Phenanthroline compound, and organic thin film and organic semiconductor element using same

Abstract

Provided are: a phenanthroline compound which, when used in an electron injection layer of an organic electroluminescent element, is capable of obtaining excellent electron injection properties and electron transport properties; and an organic thin film of the phenanthroline compound. The present invention relates to a phenanthroline compound represented by general formula (1) (In general formula (1), R1a to R1d each independently represent a hydrogen atom, an aromatic hydrocarbon group having or not having a substituent, or an aromatic heterocyclic group having or not having a substituent. And R2a and R2b each independently represent a dialkylamino group which forms or does not form a ring structure and which has or does not have a substituent. R3a and R3b independently represent a hydrogen atom, an aromatic hydrocarbon group having or not having a substituent, and an aromatic heterocyclic group having or not having a substituent;-R4 = R5-R6 (wherein R4 and R5 represent CH or N. R6 represents a hydrogen atom, an aromatic hydrocarbon group that has or does not have a substituent, or an aromatic heterocyclic group that has or does not have a substituent. ),-R7-R8 (wherein R7 represents CH2, NH, O, or S. R8 represents a hydrogen atom, an aromatic hydrocarbon group that has or does not have a substituent, or an aromatic heterocyclic group that has or does not have a substituent. ), or a fused ring structure in which R3a and R3b are bonded together. And at least one of R1a to R1d, R3a and R3b is an aromatic hydrocarbon group that has or does not have a substituent, or an aromatic heterocyclic group that has or does not have a substituent. ). # imgabs0 #

Description

Technical Field

[0001] The present invention relates to a phenanthroline compound and an organic thin film using the compound, and more particularly to an organic semiconductor element such as an organic electroluminescent element and an organic thin film solar cell using the phenanthroline compound. Background Art

[0002] Organic electroluminescent elements are thin and soft, and can be made into flexible display devices. In addition, compared with the current mainstream liquid crystal display devices and plasma display devices, display devices using organic electroluminescent elements can achieve high brightness and high-definition display. In addition, compared with liquid crystal display devices, display devices using organic electroluminescent elements have a wide viewing angle. Therefore, for display devices using organic electroluminescent elements, it is expected that the application of such as display screens for televisions and mobile phones will be expanded in the future.

[0003] In addition, the application of organic electroluminescent elements as lighting devices is also expected.

[0004] An organic electroluminescent element is formed by stacking a cathode, a light-emitting layer, and an anode. In an organic electroluminescent element, the energy difference between the work function of the anode and the highest occupied molecular orbital (HOMO) of the light-emitting layer is smaller than the energy difference between the work function of the cathode and the lowest unoccupied molecular orbital (LUMO) of the light-emitting layer. Therefore, it is more difficult to inject electrons from the cathode into the light-emitting layer than to inject holes from the anode into the light-emitting layer. Therefore, in existing organic electroluminescent elements, an electron injection layer is configured between the cathode and the light-emitting layer to promote the injection of electrons from the cathode into the light-emitting layer.

[0005] Patent Document 1 discloses an organic electroluminescent element in which an organic thin film composed of a phenanthroline derivative is formed at the interface between an electrode and an organic layer.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: International Publication No. 2021 / 045179 Summary of the invention

[0009] Problems to be solved by the invention

[0010] However, in conventional organic electroluminescent elements including an electron injection layer, the electron injection property and the electron transport property are not sufficient, and further improvement of the electron injection property and the electron transport property is required.

[0011] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a phenanthroline compound and an organic thin film thereof which can obtain excellent electron injection properties and electron transport properties when used in an electron injection layer of an organic electroluminescent element.

[0012] In addition, the present invention aims to provide a phenanthroline compound having excellent electron injection and electron transport properties, an organic semiconductor element comprising an organic thin film using the phenanthroline compound of the present invention, an organic electroluminescent element, a display device and a lighting device having the organic electroluminescent element, an organic thin film solar cell and an organic thin film transistor.

[0013] Means for solving problems

[0014] The present inventors have conducted various studies to achieve the above-mentioned object and have arrived at the present invention.

[0015] That is, the first aspect of the present invention is a phenanthroline compound represented by the following general formula (1).

[0016] [Chemistry 1]

[0017]

[0018] (In general formula (1), R 1a ~R 1d R independently represents a hydrogen atom, an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent. 2a , R 2b R independently represents a dialkylamino group which may or may not form a ring structure and may or may not have a substituent. 3a , R 3b independently represent a hydrogen atom, an aromatic hydrocarbon group which may be substituted, an aromatic heterocyclic group which may be substituted, -R 4 =R 5 -R 6 (R 4 , R 5 Represents CH or N. R 6 represents a hydrogen atom, an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent. ), -R 7 -R 8 (R 7 Represents CH2, NH, O, S. R 8 represents a hydrogen atom, an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent. ), or R 3a , R 3b Bonded to form a condensed ring structure. 1a ~R 1d , R 3a , R 3b At least one of them is an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent.

[0019] A second aspect of the present invention is an organic thin film comprising a phenanthroline compound represented by the above general formula (1).

[0020] A third aspect of the present invention is an organic semiconductor device material comprising a phenanthroline compound represented by the above general formula (1).

[0021] A fourth aspect of the present invention is the organic semiconductor device material according to the third aspect of the present invention, wherein the organic semiconductor device is any one of an organic electroluminescent device, an organic transistor, a photoelectric conversion device, and an organic solar cell.

[0022] A fifth aspect of the present invention is an organic semiconductor device comprising a phenanthroline compound represented by the above general formula (1).

[0023] A sixth aspect of the present invention is the organic semiconductor element according to the fifth aspect of the present invention, wherein the organic semiconductor element is any one of an organic electroluminescent element, an organic transistor, a photoelectric conversion element, and an organic solar cell.

[0024] A seventh aspect of the present invention is an image display device or a lighting fixture including the organic semiconductor element according to the fifth or sixth aspect of the present invention.

[0025] Effects of the Invention

[0026] The phenanthroline compound of the present invention is a material having excellent electron injection and electron transport properties and excellent heat resistance, and therefore has excellent durability when used as an organic electroluminescent element or an organic thin-film solar cell, and can be preferably used as an organic semiconductor element material. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic cross-sectional view for explaining an example of the organic EL element of the present invention.

[0028] Figure 2 This is a schematic cross-sectional view for explaining an example of the organic EL element of the present invention. DETAILED DESCRIPTION

[0029] The present invention is described in detail below.

[0030] In addition, the embodiment in which two or more of the preferred embodiments of the present invention described below are combined is also a preferred embodiment of the present invention.

[0031] [Phenanthroline compound of the present invention]

[0032] The phenanthroline compound of the present invention is a phenanthroline compound represented by the following general formula (1).

[0033] [Chemistry 2]

[0034]

[0035] (In general formula (1), R 1a ~R 1d R independently represents a hydrogen atom, an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent. 2a , R 2b R independently represents a dialkylamino group which may or may not form a ring structure and may or may not have a substituent. 3a , R 3b independently represent a hydrogen atom, an aromatic hydrocarbon group which may be substituted, an aromatic heterocyclic group which may be substituted, -R 4 =R 5 -R 6 (R 4 , R 5 Represents CH or N. R 6 represents a hydrogen atom, an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent. ), -R 7 -R 8 (R 7 Represents CH2, NH, O, S. R 8 represents a hydrogen atom, an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent. ), or R 3a , R 3b Bonded to form a condensed ring structure. 1a ~R 1d , R 3a , R 3b At least one of them is an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent.

[0036] As the above R 1a ~R 1d , R 3a , R 3b , R 6 , R 8 The aromatic hydrocarbon group includes compounds consisting of only one aromatic ring such as benzene; compounds consisting of two or more aromatic rings directly bonded to each other through one carbon atom such as biphenyl and diphenylbenzene; condensed ring aromatic hydrocarbon compounds such as naphthalene, anthracene, phenanthrene, pyrene, fluorene; aromatic hydrocarbon groups having 6 to 30 carbon atoms, such as groups obtained by removing one hydrogen atom from any aromatic ring. Among these, compounds consisting of two or more aromatic rings directly bonded to each other through one carbon atom and condensed ring aromatic hydrocarbon compounds are preferably composed of 2 to 5 aromatic rings. More preferably, they are composed of 2 to 3 aromatic rings.

[0037] As the above R1a ~R 1d , R 3a , R 3b , R 6 , R 8 The aromatic heterocyclic group includes compounds consisting of only one aromatic heterocyclic ring such as thiophene, furan, pyrrole, oxazole, oxadiazole, thiazole, thiadiazole, imidazole, pyridine, pyrimidine, pyrazine, triazine, etc.; compounds formed by multiple direct bonds between these compounds consisting of only one aromatic heterocyclic ring through one carbon atom (such as bipyridine); compounds formed by multiple direct bonds between these compounds consisting of only one aromatic heterocyclic ring and compounds consisting of only one aromatic ring such as benzene through one carbon atom (such as phenylpyridine); condensed ring heteroaromatic hydrocarbon compounds such as quinoline, quinoxaline, benzothiophene, benzothiazole, benzimidazole, benzoxazole, indole, carbazole, dibenzofuran, dibenzothiophene, acridine, phenanthroline, etc.; aromatic heterocyclic groups having 3 to 30 carbon atoms, such as groups obtained by removing one hydrogen atom from any aromatic heterocyclic ring in.

[0038] Among these, compounds consisting of only one aromatic heterocyclic ring and multiple direct bonds to each other through one carbon atom, compounds consisting of only one aromatic heterocyclic ring and compounds consisting of only one aromatic ring such as benzene and multiple direct bonds to each other through one carbon atom, and condensed heteroaromatic hydrocarbon compounds preferably consist of 2 to 5 aromatic rings, and more preferably consist of 2 to 3 aromatic rings.

