2,1,3-benzothiadiazole and triphenylphosphine palladium as a catalyst (Pd (PPh ₃ ) ₄ ) And the Suzuki coupling reaction is carried out under a nitrogen stream to synthesize the intermediate shown in (i). Tetrahydrofuran (THF) and toluene are used as the solvent.

1-Vinyl-4- (2,2-diphenyl-vinyl) -benzene is introduced into the intermediate of (i). When palladium acetate (Pd (OAc) ₂ ) and tris (2-methylphenyl) phosphine were used as catalysts and dimethylformamide (DMF) and tributylamine were used as a solvent and stirred at 90 ° C. for 2 days, the chemical formula (5 ) Can be obtained (molecular weight 1163.58).

The synthesized compounds were confirmed to be produced by proton nuclear magnetic resonance ( ¹ H-NMR), carbon nuclear magnetic resonance ( ¹³ C-NMR), matrix-assisted laser desorption / ionization time-of-flight mass spectrometry (MALDI-TOF-Ms), Identify.

  The fluorene compounds represented by the chemical formulas (1) to (4), (6) and (7) can also be synthesized by the same reaction.

-R ₂ in the chemical formula (A) is an aryl group, a carbonyl group, a cyano group, a nitro group, an amino group, in addition to the group introduced as -R _{2 in the} chemical formulas (1) to (7). It may be a carbazole group, and each of these groups may have a substituent.

Fluorene compounds, depending on the type of substituents introduced as -R _2, showing a different fluorescent emission. The compound represented by the chemical formula (5) having stilbene as —R ₂ exhibits orange light emission, and the compound represented by the chemical formula (2) having triphenylamine as —R ₂ exhibits red light emission.

  The fluorene compound has a fluorene-benzothiadiazole monomer as a basic skeleton, but a fluorene compound having a benzothiadiazole arranged at one end of the fluorene may be a monomer unit, and a trimer thereof may be a basic skeleton.

  The light emitting device material of the present invention contains the fluorene compound as a fluorescent dye. The light emitting device material is preferably used as a constituent material of the light emitting layer of the organic electroluminescent device, but may be contained in the hole injection layer, hole transport layer, electron injection layer, electron transport layer, etc. of the organic electroluminescent device. Good.

  The organic electroluminescent element of the present invention comprises the above-described light emitting element material in at least one layer present between an anode and a cathode provided on a substrate. The layer containing the light emitting element material is particularly preferably a light emitting layer.

  The method for forming the layer containing the light emitting element material is not particularly limited. For example, the film is formed using a known method such as a wet process such as a printing method, a spin coating method, or a sputtering method, or a dry process such as a vacuum evaporation method.

  As the substrate, for example, a transparent substrate such as a glass substrate or a quartz substrate, or an opaque substrate such as a metal substrate or a ceramic substrate can be used.

  The material of the anode is preferably a material having a large work function, for example, a simple metal such as gold, platinum, nickel, palladium, cobalt, selenium, vanadium; an alloy of these metals; tin oxide, zinc oxide, indium tin oxide. (ITO), and metal oxides such as zinc indium oxide. These anode materials may constitute an anode alone or may be used in combination.

  The material of the cathode is preferably a material having a small work function, for example, simple metals such as lithium, sodium, potassium, calcium, magnesium, aluminum, indium, silver, lead, tin, chromium; alloys of these metals It is done. These cathode materials may constitute a cathode alone or in combination.

  The organic electroluminescent element may be provided with layers such as a hole injection layer, a hole transport layer, a hole block layer, an electron transport layer, and an electron injection layer in addition to the light emitting layer. These layers may be single layers or multilayers, and may be organic compound layers or inorganic compound layers.

