JP6811548B2 - Torquesen derivatives and organic electroluminescent devices - Google Patents

Description

The present invention relates to Torquesen derivatives and organic electroluminescent devices.

In recent years, the development of an organic electroluminescence display (Organic Electroluminescence Display) has been promoted. Further, an organic electroluminescence device (Organic Electroluminescence Device), which is a self-luminous light emitting element used in an organic electroluminescence display device, has been actively developed.

As a structure of the organic electroluminescent device, for example, a structure in which an anode, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and a cathode are laminated in this order is known. In such an organic electroluminescent device, first, holes and electrons injected from the anode and the cathode recombine in the light emitting layer to generate excitons, and then the generated excitons are brought into the basal state. The transition causes light emission.

Here, in order to improve the performance of the organic electroluminescent device, various compounds are being studied as materials for each layer. For example, Patent Documents 1 to 3 disclose Torxene derivatives that can be used as constituent materials for each layer of an organic electroluminescent device.

International Publication No. 2006/005626 Japanese Unexamined Patent Publication No. 2006-135146 Japanese Unexamined Patent Publication No. 2003-261473

However, the Torquesen derivatives disclosed in Patent Documents 1 to 3 did not have sufficient film-forming property when forming a layer by a coating method. If the film forming property when forming the layer is insufficient, the surface of the layer becomes uneven and the layer thickness becomes non-uniform, which causes various problems, for example, the applied electric field becomes non-uniform. As a result, electric leakage and uneven light emission may occur.

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is a Torxen derivative having excellent film forming property when forming a layer, and an organic electroluminescent device containing the Torxen derivative. Is to provide.

In order to solve the above problems, according to a certain viewpoint of the present invention, a Torquesen derivative represented by the following general formula (1) is provided.
In the above general formula (1)
R _{1 to} R ₆ are independent of each other, hydrogen atoms, linear, branched or cyclic alkyl groups having 1 to 16 substituted or unsubstituted carbon atoms, and substituted or unsubstituted carbon atoms 1 to 16. A linear or branched alkoxy group, an aryl group having a substituted or unsubstituted ring-forming carbon number of 6 to 36, or a heterocyclyl group having a substituted or unsubstituted ring-forming carbon number of 3 to 32.
X ₁ is a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothienyl group, a substituted or unsubstituted carbazolyl group or a substituted or unsubstituted fluorenyl group.
X ₂ and X ₃ are independent of each other with a hydrogen atom, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothienyl group, a substituted or unsubstituted carbazolyl group or a substituted or unsubstituted fluorenyl group. is there.

From this point of view, it is possible to provide a Torxen derivative having excellent film forming property when forming a layer.

X ₁ , X ₂ and X ₃ may be the same group.

From this point of view, the film-forming property of the Torquesen derivative can be further improved, and the production of the Torquesen derivative becomes relatively easy.

X ₁ , X ₂ and X ₃ are independently substituted or unsubstituted dibenzofuranyl groups, substituted or unsubstituted dibenzothienyl groups, substituted or unsubstituted carbazolyl groups or substituted or unsubstituted fluorenyl groups. Yes, and X ₁ , X ₂ and X ₃ may each be attached to the Torxen skeleton at its benzene ring site.

From this point of view, a conjugated system is formed between the Torxen skeleton in the Torxen derivative and X ₁ , X ₂ and X _3, and the electron donating ability of the Torxen derivative becomes high.

R _{1 to} R ₆ are independent of each other, hydrogen atoms, linear, branched or cyclic alkyl groups having 1 to 7 substituted or unsubstituted carbon atoms, and substituted or unsubstituted carbon atoms 1 to 7. It may be a linear or branched alkoxy group, or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms.

From this point of view, the film-forming property of the Torquesen derivative can be further improved.

R _{1 to} R ₆ may be a linear alkyl group, a phenyl group or an alkylphenyl group having 1 to 7 carbon atoms independently of each other.

From this point of view, the film-forming property of the Torquesen derivative can be further improved.

Further, in order to solve the above-mentioned problems, according to another aspect of the present invention, an organic electroluminescent device containing the above-mentioned Torquesen derivative is provided.

From this point of view, since the layer containing the Torquesen derivative in the organic electroluminescent device has less surface irregularities, a problem caused by the non-uniformity of each layer of the organic electroluminescent device, for example, the applied electric field is It is possible to prevent electroluminescence and uneven light emission due to non-uniformity.

The organic electroluminescent device has a light emitting layer, a hole transport layer and / or a hole injection layer, and the light emitting layer, the hole transport layer and / or the hole injection layer contains the Torxen derivative. You may.

From this point of view, for example, it is possible to prevent electric leakage and uneven light emission due to non-uniform application of the electric field, and to use the input power for light emission without waste. As a result, the light emission of the organic electroluminescent element The efficiency can be relatively high.

As described above, according to the present invention, it is possible to provide a Torxen derivative having excellent film forming property when forming a layer, and an organic electroluminescent device containing the Torxen derivative.

It is a schematic diagram which shows an example of the organic electroluminescent element which concerns on one Embodiment of this invention. It is a schematic diagram which shows an example of the organic electroluminescent element which concerns on other embodiment of this invention.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the present specification and the drawings, components having substantially the same functional configuration are designated by the same reference numerals, so that duplicate description will be omitted.

<1. Torquesen derivative>
First, the Torquesen derivative according to the embodiment of the present invention will be described. The Torquesen derivative according to this embodiment is a compound represented by the following general formula (1).

In the above general formula (1)
R _{1 to} R ₆ are independent of each other, hydrogen atoms, linear, branched or cyclic alkyl groups having 1 to 16 substituted or unsubstituted carbon atoms, and substituted or unsubstituted carbon atoms 1 to 16. A linear or branched alkoxy group, an aryl group having a substituted or unsubstituted ring-forming carbon number of 6 to 36, or a heterocyclyl group having a substituted or unsubstituted ring-forming carbon number of 3 to 32.

X ₁ is a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothienyl group, a substituted or unsubstituted Carbazolyl group or a substituted or unsubstituted fluorenyl group. Is.

X ₂ and X ₃ are independent of each other, a hydrogen atom, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothienyl group, and a substituted or unsubstituted Carbazolyl group. Alternatively, it is a substituted or unsubstituted fluorenyl group.

The Torquesen derivative according to this embodiment has an amorphous structure in the film to be formed. Therefore, the Torquesen derivative according to the present embodiment is excellent in film forming property when forming a layer by a coating method or the like, and it is possible to form a film having less unevenness on the surface. Therefore, it is possible to prevent problems caused by the non-uniformity of each layer of the organic electroluminescent element, for example, electric leakage and uneven light emission due to the non-uniformity of the applied electric field.

Further, since the Torquesen derivative according to the present embodiment has an amorphous structure in the film to be formed, the film to be formed has flexibility and is excellent in followability to a substrate or the like. Therefore, Torquesen derivatives are suitable for use in flexible organic electroluminescent devices.

Further, as represented by the general formula (1), the Torquesen derivative according to the present embodiment has a specific benzoheterole ring such as a dibenzofuranyl group or a fluoreneyl group bonded to the Torquesen skeleton. There is. In general, compounds having a Torxen skeleton have hole transporting ability and / or hole injecting ability, but such groups give the Torxen derivative an appropriate electron donating ability, and as a result, the Torxen derivative is bipolar. Has. When such a Torxen derivative is used in an organic electroluminescent device, the charge balance between holes and electrons in the device is appropriately adjusted, and the luminous efficiency of the organic electroluminescent device becomes excellent.

