Aromatic compounds, organic electroluminescent devices, compositions, and methods for manufacturing organic electroluminescent devices.

Abstract

The present invention addresses the problem of providing an aromatic compound which has excellent heat resistance, excellent solubility, and excellent electron-transporting properties and which gives thin films having excellent resistance to alcohol solvents. The present invention relates to: an aromatic compound represented by formula (1); an organic electroluminescent element including an organic layer which comprises the aromatic compound as a material for organic electroluminescent elements; a composition for organic electroluminescent elements which comprises the aromatic compound and a solvent; and a method for producing the organic electroluminescent element. (In formula (1), G1, G2, and G3 respectively have the same meanings as defined in the specification.)

Description

[Technical Field]

[0001] The present invention relates to an aromatic compound that can be used in an organic electroluminescent device (hereinafter sometimes referred to as "OLED" or "device"), an organic electroluminescent device having the compound, a display device and a lighting device having the organic electroluminescent device, a composition containing the compound and a solvent, a thin film formation method, and a method for manufacturing an organic electroluminescent device. [Background technology]

[0002] In recent years, the development of organic electroluminescent devices (OLEDs) using organic thin films has shifted from those using inorganic materials to organic electroluminescent devices. Organic electroluminescent devices (OLEDs) typically have a hole injection layer, a hole transport layer, an organic light-emitting layer, and an electron transport layer between the anode and cathode. Suitable materials for each of these layers are being developed, and development is progressing on light-emitting colors such as red, green, and blue. In addition, research is underway on coating-type OLEDs, which have higher material utilization efficiency and lower manufacturing costs compared to conventional deposition-type OLEDs.

[0003] In solution-processed OLEDs, there is a demand for longer lifespan and lower power consumption for the organic electroluminescent element. While various factors can affect the lifespan and power consumption of organic electroluminescent elements, the thermal durability and crystallinity of the materials constituting the organic electroluminescent element are considered to have a significant impact on lifespan.

[0004] Furthermore, in order to manufacture organic electroluminescent devices using the wet deposition method, all materials used must be soluble in organic solvents and usable as inks. If the materials have poor solubility, operations such as prolonged heating will be required, which may cause the materials to deteriorate before use. In addition, if a uniform state cannot be maintained in the solution state for a long period of time, precipitation of the material will occur from the solution, making film formation by inkjet devices or other means impossible. Materials used in the wet deposition method require solubility in two senses: rapid dissolution in organic solvents and the ability to maintain a uniform state without precipitation after dissolution.

[0005] Patent Document 1 reports on OLED materials using aromatic compounds containing a triazine structure, such as the following compound (C-1), as charge transport materials for phosphorescent compounds.

[0006] [ka]

[0007] Patent Document 2 reports an OLED material using triazine and aromatic compounds containing a spirobifluorene structure, such as the following compounds (C-2) to (C-4), as a material for improving the lifespan of the layer.

[0008] [ka] [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] International Publication No. 2012 / 137958 [Patent Document 2] U.S. Patent No. 9960363 [Overview of the project] [Problems that the invention aims to solve]

[0010] However, compound (C-1) has a low glass transition temperature of 93°C, resulting in insufficient heat resistance. Compounds (C-2) to (C-4) are not suitable for use as charge transport materials in an emissive layer because their electron mobility is insufficient, leading to low device efficiency and device lifetime. Furthermore, they lack sufficient resistance to alcohol solvents for laminating thin films deposited from compounds (C-1) to (C-4) using a wet deposition method with alcohol solvents.

[0011] This invention has been made in view of the above-mentioned conventional circumstances, and aims to provide an aromatic compound having excellent heat resistance, excellent solubility, excellent electron transport properties, and excellent durability of thin films to alcohol solvents.

[0012] Furthermore, the present invention aims to provide an organic electroluminescent element having the compound, a display device and a lighting device having the organic electroluminescent element, a composition containing the compound and a solvent, a thin film formation method, and a method for manufacturing an organic electroluminescent element.

[0013] In this specification, "alcohol solvent" may be referred to as "alcohol-based solvent" or "alcohol-based solvent." [Means for solving the problem]

[0014] As a result of diligent research by the present inventors, we discovered that the above problems can be solved by using triazine and aromatic compounds with a spirobifluorene structure, and thus arrived at the present invention.

[0015] In other words, the gist of this invention is as follows: <1> ~ <21> That is correct. <1> An aromatic compound represented by the following formula (1).

[0016] [ka]

[0017] (In formula (1), G 1 and G 2 Each independently represents the following equation (3), G 3 This represents equation (4) below.

[0018] [ka]

[0019] (In equation (3), the asterisk (*) indicates a combination with equation (1), L 2is a group formed by linking a plurality of groups selected from a divalent aromatic hydrocarbon group having 60 or less carbon atoms which may have a substituent, a divalent heteroaromatic group having 60 or less carbon atoms which may have a substituent, or a divalent aromatic hydrocarbon group having 60 or less carbon atoms which may have a substituent and a divalent heteroaromatic group having 60 or less carbon atoms which may have a substituent, Ar 2 is a group formed by linking a plurality of groups selected from a monovalent aromatic hydrocarbon group having 60 or less carbon atoms which may have a substituent, a monovalent heteroaromatic group having 60 or less carbon atoms which may have a substituent, or a monovalent aromatic hydrocarbon group having 60 or less carbon atoms which may have a substituent and a monovalent heteroaromatic group having 60 or less carbon atoms which may have a substituent, a 2 represents an integer of 1 to 5.)

[0020]

Chemical formula

[0021]

Chemical formula

[0022] (In formula (2), the asterisk (*) represents the bond with formula (1), L 1This is a group formed by linking multiple groups selected from a divalent aromatic hydrocarbon group having 60 or fewer carbon atoms which may have substituents, a divalent heteroaromatic group having 60 or fewer carbon atoms which may have substituents, or a divalent aromatic hydrocarbon group having 60 or fewer carbon atoms which may have substituents and a divalent heteroaromatic group having 60 or fewer carbon atoms which may have substituents. Ar 1 This is a group formed by linking multiple groups selected from a monovalent aromatic hydrocarbon group having 60 or fewer carbon atoms which may have substituents, a monovalent heteroaromatic group having 60 or fewer carbon atoms which may have substituents, and a monovalent aromatic hydrocarbon group having 60 or fewer carbon atoms which may have substituents. a 1 (This represents an integer between 0 and 5.) <3> L 1 ~L 3 However, each is independently a phenyl group or a group consisting of multiple linked phenyl groups. <2> Aromatic compounds as described above. <4> L 1 ~L 3 However, each is independently a 1,3-phenylene group or a 1,4-phenylene group. <2> or <3> Aromatic compounds as described above. <5> The molecular weight is 1200 or more. <1> ~ <4> An aromatic compound listed in any one of the following. <6> An organic electroluminescent element having an anode and a cathode on a substrate, with an organic layer between the anode and the cathode, The aforementioned organic layer has a layer containing a material for an organic electroluminescent device. The aforementioned organic electroluminescent material <1> ~ <5> An organic electroluminescent element that is an aromatic compound listed in any one of the following. <7> The layer containing the aforementioned organic electroluminescent material is a light-emitting layer. <6> Organic electroluminescent device as described above. <8> <6> or <7> A display device having the organic electroluminescent element described above. <9> <6> or <7> A lighting device having the organic electroluminescent element described above.

[0023] <10> <1> ~ <5> A composition for an organic electroluminescent element, comprising an aromatic compound and a solvent as described in any one of the following. <11> Furthermore, it contains phosphorescent material and charge transport material, <10> The organic electroluminescent light-emitting composition described above. <12> The charge transport material is a compound represented by the following formula (240), or a compound represented by the following formula (260). <11> The organic electroluminescent light-emitting composition described above.

[0024] [ka]

[0025] (In formula (240), Ar 611 Ar 612 Each of these independently represents a monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms, which may have substituents. R 611 , R 612 Each is independently a deuterium atom, a halogen atom, or a monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have substituents. G represents a single bond or a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms, which may have substituents. n 611 , n 612 Each of these is an independent integer between 0 and 4.

[0026] [ka]

[0027] (In formula (260), Ar 21 ~Ar 35 Each of these independently represents a hydrogen atom, an optionally substituted phenyl group, or a monovalent group consisting of 2 to 10 optionally substituted phenyl groups, either unbranched or branched and linked together. <13> Ar in equation (240) 611 and Ar 612 Each of these is independently a monovalent group in which multiple benzene rings, which may have substituents, are linked in a chain or branched manner. <12> The organic electroluminescent light-emitting composition described above. <14> R in equation (240) 611 and R 612 Each of these is a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms, which may each have substituents independently. <12> or <13> The organic electroluminescent light-emitting composition described above. <15> n in equation (240) 611 and n 612 Each of them is independently either 0 or 1. <12> ~ <14> A composition for an organic electroluminescent element as described in any one of the following. <16> In the above equation (260), Ar 21 Ar 25 Ar 26 Ar 30 Ar 31 and Ar 35 It is a hydrogen atom, Ar 22 ~Ar 24 Ar 27 ~Ar 29 , and Ar 32 ~Ar 34 is a hydrogen atom, a phenyl group, and one of the structures selected from the following formulas (261-1) to (261-9), and these structures may have the substituents. <12> The organic electroluminescent light-emitting composition described above.

[0028] [ka]

[0029] <17> <10> ~ <16> A thin film formation method comprising the step of forming a film of an organic electroluminescent element composition described in any one of the above by a wet film formation method. <18> A method for manufacturing an organic electroluminescent element having an anode and a cathode on a substrate, with an organic layer between the anode and the cathode, The above-mentioned, <10> ~ <16> A method for manufacturing an organic electroluminescent element, comprising the step of forming it by a wet film deposition method using an organic electroluminescent element composition described in any one of the above. <19> The aforementioned organic layer is a light-emitting layer. <18> A method for manufacturing an organic electroluminescent element as described above. <20> A method for manufacturing an organic electroluminescent element having an anode and a cathode on a substrate, with an organic layer between the anode and the cathode, The organic layer includes a light-emitting layer and an electron transport layer. The aforementioned light-emitting layer, <10> ~ <16> A step of forming by a wet film deposition method using any one of the organic electroluminescent element compositions described in, A method for manufacturing an organic electroluminescent element, comprising the steps of: forming the electron transport layer by a wet film deposition method using an electron transport layer composition containing an electron transport material and a solvent, in this order. <21> The solvent contained in the electron transport layer composition is an alcohol-based solvent. <20> A method for manufacturing an organic electroluminescent element as described above. [Effects of the Invention]

[0030] The present invention makes it possible to provide aromatic compounds that have excellent heat resistance, excellent solubility, excellent electron transport properties, and excellent durability of thin films in alcohol solvents.

[0031] Furthermore, the present invention can provide an organic electroluminescent element having the compound, a display device and a lighting device having the organic electroluminescent element, a composition containing the compound and a solvent, a thin film formation method, and a method for manufacturing an organic electroluminescent element. [Brief explanation of the drawing]

[0032] [Figure 1] Figure 1 is a schematic cross-sectional view showing an example of the structure of the organic electroluminescent element of the present invention. [Modes for carrying out the invention]

[0033] The embodiments of the present invention will be described in detail below, but the present invention is not limited to the embodiments described below and can be implemented in various ways within the scope of its gist.

[0034] In the present invention, "may have substituents" means that it may have one or more substituents.

[0035] <Aromatic compound of the present invention> The aromatic compound of the present invention is represented by the following formula (1).

[0036] [ka]

[0037] (In formula (1), G 1 and G 2 Each independently represents the following equation (3), G 3 This represents equation (4) below.

[0038] [ka]

[0039] (In equation (3), the asterisk (*) indicates a combination with equation (1), L 2 This is a group formed by linking multiple groups selected from a divalent aromatic hydrocarbon group having 60 or fewer carbon atoms which may have substituents, a divalent heteroaromatic group having 60 or fewer carbon atoms which may have substituents, or a divalent aromatic hydrocarbon group having 60 or fewer carbon atoms which may have substituents and a divalent heteroaromatic group having 60 or fewer carbon atoms which may have substituents. Ar 2This is a group formed by linking multiple groups selected from a monovalent aromatic hydrocarbon group having 60 or fewer carbon atoms which may have substituents, a monovalent heteroaromatic group having 60 or fewer carbon atoms which may have substituents, and a monovalent aromatic hydrocarbon group having 60 or fewer carbon atoms which may have substituents. a 2 (This represents an integer between 1 and 5.)

[0040] [ka]

[0041] (In equation (4), the asterisk (*) indicates a combination with equation (1), L 3 This is a group formed by linking multiple groups selected from a divalent aromatic hydrocarbon group having 60 or fewer carbon atoms which may have substituents, a divalent heteroaromatic group having 60 or fewer carbon atoms which may have substituents, or a divalent aromatic hydrocarbon group having 60 or fewer carbon atoms which may have substituents and a divalent heteroaromatic group having 60 or fewer carbon atoms which may have substituents. a 3 (This represents an integer between 1 and 5.)

[0042] From the perspective of electron transport, G 1 It is preferable that it is represented by the following formula (2).

[0043] [ka]

[0044] (In equation (2), the asterisk (*) indicates a combination with equation (1), L 1 This is a group formed by linking multiple groups selected from a divalent aromatic hydrocarbon group having 60 or fewer carbon atoms which may have substituents, a divalent heteroaromatic group having 60 or fewer carbon atoms which may have substituents, or a divalent aromatic hydrocarbon group having 60 or fewer carbon atoms which may have substituents and a divalent heteroaromatic group having 60 or fewer carbon atoms which may have substituents. Ar 1 This is a group formed by linking multiple groups selected from a monovalent aromatic hydrocarbon group having 60 or fewer carbon atoms which may have substituents, a monovalent heteroaromatic group having 60 or fewer carbon atoms which may have substituents, and a monovalent aromatic hydrocarbon group having 60 or fewer carbon atoms which may have substituents. a 1 (This represents an integer between 0 and 5.)

[0045] In the present invention, the mechanism by which the effective effect is obtained is presumed to be as follows.

[0046] The aromatic compounds of the present invention have a spirobifluorene structure represented by formula (4), and therefore have a high glass transition temperature. Because the triazine skeleton and the spirobifluorene structure are bonded via a larger structure than biphenyl, the steric hindrance caused by the spirobifluorene structure is suppressed, resulting in high electron transport properties. Furthermore, because the aromatic compounds of the present invention have a biphenyl group bonded at the meta position to the spirobifluorene structure represented by formula (4), they have high solubility. The compounds of the present invention have a large molecular weight and possess at least one spirobifluorene structure, resulting in excellent resistance to alcohol solvents after film formation.

[0047] Furthermore, in the frontier molecular orbitals of the aromatic compound of the present invention, the LUMO orbital is easily localized to the triazine structure represented by formula (1), and the HOMO orbital is easily localized to the spirobifluorene structure represented by formula (3), thereby improving durability.

[0048] Using the aromatic compound of the present invention, it is possible to easily provide an organic electroluminescent element that exhibits excellent driving stability and can be driven with low driving voltage and high efficiency.

[0049] The organic electroluminescent element of the present invention, which contains the aromatic compound of the present invention, exhibits excellent electrochemical stability, low driving voltage, and high efficiency. Therefore, the organic electroluminescent element of the present invention has potential applications in flat panel displays (e.g., displays for office automation computers and wall-mounted televisions), in-vehicle display elements, mobile phone displays, and light sources that take advantage of their surface-emitting properties (e.g., light sources for photocopiers, liquid crystal displays and instrument backlights), display boards, and indicator lights, and thus has great technical value.

[0050] <Ar 1 Ar 2 > Ar 1 Ar 2 Each of these independently represents a monovalent aromatic hydrocarbon group having 60 or fewer carbon atoms that may have substituents, a monovalent heteroaromatic group having 60 or fewer carbon atoms that may have substituents, or a group formed by linking multiple groups selected from a monovalent aromatic hydrocarbon group having 60 or fewer carbon atoms that may have substituents and a monovalent heteroaromatic group having 60 or fewer carbon atoms that may have substituents.

[0051] Examples of monovalent aromatic hydrocarbon groups with 60 or fewer carbon atoms include monovalent groups of benzene rings, naphthalene rings, anthracene rings, phenanthrene rings, tetraphenylene rings, chrysene rings, pyrene rings, benzoanthracene rings, perylene rings, biphenyl rings, or terphenyl rings.

[0052] Examples of monovalent heteroaromatic groups with 60 or fewer carbon atoms include monovalent groups of furan rings, benzofuran rings, dibenzofuran rings, thiophene rings, benzothiophene rings, dibenzothiophene rings, pyrrole rings, pyrazole rings, imidazole rings, oxadiazole rings, indole rings, carbazole rings, pyrroloimidazole rings, pyrrolopyrrole rings, pyrrolopyrrole rings, thienopyrrole rings, thienopyrrole rings, phlopyrrole rings, phlofuran rings, thienofuran rings, benzoisoxazole rings, benzoisothiazole rings, benzimidazole rings, pyridine rings, pyrazine rings, pyridazine rings, pyrimidine rings, triazine rings, quinoline rings, isoquinoline rings, sinnoline rings, quinoxaline rings, perimidine rings, quinazoline rings, quinazolinone rings, or azulene rings.