[0039] The above R 1a ~R 1d , R 3a , R 3b , R 6 , R 8 Aromatic hydrocarbon groups, aromatic heterocyclic groups, R 2The dialkylamino group may have one or two or more monovalent substituents. Examples of the monovalent substituent include hydroxyl groups; halogen atoms such as fluorine atoms; halogenated alkyl groups such as fluoromethyl, difluoromethyl and trifluoromethyl; linear or branched alkyl groups having 1 to 20 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl and tert-butyl; cyclic alkyl groups having 5 to 7 carbon atoms such as cyclopentyl, cyclohexyl and cycloheptyl; linear or branched alkoxy groups having 1 to 20 carbon atoms such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, tert-butoxy, pentyloxy, hexyloxy, heptyloxy and octyloxy; nitro; cyano; alkylamino groups having an alkyl group having 1 to 10 carbon atoms such as methylamino, ethylamino, dimethylamino and diethylamino; cyclic amino groups such as pyrrolidinyl, piperidinyl and morpholinyl; diarylamino groups such as diphenylamino and carbazolyl; acyl groups such as acetyl, propionyl and butyryl; and styryl groups having 2 to 3 carbon atoms. 0 alkenyl; aryl having 5 to 20 carbon atoms which may be substituted with halogen atoms such as fluorine atoms or alkyl, alkoxy, amino, etc. having 1 to 20 carbon atoms (specific examples of aryl groups are the same as the above-mentioned aromatic hydrocarbon groups); heterocyclic groups having 4 to 20 carbon atoms and containing one or more of nitrogen atoms, sulfur atoms, and oxygen atoms which may be substituted with halogen atoms such as fluorine atoms or alkyl, alkoxy, amino, etc. having 1 to 20 carbon atoms (the heterocyclic group may be composed of only one ring, or a compound composed of only one aromatic heterocyclic ring directly bonded to each other through multiple carbon atoms, or a compound composed of only one aromatic heterocyclic ring and a compound composed of only one aromatic ring directly bonded to each other through multiple carbon atoms, or a condensed heterocyclic group. Specific examples of heterocyclic groups include the specific examples of aromatic heterocyclic groups described above.); ester groups, thioether groups, etc. In addition, these groups may be substituted with halogen atoms, heteroelements, alkyl groups, aromatic rings, etc.

[0040] As the above R 2a , R 2b The dialkylamino group preferably has an alkyl group having 1 to 20 carbon atoms, and more preferably has an alkyl group having 1 to 10 carbon atoms. In addition, the two alkyl groups in the dialkylamino group may have the same or different carbon atoms. In addition, a cyclic amino group in which two alkyl groups or alkyl groups having a substituent are linked is also preferred.

[0041] Specific examples of the dialkylamino group include dimethylamino, diethylamino, dipropylamino, methylethylamino, dibutylamino, dipentylamino, dihexylamino, dioctylamino, di(2-ethylhexyl)amino, didecylamino, didodecylamino, dioctadecylamino, pyrrolidinyl, piperidinyl, morpholinyl, tetrahydroisoquinolinyl, and isoindolyl.

[0042] As the above R 3a , R 3bThe bonded aromatic rings include aromatic hydrocarbon rings such as benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, pyrene ring, etc.; nitrogen-containing aromatic rings such as pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, quinoline ring, isoquinoline ring, quinazoline ring, quinoxaline ring, acridine ring, pyrrole ring, imidazole ring, indole ring, benzimidazole ring, carbazole ring, etc.; aromatic rings having 3 to 30 carbon atoms such as oxygen-containing aromatic rings such as furan ring and benzofuran ring, sulfur-containing aromatic rings such as thiophene ring and benzothiophene ring.

[0043] The above R 3a , R 3b The aromatic ring formed by the bonding may have one or two or more monovalent substituents. Examples of the monovalent substituents include the same substituents as those for the aromatic hydrocarbon group and the aromatic heterocyclic group.

[0044] In the compound represented by the above general formula (1), R 1a ~R 1d , R 3a , R 3b At least one of them is an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent. 1a ~R 1d , R 3a , R 3b At least one of these six groups is an aromatic hydrocarbon group which may be substituted or an aromatic heterocyclic group which may be substituted, and the number of aromatic hydrocarbon groups which may be substituted or an aromatic heterocyclic group which may be substituted is preferably two or more of these six groups. 3a , R 3b In the case of a condensed ring structure formed by bonding, it is counted as one aromatic hydrocarbon group or aromatic heterocyclic group.

[0045] In the compound represented by the above general formula (1), R 1a ~R 1d , R 3a , R 3b When the two groups in are an aromatic hydrocarbon group which may be substituted or an aromatic heterocyclic group which may be substituted, the two groups are preferably R 1a and R 1c These two groups, R 1b ~R 1d 2 groups in R 3a and R 3b Any of these two groups.

[0046] In addition, in R 1a ~R 1d , R 3a , R 3bWhen the three groups in are an aromatic hydrocarbon group which may be substituted or an aromatic heterocyclic group which may be substituted, it is preferred to form R 3a , R 3b The fused ring structure formed by bonding, and then R 1a and R 1c These two groups or R 1b ~R 1d The two groups in are an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent.

[0047] Specific examples of the compound represented by the general formula (1) include compounds represented by the following general formulas (1-1) to (1-16).

[0048] [Chemistry 3-1]

[0049]

[0050] [Chemistry 3-2]

[0051]

[0052] [Organic thin film of the present invention]

[0053] The organic film of the present invention comprises a phenanthroline compound represented by the general formula (1). The compound of the general formula (1) contained in the organic film has a phenanthroline structure, and thus functions as an n-type dopant that provides electrons to a material that transmits electrons. In addition, a coordination bond is formed with the metal of the cathode, so that the work function of the cathode changes. Therefore, the organic film of the present invention has good electron injection and transmission properties.

[0054] The organic film of the present invention may further include a material that transports electrons as a second material constituting the material, and the second material is preferably an organic material. More preferably, an organic material having a lowest unoccupied molecular orbital (LUMO) energy level of 2.0 eV to a maximum of 4.0 eV, and more preferably an n-type organic semiconductor material having a LUMO energy level of 2.5 eV to 3.5 eV. For example, as a material for the electron transport layer of an organic EL element, any of the following conventionally known materials can be used, and among these, materials that satisfy the above-mentioned LUMO energy level conditions are preferred.

[0055] As the second material, specifically, there can be mentioned phosphine oxide derivatives such as phenyldipyrenephosphine oxide (POPy2), tris-1,3,5-(3'-(pyridin-3"-yl)phenyl)benzene (TmPhPyB), 1,3,5-tris(6-(3-(pyridin-3-yl)phenyl)pyridin-2-yl)benzene, pyridine derivatives such as 8,9-diphenyl-7,10-(3-(pyridin-3-yl))fluoranthene, quinoline derivatives such as (2-(3-(9-carbazolyl)phenyl)quinoline (mCQ)), 2-phenyl-4,6-bis(3,5-bipyridylphenyl)pyrimidine (BPyPPM), 2-methyl-4,6-bis(3,5-bipyridylphenyl)pyrimidine, 9-(4-(4,6- Pyrimidine derivatives such as diphenylpyrimidin-2-yl)phenyl)-9H-carbazole, pyrazine derivatives, bathophenanthroline (BPhen), phenanthroline derivatives such as 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 2,4-bis(4-biphenyl)-6-(4'-(2-pyridyl)-4-biphenyl)-[1,3,5]triazine (MPT), tris-1,3,5-(3'-(pyridin-3″-yl)phenyl)triazine (TmPhPyTz), tris-1,3,5-([1,1′-biphenyl]-3-yl)triazine, 2-(3-(4,6-di(pyridin-3-yl)-1,3,5-triazine-2-yl)phenyl)-1-phenyl-1H-benzo[d ] imidazole, 9-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-9H-3,9'-bicarbazole, 9-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-9H-carbazole, 11-(4,6-diphenyl-1,3,5-triazin-2-yl)-12-phenyl-11,12-dihydroindole[2,3-a]carbazole, 12-(2-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-12H-benzofuro[2,3,a]-carbazole, triazine derivatives such as 9-((4-(4,6-bipyridin-3-yl)-1,3,5-triazin-2-yl)phenyl)-9H-carbazole, 3-phenyl-4 triazole derivatives such as -(1'-naphthyl)-5-phenyl-1,2,4-triazole (TAZ), oxazole derivatives, oxadiazole derivatives such as 2-(4-biphenyl)-5-(4-tert-butylphenyl-1,3,4-oxadiazole) (PBD), imidazole derivatives such as 2,2',2"-(1,3,5-benzenetriyl)-tri(1-phenyl-1-H-benzimidazole) (TPBI), aromatic ring carboxylic acid anhydrides such as naphthalene-1,4,5,8-tetracarboxylic dianhydride and 3,4,9,10-perylenetetracarboxylic dianhydride, aromatic ring imide compounds such as N,N'-dimethyl-3,4,9,10-perylenetetracarboxylic acid diimide, isoindigo derivatives, 2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-diketone derivatives (diketopyrrolopyrroles), compounds having a carbonyl group such as trimerized indanone, 1,2,5-thiadiazole derivatives such as naphtho[1,2-c:5,6-c']bis[1,2,5]thiadiazole and benzo[c][1,2,5]thiadiazole, compounds having a heterocyclic ring containing a carbonyl group such as the compound represented by the formula (30) described later, various metal complexes represented by bis[2-(2-hydroxyphenyl)benzothiazole]zinc (Zn(BTZ)2) and tris(8-hydroxyquinoline)aluminum (Alq3), 2,5-bis(6'-(2',2"-bipyridyl))- Organosilane derivatives represented by silole derivatives such as 1,1-dimethyl-3,4-diphenylsilole (PyPySPyPy), tris(2,4,6-trimethyl-3-(pyridin-3-yl)phenyl)borane (3TPYMB), boron-containing compounds described in Japanese Patent Publication No. 2013-239691, Japanese Patent Publication No. 2016-199507, Japanese Patent Publication No. 2016-199508, and International Publication No. 2014 / 133141, etc., can be used. One or more of them can be used. In addition, the material of the light-emitting layer described later can also be used as the second material. ,

[0056] Among these second materials, it is more preferable to use a phosphine oxide derivative such as POPy2, a metal complex such as Alq3, a pyridine derivative such as TmPhPyB, or a triazine derivative such as TmPhPyTz.

[0057] In addition, the second material may include a compound having no structure coordinated with an alkali metal in the molecule. As the second material, a compound having an aromatic heterocycle without a carbon-nitrogen double bond in the structure and a compound having no π-electron-deficient aromatic heterocycle in the molecule are preferred. In addition, as the above-mentioned second material, a compound represented by the following general formula (2) is also preferred.

[0058] [Chemistry 4]

[0059]

[0060] (In the general formula (2), Y represents any one of an aromatic hydrocarbon group with or without a substituent, a π-electron-rich aromatic heterocyclic group, and a π-conjugated cyclic structure group containing silicon and / or boron as constituent elements. W represents a connecting group or a direct bond. Z represents an aromatic group that does not contain a carbon-nitrogen double bond in its structure. r is an integer of 1 to 6. s is an integer of 1 to 6.)