Specifically, for example, copper phthalocyanine or 4,4-bis (3-methylphenylphenylamino) biphenyl (mTDATA) as the hole injection layer, and 4,4,4-tris (3-methylphenylphenylamino) as the hole transport layer. ) Triphenylamine (TPD), N, N′-bis (1-naphthyl) -N, N′-diphenylbenzidine (NPD), 2,9-dimethyl-4,7-diphenyl-1,10 as a hole blocking layer -Phenanthroline (basocuproin; BCP), bis (2-methyl-8-quinolinolate) (p-phenylphenolate) aluminum (BAlq), or bathophen can be used. Alternatively, aluminum tris 8-hydroxyquinoline (Alq ₃ ) or 1,3,5-tris (1-phenyl-2-benzimidazolyl) benzene (TPBi) may be used as the electron transport layer.

  Examples of synthesizing the fluorene compound of the present invention are shown in Synthesis Examples 1-6.

Synthesis Example 1 Synthesis of 2,7-bis [(4-methyl) -2,1,3-benzothiadiazole] -9,9-dihexylfluorene (fluorene compound represented by the above chemical formula (1)) THF 5 ml and toluene In a mixed solution of 4 ml and 3 ml of 2N aqueous potassium carbonate solution, 0.1 g (2.37 × 10 ⁻⁴ mol) of 9,9-dihexylfluorene-2,7-diboronic acid and 4-bromo-7-methyl-2 were added. , 1,3-benzothiadiazole 0.12 g (5.21 × 10 ⁻⁴ mol) was added and dissolved by stirring for 30 minutes under a nitrogen stream. Thereto was added 0.006 g (4.74 × 10 ⁻⁶ mol) of triphenylphosphine palladium, and the mixture was further stirred for 10 minutes, and then stirred and refluxed at 70 ° C. for 2 days. Liquid separation was performed with ether / water to extract an ether layer, dehydrated with magnesium sulfate, and then concentrated under reduced pressure. The product was purified using a silica gel column (petroleum ether: dichloromethane = 1: 1), further purified by high performance liquid chromatography (HPLC), and then concentrated under reduced pressure to obtain the desired product. The obtained product was identified by ¹ H-NMR and ¹³ C-NMR. In addition, NMR spectrometer AVANCE400 (made by Nippon Bruker) was used for NMR measurement.

Yield (yield): 0.08 g (53%)
¹ H-NMR (CDCl ₃ , 400.13MHz): δ = 7.97 (d, J = 8.0Hz, 2H, ArH), 7.92 (s, 2H, ArH), 7.88 (d, J = 8.0Hz, 2H, ArH) , 7.69 (d, J = 6.8Hz, 2H, ArH), 7.48 (d, J = 7.2Hz, 2H, ArH), 2.81 (s, 6H, Ar-CH ₃ ), 2.08 (m, 4H, Ar-CH ₂ -C ₅ H ₁₁ ), 1.12 (m, 12H, -CH _2- ), 0.89 (m, 4H, -CH ₂ -CH ₃ ), 0.76 (t, J = 7.2Hz, 6H,-(CH ₂ ) ₅ -CH ₃ ),
¹³ C-NMR (CDCl ₃ ): δ = 156.17,153.69,151.64,140.68,136.51,132.52,130.38,128.41,128.12,127.76,123.84,119.89,55.38,40.25,31.50,29.78,23.97,22.60,17.99,14.04

(Synthesis Example 2) 2,7-bis [4- (N, N-diphenylamino) phenyl] -2,1,3-benzothiadiazole-9,9-dihexylfluorene (a fluorene compound represented by the chemical formula (2)) ) Synthesis

(2-1)
To a mixed solution of 6 ml of THF, 5 ml of toluene and 4 ml of 2N aqueous potassium carbonate solution, 0.25 g (5.29 × 10 ⁻⁴ mol) of 9,9-dihexylfluorene-2,7-diboronic acid and 4,7-dibromo- 0.56 g (1.89 × 10 ⁻³ mol) of 2,1,3-benzothiadiazole was added and dissolved by stirring for 30 minutes under a nitrogen stream. To this was added 0.014 g (1.18 × 10 ⁻⁶ mol) of triphenylphosphine palladium, and the mixture was further stirred for 10 minutes, and then stirred and refluxed at 70 ° C. for 2 days. Liquid separation was performed with ether / water to extract an ether layer, dehydrated with magnesium sulfate, and then concentrated under reduced pressure. The product was purified using a silica gel column (petroleum ether: dichloromethane = 8: 2), further purified by high performance liquid chromatography (HPLC), and then concentrated under reduced pressure to obtain the desired product. The obtained product was identified by ¹ H-NMR and MALDI-TOF-Ms. For measurement of MALDI-TOF-Ms, Voyager DE Pro (manufactured by PerSeptive Biosystems) was used.