Further, since X _{1 to} X ₃ are bonded to a predetermined position on the Torquesen skeleton, the degree of steric congestion in the Torquesen derivative is relatively low, and as a result, the Torquesen derivative is chemically stable. It will be a derivative.

The Torquesen derivative according to the present embodiment is particularly suitable for use as a host material, a hole transport material, and a hole injection material for a light emitting layer in an organic electroluminescent device.

The carbon number of the linear, branched or cyclic alkyl group in R _{1 to} R ₆ in the above general formula (1) may be within the above range, but is preferably 1 to 12, and more. It is preferably 1 to 7. In particular, the number of carbon atoms of the linear or branched alkyl group is preferably 1 to 6, and more preferably 1 to 4. In particular, the number of carbon atoms of the cyclic alkyl group may be within the above range, but is preferably 3 to 7, and more preferably 4 to 7. Further, among the linear, branched or cyclic alkyl groups, a linear or branched alkyl group is preferable, and a linear alkyl group is more preferable.

The linear, branched or cyclic alkyl group in R _{1 to} R ₆ is not particularly limited, and is, for example, a methyl (methyl) group, an ethyl (ethyl) group, a propyl (propyl) group, and a butyl (butyl) group. ) Group, octyl group, decyl group, pentadecyl group and other linear alkyl groups, and t-butyl group and other branched alkyl groups, cyclobutyl group, cyclopentyl ) Group, cycloalkyl group, cycloalkyl group such as cycloheptyl group, and the like.

The number of carbon atoms of the linear or branched alkoxy group in R _{1 to} R ₆ may be within the above range, but is preferably 1 to 12, more preferably 1 to 7, and even more preferably. Is 1 to 6, and even more preferably 1 to 4. Further, among the linear or branched alkoxy groups, a linear alkoxy group is preferable. The alkoxy group is not particularly limited, and is, for example, a methoxy (methoxy) group, an ethoxy (ethoxy) group, a propoxy group, a butoxy group, an octyloxy group, and a decyloxy group. Examples thereof include a linear alkoxy group such as a group, a pentadecyloxy group, and a branched alkoxy group such as a t-butoxy group.

The number of ring-forming carbon atoms of the aryl group may be within the above range, but is preferably 6 to 18, more preferably 6 to 12, and even more preferably 4 to 7. Examples of the aryl group include a monocyclic aromatic group such as a phenyl group, a biphenyl group, a terphenyl group, a fluoroanthenyl group, and a triphenylenyl group. Non-condensed polycyclic aromatic group, naphthyl group, anthryl group, phenanthryl group, fluorenyl group, indenyl group, pyrenyl group, acetnaphthenyl group. Examples thereof include a fused polycyclic aromatic group such as a group.

The number of ring-forming carbon atoms of the heterocyclyl group may be within the above range, but is preferably 4 to 18, and more preferably 5 to 12. Examples of the heterocyclyl group include a heteroaryl group and a non-aromatic heterocyclyl group.

As the heteroaryl group, for example, a monocyclic heteroaryl group such as a pyridyl group, a furanyl group, a pyranyl group, a thienyl group, a quinolyl group and an isoquinolyl group. Group, benzofuranyl group, benzothienyl group, indolyl group, carbazolyl group, benzoxazolyl group, benzothiazolyl group, benzothiazolyl group, benzothiazolyl group, benzothiazolyl group, benzothiazolyl group. Polycyclic heteroaryl groups such as (benzimidazolyl) group, pyrazolyl group, dibenzofuranyl group, and dibenzothienyl group can be mentioned.

Examples of the non-aromatic heterocyclyl group include pyrrolidinyl group, tetrahydrofuranyl group, tetrahydrothiophenyl group, tetrahydropyranylpyranylpyranyl group, tetrahydropyranyl group, tetrahydropyranyl group, tetrahydropyranyl group, and tetrahydropyranyl group. (Piperidinyl) group, 1,4-dioxanyl group, 1,4-oxathianyl group, morpholinyl group, 1,4-dithianyl group, piperazinyl group, 1,4 − Azathianyl group and the like can be mentioned.

R _{1 to} R ₆ may be as described above, but independently of each other, a hydrogen atom, a substituted or unsubstituted linear, branched or cyclic alkyl group having 1 to 7 carbon atoms, and a substituted moiety. Alternatively, it is preferably a linear or branched alkoxy group having 1 to 7 unsubstituted carbon atoms, or an aryl group having 6 to 12 substituted or unsubstituted ring-forming carbon atoms, and having 1 to 7 carbon atoms. It is more preferably a linear alkyl group, phenyl group or alkylphenyl group, and even more preferably a methyl group, an ethyl group, an n-propyl group, a phenyl group or a methylphenyl group.

X ₂ and X ₃ may be any group defined in the above general formula (1), but preferably a substituted or unsubstituted dibenzofuranyl group or a substituted or unsubstituted dibenzothienyl group independently of each other. , Substituted or unsubstituted carbazolyl group or substituted or unsubstituted fluorenyl group. As a result, the electron donating ability of the Torquesen derivative can be made sufficient. In particular, when the Torquesen derivative is contained in the light emitting layer, not only the hole injection property into the light emitting layer but also the electron injection property can be made excellent.

Further, in this case, X _{1 to} X ₃ are any one, preferably two, and more preferably all of them bonded to the Torxen skeleton at the benzene ring site. As a result, a conjugated system is formed between the Torxen skeleton in the Torxen derivative and X _{1 to} X _3, and the electron donating ability of the Torxen derivative becomes high.

More specifically, in the above case, X _{1 to} X ₃ are substituted or unsubstituted dibenzofuran-1-, -2-, -3- or -4-yl, substituted or unsubstituted dibenzothiophene-1- , -2-, -3- or -4-yl, substituted or unsubstituted carbazole-1-, -2-, -3- or -4-yl, or substituted or unsubstituted fluoren-1-, -2 -, -3- or -4-yl. X _{1 to} X ₃ are preferably substituted or unsubstituted dibenzofuran-2- or -4-yl, substituted or unsubstituted dibenzothiophene-2- or -4-yl, substituted or unsubstituted carbazole-3-3. Il or substituted or unsubstituted fluorene-2- or -4-yl.

Further, X _{1 to} X ₃ do not have to be bonded to the Torquesen skeleton at the benzene ring site. Specifically, X _{1 to} X ₃ may be substituted or unsubstituted carbazole-9-yl or substituted or unsubstituted fluorene-9-yl.

X _{1 to} X ₃ may be different from each other, but it is preferable that any two or more of them are the same group, and it is more preferable that all of them are the same group. This stabilizes the structure of the Torquesen derivative and makes it relatively easy and convenient to manufacture the Torquesen derivative.

