Fused ring compound, its production method, and material for organic electroluminescent device

Abstract

To provide a fused ring compound that contributes to the making of an organic electroluminescent element having excellent drive voltage.SOLUTION: The problem has been achieved by a fused ring compound having a particular structure represented by the formula (1).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a fused ring compound, a method for producing the same, and a material for an organic electroluminescent device containing the same. [Background technology]

[0002] Organic electroluminescent devices are used not only for small displays but also for large televisions, lighting, and the like, and their development is being actively pursued.

[0003] In recent years, market demand for organic electroluminescent devices has been increasing, and materials with excellent current efficiency, driving voltage, and long life characteristics are required. Under these circumstances, the possibility of using various polycyclic compounds as the core of new materials has been explored and examined. As a polycyclic compound, Non-Patent Document 1 does not report any findings on organic electroluminescence, but discloses benz[g]indeno[1,2,3-qr]chrysene. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Angewandte Chemie, International Edition, 2017, 56, p. 12224-12228. Summary of the Invention [Problem to be solved by the invention]

[0005] An object of one embodiment of the present invention is to propose a compound having a new mother nucleus, while various polycyclic compounds are being explored and examined for their potential as the mother nucleus of new materials.

[0006] Another aspect of the present invention is to provide a benz[g]indeno[1,2,3-qr]chrysene compound, a material for an organic electroluminescent device, and an electron transport material for an organic electroluminescent device, which are useful for producing an organic electroluminescent device with a low driving voltage. Another aspect of the present invention is to provide an organic electroluminescent device with a low driving voltage. [Means for solving the problem]

[0007] According to one aspect of the present invention, there is provided a fused ring compound represented by formula (1).

[0008] [ka]

[0009] In formula (1), A 1 ~A 5 each independently represents a charge transport group; k1 to k3 each independently represent an integer of 0 or more and 4 or less; k4 is an integer between 0 and 3; k5 is an integer between 0 and 1; The sum of k1 to k5 is an integer of 1 or more; Multiple A's 1 ~A 5 may be the same or different.

[0010] According to another aspect of the present invention, there is provided a material for an organic electroluminescent device, comprising a fused ring compound represented by the following formula (1'):

[0011] [ka] In formula (1'), A 1 ~A 5 each independently represents a charge transport group; k1 to k3 each independently represent an integer of 0 or more and 4 or less; k4 is an integer between 0 and 3; k5 is an integer between 0 and 1; Multiple A's 1 ~A 5 may be the same or different.

[0012] According to another aspect of the present invention, there is provided an electron transport material for an organic electroluminescent device, which comprises a fused ring compound represented by the above formula (1'). According to another aspect of the present invention, there is provided an organic electroluminescent device comprising a fused ring compound represented by the above formula (1'). Effect of the Invention

[0013] According to one aspect of the present invention, it is possible to provide a fused ring compound, a material for an organic electroluminescent element, and an electron transport material for an organic electroluminescent element, which are useful for producing an organic electroluminescent element having an excellent driving voltage.

[0014] According to another aspect of the present invention, an organic electroluminescence device having an excellent driving voltage can be provided. A method for producing a fused ring compound according to another embodiment of the present invention is a method for producing the above-mentioned fused ring compound, which comprises intramolecular cyclization of a compound represented by formula (3).

[0015] [ka] In formula (3), A 1 ~A 5 each independently represents a charge transport group; k1 to k3 each independently represent an integer of 0 or more and 4 or less; k4 is an integer between 0 and 3; k5 is an integer between 0 and 1; The sum of k1 to k5 is an integer of 1 or more; Multiple A's 1 ~A 5 may be the same or different; T represents the following formula (4) or (4');

[0016] [ka] In formulas (4) and (4'), R 1 ~R 9 represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of a layered structure of an organic electroluminescent device including a fused ring compound according to one embodiment of the present invention. [Diagram 2] FIG. 1 is a schematic cross-sectional view showing an example of a layered structure of an organic electroluminescent device containing a fused ring compound according to one embodiment of the present invention (Device Example 1). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, the fused ring compound according to one embodiment of the present invention will be described in detail.

[0019] <Benzindenochrysene compounds> A fused ring compound according to one embodiment of the present invention is represented by formula (1).

[0020] [ka]

[0021] In formula (1), A 1 ~A 5 each independently represents a charge transport group; k1 to k3 each independently represent an integer of 0 or more and 4 or less; k4 is an integer between 0 and 3; k5 is an integer between 0 and 1; The sum of k1 to k5 is an integer of 1 or more; Multiple A's 1 ~A 5 may be the same or different.

[0022] The definition of the charge transport group in the fused ring compound (1) and preferred specific examples thereof are as follows.

[0023] <Charge transport group> A charge transporting group is a substituent that has the function of transporting a charge, which can be a hole, an electron, or both.

[0024] Examples of the charge transporting group include the following substituents (a-1) to (a-17). (a-1) a deuterium atom, (a-2) a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, (a-3) a trifluoromethyl group, (a-4) a pentafluoroethyl group, (a-5) a cyano group, (a-6) a nitro group, (a-7) hydroxyl group, (a-8) a thiol group, (a-9) a monocyclic, linked or fused ring aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent; (a-10) a monocyclic, linked or fused ring heteroaromatic group having 3 to 36 carbon atoms which may have a substituent; (a-11) a phosphine oxide group which may have a substituent, (a-12) a silyl group which may have a substituent, (a-13) a boronyl group which may have a saturated hydrocarbon group having 2 to 10 carbon atoms, (a-14) a linear or branched alkyl group having 1 to 18 carbon atoms, (a-15) a linear or branched alkoxy group having 1 to 18 carbon atoms, (a-16) a trifluoromethylsulfonyloxy group, or (a-17) A group represented by formula (2) or (2'):

[0025] [ka] During the ceremony, R1 ~R 3 are each independently (r-1) a hydrogen atom, (r-2) a deuterium atom, (r-3) a monocyclic, linked or fused ring aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent; (r-4) a monocyclic, linked or fused ring heteroaromatic group having 3 to 36 carbon atoms which may have a substituent, or (r-5) represents a linear or branched alkyl group having 1 to 18 carbon atoms; L is independently a phenylene group which may be substituted with a methyl group or a phenyl group; a naphthylene group optionally substituted with a methyl group or a phenyl group; a biphenylene group which may be substituted by a methyl group or a phenyl group, or represents a single bond; n represents 1 or 2; When L is a single bond, n is 1; when L is not a single bond, n is 1 or 2; If n is 2, multiple R 1 ~R 2 may be the same or different.

[0026] <Regarding (a-9)> Examples of the monocyclic, linked, or fused aromatic hydrocarbon group having 6 to 30 carbon atoms (a-9) include a phenyl group, a biphenylyl group, a terphenylyl group, a naphthyl group, a fluorenyl group, an anthryl group, a phenanthryl group, a benzofluorenyl group, a triphenylenyl group, a spirobifluorenyl group, a diphenylfluorenyl group, a dibenzo[g,p]chrysenyl group, etc. The monocyclic, linked, or fused aromatic hydrocarbon group having 6 to 30 carbon atoms is preferably a monocyclic, linked, or fused aromatic hydrocarbon group having 6 to 18 carbon atoms.

[0027] In addition, when the aromatic hydrocarbon group of (a-9) has a substituent, the substituent is preferably each independently a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, a hydroxyl group, a thiol group, a phosphine oxide group which may have a substituent, a silyl group which may have a substituent, a boronyl group which may have a saturated hydrocarbon group having 2 to 10 carbon atoms, a linear or branched alkyl group having 1 to 18 carbon atoms, a linear or branched alkoxy group having 1 to 18 carbon atoms, or a trifluoromethylsulfonyloxy group.

[0028] The phosphine oxide group may be an unsubstituted phosphine oxide group or a phosphine oxide group having a substituent. A phosphine oxide group having a substituent is preferred.

[0029] The phosphine oxide group having a substituent is preferably a phosphine oxide group having a monocyclic, linked or condensed aromatic hydrocarbon group having 6 to 18 carbon atoms, or a condensed heteroaromatic group. Specific examples include groups substituted with two aryl groups, such as diphenylphosphine oxide.

[0030] The silyl group may be an unsubstituted silyl group or a substituted silyl group, and is preferably a substituted silyl group.

[0031] The silyl group having a substituent is preferably a silyl group having a monocyclic, linked, or fused aromatic hydrocarbon group having 6 to 18 carbon atoms, or a fused heteroaromatic group. Specific examples include groups substituted with three aryl groups, such as a triphenylsilyl group.

[0032] Examples of the boronyl group which may have a saturated hydrocarbon group having 2 to 10 carbon atoms include a dihydroxyboryl group (-B(OH)2), a 4,4,5,5-tetramethyl-[1,3,2]-dioxaborolanyl group, and a 5,5-dimethyl-[1,3,2]-dioxaborinane group.