[0061] In the general formula (2), Y represents any one of an aromatic hydrocarbon group which may have a substituent, a π-electron-rich aromatic heterocyclic group, and a π-conjugated cyclic structural group containing silicon and / or boron as constituent elements.

[0062] Examples of the aromatic hydrocarbon group include a benzene ring, a naphthalene ring, an anthracene ring, a biphenyl ring, a triphenylene ring, a fluoranthene ring, a fluorene ring, Cyclopentadiene, dibenzo An aromatic hydrocarbon group having 6 to 30 carbon atoms, such as a ring.

[0063] Examples of the π-electron-rich aromatic heterocyclic group include π-electron-rich aromatic heterocyclic groups having 3 to 20 carbon atoms, such as a thiophene ring, a furan ring, a pyrrole ring, a dibenzothiophene ring, a dibenzofuran ring, and a carbazole ring.

[0064] Examples of the π-conjugated cyclic structural group containing silicon and / or boron as constituent elements include a silole ring, a dibenzo[g,p] A group having 3 to 30 carbon atoms, such as a ring structure in which a part of the ring is substituted with nitrogen-boron, and a ring structure in which a part of the spiro-bifluorene ring is substituted with nitrogen-boron.

[0065] The aromatic hydrocarbon group, the π-electron-rich aromatic heterocyclic group, and the π-conjugated cyclic structure group containing silicon and / or boron as constituent elements may have a substituent, and examples of the substituent include the same substituents as R in the general formula (1). 1 ~R 3 , R 6 , R 8 The same group as the monovalent substituent of .

[0066] In the general formula (2), W represents a linking group or a direct bond. When W is a linking group, W is a linking group having a valence of (r+1).

[0067] Here, examples of the linking group include an arylene group, a heteroarylene group, a vinylene group, an ethynylene group, a nitrogen atom, an oxygen atom, a sulfur atom, a silicon atom, a boron atom, and the like. These linking groups may have a substituent, and examples of the substituent include the same substituent as R in the general formula (1). 1 ~R 3 , R 6 , R 8 The same group as the monovalent substituent of .

[0068] In the general formula (2), Z represents an aryl group having no carbon-nitrogen double bond in its structure. Here, examples of the aryl group having no carbon-nitrogen double bond in its structure include groups having 6 to 30 carbon atoms, such as phenyl, tolyl, naphthyl, benzo[9,10]phenanthryl, fluoranthenyl, dibenzothienyl, dibenzofuranyl, and carbazolyl. The above aryl group may have a substituent as long as it does not have a carbon-nitrogen double bond in its structure. Examples of the substituent include groups having the same carbon atoms as R in the general formula (1). 1 ~R 3 , R 6 , R 8The same group as the monovalent substituent of .

[0069] In the general formula (2), r is an integer of 1 to 6, and s is an integer of 1 to 6. Here, when r is an integer of 2 to 6, a plurality of Zs present may be the same or different. In addition, when s is an integer of 2 to 6, a plurality of Ws present may be the same or different, and a plurality of Zs present may be the same or different.

[0070] In the organic film of the present invention, the exchange of electrons between the cathode and the organic layer can be smoothly carried out by the coordination reaction between the phenanthroline compound represented by the general formula (1) and the metal. Therefore, in the present invention, the second material need not be a material that has been used so far in an organic electroluminescent element or an organic thin film solar cell between a light-emitting layer or a photoelectric conversion layer and a cathode and can inject electrons by interaction with an alkali metal.

[0071] The ratio of the phenanthroline compound to the second material contained in the organic thin film of the present invention is not particularly limited, and can be appropriately determined according to the types of the phenanthroline compound and the second material used.

[0072] In the present invention, the organic thin film containing the second material may be a single film containing the phenanthroline compound and the second material, or may be a laminated film of a film containing at least the phenanthroline compound and a film containing at least the second material.

[0073] In the case of a laminated film, it may be a laminated film of a film containing only a phenanthroline compound and a film containing only a second material, or a laminated film of a film containing a phenanthroline compound and a second material and a film containing only one of the phenanthroline compound and the second material.

[0074] In the case of a laminated film of a film containing a phenanthroline compound and a second material and a film containing only either the phenanthroline compound or the second material, the film containing only the phenanthroline compound and the second material may contain either the phenanthroline compound or the second material, and preferably contains the second material.

[0075] In addition, when such an organic thin film is used as a layer constituting an organic electroluminescent element, either a film containing a phenanthroline compound and a second material or a film containing only either a phenanthroline compound and the second material can be located on the cathode side, and preferably the film containing a phenanthroline compound is located on the cathode side.

[0076] When the organic thin film in the present invention is a laminated film of a film containing a phenanthroline compound and a second material and a film containing only the first material, both laminated films contain a phenanthroline compound, and the phenanthroline compounds contained in the two films may be the same or different.

[0077] Similarly, when the organic thin film in the present invention is a laminated film of a film containing a phenanthroline compound and a second material and a film containing only the second material, both of the laminated films contain the second material, and the second materials contained in the two films may be the same or different.

[0078] [Method for producing organic thin film of the present invention]

[0079] Next, the method for producing an organic thin film of the present invention will be described with reference to examples.

[0080] The organic film of the present invention comprises a phenanthroline compound composed of an electron-donating compound having a structure represented by the general formula (1). The organic film of the present invention can be formed not only by coating but also by vapor deposition. Therefore, there are few process constraints when manufacturing an organic electroluminescent element comprising the organic film of the present invention, and it is easy to use as a material for a layer constituting an organic electroluminescent element.

[0081] In the case of manufacturing an organic thin film having a second material by vapor deposition, the same method as that used to manufacture other layers constituting an organic electroluminescent element by vapor deposition can be used. For example, the phenanthroline compound and the second material can be vapor deposited simultaneously or sequentially. In the case of sequential vapor deposition, either the phenanthroline compound or the second material can be vapor deposited first. In addition, either one can be vapor deposited first and then both can be co-deposited, or both can be co-deposited and then either one can be vapor deposited. Such a method for manufacturing an organic thin film, which includes the steps of simultaneously vapor depositing a phenanthroline compound, which is a compound having a structure represented by the above-mentioned general formula (1), and a second material, which is a compound that does not have a structure coordinated with an alkali metal in the molecule, on the formed surface of the organic thin film, is one of the preferred embodiments of the method for manufacturing an organic thin film of the present invention.

[0082] In addition, the following method for manufacturing an organic thin film is also one of the preferred embodiments of the method for manufacturing an organic thin film of the present invention: a method for manufacturing an organic thin film comprising the step of first vapor-depositing a phenanthroline compound or a second material on the surface to be formed of the organic thin film, and then vapor-depositing another material or two materials; or a method for manufacturing an organic thin film comprising the step of simultaneously vapor-depositing a phenanthroline compound and a second material on the surface to be formed of the organic thin film, and then vapor-depositing a phenanthroline compound or a second material on the surface to be formed of the organic thin film.

[0083] In addition, the organic film of the present invention can also be manufactured by coating, in this case, it is also possible to manufacture the organic film by making the coating composition comprising the phenanthroline compound and the coating composition being coated. In addition, when the organic film has the second material, it is possible to make the coating composition comprising the phenanthroline compound and the second material and the coating composition being coated, it is also possible to make the coating composition comprising the phenanthroline compound and the coating composition comprising the second material respectively and coat them successively. In the case of coating successively, it is possible to first coat the coating composition comprising the phenanthroline compound, any one of the coating composition comprising the second material. In addition, it is possible to coat the coating composition comprising these two materials after coating the coating composition comprising only any one material, it is also possible to coat the coating composition comprising these two materials after coating the coating composition comprising only any one material.

[0084] Such a method for producing an organic film, which includes the step of coating a coating composition comprising a phenanthroline compound which is a compound having a structure represented by the above-mentioned general formula (1) and a second material which is a compound which does not have a structure coordinated with an alkali metal in its molecule, on the surface to be formed of the organic film, is one of the preferred embodiments of the method for producing an organic film of the present invention.

[0085] In addition, the following method for manufacturing an organic thin film is also one of the preferred embodiments of the method for manufacturing an organic thin film of the present invention: a method for manufacturing an organic thin film comprising the step of first coating a coating composition containing only a phenanthroline compound or a coating composition containing only a second material on the formed surface of the organic thin film, and the step of coating a coating composition containing another material or two materials on the coating film formed by the step; or a method for manufacturing an organic thin film comprising the step of coating a coating composition containing two materials, a phenanthroline compound and a second material, and the step of coating a coating composition containing only a phenanthroline compound or either the second material on the coating film formed by the step.

[0086] Hereinafter, a method for producing an organic thin film by preparing a coating composition containing a phenanthroline compound having a structure represented by general formula (1) and a second material which is a compound having no structure coordinated with an alkali metal in its molecule and applying the coating composition will be described.

[0087] The coating composition can be obtained, for example, by supplying predetermined amounts of the phenanthroline compound and the second material to a solvent placed in a container, respectively, and stirring to dissolve the components.

[0088] As the solvent for dissolving the phenanthroline compound and the second material, for example, an inorganic solvent, an organic solvent, or a mixed solvent containing these solvents can be used.

[0089] Examples of the inorganic solvent include nitric acid, sulfuric acid, ammonia, hydrogen peroxide, water, and carbon disulfide.

[0090] Examples of the organic solvent include methyl ethyl ketone (MEK), acetone, diethyl ketone, methyl isobutyl ketone (MIBK), methyl isopropyl ketone (MIPK), diisobutyl ketone, 3,5,5-trimethylcyclohexanone, diacetone alcohol, cyclopentanone, and cyclohexanone; alcohol solvents such as methanol, ethanol, isopropyl alcohol, ethylene glycol, diethylene glycol (DEG), and glycerol; ether solvents such as diethyl ether, diisopropyl ether, 1,2-dimethoxyethane (DME), 1,4-dioxane, tetrahydrofuran (THF), tetrahydropyran (THP), anisole, diethylene glycol dimethyl ether (diglyme), and diethylene glycol ethyl ether (carbitol); cellosolve solvents such as methyl cellosolve, ethyl cellosolve, and phenyl cellosolve; aliphatic hydrocarbon solvents such as hexane, pentane, heptane, and cyclohexane; aromatic hydrocarbon solvents such as toluene, xylene, and benzene; Various organic solvents such as aromatic heterocyclic compound solvents such as pyridine, pyrazine, furan, pyrrole, thiophene, and methylpyrrolidone, amide solvents such as N,N-dimethylformamide (DMF) and N,N-dimethylacetamide (DMA), halogenated compound solvents such as chlorobenzene, dichloromethane, chloroform, 1,2-dichloroethane, and carbon tetrachloride, ester solvents such as ethyl acetate, methyl acetate, ethyl formate, and ethylene carbonate, sulfur compound solvents such as dimethyl sulfoxide (DMSO) and sulfolane, nitrile solvents such as acetonitrile, propionitrile, and acrylonitrile, and organic acid solvents such as formic acid, acetic acid, trichloroacetic acid, and trifluoroacetic acid. Among them, ketone solvents such as methyl ethyl ketone (MEK), acetone, diethyl ketone, methyl isobutyl ketone (MIBK), methyl isopropyl ketone (MIPK), diisobutyl ketone, 3,5,5-trimethylcyclohexanone, diacetone alcohol, and cyclopentanone are preferred.