The substituent substitutable in each group of X _{1 to} X ₃ and R _{1 to} R ₆ is not particularly limited, but for example, a cyano group, a silyl group, and a mono having 1 to 10 carbon atoms. (Mono-), di- or tri-alkylsilyl group, linear, branched or cyclic alkyl (alkyl) group with 1 to 16 carbon atoms, 1 to 16 carbon atoms Examples thereof include a linear or branched alkoxy group, an aryl group having 6 to 36 ring-forming carbon atoms, and a heterocyclyl group having 3 to 32 ring-forming carbon atoms. In each group of X _{1 to} X ₃ and R _{1 to} R ₆ , the above-mentioned substituent is substituted with a hydrogen atom in X _{1 to} X ₃ and R _{1 to} R ₆ in the case of no substitution. When two or more hydrogen atoms are substituted in each of the groups X _{1 to} X ₃ and R _{1 to} R ₆ , the cyclic alkyl group and the aryl group include the substituent and the atom to which the substituent is bonded. And / or heterocyclyl groups may be formed. Further, in this case, the substituent may form a structure that condenses with the Torxen skeleton.

The specific examples of each substituent, the preferable number of carbon atoms, and the like are not particularly limited, but can be the same as those of the above-mentioned groups R _{1 to} R ₆ . In particular, the substituents of X _{1 to} X ₃ are linear or branched alkyl groups having 1 to 6 carbon atoms or aryls having 4 to 18 ring-forming carbon atoms, which are independent of each other for each substituent. is preferably a (aryl) group, a methyl group, an ethyl group, a propyl group, more preferably a t- butyl group, a fused benzene ring formed together with benzene ring of phenyl group or X ₁ to X _3, methyl It is more preferably a group or a phenyl group.
Further, the substituent may be substituted at any site of each group of X _{1 to} X ₃ and R _{1 to} R ₆ .

Here, the structural formulas of compounds 1 to 29, which are specific examples of the Torquesen derivative according to the present embodiment described above, are shown below. Further, among the compounds 1 to 29 shown below, compounds 1, 18, 22, and 24 are particularly preferable. However, the Torquesen derivative according to this embodiment is not limited to the following compounds.

The Torquesen derivative according to the present embodiment has been described in detail above. Since the Torquesen derivative according to the present embodiment has an amorphous structure in the film to be formed, it is excellent in film forming property and can form a film having less surface irregularities. Further, the formed film has flexibility and is excellent in followability to a substrate or the like. Further, the Torquesen derivative according to the present embodiment has an appropriate bipolar property and is excellent in hole injection ability and hole transport ability. Therefore, by using the Torxen derivative according to the present embodiment as a hole transport material, a hole injection material, and / or a host material for the light emitting layer, the charge balance in the organic electroluminescent device can be suitably adjusted, and the organic electroluminescent device can be used. The emission efficiency of the light can be improved.

The method for producing the Torquesen derivative according to the present embodiment is not particularly limited, and the derivative can be produced by a known method or the like.

<2. Organic electroluminescent device>
Next, the organic electroluminescent device using the Torquesen derivative according to the present embodiment will be described in detail with reference to FIG. FIG. 1 is a schematic view showing an example of an organic electroluminescent device according to the present embodiment.

As shown in FIG. 1, the organic electroluminescent element 100 according to the present embodiment includes a substrate 110, a first electrode 120 arranged on the substrate 110, and a hole injection layer 130 arranged on the first electrode 120. The hole transport layer 140 arranged on the hole injection layer 130, the light emitting layer 150 arranged on the hole transport layer 140, the electron transport layer 160 arranged on the light emitting layer 150, and the electron transport. It includes an electron injection layer 170 arranged on the layer 160 and a second electrode 180 arranged on the electron injection layer 170.

The Torxen derivative according to this embodiment may be contained in, for example, the hole injection layer 130, the hole transport layer 140 and / or the light emitting layer 150. As a result, the layer containing the Torquesen derivative becomes flat and uniform. Therefore, for example, it is possible to prevent electric leakage and uneven light emission due to non-uniformity of the applied electric field, and it is possible to use the input power for light emission without waste. As a result, the luminous efficiency of the organic electroluminescent element 100 is compared. It can be highly targeted. Preferably, the Torquesen derivative according to this embodiment is contained in the light emitting layer 150. However, the layer containing the Torquesen derivative according to the present embodiment is not limited to the above. For example, the Torquesen derivative according to the present embodiment may be contained in any of the organic layers between the first electrode 120 and the second electrode 180.

As the substrate 110, a substrate used in a general organic electroluminescent element can be used. For example, the substrate 110 may be a glass substrate, a semiconductor substrate, a transparent plastic substrate, or the like.

The first electrode 120 is formed on the substrate 110. The first electrode 120 is, for example, an anode, and is formed as a transmission type electrode by a metal, an alloy, a conductive compound, or the like having a large work function. Specifically, the first electrode 120 is a transparent, indium tin oxide with excellent conductivity _{(In 2 O 3 -SnO 2:} ITO), indium zinc (In ₂ O ₃ -ZnO) oxide, tin oxide (SnO ₂ ), zinc oxide (ZnO) or the like may be formed. Further, the first electrode 120 may be formed as a reflective electrode in which magnesium (Mg), aluminum (Al), or the like is laminated on the transparent conductive film.

A hole injection layer 130 is formed on the first electrode 120. The hole injection layer 130 is a layer having a function of facilitating the injection of holes from the first electrode 120, and is formed, for example, with a thickness of about 10 nm to about 150 nm.

Here, the hole injection layer 130 may be formed of the Torxen derivative according to the present embodiment. When the Torxen derivative according to the present embodiment is contained in another layer, the hole injection layer 130 is formed of, for example, a compound represented by the following structural formula, a known hole transport material, or the like. May be good.

Known hole injection materials capable of forming the hole injection layer 130 include, for example, triphenylamine-containing polyether ketone (TPAPEK) and 4-isopropyl-4'-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate. (PPBI), N, N'-diphenyl-N, N'-bis- [4- (phenyl-m-trill-amino) -phenyl] -biphenyl-4,4'-diamine (DNTPD), copper phthalocyanine (copper) Phthalocyanin compounds such as phhalocyanine), 4,4', 4 "-tris (3-methylphenylphenylamino) triphenylamine (m-MTDATA), N, N'-di (1-naphthyl) -N, N'- Diphenylbenzidine (NPB), 4,4', 4 "-tris {N, N diphenylamino} triphenylamine (TDATA), 4,4', 4" -tris (N, N-2-naphthylphenylamino) tri Phenylamine (2-TNATA), polyaniline / dodecylbenzenesulfonic acid (Pani / DBSA), poly (3,4-ethylenedioxythiophene) / poly (4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (Pani / CSA), polyaniline / poly (4-styrene sulfonate) (PANI / PSS) and the like.

A hole transport layer 140 is formed on the hole injection layer 130. The hole transport layer 140 is a layer having a function of transporting holes, and is formed, for example, with a thickness of about 10 nm to about 150 nm. The hole transport layer 140 may be formed of a plurality of layers.

Here, the hole transport layer 140 may be formed by including the Torxen derivative according to the present embodiment. Further, when the Torxen derivative according to the present embodiment is contained in another layer, the hole transport layer 140 may be formed of a known hole transport material. Known hole transporting materials include, for example, carbazole derivatives such as 1,1-bis [(di-4-tolylamino) phenyl] cyclohexane (TAPC), N-phenylcarbazole (N-phenylcarbazole), and polyvinylcarbazole (polyvinylcarbazole). , N, N'-bis (3-methylphenyl) -N, N'-diphenyl- [1,1-biphenyl] -4,4'-diamine (TPD), 4,4', 4 "-tris (N) -Carbazolyl) Triphenylamine (TCTA), N, N'-di (1-naphthyl) -N, N'-diphenylbenzidine (NPB) and the like can be mentioned.

