JP2006008628A - Blue light emitting compound and light emitting element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new light emitting compound and a light emitting element utilizing the compound. <P>SOLUTION: The blue light emitting compound has a fluorene skeleton at the center of the molecule and bears aromatic groups via methylene groups on both sides of the fluorene skeleton and the aromatic groups are symmetric or asymmetric. The light emitting compound is used to produce light-emitting elements. One example of the compound is given in formula (1). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a blue light emitting compound and a light emitting element, and more particularly to a blue light emitting compound capable of emitting blue light and a light emitting element capable of emitting blue light.

As a compound capable of emitting blue light, a novel substance having a general formula of Ar ₂ —CH ₂ —Ar—CH ₂ —Ar 1 (where Ar is a lenene group, a naphthyl group, or an anthryl group) has been proposed. (Patent Document 1). This new substance is a robust substance that emits blue light, has high color purity, and emits light with high luminance.

  In the technical field of organic EL, various blue light emitting compounds are being searched in addition to the above-mentioned novel compounds capable of emitting blue light.

JP2004-18401

  An object of the present invention is to provide a novel compound capable of emitting blue light and a light-emitting element having light emission characteristics similar to or superior to those of the above-described compounds in addition to the blue light-emitting compound.

As means for solving the problems,
Claim 1 is a blue light-emitting compound characterized by having a structure represented by the following formula (1):

(However, in Formula (1), -Ar- is a fluorene skeleton represented by Formula (2), Ar1- and Ar2- are aromatic substituents, and they are the same or different from each other. Is also good.)

(However, in the formula (2), two Rs each represent an alkyl group having 1 to 12 carbon atoms, and the two Rs may be the same or different.)
A second aspect of the present invention is the blue light-emitting compound according to the first aspect, wherein the Ar1 and Ar2 are aromatic substituents represented by any one of the following formulas (3) to (5):

(However, in the formula, R ¹ represents an alkyl group that may be substituted by a fluorine atom having 1 to 5 carbon atoms. M represents an integer of 0 or ¹ to 5. A plurality of R ¹ may be the same. R ² represents an alkyl group which may be substituted by a fluorine atom having 1 to 5 carbon atoms, n represents an integer of 0 or 1 to 3. A plurality of R ² are the same. R ³ represents an alkyl group which may be substituted by a fluorine atom having 1 to 5 carbon atoms, p represents an integer of 0 or 1 to 4. A plurality of R ³ are the same. In addition, R ² and R ³ may be the same or different, and R ⁴ is an alkyl that may be substituted by a fluorine atom having 1 to 5 carbon atoms. a group .R ⁵ is .q showing an alkyl group which may be substituted with fluorine atoms of 1 to 5 carbon atoms, an integer Codes 0 to 3.. multiple ^{R 5} It is the same or may be different also. In addition, it may be different even with the same R ⁴ and R ^5.)
According to a third aspect of the present invention, there is provided a light emitting element comprising a light emitting layer containing the blue light emitting compound represented by the general formula (1) between a pair of electrodes.

According to the present invention, a novel blue light-emitting compound can be provided. Further, the novel blue light-emitting compound according to the present invention has a fluorene skeleton at the center of the molecule, and has a unique characteristic that aromatic groups are bonded symmetrically or asymmetrically via methylene groups on the left and right sides of the fluorene skeleton. It has a molecular skeleton. Since the π electron in the fluorene skeleton and the π electron in the aromatic group bonded to both sides of the fluorene skeleton via a methylene group are separated by a methylene group, an alkylene group having 2 or more carbon atoms [-(- CH ₂ ) n—] is not separated, and the π electrons in the fluorene skeleton and the π electrons in the aromatic group bonded to both sides of the fluorene skeleton via a methylene group are not conjugated, Since it is no longer in an unaffected state, the reason is not clear, but an electronic state capable of emitting blue light is realized by ultraviolet irradiation. In addition, since it has a fluorene skeleton and an aromatic ring skeleton, the entire molecule has a stable structure and is difficult to deteriorate. Therefore, a light-emitting element using this blue light-emitting compound having a durable al molecular skeleton that hardly deteriorates can realize light emission with a long lifetime with little deterioration with time.