[0033] Examples of the linear or branched alkyl group having 1 to 18 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an n-hexyl group, a cyclohexyl group, an octyl group, a decyl group, a dodecyl group, and an octadecyl group.

[0034] Examples of the linear or branched alkoxy group having 1 to 18 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group, a pentyloxy group, an n-hexyloxy group, a cyclohexyloxy group, an octyloxy group, a decyloxy group, a dodecyloxy group, and an octadecyloxy group.

[0035] <About (a-10)> The (a-10) monocyclic, linked or fused ring heteroaromatic group having 3 to 36 carbon atoms is a monocyclic, linked or fused ring heteroaromatic group having 3 to 36 carbon atoms and containing at least one atom selected from the group consisting of an oxygen atom, a nitrogen atom, and a sulfur atom on the aromatic ring.

[0036] Examples of the heteroaromatic group include a pyrrolyl group, a thienyl group, a furyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridyl group, a phenylpyridyl group, a pyridylphenyl group, a pyrimidyl group, a pyrazyl group, a 1,3,5-triazyl group, a 1,3,5-triazylphenyl group, a 1,3,5-triazylbiphenylyl group, a 4,6-diphenyl-1,3,5-triazyl group, an indolyl group, a benzothienyl group, a benzofuranyl group, a benzimidazolyl group, Examples of such groups include an indazolyl group, a benzothiazolyl group, a benzoisothiazolyl group, a 2,1,3-benzothiadiazolyl group, a benzoxazolyl group, a benzoisoxazolyl group, a 2,1,3-benzoxadiazolyl group, a quinolyl group, an isoquinolyl group, a quinoxalyl group, a quinazolyl group, a carbazolyl group, a 9-phenylcarbazolyl group, a 9-(4-biphenylyl)carbazolyl group, a dibenzothienyl group, a dibenzofuranyl group, a phenoxazinyl group, a phenothiazinyl group, a phenazine group, and a thianthrenyl group.

[0037] In addition, when the heteroaromatic group of (a-10) has a substituent, it is preferable that the substituent is each independently a cyano group, a fluorine atom, a trifluoromethyl group, a linear or branched alkyl group having 1 to 18 carbon atoms, a linear or branched alkoxy group having 1 to 18 carbon atoms, or a trifluoromethylsulfonyloxy group.

[0038] Examples of the linear or branched alkyl group having 1 to 18 carbon atoms include the same linear or branched alkyl group having 1 to 18 carbon atoms as exemplified in the above-mentioned (a-9). Examples of the linear or branched alkoxy group having 1 to 18 carbon atoms include the same linear or branched alkoxy group having 1 to 18 carbon atoms as exemplified in the above-mentioned (a-9).

[0039] <About (a-11)> The phosphine oxide group (a-11) may be an unsubstituted phosphine oxide group or a phosphine oxide group having a substituent. A phosphine oxide group having a substituent is preferred. Examples of the phosphine oxide group having a substituent include the same phosphine oxide groups as exemplified in (a-9) above.

[0040] <Regarding (a-12)> The silyl group (a-12) may be an unsubstituted silyl group or a silyl group having a substituent. A silyl group having a substituent is preferable. Examples of the silyl group having a substituent include the same silyl groups as those exemplified in the above-mentioned (a-9).

[0041] <About (a-13)> Examples of the (a-13) boronyl group which may have a saturated hydrocarbon group having 2 to 10 carbon atoms and the boronyl group which may have a saturated hydrocarbon group having 2 to 10 carbon atoms include the same boronyl groups as exemplified in the above-mentioned (a-9).

[0042] <Regarding (a-14)> Examples of the linear alkyl group having 1 to 18 carbon atoms as (a-14) include the same linear or branched alkyl groups having 1 to 18 carbon atoms as exemplified above as (a-9).

[0043] <About (a-15)> Examples of the linear or branched alkoxy group having 1 to 18 carbon atoms (a-15) include the same linear or branched alkoxy groups having 1 to 18 carbon atoms as exemplified in the above-mentioned (a-9).

[0044] <About (a-17)> (a-17) is a group represented by formula (2) or (2'), and as described above, the charge transport group may be a group represented by the above formula (2) or (2'). In formula (2) and (2'), L, R 1 ~R 3 , n is defined as follows:

[0045] <Regarding formulas (2) and (2')> In formulas (2) and (2'), R 1 ~R 3 each independently represents: (r-1) a hydrogen atom; (r-2) a deuterium atom; (r-3) an optionally substituted monocyclic, linked or fused aromatic hydrocarbon group having 6 to 30 carbon atoms; (r-4) an optionally substituted monocyclic, linked or fused aromatic heteroaromatic group having 3 to 36 carbon atoms; or (r-5) a linear or branched alkyl group having 1 to 18 carbon atoms. R 1 ~R 3 When R has a substituent, 1 ~R 3 may be substituted with one substituent or with two or more substituents.

[0046] The definition of the monocyclic, linked or fused aromatic hydrocarbon group having 6 to 30 carbon atoms in (r-3) above is the same as the definition of the monocyclic, linked or fused aromatic hydrocarbon group having 6 to 30 carbon atoms described in (a-9) above, except for the definition of the substituent.

[0047] In addition, when the aromatic hydrocarbon group of (r-3) has a substituent, the substituent is preferably a deuterium atom, a fluorine atom, a linear or branched alkyl group having 1 to 18 carbon atoms, a linear or branched alkoxy group having 1 to 18 carbon atoms, a 9-carbazolyl group, a dibenzothienyl group, a dibenzofuranyl group, an N,N-diphenylamino group, or an N,N-bis(4-biphenylyl)-amino group.

[0048] Examples of the linear or branched alkyl group having 1 to 18 carbon atoms include the same linear alkyl groups having 1 to 18 carbon atoms as exemplified in (a-9) above. Examples of the linear or branched alkoxy group having 1 to 18 carbon atoms include the same linear or branched alkoxy groups having 1 to 18 carbon atoms as exemplified in the above-mentioned (a-9).

[0049] The definition of the monocyclic, linked or fused heteroaromatic group having 3 to 36 carbon atoms in the above (r-4) is the same as that of the monocyclic, linked or fused heteroaromatic group having 3 to 36 carbon atoms exemplified in the above (a-10), except for the definition of the substituent. A monocyclic, linked or fused heteroaromatic group having 3 to 20 carbon atoms is more preferable.

[0050] In addition, when the heteroaromatic group of (r-4) has a substituent, the substituent is preferably a deuterium atom, a fluorine atom, a linear or branched alkyl group having 1 to 18 carbon atoms, a linear or branched alkoxy group having 1 to 18 carbon atoms, a 9-carbazolyl group, a dibenzothienyl group, a dibenzofuranyl group, an N,N-diphenylamino group, or an N,N-bis(4-biphenylyl)-amino group. These substituents are, for example, defined in the same way as the substituent of (r-3) described above.

[0051] The definition of the linear or branched alkyl group having 1 to 18 carbon atoms in the above (r-5) is the same as that shown in the above (a-9).

[0052] In formulas (2) and (2'), L represents a phenylene group which may be substituted with a methyl group or a phenyl group; a naphthylene group which may be substituted with a methyl group or a phenyl group; a biphenylene group which may be substituted with a methyl group or a phenyl group; or a single bond.

[0053] Examples of the phenylene group include a 1,2-phenylene group, a 1,3-phenylene group, and a 1,4-phenylene group.

[0054] Examples of the naphthylene group include a naphthalene-1,2-diyl group, a naphthalene-1,4-diyl group, a naphthalene-1,8-diyl group, and a naphthalene-2,3-diyl group.

[0055] Examples of the biphenylene group include a biphenyl-4,4'-diyl group, a biphenyl-4,3'-diyl group, a biphenyl-4,2'-diyl group, a biphenyl-3,3'-diyl group, a biphenyl-3,2'-diyl group, and a biphenyl-2,2'-diyl group.

[0056] In formulas (2) and (2'), n represents an integer of 1 or 2. When L is a single bond, n is an integer of 1. When L is not a single bond, n is an integer of 1 or 2. Note that when n is 2, R 1 and R 2 There are two of each, and they may be the same or different.

[0057] <k1~k5について> k1 to k3 are each independently an integer of 0 to 4. k4 is an integer of 0 to 3. k5 is an integer of 0 to 1. When the sum of k1 to k5 (k1+k2+k3+k4+k5) is 2 or more, A 1 ~A 5 There are multiple A's, but there are multiple A's 1 ~A 5 may be the same as or different from each other.

[0058] The sum of k1 to k5 is preferably 3 or less, and more preferably 2 or less. When the sum of k1 to k5 is 3 or less, the molecular weight is smaller than that of a compound in which the sum of k1 to k5 is 4 or more. As a result, the sublimation temperature of the compound is lowered, and the heat resistance stability during sublimation is improved, which is preferable.