A light emitting layer 150 is formed on the hole transport layer 140. The light emitting layer 150 is a layer that emits light by fluorescence, phosphorescence, or the like, and is formed, for example, with a thickness of about 10 nm to about 60 nm. The light emitting layer 150 may be formed as, for example, a mixed layer of a dopant material and a host material. Specifically, the light emitting layer 150 may be formed as a mixed layer in which the dopant material is doped with 0.1 to 50% by mass, preferably 0.1 to 20% by mass, based on the total mass of the host material.

As the host material and the dopant material contained in the light emitting layer 150, any known host material and dopant material can be used. For example, the light emitting layer 150 may contain a fluoranthene derivative, pyrene (and its derivative), an arylacetylene derivative, a fluorene derivative, perylene (and its derivative), a chrysene derivative, a styryl derivative and the like as a host material or a dopant material. More specifically, the light emitting layer 150 is composed of tris (8-quinolinolato) aluminum (Alq3), 4,4'-N, N'-dicabazole-biphenyl (CBP), poly (n-vinylcarbazole) (PVK), and the like. 4,4', 4 "-tris (N-carbazolyl) triphenylamine (TCTA), 1,3,5-tris (N-phenylbenzimidazol-2-yl) benzene (TPBI), 3-tert-butyl- 9,10-di (naphth-2-yl) anthracene (TBADN), distyrylarylene (DSA), 4,4'-bis (9-carbazole) -2,2'-dimethyl-biphenyl (dmCBP), bis ( 2,2-Diphenylvinyl) -1,1'-biphenyl (DPVBi), 1,4-bis (2- (3-N-ethylcarbazolyl) vinyl) benzene (BCzVB), 4- (di-p- Trillamino) -4'-((di-p-tolylamino) styryl) Stilben (DPAVB), N-(4-((E) -2- (6-((E) -4- (diphenylamino) styryl) naphthalene) -2-yl) vinyl) phenyl) -N-phenylbenzeneamine (N-BDAVBi), 2,5,8,11-tetra-t-butylperylene (TBPe), 1,1-dipyrene (1,1-dipyrene) ), 1,4-Dipyrenylbenzene (1,4-dipyrenylbene), 1,4-bis (N, N-diphenylamino) pyrene (1,4-bis (N, N-diphenyllamino) pyrene), etc. It may be included as a material or a dopant material.

Further, the light emitting layer 150 may be formed as a layer that emits light of a specific color. For example, the light emitting layer 150 may be formed as a red light emitting layer, a green light emitting layer, or a blue light emitting layer.

When the light emitting layer 150 is a blue light emitting layer, a known blue dopant can be used. For example, as the blue dopant, perylene and its derivatives, iridium (Ir) complexes such as bis [2- (4,6-difluorophenyl) pyridinate] picolinate iridium (III) (FIrpic), etc. can be used. it can.

Further, when the light emitting layer 150 is a red light emitting layer, a known red dopant can be used. For example, as red dopants, rubrene and its derivatives, 4-dicyanomethylene-2- (p-dimethylaminostyryl) -6-methyl-4H-pyran (DCM) and its derivatives, bis (1-phenylisoquinoline). Iridium complexes such as (acetylacetone) iridium (III) (Ir (piq) ₂ (acac)), osmium (Os) complexes, platinum complexes and the like can be used.

Further, when the light emitting layer 150 is a green light emitting layer, a known green dopant can be used. For example, coumarin and its derivatives, Tris [2- (para-tolyl) pyridine] iridium (Tris [2- (p-tool) pyridine] iridium (III), Ir (mppy) ₃ ), Tris (2- An iridium complex such as phenylpyridine) iridium (III) ((Ir (ppy) ₃ )) can be used.

Further, the host material may contain the Torquesen derivative according to the present embodiment. Further, when the Torquesen derivative according to the present embodiment is contained in another layer, the host material may be formed by a known host.

The host material may be a mixture of two or more compounds. For example, in order to adjust the charge balance of the organic electroluminescent device 100, the host material can include a compound having an electron transporting ability or a hole transporting ability in addition to the compound which is the main component of the host material.

More specifically, when the light emitting layer 150 contains the Torquesen derivative according to the present embodiment as the main component of the host material, a compound having an electron transporting ability may be further contained as the host material. As a result, the charge balance of the organic electroluminescent element 100 is further adjusted, and the luminous efficiency is improved. The compound having such an electron transporting ability is not particularly limited, and is selected from, for example, the compound that can be used as the host material described above and the electron transporting material described later. Preferred examples of the compound having an electron transporting ability that can be used as a host material include, but are not limited to, a quinolinol derivative, an imidazole derivative, and a pyridine derivative, and more specifically, tris (8-quinolinolato) aluminum (Alq3). ), 1,3,5-Tris (N-phenylbenzimidazol-2-yl) benzene (TPBI), 1,3-bis [2- (2,2'-bipyridin-6-yl) -1,3, Examples thereof include 4-oxadiazo-5-yl] benzene, 3,3', 5,5'-tetra [(m-pyridyl) -phenyl-3-yl] biphenyl and the like.

Further, in such a case, the host material is a mixture of the Torquesen derivative and the compound having an electron transporting ability according to the present embodiment in a mass ratio of the Torquesen derivative: the compound having an electron transporting ability = 20: 1 to 1: 4. It is preferably contained in a ratio of 10: 1 to 1: 1.

An electron transport layer 160 is formed on the light emitting layer 150. The electron transport layer 160 is a layer having a function of transporting electrons, and is formed, for example, with a thickness of about 15 nm to about 50 nm. The electron transport layer 160 may be formed of, for example, a compound represented by the following structural formula.

Further, the electron transport layer 160 may be formed of a known electron transport material. Examples of known electron transporting materials include tris (8-hydroxyquinolinato) aluminium (Alq3), compounds having a nitrogen-containing aromatic ring, and the like. Specific examples of the compound having a nitrogen-containing aromatic ring include oxadiazole derivatives such as 2- (4-tert-butylphenyl) -5- (4-biphenylyl) -1,3,4-oxadiazol. 1,3,5-tri [(3-pyridyl) -phen-3-yl] benzene-containing compound containing a pyridine (pyridine) ring, 2,4,6-tris (3'-(pyridin-3-yl] ) Biphenyl-3-yl) -1,3,5-triazine and other compounds containing a triazine ring, 2- (4- (N-phenylbenzoimimidazole-1-ylphenyl) -9,10-dimethylanthracene Examples thereof include compounds containing an imidazole ring.

An electron injection layer 170 is formed on the electron transport layer 160. The electron injection layer 170 is a layer having a function of facilitating the injection of electrons from the second electrode 180, and is formed with a thickness of about 0.3 nm to about 9 nm. As the electron injection layer 170, any material known as a material for forming the electron injection layer 170 can be used. For example, the electron injection layer 170 is composed of a Li complex such as lithium 8-quinolinate (Liq) and lithium fluoride (LiF), sodium chloride (NaCl), cesium fluoride (CsF), lithium oxide (Li ₂ O), or oxidation. It may be formed of barium (BaO) or the like.

