JP7656288B2 - Fused ring compound, its production method, and material for organic electroluminescent device - Google Patents

Description

The present invention relates to a fused ring compound, a method for producing the same, and a material for an organic electroluminescent device that contains the same.

Organic electroluminescent devices are used not only for small displays but also for large televisions, lighting, and other applications, and their development is being actively pursued.

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 is being explored and examined. As a polycyclic compound, Non-Patent Document 1 does not report any findings on organic electroluminescence, but does disclose benz[g]indeno[1,2,3-qr]chrysene.

Angewandte Chemie, International Edition, 2017, 56, p. 12224-12228.

The purpose of one aspect of the present invention is to propose a compound having a new mother nucleus, while continuing to explore and examine the possibility of various polycyclic compounds as the mother nucleus of new materials.

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.

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

In formula (1),
A ¹ to A ⁵ each independently represent a charge transporting 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;
A ¹ to A ⁵ may be the same or different.

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

式（１’）中、
Ａ^１～Ａ^５は、それぞれ独立して、電荷輸送性基を表し；
ｋ１～ｋ３は、それぞれ独立して、０以上４以下の整数であり；
ｋ４は０以上３以下の整数であり；
ｋ５は０以上１以下の整数であり；
複数のＡ^１～Ａ^５は、同一であっても異なっていてもよい。

In formula (1'),
A ¹ to A ⁵ each independently represent a charge transporting 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;
A ¹ to A ⁵ may be the same or different.

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 the fused ring compound represented by the above formula (1').

According to one aspect of the present invention, it is possible to provide a fused ring 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 excellent driving voltage.

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).

式（３）中、
Ａ^１～Ａ^５は、それぞれ独立して、電荷輸送性基を表し；
ｋ１～ｋ３は、それぞれ独立して、０以上４以下の整数であり；
ｋ４は０以上３以下の整数であり；
ｋ５は０以上１以下の整数であり；
ｋ１～ｋ５の合計は１以上の整数であり；
複数のＡ^１～Ａ^５は、同一であっても異なっていてもよく；
Ｔは下記の式（４）または（４’）を表す；

In formula (3),
A ¹ to A ⁵ each independently represent a charge transporting 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;
A ¹ to A ⁵ may be the same or different;
T represents the following formula (4) or (4′):

式（４）および（４’）中、
Ｒ^１～Ｒ^９は水素原子または炭素数１～１２のアルキル基を表す。

In formulas (4) and (4′),
R ¹ to R ⁹ each represent a hydrogen atom or an alkyl group having 1 to 12 carbon atoms.

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. 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 (Device Example 1).

The fused ring compound according to one embodiment of the present invention is described in detail below.

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

In formula (1),
A ¹ to A ⁵ each independently represent a charge transporting 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;
A ¹ to A ⁵ may be the same or different.

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

<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.

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) a 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'):

式中、
Ｒ^１～Ｒ^３は、それぞれ独立して、
（ｒ－１）水素原子、（ｒ－２）重水素原子、
（ｒ－３）置換基を有していてもよい炭素数６～３０の単環、連結、もしくは縮環の芳香族炭化水素基、
（ｒ－４）置換基を有していてもよい炭素数３～３６の単環、連結、もしくは縮環のヘテロ芳香族基、または、
（ｒ－５）炭素数１～１８の直鎖もしくは分岐のアルキル基を表し；
Ｌは、それぞれ独立して、
メチル基もしくはフェニル基で置換されていてもよいフェニレン基、
メチル基もしくはフェニル基で置換されていてもよいナフチレン基、
メチル基もしくはフェニル基で置換されていてもよいビフェニレン基、または、
単結合を表し；
ｎは、１または２を表し、
Ｌが単結合の場合、ｎは１であり、
Ｌが単結合ではない場合、ｎは１または２であり；
ｎが２の場合、複数のＲ^１～Ｒ^２は、同一であっても異なっていてもよい。

In the formula,
R ¹ to R ³ each independently represent
(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 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;
Each 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;
When n is 2, R ¹ to R ² may be the same or different.

<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. Furthermore, 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.