[0091] As a method for applying a coating composition containing a phenanthroline compound and a second material, various coating methods can be used, for example, spin coating, cast coating, micro-gravure coating, gravure coating, rod coating, roller coating, wire rod coating, dip coating, spray coating, screen printing, flexographic printing, offset printing, inkjet printing and the like.

[0092] After the coating composition is applied in this manner, an annealing treatment is preferably performed. The annealing treatment is preferably performed at 70 to 200° C. in a nitrogen atmosphere or in the air for 0.1 to 5 hours. By performing such an annealing treatment, the solvent can be vaporized to form an organic thin film.

[0093] [Organic electroluminescent element of the present invention]

[0094] The present invention also relates to an organic electroluminescent element (organic EL element), which has a light-emitting layer between a cathode and an anode, and further comprises any one of a layer of an organic thin film of the present invention, a layer of a laminated film of the organic thin film layer and a metal oxide layer, or a layer comprising a material for an organic electroluminescent element of the present invention.

[0095] The above-mentioned organic thin film layer, the layer of the laminated film of the organic thin film layer and the metal oxide layer, and the layer containing the material for the organic electroluminescent element of the present invention can be located between the cathode and the light-emitting layer, or between the anode and the light-emitting layer in the organic electroluminescent element of the present invention, but is preferably located between the cathode and the light-emitting layer.

[0096] The layer containing the material for an organic electroluminescent device of the present invention may contain the phenanthroline compound represented by the general formula (1) and may contain the second material and other components. However, it is preferably a layer consisting only of the phenanthroline compound represented by the general formula (1).

[0097] Next, the organic electroluminescent element of the present invention will be described in detail with reference to examples.

[0098] Figure 1 This is a schematic cross-sectional view for explaining an example of the organic electroluminescent element of the present invention. Figure 1 The organic electroluminescent element 1 of the present embodiment shown includes a light-emitting layer 6 between an anode 3 and a cathode 9 . Figure 1 In the organic electroluminescent element 1 shown, an electron injection layer 8 composed of the organic thin film of the present invention or the material for an organic electroluminescent element of the present invention is provided between a cathode 9 and a light-emitting layer 6 .

[0099] The organic electroluminescent element 1 of this embodiment has a stacked structure in which an anode 3 , a hole injection layer 4 , a hole transport layer 5 , a light emitting layer 6 , an electron transport layer 7 , an electron injection layer 8 , and a cathode 9 are sequentially formed on a substrate 2 .

[0100] Figure 1 The organic electroluminescent element 1 shown is a representative organic electroluminescent element having an anode 3 on the substrate 2 side. Figure 2 As shown, an inverted structure organic electroluminescent element 1 in which a cathode 9 is disposed between the substrate 2 and the light-emitting layer 6 is also one of the preferred embodiments of the organic electroluminescent element of the present invention.

[0101] Furthermore, one of the preferred embodiments of the organic electroluminescent element of the present invention is a mode in which an inorganic oxide layer 10 is provided between the cathode 9 and the electron injection layer 8 composed of the organic thin film of the present invention or the material for an organic electroluminescent element of the present invention.

[0102] Figure 1 and Figure 2The organic electroluminescent element 1 shown may be a top emission type element in which light is extracted on the side opposite to the substrate 2 , or may be a bottom emission type element in which light is extracted on the substrate 2 side.

[0103] <Substrate>

[0104] Examples of the material of the substrate 2 include resin materials and glass materials.

[0105] As the resin material used for the substrate 2, polyethylene terephthalate, polyethylene naphthalate, polypropylene, cycloolefin polymer, polyamide, polyether sulfone, polymethyl methacrylate, polycarbonate, polyarylate, etc. can be cited. When a resin material is used as the material of the substrate 2, an organic electroluminescent element 1 having excellent flexibility can be obtained, so it is preferred.

[0106] Examples of the glass material used for the substrate 2 include quartz glass and soda glass.

[0107] When the organic electroluminescent element 1 is a bottom emission type element, a transparent substrate is used as a material of the substrate 2 .

[0108] When the organic electroluminescent element 1 is a top emission type element, not only a transparent substrate but also an opaque substrate can be used as the material of the substrate 2. Examples of the opaque substrate include a substrate made of a ceramic material such as alumina, a substrate having an oxide film (insulating film) formed on the surface of a metal plate such as stainless steel, and a substrate made of a resin material.

[0109] The average thickness of the substrate 2 can be determined depending on the material of the substrate 2 and the like, but is preferably 0.02 to 30 mm, more preferably 0.05 to 10 mm.

[0110] The average thickness of the substrate 2 can be measured using a digital multimeter or a vernier caliper.

[0111] <Anode>

[0112] Figure 1 The anode 3 shown is formed on the substrate 2 in a direct contact manner, but Figure 2 In the case of an organic electroluminescent element having such an inverted structure, it is not necessary to form it on the substrate 2 in a manner not in direct contact with it.

[0113] As the material of the anode 3, there can be cited oxide conductive materials such as ITO (indium tin oxide), IZO (indium zinc oxide), FTO (fluorine-doped tin oxide), In3O3, SnO2, SnO2 containing Sb, and ZnO containing Al. Among them, as the material of the anode 3, ITO, IZO, and FTO are preferably used.

[0114] The average thickness of the anode 3 is not particularly limited, but is preferably 10 to 500 nm, more preferably 100 to 200 nm.

[0115] The average thickness of the anode 3 can be measured using a probe profilometer or a spectroscopic ellipsometer.

[0116] <Hole Injection Layer>

[0117] The hole injection layer 4 may be a layer composed of an inorganic material or a layer composed of an organic material.

[0118] The inorganic material is not particularly limited, and for example, one or more metal oxides such as vanadium oxide (V2O5), molybdenum oxide (MoO3), and ruthenium oxide (RuO2) can be used.

[0119] As organic materials, low molecular weight materials such as dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN), 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ), poly(3,4-ethylenedioxythiophene) / polystyrene sulfonate (PEDOT:PSS), etc. can be used.

[0120] The average thickness of the hole injection layer 4 is not particularly limited, but is preferably 1 to 1000 nm, more preferably 5 to 50 nm.

[0121] The average thickness of the hole injection layer 4 can be measured using, for example, a probe profilometer or a spectroscopic ellipsometer.

[0122] <Hole Transport Layer>

[0123] As the hole transporting organic material used in the hole transporting layer 5 , various p-type high molecular weight materials (organic polymers) and various p-type low molecular weight materials can be used alone or in combination.

[0124] Specifically, as the material of the hole transport layer 5, for example, N,N'-di(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (α-NPD), N4,N4'-bis(dibenzo[b,d]thiophene-4-yl)-N4,N4'-diphenylbiphenyl-4,4'-diamine (DBTPB), polyarylamine, fluorene-arylamine copolymer, fluorene-bithiophene copolymer, poly(N-vinylcarbazole), polyvinylpyrene, polyvinylanthracene, polythiophene, polyalkylthiophene, polyhexylthiophene, poly(p-phenylenevinylene), poly(thiopheneacetylene), pyrene formaldehyde resin, ethylcarbazole formaldehyde resin or its derivatives can be cited. These materials for the hole transport layer 5 can also be used as a mixture with other compounds. As an example, as a mixture containing polythiophene used as a material for the hole transport layer 5 , poly(3,4-ethylenedioxythiophene / styrenesulfonic acid) (PEDOT / PSS) and the like can be cited.

[0125] The average thickness of the hole transport layer 5 is not particularly limited, but is preferably 10 to 150 nm, more preferably 20 to 100 nm.

[0126] The average thickness of the hole transport layer 5 can be measured using, for example, a probe profilometer or a spectroscopic ellipsometer.

[0127] <Luminous Layer>

[0128] As a material for forming the light-emitting layer 6, any material that can be generally used as a material for the light-emitting layer 6 can be used, or a mixture of these materials can be used. Specifically, for example, as the light-emitting layer 6, bis[2-(2-benzothiazolyl)phenol]zinc(II) (Zn(BTZ)2) and tris[1-phenylisoquinoline]iridium(III) (Ir(piq)3) can be included.

[0129] The material forming the light emitting layer 6 may be a low molecular compound or a high molecular compound. It should be noted that the low molecular material in the present invention refers to a material that is not a high molecular material (polymer), and does not necessarily refer to an organic compound with a low molecular weight.

[0130] Examples of the polymer material forming the light-emitting layer 6 include: polyacetylene compounds such as trans-polyacetylene, cis-polyacetylene, poly(diphenylvinylene) (PDPA), and poly(alkylphenylvinylene) (PAPA); poly(p-phenylenevinylene) (PPV), poly(2,5-dialkoxy-p-phenylenevinylene) (RO-PPV), cyano-substituted poly(p-phenylenevinylene) (CN-PPV), poly(2-dimethyloctylsilyl-p-phenylenevinylene) (DMOS-PPV), and poly(2-methoxy, 5-(2'-ethylhexyloxy)-p-phenylenevinylene) (MEH-PPV); poly(3-alkylthiophene) (PAT), and poly(oxypropylene) triol (POPT); poly(9,9-dialkylfluorene) (PDAF), poly(dioctylfluorene-alt-benzothiadiazole) (F8BT), α,ω- -polyfluorene compounds such as bis[N,N'-di(methylphenyl)aminophenyl]-poly[9,9-bis(2-ethylhexyl)fluorene-2,7-diyl](PF2 / 6am4), poly(9,9-dioctyl-2,7-dienylidenefluorene-alternating copolymer(anthracene-9,10-diyl); poly(p-phenylene) (PPP), poly(1,5-dialkoxyp-phenylene) (RO-PPP); poly(N-vinylcarbazole) (PVK) such as polycarbazole; poly(methylphenylsilane) (PMPS), poly(naphthylphenylsilane) (PNPS), poly(biphenylphenylphenylsilane) (PBPS); and boron compound-based polymer materials described in Japanese Patent Application Publication No. 2011-184430 and Japanese Patent Application Publication No. 2012-151148.