  The novel blue light-emitting compound according to the present invention has a structure represented by the formula (1).

  However, in formula (1), -Ar- is a fluorene skeleton represented by formula (2), and Ar1- and Ar2- are aromatic substituents, which may be the same or different from each other. good.

  However, in the formula (2), two Rs each represent an alkyl group having 1 to 12 carbon atoms, and the two Rs may be the same as or different from each other.

  Examples of the alkyl group represented by R include a methyl group, an ethyl group, a propyl group, a butyl group, and a decyl group. Which of these various alkyl groups is selected can be determined in consideration of the characteristics of the blue light-emitting compound. For example, if it is intended to improve the solubility of the blue light-emitting compound in a solvent, an alkyl group having a long carbon chain is preferable, and therefore an alkyl group having 8 to 12 carbon atoms is preferable. In order to influence the electron withdrawing effect on the π-electron state on the benzene ring in the fluorene skeleton represented by the formula (2), the R is preferably a methyl group. Preference is given to two Rs being the same alkyl group, specifically, both being the same methyl group.

  Suitable Ar1- and Ar2- are represented by formulas (3) to (5).

However, In the formula, R ¹ is an alkyl group which may be substituted with fluorine atoms of 1 to 5 carbon atoms. m shows the integer of 0, 1-5. The plurality of R ¹ may be the same or different. R ² represents an alkyl group that may be substituted by a fluorine atom having 1 to 5 carbon atoms. n shows the integer of 0, 1-3. A plurality of R ² may be the same or different. R ³ represents an alkyl group that may be substituted by a fluorine atom having 1 to 5 carbon atoms. p shows the integer of 0, 1-4. A plurality of R ³ may be the same or different. R ² and R ³ may be the same or different. R ⁴ represents an alkyl group that may be substituted by a fluorine atom having 1 to 5 carbon atoms. R ⁵ represents an alkyl group that may be substituted by a fluorine atom having 1 to 5 carbon atoms. q shows the integer of 0, 1-4. A plurality of R ⁵ may be the same or different. R ⁴ and R ⁵ may be the same or different.

When R ¹ , R ² , R ³ , R ⁴ and R ⁵ represent an alkyl group, examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group and a pentyl group. Suitable alkyl groups are lower alkyl groups having 1 to 3 carbon atoms such as a methyl group, an ethyl group, and a propyl group, and particularly preferred is a methyl group.

Examples of the alkyl group in which R ¹ , R ² , R ³ , R ⁴ and R ⁵ contain a fluorine atom (hereinafter sometimes abbreviated as a fluorine atom-containing alkyl group) include a monofluoromethyl group and difluoromethyl. Group, trifluoromethyl group, 1-monofluoroethyl group, 1,1-difluoroethyl group, 1,1,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, 1,1, 2,2,2-pentafluoroethyl group, propyl fluoride group replacing 1-7 fluorine atoms, butyl fluoride group replacing 1-9 fluorine atoms and 1-11 fluorine atoms replaced Pentyl group to be used.

  Among the formulas (3) to (5), an anthryl group represented by the formula (5) is preferable. Of the anthryl groups represented by the formula (5), the 9-methylanthryl group represented by the formula (6) is preferable.

  A suitable compound among the blue light-emitting compounds represented by the above (1) can be represented by the formula (7).

  However, two R in Formula (7) have the same meaning as described above.

  The blue light-emitting compound represented by the formula (1) has a structure in which the fluorene skeleton -Ar- and other aromatic groups -Ar1- and -Ar2- are bonded via a methylene group with the fluorene skeleton -Ar- as the center. It is specific to have In particular, when the aromatic group -Ar1- and / or -Ar2- is an anthryl group, the object of the present invention can be achieved well.