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.

Examples of the phosphine oxide group include an unsubstituted phosphine oxide group and a phosphine oxide group having a substituent. A phosphine oxide group having a substituent is preferable.

As the phosphine oxide group having a substituent, a phosphine oxide group having a monocyclic, linked, or fused aromatic hydrocarbon group having 6 to 18 carbon atoms, or a fused heteroaromatic group, is preferred. Specific examples include groups substituted with two aryl groups, such as diphenylphosphine oxide.

Examples of the silyl group include unsubstituted silyl groups and substituted silyl groups. Substituted silyl groups are preferred.

As the silyl group having a substituent, a silyl group having a monocyclic, linked, or fused aromatic hydrocarbon group having 6 to 18 carbon atoms, or a fused heteroaromatic group, is preferred. Specific examples include groups substituted with three aryl groups, such as a triphenylsilyl group.

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.

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

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

<Regarding (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.

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 the 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.

In addition, when the heteroaromatic group of (a-10) has a substituent, the substituent is preferably 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.

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

<Regarding (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.

<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).

<Regarding (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).

<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).

<Regarding (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).

<Regarding (a-17)>
(a-17) is a group represented by formula (2) or (2'), and as described above, the charge transporting group may be a group represented by the above formula (2) or (2'). In formula (2) and (2'), the definitions of L, R ¹ to R ³ and n are as follows:

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

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.

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.

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 (a-9) above.

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

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.

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

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.

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

Examples of the naphthylene group include naphthalene-1,2-diyl, naphthalene-1,4-diyl, naphthalene-1,8-diyl, and naphthalene-2,3-diyl groups.

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

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.
When n is 2, there are two R ^1s and two R ^2s , which may be the same or different.

<About k1 to k5>
Each of k1 to k3 is independently an integer of 0 or more and 4 or less. k4 is an integer of 0 or more and 3 or less. k5 is an integer of 0 or more and 1 or less. When the sum of k1 to k5 (k1+k2+k3+k4+k5) is 2 or more, a plurality of A ¹ to A ⁵ are present, and the plurality of A ¹ to A ⁵ may be the same as or different from each other.

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.

In order to achieve excellent charge transport in the organic EL element, k1 to k3 are preferably 0 or 1.

From the viewpoint of realizing excellent charge transport in the organic EL element, k4 is preferably 0 or 1, and more preferably 0.

From the viewpoint of realizing excellent charge transport in the organic EL element, k5 is preferably 0 or 1, and more preferably 0.

For the fused ring compound represented by the above formula (1), from the viewpoint of realizing excellent charge transport in an organic EL device, it is particularly preferable that either or both of k1 and k2 are 1, and k3 to k5 are 0.

Preferred examples of A ¹ to A ⁵ 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

(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,

(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 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

(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-methylnaphthalene-1-yl)phenyl group, 4-phenylnaphthalene-1-yl group, 4-(2-methylphenyl)naphthalene-1-yl group, 4-(3-methylphenyl)naphthalene-1-yl group, 4-(4-methylphenyl)naphthalene-1-yl group, 6-phenylnaphthalene-2-yl group, 4-(2-methylphenyl)naphthalene-2-yl group, 4-(3-methylphenyl)naphthalene-2-yl group, 4-(4-methylphenyl)naphthalene-2-yl group

(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

(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

(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

(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

(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

(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

(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

(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

(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

(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

(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

(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

(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

(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

(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

(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

(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

In the fused ring compound represented by formula (1), A ¹ to A ⁵ are each independently selected from the viewpoint 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 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 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 is preferred.

<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.

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 from 1A to 1F. Thus, 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 a substituent A of the skeleton that is a Cl atom.
(Table A-1)

（表Ｂ－１）

(Table B-1)

（表Ｂ－２）

(Table B-2)

（表Ｂ－３）

(Table B-3)

（表Ｂ－４）

(Table B-4)

（表Ｂ－５）

(Table B-5)

（表Ｂ－６）

(Table B-6)

（表Ｂ－７）

(Table B-7)

（表Ｃ－１）

(Table C-1)

（表Ｄ－１）

(Table D-1)

（表Ｄ－２）

(Table D-2)

（表Ｄ－３）

(Table D-3)

（表Ｄ－４）

(Table D-4)

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

<Material for organic electroluminescence device, electron transport material for organic electroluminescence device>
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.