Yield (yield): 0.45 g (53%)

(2-2)
To a mixed solution of 4 ml of THF, 3 ml of toluene and 2 ml of 2N aqueous potassium carbonate solution, 0.13 g (1.71 × 10 ⁻⁴ mol) of the compound obtained in 2-1, and 0 of 4- (diphenylamino) phenylboronic acid .12 g (4.27 × 10 ⁻⁴ mol) was added and dissolved by stirring for 30 minutes under a nitrogen stream. Thereto was added 0.004 g (3.42 × 10 ⁻⁶ mol) of triphenylphosphine palladium, and the mixture was further stirred for 10 minutes, and then stirred and refluxed at 70 ° C. for 2 days. Liquid separation was performed with ether / water to extract an ether layer, dehydrated with magnesium sulfate, and then concentrated under reduced pressure. The product was purified using a silica gel column (petroleum ether: dichloromethane = 1: 1), further purified by high performance liquid chromatography (HPLC), and then concentrated under reduced pressure to obtain the desired product. The obtained product was identified by ¹ H-NMR and ¹³ C-NMR.

Yield (yield): 0.15 g (79%)
¹ H-NMR (CDCl ₃ , 400.13 MHz): δ = 8.04 (d, J = 8.0 Hz, 1H, ArH), 7.99 (s, 2H, ArH), 7.91 (m, 5H, ArH), 7.86 (d, 1H, J = 7.6Hz, ArH), 7.80 (d, J = 7.6Hz, 1H, ArH), 7.30 (t, J = 8.4Hz, 8H, ArH), 7.22 (m, 12H, ArH), 7.15 (t , J = 7.6Hz, 2H, ArH), 7.07 (t, J = 7.6Hz, 4H, ArH), 6.75 (t, J = 7.6Hz, 1H, ArH), 6.68 (d, J = 8.4Hz, 1H, ArH), 2.11 (m, 4H , Ar-CH 2 -C 5 H 11), 1.13 (m, 12H, -CH 2 -), 0.91 (m, 4H, -CH 2 -CH 3), 0.77 (t, J = 7.2Hz, 6H,-(CH ₂ ) ₅ -CH ₃ ),
¹³ C-NMR (CDCl ₃ ): δ = 154.41,154.22,151.73,147.52,140.86,136.46,131.03,129.97,129.38,128.29,128.03,127.36,124.96,123.97,123.35,122.92,120.00,115.11,77.33,77.01 , 76.70,55.45,40.30,31.53,29.80,24.01,22.61,14.05

(Synthesis Example 3) 2,7-bis-4- (N, N-diphenylamino) -2,1,3-benzothiadiazole-9,9-dihexylfluorene (fluorene compound represented by the above chemical formula (3)) Synthesis To 5 ml of dry toluene, 0.15 g (1.97 × 10 ⁻⁴ mol) of the compound obtained in 2-1, 0.073 g (4.34 × 10 ⁻⁴ mol) of diphenylamine, and tert-butoxy sodium 0.076 g (7.89 × 10 ⁻⁴ mol) was added and dissolved by stirring for 30 minutes under a nitrogen stream. Thereto was added 0.002 g (9.86 × 10 ⁻⁶ mol) of palladium acetate, and the mixture was further stirred for 10 minutes, and then 0.01 ml (3.94 × 10 ⁻⁵ mol) of tri-tert-butylphosphine was added. Stir overnight. Liquid separation was performed with ether / water to extract an ether layer, dehydrated with magnesium sulfate, and then concentrated under reduced pressure. The product was purified using a silica gel column (petroleum ether: dichloromethane = 1: 1), further purified by high performance liquid chromatography (HPLC), and then concentrated under reduced pressure to obtain the desired product. The obtained product was identified by ¹ H-NMR, ¹³ C-NMR, and MALDI-TOF-Ms.