  That is, anthracene itself is a compound that was first discovered as a material capable of electroluminescence (W. Helfrich, W. G. Schneider, Phys. Rev. Lett. 14, 229 (1965)). However, the fluorescence due to anthracene has low luminance and is insufficient as a blue light emitting compound. In contrast, the blue light-emitting compound according to the present invention has an aromatic skeleton represented by an anthracene skeleton and a fluorene skeleton located at the center of the molecule bonded via a methylene bond. When excited, the excited π electrons in the aromatic groups located on both sides of the methylene group swell and the aromatic rings interact spatially with each other. Therefore, the π-electron system is no longer cleaved by a methylene group, but as in the case where no methylene group is present, the π-electron on the fluorene skeleton and the π-electron on the aromatic ring located on both sides of the fluorene skeleton Since there is no specific conjugation, the energy difference between the excited state of the excited π-electrons and the ground state is reduced, and adjustment is made so that blue light can be emitted with high luminance. Furthermore, the aromatic rings on both sides to which the methylene bond is bonded in the blue light-emitting compound of the present invention are not π-electron conjugated, and the emitted light is shifted to the longer wavelength side. Thus, π electrons in the two aromatic rings sandwiching the methylene group interact due to the hyperconjugation effect in the methylene bond. As a result, this blue light-emitting compound is a durable light-emitting compound since it has high emission intensity, exhibits blue light emission with high luminance, and has an aromatic skeleton. On the other hand, if the aromatic ring and the aromatic ring are bonded with a single bond, even if the π-electron system plane is twisted, it shifts to a longer wavelength side than blue light emission, that is, it does not exhibit vivid blue light emission. In addition, the light emission luminance is lowered, and the object of the present invention cannot be achieved.

The blue light-emitting compound represented by the formula (1) is produced by reacting H—Ar—H with CH ₂ X—Ar 1 and / or CH ₂ X—Ar ₂ . Here, -Ar-, -Ar1, and -Ar2 have the same meaning as described above. X represents a halogen atom, particularly a chlorine atom. Further, blue light-emitting compound either -Ar1 and -Ar2 is a hydrogen atom is prepared by reacting H-Ar-CH ₃ and _CH 2 X-Ar1 or _CH 2 X-Ar2.

  In the synthesis of the blue light-emitting compound represented by the formula (1), the reaction proceeds by heating in an appropriate solvent. The heating temperature is usually 60 to 90 ° C. A catalyst such as a metal may be used to accelerate the reaction. The reaction is usually completed in 10 minutes to several hours.

  The blue light-emitting compound according to the present invention emits visible light over a range of 400 to 470 nm as a whole by applying electromagnetic wave energy. For example, it has a fluorescence spectrum as shown in FIG. 9 and can emit blue light. It can utilize for an element, for example, an organic EL element. Furthermore, the light emitting element provided with the light emitting layer containing the red light emitting compound, the green light emitting compound and the blue light emitting compound of the present invention can emit white light.

  The light emitting device according to the present invention will be described below.

  FIG. 1 is an explanatory diagram showing a cross-sectional structure of a light-emitting element that is also a single-layer organic EL element. As shown in FIG. 1, the light emitting element A is formed by laminating a light emitting layer 3 containing a light emitting material and an electrode layer 4 in this order on a substrate 1 on which a transparent electrode 2 is formed.

  The light-emitting element shown in FIG. 1 energizes the transparent electrode 2 and the electrode layer 4 when the light-emitting layer 3 contains the blue light-emitting compound, the red light-emitting compound, and the green light-emitting compound according to the present invention in a balanced manner. Then, it emits white light. Moreover, it can be made to light-emit in a desired color by making the light emitting layer 3 contain the blue light emitting compound, red light emitting compound, and green light emitting compound which concern on this invention in a suitable ratio. For light emission, when an electric field is applied between the transparent electrode 2 and the electrode layer 4, electrons are injected from the electrode layer 4 side, holes are injected from the transparent electrode 2, and electrons are further emitted from the light emitting layer 3. It is a phenomenon in which energy is released as light when recombining with holes and the energy level returns from the conduction band to the valence band.