The material for organic electroluminescent elements according to one embodiment of the present invention contains a fused ring compound represented by the following formula (1'). The electron transport material for organic electroluminescent elements according to one embodiment of the present invention contains a 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 with excellent driving voltage characteristics and current efficiency.

式（１’）中、
Ａ^１～Ａ^５は、それぞれ独立して、電荷輸送性基を表し；
ｋ１～ｋ３は、それぞれ独立して、０以上４以下の整数であり；
ｋ４は０以上３以下の整数であり；
ｋ５は０以上１以下の整数であり；
複数のＡ^１～Ａ^５は、同一であっても異なっていてもよい。
式（１’）におけるＡ^１～Ａ^５は、ｋ１～ｋ５の定義は、式（１）と同じである。ただし、ｋ１～ｋ５の合計は０以上の整数である。
したがって、本発明の一態様にかかる有機電界発光素子用材料は、式（１’）におけるｋ１～ｋ５の合計が０である、すなわち、無置換の縮合環化合物が含まれる。

In formula (1'),
A ¹ to A ⁵ each independently represent a charge transporting 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;
A ¹ to A ⁵ may be the same or different.
In formula (1'), the definitions of k1 to k5 for A ¹ to A ⁵ are the same as those in formula (1), provided that the sum of k1 to k5 is an integer of 0 or more.
Therefore, the material for organic electroluminescent devices according to one aspect of the present invention includes an unsubstituted fused ring compound in which the sum of k1 to k5 in formula (1') is 0.

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. This 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.

In addition, 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 structure analysis, with the stacking distance being approximately 3.8 to 3.9 Å, and therefore has good orientation.

It is speculated that these structural characteristics contribute to the function of the material as an organic electroluminescent material, as described below.

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

(i): anode/light-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-generating layer/hole-transport layer/light-emitting layer/electron-transport layer/cathode

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

The organic electroluminescent device shown in FIG. 1 has a so-called bottom-emission type element configuration, but the organic electroluminescent device according to one aspect of the present invention is not limited to a bottom-emission type element configuration. In other words, the organic electroluminescent device according to one aspect of the present invention may have a top-emission type element configuration or other known element configurations.

The organic electroluminescent device 100 comprises 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.

In addition, 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 in a single layer, may be provided instead of the multiple layers. Furthermore, for example, the single-layer hole transport layer 5 and the single-layer electron transport layer 7 may each be made up of multiple layers.

[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 Figure 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').

The fused ring compound (1') may be contained in multiple layers of the organic electroluminescent device, and 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').

Hereinafter, we will explain the organic electroluminescent device 100 in which the electron transport layer 7 contains the fused ring compound (1').

[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.

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), etc.

[Anode 2]
An anode 2 is provided on the substrate 1 (on the side of the hole injection layer 3).
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.

Transparent materials used for the anode are not particularly limited, but examples 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.

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.

[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.

The hole injection layer and hole transport layer have the function of transporting holes injected from the anode to the light-emitting layer, and by interposing this hole injection layer and hole transport layer between the anode and the light-emitting layer, more holes are injected into the light-emitting layer with a lower electric field.

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 within the light-emitting layer, which brings about effects such as improved current efficiency, and an organic electroluminescent element with excellent light-emitting performance is obtained.

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 organic or inorganic.

Specific examples of materials for the hole injection layer and 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, and styrylamine compounds. Among these, porphyrin compounds, aromatic tertiary amine compounds, and styrylamine compounds are preferred, and aromatic tertiary amine compounds are particularly preferred.

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 the di(4-methoxyphenyl)-4,4'-diaminobiphenyl include 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.

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

[Charge Generation Layer 4]
A charge generating layer 4 may be provided between the hole injection layer 3 and the hole transport layer 5 .
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.

[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 recombine, resulting in light emission.