[0131] Examples of low molecular weight materials for forming the light emitting layer 6 include various metal complexes such as a three-coordinate iridium complex having 2,2'-bipyridine-4,4'-dicarboxylic acid as a ligand, tris(2-phenylpyridine)iridium (Ir(ppy)3), 8-hydroxyquinoline aluminum (Alq3), tris(4-methyl-8-hydroxyquinoline)aluminum(III) (Almq3), 8-hydroxyquinoline zinc (Znq2), (1,10-phenanthroline)-tris(4,4,4-trifluoro-1-(2-thienyl)butane-1,3-dione)europium(III) (Eu(TTA)3(phen)), and 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphine platinum(II); benzene compounds such as distyrylbenzene (DSB) and diaminodistyrylbenzene (DADSB); naphthalene compounds such as naphthalene and Nile red; and phenanthrene compounds such as phenanthrene. 6-Nitro Such perylene compounds such as perylene and N,N'-bis(2,5-di-tert-butylphenyl)-3,4,9,10-perylenedicarboxylic acid imide (BPPC); coronene compounds such as coronene; anthracene compounds such as anthracene and distyrylanthracene; pyrene compounds such as pyrene; pyran compounds such as 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminophenyl)-4H-pyran (DCM); acridine compounds such as acridine; stilbene compounds such as stilbene; thiophene compounds such as 2,5-dibenzoxazolothiophene; benzoxazole compounds such as benzoxazole; benzimidazole compounds such as benzimidazole; benzothiazole compounds such as 2,2'-(p-phenylenedivinylene)bisbenzothiazole; distyryl (1,4-diphenyl-1,3-butadiene), tetraphenylbutadiene Such butadiene compounds; naphthylimide compounds such as naphthalimide; coumarin compounds such as coumarin; perinone compounds such as perinone; oxadiazole compounds such as oxadiazole; aldazine compounds; cyclopentadiene compounds such as 1,2,3,4,5-pentaphenyl-1,3-cyclopentadiene (PPCP); quinacridone compounds such as quinacridone and quinacridone red; pyridine compounds such as pyrrolopyridine and thiadiazolopyridine; spiro compounds such as 2,2',7,7'-tetraphenyl-9,9'-spirobifluorene; metal or metal-free phthalocyanine compounds such as phthalocyanine (H2Pc) and copper phthalocyanine; and boron compound materials described in Japanese Patent Publication No. 2009-155325, Japanese Patent Publication No. 2011-184430 and Japanese Patent Publication No. 2012-151149, etc.

[0132] The average thickness of the light-emitting layer 6 is not particularly limited, but is preferably 10 to 150 nm, more preferably 20 to 100 nm.

[0133] The average thickness of the light-emitting layer 6 can be measured using a probe profilometer, or can be measured using a crystal oscillator film thickness meter when the light-emitting layer 6 is formed.

[0134] <Electron Transport Layer>

[0135] As the electron transport layer 7 , the material used as the second material in the electron injection layer 8 and conventionally used as a material for the electron transport layer can be used.

[0136] On the other hand, although the number of materials required for the production of organic electroluminescent elements will increase, a compound capable of electron injection by an alkali metal, which has been commonly used as a material for the electron transport layer, can be used as a hole blocking layer between the light-emitting layer 6 and the electron transport layer 7, for example.

[0137] The average thickness of the electron transport layer 7 is not particularly limited, but is preferably 10 to 150 nm, more preferably 20 to 100 nm.

[0138] The average thickness of the electron transport layer 7 can be measured using a probe profilometer or a spectroscopic ellipsometer.

[0139] On the other hand, as described later, when an organic thin film formed by mixing the phenanthroline compound of the present invention and the second material is used as the electron injection layer 8 and the electron transport layer 7, the electron transport layer may not be provided.

[0140] <Electron Injection Layer>

[0141] The electron injection layer 8 improves the electron injection rate and electron transport properties from the cathode 9 to the light emitting layer 6. The electron injection layer 8 is composed of an organic thin film containing the phenanthroline compound of the present invention.

[0142] The average thickness of the electron injection layer 8 is preferably 0.5 to 100 nm, more preferably 1 to 50 nm.

[0143] The electron injection layer 8 composed of an organic thin film containing the phenanthroline compound of the present invention is obtained by using a coating composition containing the phenanthroline compound of the present invention or a vacuum evaporation method. In addition, when the average thickness of the electron injection layer 8 is 100 nm or less, the increase in the driving voltage of the organic electroluminescent element 1 caused by the provision of the electron injection layer 8 can be fully suppressed.

[0144] In addition, when the film containing the phenanthroline compound of the present invention and the second material is used as the electron injection layer 8, any of the following structures may be used.

[0145] For example, the structure may be that the mixed film of the phenanthroline compound of the present invention and the second material is used as the electron injection layer 8, and the film composed of the second material is used as the electron transport layer 7; the structure may be that the film composed of only the phenanthroline compound of the present invention is used as the electron injection layer 8, and the film composed of only the second material is used as the electron transport layer 7; the structure may be that the laminated film of the second material and the phenanthroline compound of the present invention is used as the electron injection layer 8, and the film composed of only the second material is used as the electron transport layer 7; the structure may be that there is a film composed of the second material on the cathode 9 side, and the laminated film of the mixed film of the phenanthroline compound of the present invention and the second material is used as the electron injection layer 8, and the film composed of only the second material is used as the electron transport layer 7; the mixed film of the phenanthroline compound of the present invention and the second material may be used as the electron injection layer 8 and the electron transport layer 7 as described above. It should be noted that, when two adjacent films both contain the second material, the second materials contained in the two films may be the same or different.

[0146] The average thickness of the electron injection layer 8 can be measured using, for example, a probe profilometer or a spectroscopic ellipsometer.

[0147] It is reported that in either the case of metal vapor deposition on an organic film or the case of organic film vapor deposition on a cathode, the metal diffuses a few nanometers toward the organic film side (see Lee, J. Het al, Direct evidence of Al diffusion into tris-(8-hydroquinoline)aluminum layer: medium energy ion scattering analysis. Applied Physics Letters 93, doi: 10.1063 / 1.3002290 (2008). and Fukagawa, H. et al. Long-Lived Flexible Displays Employing Efficient and Stable Inverted Organic Light-Emitting Diodes. Adv. Mater. 30, e1706768, doi: 10.1002 / adma.201706768 (2018).). Therefore, even if there is a laminated structure such as the second material on the cathode 9 side, the effect of electron injection brought about by the coordination reaction with the phenanthroline compound of the present invention can be obtained by diffusion of the metal. That is, even if the phenanthroline compound of the present invention is not directly formed on the cathode 9, the effect of the present invention can be obtained. In the case where the organic electroluminescent element includes a cathode in the laminated structure, and a layer of the organic thin film of the present invention formed under the cathode, the organic electroluminescent element can be said to be composed of a laminated film of the present invention.

[0148] Such an organic electroluminescent device including the laminated film of the present invention is also one of the present invention.

[0149] The organic electroluminescent element of the present invention may have a laminated film as the electron injection layer 8. That is, a laminated film having a film containing the phenanthroline compound of the present invention and the second material and a film containing the second material between the cathode 9 and the light-emitting layer 6 is one of the preferred embodiments of the organic electroluminescent element of the present invention.

[0150] In this case, an organic electroluminescent element having a layer containing the second material between the light-emitting layer 6 and the film containing the phenanthroline compound of the present invention and the second material, and an organic electroluminescent element having a layer containing the second material between the cathode 9 and the film containing the first material and the second material are both preferred embodiments of the organic electroluminescent element of the present invention.

[0151] <Cathode>

[0152] Examples of the material used for the cathode 9 include ITO, IZO, Au, Pt, Ag, Cu, Al, Mg, and alloys thereof. Among them, ITO, IZO, Au, Ag, and Al are preferably used as the material for the cathode 9.

[0153] The average thickness of the cathode 9 is not particularly limited, but is preferably 10 to 1000 nm, more preferably 30 to 150 nm. In addition, even when a light-impermeable material is used as the material of the cathode 9, for example, by making the average thickness about 10 to 30 nm, it can be used as a transparent cathode in a top-emitting organic electroluminescent element.

[0154] The average thickness of cathode 9 can be measured by using a crystal oscillator film thickness meter when cathode 9 is formed.

[0155] <Oxide Layer for Electron Injection>

[0156] The organic thin film of the present invention is applied to Figure 2 In the case of the inverted structure organic electroluminescent element shown, it is preferred to have an inorganic oxide layer 10 on the cathode 9. The oxide layer 10 has a function as an electron injection layer 8 and / or a function as a cathode 9. The electron injection layer 8 used between the light-emitting layer 6 and the cathode 9 can also be applied to the inverted structure organic electroluminescent element, but the oxide layer 10 is inserted between the cathode 9 and the organic layer.

[0157] The oxide layer 10 is a layer of semiconductor or insulator laminated thin films. Specifically, the oxide layer 10 may be a layer composed of a single metal oxide; a layer composed of a mixture of two or more metal oxides and a layer composed of a single metal oxide or a layer composed of both of the two; or a layer composed of a mixture of two or more metal oxides.

[0158] Examples of the metal element constituting the metal oxide forming the oxide layer 10 include magnesium, calcium, strontium, barium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, indium, gallium, iron, cobalt, nickel, copper, zinc, cadmium, aluminum, and silicon.

[0159] When the oxide layer 10 includes a layer formed by mixing two or more metal oxides, it is preferably a layer in which at least one of the metal elements constituting the metal oxides is composed of magnesium, aluminum, calcium, zirconium, hafnium, silicon, titanium, or zinc.

[0160] When the oxide layer 10 is a layer composed of a single metal oxide, it is preferably a layer composed of a metal oxide selected from the group consisting of magnesium oxide, aluminum oxide, zirconium oxide, hafnium oxide, silicon oxide, titanium oxide, and zinc oxide.