  When the entire shape of the light emitting element A shown in FIG. 1 is a large area planar shape, the light emitting element A is attached to, for example, a wall surface or a ceiling, and is a surface such as a large area wall surface white light emitting element and a large area ceiling surface white light emitting element. It can be set as a light emitting lighting device. That is, this light emitting element can be used as a surface light source in place of a conventional linear light source such as a fluorescent lamp or a point light source such as a light bulb. In particular, it is possible to emit or illuminate a wall surface, a ceiling surface, or a floor surface of a living room, office room, vehicle room, or the like as a surface light source by the light emitting element. Furthermore, the light emitting element A can be used for backlights such as a display screen in a computer, a display screen in a mobile phone, and a numeric display screen in a cash register. In addition, the light-emitting element A can be used as various light sources such as direct illumination and indirect illumination, and can emit light at night and has good visibility, a road sign device, and It can also be used as a light source such as a light-emitting bulletin board and a brake lamp in a vehicle such as an automobile. Moreover, since the light emitting element A has a blue light emitting compound having a specific chemical structure in the light emitting layer, the light emitting life is long. Therefore, the light emitting element A can be a light source that emits light with a long lifetime.

  Further, when the light emitting layer in the light emitting element A contains the blue light emitting compound according to the present invention and does not contain the red light emitting compound and the green light emitting compound, the light emitting element A emits bright blue light.

  Further, the light-emitting element A is a tubular light-emitting body in which the substrate 1 formed in a cylindrical shape and the transparent electrode 2, the light-emitting layer 3, and the electrode layer 4 are laminated in this order on the inner surface side of the substrate 1. it can. Since this light emitting element A does not use mercury, it can be used as an environmentally friendly light source instead of a conventional fluorescent lamp using mercury.

  As the substrate 1, a known substrate can be adopted as long as the transparent electrode 2 can be formed on the surface thereof. Examples of the substrate 1 include a glass substrate, a plastic sheet, a ceramic, and a metal plate obtained by processing the surface into an insulating property such as forming an insulating coating layer on the surface.

  When the substrate 1 is opaque, the light emitting element containing the red light emitting compound, the green light emitting compound and the blue light emitting compound according to the present invention in the light emitting layer can irradiate white light on the side opposite to the substrate 1. It is a lighting device. Moreover, when this board | substrate 1 is transparent, it is a double-sided illuminating device which can irradiate white light from the board | substrate 1 side of a light emitting element, and the surface on the opposite side.

As the transparent electrode 2, various materials can be employed as long as they have a large work function and are transparent and can act as an anode by applying a voltage to inject holes into the light emitting layer 3. Specifically, the transparent electrode 2 is made of an inorganic transparent conductive material such as ITO, In ₂ O ₃ , SnO ₂ , ZnO, or CdO, or a compound thereof, or a conductive polymer material such as polyaniline. Can do.

  The transparent electrode 2 is formed on the substrate 1 by chemical vapor deposition, spray pyrolysis, vacuum deposition, electron beam deposition, sputtering, ion beam sputtering, ion plating, ion assisted deposition, and others. It can be formed by the method.

  When the substrate is formed of an opaque member, the electrode formed on the substrate does not need to be a transparent electrode.

  The light emitting layer 3 is a layer containing the blue light emitting compound according to the present invention when emitting blue light, and the red light emitting compound, the green light emitting compound and the blue light emitting compound according to the present invention when emitting white light. The light emitting layer 3 can be formed as a polymer film in which the blue light emitting compound according to the present invention, or the red light emitting compound, the green light emitting compound and the blue light emitting compound according to the present invention are dispersed in a polymer. The blue light-emitting compound according to the present invention, or the red light-emitting compound, the green light-emitting compound, and the blue light-emitting compound according to the present invention can be formed as a deposited film formed by vapor deposition on the transparent electrode 2.

  As the polymer in the polymer film, polyvinyl carbazole, poly (3-alkylenethiophene), polyimide containing arylamine, polyfluorine, polyphenylene vinylene, poly-α-methylstyrene, vinylcarbazole / α-methylstyrene copolymer A coalescence etc. can be mentioned. Among these, polyvinyl carbazole is preferable.

  The content of the blue light emitting compound according to the present invention, or the red light emitting compound, the green light emitting compound and the blue light emitting compound according to the present invention in the polymer film is usually 0.01 to 2% by weight, preferably 0.05. ~ 0.5 wt%.