[0059] It is preferable that k1 to k3 are 0 or 1 from the viewpoint of realizing excellent charge transport in the organic EL device.

[0060] From the viewpoint of realizing excellent charge transport in an organic EL device, k4 is preferably 0 or 1, and more preferably 0.

[0061] From the viewpoint of realizing excellent charge transport in an organic EL device, k5 is preferably 0 or 1, and more preferably 0.

[0062] With regard to the fused ring compound represented by the above formula (1), one in which either or both of k1 and k2 are 1, and k3 to k5 are 0, is particularly preferred, from the viewpoint of realizing excellent charge transport in an organic EL device.

[0063] A 1 ~A 5 Preferred specific examples of the group include the groups (1) to (24) shown below. (1): Methyl group, ethyl group, fluorine atom, chlorine atom, bromine atom, iodine atom, cyano group, nitro group, hydroxyl group, thiol group, deuterium atom, methoxy group, trifluoromethylsulfonyloxy group

[0064] (2): phenyl group, 4-methylphenyl group, 3-methylphenyl group, 2-methylphenyl group, 2,4-dimethylphenyl group, 2,5-dimethylphenyl group, 3,4-dimethylphenyl group, 3,5-dimethylphenyl group, 2,6-dimethylphenyl group, 2,3,5-trimethylphenyl group, 2,3,6-trimethylphenyl group, 2,4,6-trimethylphenyl group, 3,4,5-trimethylphenyl group, 4-hydroxyphenyl group, 3-hydroxy group, 2-hydroxyphenyl group, 3,5-dihydroxyphenyl group, 3,4-dihydroxyphenyl group, 4-methoxyphenyl group, 3-methoxyphenyl group, 2-methoxyphenyl group, 3,5-dimethoxyphenyl group, 3,4-dimethoxyphenyl group, 4-trifluoromethylsulfonyloxyphenyl group, 3-trifluoromethylsulfonyloxyphenyl group, 2-trifluoromethylsulfonyloxyphenyl group, 3,5-bis(trifluoromethylsulfonyloxy)phenyl group, 3,4-bis(trifluoromethylsulfonyloxy)phenyl group,

[0065] (3): 4-biphenyl group, 3-biphenyl group, 2-biphenyl group, 2-methyl-1,1'-biphenyl-4-yl group, 3-methyl-1,1'-biphenyl-4-yl group, 2'-methyl-1,1'-biphenyl-4-yl group, 3'-methyl-1,1'-biphenyl-4-yl group, 4'-methyl-1,1'-biphenyl-4-yl group, 2,6-dimethyl-1,1'-biphenyl-4-yl group, 2,2'-dimethyl-1,1'-biphenyl-4-yl group, 2,3'-dimethyl dimethyl-1,1'-biphenyl-4-yl group, 2,4'-dimethyl-1,1'-biphenyl-4-yl group, 3,2'-dimethyl-1,1'-biphenyl-4-yl group, 2',3'-dimethyl-1,1'-biphenyl-4-yl group, 2',4'-dimethyl-1,1'-biphenyl-4-yl group, 2',5'-dimethyl-1,1'-biphenyl-4-yl group, 2',6'-dimethyl-1,1'-biphenyl-4-yl group, 4-phenylbiphenyl group, 2-phenylbiphenyl group

[0066] (4): 1-naphthyl group, 2-naphthyl group, 2-methylnaphthalen-1-yl group, 4-methylnaphthalen-1-yl group, 6-methylnaphthalen-2-yl group, 4-(1-naphthyl)phenyl group, 4-(2-naphthyl)phenyl group, 3-(1-naphthyl)phenyl group, 3-(2-naphthyl)phenyl group, 3-methyl-4-(1-naphthyl)phenyl group, 3-methyl-4-(2-naphthyl)phenyl group, 4-(2-methylnaphthalen-1-yl)phenyl group, 3-( 2-methylnaphthalen-1-yl)phenyl group, 4-phenylnaphthalen-1-yl group, 4-(2-methylphenyl)naphthalen-1-yl group, 4-(3-methylphenyl)naphthalen-1-yl group, 4-(4-methylphenyl)naphthalen-1-yl group, 6-phenylnaphthalen-2-yl group, 4-(2-methylphenyl)naphthalen-2-yl group, 4-(3-methylphenyl)naphthalen-2-yl group, 4-(4-methylphenyl)naphthalen-2-yl group

[0067] (5): 2-fluorenyl group, 9,9-dimethyl-2-fluorenyl group, 9,9'-spirobifluorenyl group, 9-phenanthryl group, 2-phenanthryl group, 11,11'-dimethylbenzo[a]fluoren-9-yl group, 11,11'-dimethylbenzo[a]fluoren-3-yl group, 11,11'-dimethylbenzo[b]fluoren-9-yl group, 11,11'-dimethylbenzo[b]fluoren-3-yl group, 11,11'-dimethylbenzo[c]fluoren-9-yl group, 11,11'-dimethylbenzo[c]fluoren-2-yl group, 3-fluoranthenyl group, 8-fluoranthenyl group

[0068] (6): 1-imidazolyl group, 2-phenyl-1-imidazolyl group, 2-phenyl-3,4-dimethyl-1-imidazolyl group, 2,3,4-triphenyl-1-imidazolyl group, 2-(2-naphthyl)-3,4-dimethyl-1-imidazolyl group, 2-(2-naphthyl)-3,4-diphenyl-1-imidazolyl group, 1-methyl-2-imidazolyl group, 1-ethyl-2-imidazolyl group , 1-phenyl-2-imidazolyl group, 1-methyl-4-phenyl-2-imidazolyl group, 1-methyl-4,5-dimethyl-2-imidazolyl group, 1-methyl-4,5-diphenyl-2-imidazolyl group, 1-phenyl-4,5-dimethyl-2-imidazolyl group, 1-phenyl-4,5-diphenyl-2-imidazolyl group, 1-phenyl-4,5-dibiphenylyl-2-imidazolyl group

[0069] (7): 1-methyl-3-pyrazolyl group, 1-phenyl-3-pyrazolyl group, 1-methyl-4-pyrazolyl group, 1-phenyl-4-pyrazolyl group, 1-methyl-5-pyrazolyl group, 1-phenyl-5-pyrazolyl group

[0070] (8): 2-thiazolyl group, 4-thiazolyl group, 5-thiazolyl group, 3-isothiazolyl group, 4-isothiazolyl group, 5-isothiazolyl group (9): 2-oxazolyl group, 4-oxazolyl group, 5-oxazolyl group, 3-isoxazolyl group, 4-isoxazolyl group, 5-isoxazolyl group

[0071] (10): 2-pyridyl group, 3-methyl-2-pyridyl group, 4-methyl-2-pyridyl group, 5-methyl-2-pyridyl group, 6-methyl-2-pyridyl group, 3-pyridyl group, 4-methyl-3-pyridyl group, 4-pyridyl group, 2-pyrimidyl group, 2,2'-bipyridin-3-yl group, 2,2'-bipyridin-4-yl group, 2,2'-bipyridin-5-yl group, 2,3'-bipyridin-3-yl group, 2,3'-bipyridin-4-yl group, 2,3'-bipyridin-5-yl group, 5-pyrimidyl group, pyrazyl group, 1,3,5-triazyl group, 4,6-diphenyl-1,3,5-triazin-2-yl group

[0072] (11): 1-benzimidazolyl group, 2-methyl-1-benzimidazolyl group, 2-phenyl-1-benzimidazolyl group, 1-methyl-2-benzimidazolyl group, 1-phenyl-2-benzimidazolyl group, 1-methyl-5-benzimidazolyl group, 1,2-dimethyl-5-benzimidazolyl group, 1-methyl-2-phenyl-5-benzimidazolyl group, 1-phenyl-5-benzimidazolyl group, 1,2-diphenyl-5-benzimidazolyl group, 1-methyl-6-benzimidazolyl group, 1,2-dimethyl-6-benzimidazolyl group, 1-methyl-2-phenyl-6-benzimidazolyl group, 1-phenyl-6-benzimidazolyl group, 1,2-diphenyl-6-benzimidazolyl group, 1-methyl-3-indazolyl group, 1-phenyl-3-indazolyl group

[0073] (12): 2-benzothiazolyl group, 4-benzothiazolyl group, 5-benzothiazolyl group, 6-benzothiazolyl group, 7-benzothiazolyl group, 3-benzoisothiazolyl group, 4-benzoisothiazolyl group, 5-benzoisothiazolyl group, 6-benzoisothiazolyl group, 7-benzoisothiazolyl group, 2,1,3-benzothiadiazol-4-yl group, 2,1,3-benzothiadiazol-5-yl group