[0161] In the case where the oxide layer 10 is a layer formed by laminating a layer composed of a mixture of two or more metal oxides and a layer composed of a single metal oxide, or a layer formed by laminating two or more metal oxides, examples include a layer formed by laminating and / or mixing a combination of two metal oxides selected from titanium oxide / zinc oxide, titanium oxide / magnesium oxide, titanium oxide / zirconium oxide, titanium oxide / aluminum oxide, titanium oxide / hafnium oxide, titanium oxide / silicon oxide, zinc oxide / magnesium oxide, zinc oxide / zirconium oxide, zinc oxide / hafnium oxide, zinc oxide / silicon oxide, and calcium oxide / aluminum oxide; a layer formed by laminating and / or mixing a combination of three metal oxides selected from titanium oxide / zinc oxide / magnesium oxide, titanium oxide / zirconium oxide, titanium oxide / zinc oxide / aluminum oxide, titanium oxide / zinc oxide / hafnium oxide, titanium oxide / zinc oxide / silicon oxide, and indium oxide / gallium oxide / zinc oxide; and the like.

[0162] The oxide layer 10 may include an oxide semiconductor IGZO (indium gallium zinc oxide) and / or an electronic compound 12CaO·7Al 2 O 3 which exhibit excellent characteristics as a special composition.

[0163] The average thickness of the oxide layer 10 is not particularly limited, but is preferably 1 to 1000 nm, and more preferably 2 to 100 nm.

[0164] The average thickness of the oxide layer 10 can be measured using a probe profilometer or a spectroscopic ellipsometer.

[0165] <Seal>

[0166] Figure 1 and Figure 2 The organic electroluminescent element 1 shown can be sealed as required.

[0167] For example, Figure 1 and Figure 2 The organic electroluminescent element 1 shown can be sealed by using a sealed container (not shown) having a concave space for accommodating the organic electroluminescent element 1 and an adhesive for bonding the edge of the sealed container to the substrate 2. Alternatively, the organic electroluminescent element 1 can be sealed by accommodating the sealed container and filling it with a sealing material composed of an ultraviolet (UV) curable resin or the like.

[0168] In addition, for example, Figure 1 The organic electroluminescent element 1 shown can also be sealed using a sealing member composed of a plate member (not shown) arranged on the cathode 9 and a frame member (not shown) arranged along the edge of the plate member on the side opposite to the cathode 9, and an adhesive for bonding the plate member to the frame member and the frame member to the substrate 2.

[0169] in addition, Figure 2 The organic electroluminescent element 1 shown can also be sealed using a sealing member composed of a plate member (not shown) arranged on the anode 3 and a frame member (not shown) arranged along the edge of the plate member on the side opposite to the anode 3, and an adhesive for bonding the plate member and the frame member and the frame member and the substrate 2.

[0170] When the organic electroluminescent element 1 is sealed by using a sealed container or a sealing member, a desiccant material that absorbs moisture can be arranged in the sealed container or on the inner side of the sealing member. In addition, a material that absorbs moisture can also be used as the sealed container or the sealing member. In addition, a space can be formed in the sealed container or on the inner side of the sealing member after sealing.

[0171] As will Figure 1 and Figure 2 The material of the sealed container or sealing member used when the organic electroluminescent element 1 is sealed can be a resin material, a glass material, etc. The resin material and the glass material used in the sealed container or the sealing member can be the same as the material used in the substrate 2.

[0172] In the organic electroluminescent element 1 of the present embodiment, when the electron injection layer 8 is formed by using a film composed of the phenanthroline compound of the present invention and a second material that is a compound that does not have a structure coordinated with an alkali metal in the molecule as an organic thin film, for example, excellent durability can be obtained compared to the case where an alkali metal that is unstable in the atmosphere is used as the electron injection layer 8. Therefore, as long as the water vapor permeability of the sealed container or the sealing member is 10 -3 ~10 -4 g / m 2 / day, the degradation of the organic electroluminescent element 1 can be sufficiently suppressed. Therefore, as the material of the sealed container or the sealing member, a material with a water vapor transmission rate of more than 10 -4 g / m 2 A resin material having a thickness of about 1000 nm / day can realize an organic electroluminescent element 1 having excellent flexibility.

[0173] [Method for producing organic electroluminescent element]

[0174] Next, as an example of a method for producing an organic electroluminescent element of the present invention, Figure 1 A method for manufacturing the organic electroluminescent element 1 shown will be described.

[0175] To manufacture Figure 1 In the organic electroluminescent element 1 shown, the anode 3 is first formed on the substrate 2 .

[0176] Anode 3 can be formed by sputtering, vacuum deposition, sol-gel method, spray pyrolysis (SPD), atomic layer deposition (ALD), vapor phase film formation, liquid phase film formation, etc. Anode 3 can also be formed by bonding metal foil.

[0177] Next, the hole injection layer 4 is formed on the anode 3 .

[0178] The hole injection layer 4 can be formed by the above-mentioned method for producing an organic thin film.

[0179] Next, the hole transport layer 5 , the light emitting layer 6 , the electron transport layer 7 and the electron injection layer 8 are sequentially formed on the hole injection layer 4 .

[0180] The formation methods of the hole transport layer 5, the light emitting layer 6, the electron transport layer 7, and the electron injection layer 8 are not particularly limited, and various conventionally known formation methods can be appropriately used according to the properties of the materials used for the hole transport layer 5, the light emitting layer 6, the electron transport layer 7, and the electron injection layer 8.

[0181] Specifically, as methods for forming the hole transport layer 5, the light-emitting layer 6, the electron transport layer 7, and the electron injection layer 8, there can be cited a coating method of an organic compound solution containing organic compounds constituting the hole transport layer 5, the light-emitting layer 6, the electron transport layer 7, and the electron injection layer 8, a vacuum evaporation method, an ESDUS (Evaporative Spray Deposition from Ultra-dilute Solution) method, and the like.

[0182] When the hole transport layer 5, the light-emitting layer 6, the electron transport layer 7, and the electron injection layer 8 are formed by a coating method, the organic compounds constituting the hole transport layer 5, the light-emitting layer 6, the electron transport layer 7, and the electron injection layer 8 are dissolved in a solvent respectively to form an organic compound solution containing the organic compounds constituting the hole transport layer 5, the light-emitting layer 6, the electron transport layer 7, and the electron injection layer 8 respectively.

[0183] As solvents for dissolving organic compounds constituting the hole transport layer 5, the light-emitting layer 6, the electron transport layer 7, and the electron injection layer 8, for example, preferred are aromatic hydrocarbon solvents such as xylene, toluene, cyclohexylbenzene, dihydrobenzofuran, trimethylbenzene, tetramethylbenzene, aromatic heterocyclic compound solvents such as pyridine, pyrazine, furan, pyrrole, thiophene, methylpyrrolidone, and aliphatic hydrocarbon solvents such as hexane, pentane, heptane, cyclohexane, and the like, and they can be used alone or in combination.

[0184] As a method for coating an organic compound solution containing an organic compound constituting the hole transport layer 5, the light emitting layer 6, the electron transport layer 7, and the electron injection layer 8, various coating methods such as spin coating, casting, micro gravure coating, gravure coating, rod coating, roll coating, wire rod coating, dip coating, spray coating, screen printing, flexographic printing, offset printing, and inkjet printing can be used. Among these coating methods, spin coating and slit coating are preferably used from the aspect of easier control of film thickness.

[0185] Next, the cathode 9 is formed.

[0186] The cathode 9 can be formed in the same manner as the anode 3 , for example.

[0187] Through the above process, we can obtain Figure 1 The organic electroluminescent element 1 is shown.

[0188] [Sealing method]

[0189] In the right Figure 1 When the organic electroluminescent element 1 shown is sealed, the sealing can be performed by using a conventional method used for sealing an organic electroluminescent element.

[0190] The organic electroluminescent element 1 of this embodiment has excellent electron injection property because the phenanthroline compound forms a coordination bond with the adjacent cathode material to generate negative charge, so that the electron injection and electron transfer from the cathode 9 to the light-emitting layer 6 are fast and the driving voltage is low.

[0191] In addition, as described above, the organic thin film comprising the phenanthroline compound and the second material is a laminated film, and the layer formed by the second material is a layer different from the electron injection layer formed by the first material. The organic electroluminescent element of such an embodiment also becomes an organic electroluminescent element 1 with a fast speed of electron injection and electron transfer from the cathode 9 to the light-emitting layer 6 and a low driving voltage.

[0192] [Other examples]

[0193] The organic electroluminescent element of the present invention is not limited to the organic electroluminescent element described in the above embodiment.

[0194] Specifically, the above embodiment is described by taking the case where the organic thin film functions as an electron injection layer as an example, but the organic electroluminescent element of the present invention only needs to have an organic thin film between the cathode and the light-emitting layer. Therefore, the organic thin film is not limited to the electron injection layer, and can also be set as a layer that serves as both an electron injection layer and an electron transport layer, and can also be set as an electron transport layer.

[0195] in addition, Figure 1 In the organic electroluminescent element 1 shown, the electron transport layer 7 , the hole transport layer 5 , and the hole injection layer 4 may be formed as required or may not be provided.

[0196] Furthermore, each of the anode 3 , the hole injection layer 4 , the hole transport layer 5 , the light emitting layer 6 , the electron transport layer 7 , the electron injection layer 8 , and the cathode 9 may be formed of one layer or two or more layers.

[0197] in addition, Figure 1 In the organic electroluminescent element 1 shown, Figure 1 Other layers are provided between the layers shown. Specifically, a hole blocking layer or the like may be provided as necessary for the purpose of further improving the characteristics of the organic electroluminescent element.

[0198] As described above, the phenanthroline compound of the present invention has extremely excellent electron injection properties, so when used in the electron injection layer 8, electrons can be directly injected even for the material used in the light-emitting layer 6. Therefore, even if the material used in the light-emitting layer 6 is used for the electron transport layer 7, it can be operated at a low driving voltage. Therefore, even if the material used in the light-emitting layer 6 is used for the electron transport layer 7, the organic EL element 1 of a simple structure can be operated at a low driving voltage. In this case, compared with a representative organic EL element, one material used can be reduced.

[0199] Therefore, when the phenanthroline compound of the present invention is used for the electron injection layer 8 and the second material is used for the electron transport layer 7, the second material can also be used in the light emitting layer 6. In other words, the embodiment in which the light emitting layer 6 contains the second material is also a preferred embodiment of the organic EL device of the present invention.

[0200] In addition, since it is relatively easy to inject holes from the hole injection layer 4 into the material used in the light-emitting layer 6, when the phenanthroline compound of the present invention is used for the electron injection layer 8, even if the material used in the light-emitting layer 6 is used for the hole transport layer 5, it is possible to operate at a low driving voltage. Therefore, even an organic EL element 1 having a simple structure in which the material used in the light-emitting layer 6 is used for the electron transport layer 7 and the hole transport layer 5 can operate at a low driving voltage. In this case, compared with a typical organic EL element, two materials used can be reduced.