[0053] From the viewpoint of the solubility and durability of the compound, it is preferable that the compound be a phenyl group, a group consisting of multiple linked phenyl groups, or a naphthyl group, and more preferably a phenyl group or a group consisting of multiple linked phenyl groups.

[0054] <L 1 , L 2 , L 3 > L 1 , L 2 , L 3 Each of these independently represents a divalent aromatic hydrocarbon group having 60 or fewer carbon atoms that may have substituents, a divalent heteroaromatic group having 60 or fewer carbon atoms that may have substituents, or a group formed by linking multiple groups selected from a divalent aromatic hydrocarbon group having 60 or fewer carbon atoms that may have substituents and a divalent heteroaromatic group having 60 or fewer carbon atoms that may have substituents.

[0055] Examples of divalent aromatic hydrocarbon groups with 60 or fewer carbon atoms include the divalent groups of benzene, naphthalene, anthracene, tetraphenylene, phenanthrene, chrysene, pyrene, benzoanthracene, or perylene rings.

[0056] Examples of divalent heteroaromatic groups with 60 or fewer carbon atoms include the divalent groups of furan rings, benzofuran rings, dibenzofuran rings, thiophene rings, benzothiophene rings, dibenzothiophene rings, pyrrole rings, pyrazole rings, imidazole rings, oxadiazole rings, indole rings, carbazole rings, pyrroloimidazole rings, pyrrolopyrrole rings, pyrrolopyrrole rings, thienopyrrole rings, thienopyrrole rings, phlopyrrole rings, phlofuran rings, thienofuran rings, benzoisoxazole rings, benzoisothiazole rings, benzimidazole rings, pyridine rings, pyrazine rings, pyridazine rings, pyrimidine rings, triazine rings, quinoline rings, isoquinoline rings, sinnoline rings, quinoxaline rings, perimidine rings, quinazoline rings, quinazolinone rings, or azulene rings.

[0057] From the viewpoint of the solubility and durability of the compound, it is preferable that the compound be a phenyl group, a group consisting of multiple linked phenyl groups, or a naphthyl group, and more preferably a phenyl group or a group consisting of multiple linked phenyl groups. Of these, a 1,3-phenylene group or a 1,4-phenylene group is even more preferable.

[0058] 1 ~a 3 > a 1 represents an integer from 0 to 5, and a 2 and a 3 Each of these independently represents an integer from 1 to 5. From the viewpoint of the solubility and durability of the compound, a 1 and a 3 is preferably 3 or less, more preferably 2 or less, and particularly preferably 1, a 2 It is preferable that the value is 4 or less, and even more preferable that it is 3 or less.

[0059] a 1 ~a 3 If there are 2 or more, multiple L 1 ~L 3 They may be the same or different.

[0060] <(L 1 ) a1 , (L 2 ) a2 , (L 3 ​) a3 > (L 1 ) a1 、(L 2 ) a2 、(L 3 ) a3 At least one of (L 1 ), (L 2 ), and (L 3 ) preferably has at least one partial structure selected from the partial structure represented by the following formula (11), the partial structure represented by the following formula (12), and the partial structure represented by the following formula (13) from the viewpoints of the solubility and durability of the compound.

[0061]

Chemical formula

[0062] In each of the above formulas (11) to (13), * represents a bond with an adjacent structure or a hydrogen atom, and at least one of the two * represents the bonding position with an adjacent structure. In the following descriptions, unless otherwise specified, the definition of * is the same.

[0063] More preferably, at least one of (L 1 ), (L 2 ), and (L 3 ) has at least the partial structure represented by formula (11) or the partial structure represented by formula (12). 1 ) a1 、(L 2 / / 原文重复,翻译时保留 [[ID=X37]] 2 ) a2 、(L 3 / / 原文重复,翻译时保留 [[ID=X41]] 3 ) a3 の少なくとも一つは、少なくとも式(11)で表される部分構造又は式(12)で表される部分構造を有する。 さらに好ましくは、(L 1 [[ID=X47]] 1 ) a1 、(L 2 [[ID=X51]] 2 ) a2 、(L 3 [[ID=X55]] 3 ) [[ID=X56]] a3 a3 がそれぞれ、少なくとも式(11)で表される部分構造又は式(12)で表される部分構造を有する。 特に好ましくは、(L 2 [[ID=X61]] 2 ) a2 が、式(11)で表される部分構造及び式(12)で表される部分構造を有する。

[0064] 式(12)として好ましくは、下記式(12-2)である。

[0065] 注:原文中存在一些重复的行号,翻译时保留了原文格式。若原文格式有误,可能会影响翻译的准确性,请根据实际情况进行调整。 [ka]

[0066] More preferably than formula (12), the following formula (12-3) is used.

[0067] [ka]

[0068] Furthermore, in the case of having a substructure represented by formula (11) and a substructure represented by formula (12), it is even more preferable to have at least one substructure selected from the following formulas (14) to (18), which is a structure that includes multiple structures selected from the substructure represented by formula (11) and the substructure represented by formula (12).

[0069] [ka]

[0070] A structure that includes multiple structures selected from the substructures represented by equation (11) and the substructures represented by equation (12) is, for example, equation (14), which is a substructure having one substructure represented by equation (11) and two substructures represented by equation (12), as shown in equation (14a) below.

[0071] [ka]

[0072] Furthermore, more preferably, (L 1 ) a1 , (L 2 ) a2 , (L 3 ) a3 At least one of them has at least one substructure represented by formula (14) or formula (15).

[0073] Formula (14) is preferably the following formula (14-2).

[0074] [ka]

[0075] More preferably, formula (14) is formula (14-3) below.

[0076] [ka]

[0077] Formula (15) is preferably the following formula (15-2).

[0078] [ka]

[0079] More preferably, formula (15) is formula (15-3) below.

[0080] [ka]

[0081] Formula (17) is preferably the following formula (17-2).

[0082] [ka]

[0083] Formula (18) is preferably the following formula (18-2).

[0084] [ka]

[0085] Furthermore, it is more preferable that the structure including the substructure represented by formula (13) has a substructure represented by the following formula (19) or a substructure represented by the following formula (20).

[0086] [ka]

[0087] In equations (14) to (20) above, * represents a bond with an adjacent structure or a hydrogen atom, and at least one of the two *s represents a bond position with an adjacent structure.

[0088] Among formulas (14) to (20), formulas (14-3) and (15-3) are preferred, and formula (14-3) is even more preferred.

[0089] <Substituent> Ar 1 ~Ar 2 , L 1 ~L 3 The substituents that may be present can be selected from the substituent group Z.

[0090] [Substituent group Z] Examples of substituent group Z include alkyl groups, alkenyl groups, alkynyl groups, alkoxy groups, aryloxy groups, alkoxycarbonyl groups, acyl groups, halogen atoms, haloalkyl groups, alkylthio groups, arylthio groups, silyl groups, siloxy groups, cyano groups, aralkyl groups, aromatic hydrocarbon groups, or heteroaromatic groups.

[0091] Examples of alkyl groups include linear, branched, or cyclic alkyl groups having typically 1 or more carbon atoms, preferably 4 or more, and typically 24 or less, preferably 10 or less, such as methyl, ethyl, branched, linear, or cyclic propyl, branched, linear, or cyclic butyl, branched, linear, or cyclic pentyl, branched, linear, or cyclic hexyl, branched, linear, or cyclic octyl, branched, linear, or cyclic nonyl, and branched, linear, or cyclic dodecyl groups. From the viewpoint of compound stability, methyl, ethyl, branched, linear, or cyclic propyl, and branched, linear, or cyclic butyl groups are preferred, and branched propyl groups are particularly preferred.

[0092] Examples of alkenyl groups include vinyl groups and other alkenyl groups that typically have 2 or more carbon atoms, usually 24 or fewer, and preferably 12 or fewer.

[0093] Examples of alkynyl groups include ethynyl groups and other alkynyl groups that typically have 2 or more carbon atoms, usually 24 or fewer, and preferably 12 or fewer.

[0094] Examples of alkoxy groups include methoxy groups, ethoxy groups, and other alkoxy groups that typically have one or more carbon atoms, and usually 24 or fewer, preferably 12 or fewer.

[0095] Examples of aryloxy groups include phenoxy groups, naphthoxy groups, pyridyloxy groups, etc., which typically have 4 or more carbon atoms, preferably 5 or more, and typically 36 or fewer carbon atoms, preferably 24 or fewer carbon atoms, as well as aryloxy or heteroaryloxy groups.

[0096] Examples of alkoxycarbonyl groups include methoxycarbonyl groups and ethoxycarbonyl groups, which typically have 2 or more carbon atoms, usually 24 or fewer, and preferably 12 or fewer.

[0097] Examples of acyl groups include acetyl groups, benzoyl groups, and other acyl groups that typically have 2 or more carbon atoms, usually 24 or fewer, and preferably 12 or fewer.

[0098] Examples of halogen atoms include fluorine atoms and chlorine atoms.

[0099] Examples of haloalkyl groups include a trifluoromethyl group and other haloalkyl groups that typically have one or more carbon atoms, usually 12 or fewer, and preferably 6 or fewer.

[0100] Examples of alkylthio groups include methylthio groups, ethylthio groups, and other alkylthio groups that typically have one or more carbon atoms, usually 24 or fewer, and preferably 12 or fewer.

[0101] Examples of arylthio groups include phenylthio groups, naphthylthio groups, and pyridylthio groups, which typically have 4 or more carbon atoms, preferably 5 or more, and typically 36 or fewer carbon atoms, preferably 24 or fewer.

[0102] Examples of silyl groups include trimethylsilyl groups and triphenylsilyl groups, which typically have 2 or more carbon atoms, preferably 3 or more, and typically 36 or fewer carbon atoms, preferably 24 or fewer.

[0103] Examples of siloxy groups include trimethylsiloxy groups and triphenylsiloxy groups, which typically have 2 or more carbon atoms, preferably 3 or more, and typically 36 or fewer carbon atoms, preferably 24 or fewer.

[0104] Examples of aralkyl groups include benzyl group, 2-phenylethyl group, 2-phenylpropyl-2-yl group, 2-phenylbutyl-2-yl group, 3-phenylpentyl-3-yl group, 3-phenyl-1-propyl group, 4-phenyl-1-butyl group, 5-phenyl-1-pentyl group, 6-phenyl-1-hexyl group, 7-phenyl-1-heptyl group, and 8-phenyl-1-octyl group, which typically have 7 or more carbon atoms, preferably 9 or more, typically 30 or less, preferably 18 or less, and more preferably 10 or less.

[0105] Examples of aromatic hydrocarbon groups include benzene rings, naphthalene rings, anthracene rings, tetraphenylene rings, phenanthrene rings, chrysene rings, pyrene rings, benzoanthracene rings, or perylene rings, which typically have 6 or more carbon atoms, typically 30 or fewer, preferably 18 or fewer, and more preferably 10 or fewer.

[0106] Examples of heteroaromatic groups include heteroaromatic groups having typically 4 or more carbon atoms, typically 30 or less, preferably 18 or less, and more preferably 12 or less carbon atoms, such as furan rings, benzofuran rings, dibenzofuran rings, thiophene rings, benzothiophene rings, dibenzothiophene rings, pyrrole rings, pyrazole rings, imidazole rings, oxadiazole rings, indole rings, carbazole rings, pyrroloimidazole rings, pyrrolopyrazole rings, pyrrolopyrrole rings, thienopyrrole rings, thienopyrrole rings, phlopyrrole rings, phlofuran rings, thienofuran rings, benzoisoxazole rings, benzoisothiazole rings, benzimidazole rings, pyridine rings, pyrazine rings, pyridazine rings, pyrimidine rings, triazine rings, quinoline rings, isoquinoline rings, sinnoline rings, quinoxaline rings, perimidine rings, quinazoline rings, quinazolinone rings, or azulene rings.

[0107] Among the substituent group Z described above, preferably are alkyl groups, alkoxy groups, aralkyl groups, and aromatic hydrocarbon groups; more preferably are alkyl groups having 10 or fewer carbon atoms, aralkyl groups having 30 or fewer carbon atoms, and aromatic hydrocarbon groups having 30 or fewer carbon atoms; even more preferably are aromatic hydrocarbon groups having 30 or fewer carbon atoms; and particularly preferably have no substituents.

[0108] Furthermore, each substituent in the substituent group Z may have further substituents. The same substituents as those in the substituent group Z can be used as these further substituents. From the viewpoint of charge transport, it is preferable that the substituents in the substituent group Z do not have further substituents.

[0109] <Molecular weight> The molecular weight of the aromatic compound of the present invention is preferably 1000 or more, more preferably 1100 or more, most preferably 1200 or more, preferably 5000 or less, more preferably 4000 or less, particularly preferably 3000 or less, and most preferably 2000 or less.

[0110] <Specific example> Specific examples of aromatic compounds of the present invention are shown below, but the present invention is not limited to these.

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[0135] <Method for Producing Aromatic Compound> The aromatic compound of the present invention can be produced, for example, according to the method described in the examples.

[0136] [Use of Aromatic Compound] The aromatic compound of the present invention is preferably used as a material for an organic electroluminescent device in the organic layer of the organic electroluminescent device, and the organic layer is preferably a light-emitting layer. The organic electroluminescent device can have, for example, an anode and a cathode on a substrate and an organic layer between the anode and the cathode. When the aromatic compound of the present invention is used in the light-emitting layer, it is preferably used as a host material of the light-emitting layer.

[0137] The organic layer containing the aromatic compound of the present invention may be formed by a vapor deposition method or a wet film-forming method.

[0138] In this specification, when the aromatic compound of the present invention is used in the organic layer of an organic electroluminescent device, the aromatic compound of the present invention is also referred to as a material for organic electroluminescent devices.

[0139] [Composition] When an organic layer containing the aromatic compound of the present invention is formed by a wet film deposition method, a composition containing at least the aromatic compound represented by formula (1) and a solvent (hereinafter sometimes referred to as "organic solvent") is wet-deposited. That is, the composition of the present invention contains at least the aromatic compound represented by formula (1) and an organic solvent.

[0140] The composition of the present invention is suitably used as a composition for an organic electroluminescent element for forming an organic electroluminescent element.

[0141] The composition of the present invention preferably further contains a light-emitting material and is suitably used as a composition for forming the light-emitting layer of an organic electroluminescent device. A phosphorescent material is preferred as the light-emitting material.

[0142] The composition of the present invention preferably further comprises a light-emitting material and a charge transport material, and is suitably used as a composition for forming the light-emitting layer of an organic electroluminescent device. A phosphorescent material is preferred as the light-emitting material.

[0143] <Organic solvents> The organic solvent contained in the composition of the present invention is a volatile liquid component used to form a layer containing the aromatic compound of the present invention by wet film formation.

[0144] The organic solvent is not particularly limited as long as it is an organic solvent that readily dissolves the aromatic compound of the present invention, which is the solute, and the luminescent material described later.

[0145] Preferred organic solvents include, for example, alkanes such as n-decane, cyclohexane, ethylcyclohexane, decalin, and bicyclohexane; aromatic hydrocarbons such as toluene, xylene, mesitylene, phenylcyclohexane, tetralin, and methylnaphthalene; halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene, and trichlorobenzene; and aromatics such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenethole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole, and diphenyl ether. Alicyclic ethers; aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate; alicyclic ketones such as cyclohexanone, cyclooctanone, and fencone; alicyclic alcohols such as cyclohexanol and cyclooctanol; aliphatic ketones such as methyl ethyl ketone and dibutyl ketone; aliphatic alcohols such as butanol and hexanol; aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA); and so on.

[0146] Among these, alkanes, aromatic hydrocarbons, aromatic ethers, and aromatic esters are preferred from the viewpoint of viscosity and boiling point, aromatic hydrocarbons, aromatic ethers, and aromatic esters are more preferred, and aromatic hydrocarbons and aromatic esters are particularly preferred.

[0147] These organic solvents may be used individually, or two or more may be used in any combination and ratio.

[0148] The boiling point of the organic solvent used is usually 80°C or higher, preferably 100°C or higher, more preferably 120°C or higher, and usually 380°C or lower, preferably 350°C or lower, more preferably 330°C or lower. If the boiling point of the organic solvent falls below this range, the stability of the film formation may decrease during wet film formation due to solvent evaporation from the composition. If the boiling point of the organic solvent exceeds this range, the stability of the film formation may decrease during wet film formation due to solvent residue after film formation.

[0149] In particular, a uniform coating film can be produced by combining two or more organic solvents with a boiling point of 150°C or higher. If there is one or fewer organic solvents with a boiling point of 150°C or higher, a uniform film may not be formed during coating.