Yield (yield): 0.18 g (100%)
¹ H-NMR (CDCl ₃ , 400.13 MHz): δ = 7.99 (d, J = 8.0 Hz, 2H, ArH), 7.94 (s, 2H, ArH), 7.88 (d, J = 8.0 Hz, 2H, ArH) , 7.69 (d, 2H, J = 7.6Hz, ArH), 7.28 (t, J = 7.6Hz, 10H, ArH), 7.11 (m, 12H, ArH), 2.08 (m, 4H, Ar-CH ₂ -C ₅ H ₁₁ ), 1.11 (m, 12H, -CH _2- ), 0.87 (m, 4H, -CH ₂ -CH ₃ ), 0.75 (t, J = 7.2Hz, 6H,-(CH ₂ ) ₅ -CH ₃ )
¹³ C-NMR (CDCl ₃ ): δ = 151.62,147.73,138.90,136.34,130.06,129.24,128.29,128.04,124.08,123.89,123.69,123.06,119.91,77.33,77.02,76.70,55.36,40.32,31.53,29.80 , 23.96,22.60,14.05
MALDI-TOF-Ms (Dithranol): m / z = 937.23, calculated for C ₆₁ H ₅₆ N ₆ S ₂ ; 937.27

Synthesis Example 4 Synthesis of 2,7-bis (4-carbazol-9-yl) -2,1,3-benzothiadiazole-9,9-dihexylfluorene (fluorene compound represented by the above chemical formula (4)) Drying To 10 ml of toluene, 0.30 g (3.94 × 10 ⁻⁴ mol) of the compound obtained in 2-1, 0.15 g (8.68 × 10 ⁻⁴ mol) of carbazole, 0. 15 g (7.89 × 10 ⁻⁵ mol) was added and dissolved by stirring for 30 minutes under a nitrogen stream. Thereto was added 0.004 g (1.97 × 10 ⁻⁵ mol) of palladium acetate, and the mixture was further stirred for 10 minutes, and then 0.019 ml (7.89 × 10 ⁻⁵ mol) of tri-tert-butylphosphine was added and 100% was added. Stir overnight at ° C. Liquid separation was performed with ether / water to extract an ether layer, dehydrated with magnesium sulfate, and then concentrated under reduced pressure. The product was purified using a silica gel column (petroleum ether: dichloromethane = 1: 1), further purified by high performance liquid chromatography (HPLC), and then concentrated under reduced pressure to obtain the desired product.

Yield (yield): 0.19 g (51%)

Synthesis Example 5 2,7-bis [4- (2,2-diphenyl-vinyl) -phenyl] -2,1,3-benzothiadiazole-9,9-dihexylfluorene (shown by the above chemical formula (5)) Synthesis of fluorene compounds)

(5-1)
To 1 g (4.0 × 10 ³ mol) of 4-bromobenzyl bromine was added 2.1 ml (1.2 × 10 ² mol) of triethylphosphine, and the mixture was stirred and refluxed at 145 ° C. overnight. Excess triethylphosphine was removed by distillation under reduced pressure to give 1-bromo-4- (diethylphosphinoylmethyl) benzene.