The light-emitting layer may consist of a single small molecule material or a 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.

Examples of host materials 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.

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

Examples of phosphorescent dopants include organometallic complexes of transition metals such as iridium, platinum, palladium, and osmium.

Specific examples of fluorescent 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))).

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.

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

[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').

In addition to the condensed ring compound (1'), the electron transport layer may further contain a conventionally known electron transport material. 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, and bis(2-methyl-8-quinolinato)-1-naphthol. bis(2-methyl-8-quinolinate)-2-naphtholate gallium, 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-quinolinate)-4-(phenylphenolate)aluminum), and bis(10-hydroxybenzo[h]quinolinate)beryllium).

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').

[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 formed from any conductive material.

Examples of the material for the cathode include sodium, sodium-potassium alloy, magnesium, lithium, a magnesium/copper mixture, a magnesium/silver mixture, a magnesium/aluminum mixture, a magnesium/indium mixture, an aluminum/aluminum oxide (Al ₂ O ₃ ) mixture, indium, a lithium/aluminum mixture, a rare earth metal, etc. A buffer layer (electrode interface layer) may be provided on the cathode (on the electron transport layer side).

[Method of forming each layer]
Each layer except for the electrodes (anode and cathode) described above can be formed by forming a thin film from the material of each layer (together with a material such as a binder resin and a solvent, if necessary) 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 is no particular restriction on the thickness of each layer thus formed, and it can be appropriately selected depending on the circumstances, but it is usually in the range of 5 nm to 5 μm.

The anode and cathode can be formed by forming a thin film of the electrode material by a method such as vapor deposition or sputtering. A pattern may be formed through a mask of the desired shape during vapor deposition or sputtering, or a thin film may be formed by vapor deposition or sputtering, and then a pattern of the desired shape may be formed by photolithography.

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

The organic electroluminescent device according to one aspect of the present invention may be used as a type of lamp for illumination or exposure light sources, or as a projection device that projects images, or as a display device (display) that directly displays still or moving images.

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 types of organic electroluminescent devices of this embodiment having different emission colors, it is possible to produce a full-color display device.

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

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

式（３）中、
Ａ^１～Ａ^５は、それぞれ独立して、電荷輸送性基を表し；
ｋ１～ｋ３は、それぞれ独立して、０以上４以下の整数であり；
ｋ４は０以上３以下の整数であり；
ｋ５は０以上１以下の整数であり；
複数のＡ^１～Ａ^５は、同一であっても異なっていてもよく；
Ｔは下記の式（４）または（４’）を表す；

In formula (3),
A ¹ to A ⁵ each independently represent a charge transporting 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;
A ¹ to A ⁵ may be the same or different;
T represents the following formula (4) or (4′):

式（４）および（４’）中、
Ｒ^１～Ｒ^９は水素原子または炭素数１～１２のアルキル基を表す。
式（３）におけるＡ^１～Ａ^５、ｋ１～ｋ５の定義は、式（１）と同じである。
式（４）におけるＲ^１～Ｒ^９の定義は、式（２）および（２’）におけるＲ^１～Ｒ^３と同じである。

In formulas (4) and (4′),
R ¹ to R ⁹ each represent a hydrogen atom or an alkyl group having 1 to 12 carbon atoms.
The definitions of A ¹ to A ⁵ and k1 to k5 in formula (3) are the same as those in formula (1).
The definitions of R ¹ to R ⁹ in formula (4) are the same as those of R ¹ to R ³ in formulas (2) and (2′).

<Reaction of the compound represented by formula (3)>
The compound represented by formula (3) can be reacted in the presence of a Lewis acid to obtain the 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.

The Lewis acid is not particularly limited, but from the viewpoint of yield, examples thereof include 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 ). Among these, from the viewpoint of yield, boron trifluoride diethyl ether complex ( _BF3.OEt2 ), _aluminum chloride ( _AlCl3 ), trimethyliodosilane, iron bromide (III) ( _FeBr3 ), and iron chloride (III) ( _FeCl3 ) are preferred, _with boron trifluoride diethyl ether complex ( _BF3.OEt2 ) being more preferred.