[0150] <Luminescent materials> The composition of the present invention is preferably a composition for forming an emissive layer, and in this case, it is preferable that it further contains an emissive material. The emissive material refers to the component that mainly emits light in the organic electroluminescent device composition of the present invention, and corresponds to the dopant component in an organic electroluminescent device.

[0151] As the light-emitting material, known materials can be used, and fluorescent light-emitting materials or phosphorescent light-emitting materials can be used individually or in combination. However, from the viewpoint of internal quantum efficiency, phosphorescent light-emitting materials are preferred.

[0152] (Phosphorescent material) Phosphorescent materials are materials that exhibit light emission from an excited triplet state. Typical examples include metal complex compounds containing Ir, Pt, Eu, etc., and materials with a metal complex structure are preferred.

[0153] Among metal complexes, examples of phosphorescent organometallic complexes that emit light via a triplet state include Werner-type complexes or organometallic complex compounds containing a metal selected from groups 7 to 11 of the long-period periodic table (hereinafter, unless otherwise specified, "periodic table" refers to the long-period periodic table) as the central metal. As such phosphorescent materials, compounds represented by the following formula (201) or compounds represented by the formula (205) described later are preferred, and compounds represented by the following formula (201) are more preferred.

[0154] [ka]

[0155] M is a metal selected from groups 7 through 11 of the periodic table, such as ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, gold, and europium.

[0156] Ring A1 represents an aromatic hydrocarbon ring structure or an aromatic heterocyclic structure that may have substituents.

[0157] Ring A2 represents an aromatic heterocyclic structure that may have substituents.

[0158] R 201 , R 202 Each of these is an independent structure represented by the above formula (202), and "*" indicates bonding with ring A1 or ring A2. 201 , R 202 R can be the same or different, 201 , R 202 If there are multiple instances of each, they may be the same or different.

[0159] Ar 201 Ar 203 Each of these independently represents an aromatic hydrocarbon ring structure that may have substituents, or an aromatic heterocyclic ring structure that may have substituents.

[0160] Ar202 This represents an optionally substituted aromatic hydrocarbon ring structure, an optionally substituted aromatic heterocyclic structure, or an optionally substituted aliphatic hydrocarbon structure.

[0161] Substituents bonded to ring A1 may bond to each other, substituents bonded to ring A2 may bond to each other, or substituents bonded to ring A1 and substituents bonded to ring A2 may bond to each other to form a ring.

[0162] B 201 -L 200 -B 202 This represents an anionic bidentate ligand. 201 and B 202 Each of these independently represents a carbon atom, an oxygen atom, or a nitrogen atom, and these atoms may be atoms that constitute a ring. 200 is a single bond, or B 201 and B 202 B represents the group of atoms that together constitute a bidentate ligand. 201 -L 200 -B 202 If multiple instances exist, they may be identical or different.

[0163] i1 and i2 each independently represent integers between 0 and 12 (inclusive). i3 is Ar 202 It is a non-negative integer, with the upper limit being the number of values ​​that can be substituted for it. j is Ar 201 It is a non-negative integer, with the upper limit being the number of values ​​that can be substituted for it. k1 and k2 are non-negative integers, each independently, with the upper limit being the number of permutations in ring A1 and ring A2, respectively. m is an integer between 1 and 3.

[0164] The aromatic hydrocarbon ring in ring A1 is preferably an aromatic hydrocarbon ring having 6 to 30 carbon atoms, and specifically, a benzene ring, naphthalene ring, anthracene ring, triphenylyl ring, acenaphthene ring, fluorantene ring, or fluorene ring is preferred.

[0165] The aromatic heterocycle in ring A1 is preferably an aromatic heterocycle having 3 to 30 carbon atoms and containing a nitrogen atom, an oxygen atom, or a sulfur atom as a heteroatom, and more preferably a furan ring, a benzofuran ring, a thiophene ring, or a benzothiophene ring.

[0166] More preferably, ring A1 is a benzene ring, a naphthalene ring, or a fluorene ring, particularly preferably a benzene ring or a fluorene ring, and most preferably a benzene ring.

[0167] The aromatic heterocycle in ring A2 is preferably an aromatic heterocycle having 3 to 30 carbon atoms, containing one of a nitrogen atom, an oxygen atom, or a sulfur atom as a heteroatom. Specifically, these include pyridine rings, pyrimidine rings, pyrazine rings, triazine rings, imidazole rings, oxazole rings, thiazole rings, benzothiazole rings, benzoxazole rings, benzimidazole rings, quinoline rings, isoquinoline rings, quinoxaline rings, quinazoline rings, naphthyridine rings, and phenanthidine rings. More preferably, the rings are pyridine rings, pyrazine rings, pyrimidine rings, imidazole rings, benzothiazole rings, benzoxazole rings, quinoline rings, isoquinoline rings, quinoxaline rings, and quinazoline rings. More preferably, a pyridine ring, an imidazole ring, a benzothiazole ring, a quinoline ring, an isoquinoline ring, a quinoxaline ring, or a quinazoline ring. Most preferably, the rings are pyridine rings, imidazole rings, benzothiazole rings, quinoline rings, quinoxaline rings, and quinazoline rings.

[0168] A preferred combination of ring A1 and ring A2 can be expressed as (ring A1 - ring A2), These are (benzene ring-pyridine ring), (benzene ring-quinoline ring), (benzene ring-quinoxaline ring), (benzene ring-quinazoline ring), (benzene ring-imidazole ring), and (benzene ring-benzothiazole ring).

[0169] The substituents that rings A1 and A2 may have can be arbitrarily selected, but preferably one or more substituents selected from the substituent group S described later.

[0170] Ar 201 Ar 202 Ar 203 If any of the aromatic hydrocarbon ring structures may have substituents, The aromatic hydrocarbon ring structure is preferably an aromatic hydrocarbon ring having 6 to 30 carbon atoms. Specifically, benzene rings, naphthalene rings, anthracene rings, triphenylyl rings, acenaphthene rings, fluorantene rings, and fluorene rings are preferred. More preferably, a benzene ring, a naphthalene ring, or a fluorene ring is preferred. Most preferably, it is a benzene ring.

[0171] Ar 201 Ar 202 Ar 203 If either of the elements is a fluorene ring which may have substituents, it is preferable that the 9th and 9' positions of the fluorene ring have substituents or are bonded to adjacent structures.

[0172] Ar 201 Ar 202 Ar 203 If any of the elements is a benzene ring which may have substituents, it is preferable that at least one benzene ring is bonded to an adjacent structure at the ortho or meta position, and more preferably that at least one benzene ring is bonded to an adjacent structure at the meta position.

[0173] Ar 201 Ar 202 Ar 203 If any of the elements is an aromatic heterocyclic structure which may have substituents, The aromatic heterocyclic structure is preferably an aromatic heterocyclic ring having 3 to 30 carbon atoms, containing one of a nitrogen atom, an oxygen atom, or a sulfur atom as a heteroatom. Specifically, these include pyridine rings, pyrimidine rings, pyrazine rings, triazine rings, imidazole rings, oxazole rings, thiazole rings, benzothiazole rings, benzoxazole rings, benzimidazole rings, quinoline rings, isoquinoline rings, quinoxaline rings, quinazoline rings, naphthyridine rings, phenanthidine rings, carbazole rings, dibenzofuran rings, and dibenzothiophene rings. More preferably, the rings are pyridine rings, pyrimidine rings, triazine rings, carbazole rings, dibenzofuran rings, and dibenzothiophene rings.

[0174] Ar 201 Ar 202 Ar 203 If either of the elements is a carbazole ring which may have substituents, it is preferable that the N-position of the carbazole ring has a substituent or is bonded to an adjacent structure.

[0175] Ar 202 If it is an aliphatic hydrocarbon structure which may have substituents, The aliphatic hydrocarbon structure is a linear, branched, or cyclic aliphatic hydrocarbon structure. Preferably, it is an aliphatic hydrocarbon having 1 to 24 carbon atoms. More preferably, it is an aliphatic hydrocarbon having 1 to 12 carbon atoms. More preferably, it is an aliphatic hydrocarbon having 1 to 8 carbon atoms.

[0176] i1 and i2 are each independently preferably integers from 1 to 12, more preferably integers from 1 to 8, and more preferably integers from 1 to 6. This range is expected to improve solubility and charge transport.

[0177] i3 preferably represents an integer between 0 and 5, more preferably an integer between 0 and 2, and more preferably 0 or 1.

[0178] j preferably represents an integer between 0 and 2, and more preferably 0 or 1.

[0179] k1 and k2 preferably represent integers between 0 and 3, more preferably between 1 and 3, more preferably 1 or 2, and particularly preferably 1.

[0180] Ar 201 Ar 202 Ar 203 The substituents that may be present can be arbitrarily selected, but preferably one or more substituents selected from the substituent group S described below, more preferably a hydrogen atom, an alkyl group, or an aryl group, particularly preferably a hydrogen atom, an alkyl group, and most preferably unsubstituted (hydrogen atom).

[0181] Unless otherwise specified, the substituent is preferably a group selected from the following substituent group S.

[0182] <Substituent group S> Alkyl alkyl groups, preferably C1 to C20 alkyl groups, more preferably C1 to C12 alkyl groups, even more preferably C1 to C8 alkyl groups, and particularly preferably C1 to C6 alkyl groups. • Alkoxy groups, preferably alkoxy groups having 1 to 20 carbon atoms, more preferably alkoxy groups having 1 to 12 carbon atoms, and even more preferably alkoxy groups having 1 to 6 carbon atoms. • An aryloxy group, preferably an aryloxy group having 6 to 20 carbon atoms, more preferably an aryloxy group having 6 to 14 carbon atoms, even more preferably an aryloxy group having 6 to 12 carbon atoms, and particularly preferably an aryloxy group having 6 carbon atoms. A heteroaryloxy group, preferably a heteroaryloxy group having 3 to 20 carbon atoms, more preferably a heteroaryloxy group having 3 to 12 carbon atoms. • Alkylamino group, preferably an alkylamino group having 1 to 20 carbon atoms, more preferably an alkylamino group having 1 to 12 carbon atoms. • An arylamino group, preferably an arylamino group having 6 to 36 carbon atoms, more preferably an arylamino group having 6 to 24 carbon atoms. Aralkyl groups, preferably aralkyl groups having 7 to 40 carbon atoms, more preferably aralkyl groups having 7 to 18 carbon atoms, and even more preferably aralkyl groups having 7 to 12 carbon atoms. • Heteroaralkyl groups, preferably heteroaralkyl groups having 7 to 40 carbon atoms, more preferably heteroaralkyl groups having 7 to 18 carbon atoms. Alkenyl groups, preferably alkenyl groups having 2 to 20 carbon atoms, more preferably alkenyl groups having 2 to 12 carbon atoms, even more preferably alkenyl groups having 2 to 8 carbon atoms, and particularly preferably alkenyl groups having 2 to 6 carbon atoms. • Alkynyl group, preferably an alkynyl group having 2 to 20 carbon atoms, more preferably an alkynyl group having 2 to 12 carbon atoms. • An aryl group, preferably an aryl group having 6 to 30 carbon atoms, more preferably an aryl group having 6 to 24 carbon atoms, even more preferably an aryl group having 6 to 18 carbon atoms, and particularly preferably an aryl group having 6 to 14 carbon atoms. Heteroaryl groups, preferably heteroaryl groups having 3 to 30 carbon atoms, more preferably heteroaryl groups having 3 to 24 carbon atoms, even more preferably heteroaryl groups having 3 to 18 carbon atoms, and particularly preferably heteroaryl groups having 3 to 14 carbon atoms. • Alkylsilyl group, preferably an alkylsilyl group having 1 to 20 carbon atoms in the alkyl group, more preferably an alkylsilyl group having 1 to 12 carbon atoms in the alkyl group. • An arylsilyl group, preferably an arylsilyl group having 6 to 20 carbon atoms in the aryl group, more preferably an arylsilyl group having 6 to 14 carbon atoms in the aryl group. • Alkylcarbonyl group, preferably an alkylcarbonyl group having 2 to 20 carbon atoms. • Arylcarbonyl group, preferably an arylcarbonyl group having 7 to 20 carbon atoms. Hydrogen atom, deuterium atom, fluorine atom, cyano group, or -SF5.

[0183] The above groups may have one or more hydrogen atoms replaced by fluorine atoms, or one or more hydrogen atoms replaced by deuterium atoms.

[0184] Unless otherwise specified, aryls are aromatic hydrocarbons, and heteroaryls are aromatic heterocycles.

[0185] (Preferred group among substituent group S) Of these substituent groups S, Preferably, alkyl groups, alkoxy groups, aryloxy groups, arylamino groups, aralkyl groups, alkenyl groups, aryl groups, heteroaryl groups, alkylsilyl groups, arylsilyl groups, groups in which one or more hydrogen atoms of these groups are replaced by fluorine atoms, fluorine atoms, cyano groups, or -SF5. More preferably alkyl groups, arylamino groups, aralkyl groups, alkenyl groups, aryl groups, heteroaryl groups, groups in which one or more hydrogen atoms of these groups are replaced by fluorine atoms, fluorine atoms, cyano groups, or -SF5. More preferably, alkyl groups, alkoxy groups, aryloxy groups, arylamino groups, aralkyl groups, alkenyl groups, aryl groups, heteroaryl groups, alkylsilyl groups, and arylsilyl groups. Particularly preferred are alkyl groups, arylamino groups, aralkyl groups, alkenyl groups, aryl groups, and heteroaryl groups. Most preferably, the group is an alkyl group, an arylamino group, an aralkyl group, an aryl group, or a heteroaryl group.

[0186] These substituent groups S may further have substituents selected from substituent group S. Preferred groups, more preferred groups, even more preferred groups, particularly preferred groups, and most preferred groups of the substituents that may be present are the same as preferred groups within substituent group S.

[0187] (Preferred structure of formula (201)) Among the structures represented by formula (202) in formula (201), structures having a group to which a benzene ring is linked, structures having an aromatic hydrocarbon group or an aromatic heterocyclic group to which an alkyl group or aralkyl group is bonded to ring A1 or ring A2, and structures to which a dendron is bonded to ring A1 or ring A2 are preferred.

[0188] In a structure having a group with linked benzene rings, Ar 201 The structure is a benzene ring, i1 is 1 to 6, and at least one of the benzene rings is bonded to an adjacent structure at the ortho or meta position. This structure is expected to improve both solubility and charge transport.

[0189] In a structure having an aromatic hydrocarbon group or an aromatic heterocyclic group to which an alkyl group or aralkyl group is bonded to ring A1 or ring A2, Ar 201 The structure is an aromatic hydrocarbon structure or an aromatic heterocyclic structure, and i1 is 1 to 6. Ar 202 The structure is an aliphatic hydrocarbon structure, and i2 is 1 to 12, preferably 3 to 8. Ar 203 It has a benzene ring structure, and i3 is either 0 or 1. In this structure, preferably, Ar 201 This is the aforementioned aromatic hydrocarbon structure, more preferably a structure in which 1 to 5 benzene rings are linked together, and more preferably a single benzene ring. This structure is expected to improve both solubility and charge transport.

[0190] In a structure in which a dendron is attached to ring A1 or ring A2, Ar 201 Ar 202 It has a benzene ring structure, Ar 203 It has a biphenyl or terphenyl structure, i1 and i2 are between 1 and 6, i3 is 2, and j is 2. This structure is expected to improve both solubility and charge transport.

[0191] B 201 -L 200 -B 202Among the structures represented by the formulas (203) or (204), the structure represented by the formula (203) or (204) below is preferred.

[0192] [ka]

[0193] R 211 , R 212 , R 213 represents a substituent. The substituent is not particularly limited, but is preferably a group selected from the substituent group S.

[0194] [ka]

[0195] Ring B3 represents an aromatic heterocyclic structure containing a nitrogen atom, which may have substituents. Ring B3 is preferably a pyridine ring. The substituents that ring B3 may have are not particularly limited, but are preferably groups selected from the substituent group S.

[0196] The phosphorescent material represented by equation (201) is not particularly limited, but the following structures are examples. Note that Me stands for methyl group and Ph stands for phenyl group.

[0197] [ka]

[0198] [ka]

[0199] [ka]

[0200] [ka]

[0201] [ka]

[0202] [ka]

[0203] Here, we will explain the compound represented by the following formula (205).

[0204] [ka]

[0205] In formula (205), M 2 R represents a metal, and T represents a carbon or nitrogen atom. 92 ~R 95 Each of these independently represents a substituent. However, if T is a nitrogen atom, then R 94 and R 95 It does not exist.

[0206] In formula (205), M 2 represents a metal. Specific examples include metals selected from groups 7 to 11 of the periodic table. Among these, ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, or gold are preferred, and divalent metals such as platinum and palladium are particularly preferred.

[0207] Also, in equation (205), R 92 and R 93 Each of these independently represents a hydrogen atom, a halogen atom, an alkyl group, an aralkyl group, an alkenyl group, a cyano group, an amino group, an acyl group, an alkoxycarbonyl group, a carboxyl group, an alkoxy group, an alkylamino group, an aralkylamino group, a haloalkyl group, a hydroxyl group, an aryloxy group, an aromatic hydrocarbon group, or an aromatic heterocyclic group.