  The thickness of the polymer film is usually 30 to 500 nm, preferably 100 to 300 nm. If the thickness of the polymer film is too thin, the amount of emitted light may be insufficient, and if the thickness of the polymer film is too large, the driving voltage may become too high, which may be undesirable. Flexibility may be lacking when using a curved or annular body.

  The polymer film is coated using a solution obtained by dissolving the polymer and the blue light-emitting compound according to the present invention, or the red light-emitting compound, the green light-emitting compound, and the blue light-emitting compound according to the present invention in an appropriate solvent. For example, it can be formed by a spin casting method, a coating method, a dipping method, or the like.

  When the said light emitting layer 3 is a vapor deposition film, the thickness of the vapor deposition film is generally 0.1-100 nm, although it changes with layer structures in a light emitting layer, etc. When the thickness of the deposited film is too small or too large, the same problem as described above may occur.

  The electrode layer 4 employs a material having a small work function, and may be formed of a single metal or a metal alloy such as MgAg, an aluminum alloy, and metal calcium. A preferred electrode layer 4 is an alloy electrode of aluminum and a small amount of lithium. The electrode layer 4 can be easily formed on the surface including the light emitting layer 3 formed on the substrate 1, for example, by a vapor deposition technique.

  Regardless of which of the coating method and the vapor deposition method is employed, it is preferable to interpose a buffer layer between the electrode layer and the light emitting layer.

  Examples of a material that can form the buffer layer include alkali metal compounds such as lithium fluoride, alkaline earth metal compounds such as magnesium fluoride, oxides such as aluminum oxide, 4,4′-biscarbazole biphenyl ( Cz-TPD). Further, as a material for forming a buffer layer formed between an anode such as ITO and an organic layer, for example, m-MTDATA (4,4 ′, 4 ″ -tris (3-methylphenylphenylamino) triphenyl Amine), phthalocyanine, polyaniline, polythiophene derivatives, inorganic oxides such as molybdenum oxide, ruthenium oxide, vanadium oxide, and lithium fluoride. By appropriately selecting the material of these buffer layers, the driving voltage of the organic EL element, which is a light emitting element, can be reduced, the quantum efficiency of light emission can be improved, and the emission luminance can be improved. can do.

  Next, the 2nd example of the light emitting element which concerns on this invention is shown in a figure. FIG. 2 is an explanatory view showing a cross section of a light-emitting element which is a multilayer organic EL element.

  As shown in FIG. 2, the light-emitting element B is formed by laminating a transparent electrode 2, a hole transport layer 5, light-emitting layers 3a and 3b, an electron transport layer 6 and an electrode layer 4 in this order on the surface of a substrate 1.

  The substrate 1, the transparent electrode 2, and the electrode layer 4 are the same as those in the light emitting element A shown in FIG.

  The light emitting layer in the light emitting element B shown in FIG. 2 includes a light emitting layer 3a and a light emitting layer 3b. The light emitting layer 3b is a DPVBi layer. This DPVBi layer is a layer having a host material function.

  Examples of the hole transport material contained in the hole transport layer 5 include triphenylamine compounds such as N, N′-diphenyl-N, N′-di (m-tolyl) -benzidine (TPD) and α-NPD. Examples thereof include hydrazone compounds, stilbene compounds, heterocyclic compounds, and π electron starburst hole transport materials.

  Examples of the electron transport material contained in the electron transport layer 6 include 2- (4-tert-butylphenyl) -5- (4-biphenyl) -1,3,4-oxaxene. Oxadiazole derivatives such as diazole and 2,5-bis (1-naphthyl) -1,3,4-oxadiazole, and 2,5-bis (5′-tert-butyl-2′-benzoxazolyl) thiophene Etc. As the electron transporting substance, for example, a metal complex material such as a quinolinol aluminum complex (Alq3) or a benzoquinolinol beryllium complex (Bebq2) can be preferably used.

  In the light emitting element B in FIG. 2, the electron transport layer 6 contains Alq3.

  The thickness of each layer is the same as that in a conventionally known multilayer organic EL element.