(5-2)
To 20 ml of THF, 1.12 g (1.0 × 10 ⁻² mol) of tert-butoxypotassium was added and stirred in an ice bath. Thereto, 0.73 g (4.0 × 10 ⁻³ mol) of benzophenone and 1.23 g (4.0 × 10) of 1-bromo-4- (diethylphosphinoylmethyl) benzene obtained in 5-1 in 10 ml of THF were obtained. 10 ⁻³ mol) was slowly added dropwise and stirred and refluxed at 70 ° C. overnight. The reaction mixture was poured into ice water and neutralized with hydrochloric acid. Thereafter, the mixture was separated with ether / water to extract the ether layer, dehydrated with magnesium sulfate, and concentrated under reduced pressure. Purification was performed using a silica gel column (petroleum ether: dichloromethane = 1: 1), further purification was performed by high performance liquid chromatography (HPLC), and then concentrated under reduced pressure to give 1-bromo-4- (2,2-diphenyl). Vinyl) benzene was obtained.

Yield (yield): 0.89 g (66%)

(5-3)
To 5 ml of dry toluene, 0.47 g (1.40 × 10 ⁻³ mol) of 1-bromo-4- (2,2-diphenylvinyl) benzene obtained in 5-2 and 2,6-ditert- 0.03 g (1.36 × 10 ⁻⁴ mol) of butyl-4-methylphenol was added and dissolved by stirring for 30 minutes under a nitrogen stream. Thereto was added 0.014 g (2.80 × 10 ⁻⁵ mol) of triphenylphosphine palladium, and the mixture was further stirred for 10 minutes, and then 0.49 ml (1.68 × 10 ⁻³ mol) of tributyl (vinyl) tin was added. Stir at 100 ° C. overnight. The ether layer was extracted with an ether / potassium fluoride aqueous solution, dehydrated with magnesium sulfate, and concentrated under reduced pressure. Purification was performed using a silica gel column (petroleum ether: dichloromethane = 8: 2), further purification was performed by high performance liquid chromatography (HPLC), and then concentrated under reduced pressure to give 1-vinyl-4- (2,2-diphenyl). Vinyl) benzene was obtained.

Yield (yield): 0.18 g (45%)

(5-4)
To 8 ml of dry toluene, 0.22 g (2.89 × 10 ⁻⁴ mol) of the compound obtained in 2-1 and 1-vinyl-4- (2,2-diphenylvinyl) obtained in 5-3 0.18 g (6.36 × 10 ⁻⁴ mol) of benzene was dissolved, and 0.002 g (1.16 × 10 ⁻⁵ mol) of palladium acetate and 0.018 g of tris (2-methylphenyl) phosphine ( 5.78 × 10 ⁻⁵ mol) was added and stirred for 20 minutes under a nitrogen stream. Thereto was added 3.0 ml (1.26 × 10 ⁻² mol) of dry tributylamine, and the mixture was stirred and refluxed at 90 ° C. for 2 days. The solvent was concentrated under reduced pressure, purified using a silica gel column (petroleum ether: dichloromethane = 1: 1), further purified by high performance liquid chromatography (HPLC), and then concentrated under reduced pressure to obtain the desired product. The obtained product was identified by ¹ H-NMR, ¹³ C-NMR, and MALDI-TOF-Ms.

Yield (yield): 0.22 g (67%)
¹ H-NMR (CDCl ₃ , 400.13 MHz): δ = 8.01 (d, J = 7.6 Hz, 2H, ArH), 7.97 (d, J = 7.2 Hz, 2H, ArH), 7.90 (d, J = 8.0 Hz , 2H, ArH), 7.79 (d, 2H, J = 7.6Hz, ArH), 7.76 (d, J = 7.6Hz, 2H, ArH), 7.67 (s, 1H, ArH), 7.62 (s, 1H, ArH ), 7.45 (d, J = 8.4Hz, 4H, ArH), 7.31 (m, 22H, ArH), 7.06 (d, J = 8.4Hz, 4H, -CH = CH-), 7.00 (s, 2H, ArH ), 2.11 (m, 4H, Ar-CH ₂ -C ₅ H ₁₁ ), 1.13 (m, 12H, -CH _2- ), 0.88 (m, 4H, -CH ₂ -CH ₃ ), 0.77 (t, J = 6.8Hz, 6H,-(CH ₂ ) ₅ -CH ₃ )
¹³ C-NMR (CDCl ₃ ): δ = 143.33,137.42,136.38,135.89,132.78,130.40,129.98,129.45,128.76,128.24,127.79,127.62,126.75,126.57,124.28,120.01,77.33,77.01,76.69,31.50 , 29.77,23.97,22.60,14.06
MALDI-TOF-Ms (Dithranol): m / z = 1163.51, calculated for C ₈₁ H ₇₀ N ₄ S ₂ ; 1163.58