[0074] (13): 2-benzoxazolyl group, 4-benzoxazolyl group, 5-benzoxazolyl group, 6-benzoxazolyl group, 7-benzoxazolyl group, 3-benzoisoxazolyl group, 4-benzoisoxazolyl group, 5-benzoisoxazolyl group, 6-benzoisoxazolyl group, 7-benzoisoxazolyl group, 2,1,3-benzoxadiazolyl-4-yl group, 2,1,3-benzoxadiazolyl-5-yl group

[0075] (14): 2-quinolyl group, 3-quinolyl group, 5-quinolyl group, 6-quinolyl group, 1-isoquinolyl group, 4-isoquinolyl group, 5-isoquinolyl group, 2-quinoxalyl group, 3-phenyl-2-quinoxalyl group, 6-quinoxalyl group, 2,3-dimethyl-6-quinoxalyl group, 2,3-diphenyl-6-quinoxalyl group, 2-quinazolyl group, 4-quinazolyl group, 2-acridinyl group, 9-acridinyl group, 1,10-phenanthroline-3-yl group, 1,10-phenanthroline-5-yl group

[0076] (15): 2-thienyl group, 3-thienyl group, 2-benzothienyl group, 3-benzothienyl group, 2-dibenzothienyl group, 4-dibenzothienyl group (16): 2-furanyl group, 3-furanyl group, 2-benzofuranyl group, 3-benzofuranyl group, 2-dibenzofuranyl group, 4-dibenzofuranyl group

[0077] (17): 9-methylcarbazol-2-yl group, 9-methylcarbazol-3-yl group, 9-methylcarbazol-4-yl group, 9-phenylcarbazol-2-yl group, 9-phenylcarbazol-3-yl group, 9-phenylcarbazol-4-yl group, 9-biphenylcarbazol-2-yl group, 9-biphenylcarbazol-3-yl group, 9-biphenylcarbazol-4-yl group

[0078] (18): 2-thianthryl group, 10-phenylphenothiazin-3-yl group, 10-phenylphenothiazin-2-yl group, 10-phenylphenoxazin-3-yl group, 10-phenylphenoxazin-2-yl group (19): 1-methylindol-2-yl group, 1-phenylindol-2-yl group, 9-phenylcarbazol-4-yl group

[0079] (20): 4-(2-pyridyl)phenyl group, 4-(3-pyridyl)phenyl group, 4-(4-pyridyl)phenyl group, 3-(2-pyridyl)phenyl group, 3-(3-pyridyl)phenyl group, 3-(4-pyridyl)phenyl group

[0080] (21): 4-(2-phenylimidazol-1-yl)phenyl group, 4-(1-phenylimidazol-2-yl)phenyl group, 4-(2,3,4-triphenylimidazol-1-yl)phenyl group, 4-(1-methyl-4,5-diphenylimidazol-2-yl)phenyl group, 4-(2-methylbenzimidazol-1-yl)phenyl group, 4-(2-phenylbenzimidazol-1-yl)phenyl group, 4-(1-methylbenzimidazol-2-yl)phenyl group, 4-(2-phenylbenzimidazol-1-yl)phenyl group, 3-(2-methylbenzimidazol-1-yl)phenyl group, 3-(2-phenylbenzimidazol-1-yl)phenyl group, 3-(1-methylbenzimidazol-2-yl)phenyl group, 3-(1-phenylbenzimidazol-1-yl)phenyl group

[0081] (22): 4-(3,5-diphenyltriazin-1-yl)phenyl group, 4-(2-thienyl)phenyl group, 4-(2-furanyl)phenyl group, 5-phenylthiophen-2-yl group, 5-phenylfuran-2-yl group, 4-(5-phenylthiophen-2-yl)phenyl group, 4-(5-phenylfuran-2-yl)phenyl group, 3-(5-phenylthiophen-2-yl)phenyl group, 3-(5-phenylfuran-2-yl)phenyl group, 4-(2-benzothienyl)phenyl group, 4-(3-benzothienyl)phenyl group, 3-(2-benzothienyl)phenyl group, 3-(3 -benzothienyl)phenyl group, 4-(2-dibenzothienyl)phenyl group, 4-(4-dibenzothienyl)phenyl group, 3-(2-dibenzothienyl)phenyl group, 3-(4-dibenzothienyl)phenyl group, 4-(2-dibenzofuranyl)phenyl group, 4-(4-dibenzofuranyl)phenyl group, 3-(2-dibenzofuranyl)phenyl group, 3-(4-dibenzofuranyl)phenyl group, 5-phenylpyridin-2-yl group, 4-phenylpyridin-2-yl group, 5-phenylpyridin-3-yl group, 4-(9-carbazolyl)phenyl group, 3-(9-carbazolyl)phenyl group

[0082] (23): 2-dibenzo[g,p]chrysenyl group, 3-dibenzo[g,p]chrysenyl group, 2-(7-phenyl)dibenzo[g,p]chrysenyl group, 3-(7-phenyl)dibenzo[g,p]chrysenyl group

[0083] (24): N,N-diphenylamino group, N,N-bis(4-biphenylyl)-amino group, N,N-bis(3-biphenylyl)-amino group, N-phenyl-4-biphenylamino group, N-phenyl-3-biphenylamino group, N-(4-biphenyl)-4-p-terphenylamino group, N-[4-(carbazol-9-yl)phenyl]-4-biphenylamino group, N 3 -[1,1'-biphenyl]-4-yl-N 1 ,N 1-Diphenyl-1,3-benzenediamino group, 4-triphenylamino group, 3-triphenylamino group, 4-(4',4''-diphenyl)triphenylamino group, 3-(4',4''-diphenyl)triphenylamino group, N 1 ,N 1 ,N 3 ,N 3 -Tetraphenyl-1,3-benzenediamino group, 4-(phenylamino)triphenylamino group

[0084] In the fused ring compound represented by formula (1), A 1 ~A 5 each independently represents, in terms of ease of availability of raw materials, a phenyl group, a biphenylyl group, a pyridylphenyl group, a terphenylyl group, a naphthyl group, a phenanthryl group, a pyrenyl group, a 9,9-spirobi[9H-fluorenyl] group, a triphenylenyl group, a dibenzothienyl group, a dibenzofuranyl group, a pyridyl group, a pyrimidyl group, or a group in which any of these groups is substituted with a cyano group, a nitro group, a hydroxyl group, a thiol group, a fluorine atom, a chlorine atom, a chlorine atom, a bromine atom, an iodine atom, a methyl group, a methoxy group, or a trifluoromethylsulfonyloxy group; a fluorenyl group, a benzofluorenyl group, an anthryl group, a dibenzo[g,p]chrysenyl group, a carbazolyl group, or any of these groups substituted with a cyano group, a nitro group, a hydroxyl group, a thiol group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a methyl group, a methoxy group, or a phenyl group; 4,6-diphenyl-1,3,5-triazin-2-yl group, (4,6-diphenyl-1,3,5-triazin-2-yl)phenyl group, 4,6-bis(4-biphenylyl)-1,3,5-triazin-2-yl group, 4,6-bis(3-biphenylyl)-1,3,5-triazin-2-yl group, cyano group, nitro group, hydroxyl group, thiol group, fluorine atom, chlorine atom, bromine atom, iodine atom, diphenylphosphine oxide, triphenylsilyl group, dihydroxyboryl group (-B(OH)2), 4,4,5,5-tetramethyl-[1,3,2]-dioxaborolane group, 5,5-dimethyl-[1,3,2]-dioxaborinane group, methyl group, N,N-diphenylamino group, N,N-bis(4-biphenylyl)amino group, N 3 -[1,1'-biphenyl]-4-yl-N 1 ,N 1 -Diphenyl-1,3-benzenediamino group, N-phenyl-3-biphenylylamino group, 4-triphenylamino group, 3-triphenylamino group, 4-(4',4''-diphenyl)triphenylamino group, 3-(4',4''-diphenyl)triphenylamino group, N 1 ,N 1 ,N 3 ,N 3 -tetraphenyl-1,3-benzenediamino group, or 4-(phenylamino)triphenylamino group.

[0085] <Preferred specific examples of dibenzoindenochrysene compounds> Preferred specific examples of the dibenzoindenochrysene compound represented by formula (1) are shown below, but the invention is not limited thereto.