[0208] Furthermore, if T is a carbon atom, R 94 and R 95 Each of them is independent of R 92 and R 93 This represents substituents represented by similar examples. Furthermore, if T is a nitrogen atom, R is directly bonded to T. 94 or R 95 It does not exist.

[0209] Also, R 92 ~R 95 It may further have substituents. Examples of substituents include R 92 and R 93 The substituents listed above can be used as follows. Furthermore, R 92 ~R 95 Any two or more of these groups may be linked together to form a ring.

[0210] (molecular weight) The molecular weight of the phosphorescent material is preferably 5000 or less, more preferably 4000 or less, and particularly preferably 3000 or less. Alternatively, the molecular weight of the phosphorescent material is usually 1000 or more, preferably 1100 or more, and more preferably 1200 or more. This molecular weight range allows the phosphorescent materials to mix uniformly with the compound and / or other charge transport material of the present invention without aggregation, resulting in a highly efficient luminescent layer.

[0211] A large molecular weight is preferable for phosphorescent materials because it results in high Tg, melting point, and decomposition temperature, providing excellent heat resistance for the phosphorescent material and the formed luminescent layer, and reducing the likelihood of deterioration of film quality due to gas generation, recrystallization, and molecular migration, as well as an increase in impurity concentration due to thermal decomposition of the material. On the other hand, a small molecular weight is preferable for phosphorescent materials because it facilitates the purification of organic compounds.

[0212] [Charge transport material] When the composition of the present invention is a composition for forming a light-emitting layer, it is preferable to include, in addition to the aromatic compound of the present invention, a charge transport material other than the aromatic compound of the present invention as a further host material.

[0213] The charge transport material used as the host material for the light-emitting layer is a material having a framework with excellent charge transport properties, and is preferably selected from electron transport materials, hole transport materials, and bipolar materials capable of transporting both electrons and holes. Furthermore, in this invention, the term "charge transport material" also includes materials that adjust charge transport properties.

[0214] Examples of skeletons with excellent charge transport properties include aromatic structures, aromatic amine structures, triarylamine structures, dibenzofuran structures, naphthalene structures, phenanthrene structures, phthalocyanine structures, porphyrin structures, thiophene structures, benzylphenyl structures, fluorene structures, quinacridone structures, triphenylene structures, carbazole structures, pyrene structures, anthracene structures, phenanthroline structures, quinoline structures, pyridine structures, pyrimidine structures, triazine structures, oxadiazole structures, or imidazole structures.

[0215] In the composition of the present invention, since the compound represented by formula (1) functions as an electron transport material, it is preferable to further include a hole transport material as a charge transport material. The hole transport material is a compound having a structure excellent in hole transport, and among the skeletons excellent in charge transport, a carbazole structure, a dibenzofuran structure, a triarylamine structure, a naphthalene structure, a phenanthrene structure, or a pyrene structure is preferred as a structure excellent in hole transport, and a carbazole structure, a dibenzofuran structure, or a triarylamine structure is even more preferred. Particularly preferred is a compound represented by formula (240), which will be described later.

[0216] The charge transport material used as the host material for the light-emitting layer is preferably a compound having a fused ring structure of three or more rings, and more preferably a compound having two or more fused ring structures of three or more rings, or a compound having at least one fused ring of five or more rings. These compounds increase the rigidity of the molecules, making it easier to suppress the degree of molecular motion that responds to heat. Furthermore, the fused rings of three or more rings and the fused rings of five or more rings preferably have aromatic hydrocarbon rings or aromatic heterocycles, in terms of charge transport properties and material durability.

[0217] Examples of fused ring structures with three or more rings include anthracene structures, phenanthrene structures, pyrene structures, chrysene structures, naphthacene structures, triphenylene structures, fluorene structures, benzofluorene structures, indenofluorene structures, indolofluorene structures, carbazole structures, indenocarbazole structures, indolocarbazole structures, dibenzofuran structures, and dibenzothiophene structures.

[0218] From the viewpoint of charge transport and solubility, at least one selected from the group consisting of phenanthrene structure, fluorene structure, indenofluorene structure, carbazole structure, indenocarbazole structure, indolocarbazole structure, dibenzofuran structure, and dibenzothiophene structure is preferred, and from the viewpoint of resistance to electric charge, the carbazole structure or indolocarbazole structure is more preferred.

[0219] Among the charge transport materials used as host materials for the light-emitting layer, a compound represented by formula (260), described later, which has a structure in which many benzene rings are linked together, is preferred as a material for adjusting the charge transport properties. It is thought that by including this compound as a host material, the excitons generated in the light-emitting layer are efficiently recombined, thereby increasing the luminescence efficiency, and that the charge transport properties in the light-emitting layer are appropriately adjusted, suppressing the degradation of the light-emitting material and extending the operating life.

[0220] When the composition of the present invention is a composition for forming an emissive layer, it is preferable to include, in addition to the compound of the present invention which has excellent electron transport properties, a compound represented by formula (240) and / or a compound represented by formula (260) described later as charge transport materials. Including such compounds as further host materials is preferable from the viewpoint of adjusting the charge balance in the emissive layer and from the viewpoint of luminescence efficiency.

[0221] The charge transport material used as the host material for the light-emitting layer is preferably a polymer material from the viewpoint of excellent flexibility. A light-emitting layer formed using a material with excellent flexibility is preferred as the light-emitting layer of an organic electroluminescent device formed on a flexible substrate. When the charge transport material used as the host material included in the light-emitting layer is a polymer material, the molecular weight is preferably 5,000 to 1,000,000, more preferably 10,000 to 500,000, and more preferably 10,000 to 100,000.

[0222] Furthermore, the charge transport material used as the host material for the light-emitting layer is preferably a low molecular weight material from the viewpoint of ease of synthesis and purification, ease of designing electron transport performance and hole transport performance, and ease of viscosity adjustment when dissolved in a solvent. When the charge transport material used as the host material contained in the light-emitting layer is a low molecular weight material, the molecular weight is preferably 5,000 or less, more preferably 4,000 or less, particularly preferably 3,000 or less, most preferably 2,000 or less, usually 600 or more, preferably 800 or more, more preferably 1,100 or more, and when the layer formed in contact with the light-emitting layer is formed by a wet film deposition method, it is preferably 1,000 or more, more preferably 1,100 or more, and particularly preferably 1,200 or more.

[0223] <Compound represented by formula (240)> [ka]

[0224] (In formula (240), Ar611 Ar 612 Each of these independently represents a monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms, which may have substituents. R 611 , R 612 Each is independently a deuterium atom, a halogen atom, or a monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have substituents. G represents a single bond or a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms, which may have substituents. n 611 , n 612 Each of these is an independent integer between 0 and 4.

[0225] <Ar 611 Ar 612 > Ar 611 Ar 612 Each of these independently represents a monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms, which may have substituents. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 50, more preferably 6 to 30, and even more preferably 6 to 18. Specifically, examples of aromatic hydrocarbon groups include monovalent groups of aromatic hydrocarbon structures having typically 6 or more carbon atoms, typically 30 or less, preferably 18 or less, and even more preferably 14 or less, such as benzene rings, naphthalene rings, anthracene rings, tetraphenylene rings, phenanthrene rings, chrysene rings, pyrene rings, benzoanthracene rings, or perylene rings, or monovalent groups of structures in which multiple structures selected from these structures are linked in a chain or branched manner. When multiple aromatic hydrocarbon rings are linked, typically 2 to 8 linked rings are used, and 2 to 5 linked rings are preferred. When multiple aromatic hydrocarbon rings are linked, the same structure may be linked, or different structures may be linked.

[0226] Ar 611 Ar 612 Preferably, each independently Phenyl group, A monovalent group in which multiple benzene rings are linked together in a chain or branched manner. A monovalent group in which one or more benzene rings and at least one naphthalene ring are linked in a chain or branched manner. A monovalent group in which one or more benzene rings and at least one phenanthrene ring are linked in a chain or branched manner, A monovalent group in which one or more benzene rings and at least one tetraphenylene ring are linked in a chain or branched manner, More preferably, it is a monovalent group in which multiple benzene rings are linked in a chain or branched manner, and in either case, the order of bonding does not matter. Ar 611 Ar 612 It is particularly preferable that each of these is a monovalent group in which a plurality of benzene rings, which may have substituents, are linked in a chain or branched manner, and most preferably that each of these is a monovalent group in which a plurality of benzene rings are linked in a chain or branched manner.

[0227] As mentioned above, the number of bonded benzene rings, naphthalene rings, phenanthrene rings, and tetraphenylene rings is usually 2 to 8, and preferably 2 to 5. Particularly preferred are monovalent structures with 1 to 4 linked benzene rings, monovalent structures with 1 to 4 linked benzene rings and a naphthalene ring, monovalent structures with 1 to 4 linked benzene rings and a phenanthrene ring, or monovalent structures with 1 to 4 linked benzene rings and a tetraphenylene ring.

[0228] These aromatic hydrocarbon groups may have substituents. The substituents that the aromatic hydrocarbon groups may have are as described above, and specifically can be selected from substituent group Z2. Preferred substituents are preferred substituents from substituent group Z2.

[0229] Ar 611 Ar 612 From the viewpoint of compound solubility and durability, it is preferable that at least one of the components has at least one substructure selected from the following formulas (72-1) to (72-7).

[0230] [ka]

[0231] In equations (72-1) to (72-7) above, * represents a bond with an adjacent structure or a hydrogen atom, and at least one of the two *s represents a bond position with an adjacent structure. The definition of * is the same in the following descriptions unless otherwise specified.

[0232] more preferably, Ar 611 Ar 612 At least one of them has at least one substructure selected from formulas (72-1) to (72-4) and formula (72-7). More preferably, Ar 611 Ar 612 Each of these has at least one substructure selected from equations (72-1) to (72-3) and equation (72-7). Particularly preferred, Ar 611 Ar 612 Each of these has at least one substructure selected from formulas (72-1), (72-2), and (72-7).

[0233] Formula (72-2) is preferably the following formula (72-2-2).

[0234] [ka]

[0235] More preferably than formula (72-2), the formula is (72-2-3) shown below.

[0236] [ka]

[0237] Furthermore, Ar 611 Ar 612 Examples of substructures that are preferable to have at least one of include a substructure represented by formula (72-1) and a substructure having a substructure represented by formula (72-2).

[0238] <R 611 , R 612 > R 611 , R 612 Each of these is independently a monovalent aromatic hydrocarbon having 6 to 50 carbon atoms, which may have a deuterium atom, a halogen atom such as a fluorine atom, or substituents. Preferably, it is a monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms, which may have substituents. Examples of aromatic hydrocarbon groups include monovalent groups of aromatic hydrocarbon structures having 6 to 30 carbon atoms, more preferably 6 to 18 carbon atoms, and particularly preferably 6 to 10 carbon atoms. Specifically, the monovalent aromatic hydrocarbon group is the aforementioned Ar 611 The same applies to the preferred aromatic hydrocarbon group, and the preferred group is a phenyl group. These aromatic hydrocarbon groups may have substituents. The substituents that the aromatic hydrocarbon groups may have are as described above, and specifically can be selected from the substituent group Z2 described later. Preferred substituents are the preferred substituents of substituent group Z2 described later.

[0239] <n 611 , n 612 > n 611 , n 612 Each of these is an integer between 0 and 4, preferably between 0 and 2, and more preferably 0 or 1.

[0240] <Substituent> Ar 611 Ar 612 , R 611 , R 612 When is a monovalent aromatic hydrocarbon group, the substituents that may be present are preferably those selected from the substituent group Z2 below.

[0241] <Substituent group Z2> The substituent group Z2 consists of alkyl groups, alkoxy groups, aryloxy groups, heteroaryloxy groups, alkoxycarbonyl groups, dialkylamino groups, diarylamino groups, arylalkylamino groups, acyl groups, halogen atoms, haloalkyl groups, alkylthio groups, arylthio groups, silyl groups, siloxy groups, cyano groups, aromatic hydrocarbon groups, and aromatic heterocyclic groups. These substituents may include linear, branched, or cyclic structures.

[0242] More specifically, the substituent group Z2 can be represented by the following structures. For example, linear, branched, or cyclic alkyl groups having typically 1 or more carbon atoms, preferably 4 or more, typically 24 or less, preferably 12 or less, more preferably 8 or less, and even more preferably 6 or less; such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, tert-butyl, n-hexyl, cyclohexyl, and dodecyl groups; For example, alkoxy groups such as methoxy groups and ethoxy groups, which typically have 1 or more carbon atoms, typically 24 or fewer, and preferably 12 or fewer; For example, aryloxy groups or heteroaryloxy groups such as phenoxy groups, naphthoxy groups, and pyridyloxy groups, which typically have 4 or more carbon atoms, preferably 5 or more, typically 36 or fewer, and preferably 24 or fewer; For example, alkoxycarbonyl groups such as methoxycarbonyl groups and ethoxycarbonyl groups, which typically have 2 or more carbon atoms, typically 24 or fewer, and preferably 12 or fewer; For example, dialkylamino groups such as dimethylamino groups and diethylamino groups, which typically have 2 or more carbon atoms, typically 24 or fewer, and preferably 12 or fewer; For example, diarylamino groups such as diphenylamino groups and ditlylamino groups, which typically have 10 or more carbon atoms, preferably 12 or more, typically 36 or less, and preferably 24 or less carbon atoms; For example, an arylalkylamino group such as a phenylmethylamino group, which typically has 7 or more carbon atoms, typically 36 or fewer, and preferably 24 or fewer carbon atoms; For example, acyl groups such as acetyl groups and benzoyl groups, which typically have 2 or more carbon atoms, typically 24 or fewer, and preferably 12 or fewer; For example, halogen atoms such as fluorine atoms and chlorine atoms; For example, a haloalkyl group such as a trifluoromethyl group, which usually has 1 or more carbon atoms, usually 12 or fewer, and preferably 6 or fewer carbon atoms; For example, alkylthio groups such as methylthio groups and ethylthio groups, which typically have 1 or more carbon atoms, typically 24 or fewer, and preferably 12 or fewer carbon atoms; For example, arylthio groups such as phenylthio groups, naphthylthio groups, and pyridylthio groups, which typically have 4 or more carbon atoms, preferably 5 or more, typically 36 or fewer, and preferably 24 or fewer; For example, silyl groups such as trimethylsilyl group and triphenylsilyl group, which typically have 2 or more carbon atoms, preferably 3 or more, typically 36 or fewer, and preferably 24 or fewer; For example, siloxy groups such as trimethylsiloxy group and triphenylsiloxy group, which typically have 2 or more carbon atoms, preferably 3 or more, typically 36 or fewer, and preferably 24 or fewer; Cyano group; For example, aromatic hydrocarbon groups such as phenyl groups and naphthyl groups, which typically have 6 or more carbon atoms, typically 36 or fewer, and preferably 24 or fewer; For example, aromatic heterocyclic groups such as thienyl groups and pyridyl groups, which typically have 3 or more carbon atoms, preferably 4 or more, typically 36 or fewer, and preferably 24 or fewer.

[0243] Among the substituent group Z2 described above, the substituents are preferably alkyl groups, alkoxy groups, diarylamino groups, aromatic hydrocarbon groups, or aromatic heterocyclic groups. From the viewpoint of charge transport, aromatic hydrocarbon groups or aromatic heterocyclic groups are preferred as substituents, aromatic hydrocarbon groups are more preferred, and it is even more preferable for the substituent to be unsubstituted. From the viewpoint of improving solubility, alkyl groups or alkoxy groups are preferred as substituents.

[0244] Furthermore, each substituent in the substituent group Z2 may have further substituents. Examples of these substituents are the same as those in the substituent group Z2. Preferably, each substituent that the substituent group Z2 may have is an alkyl group having 8 or less carbon atoms, an alkoxy group having 8 or less carbon atoms, or a phenyl group, more preferably an alkyl group having 6 or less carbon atoms, an alkoxy group having 6 or less carbon atoms, or a phenyl group. From the viewpoint of charge transport, it is even more preferable that each substituent in the substituent group Z2 does not have further substituents.

[0245] <g> G represents a single bond or a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms, which may have substituents.

[0246] The number of carbon atoms in the aromatic hydrocarbon group of G is preferably 6 to 50, more preferably 6 to 30, and more preferably 6 to 18. Specific examples of aromatic hydrocarbon groups include divalent groups of aromatic hydrocarbon structures with a carbon number of typically 6 or more, typically 30 or less, preferably 18 or less, and more preferably 14 or less, such as benzene rings, naphthalene rings, anthracene rings, tetraphenylene rings, phenanthrene rings, chrysene rings, pyrene rings, benzoanthracene rings, or perylene rings, or divalent groups of structures in which multiple structures selected from these structures are linked in a chain or branched manner. When multiple aromatic hydrocarbon rings are linked, typically 2 to 8 linked rings are common, and 2 to 5 linked rings are preferred. When multiple aromatic hydrocarbon rings are linked, the same structure may be linked, or different structures may be linked.