A second electrode 180 is formed on the electron injection layer 170. The second electrode 180 is, for example, a cathode, and is formed as a reflective electrode by using a metal, an alloy, a conductive compound, or the like having a small work function. The second electrode 180 is, for example, a metal such as lithium (Li), magnesium (Mg), aluminum (Al), calcium (Ca), or aluminum-lithium (Al-Li), magnesium-indium (Mg-In), It may be formed of a mixture of metals such as magnesium-silver (Mg-Ag). Further, the second electrode 180 may be formed as a transmissive electrode by a thin film of the metal material having a diameter of 20 nm or less or a transparent conductive film such as indium tin oxide or zinc oxide.

Each of the above-mentioned layers can be formed by a known appropriate film forming method depending on the material, such as a vacuum vapor deposition method, a sputtering method, and various coating methods. Each organic layer arranged between the first electrode 120 and the second electrode 180 can be formed by, for example, various vapor deposition methods, various coating methods, and the like. Here, the Torquesen derivative represented by the general formula (1) can form an amorphous film and can form a smooth layer even in a coating method in which crystals are generally likely to be formed. Therefore, the layer containing the Torquesen derivative has particularly excellent smoothness and layer uniformity as compared with the case where the layer containing the Torquesen derivative is formed by the coating method using a conventional compound. Further, each metal layer such as the first electrode 120 and the second electrode 180 can be formed by, for example, a vacuum vapor deposition method, a sputtering method, or the like.

The example of the organic electroluminescent device 100 according to the present embodiment has been described above. Since the layer containing the Torquesen derivative according to the present embodiment in the organic electroluminescent device 100 has less surface irregularities, problems caused by the non-uniformity of each layer of the organic electroluminescent device 100, for example, the applied electric field. It is possible to prevent electric leakage and uneven light emission due to non-uniformity. Further, the organic electroluminescent device 100 according to the present embodiment contains the Torxen derivative represented by the general formula (1), so that the charge balance in the organic electroluminescent device 100 is suitably adjusted, and the luminous efficiency is improved. It will be excellent.

Next, the organic electroluminescent device according to another embodiment of the present invention will be described. FIG. 2 is a schematic view showing an example of an organic electroluminescent device according to another embodiment of the present invention. As shown in FIG. 2, the organic electroluminescent element 100A includes a substrate 110, a first electrode 120 arranged on the substrate 110, a hole injection layer 130 arranged on the first electrode 120, and a hole injection layer. It includes a light emitting layer 150A arranged on the light emitting layer 130, an electron injection layer 170 arranged on the light emitting layer 150A, and a second electrode 180 arranged on the electron injection layer 170.

Here, since the substrate 110, the first electrode 120, the hole injection layer 130, the electron injection layer 170, and the second electrode 180 have the same configuration as the corresponding members of the organic electroluminescent element 100, the description thereof will be omitted. ..

The light emitting layer 150A is a layer that emits light by fluorescence, phosphorescence, or the like, and is formed, for example, with a thickness of about 10 nm to about 200 nm, preferably 1 to 100 nm. Here, the light emitting layer 150A contains the above-mentioned Torquesen derivative. The light emitting layer 150A may be formed as, for example, a mixed layer of a dopant material and a host material. Specifically, the light emitting layer 150 may be formed as a mixed layer in which the dopant material is doped with 0.1 to 50% by mass, preferably 0.1 to 20% by mass, based on the total mass of the host material. In this case, for example, a Torquesen derivative can be used as a host material.

The host material may contain other compounds in addition to the Torquesen derivative described above. The light emitting layer 150A may further contain, for example, a compound having an electron transporting ability as a host material. As a result, the charge balance of the organic electroluminescent element 100 is further adjusted, and the luminous efficiency is improved. The compound having such an electron transporting ability can be the same as that described in the light emitting layer 150, and the ratio of the above-mentioned Torquesen derivative to the compound in the host material can also be the same.

An example of the organic electroluminescent device 100A according to the present embodiment has been described above. Since the organic electroluminescent device 100A according to the present embodiment has less unevenness on the surface of the light emitting layer 150A, a problem caused by the non-uniformity of the light emitting layer 150A of the organic electroluminescent device 100A, for example, the applied electric field is Leakage and uneven light emission due to non-uniformity are prevented. Further, the organic electroluminescent device 100A according to the present embodiment contains the Torquesen derivative represented by the general formula (1), so that the charge balance in the organic electroluminescent device 100A is suitably adjusted, and the luminous efficiency is increased. Will be excellent.

The laminated structure of the organic electroluminescent devices 100 and 100A according to the present embodiment is not limited to the above embodiment. The organic electroluminescent devices 100 and 100A according to the present embodiment may be formed by other known laminated structures. For example, the organic electroluminescent device 100 does not have to include one or more of the hole injection layer 130, the hole transport layer 140, the electron transport layer 160, and the electron injection layer 170, and also includes other layers. You may. Further, each layer of the organic electroluminescent devices 100 and 100A may be formed of a single layer or a plurality of layers.

Further, the organic electroluminescent device 100 includes a hole blocking layer between the hole transporting layer 140 and the light emitting layer 150 in order to prevent triplet excitons or holes from diffusing into the electron transporting layer 160. May be. The hole blocking layer can be formed by, for example, an oxadiazole derivative, a triazole derivative, a phenanthroline derivative, or the like.

Hereinafter, the Torquesen derivative according to the present embodiment and the organic electroluminescent device containing the Torquesen derivative will be specifically described with reference to Examples and Comparative Examples. The examples shown below are merely examples, and the Torquesen derivative and the organic electroluminescent device according to the present embodiment are not limited to the following examples.

[Synthesis of Torquesen derivatives]
First, a Torxen derivative was synthesized according to the method described below.

(A) Raw materials The starting materials and reagents and solvents used in the synthesis were all commercially available reagent grades without purification. As the dehydrated tetrahydrofuran (dehydrated THF), a commercially available product was purchased and used as it was. Further, as a filler used for column chromatography, spherical silica gel (neutral) manufactured by Kanto Chemical Co., Inc. was used.

In addition, 3,8,13-tribromo10,15-dihydro-5H-diindeno [1,2-a: 1', 2'-c] fluorene is described in B.I. Gomez-Lor, et al. , Eu. J. Org. Chem. It was synthesized with reference to the method described in 2001, 2107-2114.

(B) Identification method Each synthesized compound was identified by proton nuclear magnetic resonance ( ¹ H NMR) spectroscopy and mass spectrometry (mass (MS) spectrum). ^A Jeol JNM-ECX400 spectrophotometer (400 MHz) or a Jeol JNM-ECS400 spectrophotometer (400 MHz) was used for the measurement of the 1H NMR spectrum. For the measurement of the MS spectrum, the sample is ionized by the matrix-assisted laser desorption / ionization method (MALDI method) using α-cyano-4-hydroxysilicic acid (CHCA) as a matrix, and a time-of-flight (TOF) mass spectrometer is used. The MS spectrum was measured (MALDI-TOF-MS spectrum). The MALDI-TOF-MS measurement was performed using a Shimadzu-Kratos AXIMA-CFR PLUS TOF Mass spectrometer.

(C) Synthesis (Synthesis Example 1) Synthesis of Ph3-Tr (Comparative Example)
A compound (Ph3-Tr) represented by the following chemical formula was synthesized according to the procedure described below.