Synthesis Example 6 2,7-bis {4- [4- (10,11-dihydro-dibenzocycloheptane-5-ylidenemethyl) -phenyl] -2,1,3-benzothiadiazole} -9,9-dihexyl Synthesis of fluorene (fluorene compound represented by the chemical formula (6))

(6-1)
To 20 ml of THF, 1.12 g (1.0 × 10 ⁻² mol) of tert-butoxypotassium was added and stirred in an ice bath. Thereto, 0.83 g (4.0 × 10 ⁻³ mol) of dibenzosuberone in 10 ml of THF and 1.23 g (4. 4 of 1-bromo-4- (diethylphosphinoylmethyl) benzene obtained in 5-1. 0 × 10 ⁻³ mol) was slowly added dropwise and stirred and refluxed at 70 ° C. overnight. The reaction mixture was poured into ice water and neutralized with hydrochloric acid. Thereafter, the mixture was separated with ether / water to extract the ether layer, dehydrated with magnesium sulfate, and concentrated under reduced pressure. Purification is performed using a silica gel column (petroleum ether: dichloromethane = 1: 1), and further purification is performed by high performance liquid chromatography (HPLC), followed by concentration under reduced pressure to give 5- (4-bromobenzylidene) -10,11. -Dihydro-5H-dibenzocycloheptane was obtained.

Yield (yield): 0.41 g (44%)

(6-2)
In 5 ml of dry toluene, 0.40 g (1.11 × 10 ⁻³ mol) of the compound obtained in 6-1 and 0.03 g (1.36) of 2,6-ditert-butyl-4-methylphenol were obtained. × 10 ⁻⁴ mol) was added and dissolved by stirring for 30 minutes under a nitrogen stream. Thereto was added 0.026 g (2.21 × 10 ⁻⁵ mol) of triphenylphosphine palladium, and the mixture was further stirred for 10 minutes, and then 0.39 ml (1.33 × 10 ⁻³ mol) of tributyl (vinyl) tin was added. Stir at 100 ° C. overnight. The ether layer was extracted with an ether / potassium fluoride aqueous solution, dehydrated with magnesium sulfate, and concentrated under reduced pressure. Purification is performed using a silica gel column (petroleum ether: dichloromethane = 8: 2), and further purification is performed by high performance liquid chromatography (HPLC), followed by concentration under reduced pressure, and 5- (4-vinylbenzylidene) -10,11. -Dihydro-5H-dibenzocycloheptane was obtained.

Yield (yield): 0.20 g (59%)

(6-3)
In 5 ml of dry DMF, 0.15 g (1.97 × 10 ⁻⁴ mol) of the compound obtained in 2-1 and 0.13 g (4.34 × 10 ⁻⁴ mol) of the compound obtained in 6-2 Further, 0.002 g (7.89 × 10 ⁻⁶ mol) of palladium acetate and 0.012 g (3.94 × 10 ⁻⁵ mol) of tris (2-methylphenyl) phosphine were added, and nitrogen was added. Stir for 20 minutes under air flow. Thereto was added 3.0 ml (1.26 × 10 ⁻² mol) of dry tributylamine, and the mixture was stirred and refluxed at 90 ° C. for 2 days. The solvent was concentrated under reduced pressure, purified using a silica gel column (petroleum ether: dichloromethane = 1: 1), further purified by high performance liquid chromatography (HPLC), and then concentrated under reduced pressure to obtain the desired product.