[0247] G is preferably, single bond, Phenylene group, A divalent group in which multiple benzene rings are linked together in a chain or branched manner. A divalent group in which one or more benzene rings and at least one naphthalene ring are linked in a chain or branched manner, A divalent group in which one or more benzene rings and at least one phenanthrene ring are linked in a chain or branched manner, A divalent group in which one or more benzene rings and at least one tetraphenylene ring are linked in a chain or branched manner, More preferably, it is a divalent group in which multiple benzene rings are bonded in a chain-like or branched manner, and in either case, the order of bonding does not matter.

[0248] As mentioned above, the number of bonded benzene rings, naphthalene rings, phenanthrene rings, and tetraphenylene rings is usually 2 to 8, and preferably 2 to 5. More preferably, the structure is a divalent structure in which 1 to 4 benzene rings are linked, a divalent structure in which 1 to 4 benzene rings and a naphthalene ring are linked, a divalent structure in which 1 to 4 benzene rings and a phenanthrene ring are linked, or a divalent structure in which 1 to 4 benzene rings and a tetraphenylene ring are linked.

[0249] These aromatic hydrocarbon groups may have substituents. The substituents that the aromatic hydrocarbon groups may have are as described above, and specifically can be selected from the substituent group Z2. Preferred substituents are preferred substituents from the substituent group Z2.

[0250] <Molecular weight> The compound represented by formula (240) is a low molecular weight material, preferably with a molecular weight of 3,000 or less, more preferably 2,500 or less, even more preferably 2,000 or less, particularly preferably 1,500 or less, and usually 300 or more, preferably 350 or more, and more preferably 400 or more.

[0251] <Specific examples of compound IV represented by formula (240) above> The following are preferred specific examples of compound IV represented by formula (240), but the present invention is not limited to these.

[0252] [ka]

[0253] The light-emitting layer forming composition of the present invention may contain only one compound represented by formula (240), or it may contain two or more compounds.

[0254] [Compound: Compound represented by formula (260)] In one embodiment, the light-emitting layer forming composition of the present invention contains a compound represented by the following formula (260).

[0255] [ka]

[0256] (In formula (260), Ar 21 ~Ar 35 Each of these independently represents a hydrogen atom, an optionally substituted phenyl group, or a monovalent group consisting of 2 to 10 optionally substituted phenyl groups, either unbranched or branched and linked together.

[0257] In equation (260), Ar 21 ~Ar 35 When the phenyl group is a phenyl group which may have substituents, or a monovalent group in which 2 to 10 phenyl groups which may have substituents are linked together, either unbranched or branched, the substituents that the phenyl group may have are preferably alkyl groups.

[0258] <Alkyl alkyl group as a substituent> The alkyl group as a substituent is a linear, branched, or cyclic alkyl group having typically 1 to 12 carbon atoms, preferably 8 or fewer, more preferably 6 or fewer, and more preferably 4 or fewer carbon atoms. Specifically, examples include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, tert-butyl group, n-hexyl group, cyclohexyl group, and 2-ethylhexyl group.

[0259] In the above equation (260), Ar 21 Ar 25 Ar 26 Ar 30 Ar 31 and Ar 35 is preferably a hydrogen atom. Also, Ar 22 ~Ar 24 At least one of them is a phenyl group which may have the substituents or a monovalent group which has 2 to 10 phenyl groups which may have the substituents, either unbranched or branched and linked, and / or Ar 22 ~Ar 24 At least one of the following, and Ar 27 ~Ar 29 Preferably, at least one of the groups is a phenyl group which may have the substituents, or a monovalent group in which 2 to 10 phenyl groups which may have the substituents are linked together, either unbranched or branched. More preferably, Ar 22 ~Ar 24 Ar 27 ~Ar 29 , and Ar 32 ~Ar 34 However, it is one of the following structures: a hydrogen atom, a phenyl group, or a structure selected from formulas (261-1) to (261-9). These structures may have the substituents mentioned above, for example, they may be substituted with alkyl groups as substituents. From the viewpoint of improving solubility, substitution with alkyl groups is preferable. From the viewpoint of charge transport and durability during device operation, it is preferable that the structures do not have substituents.

[0260] [ka]

[0261] It is believed that the compound represented by formula (260) containing such a structure allows for appropriate adjustment of charge transport properties within the light-emitting layer, thereby increasing luminescence efficiency. Furthermore, it is believed that the inclusion of such a structure results in superior solubility and durability during device operation.

[0262] <Molecular weight> The compound represented by formula (260) is a low molecular weight material, preferably with a molecular weight of 3,000 or less, more preferably 2,500 or less, particularly preferably 2,000 or less, most preferably 1,500 or less, and usually 300 or more, preferably 350 or more, and more preferably 400 or more.

[0263] <Specific examples of compounds represented by formula (260)> The compounds represented by formula (260) are not particularly limited, but examples include the following compounds.

[0264] [ka]

[0265] [ka]

[0266] The light-emitting layer forming composition of the present invention may contain only one compound represented by formula (260), or it may contain two or more compounds.

[0267] [Other ingredients] The organic electroluminescent element composition of the present invention may contain, as necessary, various other solvents in addition to the solvent and light-emitting material described above. Examples of such other solvents include amides such as N,N-dimethylformamide and N,N-dimethylacetamide, and dimethyl sulfoxides.

[0268] Furthermore, the organic electroluminescent element composition of the present invention may contain various additives such as leveling agents and defoaming agents. Furthermore, when laminating two or more layers using a wet film deposition method, a photocurable resin or thermosetting resin can be included to prevent these layers from becoming incompatible, by curing them after deposition to make them insoluble.

[0269] [Mixing ratio] The solid content concentration in the composition for the organic electroluminescent element (the concentration of all solids, including the aromatic hydrocarbon compound of the present invention, the light-emitting material, the host material other than the aromatic hydrocarbon compound of the present invention, and any additional components that can be added as needed (such as leveling agents)) is usually 0.01% by mass or more, preferably 0.05% by mass or more, more preferably 0.1% by mass or more, even more preferably 0.5% by mass or more, most preferably 1% by mass or more, and usually 80% by mass or less, preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, most preferably 20% by mass or less. A solid content concentration within this range is preferable because it facilitates the formation of thin films of the desired thickness with uniform thickness.

[0270] The preferred blending ratio of the aromatic hydrocarbon compound of the present invention to the total host material contained in the light-emitting layer is as follows. Note that "total host material" refers to the aromatic hydrocarbon compound of the present invention and all host materials other than the aromatic hydrocarbon compound of the present invention.

[0271] In the organic electroluminescent element composition of the present invention, the mass ratio of the compound of the present invention to the total mass of the host material (100) is 5 or more, preferably 10 or more, more preferably 15 or more, more preferably 20 or more, particularly preferably 30 or more, and 99 or less, preferably 95 or less, even more preferably 90 or less, more preferably 80 or less, particularly preferably 70 or less.

[0272] Furthermore, in the organic electroluminescent light-emitting composition of the present invention, the molar ratio of the compound of the present invention to the total host material, that is, the molar ratio of the compound of the present invention to the total host material in the light-emitting layer, is 5 mol% or more, preferably 10 mol% or more, more preferably 20 mol% or more, more preferably 25 mol% or more, particularly preferably 30 mol% or more, 90 mol% or less, preferably 80 mol% or less, more preferably 70 mol% or less, and particularly preferably 60 mol% or less.

[0273] Furthermore, in the organic electroluminescent element composition of the present invention, the mass ratio of the light-emitting material to the total mass of the host material (100), that is, the mass ratio of the light-emitting material to the total mass of the host material in the light-emitting layer (100), is 0.1 or more, preferably 0.5 or more, more preferably 1 or more, most preferably 2 or more, and 100 or less, preferably 60 or less, more preferably 50 or less, and most preferably 40 or less. If this ratio falls below the lower limit or exceeds the upper limit, the luminous efficiency may decrease significantly.

[0274] [Method for preparing the composition] The organic electroluminescent element composition of the present invention is prepared by dissolving a solute consisting of the aromatic compound of the present invention, optionally the aforementioned light-emitting material, and various additives such as leveling agents and defoaming agents, which can be added as needed, in a suitable solvent.

[0275] To shorten the time required for the dissolution process and to maintain a uniform solute concentration in the organic electroluminescent element composition of the present invention, the solute is usually dissolved while stirring the liquid. The dissolution process may be carried out at room temperature, but if the dissolution rate is slow, it can be heated to dissolve the solute. After the dissolution process is completed, a filtration process such as filtering may be performed as needed.

[0276] [Properties, physical properties, etc. of the composition] (moisture concentration) When manufacturing an organic electroluminescent device by forming layers using a wet film deposition method with the composition of the present invention, if moisture is present in the composition, moisture will be mixed into the formed film, impairing the uniformity of the film. Therefore, it is preferable to keep the moisture content of the composition of the present invention as low as possible. In general, organic electroluminescent devices often use materials that degrade significantly due to moisture, such as the cathode. Therefore, if moisture is present in the composition, it may remain in the film after drying, potentially degrading the characteristics of the device, which is undesirable.

[0277] Specifically, the amount of water contained in the composition of the present invention is usually 1% by mass or less, preferably 0.1% by mass or less, and more preferably 0.01% by mass or less.

[0278] For measuring the water content in the composition, the method described in the Japanese Industrial Standard "Method for Measuring Water Content in Chemical Products" (JIS K0068:2001) is preferred, and analysis can be performed, for example, by the Karl Fischer reagent method (JIS K0211-1348).

[0279] (uniformity) To enhance the stability of the composition in wet film deposition processes, for example, the ejection stability from the nozzle in inkjet film deposition, it is preferable that the composition be a uniform liquid at room temperature. A uniform liquid at room temperature means that the composition is a liquid consisting of a homogeneous phase and does not contain particulate components with a particle size of 0.1 μm or larger.

[0280] (Physical properties) If the viscosity of the composition of the present invention is extremely low, problems such as uneven coating surface due to excessive liquid film flow in the film formation process, and nozzle ejection failure in inkjet film formation are more likely to occur. If the viscosity of the composition of the present invention is extremely high, problems such as nozzle clogging in inkjet film formation are more likely to occur.

[0281] Therefore, the viscosity of the composition of the present invention at 25°C is usually 2 mPa·s or more, preferably 3 mPa·s or more, more preferably 5 mPa·s or more, and usually 1000 mPa·s or less, preferably 100 mPa·s or less, and more preferably 50 mPa·s or less.

[0282] Furthermore, if the surface tension of the composition of the present invention is high, problems may occur such as reduced wettability of the film-forming solution to the substrate, poor leveling of the liquid film, and increased likelihood of surface irregularities during drying.

[0283] Therefore, the surface tension of the composition of the present invention at 20°C is usually less than 50 mN / m, preferably less than 40 mN / m.

[0284] Furthermore, if the vapor pressure of the composition of the present invention is high, problems such as changes in solute concentration due to solvent evaporation may be more likely to occur.

[0285] Therefore, the vapor pressure of the composition of the present invention at 25°C is usually 50 mmHg or less, preferably 10 mmHg or less, and more preferably 1 mmHg or less.

[0286] [Film forming method] The film formation method using the composition of the present invention is a wet film formation method. A wet film formation method is a method in which the composition is applied to form a liquid film, which is then dried to remove the organic solvent and form a film. When the composition of the present invention is a composition for an organic electroluminescent element, the organic layer of the organic electroluminescent element can be formed by a thin film formation method that includes a step of forming such a composition by a wet film formation method. Furthermore, when the composition of the present invention contains a light-emitting material, the light-emitting layer can be formed by this method. The application method can be, for example, a wet film formation method such as spin coating, dip coating, die coating, bar coating, blade coating, roll coating, spray coating, capillary coating, inkjet, nozzle printing, screen printing, gravure printing, or flexographic printing, and the coated film is dried to form the film. Among these film formation methods, spin coating, spray coating, inkjet, and nozzle printing are preferred. When manufacturing an organic EL display device equipped with an organic electroluminescent element, the inkjet method or nozzle printing method is preferred, and the inkjet method is particularly preferred.

[0287] The drying method is not particularly limited, but natural drying, vacuum drying, heat drying, or vacuum drying with heating can be used as appropriate. Heat drying may be performed after natural drying or vacuum drying to further remove residual organic solvents.

[0288] Vacuum drying is preferably performed by reducing the pressure to below the vapor pressure of the organic solvent contained in the luminescent layer forming composition.

[0289] When heating, the heating method is not particularly limited, but heating by hot plate, heating in an oven, infrared heating, etc. can be used. The heating time is usually 80°C or higher, preferably 100°C or higher, more preferably 110°C or higher, and preferably 200°C or lower, and even more preferably 150°C or lower.

[0290] The heating time is usually 1 minute or more, preferably 2 minutes or more, usually 60 minutes or less, preferably 30 minutes or less, and even more preferably 20 minutes or less.

[0291] [Electron transport layer] As described later, in an organic electroluminescent device, an electron transport layer is formed on the light-emitting layer. In the present invention, it is preferable to form the light-emitting layer with the composition of the present invention and to form the electron transport layer in contact with the light-emitting layer by a wet film deposition method.

[0292] [Composition for forming electron transport layer] The electron transport layer forming composition of the present invention comprises at least an electron transport layer material and a solvent. An alcohol-based solvent is preferred as the solvent in the electron transport layer forming composition. An electron transport material soluble in the aforementioned alcohol-based solvent is preferred as the electron transport layer material in the electron transport layer forming composition.

[0293] As the alcohol-based solvent, aliphatic alcohols with 3 or more carbon atoms are preferred. Aliphatic alcohols with 6 or more carbon atoms are even more preferred because they readily dissolve electron transport materials, have a moderately high boiling point, and readily form flat films.

[0294] Preferred aliphatic alcohol solvents include 1-butanol, isobutyl alcohol, 2-hexanol, 1,2-hexanediol, 1-hexanol, 1-heptanol, 3,5,5-trimethyl-1-hexanol, 2-methyl-2-pentanol, 4-methyl-3-heptanol, 3-methyl-2-pentanol, 4-methyl-1-pentanol, 1-nonen-3-ol, 4-heptanol, 1-methoxy-2-propanol, 3-methyl-1-pentanol, 4-octanol, 3,3-diethoxy-1-purpanol, and 3-(methylamino)-1-propanol. Two or more of these alcohols may be mixed as a solvent.

[0295] [Method for forming an electron transport layer by wet deposition] For forming the electron transport layer by wet deposition, it is preferable to use the wet deposition method described in the method for forming the light-emitting layer.

[0296] [Organic electroluminescent element] As an example of the structure of the organic electroluminescent element of the present invention, Figure 1 shows a schematic diagram (cross-section) of an example of the structure of an organic electroluminescent element 8. In Figure 1, 1 represents the substrate, 2 the anode, 3 the hole injection layer, 4 the hole transport layer, 5 the light-emitting layer, 6 the electron transport layer, and 7 the cathode.

[0297] [substrate] The substrate 1 serves as a support for the organic electroluminescent element, and is typically made of quartz, glass, metal, plastic film, or sheet. Of these, glass plates and transparent synthetic resin plates such as polyester, polymethacrylate, polycarbonate, or polysulfone are preferred. The substrate should preferably be made of a material with high gas barrier properties to prevent degradation of the organic electroluminescent element by the outside air. Therefore, especially when using a material with low gas barrier properties, such as a synthetic resin substrate, it is preferable to provide a dense silicon oxide film or the like on at least one side of the substrate to improve its gas barrier properties.

[0298] [anode] Anode 2 is responsible for injecting holes into the layer on the light-emitting layer 5 side.

[0299] Anode 2 is typically composed of metals such as aluminum, gold, silver, nickel, palladium, and platinum; metal oxides such as indium and / or tin oxides; metal halides such as copper iodide; carbon black; and conductive polymers such as poly(3-methylthiophene), polypyrrole, and polyaniline.

[0300] The formation of anode 2 is usually carried out by dry methods such as sputtering or vacuum deposition. When forming the anode using metal nanoparticles such as silver, nanoparticles such as copper iodide, carbon black, conductive metal oxide nanoparticles, or conductive polymer fine powder, it can also be formed by dispersing them in a suitable binder resin solution and coating it onto a substrate. In the case of conductive polymers, the anode can also be formed by directly forming a thin film on the substrate by electrolytic polymerization, or by coating the substrate with conductive polymer (Appl. Phys. Lett., Vol. 60, p. 2711, 1992).

[0301] Anode 2 is usually a single-layer structure, but may be a multilayer structure as appropriate. If anode 2 is a multilayer structure, different conductive materials may be laminated on the first layer of the anode.