[0201] Therefore, when the phenanthroline compound of the present invention is used for the electron injection layer 8 and the second material is used for the electron transport layer 7, the second material can also be used in the light-emitting layer 6 and the hole transport layer 5. In other words, the light-emitting layer 6 includes the second material, which is also a preferred embodiment of the organic EL element of the present invention. In addition, the layer (e.g., the hole transport layer 5) including the second material between the anode 3 and the light-emitting layer 6 is also a preferred embodiment of the organic EL element of the present invention.

[0202] In addition, in the above embodiment, an organic EL element having a conventional structure in which an anode 3, a light-emitting layer 6, and a cathode 9 are sequentially arranged on a substrate 2 is taken as an example for explanation, but an element having an inverted structure in which a cathode 9 is arranged between the substrate 2 and the light-emitting layer 6 may also be used (for example, see Figure 2 ).

[0203] in addition, Figure 2 In the organic EL element shown, the inorganic oxide layer 10 , the electron transport layer 7 , the hole transport layer 5 , and the hole injection layer 4 may be formed as required or may not be provided.

[0204] [Display device, lighting device]

[0205] The organic electroluminescent element of the present invention can change the emission color by appropriately selecting the material of the light-emitting layer, etc., and can also obtain the desired emission color by using a color filter, etc. Therefore, it can be suitably used as a light-emitting part of a display device or a lighting device.

[0206] The display device of the present invention includes the organic electroluminescent element of the present invention having an organic thin film between a cathode and a light-emitting layer, and has excellent productivity and low driving voltage. Therefore, it is suitable as a display device.

[0207] Furthermore, the lighting device of the present invention includes the organic electroluminescent element of the present invention which has excellent productivity and low driving voltage, and is therefore suitable as a lighting device.

[0208] [Organic thin film solar cells, thin film transistors]

[0209] The present invention is not limited to the above-mentioned embodiments, and the organic thin film of the present invention can be used in devices such as organic thin film solar cells and thin film transistors.

[0210] The organic thin film solar cell of the present invention comprises the organic thin film of the present invention. For example, when the organic thin film is used for the electron injection layer of the organic thin film solar cell, a negative charge is generated by forming a hydrogen bond between the phenanthroline compound of the present invention and the second material, so that the speed of electron transmission is fast and high power generation efficiency can be obtained. Therefore, it is preferred as an organic thin film solar cell.

[0211] In addition, the thin film transistor of the present invention includes an organic thin film. For example, when the channel layer of the thin film transistor is formed of an organic thin film, a channel layer with high electron mobility can be obtained.

[0212] Furthermore, when the organic thin film is formed on an electrode, it is expected that the contact resistance can be reduced.

[0213] Example

[0214] The present invention is further described in detail with reference to the following examples, but the present invention is not limited to these examples. It should be noted that, unless otherwise specified, "parts" means "parts by mass" and "%" means "% by mass".

[0215] [Example 1] Synthesis of Compound (1-1)

[0216] [Chemistry 5]

[0217]

[0218] Add 10.4 g of Michaelis acid and 90 mL of methyl orthoformate to a flask, and heat and stir at 130°C for 2 hours. Cool to 70°C, add 5.0 g of 1,2-diaminonaphthalene, and heat and stir at 130°C for 2 hours. After cooling naturally to room temperature, filter out the precipitated solid, wash with diethyl ether, and dry under vacuum to obtain 12.5 g of compound (1-1-1). Add (1-1-1) little by little into diphenyl ether heated to 220°C, and continue heating and stirring for 30 minutes. After cooling naturally to room temperature, add acetone, filter out the precipitated solid, wash with acetone, and obtain 3.8 g of (1-1-2) as a brown solid.

[0219] The obtained (1-1-2) and 65 mL of phosphorus oxychloride were added to a flask, and heated and stirred at 120°C for 1 hour under a nitrogen atmosphere. The phosphorus oxychloride was distilled off under reduced pressure, and chloroform was added to the residue, which was then placed in a sodium carbonate aqueous solution. The organic layer was concentrated and purified by column chromatography to obtain 1.7 g of (1-1-3).

[0220] 1.66 g of (1-1-3) and 9.1 mL of pyrrolidine were added to a flask, and the mixture was stirred under heating at 100° C. for 30 minutes. The mixture was cooled to room temperature and concentrated, and the resulting residue was purified by column chromatography to obtain 1.47 g of (1-1).

[0221] The obtained (1-1) 1 The results of H-NMR measurement are as follows.

[0222] 1H-NMR (600MHz, CDCl3) δ1.62(s,1H),1.93(brs,2H),1.98-2.14(m,2H),2.87(brs,2H),3.75(b rs, 2H), 6.93 (d, J = 5.58Hz, 1H), 7.36-7.40 (m, 1H), 8.18-8.21 (m, 1H), 8.68 (d, J = 5.19Hz, 1H).

[0223] [Example 2] Synthesis of Compound (1-2)

[0224] [Chemistry 6]

[0225]

[0226] 10 g of 4-bromo-2-nitroaniline, 8.7 g of 2-naphthaleneboronic acid, 41.06 g of Pd(PPh3), 14.7 g of sodium carbonate, 100 mL of toluene, 100 mL of distilled water, and 50 mL of ethanol were added to a flask and stirred at 90°C for 6 hours. After the reaction solution was naturally cooled to room temperature, water and heptane were added and stirred. The precipitated solid was filtered, rinsed with water, methanol, and diethyl ether, and vacuum dried to obtain 12.0 g of a brown solid (1-2-1).

[0227] 9.0 g of (1-2-1), 0.45 g of 10% Pd-C, 90 mL of ethanol, and 60 mL of THF were added to a flask, and 11.3 mL of 6N hydrochloric acid was added while stirring. The mixture was stirred for 36 hours under a hydrogen atmosphere. After adding water to the suspension, the pH was adjusted to 10 with a 4N aqueous sodium hydroxide solution, and extracted with ethyl acetate. The organic layers were combined, washed with water and saturated brine, and dried with potassium carbonate powder. Filtered and concentrated to obtain 9.4 g of a reddish brown solid (1-2-2).

[0228] Add 12.8 mmol of Michaelis acid and 133 mL of methyl orthoformate to a flask, and heat and stir at 130°C for 2 hours. Cool to 70°C, add 9.4 g of (1-2-2), and then heat and stir at 130°C for 2 hours. After cooling naturally to room temperature, filter out the precipitated solid, wash with diethyl ether, and vacuum dry to obtain 17.4 g of compound (1-2-3). Add (1-2-3) little by little into diphenyl ether heated to 240°C, and continue heating and stirring for 30 minutes. After cooling naturally to room temperature, add acetone, filter out the precipitated solid, wash with acetone, and obtain 3.2 g of (1-2-4) as a brown solid.

[0229] The obtained (1-2-4) and 50 mL of phosphorus oxychloride were added to a flask, and heated and stirred at 100°C for 1 hour under a nitrogen atmosphere. The phosphorus oxychloride was distilled off under reduced pressure, and chloroform was added to the residue, which was then placed in a sodium carbonate aqueous solution. The organic layer was concentrated and purified by column chromatography to obtain 1.7 g of (1-2-5).

[0230] 1.66 g of (1-2-5) and 9.1 mL of pyrrolidine were added to a flask, and the mixture was heated and stirred at 100°C for 30 minutes. The mixture was cooled to room temperature and concentrated, and the resulting residue was purified by column chromatography to obtain 1.28 g of (1-2).

[0231] The obtained (1-2) 1 The results of H-NMR measurement are as follows.

[0232] 1 H-NMR (600MHz, CDCl3) δ2.07-2.15(m,4H),2.96(brs,4H),3.77-3.84(m,4H),6.73(d,J=5.58Hz,1H),6.94(d,J=4.99Hz,1H),7.45-7.52(m,2H),7 .58(dd,J=8.51,1.76Hz,1H)7.77(d,J=8.51Hz,1H),7.83-7.90(m,2H),7 .96(s,1H),7.99(s,1H),8.74(d,J=5.58Hz,1H),8.84(d,J=5.28Hz,1H).

[0233] [Example 3] Synthesis of Compound (1-3)

[0234] [Chemistry 7]

[0235]

[0236] 10 g of methyl 2-formyl-2-phenylacetate, 2.73 g of 1,2-phenylenediamine, and 76 mL of dichloromethane were added to a flask and stirred overnight at room temperature. The reaction solution was concentrated, 50 mL of phosphorus oxychloride was added to the obtained residue, and the mixture was heated and stirred at 100°C for 5 hours. The phosphorus oxychloride was distilled off under reduced pressure, chloroform was added, and the mixture was separated and washed with an aqueous sodium carbonate solution. The organic layer was concentrated and purified by column chromatography to obtain 3.6 g of (1-3-1).

[0237] The obtained (1-3-1) and 100 mL of pyrrolidine were added to a flask and stirred at 100°C overnight. After cooling naturally to room temperature, water was added, and the precipitated solid was filtered out and dissolved in chloroform. The solid was transferred to a separatory funnel, washed with water and saturated brine, and dried over sodium sulfate. The mixture was filtered and concentrated, and the residue was purified by column chromatography to obtain 1.8 g of (1-3).

[0238] The obtained (1-3) 1 The results of H-NMR measurement are as follows.

[0239] 1 H-NMR (600MHz, CDCl3) δ1.78-2.04(m,4H),3.10-3.44(m,4H),7.34-7.56(m,3H),7.43(brd,J=1.47Hz,1H),7.44(brs,1H),8.01(s,1H),8.84(s,1H).

[0240] [Example 4] Synthesis of Compound (1-4)

[0241] [Chemistry 8]

[0242]

[0243] 16.6 mmol of 2-bromonaphthalene and 100 mL of diethyl ether were added to a flask, and 100 mL of tert-butyl lithium was added dropwise at -78°C. After the addition was completed, the mixture was stirred at the same temperature for 1 hour, and then 500 mL of toluene was added. 5.0 g of 4,7-dichlorophenanthroline was added, the temperature was raised to 0°C, and the mixture was stirred overnight. Water was added, the mixture was extracted with chloroform, and the organic layer was dried over sodium sulfate, filtered, and concentrated. The residue was dissolved in 300 mL of dichloromethane, 52.4 g of manganese dioxide was added, and the mixture was stirred at room temperature for 2 hours. Celite was filtered, the filtrate was concentrated, and the residue obtained was passed through a short silica gel column and then concentrated. Methanol was added to the residue, and the precipitated solid was filtered out. It was washed with methanol to obtain 7.5 g of (1-4-1).