Yield (yield): 0.13 g (54%)

(Ultraviolet / visible (UV-Vis) spectrum measurement)
Using a V-650 spectrophotometer (manufactured by JASCO Corporation), UV-Vis spectrum measurement of the compounds obtained in Synthesis Examples 1, 2, 3, and 5 in dichloromethane was performed. The results are shown in FIG.

(Fluorescence spectrum measurement)
Using an FP-750 spectrofluorometer (manufactured by JASCO Corporation), the fluorescence spectra at the excitation wavelength of fluorene of the compounds obtained in Synthesis Examples 1, 2, 3, and 5 were measured. The results are shown in FIG.

  As a result of UV-Vis spectrum measurement, a peak derived from fluorene was observed in the vicinity of 310 nm for all the compounds. Further, in the compounds of Synthesis Examples 2, 3, and 5, a peak derived from benzothiadiazole was observed around 460 to 490 nm. Furthermore, peaks derived from the peripheral substituents of fluorene-benzothiadiazole were observed at around 340 nm for the compounds of Synthesis Example 2 and Synthesis Example 3 and at around 350 nm for the compound of Synthesis Example 5.

  As a result of the fluorescence spectrum measurement, a fluorescence peak derived from benzothiadiazole was observed around 570 nm in the compound of Synthesis Example 5, and a fluorescence peak derived from triphenylamine and diphenylamine was observed around 630 nm in the compounds of Synthesis Examples 2 and 3, respectively. It was done.

  When the peaks of the UV-Vis spectrum and the fluorescence spectrum of the compounds of Synthesis Examples 2, 3, and 5 are compared with the peak of the compound of Synthesis Example 1, it can be seen that they are red-shifted. This red shift is due to an increase in conjugation length for the compound of Synthesis Example 5, and due to an intramolecular interaction associated with the introduction of an amino group which is a donor substituent for the compounds of Synthesis Examples 2 and 3. it is conceivable that.

(Fluorescence quantum yield measurement)
Using an organic EL quantum yield measuring apparatus (manufactured by Hamamatsu Photonics), the fluorescence quantum yield at each excitation wavelength was measured for the compounds obtained in Synthesis Examples 1-6. The results are shown in Table 1.

表１から明らかなとおり、いずれの化合物でも良好な蛍光量子収率が得られた。

As is clear from Table 1, good fluorescence quantum yield was obtained with any compound.

  Next, Examples 1 to 4 show examples in which organic electroluminescent elements (EL elements) were produced using the compounds obtained in Synthesis Examples 2, 3, 4, and 6.

(Example 1)
The element structure is ITO / PEDOT-PSS / the compound of Synthesis Example 2 and FlFl / LiF / Ca / Al.

  On a glass substrate, ITO was formed into a film having a thickness of 150 nm by sputtering as an anode, and was successively subjected to ultrasonic cleaning and drying with a neutral detergent, an alkaline detergent, pure water, acetone, and isopropyl alcohol (IPA).

  Next, a poly (3,4-ethylenedioxythiophene) -poly (4-styrenesulfonate) (PEDOT-PSS) layer, which is a conductive polymer, was formed as a hole transport layer on the anode. PEDOT-PSS (Baytron P AI4083) was formed into a film with a film thickness of 50 nm by spin coating (2000 rpm), dried at 200 ° C., and baked.

  Next, a layer of the compound obtained in Synthesis Example 2 was formed as a light emitting layer on the hole transport layer. 4.5 mg of the compound of Synthesis Example 2 and 25.5 mg (15 wt%) of 2,7-bis (7,9,10-triphenylfluoranthenyl) -9,9 ′ dihexylfluorene (FlFl) It melt | dissolved in p-xylene 1.0g, and after filtering, it formed into a film with the spin coat method (2000 rpm), dried and baked at 140 degreeC, and obtained the light emitting layer with a film thickness of 80 nm.