  The light emitting element B shown in FIG. 2 operates in the same manner as the light emitting element A shown in FIG. 1 and emits light. Therefore, the light-emitting element B shown in FIG. 2 has the same application as the light-emitting element A shown in FIG.

  FIG. 3 shows a third example of the light emitting device according to the present invention. FIG. 3 is an explanatory view showing a cross section of a light emitting device which is a multilayer organic EL device.

  The light-emitting element C shown in FIG. 3 is formed by laminating a transparent electrode 2, a hole transport layer 5, a light-emitting layer 3, an electron transport layer 8 and an electrode layer 4 in this order on the surface of a substrate 1.

  The light emitting element C shown in FIG. 3 is the same as the light emitting element B.

  FIG. 4 shows another example of the light emitting element. The light emitting element D shown in FIG. 4 is formed by laminating a substrate 1, an electrode 2, a hole transport layer 5, a light emitting layer 3 and an electrode layer 4 in this order.

  In addition to the light emitting device shown in FIGS. 1 to 4, a hole transport layer containing a hole transport material between an anode that is a transparent electrode and a cathode that is an electrode layer formed on a substrate, and the present invention A two-layer organic low-molecular light-emitting device comprising a blue light-emitting compound-containing electron transporting light-emitting layer according to the present invention (for example, a hole transport layer between an anode and a cathode, and a blue color according to the present invention as a guest dye) A two-layer dye-doped light-emitting device in which a light-emitting compound and a light-emitting layer containing a host dye are laminated, a hole transport layer containing a hole-transporting substance between the anode and the cathode, and the blue color in the present invention A two-layer organic light-emitting device obtained by laminating an electron-transporting light-emitting layer obtained by co-evaporation of a light-emitting compound and an electron-transporting material (for example, a hole transport layer and a guest dye between an anode and a cathode) Blue light emitting compound according to the present invention A two-layer dye-doped organic light-emitting device comprising an electron-transporting light-emitting layer containing a host dye and a host dye), a hole-transporting layer between the anode and the cathode, and the blue light-emitting compound-containing material according to the present invention A three-layer organic light-emitting device formed by laminating a light-emitting layer and an electron transport layer can be given.

  The electron-transporting light-emitting layer in this light-emitting device is usually 50 to 80% polyvinyl carbazole (PVK), 5 to 40% of an electron-transporting light-emitting agent, and the blue light-emitting compound according to the present invention 0.01 to 20 When formed with% (weight), blue light emission occurs with high luminance.

  The light emitting layer preferably contains rubrene as a sensitizer, and particularly preferably contains rubrene and Alq3.

  The blue light-emitting element using the blue light-emitting compound according to the present invention, or the red light-emitting compound, the green light-emitting compound, and the white light-emitting element using the blue light-emitting compound according to the present invention are generally used as, for example, a DC drive type organic EL element. It can also be used as a pulse-driven organic EL element and an AC-driven organic EL element.

Example 1
In this example, a blue light-emitting compound having a structure represented by the formula (8) was produced as follows.

  A 1.5-liter three-necked flask was charged with 50 g of 9,9-dimethylfluorene, 40 g of paraformaldehyde, 375 ml of acetic acid and 387 ml of concentrated hydrochloric acid (36%), and further 308 g of polyphosphoric acid was added. The reaction was started by heating the interior of the flask to 115 ° C. while blowing hydrogen chloride gas into the liquid in the flask. Blowing hydrogen chloride gas and heating at 115 ° C. were continued for 7 hours. After 7 hours, heating was stopped and the mixture was allowed to cool to return the reaction product solution in the flask to room temperature. The crystals formed by concentrating the reaction product at room temperature are filtered off, and the separated crystals are purified by recrystallization from methanol and cyclohexane to obtain 2,7-dichloromethyl-9,9-dimethylfluorene. It was.

  The IR spectrum chart and NMR spectrum chart of this di-2,7-chloromethyl-9,9-dimethylfluorene are shown in FIGS. 5 and 6, respectively.