Examples of solvents include tetrahydrofuran, toluene, dimethyl sulfoxide, 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.

From the viewpoint of yield, the reaction temperature is preferably -20°C or higher and 100°C or lower, more preferably 0°C or higher and 80°C or lower, and particularly preferably 0°C or higher and 30°C or lower. From the viewpoint of suppressing the decomposition of the Lewis acid, the reaction atmosphere is preferably a dry nitrogen or dry argon atmosphere.

The present invention will be described in more detail below with reference to examples, but the present invention should not be construed as being limited in any way by these examples.

¹ H-NMR measurements were carried out using Gemini 200 (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).

Synthesis Example 1: Synthesis of compound (1-73)

窒素気流下、５０ｍＬの二口フラスコに、３－（２－ブロモー４－クロロフェニル）フルオランテン（３．５２ｇ，９．０ｍｍоｌ）、４－クロロー［２－（ピロリジンー１－イルジアゼニル）フェニル］ボロン酸（２．７７ｇ，１０．８ｍｍоｌ），ジクロロ(１，１’-ビス(ジフェニルホスフィノ)フェロセン)パラジウム（１４８ｍｇ，０．２０ｍｍоｌ）、テトラヒドロフラン（９ｍＬ）、および４Ｍの水酸化ナトリウム水溶液（４ｍＬ）を加え、７０℃で２日間攪拌した。室温まで冷却後、水層と有機層を分液し、得られた有機層を無水硫酸ナトリウムで乾燥後、減圧下で濃縮し、再沈殿（トルエン／ヘキサン）により３－｛４－クロロー２－［３－クロロー６－（ピロリジンー１－イルジアゼニル）フェニル］フェニル｝フルオランテンを含む黄色粉末を２．０ｇ得た。得られた粉末をそのまま次の工程へ使用した。

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 obtained 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.

Example 1: Synthesis of compound (1d-2)

窒素気流下、２０ｍＬの二口フラスコに、合成例１で得た粉末（２．０ｇ）、ＢＦ_３・ＯＥｔ_２（０．７０ｇ，５．０ｍｍоｌ）、およびジクロロメタン（４ｍＬ）を加え、室温で３０分間攪拌した。純水（４ｍＬ）を添加した後、析出した固体をろ過で回収した。得られた固体を再結晶（トルエン）することで、化合物（１ｄ－２）を０．５０ｇ（１．１９ｍｍоｌ）を得た（ＨＰＬＣ純度９９．６％）。
化合物の同定は^１Ｈ－ＮＭＲ測定により行った。
^１Ｈ－ＮＭＲ（ＣＤＣｌ_３）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）

Under a nitrogen stream, the powder (2.0 g) obtained in Synthesis Example 1, BF ₃ ·OEt ₂ (0.70 g, 5.0 mmol), and dichloromethane (4 mL) were added to a 20 mL two-neck flask and stirred at room temperature for 30 minutes. After adding pure water (4 mL), the precipitated solid was collected by filtration. The obtained solid was recrystallized (toluene) to obtain 0.50 g (1.19 mmol) of compound (1d-2) (HPLC purity 99.6%).
The compound was identified by ¹ H-NMR measurement.
¹ H-NMR (CDCl ₃ ) 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)

Example 2: Synthesis of compound (1d-27)

窒素気流下、２０ｍＬの二口フラスコに、化合物（１ｄ－２）（０．５６ｇ，１．３３ｍｍоｌ）、フェニルボロン酸（０．３６ｇ，２．９３ｍｍоｌ）、酢酸パラジウム（６．１ｍｇ，０．０２７ｍｍоｌ）、Ｘｐｈｏｓ ２５．８ｍｇ（０．０５３ｍｍｏｌ）、テトラヒドロフラン（１５ｍＬ）、および２Ｍの炭酸カリウム水溶液（５ｍＬ）を加え、７０℃で６時間攪拌した。室温まで冷却後、水層と有機層を分液し、得られた有機層を無水硫酸ナトリウムで乾燥後、減圧下で濃縮した。濃縮物を再結晶（トルエン）することで、化合物（１ｄ－２７）を０．５０ｇ（０．９９ｍｍоｌ）を得た（収率７４．４％，ＨＰＬＣ純度９９．９％）。
化合物の同定は^１Ｈ－ＮＭＲ測定により行った。
^１Ｈ－ＮＭＲ（ＣＤＣｌ_３）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）

Under a nitrogen stream, 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, 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 then 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%).
The compound was identified by ¹ H-NMR measurement.
¹ H-NMR (CDCl ₃ ) 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)

Then, the obtained compound was used to carry out element evaluation.