[0302] The thickness of anode 2 can be determined according to the required transparency and material. When particularly high transparency is required, a thickness that allows for a visible light transmittance of 60% or more is preferable, and a thickness that allows for a visible light transmittance of 80% or more is even more preferable. The thickness of anode 2 is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less. On the other hand, if transparency is not required, the thickness of anode 2 can be arbitrarily set according to the required strength, etc., and in this case, anode 2 may be the same thickness as the substrate.

[0303] When depositing other layers on the surface of anode 2, it is preferable to remove impurities from anode 2 and adjust its ionization potential to improve hole injection properties by treating it with ultraviolet / ozone, oxygen plasma, argon plasma, etc., before deposition.

[0304] [Hole injection layer] The layer responsible for transporting holes from the anode 2 to the light-emitting layer 5 is usually called a hole injection transport layer or hole transport layer. When there are two or more layers responsible for transporting holes from the anode 2 to the light-emitting layer 5, the layer closer to the anode is sometimes called the hole injection layer 3. It is preferable to form the hole injection layer 3 in order to enhance the function of transporting holes from the anode 2 to the light-emitting layer 5. When forming the hole injection layer 3, it is usually formed on the anode 2.

[0305] The thickness of the hole injection layer 3 is usually 1 nm or more, preferably 5 nm or more, and usually 1000 nm or less, preferably 500 nm or less.

[0306] The hole injection layer can be formed by either vacuum deposition or wet deposition. Wet deposition is preferable because it offers superior film formation properties.

[0307] A general method for forming a hole injection layer is described below, but in the organic electroluminescent device of the present invention, it is preferable that the hole injection layer be formed by a wet film deposition method using the above-mentioned organic electroluminescent device composition.

[0308] A hole injection layer formation composition typically contains a hole transport compound for the hole injection layer, which forms the hole injection layer 3. In the case of a wet film deposition method, the hole injection layer formation composition typically also contains a solvent. It is preferable that the hole injection layer formation composition has high hole transport properties and can efficiently transport the injected holes. For this reason, it is preferable that the hole mobility is high and that impurities that act as traps are less likely to be generated during manufacturing or use. It is also preferable that it has excellent stability, a low ionization potential, and high transparency to visible light. In particular, when the hole injection layer is in contact with the light-emitting layer, it is preferable that the composition does not quench the light emission from the light-emitting layer or does not form an excyplex with the light-emitting layer to reduce the light emission efficiency.

[0309] As hole-transporting compounds for the hole injection layer, compounds having an ionization potential of 4.5 eV to 6.0 eV are preferred from the viewpoint of a charge injection barrier from the anode to the hole injection layer. Examples of such hole-transporting compounds include aromatic amine compounds, phthalocyanine compounds, porphyrin compounds, oligothiophene compounds, polythiophene compounds, benzylphenyl compounds, compounds in which tertiary amines are linked by fluorene groups, hydrazone compounds, silazane compounds, quinacridone compounds, and the like.

[0310] Among the example compounds described above, aromatic amine compounds are preferred, and aromatic tertiary amine compounds are particularly preferred, from the viewpoint of amorphousness and visible light transmittance. Here, aromatic tertiary amine compounds are compounds having an aromatic tertiary amine structure, and also include compounds having a group derived from an aromatic tertiary amine.

[0311] The type of aromatic tertiary amine compound is not particularly limited, but it is preferable to use a polymer compound (polymerized compound with repeating units) with a weight-average molecular weight of 1,000 or more and 1,000,000 or less, as this makes it easier to obtain uniform luminescence due to the surface smoothing effect.

[0312] When forming the hole injection layer 3 by a wet deposition method, a composition for film formation (hole injection layer forming composition) is usually prepared by mixing the material that will become the hole injection layer with a solvent that can dissolve it (solvent for hole injection layer). Then, this composition for hole injection layer forming is applied to the layer corresponding to the layer below the hole injection layer (usually the anode), deposited, and dried to form the hole injection layer 3.

[0313] The concentration of the hole transporting compound in the hole injection layer forming composition is arbitrary as long as it does not significantly impair the effects of the present invention. However, a lower concentration is preferable in terms of uniformity of film thickness, while a higher concentration is preferable in terms of preventing defects from forming in the hole injection layer. Specifically, it is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and particularly preferably 0.5% by mass or more. On the other hand, it is preferably 70% by mass or less, more preferably 60% by mass or less, and particularly preferably 50% by mass or less.

[0314] Examples of solvents include ether-based solvents, ester-based solvents, aromatic hydrocarbon-based solvents, and amide-based solvents.

[0315] Examples of ether-based solvents include aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA), and aromatic ethers such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenethole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, and 2,4-dimethylanisole.

[0316] Examples of ester solvents include aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate.

[0317] Examples of aromatic hydrocarbon solvents include toluene, xylene, cyclohexylbenzene, 3-isopropylbiphenyl, 1,2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene, cyclohexylbenzene, and methylnaphthalene.

[0318] Examples of amide solvents include N,N-dimethylformamide and N,N-dimethylacetamide.

[0319] In addition to these, dimethyl sulfoxide and the like can also be used.

[0320] The hole injection layer 3 is typically formed by a wet deposition method, which involves preparing a hole injection layer formation composition, coating it onto the layer below the hole injection layer 3 (usually the anode 2), and then drying it.

[0321] The hole injection layer 3 is typically dried after film formation by heating or reduced-pressure drying.

[0322] When forming the hole injection layer 3 by vacuum deposition, typically one or more of the constituent materials for the hole injection layer 3 are placed in a crucible installed inside a vacuum chamber (if more than two materials are used, each is usually placed in a separate crucible), and the inside of the vacuum chamber is vacuumed with a vacuum pump for 10°C. -4 The system is evacuated to approximately Pa. Then, the crucible is heated (if two or more materials are used, each crucible is usually heated separately) to evaporate the materials in the crucible while controlling the evaporation rate (if two or more materials are used, each is usually evaporated independently) to form a hole injection layer on the anode on the substrate placed facing the crucible. Alternatively, if two or more materials are used, a mixture of these materials can be placed in the crucible, heated, and evaporated to form the hole injection layer.

[0323] The vacuum level during deposition is not limited as long as it does not significantly impair the effects of the present invention, but is typically 0.1 × 10⁻⁶. -6 Torr(0.13×10 -4 Pa) or above, 9.0×10 -6 Torr(12.0×10 -4 The pressure is less than or equal to Pa. The deposition rate is not limited as long as it does not significantly impair the effects of the present invention, but is usually 0.1 Å / sec or more and 5.0 Å / sec or less. The deposition temperature during deposition is not limited as long as it does not significantly impair the effects of the present invention, but is preferably 10°C or more and 50°C or less.

[0324] The hole injection layer 3 may also be cross-linked in the same manner as the hole transport layer 4 described later.

[0325] [Hole transport layer] The hole transport layer 4 is a layer responsible for transporting holes from the anode 2 to the light-emitting layer 5. Although the hole transport layer 4 is not an essential layer in the organic electroluminescent device of the present invention, it is preferable to form this layer in order to enhance the function of transporting holes from the anode 2 to the light-emitting layer 5. When the hole transport layer 4 is formed, it is usually formed between the anode 2 and the light-emitting layer 5. Also, if the hole injection layer 3 described above is present, it is formed between the hole injection layer 3 and the light-emitting layer 5.

[0326] The thickness of the hole transport layer 4 is usually 5 nm or more, preferably 10 nm or more, and on the other hand, it is usually 300 nm or less, preferably 100 nm or less.

[0327] The material forming the hole transport layer 4 is preferably a material that has high hole transport properties and can efficiently transport the injected holes. For this reason, it is preferable that the material has a low ionization potential, high transparency to visible light, high hole mobility, excellent stability, and is less likely to generate trapping impurities during manufacturing or use. In addition, since the hole transport layer 4 is often in contact with the light-emitting layer 5, it is preferable that it does not quench the light emission from the light-emitting layer 5 or form an excyplex with the light-emitting layer 5, thereby reducing efficiency.

[0328] The material for such a hole transport layer 4 can be any material that has been conventionally used as a constituent material for hole transport layers, for example, those exemplified as hole transport compounds used in the hole injection layer 3 mentioned above. Other examples include arylamine derivatives, fluorene derivatives, spiro derivatives, carbazole derivatives, pyridine derivatives, pyrazine derivatives, pyrimidine derivatives, triazine derivatives, quinoline derivatives, phenanthroline derivatives, phthalocyanine derivatives, porphyrin derivatives, silole derivatives, oligothiophene derivatives, condensed polycyclic aromatic derivatives, and metal complexes.

[0329] Other examples include polyvinylcarbazole derivatives, polyarylamine derivatives, polyvinyltriphenylamine derivatives, polyfluorene derivatives, polyarylene derivatives, polyarylene ethersulfone derivatives containing tetraphenylbenzidine, polyarylenevinylene derivatives, polysiloxane derivatives, polythiophene derivatives, and poly(p-phenylenevinylene) derivatives. These may be alternating copolymers, random polymers, block polymers, or graft copolymers. They may also be polymers with branched main chains and three or more terminal ends, or so-called dendrimers.

[0330] Among these, polyarylamine derivatives and polyarylene derivatives are preferred. As polyarylamine derivatives, polymers containing repeating units represented by the following formula (II) are preferred. In particular, polymers consisting of repeating units represented by the following formula (II) are preferred, in which case, Ar a Or Ar b They may be different.

[0331] [ka]

[0332] (In formula (II), Ar a and Ar b Each of these independently represents an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group.

[0333] Examples of polyarylene derivatives include polymers having arylene groups as repeating units, such as aromatic hydrocarbon groups or aromatic heterocyclic groups that may have substituents.

[0334] As polyarylene derivatives, polymers having repeating units consisting of the following formula (III-1) and / or formula (III-2) are preferred.

[0335] [ka]

[0336] (In formula (III-1), R a , R b , R c and R d Each independently represents an alkyl group, alkoxy group, phenylalkyl group, phenylalkoxy group, phenyl group, phenoxy group, alkylphenyl group, alkoxyphenyl group, alkylcarbonyl group, alkoxycarbonyl group, or carboxyl group. Each independently represents an integer from 0 to 3. If t or s is 2 or more, multiple R groups are contained in one molecule. a or R b They may be the same or different, and adjacent R a or R b They may form a ring with each other.

[0337] [ka]

[0338] (In formula (III-2), R e and R f Each of these independently corresponds to R in equation (III-1) above. a , R b , R c or R d This is synonymous. r and u each independently represent integers from 0 to 3. If r or u is 2 or greater, multiple R's are contained within a single molecule. e and R f They may be the same or different, and adjacent R e or R f They may form a ring with each other. (X represents an atom or group of atoms constituting a 5-membered ring or a 6-membered ring.)

[0339] Specific examples of X include an oxygen atom, a optionally substituted boron atom, a optionally substituted nitrogen atom, a optionally substituted silicon atom, a optionally substituted phosphorus atom, a optionally substituted sulfur atom, a optionally substituted carbon atom, or a group formed by bonding these atoms.

[0340] Furthermore, as a polyarylene derivative, it is preferable to have a repeating unit represented by the following formula (III-3) in addition to the repeating unit consisting of formula (III-1) and / or formula (III-2) above.

[0341] [ka]

[0342] (In formula (III-3), Ar c ~Ar i Each independently represents an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group. v and w each independently represent 0 or 1.

[0343] Specific examples of the above formulas (III-1) to (III-3) and specific examples of polyarylene derivatives are described in Japanese Patent Publication No. 2008-98619, among others.

[0344] When forming the hole transport layer 4 by a wet film deposition method, the hole transport layer forming composition is prepared in the same manner as for forming the hole injection layer 3, followed by wet film deposition and then heat drying.

[0345] The hole transport layer formation composition contains a solvent in addition to the hole transport compound described above. The solvent used is the same as that used in the hole injection layer formation composition. The film formation conditions, heating and drying conditions, etc., are also the same as those for the formation of hole injection layer 3.

[0346] When forming a hole transport layer by vacuum deposition, the film deposition conditions are the same as those for forming the hole injection layer 3 described above.

[0347] The hole transport layer 4 may contain, in addition to the hole transport compound mentioned above, various light-emitting materials, electron transport compounds, binder resins, coating property modifiers, and the like.

[0348] Furthermore, the hole transport layer 4 may be a layer formed by crosslinking a crosslinkable compound. The crosslinkable compound is a compound having a crosslinkable group, and by crosslinking, it forms a network polymer compound.

[0349] Examples of these crosslinkable groups include groups derived from cyclic ethers such as oxetanes and epoxy; groups derived from unsaturated double bonds such as vinyl groups, trifluorovinyl groups, styryl groups, acrylic groups, methacryloyl, and cinnamoyl; and groups derived from benzocyclobutene.

[0350] The crosslinkable compound may be a monomer, oligomer, or polymer. The crosslinkable compound may consist of only one type, or two or more types in any combination and ratio.

[0351] As the crosslinkable compound, it is preferable to use a hole-transporting compound having a crosslinkable group. Examples of hole-transporting compounds include those exemplified above, and as the crosslinkable compound, it is preferable that the crosslinkable group is bonded to the main chain or side chain of these hole-transporting compounds. In particular, it is preferable that the crosslinkable group is bonded to the main chain via a linking group such as an alkylene group. Furthermore, as the hole-transporting compound, it is preferable that it is a polymer containing repeating units having a crosslinkable group, and it is preferable that it is a polymer having repeating units to which the crosslinkable group is directly or via a linking group to formula (II) or formulas (III-1) to (III-3) above.

[0352] To form a hole transport layer 4 by crosslinking a crosslinkable compound, a hole transport layer forming composition is usually prepared by dissolving or dispersing the crosslinkable compound in a solvent, and then the film is formed and crosslinked by wet deposition.

[0353] The thickness of the hole transport layer 4 formed in this manner is usually 5 nm or more, preferably 10 nm or more, and usually 300 nm or less, preferably 100 nm or less.

[0354] [Luminous layer] The light-emitting layer 5 is a layer that is excited and emits light when an electric field is applied between a pair of electrodes, by the recombination of holes injected from the anode 2 and electrons injected from the cathode 7. The light-emitting layer 5 is formed between the anode 2 and the cathode 7. If there is a hole injection layer above the anode, the light-emitting layer is formed between the hole injection layer and the cathode. If there is a hole transport layer above the anode, the light-emitting layer is formed between the hole transport layer and the cathode.

[0355] As described above, the organic electroluminescent device in the present invention preferably includes the aromatic compound and light-emitting material of the present invention as the light-emitting layer.

[0356] The film thickness of the light-emitting layer 5 is arbitrary as long as it does not significantly impair the effects of the present invention. However, a thicker film is preferable in that defects are less likely to occur in the film, while a thinner film is preferable in that it is easier to achieve a low driving voltage. For this reason, it is preferably 3 nm or more, more preferably 5 nm or more, and usually preferably 200 nm or less, and even more preferably 100 nm or less.

[0357] The light-emitting layer 5 contains at least a material having light-emitting properties (light-emitting material), and preferably contains one or more host materials.

[0358] [Hole Blocking Layer] A hole-blocking layer may be provided between the light-emitting layer 5 and the electron injection layer described later. The hole-blocking layer is a layer laminated on top of the light-emitting layer 5 so as to be in contact with the interface of the light-emitting layer 5 on the cathode 7 side.

[0359] This hole-blocking layer has two roles: preventing holes moving from anode 2 from reaching cathode 7, and efficiently transporting electrons injected from cathode 7 towards the light-emitting layer 5. The required properties for the material constituting the hole-blocking layer include high electron mobility and low hole mobility, a large energy gap (difference between HOMO and LUMO), and a high excited triplet level (T1).

[0360] Examples of hole blocking layer materials that satisfy these conditions include mixed ligand complexes such as bis(2-methyl-8-quinolinolato)(phenolato)aluminum and bis(2-methyl-8-quinolinolato)(triphenylsilanolato)aluminum, metal complexes such as bis(2-methyl-8-quinolato)aluminum-μ-oxo-bis-(2-methyl-8-quinolinolato)aluminum dinuclear metal complexes, styryl compounds such as distyrylbiphenyl derivatives (Japanese Patent Publication No. 11-242996), triazole derivatives such as 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (Japanese Patent Publication No. 7-41759), and phenanthroline derivatives such as basocproine (Japanese Patent Publication No. 10-79297). Furthermore, compounds having at least one pyridine ring substituted at the 2,4, and 6 positions, as described in International Publication No. 2005 / 022962, are also preferred as materials for hole blocking layers.

[0361] There are no restrictions on the method of forming the hole blocking layer. Therefore, it can be formed by wet deposition, vapor deposition, or other methods.

[0362] The thickness of the hole blocking layer is arbitrary as long as it does not significantly impair the effects of the present invention, but is usually 0.3 nm or more, preferably 0.5 nm or more, and is usually 100 nm or less, preferably 50 nm or less.

[0363] [Electron transport layer] The electron transport layer 6 is provided between the light-emitting layer 5 and the cathode 7 with the aim of further improving the current efficiency of the device.