(I) Synthesis of Br3-Tr First, prior to the synthesis of Ph3-Tr, Br3-Tr, which is an intermediate in the synthesis of Ph3-Tr, was synthesized according to the following scheme.

A 50 mL two-necked flask is dried up and 3,8,13-tribromo 10,15-dihydro-5H-diindeno [1,2-a: 1', 2'-c] fluorene (also known as 3,) under a nitrogen atmosphere. A mixed solution containing 8,13-torksen) (116 mg, 0.200 mmol) and dehydrated THF (5.0 mL) was stirred in an ice bath. Then t-butoxypotassium (180 mg, 1.60 mmol) was added to the mixture. At this time, the mixed solution changed from pale yellow to deep red. After stirring for 1 hour, iodomethane (283 mg, 2.00 mmol) was slowly added, and the mixture was further stirred for 2 hours. Next, t-butoxypotassium (180 mg, 1.60 mmol) and iodomethane (283 mg, 2.00 mmol) were added in the same procedure as above, the ice bath was removed, and the mixture was stirred at room temperature for 12 hours. After completion of the reaction, the solvent was removed from the reaction mixture by an evaporator, chloroform was added to the reaction mixture, and the insoluble matter was removed by filtration. The filtrate is concentrated again on an evaporator, purified by silica gel column chromatography (developing solvent; chloroform / hexane = 1/2, volume ratio), and Br3-Tr (75.0 mg, 0.113 mmol, as an ivory-colored powder). 57%) was obtained.

^{1 1} H NMR (400 MHz, CDCl ₃ ) δ8.36 (d, J = 1.8 Hz, 3H), 7.51 (dd, J = 7.9 and 1.8 Hz, 3H), 7.40 ( d, J = 7.9 Hz, 3H), 1.83 (s, 18H); ¹³ C NMR (100 MHz, CDCl ₃ ) δ156.13, 149.34, 138.53, 134.89, 129.98 , 128.58, 124.09, 120.28, 46.84, 23.92; MALDI-TOF MS (m / z): [M + 2] ⁺ calcd for C ₃₃ H ₂₇ Br ₃ , 661.96; found, 661.96.

(Ii) Synthesis of Ph3-Tr Next, Ph3-Tr was synthesized according to the following scheme.

Br3-Tr (332 mg, 0.501 mmol), phenylboronic acid (305 mg, 2.50 mmol), tetrakis (triphenylphosphine) palladium (0) (57.8 mg, 0.0500 mmol) in toluene (17.5 mL) and ethanol. In addition to the mixed solvent of (4.0 mL), the inside of the reaction vessel was made into a nitrogen atmosphere. Potassium carbonate (691 mg, 5.00 mol) dissolved in water (4.0 mL) was added thereto, and then the obtained mixture was heated and stirred at 80 ° C. for 15 hours. The reaction mixture was allowed to cool to room temperature and then concentrated by removing the solvent under reduced pressure. The residue after concentration was extracted with chloroform-water using a separating funnel, and the obtained organic layer was dried over magnesium sulfate, and then the solvent was distilled off with an evaporator. After purification by silica gel column chromatography (developing solvent; chloroform / hexane = 1/2, volume ratio), recrystallization was performed from a mixed solvent of hexane-ethyl acetate to obtain Ph3-Tr as a white solid (88.0 mg, 0). .134 mmol, 27%).

^{1 1} H NMR (400 MHz, CDCl ₃ ) δ8.56 (s, 3H), 7.74 (dd, J = 7.9 and 1.4 Hz, 6H), 7.64 (dd, J = 7.3) and 1.4 Hz, 3H), 7.62 (d, J = 7.3 Hz, 3H), 7.54 (t, J = 7.3 Hz, 3H), 7.42 (t, J = 7) .3 Hz, 3H), 2.00 (s, 18H); ¹³ C NMR (100 MHz, CDCl ₃ ) δ156.66, 148.83, 142.07, 139.61, 137.34, 135.68, 128.96, 127.32, 127.13, 126.15, 124.67, 122.70, 46.75, 24.28; MALDI-TOF MS (m / z): M ⁺ calcd for C ₅₁ H ₄₂ , 654.33; found, 654.09.

(Synthesis Example 2) Synthesis of Compound 1 (Example)
The above-mentioned compound 1 was synthesized according to the following scheme.

Br3-Tr (133 mg, 0.201 mmol), dibenzo [b, d] thiophene-4-ylboronic acid (205 mg, 0.899 mmol), tetrakis (triphenylphosphine) palladium (0) (23.4 mg, 0.0202 mmol) Was added to a mixed solvent of toluene (7.1 mL) and ethanol (1.6 mL) to create a nitrogen atmosphere in the reaction vessel. Potassium carbonate (276 mg, 2.00 mol) dissolved in water (1.6 mL) was added thereto, and then the obtained mixture was heated and stirred at 80 ° C. for 20 hours. The reaction mixture was allowed to cool to room temperature and then concentrated by removing the solvent under reduced pressure. The residue after concentration was extracted with chloroform-water using a separating funnel, and the obtained organic layer was dried over magnesium sulfate, and then the solvent was distilled off with an evaporator. After purification by silica gel column chromatography (developing solvent; chloroform / hexane = 2/3, volume ratio), recrystallization was performed from a mixed solvent of ethyl acetate-ethanol to obtain Compound 1 as a white solid (142 mg, 0.146 mmol, 73%).

^{1 1} H NMR (400 MHz, CDCl ₃ ) δ8.66 (d, J = 1.4 Hz, 3H), 8.26-8.22 (m, 6H), 7,88 (dd, J = 7.3) and 1.4 Hz, 3H), 7.74 (dd, J = 7.7 and 1.4 Hz, 3H), 7.67-7.61 (m, 9H), 7.53-7.47 ( m, 6H), 2,000 (s, 18H); ¹³ C NMR (100 MHz, CDCl ₃ ) δ157.51, 149.32, 139.81, 138.96, 138.86, 137.97, 137. 43, 136.37, 136.01, 135.69, 127.33, 127.30, 126.90, 125.60, 125.36, 124.53, 122.91, 122.82, 121.89, 120.44, 47.02, 24.43; MALDI-TOF MS (m / z): M ⁺ calcd for C ₆₉ H ₄₈ S ₃ , 972.29; found, 972.29.

(Synthesis Example 3) Synthesis of Compound 18 (Example)
The above-mentioned compound 18 was synthesized according to the following scheme.

Br3-Tr (265 mg, 0.400 mmol), 2- (dibenzo [b, d] thiophen-2-yl) -4,4,5,5-tetramethyl-1,3,2-dioxaborolane (496 mg, 1. 60 mmol) and tetrakis (triphenylphosphine) palladium (0) (46.2 mg, 0.0400 mmol) were added to a mixed solvent of benzene (14 mL) and ethanol (3.2 mL) to create a nitrogen atmosphere in the reaction vessel. Potassium carbonate (544 mg, 4.00 mol) dissolved in water (3.2 mL) was added thereto, and then the obtained mixture was heated and stirred at 80 ° C. for 14 hours. The reaction mixture was allowed to cool to room temperature and then concentrated by removing the solvent under reduced pressure. The residue after concentration was extracted with chloroform-water using a separating funnel, the organic layer was dried over magnesium sulfate, and then the solvent was distilled off with an evaporator. After purification by silica gel column chromatography (developing solvent; chloroform / hexane = 1/2, volume ratio), compound 18 was obtained as a white solid by recrystallization from ethyl acetate (219 mg, 0.225 mmol, 56%). ..