Element Example 1 (see FIG. 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 having an anode on its surface. The substrate was then washed with isopropyl alcohol and then subjected to surface treatment by ozone ultraviolet cleaning.

(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 the pressure was reduced to 1.0×10 ⁻⁴ Pa. Then, each layer was prepared according to the film formation conditions in the following order.

(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 formed into a film of 10 nm at a rate of 0.15 nm/sec to prepare hole injection layer 103.

(Preparation of 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 .

(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 .

(Fabrication of 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 film of 20 nm, thereby producing the light-emitting layer 106. The film formation rate was 0.18 nm/sec.

(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 rate of 0.05 nm/sec to prepare a first electron transport layer 1071 .

(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 film of 25 nm, thereby preparing a second electron transport layer 1072. The film formation rate was 0.15 nm/sec.

(Fabrication 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 in which silver/magnesium (mass ratio 1/10) and silver were formed in this order to thicknesses of 80 nm and 20 nm, respectively. The film formation rate of silver/magnesium was 0.5 nm/sec, and the film formation rate of silver was 0.2 nm/sec.

In this manner, an organic electroluminescent device 100 having a light-emitting area of 4 ^mm2 was produced as shown in Fig. 2. The thickness of each film was measured using a stylus film thickness meter (DEKTAK, manufactured by Bruker).

The device was then sealed in a nitrogen atmosphere glove box with oxygen and moisture concentrations of 1 ppm or less. The glass sealing cap and the film-formed substrate (device) were sealed using bisphenol F epoxy resin (manufactured by Nagase ChemteX Corporation).

A direct current was applied to the organic electroluminescent device prepared as described above, and the light emission characteristics were evaluated using a luminance meter (product name: BM-9, manufactured by Topcon Technohouse). As the light emission characteristics, the current efficiency (cd/A) when a current density of 10 mA/ ^cm2 was applied was measured, and the element life (h) during continuous lighting was measured. The element life (h) was measured by measuring the luminance decay time during continuous lighting when the prepared element was driven at an initial luminance of 1000 cd/ ^m2 , and measuring the time required for the luminance (cd/ ^m2 ) to decrease by 5%.

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

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), respectively, and evaluated. The measurement results are shown in Table 1.

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

REFERENCE SIGNS LIST 1, 101 Substrate 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 (8)

A fused ring compound represented by formula (1):

(In formula (1),
A ¹ to A ⁵ each independently represent a charge transporting 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;
A ¹ to 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. The fused ring compound according to claim 1, wherein the sum of k1 to k5 is 1 or more and 3 or less. The fused ring compound according to claim 1, wherein the sum of k1 to k5 is 1 or more and 2 or less. The fused ring compound according to any one of claims 1 to 3, having a LUMO value of 1.8 to 2.6 eV. A charge transport material for an organic electroluminescent device, comprising a fused ring compound represented by formula (1'):

(In formula (1'),
A ¹ to A ⁵ each independently represent a charge transporting 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;
A ¹ to 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. An electron transport material for organic electroluminescent devices comprising the fused ring compound according to claim 5. An organic electroluminescent device comprising the fused ring compound according to claim 5. 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).

(In formula (1),
A ¹ to A ⁵ each independently represent a charge transporting 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;
A ¹ to 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.

(In formula (3),
A ¹ to A ⁵ each independently represent a charge transporting 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;
A ¹ to 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′):

In formulas (4) and (4′),
R ¹ to R ⁹ each represent a hydrogen atom or an alkyl group having 1 to 12 carbon atoms.

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