[0086] Tables B-1 to B-7 show compounds (N-1) to (N-275) having substitution positions (1A) to (1F) shown in Table A-1, and the substituent A at the substitution position is a group shown in Tables B-1 to B-7. Here, N represents any symbol of 1A to 1F. Therefore, for example, in the case of a compound (1A-3), when N=1A, it shows a compound (1A-3) having a skeleton of (1A) and the substituent A of the skeleton is a Cl atom. (Table A-1)

[0087]

Table 1

[0088]

Table 2

[0089]

Table 3

[0090]

Table 4

[0091]

Table 5

[0092]

Table 6

[0093]

Table 7

[0094]

Table 8

[0095]

Table 9

[0096]

Table 10

[0097] [Table 11] (Table D-3)

[0098] [Table 12] (Table D-4)

[0099] [Table 13]

[0100] Hereinafter, applications of the dibenzoindenochrysene compound according to an embodiment of the present invention (hereinafter, also referred to as fused ring compound (1)) will be described.

[0101] <Materials for organic electroluminescence devices, electron transport materials for organic electroluminescence devices> The fused ring compound (1) can be used, for example, as a material for an organic electroluminescent device, although it is not particularly limited thereto. The fused ring compound (1) can also be used, for example, as an electron transport material for an organic electroluminescent device.

[0102] A material for organic electroluminescent elements according to one embodiment of the present invention contains a fused ring compound represented by the following formula (1'). Also, an electron transport material for organic electroluminescent elements according to one embodiment of the present invention contains the fused ring compound (1'). The material for organic electroluminescent elements and the electron transport material for organic electroluminescent elements containing the fused ring compound (1') contribute to the production of organic electroluminescent elements having excellent driving voltage characteristics and current efficiency.

[0103] [ka] In formula (1'), A 1 ~A 5 each independently represents a charge transport group; k1 to k3 each independently represent an integer of 0 or more and 4 or less; k4 is an integer between 0 and 3; k5 is an integer between 0 and 1; Multiple A's 1 ~A 5 may be the same or different. A in formula (1') 1 ~A 5 The definitions of k1 to k5 are the same as in formula (1), except that the sum of k1 to k5 is an integer of 0 or more. Therefore, the material for organic electroluminescent devices according to one embodiment of the present invention includes a fused ring compound in which the sum of k1 to k5 in formula (1') is 0, that is, an unsubstituted fused ring compound.

[0104] The fused ring compound (1') according to one embodiment of the present invention has a LUMO value of 1.8 to 2.6 eV, preferably 1.9 to 2.5 eV, and more preferably 2.0 to 2.4 eV. The LUMO value is a value obtained by measuring the reduction potential by cyclic voltammetry. The fused ring compound (1') is characterized in that the first reduction wave is reversible.

[0105] Furthermore, dibenzoindenochrysene, which is the basic skeleton of the fused ring compound (1') according to one embodiment of the present invention, is one-dimensionally stacked in single crystal X-ray structural analysis, with the stack distance being approximately 3.8 to 3.9 Å, and therefore has good orientation.

[0106] It is presumed that these structural characteristics contribute to the function of the material as an organic electroluminescent material, which will be described below.

[0107] <Organic electroluminescent device> The organic electroluminescent device according to one aspect of the present invention contains a fused ring compound (1'). The configuration of the organic electroluminescent device is not particularly limited, but examples thereof include the following configurations (i) to (vi).

[0108] (i): Anode / Emitting layer / Cathode (ii): anode / hole transport layer / light emitting layer / cathode (iii): anode / light-emitting layer / electron transport layer / cathode (iv): anode / hole transport layer / light emitting layer / electron transport layer / cathode (v): anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode (vi): Anode / hole injection layer / charge generation layer / hole transport layer / light emitting layer / electron transport layer / cathode

[0109] Hereinafter, an organic electroluminescence device according to an embodiment of the present invention will be described in more detail by taking the above-mentioned configuration (vi) as an example with reference to Fig. 1. Fig. 1 is a schematic cross-sectional view showing an example of a layered configuration of an organic electroluminescence device containing a cyclic azine compound according to an embodiment of the present invention.

[0110] 1 has a so-called bottom-emission type element configuration, the organic electroluminescent element according to one embodiment of the present invention is not limited to the bottom-emission type element configuration. That is, the organic electroluminescent element according to one embodiment of the present invention may have a top-emission type element configuration or another known element configuration.

[0111] The organic electroluminescent device 100 includes a substrate 1, an anode 2, a hole injection layer 3, a charge generation layer 4, a hole transport layer 5, a light emitting layer 6, an electron transport layer 7, and a cathode 8, in this order. However, some of these layers may be omitted, or other layers may be added. For example, an electron injection layer may be provided between the electron transport layer 7 and the cathode 8, or the charge generation layer 4 may be omitted, and the hole transport layer 5 may be provided directly on the hole injection layer 3.

[0112] Alternatively, a single layer having the functions of multiple layers, such as an electron injection / transport layer having both the functions of an electron injection layer and an electron transport layer, may be provided instead of the multiple layers. Furthermore, the single-layer hole transport layer 5 and the single-layer electron transport layer 7 may each be made up of multiple layers.

[0113] [Layer containing fused ring compound (1')] The organic electroluminescent device contains the fused ring compound represented by the above formula (1') in one or more layers selected from the group consisting of the light-emitting layer and the layer between the light-emitting layer and the cathode. Thus, in the configuration example shown in Fig. 1, the organic electroluminescent device 100 contains the fused ring compound (1') in at least one layer selected from the group consisting of the light-emitting layer 6 and the electron transport layer 7. In particular, it is preferable that the electron transport layer 7 contains the fused ring compound (1').

[0114] The fused ring compound (1') may be contained in a plurality of layers of the organic electroluminescent device. When an electron injection layer is provided between the electron transport layer and the cathode, the electron injection layer may contain the fused ring compound (1').

[0115] Hereinafter, the organic electroluminescent device 100 in which the electron transport layer 7 contains the fused ring compound (1') will be described.

[0116] [Substrate 1] There is no particular limitation on the substrate, and examples thereof include a glass plate, a quartz plate, a plastic plate, etc. In addition, in the case of a configuration in which light emission is extracted from the substrate 1 side, the substrate 1 is transparent to the wavelength of light.

[0117] Examples of light-transmitting plastic films include films made of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC), cellulose triacetate (TAC), cellulose acetate propionate (CAP), and the like.

[0118] [Anode 2] An anode 2 is provided on the substrate 1 (on the hole injection layer 3 side). In the case of an organic electroluminescent device in which light is emitted through the anode, the anode is formed from a material that is transparent or substantially transparent to the emitted light.

[0119] The transparent material used for the anode is not particularly limited, but examples thereof include indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide, aluminum-doped tin oxide, magnesium indium oxide, nickel tungsten oxide, other metal oxides, metal nitrides such as gallium nitride, metal selenides such as zinc selenide, and metal sulfides such as zinc sulfide.

[0120] In the case of an organic electroluminescent device in which light is extracted only from the cathode side, the transmittance characteristics of the anode are not important. Therefore, examples of materials that can be used for the anode in this case include gold, iridium, molybdenum, palladium, platinum, etc. A buffer layer (electrode interface layer) may be provided on the anode.

[0121] [Hole injection layer 3, hole transport layer 5] Between the anode 2 and a light-emitting layer 6 described later, a hole injection layer 3, a charge generation layer 4 described later, and a hole transport layer 5 are provided in this order from the anode 2 side.

[0122] The hole injection layer and the hole transport layer have the function of transporting holes injected from the anode to the light-emitting layer. By interposing this hole injection layer and hole transport layer between the anode and the light-emitting layer, a large number of holes can be injected into the light-emitting layer with a lower electric field.

[0123] The hole injection layer and the hole transport layer also function as electron barrier layers. That is, the electrons injected from the cathode and transported from the electron injection layer and / or the electron transport layer to the light emitting layer are prevented from leaking to the hole injection layer and / or the hole transport layer due to the electron barrier present at the interface between the light emitting layer and the hole injection layer and / or the hole transport layer. As a result, the electrons are accumulated at the interface in the light emitting layer, which brings about effects such as improved current efficiency, and an organic electroluminescent device with excellent light emitting performance is obtained.

[0124] The material for the hole injection layer and the hole transport layer has at least one of hole injection property, hole transport property, and electron barrier property. The material for the hole injection layer and the hole transport layer may be either an organic material or an inorganic material.

[0125] Specific examples of materials for the hole injection layer and the hole transport layer include triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline-based copolymers, conductive polymer oligomers (particularly thiophene oligomers), porphyrin compounds, aromatic tertiary amine compounds, styrylamine compounds, etc. Among these, porphyrin compounds, aromatic tertiary amine compounds, and styrylamine compounds are preferred, and aromatic tertiary amine compounds are particularly preferred.