[0364] The electron transport layer 6 is formed from a compound that can efficiently transport electrons injected from the cathode 7 towards the light-emitting layer 5 between electrodes under an applied electric field. The electron transport compound used in the electron transport layer 6 must have high electron injection efficiency from the cathode 7, high electron mobility, and be able to efficiently transport the injected electrons.

[0365] Examples of electron-transporting compounds used in the electron transport layer include, for example, metal complexes such as aluminum complexes of 8-hydroxyquinoline (Japanese Patent Publication No. 59-194393), metal complexes of 10-hydroxybenzo[h]quinoline, oxadiazole derivatives, distyrylbiphenyl derivatives, silole derivatives, 3-hydroxyflavone metal complexes, 5-hydroxyflavone metal complexes, benzoxazole metal complexes, benzothiazole metal complexes, trisbenzimidazolbenzene (U.S. Patent No. 5645948), quinoxaline compounds (Japanese Patent Publication No. 6-207169), phenanthroline derivatives (Japanese Patent Publication No. 5-331459), 2-tert-butyl-9,10-N,N'-dicyanoanthraquinone diimine, n-type hydrogenated amorphous silicon carbide, n-type zinc sulfide, n-type zinc selenide, and the like.

[0366] The film thickness of the electron transport layer 6 is usually 1 nm or more, preferably 5 nm or more, and usually 300 nm or less, preferably 100 nm or less.

[0367] The electron transport layer 6 is formed by laminating it onto the hole blocking layer using either a wet deposition method or a vacuum deposition method, as described above. Vacuum deposition is typically used. In the present invention, as described above, an electron transport layer can be formed on the light-emitting layer containing the aromatic compound of the present invention by a wet film deposition method.

[0368] [Electron injection layer] An electron injection layer may be provided to efficiently inject electrons injected from the cathode 7 into the electron transport layer 6 or the light-emitting layer 5.

[0369] To efficiently perform electron injection, the material forming the electron injection layer is preferably a metal with a low work function. Examples include alkali metals such as sodium and cesium, and alkaline earth metals such as barium and calcium. The film thickness is usually preferably between 0.1 nm and 5 nm.

[0370] Furthermore, doping organic electron transport materials, such as nitrogen-containing heterocyclic compounds like bathophenanthroline and metal complexes like aluminum complexes of 8-hydroxyquinoline, with alkali metals such as sodium, potassium, cesium, lithium, and rubidium (as described in Japanese Patent Publication No. 10-270171, Japanese Patent Publication No. 2002-100478, Japanese Patent Publication No. 2002-100482, etc.) is also preferable because it improves electron injection and transport properties and enables the achievement of excellent film quality.

[0371] The thickness of the electron injection layer is typically 5 nm or more, preferably 10 nm or more, and typically 200 nm or less, preferably 100 nm or less.

[0372] The electron injection layer is formed by laminating it onto the light-emitting layer 5 or the hole-blocking layer or electron transport layer 6 located thereon, using a wet deposition method or a vacuum deposition method. The details for the wet film deposition method are the same as those for the luminescent layer described above.

[0373] In some cases, the hole blocking layer, electron transport layer, and electron injection layer are combined into a single layer by co-doping the electron transport material with a lithium complex.

[0374] [cathode] The cathode 7 plays the role of injecting electrons into the layer on the light-emitting layer 5 side (such as the electron injection layer or light-emitting layer).

[0375] As the material for the cathode 7, the same material used for the anode 2 can be used. However, for efficient electron injection, it is preferable to use a metal with a low work function. For example, metals such as tin, magnesium, indium, calcium, aluminum, and silver, or alloys thereof, can be used. Specific examples include low-work-function alloy electrodes such as magnesium-silver alloys, magnesium-indium alloys, and aluminum-lithium alloys.

[0376] In terms of the stability of organic electroluminescent devices, it is preferable to protect the cathode, which is made of a metal with a low work function, by laminating a metal layer with a high work function and stability to the atmosphere on top of the cathode. Examples of metals that can be laminated include aluminum, silver, copper, nickel, chromium, gold, and platinum.

[0377] The film thickness of the cathode is usually the same as that of the anode.

[0378] [Other layers] The organic electroluminescent element of the present invention may have other layers as long as they do not significantly impair the effects of the present invention. That is, it may have any other layer between the anode and the cathode as described above.

[0379] [Other component configurations] The organic electroluminescent element of the present invention can also have a structure reversed from the above description, that is, for example, stacked on a substrate in the order of cathode, electron injection layer, electron transport layer, hole blocking layer, light-emitting layer, hole transport layer, hole injection layer, and anode.

[0380] When applying the organic electroluminescent element of the present invention to an organic electroluminescent device, it may be used as a single organic electroluminescent element, in a configuration in which multiple organic electroluminescent elements are arranged in an array, or in a configuration in which the anode and cathode are arranged in an XY matrix.

[0381] [Manufacturing method for organic electroluminescent element] The present invention provides a method for manufacturing an organic electroluminescent element, using the above-described composition for organic electroluminescent elements. The organic electroluminescent element may, for example, have an anode and a cathode on a substrate, with an organic layer between the anode and the cathode.

[0382] One embodiment of the method for manufacturing an organic electroluminescent element of the present invention may include a step of forming the organic layer by a wet film deposition method using the above-described organic electroluminescent element composition. The organic layer may be, for example, an emissive layer.

[0383] In another embodiment of the method for manufacturing an organic electroluminescent element of the present invention, the organic layer comprises an emissive layer and an electron transport layer, and the method may include, in this order, the steps of: forming the emissive layer by a wet deposition method using the above-described organic electroluminescent element composition; and forming the electron transport layer by a wet deposition method using an electron transport layer composition containing an electron transport material and a solvent. The solvent contained in the electron transport layer composition may be an alcohol-based solvent. Furthermore, the electron transport layer formed by the wet deposition method may be formed so as to be directly laminated onto the emissive layer formed by the wet deposition method.

[0384] <Organic EL display device> The organic EL display device (organic electroluminescent element display device or display device) of the present invention comprises the organic electroluminescent element of the present invention. There are no particular restrictions on the type or structure of the organic EL display device of the present invention, and it can be assembled according to conventional methods using the organic electroluminescent element of the present invention.

[0385] For example, the organic EL display device of the present invention can be formed by a method such as that described in "Organic EL Display" (Ohmsha, published August 20, 2004, authored by Shizuka Tokito, Chihaya Adachi, and Hideyuki Murata).

[0386] <Organic EL lighting> The organic EL lighting (organic electroluminescent element lighting or lighting device) of the present invention comprises the organic electroluminescent element of the present invention. There are no particular restrictions on the type or structure of the organic EL lighting of the present invention, and it can be assembled according to conventional methods using the organic electroluminescent element of the present invention. [Examples]

[0387] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the invention. The various conditions and evaluation result values ​​in the following examples are meant as preferred upper or lower limits in the embodiments of the present invention, and the preferred range may be defined by a combination of the aforementioned upper or lower limits and the values ​​in the following examples or between examples.

[0388] In this specification, Ac means acetyl group, Ph means phenyl group, dppf means 1,1'-bis(diphenylphosphin)ferrocene, and DMSO means dimethyl sulfoxide. Compound 1-g and comparative compound (C-1) were synthesized according to the method described in Patent Document 1 (International Publication No. 2012 / 137958).

[0389] <Synthesis Example 1: Synthesis Example of Compound (H-1)> (Synthesis of compound 1-c)

[0390] [ka]

[0391] Compound 1-a (15.0 g, 41.6 mmol) and compound 1-b (14.9 g, 41.6 mmol) were sequentially added to toluene (100 mL) bubbling with nitrogen, ethanol (50 mL), and tripotassium phosphate aqueous solution (2.0 mol / L, 50 mL), and the mixture was heated to 50°C. Then, PdCl2(PPh3)2 (0.29 g, 0.41 mmol) was added, and the mixture was stirred at 65°C for 2 hours. After cooling to room temperature, saturated sodium chloride aqueous solution was added, and extraction was performed using toluene. The organic layer was washed with saturated sodium chloride aqueous solution, dried over magnesium sulfate, and the solvent was removed under reduced pressure. The residue was subjected to silica gel column chromatography to obtain compound 1-c (yield 21.6 g, 95%).

[0392] (Synthesis of compound 1-d)

[0393] [ka]

[0394] Compound 1-c (21.6 g, 39.5 mmol), bis(pinacolatodiborone) (15.0 g, 59.2 mmol), and potassium acetate (11.6 g, 118.5 mmol) were mixed with anhydrous DMSO (200 mL) and heated to 50°C. PdCl2(dppf)CH2Cl2 (1.61 g, 1.98 mmol) was added and the mixture was stirred at 90°C for 3 hours. After cooling to room temperature, distilled water was added and the mixture was filtered by suction. The filtered material was dissolved in toluene, washed with saturated sodium chloride aqueous solution, dried over magnesium sulfate, and the solvent was removed under reduced pressure. The residue was subjected to silica gel column chromatography to obtain compound 1-d (yield 20.5 g, yield 87%).

[0395] (Synthesis of compound 1-e)

[0396] [ka]

[0397] Compound 1-d (20.5 g, 34.4 mmol) and 1-bromo-4-iodobenzene (9.75 g, 34.4 mmol) were sequentially added to toluene (100 mL) bubbling with nitrogen, ethanol (50 mL), and tripotassium phosphate aqueous solution (2.0 mol / L, 50 mL), and the mixture was heated to 50°C. Then, PdCl2(PPh3)2 (0.24 g, 0.34 mmol) was added, and the mixture was stirred at 65°C for 2 hours. After cooling to room temperature, saturated sodium chloride aqueous solution was added, and extraction was performed using toluene. The organic layer was washed with saturated sodium chloride aqueous solution, dried over magnesium sulfate, and the solvent was removed under reduced pressure. The residue was subjected to silica gel column chromatography to obtain compound 1-e (yield 17.8 g, 83%).

[0398] (Synthesis of compound 1-f)

[0399] [ka]

[0400] Compound 1-e (16.8 g, 26.9 mmol), bis(pinacolatodiborone) (10.3 g, 40.4 mmol), and potassium acetate (7.92 g, 80.7 mmol) were mixed with anhydrous DMSO (200 mL) and heated to 50°C. PdCl2(dppf)CH2Cl2 (1.10 g, 1.35 mmol) was added and the mixture was stirred at 90°C for 2 hours. After cooling to room temperature, distilled water was added and the mixture was filtered by suction. The filtered material was dissolved in toluene, washed with saturated sodium chloride aqueous solution, dried over magnesium sulfate, and the solvent was removed under reduced pressure. The residue was subjected to silica gel column chromatography to obtain compound 1-f (yield 16.2 g, 90%).

[0401] (Synthesis of compound (H-1))

[0402] [ka]

[0403] Under a nitrogen atmosphere, compound 1-f (7.8 g, 11.7 mmol) and compound 1-g (7.7 g, 10.6 mmol) were sequentially added to THF (50 mL) that had been bubbling with nitrogen, and then to a tripotassium phosphate aqueous solution (2.0 mol / L, 15 mL). Subsequently, Pd(PPh3)4 (0.12 g, 0.11 mmol) was added, and the mixture was heated and stirred at 75°C for 4 hours. After cooling to room temperature, saturated sodium chloride aqueous solution and 1N dilute hydrochloric acid were added, and extraction was performed using dichloromethane. The organic layer was washed with saturated sodium chloride aqueous solution, dried over magnesium sulfate, and the solvent was removed under reduced pressure. The residue was subjected to silica gel column chromatography to obtain compound (H-1) (yield 10.7 g, yield 81%).

[0404] <Synthesis Example 2: Synthesis Example of Compound (H-2)> (Synthesis of compound 2-b)

[0405] [ka]

[0406] Under a nitrogen atmosphere, compound 2-a (19.6 g, 50.9 mmol) was added to anhydrous THF (100 mL) and cooled to -75°C. Then, n-BuLi (1.58 mol / L, 32.2 mL) was added dropwise, and the mixture was stirred at -75°C for 3 hours. The prepared solution was added dropwise to an anhydrous THF (100 mL) solution of cyanuric chloride (18.8 g, 101.8 mmol) cooled to -100°C. After raising the temperature to room temperature, saturated sodium chloride aqueous solution and 1N dilute hydrochloric acid were added, and extraction was performed using ethyl acetate. The organic layer was washed with saturated sodium chloride aqueous solution, dried over magnesium sulfate, and the solvent was removed under reduced pressure. The residue was subjected to silica gel column chromatography to obtain compound 2-b (yield 6.5 g, yield 28%).

[0407] (Synthesis of compound 2-d)

[0408] [ka]

[0409] Under a nitrogen atmosphere, compound 2-b (4.7 g, 10.3 mmol) and compound 2-c (4.5 g, 10.3 mmol) were sequentially added to THF (100 mL) that had been bubbling with nitrogen, and then to a tripotassium phosphate aqueous solution (2.0 mol / L, 13 mL). Subsequently, Pd(PPh3)4 (0.12 g, 0.10 mmol) was added, and the mixture was heated and stirred at 55°C for 8 hours. After cooling to room temperature, saturated sodium chloride aqueous solution and 1N dilute hydrochloric acid were added, and extraction was performed using dichloromethane. The organic layer was washed with saturated sodium chloride aqueous solution, dried over magnesium sulfate, and the solvent was removed under reduced pressure. The residue was subjected to silica gel column chromatography to obtain compound 2-d (yield 4.9 g, yield 66%).

[0410] (Synthesis of compound 2-g)

[0411] [ka]

[0412] Under a nitrogen atmosphere, compound 2-e (3.3 g, 9.28 mmol) and compound 2-f (3.6 g, 9.28 mmol) were sequentially added to toluene (40 mL), ethanol (20 mL), and tripotassium phosphate aqueous solution (2.0 mol / L, 20 mL) that had been bubbling with nitrogen. Then, Pd(PPh3)4 (0.11 g, 0.093 mmol) was added, and the mixture was heated and stirred at 90°C for 4 hours. After cooling to room temperature, saturated sodium chloride aqueous solution was added, and extraction was performed using toluene. The organic layer was washed with saturated sodium chloride aqueous solution, dried over magnesium sulfate, and the solvent was removed under reduced pressure. The residue was subjected to silica gel column chromatography to obtain compound 2-g (yield 2.6 g, yield 45%).

[0413] (Synthesis of compound 2-h)

[0414] [ka]

[0415] Compound 2-g (2.6g, 4.17 mmol), bis(pinacolatodiborone) (1.6g, 6.25 mmol), and potassium acetate (1.2g, 12.5 mmol) were mixed with anhydrous DMSO (50 mL) and heated to 50°C. PdCl2(dppf)CH2Cl2 (0.17g, 0.21 mmol) was added, and the mixture was stirred at 90°C for 7 hours. After cooling to room temperature, distilled water was added, and the mixture was filtered by suction. The filtered material was dissolved in dichloromethane, washed with saturated sodium chloride aqueous solution, dried over magnesium sulfate, and the solvent was removed under reduced pressure. The residue was subjected to silica gel column chromatography to obtain compound 2-h (yield 0.89 g, yield 32%).

[0416] (Synthesis of compound (H-2))

[0417] [ka]

[0418] Under a nitrogen atmosphere, compound 2-d (0.64 g, 0.88 mmol) and compound 2-h (0.59 g, 0.88 mmol) were sequentially added to THF (30 mL) that had been bubbling with nitrogen, and tripotassium phosphate aqueous solution (2.0 mol / L, 3 mL). Then, Pd(PPh3)4 (10 mg, 0.0088 mmol) was added, and the mixture was heated and stirred at 70°C for 5 hours. After cooling to room temperature, saturated sodium chloride aqueous solution and 1N dilute hydrochloric acid were added, and extraction was performed using dichloromethane. The organic layer was washed with saturated sodium chloride aqueous solution, dried over magnesium sulfate, and the solvent was removed under reduced pressure. The residue was subjected to silica gel column chromatography to obtain compound (H-2) (yield 0.69 g, yield 64%).

[0419] <Example of compound (H-3) synthesis> (Synthesis of compound 3-b)

[0420] [ka]

[0421] Under a nitrogen atmosphere, compound 3-a (22.1 g, 57.3 mmol) was added to anhydrous THF (100 mL) and cooled to -75°C. Then, n-BuLi (1.58 mol / L, 36.3 mL) was added dropwise, and the mixture was stirred at -75°C for 3 hours. The prepared solution was added dropwise to an anhydrous THF (100 mL) solution of cyanuric chloride (4.75 g, 25.8 mmol) cooled to -100°C. After raising the temperature to room temperature, saturated sodium chloride aqueous solution and 1N dilute hydrochloric acid were added, and extraction was performed using ethyl acetate. The organic layer was washed with saturated sodium chloride aqueous solution, dried over magnesium sulfate, and the solvent was removed under reduced pressure. The residue was subjected to silica gel column chromatography to obtain compound 3-b (yield 5.5 g, yield 29%).