[0244] The obtained (1-4-1) and 100 mL of pyrrolidine were added to a flask and stirred overnight at 100° C. After cooling to room temperature, water was added, and the precipitated solid was filtered out and washed with methanol and then with chloroform to obtain 5.0 g of (1-4).

[0245] The obtained (1-4) 1 The results of H-NMR measurement are as follows.

[0246] 1H-NMR (600MHz, CDCl3) δ2.14 (dt, J=6.16, 3.37Hz, 4H), 3.82-3.88 (m, 4H), 7.43-7.46 (m, 1H) 7.51-7 .57(m,2H),7.92(d,J=7.92Hz,1H),8.02-8.09(m,3H),8.69(dd,J=8.51,1.47Hz,1H),8.96(s,1H).

[0247] [Example 5] Compound (1-5)

[0248] [Chemistry 9]

[0249]

[0250] 2.1 g of 3-bromobiphenyl and 10 mL of diethyl ether were added to a flask, and 3.3 mL of n-butyl lithium was added dropwise at -78°C. After the addition was completed, the mixture was stirred at the same temperature for 1 hour, and then 50 mL of toluene was added. After 0.55 g of 4,7-dichlorophenanthroline was added, the temperature was raised to 0°C, and the mixture was stirred overnight. Water was added, the mixture was extracted with chloroform, and the organic layer was dried over sodium sulfate, filtered, and concentrated. The residue was dissolved in 30 mL of dichloromethane, 5.8 g of manganese dioxide was added, and the mixture was stirred at room temperature for 2 hours. Filtered with diatomaceous earth, the filtrate was concentrated, and the residue was passed through a short silica gel column and then concentrated. Methanol was added to the residue, and the precipitated solid was filtered out. It was washed with methanol to obtain 1.15 g of (1-5-1).

[0251] This was dissolved in 3.0 g of pyrrolidine and stirred overnight at 100° C. After cooling to room temperature, water was added, and the precipitated solid was filtered out and washed with methanol to obtain 0.74 g of (1-5).

[0252] The obtained (1-5) 1 The results of H-NMR measurement are as follows.

[0253] 1 H-NMR (600MHz, CDCl3) δ8.65(t,J=1.6Hz,2H),8.53-8.42(m,2H),8.00(s,2H),7.79(dd,J=1.0,8.1Hz,4H),7.68(td,J=1.2,7 .8Hz,2H),7.60(t,J=7.6Hz,2H),7.47(t,J=7.7Hz,4H),7.42-7.35(m,2H),7.32(s,2H),3.87-3.75(m,8H),2.18-2.04(m,8H).

[0254] [Example 6] Synthesis of Compound (1-6)

[0255] [Chemistry 10]

[0256]

[0257] (1-6) was synthesized by the same operation as in Example 5 using 2.4 g of 2-bromo-9,9-dimethylfluorene instead of 3-bromobiphenyl. The yield was 0.63 g.

[0258] The obtained (1-6) 1 The results of H-NMR measurement are as follows.

[0259] 1 H-NMR (600MHz, CDCl3) δ8.58(s,2H),8.32(dd,J=1.5,7.9Hz,2H),8.00(s,2H),7.86(d,J=7.9Hz,2H),7.81(d,J=6.7Hz,2H),7 .50(d,J=6.7Hz,2H),7.43-7.31(m,2H),7.33(s,2H),6.98(s,2H),3.81(brt,J=6.3Hz,8H),2.18-2.06(m,8H),1.43(s,12H).

[0260] [Comparative Example 1] Synthesis of Comparative Compound 1 (4,7-di(pyrrolidin-1-yl)-1,10-phenanthroline)

[0261] With reference to Synthesis Example 4 of Patent Document 1 (International Publication No. 2021 / 045179), 4,7-di(pyrrolidin-1-yl)-1,10-phenanthroline was obtained.

[0262] [Comparative Example 2] Synthesis of Comparative Compound 2 (2,9-butyl-4,7-di(pyrrolidin-1-yl)-1,10-phenanthroline)

[0263] [Chemistry 11]

[0264]

[0265] Under a nitrogen atmosphere, a suspension of 3.0 g of 4,7-dichlorophenanthroline in 120 mL of toluene was stirred while 30 mL of n-butyl lithium was added dropwise at 0°C. Stir overnight at this temperature, quench with water, and extract with chloroform. The organic layer was washed with saturated brine, dried over sodium sulfate, filtered, and concentrated. The obtained residue was dissolved in 120 mL of dichloromethane, 12 g of manganese dioxide was added, and stirred at room temperature for 2 hours. Filter, concentrate the filtrate, and purify by column chromatography to obtain 3.0 g of 2,9-dibutyl-4,7-dichlorophenanthroline.

[0266] The obtained 2,9-dibutyl-4,7-dichlorophenanthroline was dissolved in 50 mL of pyrrolidine, stirred at 100° C. overnight, and then poured into water, and the precipitated solid was filtered out. The filtered solid was purified by column chromatography to obtain 2.4 g of 2,9-butyl-4,7-di(pyrrolidin-1-yl)-1,10-phenanthroline as comparative compound 2.

[0267] The obtained 2,9-butyl-4,7-di(pyrrolidin-1-yl)-1,10-phenanthroline 1 The results of H-NMR measurement are as follows.

[0268] 1 H-NMR(600MHz, CDCl3)δ1.00(t,J=7.34Hz,3H),1.52(sxt,J=7.39Hz,2H),1.84-1.91(m, 2H),2.01-2.08(m,4H),3.04-3.09(m,2H),3.62-3.69(m,4H),6.65(s,1H),7.87(s,1H).

[0269] Table 1 shows the glass transition temperatures and melting points of the phenanthroline compounds of the present invention synthesized in Examples 1 to 6 and Comparative Compounds 1 and 2 synthesized in Comparative Examples 1 and 2.

[0270] [Table 1]

[0271]

[0272] [Example 7] Preparation of Organic EL Element 1

[0273] An organic EL device was produced by the method shown below.

[0274] A transparent glass substrate having an ITO pattern with a thickness of 50 nm as an anode was prepared, and was cleaned and dried by a conventional method.

[0275] On the ITO of the substrate, a hole injection layer with a thickness of 30 nm, a hole transport layer with a thickness of 65 nm, an electron blocking layer with a thickness of 5 nm, a light-emitting layer with a thickness of 22 nm, a hole blocking layer with a thickness of 10 nm, and an electron transport layer with a thickness of 30 nm are formed in sequence.

[0276] A film with a thickness of 1 nm consisting of the compound of the present invention (1-1) is further formed as an electron injection layer. A film formation of a cathode with a thickness of 100 nm consisting of silver and magnesium is performed thereon. At this time, silver is made to be 10% by mass relative to the entire cathode. Finally, the substrate with each layer formed to the cathode is sealed to obtain an organic EL element 1.

[0277] [Examples 8 to 10, Comparative Examples 3 and 4] Preparation of Organic EL Elements 2 to 6

[0278] In the same manner as in Example 7, organic EL devices 2 to 6 were prepared using compounds (1-2), (1-3), (1-4), Liq (8-hydroxyquinolinolatolithium), and comparative compound 1 in the electron injection layer.

[0279] The driving voltage, luminance, current efficiency and life of the organic EL devices 1 to 6 were measured by the following methods.

[0280] <Measurement of Light Emitting Characteristics of Organic Components>

[0281] Voltage was applied to the device using "6240 SourceMeter" manufactured by ADC, and the light emission brightness was measured using "BM-9" manufactured by Topcon.

[0282] The current efficiency was calculated from the luminance and the current value at the voltage applied to each element.

[0283] Lifespan: from initial brightness 1000cd / cm 2 The time it takes for the energy to decay by 90%.

[0284] [Table 2]

[0285]

[0286] From the results in Table 1, it is understood that the phenanthroline compound of the present invention has a glass transition temperature that is 20° C. or higher than that of Comparative Compound 1, which is a phenanthroline compound having no substituent, and a comparative compound having an alkyl group as a substituent.

[0287] On the other hand, it can be confirmed from the results of Table 2 that the organic EL element using the phenanthroline compound of the present invention has the same level of characteristics as the commonly used electron injection material Liq and the comparative compound 2. Therefore, by using the phenanthroline compound of the present invention, the durability can be improved while maintaining the good characteristics of the organic EL element.

[0288] Industrial Applicability

[0289] The organic thin film of the present invention can be used for an organic electroluminescent element, a display device, a lighting device, an organic thin film solar cell, a photoelectric conversion element, a thin film transistor, and the like.

[0290] Description of the label

[0291] 1: Organic EL components

[0292] 2: Substrate

[0293] 3: Anode

[0294] 4: Hole injection layer

[0295] 5: Hole transport layer

[0296] 6: Luminous layer

[0297] 7: Electron transport layer

[0298] 8: Electron injection layer

[0299] 9: Cathode

[0300] 10: Oxide layer

Claims

1. A phenanthroline compound represented by the following general formula (1): [Chemistry 1] In the general formula (1), R 1a ~R 1d R independently represents a hydrogen atom, an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent; 2a , R 2b R independently represents a dialkylamino group which may or may not form a ring structure and may or may not have a substituent; 3a , R 3b independently represent a hydrogen atom, an aromatic hydrocarbon group which may be substituted, an aromatic heterocyclic group which may be substituted, -R 4 =R 5 -R 6 , -R 7 -R 8 , or R 3a , R 3b The fused ring structure formed by bonding, -R 4 =R 5 -R 6 In, R 4 , R 5 Indicates CH or N, R 6 represents a hydrogen atom, an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent, -R 7 -R 8 In, R 7 Indicates CH2, NH, O, S, R 8 represents a hydrogen atom, an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent; R 1a ~R 1d , R 3a , R 3b At least one of them is an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent. An organic thin film comprising the phenanthroline compound according to claim 1 . 3 . An organic semiconductor device material comprising the phenanthroline compound according to claim 1 .

4. The organic semiconductor device material according to claim 3, wherein The organic semiconductor element is any one of an organic electroluminescent element, an organic transistor, a photoelectric conversion element, and an organic solar cell. An organic semiconductor device comprising the phenanthroline compound according to claim 1 .

6. The organic semiconductor device according to claim 5, wherein The organic semiconductor element is any one of an organic electroluminescent element, an organic transistor, a photoelectric conversion element, and an organic solar cell. 7 . An image display device or lighting fixture comprising the organic semiconductor element according to claim 5 or 6 .

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