[0126] Specific examples of aromatic tertiary amine compounds and styrylamine compounds include N,N,N',N'-tetraphenyl-4,4'-diaminophenyl, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-[1,1'-biphenyl]-4,4'-diamine (TPD), 2,2-bis(4-di-p-tolylaminophenyl)propane, 1,1-bis(4-di-p-tolylaminophenyl)cyclohexane, N,N,N',N'-tetra-p-tolyl-4,4'-diaminobiphenyl, 1,1-bis(4-di-p-tolylaminophenyl)-4-phenylcyclohexane, bis(4-dimethylamino-2-methylphenyl)phenylmethane, bis(4-di-p-tolylaminophenyl)phenylmethane, N,N'-diphenyl-N,N'- Examples of such compounds include di(4-methoxyphenyl)-4,4'-diaminobiphenyl, N,N,N',N'-tetraphenyl-4,4'-diaminodiphenyl ether, 4,4'-bis(diphenylamino)quadriphenyl, N,N,N-tri(p-tolyl)amine, 4-(di-p-tolylamino)-4'-[4-(di-p-tolylamino)styryl]stilbene, 4-N,N-diphenylamino-(2-diphenylvinyl)benzene, 3-methoxy-4'-N,N-diphenylaminostilbene, N-phenylcarbazole, 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPD), and 4,4',4''-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (MTDATA). Furthermore, inorganic compounds such as p-type Si and p-type SiC can also be given as examples of materials for the hole injection layer and the hole transport layer.

[0127] The hole injection layer and the hole transport layer may have a single layer structure made of one or more materials, or may have a laminate structure made of multiple layers of the same or different compositions.

[0128] [Charge generation layer 4] Between the hole injection layer 3 and the hole transport layer 5, a charge generation layer 4 may be provided. The material for the charge generating layer is not particularly limited, but may be, for example, dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN). The charge generating layer may have a single layer structure made of one or more materials, or may have a laminate structure made of multiple layers of the same or different compositions.

[0129] [Light-emitting layer 6] The light-emitting layer 6 is provided between the hole transport layer 5 and the electron transport layer 7 described below. Examples of materials for the light-emitting layer include phosphorescent materials, fluorescent materials, and thermally activated delayed fluorescent materials. In the light-emitting layer, electron-hole pairs are recombined, resulting in light emission.

[0130] The light-emitting layer may consist of a single small molecule or single polymeric material, but more commonly consists of a host material doped with a guest compound. Emission comes primarily from the dopant and can be of any color.

[0131] Examples of the host material include compounds having a biphenyl group, a fluorenyl group, a triphenylsilyl group, a carbazole group, a pyrenyl group, and an anthryl group. More specifically, examples of the compound include DPVBi (4,4'-bis(2,2-diphenylvinyl)-1,1'-biphenyl), BCzVBi (4,4'-bis(9-ethyl-3-carbazovinylene)-1,1'-biphenyl), TBADN (2-tertiarybutyl-9,10-di(2-naphthyl)anthracene), ADN (9,10-di(2-naphthyl)anthracene), CBP (4,4'-bis(carbazol-9-yl)biphenyl), CDBP (4,4'-bis(carbazol-9-yl)-2,2'-dimethylbiphenyl), 2-(9-phenylcarbazol-3-yl)-9-[4-(4-phenylphenylquinazolin-2-yl)carbazole, 9,10-bis(biphenyl)anthracene, and the like.

[0132] Examples of the fluorescent dopant include anthracene, pyrene, tetracene, xanthene, perylene, rubrene, coumarin, rhodamine, quinacridone, dicyanomethylenepyran compound, thiopyran compound, polymethine compound, pyrylium, thiapyrylium compound, fluorene derivative, periflanthene derivative, indenoperylene derivative, bis(azinyl)amine boron compound, bis(azinyl)methane compound, carbostyril compound, etc. The fluorescent dopant may be a combination of two or more selected from these.

[0133] Phosphorescent dopants include, for example, organometallic complexes of transition metals such as iridium, platinum, palladium, and osmium.

[0134] Specific examples of fluorescent dopants and phosphorescent dopants include Alq3 (tris(8-hydroxyquinoline)aluminum), DPAVBi (4,4'-bis[4-(di-p-tolylamino)styryl]biphenyl), perylene, bis[2-(4-n-hexylphenyl)quinoline](acetylacetonate)iridium(III), Ir(PPy)3 (tris(2-phenylpyridine)iridium(III)), and FIrPic (bis(3,5-difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl)iridium(III))).

[0135] In addition, the light-emitting material is not limited to being contained only in the light-emitting layer. For example, the light-emitting material may be contained in a layer adjacent to the light-emitting layer (hole transport layer 5 or electron transport layer 7). This can further increase the current efficiency of the organic electroluminescent device.

[0136] The light-emitting layer may have a single layer structure made of one or more materials, or may have a laminate structure made of multiple layers of the same composition or different compositions.

[0137] [Electron transport layer 7] An electron transport layer 7 is provided between the light emitting layer 6 and a cathode 8 which will be described later. The electron transport layer has a function of transporting electrons injected from the cathode to the light-emitting layer. By interposing the electron transport layer between the cathode and the light-emitting layer, electrons are injected into the light-emitting layer at a lower electric field. As described above, the electron transport layer preferably contains a fused ring compound represented by the above formula (1').

[0138] The electron transport layer may further contain a conventionally known electron transport material in addition to the fused ring compound (1'). Examples of conventionally known electron transport materials include 8-hydroxyquinolinato lithium (Liq), bis(8-hydroxyquinolinato) zinc, bis(8-hydroxyquinolinato) copper, bis(8-hydroxyquinolinato) manganese, tris(8-hydroxyquinolinato) aluminum, tris(2-methyl-8-hydroxyquinolinato) aluminum, tris(8-hydroxyquinolinato) gallium, bis(10-hydroxybenzo[h]quinolinato) beryllium, bis(10-hydroxybenzo[h]quinolinato) zinc, bis(2-methyl-8-quinolinato) chlorogallium, bis(2-methyl-8-quinolinato) (o-cresolate) gallium, bis(2-methyl-8-quinolinato)-1-naphthol. bis(2-methyl-8-quinolinato)-2-naphtholatogallium, 2-[3-(9-phenanthrenyl)-5-(3-pyridinyl)phenyl]-4,6-diphenyl-1,3,5-triazine, and 2-(4,''-di-2-pyridinyl[1,1':3',1''-terphenyl]-5-yl)-4,6-diphenyl-1,3,5-triazine, BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), Bphen (4,7-diphenyl-1,10-phenanthroline), BAlq (bis(2-methyl-8-quinolinato)-4-(phenylphenolato)aluminum), and bis(10-hydroxybenzo[h]quinolinato)beryllium).

[0139] The electron transport layer may have a single layer structure made of one or more materials, or may have a laminate structure made of multiple layers of the same or different compositions. When the electron transport layer has a two-layer structure with a first electron transport layer on the light-emitting layer side and a second electron transport layer on the cathode side, it is preferable that the second electron transport layer contains a fused ring compound (1').

[0140] [Cathode 8] A cathode 8 is provided on the electron transport layer 7. In the case of an organic electroluminescent device configured so that only light emitted through the anode is extracted, the cathode can be made of any conductive material.

[0141] Examples of the material for the cathode include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al2O3) mixture, indium, lithium / aluminum mixture, rare earth metal, etc. A buffer layer (electrode interface layer) may be provided on the cathode (electron transport layer side).

[0142] [How each layer is formed] Each layer except for the electrodes (anode, cathode) described above can be formed by forming the material of each layer (together with a material such as a binder resin and a solvent, if necessary) into a thin film by a known method such as a vacuum deposition method, a spin coating method, a casting method, or a Langmuir-Blodgett method (LB method). There are no particular limitations on the film thickness of each layer thus formed, and it can be appropriately selected depending on the situation, but it is usually in the range of 5 nm to 5 μm.

[0143] The anode and cathode can be formed by forming a thin film of an electrode material by a method such as vapor deposition, sputtering, etc. A pattern may be formed through a mask having a desired shape during vapor deposition or sputtering, or a pattern having a desired shape may be formed by photolithography after forming a thin film by vapor deposition, sputtering, etc.

[0144] The film thickness of the anode and cathode is preferably 1 μm or less, and more preferably 10 nm or more and 200 nm or less.

[0145] The organic electroluminescent device according to one embodiment of the present invention may be used as a kind of lamp for illumination or exposure light source, or may be used as a projection device for projecting images, or a display device (display) for directly viewing still images or moving images.

[0146] When used as a display device for playing moving images, the driving method may be either a passive matrix method or an active matrix method. In addition, by using two or more kinds of organic electroluminescent devices of this embodiment having different emission colors, it is possible to prepare a full-color display device.

[0147] The fused ring compound (1) or (1′) according to one embodiment of the present invention can be synthesized by a known reaction (e.g., Non-Patent Document 1). However, from the viewpoint of yield, it is preferable to synthesize the compound via an intramolecular cyclization reaction of a compound represented by the following formula (3).

[0148] That is, a method for producing a fused ring compound according to one embodiment of the present invention includes a method of cyclizing a compound represented by formula (3) in the presence of a Lewis acid.