^{1 1} H NMR (400 MHz, CDCl ₃ ) δ8.68 (s, 3H), 8.50 (d, J = 1.4 Hz, 3H), 8.29-8.27 (m, 3H), 8. 02 (d, J = 8.2 Hz, 3H), 7.93-7.89 (m, 3H), 7.85 (dd, J = 8.7 and 1.8 Hz, 3H), 7.76 (Dd, J = 7.8 and 1.4 Hz, 3H), 7.69 (d, J = 7.8 Hz, 3H), 7.56-7.49 (m, 6H), 2.07 (d, J = 7.8 Hz, 3H) s, 18H); ¹³ C NMR (100 MHz, CDCl ₃ ) δ156.77, 149.02, 140.14, 139.77, 138.86, 138.50, 137.57, 136.36, 135.82 , 135.69, 127.05, 126.51, 126.46, 125.08, 124.63, 123.34, 123.12, 122.97, 121.70, 120.30, 46.94, 24 .42; MALDI-TOF MS (m / z): M ⁺ calcd for C ₆₉ H ₄₈ S ₃ , 972.29; found, 972.60.

(Synthesis Example 4) Synthesis of Compound 22 (Example)
The above-mentioned compound 22 was synthesized according to the following scheme.

Br3-Tr (133 mg, 0.201 mmol), 9-Phenyl-3- (4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) -9H-carbazole (295 mg, 0. 80 mmol) and tetrakistriphenylphosphine palladium (0) (23.3 mg, 0.0202 mmol) were added to a mixed solvent of toluene (7.1 mL) and ethanol (1.6 mL) to create a nitrogen atmosphere in the reaction vessel. Potassium carbonate (276 mg, 4.00 mol) dissolved in water (1.6 mL) was added thereto, and then the obtained mixture was heated and stirred at 80 ° C. for 18 hours. The reaction mixture was allowed to cool to room temperature and then concentrated by removing the solvent under reduced pressure. The residue after concentration was extracted with chloroform-water using a separating funnel, and the obtained organic layer was dried over magnesium sulfate, and then the solvent was distilled off with an evaporator. After purification by silica gel column chromatography (chloroform: hexane = 1: 2), the obtained solid dispersed in an appropriate amount of methanol was suction-filtered to obtain Compound 22 as a white solid (88.0 mg, 0. 0765 mmol, 38%).

^{1 1} H NMR (400 MHz, CDCl ₃ ) δ8.70 (s, 3H), 8.49 (d, J = 1.4 Hz, 3H), 8.26 (d, J = 7.7 Hz, 3H) , 7.81 (dd, J = 8.7 and 1.8 Hz, 3H), 7.77 (dd, J = 7.7 and 1.3 Hz, 3H), 7.68-7.62 (m) , 15H), 7.58 (d, J = 8.6 Hz, 3H), 7.54-7.43 (m, 9H), 7.37-7.33 (m, 3H), 2.07 ( s, 18H); ¹³ C NMR (100 MHz, CDCl ₃ ) δ156.13, 148.94, 141.50, 140.50, 140.43, 137.82, 137.54, 135.92, 134.50 , 130.04, 127.63, 127.21, 126.39, 126.29, 125.79, 125.07, 124.10, 123.63, 122.77, 120.46, 120.18, 119. .00, 110.33, 110.07, 46.88, 24.48; MALDI-TOF MS (m / z): M ⁺ calcd for C ₈₇ H ₆₃ N ₃ , 1149.50; found, 1149.20.

(Synthesis Example 5) Synthesis of Compound 24 (Example)
The above-mentioned compound 24 was synthesized according to the following scheme.

Br3-Tr (133 mg, 0.201 mmol), dibenzo [b, d] furan-4-ylboronic acid (191 mg, 0.901 mmol), tetrakis (triphenylphosphine) palladium (0) (23.3 mg, 0.0202 mmol) Was added to a mixed solvent of toluene (7.1 mL) and ethanol (1.6 mL) to create a nitrogen atmosphere in the reaction vessel. Potassium carbonate (276 mg, 2.00 mol) dissolved in water (1.6 mL) was added thereto, and then the obtained mixture was heated and stirred at 85 ° C. for 14 hours. The reaction mixture was allowed to cool to room temperature and then concentrated by removing the solvent under reduced pressure. The residue after concentration was extracted with chloroform-water using a separating funnel, and the obtained organic layer was dried over magnesium sulfate, and then the solvent was distilled off with an evaporator. After purification by silica gel column chromatography (developing solvent; chloroform / hexane = 1/2, volume ratio), recrystallization was performed from a mixed solvent of ethyl acetate-ethanol to obtain Compound 24 as a white solid (111 mg, 0.120 mmol, 60%).

¹ H NMR (400 MHz, CDCl ₃ ) δ9.09 (s, 3H), 8.07 (d, J = 7.7 Hz, 3H), 8.02 (dd, J = 7.7 and 0.9) Hz, 3H), 7.87 (dd, J = 7.3 and 0.9 Hz, 3H), 7.78 (d, J = 7.2 Hz, 3H), 7.70 (d, J = 8) .2 Hz, 3H), 7.63 (d, J = 8.2 Hz, 3H), 7.55-7.51 (m, 6H), 7.42 (t, J = 7.7 Hz, 3H) ), 2.10 (s, 18H); ¹³ C NMR (100 MHz, CDCl ₃ ) δ157.35, 156.39, 153.60, 149.08, 137.36, 135.90, 134.45, 127 .46, 127.31, 126.97, 126.61, 126.56, 125.14, 124.52, 123.56, 122.98, 122.90, 120.95, 119.64, 111.87 , 47.17, 24.31; MALDI-TOF MS (m / z): M ⁺ calcd for C ₆₉ H ₄₈ O ₃ , 924.36; found, 924.28.

[Manufacturing of organic electroluminescent device]
Subsequently, using the coating method, an organic electroluminescent device containing the Torquesen derivative according to the present embodiment was produced by the following procedure.

(Example 1)
First, after patterning in advance, the washed ITO-glass substrate was surface-treated with ultraviolet rays / ozone (O ₃ ). The film thickness of the ITO film (first electrode) on the ITO-glass substrate was 150 nm.

Next, a mixed solution of water and isopropyl alcohol (1: 1, v / v) was added to 1.0 ml of a stock solution of PEDOT: PSS (Heraeus Co., Ltd., Clevios ™ PVP CH8000) to form a hole injection layer. Got Using this solution for forming a hole injection layer, spin coating was applied to an ITO-glass substrate under the conditions of 2000 rpm, 2 seconds, then 4000 rpm, and 60 seconds. Then, the ITO-glass substrate coated with the solution was dried at 105 ° C. for 60 minutes to form a hole injection layer (thickness: 40 nm) composed of PEDOT: PSS.