  Next, lithium fluoride (LiF), calcium (Ca), and aluminum (Al) were vapor-deposited on the light emitting layer as a cathode. Lithium fluoride is deposited at a film thickness of 0.1 angstrom / second by a vacuum deposition method at a film thickness of 0.5 nm, and then a calcium film is deposited thereon at a film deposition speed of 0.3 angstrom / second at a film thickness of 20 nm. A film was formed with a thickness, and then aluminum was formed thereon with a film thickness of 200 nm at a film formation rate of 1 to 5 angstroms / second by a vacuum deposition method, thereby manufacturing an EL element.

(Example 2)
The element structure is ITO / PEDOT-PSS / the compound of Synthesis Example 3, FlFl / LiF / Ca / Al.

  An EL device was produced in the same manner as in Example 1 except that the compound of Synthesis Example 3 was used instead of the compound of Synthesis Example 2.

(Example 3)
The element configuration is ITO / PEDOT-PSS / the compound of Synthesis Example 4, FlFl / LiF / Ca / Al.

  An EL device was produced in the same manner as in Example 1 except that the compound of Synthesis Example 4 was used instead of the compound of Synthesis Example 2.

Example 4
The element configuration is ITO / PEDOT-PSS / the compound of Synthesis Example 6, FlFl / LiF / Ca / Al.

  An EL device was produced in the same manner as in Example 1 except that the compound of Synthesis Example 6 was used instead of the compound of Synthesis Example 2.

(Measurement of current density and emission luminance)
Using EL1003 (manufactured by Precise Gauge), the current density and light emission luminance of the EL elements produced in Examples 1 to 4 were measured. The measurement results of the current density and light emission luminance of the EL element produced in Example 1 are shown in FIG. 3A, the excitation wavelength of the element is shown in FIG. 3B, the current density of the EL element produced in Example 2, FIG. 4A shows the measurement result of the light emission luminance, FIG. 4B shows the excitation wavelength of the device, and FIG. 5A shows the measurement result of the current density and light emission luminance of the EL device manufactured in Example 3. FIG. 5B shows the excitation wavelength of the device, FIG. 6A shows the measurement results of the current density and light emission luminance of the EL device produced in Example 4, and FIG. 6B shows the excitation wavelength of the device. Respectively.

  As apparent from FIGS. 3 to 6, the EL element of Example 1 is around 580 nm, the EL element of Example 2 is around 610 nm, the EL element of Example 3 is around 550 nm, and the EL element of Example 4 is Each had an emission peak in the vicinity of 560 nm. Moreover, the EL element of each Example had favorable light emission luminance, and had excellent electroluminescence characteristics.

  From the above results, it was confirmed that the fluorene compound of the present invention is useful as an EL device material.

  Similarly, excellent light emission luminance was obtained for EL devices manufactured using the compounds of Synthesis Examples 1 and 5.

It is a UV-Vis spectrum of a fluorene compound to which the present invention is applied. It is a fluorescence spectrum of a fluorene compound to which the present invention is applied. 4 is a graph obtained by measuring current density and light emission luminance of an EL element manufactured in Example 1. FIG. 4 is a graph obtained by measuring current density and light emission luminance of an EL element manufactured in Example 2. FIG. 6 is a graph obtained by measuring current density and light emission luminance of an EL device manufactured in Example 3. FIG. 6 is a graph obtained by measuring current density and light emission luminance of an EL element manufactured in Example 4. FIG.

Claims (4)

The following chemical formula (A)

(In the formula (A), -R ₁ has an alkyl group having 1 to 18 carbon atoms, -R ₂ has an alkyl group having 1 to 18 carbon atoms, a carbonyl group, a nitro group, a cyano group, a carbazole group, and a substituent. An optionally substituted amino group, an optionally substituted phenyl group, an optionally substituted styryl group, an optionally substituted aryl group, n is a number from 1 to 3 The fluorene compound characterized by the above-mentioned. The formula (A) is represented by the following formulas (1) to (7).

The fluorene compound according to claim 1, wherein the fluorene compound is any one of the above.   A light emitting device material comprising the fluorene compound according to claim 1.   The organic electroluminescent element characterized by having a layer containing the light emitting element material of Claim 3 between the electrode pair which consists of an anode and a cathode.

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