[0149] [ka] In formula (3), A 1 ~A 5 each independently represents a charge transport group; k1 to k3 each independently represent an integer of 0 or more and 4 or less; k4 is an integer between 0 and 3; k5 is an integer between 0 and 1; Multiple A's 1 ~A 5 may be the same or different; T represents the following formula (4) or (4');

[0150] [ka] In formulas (4) and (4'), R 1 ~R 9 represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms. A in Equation (3) 1 ~A 5 , k1 to k5 are defined the same as in formula (1). R in Equation (4) 1 ~R 9 The definition of R in formulas (2) and (2') is 1 ~R 3 is the same as:

[0151] <Reaction of the compound represented by formula (3)> The compound represented by formula (3) is reacted in the presence of a Lewis acid to obtain a fused ring compound represented by formula (1) or (1'). The raw material compound represented by formula (3) can be synthesized based on a known method, or a commercially available compound can be used.

[0152] The Lewis acid is not particularly limited, but from the viewpoint of yield, boron tribromide (BBr3), boron trichloride (BCl3), boron trifluoride diethyl ether complex (BF3·OEt2), aluminum chloride (AlCl3), trimethyliodosilane, iron (III) bromide (FeBr3), iron (III) chloride (FeCl3), antimony (V) chloride (SbCl5), titanium tetrachloride (TiCl4), zinc (II) bromide (ZnBr2), and zinc (II) chloride (ZnCl2) are listed. Among them, from the viewpoint of yield, boron trifluoride diethyl ether complex (BF3·OEt2), aluminum chloride (AlCl3), trimethyliodosilane, iron (III) bromide (FeBr3), and iron (III) chloride (FeCl3) are preferred, and boron trifluoride diethyl ether complex (BF3·OEt2) is more preferred.

[0153] Examples of the solvent include tetrahydrofuran, toluene, dimethylsulfoxide, dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, dichloromethane, chloroform, and chlorobenzene. Among these, from the viewpoint of yield, dichloromethane, chloroform, or chlorobenzene is preferred, and dichloromethane is more preferred.

[0154] From the viewpoint of yield, the reaction temperature is preferably from −20° C. to 100° C., more preferably from 0° C. to 80° C., and particularly preferably from 0° C. to 30° C. The reaction atmosphere is preferably a dry nitrogen or dry argon atmosphere, from the viewpoint of suppressing decomposition of the Lewis acid. EXAMPLES

[0155] The present invention will be described in more detail below based on examples, but the present invention should not be construed as being limited to these examples in any way.

[0156] 1 H-NMR measurements were performed using Gemini200 (Varian). The glass transition temperature was measured using a DSC7020 (manufactured by Hitachi High-Tech Science Corporation). The light-emitting characteristics of the organic electroluminescent device were evaluated by applying a direct current to the fabricated device at room temperature using a luminance meter (product name: BM-9, manufactured by Topcon Technohouse Corporation).

[0157] Synthesis Example 1: Synthesis of compound (1-73)

[0158] [ka] Under a nitrogen stream, 3-(2-bromo-4-chlorophenyl)fluoranthene (3.52 g, 9.0 mmol), 4-chloro[2-(pyrrolidin-1-yldiazenyl)phenyl]boronic acid (2.77 g, 10.8 mmol), dichloro(1,1'-bis(diphenylphosphino)ferrocene)palladium (148 mg, 0.20 mmol), tetrahydrofuran (9 mL), and 4M aqueous sodium hydroxide solution (4 mL) were added to a 50 mL two-neck flask, and the mixture was stirred at 70°C for 2 days. After cooling to room temperature, the aqueous layer and the organic layer were separated, and the organic layer was dried over anhydrous sodium sulfate, concentrated under reduced pressure, and reprecipitated (toluene / hexane) to obtain 2.0 g of a yellow powder containing 3-{4-chloro-2-[3-chloro-6-(pyrrolidin-1-yldiazenyl)phenyl]phenyl}fluoranthene. The obtained powder was used as it was in the next step.

[0159] Example 1 Synthesis of compound (1d-2)

[0160] [ka] In a 20mL two-neck flask, the powder (2.0g) obtained in Synthesis Example 1, BF3·OEt2 (0.70g, 5.0mmol), and dichloromethane (4mL) were added under a nitrogen stream and stirred at room temperature for 30 minutes. After adding pure water (4mL), the precipitated solid was collected by filtration. The obtained solid was recrystallized (toluene) to obtain 0.50g (1.19mmol) of compound (1d-2) (HPLC purity 99.6%). Compound identification 1 This was measured by H-NMR. 1 H-NMR(CDCl3)δ(ppm):9.07(s,1H),8.90(d,1H),8.78(d,1H),8.71(d,1H),8.62(dd ,2H),8.10(dd,1H),8.05-7.97(m,2H),7.82(t,1H),7.75-7.70(m,2H),7.47(dd,2H)

[0161] Example 2 Synthesis of compound (1d-27)

[0162] [ka] Compound (1d-2) (0.56 g, 1.33 mmol), phenylboronic acid (0.36 g, 2.93 mmol), palladium acetate (6.1 mg, 0.027 mmol), Xphos 25.8 mg (0.053 mmol), tetrahydrofuran (15 mL), and 2 M potassium carbonate aqueous solution (5 mL) were added to a 20 mL two-neck flask under a nitrogen stream, and the mixture was stirred at 70 °C for 6 hours. After cooling to room temperature, the aqueous layer and the organic layer were separated, and the obtained organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The concentrate was recrystallized (toluene) to obtain 0.50 g (0.99 mmol) of compound (1d-27) (yield 74.4%, HPLC purity 99.9%). Compound identification 1 This was measured by H-NMR. 1 H-NMR(CDCl3)δ(ppm):9.23(s,1H),9.08(d,1H),9.03(dd,2H),8.96(d,1H),8.89(d,1H) ,8.17-8.15(m,1H),8.07-8.00(m,4H),7.89-7.83(m,5H),7.58(t,4H),7.49-7.44(m,4H)

[0163] Next, the obtained compound was used to carry out element evaluation.

[0164] Element Example 1 (see Figure 2) (Preparation of substrate 101 and anode 102) A glass substrate with an indium-tin oxide (ITO) transparent electrode, on which a 2 mm wide ITO film (thickness 110 nm) was patterned in stripes, was prepared as a substrate with an anode on its surface. The substrate was then washed with isopropyl alcohol and then subjected to surface treatment with ozone ultraviolet cleaning.

[0165] (Preparation for vacuum deposition) After cleaning and surface treatment, each layer was deposited by vacuum deposition on the substrate by vacuum deposition, so that each layer was laminated. First, the glass substrate was placed in a vacuum deposition chamber and 1.0×10 -4 The pressure was reduced to 10 Pa. Then, each layer was formed according to the film formation conditions in the following order.

[0166] (Fabrication of Hole Injection Layer 103) Sublimation purified N-[1,1'-biphenyl]-4-yl-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9H-fluoren-2-amine and 1,2,3-tris[(4-cyano-2,3,5,6-tetrafluorophenyl)methylene]cyclopropane were deposited at a rate of 0.15 nm / sec to form a 10 nm film, forming a hole injection layer 103.

[0167] (Preparation of the first hole transport layer 1051) Sublimation purified N-[1,1′-biphenyl]-4-yl-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9H-fluoren-2-amine was formed into a film of 85 nm at a rate of 0.15 nm / sec to prepare a first hole transport layer 1051 .

[0168] (Preparation of second hole transport layer 1052) Sublimation-purified N-phenyl-N-(9,9-diphenylfluoren-2-yl)-N-(1,1′-biphenyl-4-yl)amine was formed into a film of 5 nm at a rate of 0.15 nm / sec to prepare a second hole transport layer 1052 .

[0169] (Fabrication of the Light-Emitting Layer 106) Sublimation-purified 3-(10-phenyl-9-anthryl)-dibenzofuran and 2,7-bis[N,N-di-(4-tertbutylphenyl)]amino-bisbenzofurano-9,9'-spirofluorene were mixed in a ratio of 95:5 (mass ratio) to form a 20 nm film, producing the light-emitting layer 106. The film formation rate was 0.18 nm / sec.

[0170] (Preparation of First Electron Transport Layer 1071) Sublimation-purified 2-[3′-(9,9-dimethyl-9H-fluoren-2-yl)[1,1′-biphenyl]-3-yl]-4,6-diphenyl-1,3,5-triazine was formed into a film of 6 nm at a speed of 0.05 nm / sec to prepare a first electron transport layer 1071 .