Next, compound 1: 5 mg as a Torxene derivative, Tris [2- (para-tolyl) pyridine] iridium (Tris [2- (p-tolyl) pyridine] iridium (III), Ir (mppy) ₃ ): 0. 50 mg, 2- (4-tert-butylphenyl) -5- (4-biphenylyl) -1,3,4-oxadiazole (PBD): 1.0 mg was dissolved in chloroform: 0.35 ml, and a light emitting layer was used. A solution for formation was obtained. Using this solution for forming a light emitting layer, spin coating was applied onto the hole injection layer of the ITO-glass substrate under the conditions of 2000 rpm, 10 seconds, then 3000 rpm, and 20 seconds. Then, the ITO-glass substrate coated with the solution was dried at 80 ° C. for 30 minutes to form a light emitting layer (thickness: 68 nm).

Subsequently, the substrate was transferred to the metal film forming deposition machine at 3.0 ^-4 Pa~3.6 ^-4 Pa degree of vacuum, an electron injection layer, and depositing a second electrode, the organic electroluminescent device Was produced. The electron injection layer was formed using CsF at a film forming rate of 0.1 Å / s at a film thickness of 1 nm, and the second electrode was formed using aluminum (Al) at a film thickness of 250 nm. The film forming conditions for the vapor deposition of aluminum were a film forming rate of 5.0 Å / s and a thickness of 50 nm, and then a film forming rate of 11.0 Å / s and a thickness of 200 nm.

(Example 2)
An organic electroluminescent device was produced in the same manner as in Example 1 except that compound 24 was used instead of compound 1 as the Torquesen derivative.

[Evaluation of coating film and film formation]
(Examples 3 and 4 and Comparative Examples 1 and 2)
Compounds 1, 22, 10,15-dihydro-5H-diindeno [1,2-a: 1', 2'-c] Fluorene (10,15-Dihydro-5H-diindeno [1,2-a: 1', 2'-c] fluorene, Torquesen) and Ph3-Tr were evaluated for film-forming properties. Specifically, first, in the same manner as in Example 1, patterning and cleaning of the ITO-glass substrate and formation of a hole injection layer (PEDOT: layer made of PSS) were performed. Next, 5 mg of Compounds 1 and 22, Torquesen or Ph3-Tr was dissolved in 0.3 ml of chloroform to prepare a Torquesen derivative solution. Using this Torquesen derivative solution, spin coating was applied onto the hole injection layer of the ITO-glass substrate under the conditions of 2000 rpm, 10 seconds, then 3000 rpm, and 20 seconds. Then, the ITO-glass substrate coated with the solution was dried at 80 ° C. for 30 minutes to form a Torxen derivative layer.

The surface roughness and film thickness of the formed Torxen derivative layer were measured. In the measurement of surface roughness, the surface of each Torxen derivative layer was measured over a range of 200 μm × 200 μm using a nanoscale hybrid microscope VN-8010 (manufactured by KEYENCE CORPORATION) equipped with a standard cantilever OP-75041. The arithmetic mean roughness Ra according to JIS B 0601-1994 was calculated. In the measurement of the film thickness, a cut was formed from the Torxen derivative layer using a cutter, and the height difference between the cut portion and the other portion was measured and calculated at a plurality of points. The average value of the height difference was regarded as the thickness of the hole injection layer and the Torxen derivative layer, and the value obtained by subtracting the hole injection layer thickness (40 nm) from the average value of the height difference was calculated as the thickness of the Torxen derivative layer. .. The results are shown in Table 1.

With reference to the results in Table 1, the Torquesen derivatives of Compounds 1 and 22 used in Examples 3 and 4 have extremely small surface roughness as compared with the Torquesen and Ph3-Tr used in Comparative Examples 1 and 2. It can be seen that the Torquesen derivative layer can be formed and the film forming property is good. Therefore, the light emitting layers formed in Examples 3 and 4 have a more uniform film thickness as compared with those of Comparative Examples 1 and 2, and problems caused by the non-uniformity of each layer of the light emitting element, for example, It is presumed that leakage and uneven light emission due to the non-uniformity of the applied electric field are more reliably prevented.

[Evaluation of element characteristics]
The evaluation results of the produced organic electroluminescent devices according to Examples 1 and 2 are shown in Table 2 below. A C9920-11 luminance orientation characteristic measuring device manufactured by Hamamatsu Photonics was used to evaluate the emission characteristics of the produced organic electroluminescent device.

With reference to the results in Table 2, the Torquesen derivative according to this embodiment showed a good external quantum yield.

As can be seen from the above results, the Torquesen derivative according to the present embodiment has a structure represented by the above-mentioned general formula (1), and thus has excellent film forming property when forming a layer. Further, it is possible to prevent problems caused by the non-uniformity of each layer of the organic electroluminescent device containing the Torquesen derivative according to the present embodiment, for example, electric leakage and uneven light emission due to non-uniformity of the applied electric field.

Although the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited to such examples. It is clear that a person having ordinary knowledge in the field of technology to which the present invention belongs can come up with various modifications or modifications within the scope of the technical ideas described in the claims. , These are also naturally understood to belong to the technical scope of the present invention.

100, 100A Organic electroluminescent device 110 Substrate 120 First electrode 130 Hole injection layer 140 Hole transport layer 150, 150A Light emitting layer 160 Electron transport layer 170 Electron injection layer 180 Second electrode

Claims (8)

Torquesen derivative represented by the following general formula (1).

In the above general formula (1)
R _{1 to} R ₆ are independent of each other, hydrogen atoms, linear, branched or cyclic alkyl groups having 1 to 16 substituted or unsubstituted carbon atoms, and substituted or unsubstituted carbon atoms 1 to 16. A linear or branched alkoxy group, an aryl group having a substituted or unsubstituted ring-forming carbon number of 6 to 36, or a heterocyclyl group having a substituted or unsubstituted ring-forming carbon number of 3 to 32.
X ₁ is a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothienyl group, or a substituted or unsubstituted carbazole-3-yl group,
X ₂ and X _3, independently of one another, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothienyl group, or a substituted or unsubstituted carbazole-3-yl group,
When X ₁ , X ₂ and X ₃ are substituted or unsubstituted carbazole-3-yl groups, X ₁ , X ₂ and X ₃ are all the same group.
X ₁ , X ₂ and X ₃ are not hexamethyltorxen groups. The Torxen derivative according to claim ₁ , wherein X ₁ , X ₂ and X ₃ are the same group. X _1, X ₂ and X _3, independently of one another, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothienyl group, or a substituted or unsubstituted carbazole-3-yl group, and The Torxen derivative according to claim 1 or 2, wherein X ₁ , X ₂ and X ₃ are respectively bonded to the Torxen skeleton at the benzene ring site thereof. R _{1 to} R ₆ are independent of each other, hydrogen atoms, linear, branched or cyclic alkyl groups having 1 to 7 substituted or unsubstituted carbon atoms, and substituted or unsubstituted carbon atoms 1 to 7. The Torquesen derivative according to any one of claims 1 to 3, which is a linear or branched alkoxy group of the above, or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms. The Torxene derivative according to any one of claims 1 to 4, wherein R _{1 to} R ₆ are linear alkyl groups, phenyl groups or alkylphenyl groups having 1 to 7 carbon atoms independently of each other. .. An organic electroluminescent device comprising the Torquesen derivative according to any one of claims 1 to 5. It has a light emitting layer, a hole transport layer and / or a hole injection layer,
The organic electroluminescent device according to claim 6, wherein the light emitting layer, the hole transporting layer and / or the hole injection layer contains the Torquesen derivative. A Torquesen derivative represented by any one of the following compounds 1 to 25 .