  The 2,7-dichloromethyl-9,9-dimethylfluorene (7.0 g), 9-methylanthracene (10.0 g), zinc powder (2.4 g), and carbon disulfide (200 ml) were charged into a 500 ml three-necked flask. The reaction was carried out for 8 hours while heating to 50 ° C. After completion of the reaction, the reaction product solution in the flask was concentrated, the produced crystals were filtered off, and the crystals were recrystallized from toluene and purified by sublimation. The IR spectrum chart of the purified crystal is shown in FIG. 7, and the NMR spectrum chart is shown in FIG.

  A sample solution was prepared by dissolving the blue light-emitting compound of the purified crystal represented by the formula (8) in toluene to a concentration of 1 mg / L. This sample solution was loaded into an F-4500 type spectrofluorometer manufactured by Shimadzu Corporation, and the fluorescence spectrum was measured under the following conditions. The obtained fluorescence spectrum is shown in FIG.

Measurement conditions Measurement mode Wavelength scan Excitation wavelength 365nm
Fluorescence start wavelength 365nm
Fluorescence end wavelength 720nm
Scanning speed 2400 nm / min Excitation side slit 5.0 nm
Fluorescent side slit 5.0nm
Photomultiplier voltage 700V

FIG. 1 is an explanatory view showing a light emitting element as an example according to the present invention. FIG. 2 is an explanatory view showing a light emitting device as another example according to the present invention. FIG. 3 is an explanatory view showing a light emitting device as another example according to the present invention. FIG. 4 is an explanatory view showing a light emitting device as still another example according to the present invention. FIG. 5 is an IR spectrum chart showing 2,7-dichloromethyl-9,9-dimethylfluorene synthesized in the example of the present invention. FIG. 6 is an NMR spectrum chart showing 2,7-dichloromethyl-9,9-dimethylfluorene synthesized in the example of the present invention. FIG. 7 is an IR spectrum chart showing the blue light-emitting compound represented by the formula (8) synthesized in the example of the present invention. FIG. 8 is an NMR spectrum chart showing the blue light-emitting compound represented by the formula (8) synthesized in the example of the present invention. FIG. 9 is a fluorescence spectrum chart showing the fluorescence spectrum of the blue light-emitting compound represented by the formula (8) synthesized in the example of the present invention.

Explanation of symbols

1, 1a, 1b ... light emitting display device, 1c ... full color image display device, 2 ... transparent member, 3, 3a, 3b ... light emitting layer, 3br ... red light emitting layer, 3bg ... Green light emitting layer, 3bb ... blue light emitting compound, 4 ... light emitting element, 5 ... light guide member, 6 ... optical shutter

Claims (3)

A blue light-emitting compound having a structure represented by the following formula (1):

(However, in Formula (1), -Ar- is a fluorene skeleton represented by Formula (2), Ar1- and Ar2- are aromatic substituents, and they are the same or different from each other. Is also good.)

(However, in the formula (2), two Rs each represent an alkyl group having 1 to 12 carbon atoms, and the two Rs may be the same or different.) The blue light-emitting compound according to claim 1, wherein Ar1 and Ar2 are aromatic substituents represented by any of the following formulas (3) to (5).

(However, in the formula, R ¹ represents an alkyl group that may be substituted by a fluorine atom having 1 to 5 carbon atoms. M represents an integer of 0 or ¹ to 5. A plurality of R ¹ may be the same. R ² represents an alkyl group which may be substituted by a fluorine atom having 1 to 5 carbon atoms, n represents an integer of 0 or 1 to 3. A plurality of R ² are the same. R ³ represents an alkyl group which may be substituted by a fluorine atom having 1 to 5 carbon atoms, p represents an integer of 0 or 1 to 4. A plurality of R ³ are the same. In addition, R ² and R ³ may be the same or different, and R ⁴ is an alkyl that may be substituted by a fluorine atom having 1 to 5 carbon atoms. a group .R ⁵ is .q showing an alkyl group which may be substituted with fluorine atoms of 1 to 5 carbon atoms, an integer Codes 0 to 3.. multiple ^{R 5} It is the same or may be different also. In addition, it may be different even with the same R ⁴ and R ^5.) A light emitting element comprising a light emitting layer containing a blue light emitting compound represented by the general formula (1) provided between a pair of electrodes.

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