[0171] (Preparation of second electron transport layer 1072) Benz[g]indeno[1,2,3-qr]chrysene (hereinafter referred to as compound 1-0) synthesized according to Non-Patent Document 1 and Liq were mixed in a ratio of 50:50 (mass ratio) to form a 25 nm film, thereby producing a second electron transport layer 1072. The film formation rate was 0.15 nm / sec.

[0172] (Preparation of cathode 108) Finally, a metal mask was placed perpendicular to the ITO stripes on the substrate, and the cathode 108 was formed. The cathode had a two-layer structure, with silver / magnesium (mass ratio 1 / 10) and silver being formed in that order to thicknesses of 80 nm and 20 nm, respectively. The silver / magnesium film formation rate was 0.5 nm / sec, and the silver film formation rate was 0.2 nm / sec.

[0173] As a result, the light-emitting area of ​​4 mm2 shown in Figure 2 2 An organic electroluminescence device 100 was produced. The film thickness of each layer was measured using a stylus film thickness measuring instrument (DEKTAK, manufactured by Bruker).

[0174] Furthermore, this element was sealed in a nitrogen atmosphere glove box with oxygen and moisture concentrations of 1 ppm or less by sealing a glass sealing cap and the film-formed substrate (element) with bisphenol F type epoxy resin (manufactured by Nagase ChemteX Corporation).

[0175] A direct current was applied to the organic electroluminescent device fabricated as described above, and the light-emitting characteristics were evaluated using a luminance meter (product name: BM-9, manufactured by Topcon Technohouse). 2 The current efficiency (cd / A) was measured when current was passed through the device, and the device life (h) during continuous lighting was measured. The device life (h) was measured when the device was set to an initial luminance of 1000 cd / m2 The luminance decay time was measured when the device was continuously lit when driven at 1000 Hz, and the luminance (cd / m 2 The time required for the temperature to decrease by 5% was measured.

[0176] The voltage, current efficiency, and element life are relative values ​​with the result of element comparative example 1 set as the reference value (100). The obtained measurement results are shown in Table 1.

[0177] Element Example 2, Element Comparative Example 1, Element Comparative Example 2 Organic EL devices were prepared in the same manner as in Device Example 1, except that compound (1d-27), compound (X1), and compound (X2) were used in place of compound (1-0) in Device Example 1, and evaluated. The measurement results are shown in Table 1.

[0178] [ka]

[0179] [Table 14]

[0180] The fused ring compound (1) according to one embodiment of the present invention can be suitably used not only in conventional fluorescent devices but also in phosphorescent devices and organic electroluminescent devices utilizing thermally activated delayed fluorescence (TADF).

[0181] 1, 101 board 2, 102 anode 3, 103 Hole injection layer 4. Charge generation layer 5, 105 Hole transport layer 1051 First hole transport layer 1052 Second hole transport layer 6, 106 Light-emitting layer 7, 107 Electron transport layer 1071 First electron transport layer 1072 Second electron transport layer 8, 108 cathode 100 Organic electroluminescent device

Claims

1. A fused ring compound represented by formula (1): 【Chemistry 1】 (In formula (1), A １ ~A ５ each independently represents a charge transport group; k1 to k3 each independently represent an integer of 0 to 4; k4 is an integer of 0 to 3; k5 is an integer equal to or greater than 0 and equal to or less than 1; The sum of k1 to k5 is an integer of 1 or more; Multiple A's １ ~A ５ may be the same or different; the charge transporting groups each independently represent an aromatic hydrocarbon group having 6 to 30 carbon atoms and which is a monocyclic, linked or condensed ring, and which may have a substituent; The substituent is fluorine atom, Chlorine atom, Bromine atom, Iodine atom, Cyano group, Nitro group, Hydroxyl groups, Thiol groups, a phosphine oxide group which may have a monocyclic, linked or fused aromatic hydrocarbon group having 6 to 18 carbon atoms, or a fused heteroaromatic group; a silyl group which may have a monocyclic, linked or fused ring aromatic hydrocarbon group having 6 to 18 carbon atoms, or a fused ring heteroaromatic group; a boronyl group which may have a saturated hydrocarbon group having 2 to 10 carbon atoms, A linear or branched alkyl group having 1 to 18 carbon atoms, a linear or branched alkoxy group having 1 to 18 carbon atoms, or It is a trifluoromethylsulfonyloxy group.

2. The fused ring compound according to claim 1, wherein the sum of k1 to k5 is 1 or more and 3 or less.

3. The fused ring compound according to claim 1, wherein the sum of k1 to k5 is 1 or more and 2 or less.

4. The fused ring compound according to any one of claims 1 to 3, having a LUMO value of 1.8 to 2.6 eV.

5. A charge transport material for an organic electroluminescent device, comprising a fused ring compound represented by formula (1'): 【Chemistry 3】 (In formula (1'), A １ ~A ５ each independently represents a charge transport group; k1 to k3 each independently represent an integer of 0 to 4; k4 is an integer of 0 to 3; k5 is an integer equal to or greater than 0 and equal to or less than 1; Multiple A's １ ~A ５ may be the same or different; the charge transporting groups each independently represent an aromatic hydrocarbon group having 6 to 30 carbon atoms and which is a monocyclic, linked or condensed ring, and which may have a substituent; The substituent is fluorine atom, Chlorine atom, Bromine atom, Iodine atom, Cyano group, Nitro group, Hydroxyl groups, Thiol groups, a phosphine oxide group which may have a monocyclic, linked or fused aromatic hydrocarbon group having 6 to 18 carbon atoms, or a fused heteroaromatic group; a silyl group which may have a monocyclic, linked or fused ring aromatic hydrocarbon group having 6 to 18 carbon atoms, or a fused ring heteroaromatic group; a boronyl group which may have a saturated hydrocarbon group having 2 to 10 carbon atoms, A linear or branched alkyl group having 1 to 18 carbon atoms, a linear or branched alkoxy group having 1 to 18 carbon atoms, or It is a trifluoromethylsulfonyloxy group.

6. An electron transport material for an organic electroluminescent device, comprising the fused ring compound according to claim 5 .

7. An organic electroluminescent device comprising the fused ring compound according to claim 5 .

8. A method for producing a fused ring compound represented by formula (1), comprising the steps of: A method of intramolecularly cyclizing a compound represented by formula (3). 【Chemistry 1】 (In formula (1), A １ ~A ５ each independently represents a charge transport group; k1 to k3 each independently represent an integer of 0 to 4; k4 is an integer of 0 to 3; k5 is an integer equal to or greater than 0 and equal to or less than 1; The sum of k1 to k5 is an integer of 1 or more; Multiple A's １ ~A ５ may be the same or different; the charge transporting groups each independently represent an aromatic hydrocarbon group having 6 to 30 carbon atoms and which is a monocyclic, linked or condensed ring, and which may have a substituent; The substituent is fluorine atom, Chlorine atom, Bromine atom, Iodine atom, Cyano group, Nitro group, Hydroxyl groups, Thiol groups, a phosphine oxide group which may have a monocyclic, linked or fused aromatic hydrocarbon group having 6 to 18 carbon atoms, or a fused heteroaromatic group; a silyl group which may have a monocyclic, linked or fused ring aromatic hydrocarbon group having 6 to 18 carbon atoms, or a fused ring heteroaromatic group; a boronyl group which may have a saturated hydrocarbon group having 2 to 10 carbon atoms, A linear or branched alkyl group having 1 to 18 carbon atoms, a linear or branched alkoxy group having 1 to 18 carbon atoms, or It is a trifluoromethylsulfonyloxy group. 【Chemistry 4】 (In formula (3), A １ ~A ５ each independently represents a charge transport group; k1 to k3 each independently represent an integer of 0 to 4; k4 is an integer of 0 to 3; k5 is an integer equal to or greater than 0 and equal to or less than 1; The sum of k1 to k5 is an integer of 1 or more; Multiple A's １ ~A ５ may be the same or different; the charge transporting groups each independently represent an aromatic hydrocarbon group having 6 to 30 carbon atoms and which is a monocyclic, linked or condensed ring, and which may have a substituent; The substituent is fluorine atom, Chlorine atom, Bromine atom, Iodine atom, Cyano group, Nitro group, Hydroxyl groups, Thiol groups, a phosphine oxide group which may have a monocyclic, linked or fused aromatic hydrocarbon group having 6 to 18 carbon atoms, or a fused heteroaromatic group; a silyl group which may have a monocyclic, linked or fused ring aromatic hydrocarbon group having 6 to 18 carbon atoms, or a fused ring heteroaromatic group; a boronyl group which may have a saturated hydrocarbon group having 2 to 10 carbon atoms, A linear or branched alkyl group having 1 to 18 carbon atoms, a linear or branched alkoxy group having 1 to 18 carbon atoms, or a trifluoromethylsulfonyloxy group; T represents the following formula (4) or (4′): 【Chemistry 5】 In formulas (4) and (4′), R １ ~R ９ represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms.

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