[0422] (Synthesis of compound (H-3))

[0423] [ka]

[0424] Under a nitrogen atmosphere, compound 3-b (0.85 g, 1.18 mmol) and compound 2-h (0.79 g, 1.18 mmol) were sequentially added to THF (30 mL) that had been bubbling with nitrogen, and tripotassium phosphate aqueous solution (2.0 mol / L, 10 mL). Then, Pd(PPh3)4 (60 mg, 0.012 mmol) was added, and the mixture was heated and stirred at 70°C for 3 hours. After cooling to room temperature, saturated sodium chloride aqueous solution and 1N dilute hydrochloric acid were added, and extraction was performed using dichloromethane. The organic layer was washed with saturated sodium chloride aqueous solution, dried over magnesium sulfate, and the solvent was removed under reduced pressure. The residue was subjected to silica gel column chromatography to obtain compound (H-3) (yield 0.72 g, yield 50%).

[0425] (Synthesis of comparative compound (C-2))

[0426] [ka]

[0427] Under a nitrogen atmosphere, compound C2-a (1.16 g, 2.49 mmol) and compound C2-b (0.89 g, 2.49 mmol) were sequentially added to THF (15 mL) that had been bubbling with nitrogen, and tripotassium phosphate aqueous solution (2.0 mol / L, 5 mL). Then, Pd(PPh3)4 (29 mg, 0.025 mmol) was added, and the mixture was heated and stirred at 70°C for 5 hours. After cooling to room temperature, saturated sodium chloride aqueous solution and 1N dilute hydrochloric acid were added, and extraction was performed using dichloromethane. The organic layer was washed with saturated sodium chloride aqueous solution, dried over magnesium sulfate, and the solvent was removed under reduced pressure. The residue was subjected to silica gel column chromatography to obtain comparative compound (C-2) (yield 1.0 g, yield 60%).

[0428] (Synthesis of comparative compound (C-3))

[0429] [ka]

[0430] Under a nitrogen atmosphere, compound C3-a (1.15 g, 2.74 mmol) and compound C3-b (1.18 g, 3.29 mmol) were sequentially added to THF (20 mL) that had been bubbling with nitrogen, and tripotassium phosphate aqueous solution (2.0 mol / L, 6 mL). Then, Pd(PPh3)4 (32 mg, 0.027 mmol) was added, and the mixture was heated and stirred at 70°C for 5 hours. After cooling to room temperature, the solid was filtered. The filtered material was washed with methanol, acetone, and dichloromethane, and dried under reduced pressure to obtain comparative compound (C-3) (yield 1.3 g, yield 68%).

[0431] <Evaluation of compounds (H-1) to (H-3) and comparative compound (C-1)> The glass transition temperature (Tg) of each compound was evaluated by differential scanning calorimetry (DSC). The ionization potential (Ip) of each compound was evaluated by photoelectron spectroscopy. The electron affinity (Ea) of each compound was calculated by subtracting Ip from the band gap (Eg) calculated from the absorption edge of the absorption spectrum. The results are shown in Table 1.

[0432] [Table 1]

[0433] The comparative compounds (C-1) to (C-3) used were those listed below.

[0434] <Evaluation of solubility of compounds (H-1) to (H-3) and comparative compounds (C-1) to (C-3)> Furthermore, to evaluate the solubility of each compound in cyclohexylbenzene (CHB), 1-2 mL of cyclohexylbenzene solution (concentration of each compound: 12.0% by mass) was prepared, and it was evaluated whether or not each compound dissolved in the solution. The results are shown in Table 2. In the column "12.0% by mass CHB solution" in Table 2, "○" means that the compound dissolved in the solution, and "×" means that the compound did not dissolve in the solution.

[0435] The compounds (H-1) to (H-3) of the present invention and the comparative compound (C-2) exhibited solubility of 12.0% by mass or more in CHB.

[0436] [Table 2]

[0437] [ka]

[0438] <Evaluation of solvent resistance of compound (H-1) to (H-2) and comparative compound (C-1) after film formation> The solvent resistance of each compound after film formation was evaluated as follows. First, a solution was prepared by dissolving the compound to be tested in toluene at a concentration of 1.5% by mass. This solution was dropped onto a glass substrate in a nitrogen glove box and spin-coated, and then dried on a hot plate at 100°C for 10 minutes to form a film of the compound to be tested.

[0439] Next, the substrate on which the compound film was deposited was placed in a spin coater, 150 μl of the test solvent was dropped onto the substrate, and the substrate was left to stand for 60 seconds after dropping to perform the solvent resistance test.

[0440] Subsequently, the substrate was rotated at 1500 rpm for 30 seconds, and then at 4000 rpm for 30 seconds to spin out the dropped solvent. This substrate was dried on a hot plate at 100°C for 10 minutes. The change in film thickness before and after the solvent resistance test was estimated from the difference in film thickness. The film thickness after deposition of each compound and the test solvent used are as follows:

[0441] (Compound (H-1)) A 54 nm film was formed using the compound (H-1) of the present invention, and a solvent resistance test was conducted using 1-butanol as the test solvent.

[0442] (Compound (H-2)) A 54 nm film was formed using the compound (H-2) of the present invention, and a solvent resistance test was conducted using 1-butanol as the test solvent.

[0443] (Comparative compound (C-1)) A 54 nm film was formed using comparative compound (C-1), and a solvent resistance test was conducted using 1-butanol as the test solvent.

[0444] The solvent resistance of the compound after film formation was evaluated based on the following criteria. ○: No reduction in film thickness was observed. ×: A reduction in film thickness of 5 nm or more was observed. The results of the solvent resistance test are shown in Table 3.

[0445] [Table 3]

[0446] [Example 1] Organic electroluminescent devices were fabricated using the following method. A transparent conductive film of indium tin oxide (ITO) was deposited to a thickness of 50 nm on a glass substrate (Geomatec Co., Ltd., sputter-deposited product). This film was then patterned into 2 mm wide stripes using conventional photolithography techniques and hydrochloric acid etching to form an anode. The substrate with the ITO pattern was then cleaned in the following order: ultrasonic cleaning with a surfactant aqueous solution, rinsing with ultrapure water, ultrasonic cleaning with ultrapure water, and rinsing with ultrapure water. After drying with compressed air, the substrate was finally cleaned with ultraviolet ozone. As a composition for forming a hole injection layer, a composition was prepared by dissolving 3.0% by weight of a hole-transporting polymer compound having a repeating structure of the following formula (P-1) and 0.6% by weight of an electron-accepting compound (HI-1) in ethyl benzoate.

[0447] [ka]

[0448] This solution was spin-coated onto the substrate in air, dried on a hot plate at 240°C for 30 minutes in air to form a uniform thin film with a thickness of 40 nm, which served as the hole injection layer. Next, a charge-transporting polymer compound having the following structural formula (HT-1) was dissolved in 1,3,5-trimethylbenzene to prepare a 2.0% by weight solution. This solution was spin-coated onto a substrate coated with the hole injection layer in a nitrogen glove box, and dried on a hot plate in the nitrogen glove box at 230°C for 30 minutes to form a uniform thin film with a thickness of 40 nm, which served as the hole transport layer.

[0449] [ka]

[0450] Subsequently, as a material for the light-emitting layer, a composition for forming a light-emitting layer was prepared by dissolving the compound (H-1) of the present invention in 2.3% by weight, the compound (HH-1) having the following structure in 2.3% by weight, and (D-1) in 1.4% by weight in cyclohexylbenzene.

[0451] [ka]

[0452] This solution was spin-coated onto a substrate coated with the hole transport layer in a nitrogen glove box, and dried on a hot plate in the nitrogen glove box at 120°C for 20 minutes to form a uniform thin film with a thickness of 40 nm, which served as the light-emitting layer. A substrate with the light-emitting layer deposited is placed in a vacuum deposition apparatus, and the inside of the apparatus is 2 × 10 -4 The exhaust was vented until the pressure dropped below Pa. Next, the following structural formula (ET-1) and 8-hydroxyquinolinolatritium were co-deposited onto the light-emitting layer in a film thickness ratio of 2:3 using vacuum deposition to form an electron transport layer with a film thickness of 30 nm.

[0453] [ka]

[0454] Next, a 2 mm wide striped shadow mask was placed in close contact with the substrate as a mask for cathode deposition, perpendicular to the ITO stripe of the anode. The aluminum was then heated using a molybdenum boat to form an aluminum layer with a thickness of 80 nm, thereby forming the cathode. In this way, an organic electroluminescent device having an emitting area of ​​2 mm × 2 mm was obtained.

[0455] [Example 2] An organic electroluminescent device was fabricated in the same manner as in Example 1, except that compound (H-2) of the present invention was used instead of compound (H-1) as the material for the light-emitting layer.

[0456] [Example 3] An organic electroluminescent device was fabricated in the same manner as in Example 1, except that compound (H-3) of the present invention was used instead of compound (H-1) as the material for the light-emitting layer.

[0457] [Comparative Example 1] An organic electroluminescent device was fabricated in the same manner as in Example 1, except that a comparative compound (C-2) was used instead of compound (H-1) as the material for the light-emitting layer.

[0458] [Evaluation of the element] The organic electroluminescent elements obtained in Examples 1-3 and Comparative Example 1 were subjected to a 1,000 cd / m² test. 2 The current efficiency (cd / A) and external quantum efficiency (%) were measured when the light was emitted using the device. Additionally, 15 mA / cm² was measured. 2 When the element was continuously energized at the specified current density, the time (LT95) at which the brightness decreased to 95% of the initial brightness was measured. These measurement results are shown in Table 4. In Table 4, the values ​​for Examples 1 to 3 are relative values ​​with the value of Comparative Example 1 set to 1. From the results in Table 4, it was found that the performance of the organic electroluminescent element using the compound of the present invention was improved.

[0459] [Table 4]

[0460] [Example 4] An organic electroluminescent device was fabricated in the same manner as in Example 1, except that the light-emitting layer was formed as shown below. As a material for the light-emitting layer, a composition for forming the light-emitting layer was prepared by dissolving compound (H-1) at a concentration of 2.7% by weight, compound (HH-2) at a concentration of 2.7% by weight, and compound (D-1) at a concentration of 1.6% by weight in cyclohexylbenzene.

[0461] [ka]

[0462] The light-emitting layer formation composition was spin-coated onto a substrate on which the hole transport layer had been deposited in a nitrogen glove box, and dried on a hot plate in the nitrogen glove box at 120°C for 20 minutes to form a uniform thin film with a thickness of 70 nm, which served as the light-emitting layer.

[0463] [Example 5] An organic electroluminescent device was fabricated in the same manner as in Example 4, except that compound (H-2) of the present invention was used instead of compound (H-1) as the material for the light-emitting layer.

[0464] [Example 6] An organic electroluminescent device was fabricated in the same manner as in Example 4, except that compound (H-3) of the present invention was used instead of compound (H-1) as the material for the light-emitting layer.

[0465] [Comparative Example 2] An organic electroluminescent device was fabricated in the same manner as in Example 4, except that a comparative compound (C-2) was used instead of compound (H-1) as the material for the light-emitting layer.

[0466] [Evaluation of the element] The organic electroluminescent elements obtained in Examples 4-6 and Comparative Example 2 were subjected to a 1,000 cd / m² test. 2 The current efficiency (cd / A) and external quantum efficiency (%) were measured when the light was emitted using the device. Additionally, 15 mA / cm² was measured. 2 When the element was continuously energized at the specified current density, the time (LT97) at which the brightness decreased to 97% of the initial brightness was measured. These measurement results are shown in Table 5. In Table 5, the values ​​for Examples 4 to 6 are relative values ​​with the value of Comparative Example 2 set to 1. From the results in Table 5, it was found that the performance of the organic electroluminescent element using the compound of the present invention was improved.

[0467] [Table 5]

[0468] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present invention is not limited to these examples. It is clear to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of the present invention. Furthermore, the components of the above embodiments may be combined in any way without departing from the spirit of the invention.

[0469] This application is based on Japanese Patent Application No. 2021-094594 filed on June 4, 2021, and its contents are incorporated herein by reference. [Industrial applicability]

[0470] The present invention can provide an aromatic compound having excellent heat resistance, excellent solubility, excellent electron transport properties, and excellent durability of thin films to alcohol solvents. Furthermore, the present invention can provide an organic electroluminescent element having the compound, a display device and a lighting device having the organic electroluminescent element, a composition containing the compound and a solvent, a method for forming a thin film, and a method for manufacturing an organic electroluminescent element. [Explanation of Symbols]

[0471] 1 circuit board 2 Anode 3. Hole injection layer 4. Hole transport layer 5. Emitting layer 6 Electron transport layer 7 Cathode 8 Organic electroluminescent element< / g>

Claims

1. An aromatic compound represented by the following formula (1). 【Chemistry 1】 (In formula (1), G １ and G ２ This represents the following equation (3), G ３ This represents equation (4) below. 【Chemistry 2】 (In equation (3), the asterisk (*) indicates a combination with equation (1), (L2) a2 is a substructure represented by the following formula (14), Ar ２ (This is a phenyl group.) 【Transformation 3】 (In equation (14), an asterisk (*) represents a bond with an adjacent structure.) 【Chemistry 4】 (In equation (4), the asterisk (*) indicates a combination with equation (1), L ３ is a 1,3-phenylene group or a 1,4-phenylene group, a ３ It is 1.

2. The aromatic compound according to claim 1, wherein the molecular weight is 1200 or more.

3. An organic electroluminescent element having an anode and a cathode on a substrate, with an organic layer between the anode and the cathode, The aforementioned organic layer has a layer containing a material for an organic electroluminescent device. An organic electroluminescent element, wherein the material for the organic electroluminescent element is the aromatic compound described in claim 1 or 2.

4. The organic electroluminescent element according to claim 3, wherein the layer containing the organic electroluminescent element material is a light-emitting layer.

5. A display device having the organic electroluminescent element described in Claim 3.

6. A lighting device having the organic electroluminescent element described in Claim 3.

7. A composition for an organic electroluminescent element, comprising the aromatic compound and solvent described in Claim 1 or 2.

8. Furthermore, the composition for an organic electroluminescent element according to claim 7 further contains a phosphorescent material and a charge transport material.

9. The organic electroluminescent element composition according to claim 8, wherein the charge transport material is a compound represented by the following formula (240) or a compound represented by the following formula (260). 【Transformation 5】 (In formula (240), Ar ６１１ Ar ６１２ Each of these independently represents a monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms, which may have substituents. R ６１１ 、 R ６１２ each independently represents a monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a deuterium atom, a halogen atom, or a substituent, G represents a single bond or a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms, which may have substituents. n ６１１ , n ６１２ Each of these is an independent integer between 0 and 4. 【Transformation 6】 (In formula (260), Ar ２１ ~Ar ３５ Each of these independently represents a hydrogen atom, an optionally substituted phenyl group, or a monovalent group consisting of 2 to 10 optionally substituted phenyl groups, either unbranched or branched.

10. Ar in formula (240) ６１１ and Ar ６１２ The organic electroluminescent element composition according to claim 9, wherein each of them is independently a monovalent group in which a plurality of benzene rings, which may have substituents, are linked in a chain or branched manner.

11. R in formula (240) ６１１ and R ６１２ The organic electroluminescent element composition according to claim 9, wherein each of them is a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms, which may each have substituents independently.

12. n in formula (240) ６１１ and n ６１２ The organic electroluminescent element composition according to claim 9, wherein each of the elements is independently 0 or 1.

13. In the above formula (260), Ar ２１ Ar ２５ Ar ２６ Ar ３０ Ar ３１ and Ar ３５ It is a hydrogen atom, Ar ２２ ~Ar ２４ Ar ２７ ~Ar ２９ , and Ar ３２ ~Ar ３４ The organic electroluminescent element composition according to claim 9, wherein is a hydrogen atom, a phenyl group, and any of the structures selected from the following formulas (261-1) to (261-9), and these structures may have the substituents. 【Transformation 7】

14. A thin film formation method comprising the step of forming the organic electroluminescent element composition described in Claim 7 by a wet film formation method.

15. A method for manufacturing an organic electroluminescent element having an anode and a cathode on a substrate, with an organic layer between the anode and the cathode, A method for manufacturing an organic electroluminescent element, comprising the step of forming the organic layer by a wet film deposition method using the organic electroluminescent element composition described in claim 7.

16. The method for manufacturing an organic field light-emitting element according to claim 15, wherein the organic layer is a light-emitting layer.

17. A method for manufacturing an organic electroluminescent element having an anode and a cathode on a substrate, with an organic layer between the anode and the cathode, The organic layer includes a light-emitting layer and an electron transport layer. The process involves forming the light-emitting layer by a wet film deposition method using the organic electroluminescent element composition described in claim 7, A method for manufacturing an organic electroluminescent element, comprising the steps of: forming the electron transport layer by a wet film deposition method using an electron transport layer composition containing an electron transport material and a solvent, in this order.

18. The method for producing an organic field light-emitting element according to claim 17, wherein the solvent contained in the electron transport layer composition is an alcohol-based solvent.

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